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authorDean Nelson <dcn@sgi.com>2008-04-22 15:46:56 -0400
committerTony Luck <tony.luck@intel.com>2008-04-22 18:08:17 -0400
commit45d9ca492e4bd1522d1b5bd125c2908f1cee3d4a (patch)
treedfbe831a5f71159855c3a252856664411ca53f8a /arch/ia64/sn
parent9010eff0eadfe4eb60c3f0c71573f0fc505c31e3 (diff)
[IA64] move XP and XPC to drivers/misc/sgi-xp
Move XPC and XPNET from arch/ia64/sn/kernel to drivers/misc/sgi-xp. Signed-off-by: Dean Nelson <dcn@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/sn')
-rw-r--r--arch/ia64/sn/kernel/Makefile7
-rw-r--r--arch/ia64/sn/kernel/xp_main.c290
-rw-r--r--arch/ia64/sn/kernel/xp_nofault.S36
-rw-r--r--arch/ia64/sn/kernel/xpc_channel.c2379
-rw-r--r--arch/ia64/sn/kernel/xpc_main.c1431
-rw-r--r--arch/ia64/sn/kernel/xpc_partition.c1239
-rw-r--r--arch/ia64/sn/kernel/xpnet.c718
7 files changed, 1 insertions, 6099 deletions
diff --git a/arch/ia64/sn/kernel/Makefile b/arch/ia64/sn/kernel/Makefile
index 688a3c27e0f6..0591038735af 100644
--- a/arch/ia64/sn/kernel/Makefile
+++ b/arch/ia64/sn/kernel/Makefile
@@ -4,7 +4,7 @@
4# License. See the file "COPYING" in the main directory of this archive 4# License. See the file "COPYING" in the main directory of this archive
5# for more details. 5# for more details.
6# 6#
7# Copyright (C) 1999,2001-2006 Silicon Graphics, Inc. All Rights Reserved. 7# Copyright (C) 1999,2001-2006,2008 Silicon Graphics, Inc. All Rights Reserved.
8# 8#
9 9
10EXTRA_CFLAGS += -Iarch/ia64/sn/include 10EXTRA_CFLAGS += -Iarch/ia64/sn/include
@@ -15,9 +15,4 @@ obj-y += setup.o bte.o bte_error.o irq.o mca.o idle.o \
15 sn2/ 15 sn2/
16obj-$(CONFIG_IA64_GENERIC) += machvec.o 16obj-$(CONFIG_IA64_GENERIC) += machvec.o
17obj-$(CONFIG_SGI_TIOCX) += tiocx.o 17obj-$(CONFIG_SGI_TIOCX) += tiocx.o
18obj-$(CONFIG_IA64_SGI_SN_XP) += xp.o
19xp-y := xp_main.o xp_nofault.o
20obj-$(CONFIG_IA64_SGI_SN_XP) += xpc.o
21xpc-y := xpc_main.o xpc_channel.o xpc_partition.o
22obj-$(CONFIG_IA64_SGI_SN_XP) += xpnet.o
23obj-$(CONFIG_PCI_MSI) += msi_sn.o 18obj-$(CONFIG_PCI_MSI) += msi_sn.o
diff --git a/arch/ia64/sn/kernel/xp_main.c b/arch/ia64/sn/kernel/xp_main.c
deleted file mode 100644
index b7ea46645e12..000000000000
--- a/arch/ia64/sn/kernel/xp_main.c
+++ /dev/null
@@ -1,290 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2005 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9
10/*
11 * Cross Partition (XP) base.
12 *
13 * XP provides a base from which its users can interact
14 * with XPC, yet not be dependent on XPC.
15 *
16 */
17
18
19#include <linux/kernel.h>
20#include <linux/interrupt.h>
21#include <linux/module.h>
22#include <linux/mutex.h>
23#include <asm/sn/intr.h>
24#include <asm/sn/sn_sal.h>
25#include <asm/sn/xp.h>
26
27
28/*
29 * Target of nofault PIO read.
30 */
31u64 xp_nofault_PIOR_target;
32
33
34/*
35 * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
36 * users of XPC.
37 */
38struct xpc_registration xpc_registrations[XPC_NCHANNELS];
39
40
41/*
42 * Initialize the XPC interface to indicate that XPC isn't loaded.
43 */
44static enum xpc_retval xpc_notloaded(void) { return xpcNotLoaded; }
45
46struct xpc_interface xpc_interface = {
47 (void (*)(int)) xpc_notloaded,
48 (void (*)(int)) xpc_notloaded,
49 (enum xpc_retval (*)(partid_t, int, u32, void **)) xpc_notloaded,
50 (enum xpc_retval (*)(partid_t, int, void *)) xpc_notloaded,
51 (enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func, void *))
52 xpc_notloaded,
53 (void (*)(partid_t, int, void *)) xpc_notloaded,
54 (enum xpc_retval (*)(partid_t, void *)) xpc_notloaded
55};
56
57
58/*
59 * XPC calls this when it (the XPC module) has been loaded.
60 */
61void
62xpc_set_interface(void (*connect)(int),
63 void (*disconnect)(int),
64 enum xpc_retval (*allocate)(partid_t, int, u32, void **),
65 enum xpc_retval (*send)(partid_t, int, void *),
66 enum xpc_retval (*send_notify)(partid_t, int, void *,
67 xpc_notify_func, void *),
68 void (*received)(partid_t, int, void *),
69 enum xpc_retval (*partid_to_nasids)(partid_t, void *))
70{
71 xpc_interface.connect = connect;
72 xpc_interface.disconnect = disconnect;
73 xpc_interface.allocate = allocate;
74 xpc_interface.send = send;
75 xpc_interface.send_notify = send_notify;
76 xpc_interface.received = received;
77 xpc_interface.partid_to_nasids = partid_to_nasids;
78}
79
80
81/*
82 * XPC calls this when it (the XPC module) is being unloaded.
83 */
84void
85xpc_clear_interface(void)
86{
87 xpc_interface.connect = (void (*)(int)) xpc_notloaded;
88 xpc_interface.disconnect = (void (*)(int)) xpc_notloaded;
89 xpc_interface.allocate = (enum xpc_retval (*)(partid_t, int, u32,
90 void **)) xpc_notloaded;
91 xpc_interface.send = (enum xpc_retval (*)(partid_t, int, void *))
92 xpc_notloaded;
93 xpc_interface.send_notify = (enum xpc_retval (*)(partid_t, int, void *,
94 xpc_notify_func, void *)) xpc_notloaded;
95 xpc_interface.received = (void (*)(partid_t, int, void *))
96 xpc_notloaded;
97 xpc_interface.partid_to_nasids = (enum xpc_retval (*)(partid_t, void *))
98 xpc_notloaded;
99}
100
101
102/*
103 * Register for automatic establishment of a channel connection whenever
104 * a partition comes up.
105 *
106 * Arguments:
107 *
108 * ch_number - channel # to register for connection.
109 * func - function to call for asynchronous notification of channel
110 * state changes (i.e., connection, disconnection, error) and
111 * the arrival of incoming messages.
112 * key - pointer to optional user-defined value that gets passed back
113 * to the user on any callouts made to func.
114 * payload_size - size in bytes of the XPC message's payload area which
115 * contains a user-defined message. The user should make
116 * this large enough to hold their largest message.
117 * nentries - max #of XPC message entries a message queue can contain.
118 * The actual number, which is determined when a connection
119 * is established and may be less then requested, will be
120 * passed to the user via the xpcConnected callout.
121 * assigned_limit - max number of kthreads allowed to be processing
122 * messages (per connection) at any given instant.
123 * idle_limit - max number of kthreads allowed to be idle at any given
124 * instant.
125 */
126enum xpc_retval
127xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
128 u16 nentries, u32 assigned_limit, u32 idle_limit)
129{
130 struct xpc_registration *registration;
131
132
133 DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
134 DBUG_ON(payload_size == 0 || nentries == 0);
135 DBUG_ON(func == NULL);
136 DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
137
138 registration = &xpc_registrations[ch_number];
139
140 if (mutex_lock_interruptible(&registration->mutex) != 0) {
141 return xpcInterrupted;
142 }
143
144 /* if XPC_CHANNEL_REGISTERED(ch_number) */
145 if (registration->func != NULL) {
146 mutex_unlock(&registration->mutex);
147 return xpcAlreadyRegistered;
148 }
149
150 /* register the channel for connection */
151 registration->msg_size = XPC_MSG_SIZE(payload_size);
152 registration->nentries = nentries;
153 registration->assigned_limit = assigned_limit;
154 registration->idle_limit = idle_limit;
155 registration->key = key;
156 registration->func = func;
157
158 mutex_unlock(&registration->mutex);
159
160 xpc_interface.connect(ch_number);
161
162 return xpcSuccess;
163}
164
165
166/*
167 * Remove the registration for automatic connection of the specified channel
168 * when a partition comes up.
169 *
170 * Before returning this xpc_disconnect() will wait for all connections on the
171 * specified channel have been closed/torndown. So the caller can be assured
172 * that they will not be receiving any more callouts from XPC to their
173 * function registered via xpc_connect().
174 *
175 * Arguments:
176 *
177 * ch_number - channel # to unregister.
178 */
179void
180xpc_disconnect(int ch_number)
181{
182 struct xpc_registration *registration;
183
184
185 DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
186
187 registration = &xpc_registrations[ch_number];
188
189 /*
190 * We've decided not to make this a down_interruptible(), since we
191 * figured XPC's users will just turn around and call xpc_disconnect()
192 * again anyways, so we might as well wait, if need be.
193 */
194 mutex_lock(&registration->mutex);
195
196 /* if !XPC_CHANNEL_REGISTERED(ch_number) */
197 if (registration->func == NULL) {
198 mutex_unlock(&registration->mutex);
199 return;
200 }
201
202 /* remove the connection registration for the specified channel */
203 registration->func = NULL;
204 registration->key = NULL;
205 registration->nentries = 0;
206 registration->msg_size = 0;
207 registration->assigned_limit = 0;
208 registration->idle_limit = 0;
209
210 xpc_interface.disconnect(ch_number);
211
212 mutex_unlock(&registration->mutex);
213
214 return;
215}
216
217
218int __init
219xp_init(void)
220{
221 int ret, ch_number;
222 u64 func_addr = *(u64 *) xp_nofault_PIOR;
223 u64 err_func_addr = *(u64 *) xp_error_PIOR;
224
225
226 if (!ia64_platform_is("sn2")) {
227 return -ENODEV;
228 }
229
230 /*
231 * Register a nofault code region which performs a cross-partition
232 * PIO read. If the PIO read times out, the MCA handler will consume
233 * the error and return to a kernel-provided instruction to indicate
234 * an error. This PIO read exists because it is guaranteed to timeout
235 * if the destination is down (AMO operations do not timeout on at
236 * least some CPUs on Shubs <= v1.2, which unfortunately we have to
237 * work around).
238 */
239 if ((ret = sn_register_nofault_code(func_addr, err_func_addr,
240 err_func_addr, 1, 1)) != 0) {
241 printk(KERN_ERR "XP: can't register nofault code, error=%d\n",
242 ret);
243 }
244 /*
245 * Setup the nofault PIO read target. (There is no special reason why
246 * SH_IPI_ACCESS was selected.)
247 */
248 if (is_shub2()) {
249 xp_nofault_PIOR_target = SH2_IPI_ACCESS0;
250 } else {
251 xp_nofault_PIOR_target = SH1_IPI_ACCESS;
252 }
253
254 /* initialize the connection registration mutex */
255 for (ch_number = 0; ch_number < XPC_NCHANNELS; ch_number++) {
256 mutex_init(&xpc_registrations[ch_number].mutex);
257 }
258
259 return 0;
260}
261module_init(xp_init);
262
263
264void __exit
265xp_exit(void)
266{
267 u64 func_addr = *(u64 *) xp_nofault_PIOR;
268 u64 err_func_addr = *(u64 *) xp_error_PIOR;
269
270
271 /* unregister the PIO read nofault code region */
272 (void) sn_register_nofault_code(func_addr, err_func_addr,
273 err_func_addr, 1, 0);
274}
275module_exit(xp_exit);
276
277
278MODULE_AUTHOR("Silicon Graphics, Inc.");
279MODULE_DESCRIPTION("Cross Partition (XP) base");
280MODULE_LICENSE("GPL");
281
282EXPORT_SYMBOL(xp_nofault_PIOR);
283EXPORT_SYMBOL(xp_nofault_PIOR_target);
284EXPORT_SYMBOL(xpc_registrations);
285EXPORT_SYMBOL(xpc_interface);
286EXPORT_SYMBOL(xpc_clear_interface);
287EXPORT_SYMBOL(xpc_set_interface);
288EXPORT_SYMBOL(xpc_connect);
289EXPORT_SYMBOL(xpc_disconnect);
290
diff --git a/arch/ia64/sn/kernel/xp_nofault.S b/arch/ia64/sn/kernel/xp_nofault.S
deleted file mode 100644
index 98e7c7dbfdd8..000000000000
--- a/arch/ia64/sn/kernel/xp_nofault.S
+++ /dev/null
@@ -1,36 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2007 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9
10/*
11 * The xp_nofault_PIOR function takes a pointer to a remote PIO register
12 * and attempts to load and consume a value from it. This function
13 * will be registered as a nofault code block. In the event that the
14 * PIO read fails, the MCA handler will force the error to look
15 * corrected and vector to the xp_error_PIOR which will return an error.
16 *
17 * The definition of "consumption" and the time it takes for an MCA
18 * to surface is processor implementation specific. This code
19 * is sufficient on Itanium through the Montvale processor family.
20 * It may need to be adjusted for future processor implementations.
21 *
22 * extern int xp_nofault_PIOR(void *remote_register);
23 */
24
25 .global xp_nofault_PIOR
26xp_nofault_PIOR:
27 mov r8=r0 // Stage a success return value
28 ld8.acq r9=[r32];; // PIO Read the specified register
29 adds r9=1,r9;; // Add to force consumption
30 srlz.i;; // Allow time for MCA to surface
31 br.ret.sptk.many b0;; // Return success
32
33 .global xp_error_PIOR
34xp_error_PIOR:
35 mov r8=1 // Return value of 1
36 br.ret.sptk.many b0;; // Return failure
diff --git a/arch/ia64/sn/kernel/xpc_channel.c b/arch/ia64/sn/kernel/xpc_channel.c
deleted file mode 100644
index 44ccc0d789c9..000000000000
--- a/arch/ia64/sn/kernel/xpc_channel.c
+++ /dev/null
@@ -1,2379 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9
10/*
11 * Cross Partition Communication (XPC) channel support.
12 *
13 * This is the part of XPC that manages the channels and
14 * sends/receives messages across them to/from other partitions.
15 *
16 */
17
18
19#include <linux/kernel.h>
20#include <linux/init.h>
21#include <linux/sched.h>
22#include <linux/cache.h>
23#include <linux/interrupt.h>
24#include <linux/mutex.h>
25#include <linux/completion.h>
26#include <asm/sn/bte.h>
27#include <asm/sn/sn_sal.h>
28#include <asm/sn/xpc.h>
29
30
31/*
32 * Guarantee that the kzalloc'd memory is cacheline aligned.
33 */
34static void *
35xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
36{
37 /* see if kzalloc will give us cachline aligned memory by default */
38 *base = kzalloc(size, flags);
39 if (*base == NULL) {
40 return NULL;
41 }
42 if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) {
43 return *base;
44 }
45 kfree(*base);
46
47 /* nope, we'll have to do it ourselves */
48 *base = kzalloc(size + L1_CACHE_BYTES, flags);
49 if (*base == NULL) {
50 return NULL;
51 }
52 return (void *) L1_CACHE_ALIGN((u64) *base);
53}
54
55
56/*
57 * Set up the initial values for the XPartition Communication channels.
58 */
59static void
60xpc_initialize_channels(struct xpc_partition *part, partid_t partid)
61{
62 int ch_number;
63 struct xpc_channel *ch;
64
65
66 for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
67 ch = &part->channels[ch_number];
68
69 ch->partid = partid;
70 ch->number = ch_number;
71 ch->flags = XPC_C_DISCONNECTED;
72
73 ch->local_GP = &part->local_GPs[ch_number];
74 ch->local_openclose_args =
75 &part->local_openclose_args[ch_number];
76
77 atomic_set(&ch->kthreads_assigned, 0);
78 atomic_set(&ch->kthreads_idle, 0);
79 atomic_set(&ch->kthreads_active, 0);
80
81 atomic_set(&ch->references, 0);
82 atomic_set(&ch->n_to_notify, 0);
83
84 spin_lock_init(&ch->lock);
85 mutex_init(&ch->msg_to_pull_mutex);
86 init_completion(&ch->wdisconnect_wait);
87
88 atomic_set(&ch->n_on_msg_allocate_wq, 0);
89 init_waitqueue_head(&ch->msg_allocate_wq);
90 init_waitqueue_head(&ch->idle_wq);
91 }
92}
93
94
95/*
96 * Setup the infrastructure necessary to support XPartition Communication
97 * between the specified remote partition and the local one.
98 */
99enum xpc_retval
100xpc_setup_infrastructure(struct xpc_partition *part)
101{
102 int ret, cpuid;
103 struct timer_list *timer;
104 partid_t partid = XPC_PARTID(part);
105
106
107 /*
108 * Zero out MOST of the entry for this partition. Only the fields
109 * starting with `nchannels' will be zeroed. The preceding fields must
110 * remain `viable' across partition ups and downs, since they may be
111 * referenced during this memset() operation.
112 */
113 memset(&part->nchannels, 0, sizeof(struct xpc_partition) -
114 offsetof(struct xpc_partition, nchannels));
115
116 /*
117 * Allocate all of the channel structures as a contiguous chunk of
118 * memory.
119 */
120 part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS,
121 GFP_KERNEL);
122 if (part->channels == NULL) {
123 dev_err(xpc_chan, "can't get memory for channels\n");
124 return xpcNoMemory;
125 }
126
127 part->nchannels = XPC_NCHANNELS;
128
129
130 /* allocate all the required GET/PUT values */
131
132 part->local_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
133 GFP_KERNEL, &part->local_GPs_base);
134 if (part->local_GPs == NULL) {
135 kfree(part->channels);
136 part->channels = NULL;
137 dev_err(xpc_chan, "can't get memory for local get/put "
138 "values\n");
139 return xpcNoMemory;
140 }
141
142 part->remote_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE,
143 GFP_KERNEL, &part->remote_GPs_base);
144 if (part->remote_GPs == NULL) {
145 dev_err(xpc_chan, "can't get memory for remote get/put "
146 "values\n");
147 kfree(part->local_GPs_base);
148 part->local_GPs = NULL;
149 kfree(part->channels);
150 part->channels = NULL;
151 return xpcNoMemory;
152 }
153
154
155 /* allocate all the required open and close args */
156
157 part->local_openclose_args = xpc_kzalloc_cacheline_aligned(
158 XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
159 &part->local_openclose_args_base);
160 if (part->local_openclose_args == NULL) {
161 dev_err(xpc_chan, "can't get memory for local connect args\n");
162 kfree(part->remote_GPs_base);
163 part->remote_GPs = NULL;
164 kfree(part->local_GPs_base);
165 part->local_GPs = NULL;
166 kfree(part->channels);
167 part->channels = NULL;
168 return xpcNoMemory;
169 }
170
171 part->remote_openclose_args = xpc_kzalloc_cacheline_aligned(
172 XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL,
173 &part->remote_openclose_args_base);
174 if (part->remote_openclose_args == NULL) {
175 dev_err(xpc_chan, "can't get memory for remote connect args\n");
176 kfree(part->local_openclose_args_base);
177 part->local_openclose_args = NULL;
178 kfree(part->remote_GPs_base);
179 part->remote_GPs = NULL;
180 kfree(part->local_GPs_base);
181 part->local_GPs = NULL;
182 kfree(part->channels);
183 part->channels = NULL;
184 return xpcNoMemory;
185 }
186
187
188 xpc_initialize_channels(part, partid);
189
190 atomic_set(&part->nchannels_active, 0);
191 atomic_set(&part->nchannels_engaged, 0);
192
193
194 /* local_IPI_amo were set to 0 by an earlier memset() */
195
196 /* Initialize this partitions AMO_t structure */
197 part->local_IPI_amo_va = xpc_IPI_init(partid);
198
199 spin_lock_init(&part->IPI_lock);
200
201 atomic_set(&part->channel_mgr_requests, 1);
202 init_waitqueue_head(&part->channel_mgr_wq);
203
204 sprintf(part->IPI_owner, "xpc%02d", partid);
205 ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, IRQF_SHARED,
206 part->IPI_owner, (void *) (u64) partid);
207 if (ret != 0) {
208 dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
209 "errno=%d\n", -ret);
210 kfree(part->remote_openclose_args_base);
211 part->remote_openclose_args = NULL;
212 kfree(part->local_openclose_args_base);
213 part->local_openclose_args = NULL;
214 kfree(part->remote_GPs_base);
215 part->remote_GPs = NULL;
216 kfree(part->local_GPs_base);
217 part->local_GPs = NULL;
218 kfree(part->channels);
219 part->channels = NULL;
220 return xpcLackOfResources;
221 }
222
223 /* Setup a timer to check for dropped IPIs */
224 timer = &part->dropped_IPI_timer;
225 init_timer(timer);
226 timer->function = (void (*)(unsigned long)) xpc_dropped_IPI_check;
227 timer->data = (unsigned long) part;
228 timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT;
229 add_timer(timer);
230
231 /*
232 * With the setting of the partition setup_state to XPC_P_SETUP, we're
233 * declaring that this partition is ready to go.
234 */
235 part->setup_state = XPC_P_SETUP;
236
237
238 /*
239 * Setup the per partition specific variables required by the
240 * remote partition to establish channel connections with us.
241 *
242 * The setting of the magic # indicates that these per partition
243 * specific variables are ready to be used.
244 */
245 xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs);
246 xpc_vars_part[partid].openclose_args_pa =
247 __pa(part->local_openclose_args);
248 xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va);
249 cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */
250 xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid);
251 xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid);
252 xpc_vars_part[partid].nchannels = part->nchannels;
253 xpc_vars_part[partid].magic = XPC_VP_MAGIC1;
254
255 return xpcSuccess;
256}
257
258
259/*
260 * Create a wrapper that hides the underlying mechanism for pulling a cacheline
261 * (or multiple cachelines) from a remote partition.
262 *
263 * src must be a cacheline aligned physical address on the remote partition.
264 * dst must be a cacheline aligned virtual address on this partition.
265 * cnt must be an cacheline sized
266 */
267static enum xpc_retval
268xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst,
269 const void *src, size_t cnt)
270{
271 bte_result_t bte_ret;
272
273
274 DBUG_ON((u64) src != L1_CACHE_ALIGN((u64) src));
275 DBUG_ON((u64) dst != L1_CACHE_ALIGN((u64) dst));
276 DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
277
278 if (part->act_state == XPC_P_DEACTIVATING) {
279 return part->reason;
280 }
281
282 bte_ret = xp_bte_copy((u64) src, (u64) dst, (u64) cnt,
283 (BTE_NORMAL | BTE_WACQUIRE), NULL);
284 if (bte_ret == BTE_SUCCESS) {
285 return xpcSuccess;
286 }
287
288 dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n",
289 XPC_PARTID(part), bte_ret);
290
291 return xpc_map_bte_errors(bte_ret);
292}
293
294
295/*
296 * Pull the remote per partition specific variables from the specified
297 * partition.
298 */
299enum xpc_retval
300xpc_pull_remote_vars_part(struct xpc_partition *part)
301{
302 u8 buffer[L1_CACHE_BYTES * 2];
303 struct xpc_vars_part *pulled_entry_cacheline =
304 (struct xpc_vars_part *) L1_CACHE_ALIGN((u64) buffer);
305 struct xpc_vars_part *pulled_entry;
306 u64 remote_entry_cacheline_pa, remote_entry_pa;
307 partid_t partid = XPC_PARTID(part);
308 enum xpc_retval ret;
309
310
311 /* pull the cacheline that contains the variables we're interested in */
312
313 DBUG_ON(part->remote_vars_part_pa !=
314 L1_CACHE_ALIGN(part->remote_vars_part_pa));
315 DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2);
316
317 remote_entry_pa = part->remote_vars_part_pa +
318 sn_partition_id * sizeof(struct xpc_vars_part);
319
320 remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
321
322 pulled_entry = (struct xpc_vars_part *) ((u64) pulled_entry_cacheline +
323 (remote_entry_pa & (L1_CACHE_BYTES - 1)));
324
325 ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline,
326 (void *) remote_entry_cacheline_pa,
327 L1_CACHE_BYTES);
328 if (ret != xpcSuccess) {
329 dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
330 "partition %d, ret=%d\n", partid, ret);
331 return ret;
332 }
333
334
335 /* see if they've been set up yet */
336
337 if (pulled_entry->magic != XPC_VP_MAGIC1 &&
338 pulled_entry->magic != XPC_VP_MAGIC2) {
339
340 if (pulled_entry->magic != 0) {
341 dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
342 "partition %d has bad magic value (=0x%lx)\n",
343 partid, sn_partition_id, pulled_entry->magic);
344 return xpcBadMagic;
345 }
346
347 /* they've not been initialized yet */
348 return xpcRetry;
349 }
350
351 if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) {
352
353 /* validate the variables */
354
355 if (pulled_entry->GPs_pa == 0 ||
356 pulled_entry->openclose_args_pa == 0 ||
357 pulled_entry->IPI_amo_pa == 0) {
358
359 dev_err(xpc_chan, "partition %d's XPC vars_part for "
360 "partition %d are not valid\n", partid,
361 sn_partition_id);
362 return xpcInvalidAddress;
363 }
364
365 /* the variables we imported look to be valid */
366
367 part->remote_GPs_pa = pulled_entry->GPs_pa;
368 part->remote_openclose_args_pa =
369 pulled_entry->openclose_args_pa;
370 part->remote_IPI_amo_va =
371 (AMO_t *) __va(pulled_entry->IPI_amo_pa);
372 part->remote_IPI_nasid = pulled_entry->IPI_nasid;
373 part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid;
374
375 if (part->nchannels > pulled_entry->nchannels) {
376 part->nchannels = pulled_entry->nchannels;
377 }
378
379 /* let the other side know that we've pulled their variables */
380
381 xpc_vars_part[partid].magic = XPC_VP_MAGIC2;
382 }
383
384 if (pulled_entry->magic == XPC_VP_MAGIC1) {
385 return xpcRetry;
386 }
387
388 return xpcSuccess;
389}
390
391
392/*
393 * Get the IPI flags and pull the openclose args and/or remote GPs as needed.
394 */
395static u64
396xpc_get_IPI_flags(struct xpc_partition *part)
397{
398 unsigned long irq_flags;
399 u64 IPI_amo;
400 enum xpc_retval ret;
401
402
403 /*
404 * See if there are any IPI flags to be handled.
405 */
406
407 spin_lock_irqsave(&part->IPI_lock, irq_flags);
408 if ((IPI_amo = part->local_IPI_amo) != 0) {
409 part->local_IPI_amo = 0;
410 }
411 spin_unlock_irqrestore(&part->IPI_lock, irq_flags);
412
413
414 if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) {
415 ret = xpc_pull_remote_cachelines(part,
416 part->remote_openclose_args,
417 (void *) part->remote_openclose_args_pa,
418 XPC_OPENCLOSE_ARGS_SIZE);
419 if (ret != xpcSuccess) {
420 XPC_DEACTIVATE_PARTITION(part, ret);
421
422 dev_dbg(xpc_chan, "failed to pull openclose args from "
423 "partition %d, ret=%d\n", XPC_PARTID(part),
424 ret);
425
426 /* don't bother processing IPIs anymore */
427 IPI_amo = 0;
428 }
429 }
430
431 if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) {
432 ret = xpc_pull_remote_cachelines(part, part->remote_GPs,
433 (void *) part->remote_GPs_pa,
434 XPC_GP_SIZE);
435 if (ret != xpcSuccess) {
436 XPC_DEACTIVATE_PARTITION(part, ret);
437
438 dev_dbg(xpc_chan, "failed to pull GPs from partition "
439 "%d, ret=%d\n", XPC_PARTID(part), ret);
440
441 /* don't bother processing IPIs anymore */
442 IPI_amo = 0;
443 }
444 }
445
446 return IPI_amo;
447}
448
449
450/*
451 * Allocate the local message queue and the notify queue.
452 */
453static enum xpc_retval
454xpc_allocate_local_msgqueue(struct xpc_channel *ch)
455{
456 unsigned long irq_flags;
457 int nentries;
458 size_t nbytes;
459
460
461 // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
462 // >>> iterations of the for-loop, bail if set?
463
464 // >>> should we impose a minimum #of entries? like 4 or 8?
465 for (nentries = ch->local_nentries; nentries > 0; nentries--) {
466
467 nbytes = nentries * ch->msg_size;
468 ch->local_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
469 GFP_KERNEL,
470 &ch->local_msgqueue_base);
471 if (ch->local_msgqueue == NULL) {
472 continue;
473 }
474
475 nbytes = nentries * sizeof(struct xpc_notify);
476 ch->notify_queue = kzalloc(nbytes, GFP_KERNEL);
477 if (ch->notify_queue == NULL) {
478 kfree(ch->local_msgqueue_base);
479 ch->local_msgqueue = NULL;
480 continue;
481 }
482
483 spin_lock_irqsave(&ch->lock, irq_flags);
484 if (nentries < ch->local_nentries) {
485 dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
486 "partid=%d, channel=%d\n", nentries,
487 ch->local_nentries, ch->partid, ch->number);
488
489 ch->local_nentries = nentries;
490 }
491 spin_unlock_irqrestore(&ch->lock, irq_flags);
492 return xpcSuccess;
493 }
494
495 dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
496 "queue, partid=%d, channel=%d\n", ch->partid, ch->number);
497 return xpcNoMemory;
498}
499
500
501/*
502 * Allocate the cached remote message queue.
503 */
504static enum xpc_retval
505xpc_allocate_remote_msgqueue(struct xpc_channel *ch)
506{
507 unsigned long irq_flags;
508 int nentries;
509 size_t nbytes;
510
511
512 DBUG_ON(ch->remote_nentries <= 0);
513
514 // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between
515 // >>> iterations of the for-loop, bail if set?
516
517 // >>> should we impose a minimum #of entries? like 4 or 8?
518 for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
519
520 nbytes = nentries * ch->msg_size;
521 ch->remote_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes,
522 GFP_KERNEL,
523 &ch->remote_msgqueue_base);
524 if (ch->remote_msgqueue == NULL) {
525 continue;
526 }
527
528 spin_lock_irqsave(&ch->lock, irq_flags);
529 if (nentries < ch->remote_nentries) {
530 dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
531 "partid=%d, channel=%d\n", nentries,
532 ch->remote_nentries, ch->partid, ch->number);
533
534 ch->remote_nentries = nentries;
535 }
536 spin_unlock_irqrestore(&ch->lock, irq_flags);
537 return xpcSuccess;
538 }
539
540 dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
541 "partid=%d, channel=%d\n", ch->partid, ch->number);
542 return xpcNoMemory;
543}
544
545
546/*
547 * Allocate message queues and other stuff associated with a channel.
548 *
549 * Note: Assumes all of the channel sizes are filled in.
550 */
551static enum xpc_retval
552xpc_allocate_msgqueues(struct xpc_channel *ch)
553{
554 unsigned long irq_flags;
555 enum xpc_retval ret;
556
557
558 DBUG_ON(ch->flags & XPC_C_SETUP);
559
560 if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) {
561 return ret;
562 }
563
564 if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) {
565 kfree(ch->local_msgqueue_base);
566 ch->local_msgqueue = NULL;
567 kfree(ch->notify_queue);
568 ch->notify_queue = NULL;
569 return ret;
570 }
571
572 spin_lock_irqsave(&ch->lock, irq_flags);
573 ch->flags |= XPC_C_SETUP;
574 spin_unlock_irqrestore(&ch->lock, irq_flags);
575
576 return xpcSuccess;
577}
578
579
580/*
581 * Process a connect message from a remote partition.
582 *
583 * Note: xpc_process_connect() is expecting to be called with the
584 * spin_lock_irqsave held and will leave it locked upon return.
585 */
586static void
587xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags)
588{
589 enum xpc_retval ret;
590
591
592 DBUG_ON(!spin_is_locked(&ch->lock));
593
594 if (!(ch->flags & XPC_C_OPENREQUEST) ||
595 !(ch->flags & XPC_C_ROPENREQUEST)) {
596 /* nothing more to do for now */
597 return;
598 }
599 DBUG_ON(!(ch->flags & XPC_C_CONNECTING));
600
601 if (!(ch->flags & XPC_C_SETUP)) {
602 spin_unlock_irqrestore(&ch->lock, *irq_flags);
603 ret = xpc_allocate_msgqueues(ch);
604 spin_lock_irqsave(&ch->lock, *irq_flags);
605
606 if (ret != xpcSuccess) {
607 XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags);
608 }
609 if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) {
610 return;
611 }
612
613 DBUG_ON(!(ch->flags & XPC_C_SETUP));
614 DBUG_ON(ch->local_msgqueue == NULL);
615 DBUG_ON(ch->remote_msgqueue == NULL);
616 }
617
618 if (!(ch->flags & XPC_C_OPENREPLY)) {
619 ch->flags |= XPC_C_OPENREPLY;
620 xpc_IPI_send_openreply(ch, irq_flags);
621 }
622
623 if (!(ch->flags & XPC_C_ROPENREPLY)) {
624 return;
625 }
626
627 DBUG_ON(ch->remote_msgqueue_pa == 0);
628
629 ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */
630
631 dev_info(xpc_chan, "channel %d to partition %d connected\n",
632 ch->number, ch->partid);
633
634 spin_unlock_irqrestore(&ch->lock, *irq_flags);
635 xpc_create_kthreads(ch, 1, 0);
636 spin_lock_irqsave(&ch->lock, *irq_flags);
637}
638
639
640/*
641 * Notify those who wanted to be notified upon delivery of their message.
642 */
643static void
644xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put)
645{
646 struct xpc_notify *notify;
647 u8 notify_type;
648 s64 get = ch->w_remote_GP.get - 1;
649
650
651 while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
652
653 notify = &ch->notify_queue[get % ch->local_nentries];
654
655 /*
656 * See if the notify entry indicates it was associated with
657 * a message who's sender wants to be notified. It is possible
658 * that it is, but someone else is doing or has done the
659 * notification.
660 */
661 notify_type = notify->type;
662 if (notify_type == 0 ||
663 cmpxchg(&notify->type, notify_type, 0) !=
664 notify_type) {
665 continue;
666 }
667
668 DBUG_ON(notify_type != XPC_N_CALL);
669
670 atomic_dec(&ch->n_to_notify);
671
672 if (notify->func != NULL) {
673 dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, "
674 "msg_number=%ld, partid=%d, channel=%d\n",
675 (void *) notify, get, ch->partid, ch->number);
676
677 notify->func(reason, ch->partid, ch->number,
678 notify->key);
679
680 dev_dbg(xpc_chan, "notify->func() returned, "
681 "notify=0x%p, msg_number=%ld, partid=%d, "
682 "channel=%d\n", (void *) notify, get,
683 ch->partid, ch->number);
684 }
685 }
686}
687
688
689/*
690 * Free up message queues and other stuff that were allocated for the specified
691 * channel.
692 *
693 * Note: ch->reason and ch->reason_line are left set for debugging purposes,
694 * they're cleared when XPC_C_DISCONNECTED is cleared.
695 */
696static void
697xpc_free_msgqueues(struct xpc_channel *ch)
698{
699 DBUG_ON(!spin_is_locked(&ch->lock));
700 DBUG_ON(atomic_read(&ch->n_to_notify) != 0);
701
702 ch->remote_msgqueue_pa = 0;
703 ch->func = NULL;
704 ch->key = NULL;
705 ch->msg_size = 0;
706 ch->local_nentries = 0;
707 ch->remote_nentries = 0;
708 ch->kthreads_assigned_limit = 0;
709 ch->kthreads_idle_limit = 0;
710
711 ch->local_GP->get = 0;
712 ch->local_GP->put = 0;
713 ch->remote_GP.get = 0;
714 ch->remote_GP.put = 0;
715 ch->w_local_GP.get = 0;
716 ch->w_local_GP.put = 0;
717 ch->w_remote_GP.get = 0;
718 ch->w_remote_GP.put = 0;
719 ch->next_msg_to_pull = 0;
720
721 if (ch->flags & XPC_C_SETUP) {
722 ch->flags &= ~XPC_C_SETUP;
723
724 dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
725 ch->flags, ch->partid, ch->number);
726
727 kfree(ch->local_msgqueue_base);
728 ch->local_msgqueue = NULL;
729 kfree(ch->remote_msgqueue_base);
730 ch->remote_msgqueue = NULL;
731 kfree(ch->notify_queue);
732 ch->notify_queue = NULL;
733 }
734}
735
736
737/*
738 * spin_lock_irqsave() is expected to be held on entry.
739 */
740static void
741xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags)
742{
743 struct xpc_partition *part = &xpc_partitions[ch->partid];
744 u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED);
745
746
747 DBUG_ON(!spin_is_locked(&ch->lock));
748
749 if (!(ch->flags & XPC_C_DISCONNECTING)) {
750 return;
751 }
752
753 DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
754
755 /* make sure all activity has settled down first */
756
757 if (atomic_read(&ch->kthreads_assigned) > 0 ||
758 atomic_read(&ch->references) > 0) {
759 return;
760 }
761 DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
762 !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE));
763
764 if (part->act_state == XPC_P_DEACTIVATING) {
765 /* can't proceed until the other side disengages from us */
766 if (xpc_partition_engaged(1UL << ch->partid)) {
767 return;
768 }
769
770 } else {
771
772 /* as long as the other side is up do the full protocol */
773
774 if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
775 return;
776 }
777
778 if (!(ch->flags & XPC_C_CLOSEREPLY)) {
779 ch->flags |= XPC_C_CLOSEREPLY;
780 xpc_IPI_send_closereply(ch, irq_flags);
781 }
782
783 if (!(ch->flags & XPC_C_RCLOSEREPLY)) {
784 return;
785 }
786 }
787
788 /* wake those waiting for notify completion */
789 if (atomic_read(&ch->n_to_notify) > 0) {
790 /* >>> we do callout while holding ch->lock */
791 xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put);
792 }
793
794 /* both sides are disconnected now */
795
796 if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) {
797 spin_unlock_irqrestore(&ch->lock, *irq_flags);
798 xpc_disconnect_callout(ch, xpcDisconnected);
799 spin_lock_irqsave(&ch->lock, *irq_flags);
800 }
801
802 /* it's now safe to free the channel's message queues */
803 xpc_free_msgqueues(ch);
804
805 /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */
806 ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT));
807
808 atomic_dec(&part->nchannels_active);
809
810 if (channel_was_connected) {
811 dev_info(xpc_chan, "channel %d to partition %d disconnected, "
812 "reason=%d\n", ch->number, ch->partid, ch->reason);
813 }
814
815 if (ch->flags & XPC_C_WDISCONNECT) {
816 /* we won't lose the CPU since we're holding ch->lock */
817 complete(&ch->wdisconnect_wait);
818 } else if (ch->delayed_IPI_flags) {
819 if (part->act_state != XPC_P_DEACTIVATING) {
820 /* time to take action on any delayed IPI flags */
821 spin_lock(&part->IPI_lock);
822 XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number,
823 ch->delayed_IPI_flags);
824 spin_unlock(&part->IPI_lock);
825 }
826 ch->delayed_IPI_flags = 0;
827 }
828}
829
830
831/*
832 * Process a change in the channel's remote connection state.
833 */
834static void
835xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number,
836 u8 IPI_flags)
837{
838 unsigned long irq_flags;
839 struct xpc_openclose_args *args =
840 &part->remote_openclose_args[ch_number];
841 struct xpc_channel *ch = &part->channels[ch_number];
842 enum xpc_retval reason;
843
844
845
846 spin_lock_irqsave(&ch->lock, irq_flags);
847
848again:
849
850 if ((ch->flags & XPC_C_DISCONNECTED) &&
851 (ch->flags & XPC_C_WDISCONNECT)) {
852 /*
853 * Delay processing IPI flags until thread waiting disconnect
854 * has had a chance to see that the channel is disconnected.
855 */
856 ch->delayed_IPI_flags |= IPI_flags;
857 spin_unlock_irqrestore(&ch->lock, irq_flags);
858 return;
859 }
860
861
862 if (IPI_flags & XPC_IPI_CLOSEREQUEST) {
863
864 dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received "
865 "from partid=%d, channel=%d\n", args->reason,
866 ch->partid, ch->number);
867
868 /*
869 * If RCLOSEREQUEST is set, we're probably waiting for
870 * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
871 * with this RCLOSEREQUEST in the IPI_flags.
872 */
873
874 if (ch->flags & XPC_C_RCLOSEREQUEST) {
875 DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING));
876 DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
877 DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY));
878 DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY);
879
880 DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY));
881 IPI_flags &= ~XPC_IPI_CLOSEREPLY;
882 ch->flags |= XPC_C_RCLOSEREPLY;
883
884 /* both sides have finished disconnecting */
885 xpc_process_disconnect(ch, &irq_flags);
886 DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
887 goto again;
888 }
889
890 if (ch->flags & XPC_C_DISCONNECTED) {
891 if (!(IPI_flags & XPC_IPI_OPENREQUEST)) {
892 if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo,
893 ch_number) & XPC_IPI_OPENREQUEST)) {
894
895 DBUG_ON(ch->delayed_IPI_flags != 0);
896 spin_lock(&part->IPI_lock);
897 XPC_SET_IPI_FLAGS(part->local_IPI_amo,
898 ch_number,
899 XPC_IPI_CLOSEREQUEST);
900 spin_unlock(&part->IPI_lock);
901 }
902 spin_unlock_irqrestore(&ch->lock, irq_flags);
903 return;
904 }
905
906 XPC_SET_REASON(ch, 0, 0);
907 ch->flags &= ~XPC_C_DISCONNECTED;
908
909 atomic_inc(&part->nchannels_active);
910 ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST);
911 }
912
913 IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY);
914
915 /*
916 * The meaningful CLOSEREQUEST connection state fields are:
917 * reason = reason connection is to be closed
918 */
919
920 ch->flags |= XPC_C_RCLOSEREQUEST;
921
922 if (!(ch->flags & XPC_C_DISCONNECTING)) {
923 reason = args->reason;
924 if (reason <= xpcSuccess || reason > xpcUnknownReason) {
925 reason = xpcUnknownReason;
926 } else if (reason == xpcUnregistering) {
927 reason = xpcOtherUnregistering;
928 }
929
930 XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
931
932 DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY);
933 spin_unlock_irqrestore(&ch->lock, irq_flags);
934 return;
935 }
936
937 xpc_process_disconnect(ch, &irq_flags);
938 }
939
940
941 if (IPI_flags & XPC_IPI_CLOSEREPLY) {
942
943 dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d,"
944 " channel=%d\n", ch->partid, ch->number);
945
946 if (ch->flags & XPC_C_DISCONNECTED) {
947 DBUG_ON(part->act_state != XPC_P_DEACTIVATING);
948 spin_unlock_irqrestore(&ch->lock, irq_flags);
949 return;
950 }
951
952 DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST));
953
954 if (!(ch->flags & XPC_C_RCLOSEREQUEST)) {
955 if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number)
956 & XPC_IPI_CLOSEREQUEST)) {
957
958 DBUG_ON(ch->delayed_IPI_flags != 0);
959 spin_lock(&part->IPI_lock);
960 XPC_SET_IPI_FLAGS(part->local_IPI_amo,
961 ch_number, XPC_IPI_CLOSEREPLY);
962 spin_unlock(&part->IPI_lock);
963 }
964 spin_unlock_irqrestore(&ch->lock, irq_flags);
965 return;
966 }
967
968 ch->flags |= XPC_C_RCLOSEREPLY;
969
970 if (ch->flags & XPC_C_CLOSEREPLY) {
971 /* both sides have finished disconnecting */
972 xpc_process_disconnect(ch, &irq_flags);
973 }
974 }
975
976
977 if (IPI_flags & XPC_IPI_OPENREQUEST) {
978
979 dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, "
980 "local_nentries=%d) received from partid=%d, "
981 "channel=%d\n", args->msg_size, args->local_nentries,
982 ch->partid, ch->number);
983
984 if (part->act_state == XPC_P_DEACTIVATING ||
985 (ch->flags & XPC_C_ROPENREQUEST)) {
986 spin_unlock_irqrestore(&ch->lock, irq_flags);
987 return;
988 }
989
990 if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) {
991 ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST;
992 spin_unlock_irqrestore(&ch->lock, irq_flags);
993 return;
994 }
995 DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED |
996 XPC_C_OPENREQUEST)));
997 DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
998 XPC_C_OPENREPLY | XPC_C_CONNECTED));
999
1000 /*
1001 * The meaningful OPENREQUEST connection state fields are:
1002 * msg_size = size of channel's messages in bytes
1003 * local_nentries = remote partition's local_nentries
1004 */
1005 if (args->msg_size == 0 || args->local_nentries == 0) {
1006 /* assume OPENREQUEST was delayed by mistake */
1007 spin_unlock_irqrestore(&ch->lock, irq_flags);
1008 return;
1009 }
1010
1011 ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING);
1012 ch->remote_nentries = args->local_nentries;
1013
1014
1015 if (ch->flags & XPC_C_OPENREQUEST) {
1016 if (args->msg_size != ch->msg_size) {
1017 XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
1018 &irq_flags);
1019 spin_unlock_irqrestore(&ch->lock, irq_flags);
1020 return;
1021 }
1022 } else {
1023 ch->msg_size = args->msg_size;
1024
1025 XPC_SET_REASON(ch, 0, 0);
1026 ch->flags &= ~XPC_C_DISCONNECTED;
1027
1028 atomic_inc(&part->nchannels_active);
1029 }
1030
1031 xpc_process_connect(ch, &irq_flags);
1032 }
1033
1034
1035 if (IPI_flags & XPC_IPI_OPENREPLY) {
1036
1037 dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, "
1038 "local_nentries=%d, remote_nentries=%d) received from "
1039 "partid=%d, channel=%d\n", args->local_msgqueue_pa,
1040 args->local_nentries, args->remote_nentries,
1041 ch->partid, ch->number);
1042
1043 if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
1044 spin_unlock_irqrestore(&ch->lock, irq_flags);
1045 return;
1046 }
1047 if (!(ch->flags & XPC_C_OPENREQUEST)) {
1048 XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError,
1049 &irq_flags);
1050 spin_unlock_irqrestore(&ch->lock, irq_flags);
1051 return;
1052 }
1053
1054 DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST));
1055 DBUG_ON(ch->flags & XPC_C_CONNECTED);
1056
1057 /*
1058 * The meaningful OPENREPLY connection state fields are:
1059 * local_msgqueue_pa = physical address of remote
1060 * partition's local_msgqueue
1061 * local_nentries = remote partition's local_nentries
1062 * remote_nentries = remote partition's remote_nentries
1063 */
1064 DBUG_ON(args->local_msgqueue_pa == 0);
1065 DBUG_ON(args->local_nentries == 0);
1066 DBUG_ON(args->remote_nentries == 0);
1067
1068 ch->flags |= XPC_C_ROPENREPLY;
1069 ch->remote_msgqueue_pa = args->local_msgqueue_pa;
1070
1071 if (args->local_nentries < ch->remote_nentries) {
1072 dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
1073 "remote_nentries=%d, old remote_nentries=%d, "
1074 "partid=%d, channel=%d\n",
1075 args->local_nentries, ch->remote_nentries,
1076 ch->partid, ch->number);
1077
1078 ch->remote_nentries = args->local_nentries;
1079 }
1080 if (args->remote_nentries < ch->local_nentries) {
1081 dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new "
1082 "local_nentries=%d, old local_nentries=%d, "
1083 "partid=%d, channel=%d\n",
1084 args->remote_nentries, ch->local_nentries,
1085 ch->partid, ch->number);
1086
1087 ch->local_nentries = args->remote_nentries;
1088 }
1089
1090 xpc_process_connect(ch, &irq_flags);
1091 }
1092
1093 spin_unlock_irqrestore(&ch->lock, irq_flags);
1094}
1095
1096
1097/*
1098 * Attempt to establish a channel connection to a remote partition.
1099 */
1100static enum xpc_retval
1101xpc_connect_channel(struct xpc_channel *ch)
1102{
1103 unsigned long irq_flags;
1104 struct xpc_registration *registration = &xpc_registrations[ch->number];
1105
1106
1107 if (mutex_trylock(&registration->mutex) == 0) {
1108 return xpcRetry;
1109 }
1110
1111 if (!XPC_CHANNEL_REGISTERED(ch->number)) {
1112 mutex_unlock(&registration->mutex);
1113 return xpcUnregistered;
1114 }
1115
1116 spin_lock_irqsave(&ch->lock, irq_flags);
1117
1118 DBUG_ON(ch->flags & XPC_C_CONNECTED);
1119 DBUG_ON(ch->flags & XPC_C_OPENREQUEST);
1120
1121 if (ch->flags & XPC_C_DISCONNECTING) {
1122 spin_unlock_irqrestore(&ch->lock, irq_flags);
1123 mutex_unlock(&registration->mutex);
1124 return ch->reason;
1125 }
1126
1127
1128 /* add info from the channel connect registration to the channel */
1129
1130 ch->kthreads_assigned_limit = registration->assigned_limit;
1131 ch->kthreads_idle_limit = registration->idle_limit;
1132 DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0);
1133 DBUG_ON(atomic_read(&ch->kthreads_idle) != 0);
1134 DBUG_ON(atomic_read(&ch->kthreads_active) != 0);
1135
1136 ch->func = registration->func;
1137 DBUG_ON(registration->func == NULL);
1138 ch->key = registration->key;
1139
1140 ch->local_nentries = registration->nentries;
1141
1142 if (ch->flags & XPC_C_ROPENREQUEST) {
1143 if (registration->msg_size != ch->msg_size) {
1144 /* the local and remote sides aren't the same */
1145
1146 /*
1147 * Because XPC_DISCONNECT_CHANNEL() can block we're
1148 * forced to up the registration sema before we unlock
1149 * the channel lock. But that's okay here because we're
1150 * done with the part that required the registration
1151 * sema. XPC_DISCONNECT_CHANNEL() requires that the
1152 * channel lock be locked and will unlock and relock
1153 * the channel lock as needed.
1154 */
1155 mutex_unlock(&registration->mutex);
1156 XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes,
1157 &irq_flags);
1158 spin_unlock_irqrestore(&ch->lock, irq_flags);
1159 return xpcUnequalMsgSizes;
1160 }
1161 } else {
1162 ch->msg_size = registration->msg_size;
1163
1164 XPC_SET_REASON(ch, 0, 0);
1165 ch->flags &= ~XPC_C_DISCONNECTED;
1166
1167 atomic_inc(&xpc_partitions[ch->partid].nchannels_active);
1168 }
1169
1170 mutex_unlock(&registration->mutex);
1171
1172
1173 /* initiate the connection */
1174
1175 ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING);
1176 xpc_IPI_send_openrequest(ch, &irq_flags);
1177
1178 xpc_process_connect(ch, &irq_flags);
1179
1180 spin_unlock_irqrestore(&ch->lock, irq_flags);
1181
1182 return xpcSuccess;
1183}
1184
1185
1186/*
1187 * Clear some of the msg flags in the local message queue.
1188 */
1189static inline void
1190xpc_clear_local_msgqueue_flags(struct xpc_channel *ch)
1191{
1192 struct xpc_msg *msg;
1193 s64 get;
1194
1195
1196 get = ch->w_remote_GP.get;
1197 do {
1198 msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
1199 (get % ch->local_nentries) * ch->msg_size);
1200 msg->flags = 0;
1201 } while (++get < (volatile s64) ch->remote_GP.get);
1202}
1203
1204
1205/*
1206 * Clear some of the msg flags in the remote message queue.
1207 */
1208static inline void
1209xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch)
1210{
1211 struct xpc_msg *msg;
1212 s64 put;
1213
1214
1215 put = ch->w_remote_GP.put;
1216 do {
1217 msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
1218 (put % ch->remote_nentries) * ch->msg_size);
1219 msg->flags = 0;
1220 } while (++put < (volatile s64) ch->remote_GP.put);
1221}
1222
1223
1224static void
1225xpc_process_msg_IPI(struct xpc_partition *part, int ch_number)
1226{
1227 struct xpc_channel *ch = &part->channels[ch_number];
1228 int nmsgs_sent;
1229
1230
1231 ch->remote_GP = part->remote_GPs[ch_number];
1232
1233
1234 /* See what, if anything, has changed for each connected channel */
1235
1236 xpc_msgqueue_ref(ch);
1237
1238 if (ch->w_remote_GP.get == ch->remote_GP.get &&
1239 ch->w_remote_GP.put == ch->remote_GP.put) {
1240 /* nothing changed since GPs were last pulled */
1241 xpc_msgqueue_deref(ch);
1242 return;
1243 }
1244
1245 if (!(ch->flags & XPC_C_CONNECTED)){
1246 xpc_msgqueue_deref(ch);
1247 return;
1248 }
1249
1250
1251 /*
1252 * First check to see if messages recently sent by us have been
1253 * received by the other side. (The remote GET value will have
1254 * changed since we last looked at it.)
1255 */
1256
1257 if (ch->w_remote_GP.get != ch->remote_GP.get) {
1258
1259 /*
1260 * We need to notify any senders that want to be notified
1261 * that their sent messages have been received by their
1262 * intended recipients. We need to do this before updating
1263 * w_remote_GP.get so that we don't allocate the same message
1264 * queue entries prematurely (see xpc_allocate_msg()).
1265 */
1266 if (atomic_read(&ch->n_to_notify) > 0) {
1267 /*
1268 * Notify senders that messages sent have been
1269 * received and delivered by the other side.
1270 */
1271 xpc_notify_senders(ch, xpcMsgDelivered,
1272 ch->remote_GP.get);
1273 }
1274
1275 /*
1276 * Clear msg->flags in previously sent messages, so that
1277 * they're ready for xpc_allocate_msg().
1278 */
1279 xpc_clear_local_msgqueue_flags(ch);
1280
1281 ch->w_remote_GP.get = ch->remote_GP.get;
1282
1283 dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
1284 "channel=%d\n", ch->w_remote_GP.get, ch->partid,
1285 ch->number);
1286
1287 /*
1288 * If anyone was waiting for message queue entries to become
1289 * available, wake them up.
1290 */
1291 if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
1292 wake_up(&ch->msg_allocate_wq);
1293 }
1294 }
1295
1296
1297 /*
1298 * Now check for newly sent messages by the other side. (The remote
1299 * PUT value will have changed since we last looked at it.)
1300 */
1301
1302 if (ch->w_remote_GP.put != ch->remote_GP.put) {
1303 /*
1304 * Clear msg->flags in previously received messages, so that
1305 * they're ready for xpc_get_deliverable_msg().
1306 */
1307 xpc_clear_remote_msgqueue_flags(ch);
1308
1309 ch->w_remote_GP.put = ch->remote_GP.put;
1310
1311 dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
1312 "channel=%d\n", ch->w_remote_GP.put, ch->partid,
1313 ch->number);
1314
1315 nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get;
1316 if (nmsgs_sent > 0) {
1317 dev_dbg(xpc_chan, "msgs waiting to be copied and "
1318 "delivered=%d, partid=%d, channel=%d\n",
1319 nmsgs_sent, ch->partid, ch->number);
1320
1321 if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) {
1322 xpc_activate_kthreads(ch, nmsgs_sent);
1323 }
1324 }
1325 }
1326
1327 xpc_msgqueue_deref(ch);
1328}
1329
1330
1331void
1332xpc_process_channel_activity(struct xpc_partition *part)
1333{
1334 unsigned long irq_flags;
1335 u64 IPI_amo, IPI_flags;
1336 struct xpc_channel *ch;
1337 int ch_number;
1338 u32 ch_flags;
1339
1340
1341 IPI_amo = xpc_get_IPI_flags(part);
1342
1343 /*
1344 * Initiate channel connections for registered channels.
1345 *
1346 * For each connected channel that has pending messages activate idle
1347 * kthreads and/or create new kthreads as needed.
1348 */
1349
1350 for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
1351 ch = &part->channels[ch_number];
1352
1353
1354 /*
1355 * Process any open or close related IPI flags, and then deal
1356 * with connecting or disconnecting the channel as required.
1357 */
1358
1359 IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number);
1360
1361 if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) {
1362 xpc_process_openclose_IPI(part, ch_number, IPI_flags);
1363 }
1364
1365 ch_flags = ch->flags; /* need an atomic snapshot of flags */
1366
1367 if (ch_flags & XPC_C_DISCONNECTING) {
1368 spin_lock_irqsave(&ch->lock, irq_flags);
1369 xpc_process_disconnect(ch, &irq_flags);
1370 spin_unlock_irqrestore(&ch->lock, irq_flags);
1371 continue;
1372 }
1373
1374 if (part->act_state == XPC_P_DEACTIVATING) {
1375 continue;
1376 }
1377
1378 if (!(ch_flags & XPC_C_CONNECTED)) {
1379 if (!(ch_flags & XPC_C_OPENREQUEST)) {
1380 DBUG_ON(ch_flags & XPC_C_SETUP);
1381 (void) xpc_connect_channel(ch);
1382 } else {
1383 spin_lock_irqsave(&ch->lock, irq_flags);
1384 xpc_process_connect(ch, &irq_flags);
1385 spin_unlock_irqrestore(&ch->lock, irq_flags);
1386 }
1387 continue;
1388 }
1389
1390
1391 /*
1392 * Process any message related IPI flags, this may involve the
1393 * activation of kthreads to deliver any pending messages sent
1394 * from the other partition.
1395 */
1396
1397 if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) {
1398 xpc_process_msg_IPI(part, ch_number);
1399 }
1400 }
1401}
1402
1403
1404/*
1405 * XPC's heartbeat code calls this function to inform XPC that a partition is
1406 * going down. XPC responds by tearing down the XPartition Communication
1407 * infrastructure used for the just downed partition.
1408 *
1409 * XPC's heartbeat code will never call this function and xpc_partition_up()
1410 * at the same time. Nor will it ever make multiple calls to either function
1411 * at the same time.
1412 */
1413void
1414xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason)
1415{
1416 unsigned long irq_flags;
1417 int ch_number;
1418 struct xpc_channel *ch;
1419
1420
1421 dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n",
1422 XPC_PARTID(part), reason);
1423
1424 if (!xpc_part_ref(part)) {
1425 /* infrastructure for this partition isn't currently set up */
1426 return;
1427 }
1428
1429
1430 /* disconnect channels associated with the partition going down */
1431
1432 for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
1433 ch = &part->channels[ch_number];
1434
1435 xpc_msgqueue_ref(ch);
1436 spin_lock_irqsave(&ch->lock, irq_flags);
1437
1438 XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags);
1439
1440 spin_unlock_irqrestore(&ch->lock, irq_flags);
1441 xpc_msgqueue_deref(ch);
1442 }
1443
1444 xpc_wakeup_channel_mgr(part);
1445
1446 xpc_part_deref(part);
1447}
1448
1449
1450/*
1451 * Teardown the infrastructure necessary to support XPartition Communication
1452 * between the specified remote partition and the local one.
1453 */
1454void
1455xpc_teardown_infrastructure(struct xpc_partition *part)
1456{
1457 partid_t partid = XPC_PARTID(part);
1458
1459
1460 /*
1461 * We start off by making this partition inaccessible to local
1462 * processes by marking it as no longer setup. Then we make it
1463 * inaccessible to remote processes by clearing the XPC per partition
1464 * specific variable's magic # (which indicates that these variables
1465 * are no longer valid) and by ignoring all XPC notify IPIs sent to
1466 * this partition.
1467 */
1468
1469 DBUG_ON(atomic_read(&part->nchannels_engaged) != 0);
1470 DBUG_ON(atomic_read(&part->nchannels_active) != 0);
1471 DBUG_ON(part->setup_state != XPC_P_SETUP);
1472 part->setup_state = XPC_P_WTEARDOWN;
1473
1474 xpc_vars_part[partid].magic = 0;
1475
1476
1477 free_irq(SGI_XPC_NOTIFY, (void *) (u64) partid);
1478
1479
1480 /*
1481 * Before proceeding with the teardown we have to wait until all
1482 * existing references cease.
1483 */
1484 wait_event(part->teardown_wq, (atomic_read(&part->references) == 0));
1485
1486
1487 /* now we can begin tearing down the infrastructure */
1488
1489 part->setup_state = XPC_P_TORNDOWN;
1490
1491 /* in case we've still got outstanding timers registered... */
1492 del_timer_sync(&part->dropped_IPI_timer);
1493
1494 kfree(part->remote_openclose_args_base);
1495 part->remote_openclose_args = NULL;
1496 kfree(part->local_openclose_args_base);
1497 part->local_openclose_args = NULL;
1498 kfree(part->remote_GPs_base);
1499 part->remote_GPs = NULL;
1500 kfree(part->local_GPs_base);
1501 part->local_GPs = NULL;
1502 kfree(part->channels);
1503 part->channels = NULL;
1504 part->local_IPI_amo_va = NULL;
1505}
1506
1507
1508/*
1509 * Called by XP at the time of channel connection registration to cause
1510 * XPC to establish connections to all currently active partitions.
1511 */
1512void
1513xpc_initiate_connect(int ch_number)
1514{
1515 partid_t partid;
1516 struct xpc_partition *part;
1517 struct xpc_channel *ch;
1518
1519
1520 DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
1521
1522 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
1523 part = &xpc_partitions[partid];
1524
1525 if (xpc_part_ref(part)) {
1526 ch = &part->channels[ch_number];
1527
1528 /*
1529 * Initiate the establishment of a connection on the
1530 * newly registered channel to the remote partition.
1531 */
1532 xpc_wakeup_channel_mgr(part);
1533 xpc_part_deref(part);
1534 }
1535 }
1536}
1537
1538
1539void
1540xpc_connected_callout(struct xpc_channel *ch)
1541{
1542 /* let the registerer know that a connection has been established */
1543
1544 if (ch->func != NULL) {
1545 dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, "
1546 "partid=%d, channel=%d\n", ch->partid, ch->number);
1547
1548 ch->func(xpcConnected, ch->partid, ch->number,
1549 (void *) (u64) ch->local_nentries, ch->key);
1550
1551 dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, "
1552 "partid=%d, channel=%d\n", ch->partid, ch->number);
1553 }
1554}
1555
1556
1557/*
1558 * Called by XP at the time of channel connection unregistration to cause
1559 * XPC to teardown all current connections for the specified channel.
1560 *
1561 * Before returning xpc_initiate_disconnect() will wait until all connections
1562 * on the specified channel have been closed/torndown. So the caller can be
1563 * assured that they will not be receiving any more callouts from XPC to the
1564 * function they registered via xpc_connect().
1565 *
1566 * Arguments:
1567 *
1568 * ch_number - channel # to unregister.
1569 */
1570void
1571xpc_initiate_disconnect(int ch_number)
1572{
1573 unsigned long irq_flags;
1574 partid_t partid;
1575 struct xpc_partition *part;
1576 struct xpc_channel *ch;
1577
1578
1579 DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS);
1580
1581 /* initiate the channel disconnect for every active partition */
1582 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
1583 part = &xpc_partitions[partid];
1584
1585 if (xpc_part_ref(part)) {
1586 ch = &part->channels[ch_number];
1587 xpc_msgqueue_ref(ch);
1588
1589 spin_lock_irqsave(&ch->lock, irq_flags);
1590
1591 if (!(ch->flags & XPC_C_DISCONNECTED)) {
1592 ch->flags |= XPC_C_WDISCONNECT;
1593
1594 XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering,
1595 &irq_flags);
1596 }
1597
1598 spin_unlock_irqrestore(&ch->lock, irq_flags);
1599
1600 xpc_msgqueue_deref(ch);
1601 xpc_part_deref(part);
1602 }
1603 }
1604
1605 xpc_disconnect_wait(ch_number);
1606}
1607
1608
1609/*
1610 * To disconnect a channel, and reflect it back to all who may be waiting.
1611 *
1612 * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
1613 * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by
1614 * xpc_disconnect_wait().
1615 *
1616 * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN.
1617 */
1618void
1619xpc_disconnect_channel(const int line, struct xpc_channel *ch,
1620 enum xpc_retval reason, unsigned long *irq_flags)
1621{
1622 u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED);
1623
1624
1625 DBUG_ON(!spin_is_locked(&ch->lock));
1626
1627 if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) {
1628 return;
1629 }
1630 DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED)));
1631
1632 dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n",
1633 reason, line, ch->partid, ch->number);
1634
1635 XPC_SET_REASON(ch, reason, line);
1636
1637 ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING);
1638 /* some of these may not have been set */
1639 ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY |
1640 XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY |
1641 XPC_C_CONNECTING | XPC_C_CONNECTED);
1642
1643 xpc_IPI_send_closerequest(ch, irq_flags);
1644
1645 if (channel_was_connected) {
1646 ch->flags |= XPC_C_WASCONNECTED;
1647 }
1648
1649 spin_unlock_irqrestore(&ch->lock, *irq_flags);
1650
1651 /* wake all idle kthreads so they can exit */
1652 if (atomic_read(&ch->kthreads_idle) > 0) {
1653 wake_up_all(&ch->idle_wq);
1654
1655 } else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
1656 !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
1657 /* start a kthread that will do the xpcDisconnecting callout */
1658 xpc_create_kthreads(ch, 1, 1);
1659 }
1660
1661 /* wake those waiting to allocate an entry from the local msg queue */
1662 if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) {
1663 wake_up(&ch->msg_allocate_wq);
1664 }
1665
1666 spin_lock_irqsave(&ch->lock, *irq_flags);
1667}
1668
1669
1670void
1671xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_retval reason)
1672{
1673 /*
1674 * Let the channel's registerer know that the channel is being
1675 * disconnected. We don't want to do this if the registerer was never
1676 * informed of a connection being made.
1677 */
1678
1679 if (ch->func != NULL) {
1680 dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, "
1681 "channel=%d\n", reason, ch->partid, ch->number);
1682
1683 ch->func(reason, ch->partid, ch->number, NULL, ch->key);
1684
1685 dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, "
1686 "channel=%d\n", reason, ch->partid, ch->number);
1687 }
1688}
1689
1690
1691/*
1692 * Wait for a message entry to become available for the specified channel,
1693 * but don't wait any longer than 1 jiffy.
1694 */
1695static enum xpc_retval
1696xpc_allocate_msg_wait(struct xpc_channel *ch)
1697{
1698 enum xpc_retval ret;
1699
1700
1701 if (ch->flags & XPC_C_DISCONNECTING) {
1702 DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true?
1703 return ch->reason;
1704 }
1705
1706 atomic_inc(&ch->n_on_msg_allocate_wq);
1707 ret = interruptible_sleep_on_timeout(&ch->msg_allocate_wq, 1);
1708 atomic_dec(&ch->n_on_msg_allocate_wq);
1709
1710 if (ch->flags & XPC_C_DISCONNECTING) {
1711 ret = ch->reason;
1712 DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true?
1713 } else if (ret == 0) {
1714 ret = xpcTimeout;
1715 } else {
1716 ret = xpcInterrupted;
1717 }
1718
1719 return ret;
1720}
1721
1722
1723/*
1724 * Allocate an entry for a message from the message queue associated with the
1725 * specified channel.
1726 */
1727static enum xpc_retval
1728xpc_allocate_msg(struct xpc_channel *ch, u32 flags,
1729 struct xpc_msg **address_of_msg)
1730{
1731 struct xpc_msg *msg;
1732 enum xpc_retval ret;
1733 s64 put;
1734
1735
1736 /* this reference will be dropped in xpc_send_msg() */
1737 xpc_msgqueue_ref(ch);
1738
1739 if (ch->flags & XPC_C_DISCONNECTING) {
1740 xpc_msgqueue_deref(ch);
1741 return ch->reason;
1742 }
1743 if (!(ch->flags & XPC_C_CONNECTED)) {
1744 xpc_msgqueue_deref(ch);
1745 return xpcNotConnected;
1746 }
1747
1748
1749 /*
1750 * Get the next available message entry from the local message queue.
1751 * If none are available, we'll make sure that we grab the latest
1752 * GP values.
1753 */
1754 ret = xpcTimeout;
1755
1756 while (1) {
1757
1758 put = (volatile s64) ch->w_local_GP.put;
1759 if (put - (volatile s64) ch->w_remote_GP.get <
1760 ch->local_nentries) {
1761
1762 /* There are available message entries. We need to try
1763 * to secure one for ourselves. We'll do this by trying
1764 * to increment w_local_GP.put as long as someone else
1765 * doesn't beat us to it. If they do, we'll have to
1766 * try again.
1767 */
1768 if (cmpxchg(&ch->w_local_GP.put, put, put + 1) ==
1769 put) {
1770 /* we got the entry referenced by put */
1771 break;
1772 }
1773 continue; /* try again */
1774 }
1775
1776
1777 /*
1778 * There aren't any available msg entries at this time.
1779 *
1780 * In waiting for a message entry to become available,
1781 * we set a timeout in case the other side is not
1782 * sending completion IPIs. This lets us fake an IPI
1783 * that will cause the IPI handler to fetch the latest
1784 * GP values as if an IPI was sent by the other side.
1785 */
1786 if (ret == xpcTimeout) {
1787 xpc_IPI_send_local_msgrequest(ch);
1788 }
1789
1790 if (flags & XPC_NOWAIT) {
1791 xpc_msgqueue_deref(ch);
1792 return xpcNoWait;
1793 }
1794
1795 ret = xpc_allocate_msg_wait(ch);
1796 if (ret != xpcInterrupted && ret != xpcTimeout) {
1797 xpc_msgqueue_deref(ch);
1798 return ret;
1799 }
1800 }
1801
1802
1803 /* get the message's address and initialize it */
1804 msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
1805 (put % ch->local_nentries) * ch->msg_size);
1806
1807
1808 DBUG_ON(msg->flags != 0);
1809 msg->number = put;
1810
1811 dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
1812 "msg_number=%ld, partid=%d, channel=%d\n", put + 1,
1813 (void *) msg, msg->number, ch->partid, ch->number);
1814
1815 *address_of_msg = msg;
1816
1817 return xpcSuccess;
1818}
1819
1820
1821/*
1822 * Allocate an entry for a message from the message queue associated with the
1823 * specified channel. NOTE that this routine can sleep waiting for a message
1824 * entry to become available. To not sleep, pass in the XPC_NOWAIT flag.
1825 *
1826 * Arguments:
1827 *
1828 * partid - ID of partition to which the channel is connected.
1829 * ch_number - channel #.
1830 * flags - see xpc.h for valid flags.
1831 * payload - address of the allocated payload area pointer (filled in on
1832 * return) in which the user-defined message is constructed.
1833 */
1834enum xpc_retval
1835xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
1836{
1837 struct xpc_partition *part = &xpc_partitions[partid];
1838 enum xpc_retval ret = xpcUnknownReason;
1839 struct xpc_msg *msg = NULL;
1840
1841
1842 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
1843 DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
1844
1845 *payload = NULL;
1846
1847 if (xpc_part_ref(part)) {
1848 ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg);
1849 xpc_part_deref(part);
1850
1851 if (msg != NULL) {
1852 *payload = &msg->payload;
1853 }
1854 }
1855
1856 return ret;
1857}
1858
1859
1860/*
1861 * Now we actually send the messages that are ready to be sent by advancing
1862 * the local message queue's Put value and then send an IPI to the recipient
1863 * partition.
1864 */
1865static void
1866xpc_send_msgs(struct xpc_channel *ch, s64 initial_put)
1867{
1868 struct xpc_msg *msg;
1869 s64 put = initial_put + 1;
1870 int send_IPI = 0;
1871
1872
1873 while (1) {
1874
1875 while (1) {
1876 if (put == (volatile s64) ch->w_local_GP.put) {
1877 break;
1878 }
1879
1880 msg = (struct xpc_msg *) ((u64) ch->local_msgqueue +
1881 (put % ch->local_nentries) * ch->msg_size);
1882
1883 if (!(msg->flags & XPC_M_READY)) {
1884 break;
1885 }
1886
1887 put++;
1888 }
1889
1890 if (put == initial_put) {
1891 /* nothing's changed */
1892 break;
1893 }
1894
1895 if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) !=
1896 initial_put) {
1897 /* someone else beat us to it */
1898 DBUG_ON((volatile s64) ch->local_GP->put < initial_put);
1899 break;
1900 }
1901
1902 /* we just set the new value of local_GP->put */
1903
1904 dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
1905 "channel=%d\n", put, ch->partid, ch->number);
1906
1907 send_IPI = 1;
1908
1909 /*
1910 * We need to ensure that the message referenced by
1911 * local_GP->put is not XPC_M_READY or that local_GP->put
1912 * equals w_local_GP.put, so we'll go have a look.
1913 */
1914 initial_put = put;
1915 }
1916
1917 if (send_IPI) {
1918 xpc_IPI_send_msgrequest(ch);
1919 }
1920}
1921
1922
1923/*
1924 * Common code that does the actual sending of the message by advancing the
1925 * local message queue's Put value and sends an IPI to the partition the
1926 * message is being sent to.
1927 */
1928static enum xpc_retval
1929xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type,
1930 xpc_notify_func func, void *key)
1931{
1932 enum xpc_retval ret = xpcSuccess;
1933 struct xpc_notify *notify = notify;
1934 s64 put, msg_number = msg->number;
1935
1936
1937 DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
1938 DBUG_ON((((u64) msg - (u64) ch->local_msgqueue) / ch->msg_size) !=
1939 msg_number % ch->local_nentries);
1940 DBUG_ON(msg->flags & XPC_M_READY);
1941
1942 if (ch->flags & XPC_C_DISCONNECTING) {
1943 /* drop the reference grabbed in xpc_allocate_msg() */
1944 xpc_msgqueue_deref(ch);
1945 return ch->reason;
1946 }
1947
1948 if (notify_type != 0) {
1949 /*
1950 * Tell the remote side to send an ACK interrupt when the
1951 * message has been delivered.
1952 */
1953 msg->flags |= XPC_M_INTERRUPT;
1954
1955 atomic_inc(&ch->n_to_notify);
1956
1957 notify = &ch->notify_queue[msg_number % ch->local_nentries];
1958 notify->func = func;
1959 notify->key = key;
1960 notify->type = notify_type;
1961
1962 // >>> is a mb() needed here?
1963
1964 if (ch->flags & XPC_C_DISCONNECTING) {
1965 /*
1966 * An error occurred between our last error check and
1967 * this one. We will try to clear the type field from
1968 * the notify entry. If we succeed then
1969 * xpc_disconnect_channel() didn't already process
1970 * the notify entry.
1971 */
1972 if (cmpxchg(&notify->type, notify_type, 0) ==
1973 notify_type) {
1974 atomic_dec(&ch->n_to_notify);
1975 ret = ch->reason;
1976 }
1977
1978 /* drop the reference grabbed in xpc_allocate_msg() */
1979 xpc_msgqueue_deref(ch);
1980 return ret;
1981 }
1982 }
1983
1984 msg->flags |= XPC_M_READY;
1985
1986 /*
1987 * The preceding store of msg->flags must occur before the following
1988 * load of ch->local_GP->put.
1989 */
1990 mb();
1991
1992 /* see if the message is next in line to be sent, if so send it */
1993
1994 put = ch->local_GP->put;
1995 if (put == msg_number) {
1996 xpc_send_msgs(ch, put);
1997 }
1998
1999 /* drop the reference grabbed in xpc_allocate_msg() */
2000 xpc_msgqueue_deref(ch);
2001 return ret;
2002}
2003
2004
2005/*
2006 * Send a message previously allocated using xpc_initiate_allocate() on the
2007 * specified channel connected to the specified partition.
2008 *
2009 * This routine will not wait for the message to be received, nor will
2010 * notification be given when it does happen. Once this routine has returned
2011 * the message entry allocated via xpc_initiate_allocate() is no longer
2012 * accessable to the caller.
2013 *
2014 * This routine, although called by users, does not call xpc_part_ref() to
2015 * ensure that the partition infrastructure is in place. It relies on the
2016 * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
2017 *
2018 * Arguments:
2019 *
2020 * partid - ID of partition to which the channel is connected.
2021 * ch_number - channel # to send message on.
2022 * payload - pointer to the payload area allocated via
2023 * xpc_initiate_allocate().
2024 */
2025enum xpc_retval
2026xpc_initiate_send(partid_t partid, int ch_number, void *payload)
2027{
2028 struct xpc_partition *part = &xpc_partitions[partid];
2029 struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
2030 enum xpc_retval ret;
2031
2032
2033 dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg,
2034 partid, ch_number);
2035
2036 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
2037 DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
2038 DBUG_ON(msg == NULL);
2039
2040 ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL);
2041
2042 return ret;
2043}
2044
2045
2046/*
2047 * Send a message previously allocated using xpc_initiate_allocate on the
2048 * specified channel connected to the specified partition.
2049 *
2050 * This routine will not wait for the message to be sent. Once this routine
2051 * has returned the message entry allocated via xpc_initiate_allocate() is no
2052 * longer accessable to the caller.
2053 *
2054 * Once the remote end of the channel has received the message, the function
2055 * passed as an argument to xpc_initiate_send_notify() will be called. This
2056 * allows the sender to free up or re-use any buffers referenced by the
2057 * message, but does NOT mean the message has been processed at the remote
2058 * end by a receiver.
2059 *
2060 * If this routine returns an error, the caller's function will NOT be called.
2061 *
2062 * This routine, although called by users, does not call xpc_part_ref() to
2063 * ensure that the partition infrastructure is in place. It relies on the
2064 * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg().
2065 *
2066 * Arguments:
2067 *
2068 * partid - ID of partition to which the channel is connected.
2069 * ch_number - channel # to send message on.
2070 * payload - pointer to the payload area allocated via
2071 * xpc_initiate_allocate().
2072 * func - function to call with asynchronous notification of message
2073 * receipt. THIS FUNCTION MUST BE NON-BLOCKING.
2074 * key - user-defined key to be passed to the function when it's called.
2075 */
2076enum xpc_retval
2077xpc_initiate_send_notify(partid_t partid, int ch_number, void *payload,
2078 xpc_notify_func func, void *key)
2079{
2080 struct xpc_partition *part = &xpc_partitions[partid];
2081 struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
2082 enum xpc_retval ret;
2083
2084
2085 dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg,
2086 partid, ch_number);
2087
2088 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
2089 DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
2090 DBUG_ON(msg == NULL);
2091 DBUG_ON(func == NULL);
2092
2093 ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL,
2094 func, key);
2095 return ret;
2096}
2097
2098
2099static struct xpc_msg *
2100xpc_pull_remote_msg(struct xpc_channel *ch, s64 get)
2101{
2102 struct xpc_partition *part = &xpc_partitions[ch->partid];
2103 struct xpc_msg *remote_msg, *msg;
2104 u32 msg_index, nmsgs;
2105 u64 msg_offset;
2106 enum xpc_retval ret;
2107
2108
2109 if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) {
2110 /* we were interrupted by a signal */
2111 return NULL;
2112 }
2113
2114 while (get >= ch->next_msg_to_pull) {
2115
2116 /* pull as many messages as are ready and able to be pulled */
2117
2118 msg_index = ch->next_msg_to_pull % ch->remote_nentries;
2119
2120 DBUG_ON(ch->next_msg_to_pull >=
2121 (volatile s64) ch->w_remote_GP.put);
2122 nmsgs = (volatile s64) ch->w_remote_GP.put -
2123 ch->next_msg_to_pull;
2124 if (msg_index + nmsgs > ch->remote_nentries) {
2125 /* ignore the ones that wrap the msg queue for now */
2126 nmsgs = ch->remote_nentries - msg_index;
2127 }
2128
2129 msg_offset = msg_index * ch->msg_size;
2130 msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
2131 msg_offset);
2132 remote_msg = (struct xpc_msg *) (ch->remote_msgqueue_pa +
2133 msg_offset);
2134
2135 if ((ret = xpc_pull_remote_cachelines(part, msg, remote_msg,
2136 nmsgs * ch->msg_size)) != xpcSuccess) {
2137
2138 dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
2139 " msg %ld from partition %d, channel=%d, "
2140 "ret=%d\n", nmsgs, ch->next_msg_to_pull,
2141 ch->partid, ch->number, ret);
2142
2143 XPC_DEACTIVATE_PARTITION(part, ret);
2144
2145 mutex_unlock(&ch->msg_to_pull_mutex);
2146 return NULL;
2147 }
2148
2149 mb(); /* >>> this may not be needed, we're not sure */
2150
2151 ch->next_msg_to_pull += nmsgs;
2152 }
2153
2154 mutex_unlock(&ch->msg_to_pull_mutex);
2155
2156 /* return the message we were looking for */
2157 msg_offset = (get % ch->remote_nentries) * ch->msg_size;
2158 msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + msg_offset);
2159
2160 return msg;
2161}
2162
2163
2164/*
2165 * Get a message to be delivered.
2166 */
2167static struct xpc_msg *
2168xpc_get_deliverable_msg(struct xpc_channel *ch)
2169{
2170 struct xpc_msg *msg = NULL;
2171 s64 get;
2172
2173
2174 do {
2175 if ((volatile u32) ch->flags & XPC_C_DISCONNECTING) {
2176 break;
2177 }
2178
2179 get = (volatile s64) ch->w_local_GP.get;
2180 if (get == (volatile s64) ch->w_remote_GP.put) {
2181 break;
2182 }
2183
2184 /* There are messages waiting to be pulled and delivered.
2185 * We need to try to secure one for ourselves. We'll do this
2186 * by trying to increment w_local_GP.get and hope that no one
2187 * else beats us to it. If they do, we'll we'll simply have
2188 * to try again for the next one.
2189 */
2190
2191 if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) {
2192 /* we got the entry referenced by get */
2193
2194 dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
2195 "partid=%d, channel=%d\n", get + 1,
2196 ch->partid, ch->number);
2197
2198 /* pull the message from the remote partition */
2199
2200 msg = xpc_pull_remote_msg(ch, get);
2201
2202 DBUG_ON(msg != NULL && msg->number != get);
2203 DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE));
2204 DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY));
2205
2206 break;
2207 }
2208
2209 } while (1);
2210
2211 return msg;
2212}
2213
2214
2215/*
2216 * Deliver a message to its intended recipient.
2217 */
2218void
2219xpc_deliver_msg(struct xpc_channel *ch)
2220{
2221 struct xpc_msg *msg;
2222
2223
2224 if ((msg = xpc_get_deliverable_msg(ch)) != NULL) {
2225
2226 /*
2227 * This ref is taken to protect the payload itself from being
2228 * freed before the user is finished with it, which the user
2229 * indicates by calling xpc_initiate_received().
2230 */
2231 xpc_msgqueue_ref(ch);
2232
2233 atomic_inc(&ch->kthreads_active);
2234
2235 if (ch->func != NULL) {
2236 dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, "
2237 "msg_number=%ld, partid=%d, channel=%d\n",
2238 (void *) msg, msg->number, ch->partid,
2239 ch->number);
2240
2241 /* deliver the message to its intended recipient */
2242 ch->func(xpcMsgReceived, ch->partid, ch->number,
2243 &msg->payload, ch->key);
2244
2245 dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, "
2246 "msg_number=%ld, partid=%d, channel=%d\n",
2247 (void *) msg, msg->number, ch->partid,
2248 ch->number);
2249 }
2250
2251 atomic_dec(&ch->kthreads_active);
2252 }
2253}
2254
2255
2256/*
2257 * Now we actually acknowledge the messages that have been delivered and ack'd
2258 * by advancing the cached remote message queue's Get value and if requested
2259 * send an IPI to the message sender's partition.
2260 */
2261static void
2262xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
2263{
2264 struct xpc_msg *msg;
2265 s64 get = initial_get + 1;
2266 int send_IPI = 0;
2267
2268
2269 while (1) {
2270
2271 while (1) {
2272 if (get == (volatile s64) ch->w_local_GP.get) {
2273 break;
2274 }
2275
2276 msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue +
2277 (get % ch->remote_nentries) * ch->msg_size);
2278
2279 if (!(msg->flags & XPC_M_DONE)) {
2280 break;
2281 }
2282
2283 msg_flags |= msg->flags;
2284 get++;
2285 }
2286
2287 if (get == initial_get) {
2288 /* nothing's changed */
2289 break;
2290 }
2291
2292 if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) !=
2293 initial_get) {
2294 /* someone else beat us to it */
2295 DBUG_ON((volatile s64) ch->local_GP->get <=
2296 initial_get);
2297 break;
2298 }
2299
2300 /* we just set the new value of local_GP->get */
2301
2302 dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
2303 "channel=%d\n", get, ch->partid, ch->number);
2304
2305 send_IPI = (msg_flags & XPC_M_INTERRUPT);
2306
2307 /*
2308 * We need to ensure that the message referenced by
2309 * local_GP->get is not XPC_M_DONE or that local_GP->get
2310 * equals w_local_GP.get, so we'll go have a look.
2311 */
2312 initial_get = get;
2313 }
2314
2315 if (send_IPI) {
2316 xpc_IPI_send_msgrequest(ch);
2317 }
2318}
2319
2320
2321/*
2322 * Acknowledge receipt of a delivered message.
2323 *
2324 * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition
2325 * that sent the message.
2326 *
2327 * This function, although called by users, does not call xpc_part_ref() to
2328 * ensure that the partition infrastructure is in place. It relies on the
2329 * fact that we called xpc_msgqueue_ref() in xpc_deliver_msg().
2330 *
2331 * Arguments:
2332 *
2333 * partid - ID of partition to which the channel is connected.
2334 * ch_number - channel # message received on.
2335 * payload - pointer to the payload area allocated via
2336 * xpc_initiate_allocate().
2337 */
2338void
2339xpc_initiate_received(partid_t partid, int ch_number, void *payload)
2340{
2341 struct xpc_partition *part = &xpc_partitions[partid];
2342 struct xpc_channel *ch;
2343 struct xpc_msg *msg = XPC_MSG_ADDRESS(payload);
2344 s64 get, msg_number = msg->number;
2345
2346
2347 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
2348 DBUG_ON(ch_number < 0 || ch_number >= part->nchannels);
2349
2350 ch = &part->channels[ch_number];
2351
2352 dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
2353 (void *) msg, msg_number, ch->partid, ch->number);
2354
2355 DBUG_ON((((u64) msg - (u64) ch->remote_msgqueue) / ch->msg_size) !=
2356 msg_number % ch->remote_nentries);
2357 DBUG_ON(msg->flags & XPC_M_DONE);
2358
2359 msg->flags |= XPC_M_DONE;
2360
2361 /*
2362 * The preceding store of msg->flags must occur before the following
2363 * load of ch->local_GP->get.
2364 */
2365 mb();
2366
2367 /*
2368 * See if this message is next in line to be acknowledged as having
2369 * been delivered.
2370 */
2371 get = ch->local_GP->get;
2372 if (get == msg_number) {
2373 xpc_acknowledge_msgs(ch, get, msg->flags);
2374 }
2375
2376 /* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg() */
2377 xpc_msgqueue_deref(ch);
2378}
2379
diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
deleted file mode 100644
index 9e0b164da9c2..000000000000
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ /dev/null
@@ -1,1431 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2007 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9
10/*
11 * Cross Partition Communication (XPC) support - standard version.
12 *
13 * XPC provides a message passing capability that crosses partition
14 * boundaries. This module is made up of two parts:
15 *
16 * partition This part detects the presence/absence of other
17 * partitions. It provides a heartbeat and monitors
18 * the heartbeats of other partitions.
19 *
20 * channel This part manages the channels and sends/receives
21 * messages across them to/from other partitions.
22 *
23 * There are a couple of additional functions residing in XP, which
24 * provide an interface to XPC for its users.
25 *
26 *
27 * Caveats:
28 *
29 * . We currently have no way to determine which nasid an IPI came
30 * from. Thus, xpc_IPI_send() does a remote AMO write followed by
31 * an IPI. The AMO indicates where data is to be pulled from, so
32 * after the IPI arrives, the remote partition checks the AMO word.
33 * The IPI can actually arrive before the AMO however, so other code
34 * must periodically check for this case. Also, remote AMO operations
35 * do not reliably time out. Thus we do a remote PIO read solely to
36 * know whether the remote partition is down and whether we should
37 * stop sending IPIs to it. This remote PIO read operation is set up
38 * in a special nofault region so SAL knows to ignore (and cleanup)
39 * any errors due to the remote AMO write, PIO read, and/or PIO
40 * write operations.
41 *
42 * If/when new hardware solves this IPI problem, we should abandon
43 * the current approach.
44 *
45 */
46
47
48#include <linux/kernel.h>
49#include <linux/module.h>
50#include <linux/init.h>
51#include <linux/sched.h>
52#include <linux/syscalls.h>
53#include <linux/cache.h>
54#include <linux/interrupt.h>
55#include <linux/delay.h>
56#include <linux/reboot.h>
57#include <linux/completion.h>
58#include <linux/kdebug.h>
59#include <asm/sn/intr.h>
60#include <asm/sn/sn_sal.h>
61#include <asm/uaccess.h>
62#include <asm/sn/xpc.h>
63
64
65/* define two XPC debug device structures to be used with dev_dbg() et al */
66
67struct device_driver xpc_dbg_name = {
68 .name = "xpc"
69};
70
71struct device xpc_part_dbg_subname = {
72 .bus_id = {0}, /* set to "part" at xpc_init() time */
73 .driver = &xpc_dbg_name
74};
75
76struct device xpc_chan_dbg_subname = {
77 .bus_id = {0}, /* set to "chan" at xpc_init() time */
78 .driver = &xpc_dbg_name
79};
80
81struct device *xpc_part = &xpc_part_dbg_subname;
82struct device *xpc_chan = &xpc_chan_dbg_subname;
83
84
85static int xpc_kdebug_ignore;
86
87
88/* systune related variables for /proc/sys directories */
89
90static int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
91static int xpc_hb_min_interval = 1;
92static int xpc_hb_max_interval = 10;
93
94static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
95static int xpc_hb_check_min_interval = 10;
96static int xpc_hb_check_max_interval = 120;
97
98int xpc_disengage_request_timelimit = XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT;
99static int xpc_disengage_request_min_timelimit = 0;
100static int xpc_disengage_request_max_timelimit = 120;
101
102static ctl_table xpc_sys_xpc_hb_dir[] = {
103 {
104 .ctl_name = CTL_UNNUMBERED,
105 .procname = "hb_interval",
106 .data = &xpc_hb_interval,
107 .maxlen = sizeof(int),
108 .mode = 0644,
109 .proc_handler = &proc_dointvec_minmax,
110 .strategy = &sysctl_intvec,
111 .extra1 = &xpc_hb_min_interval,
112 .extra2 = &xpc_hb_max_interval
113 },
114 {
115 .ctl_name = CTL_UNNUMBERED,
116 .procname = "hb_check_interval",
117 .data = &xpc_hb_check_interval,
118 .maxlen = sizeof(int),
119 .mode = 0644,
120 .proc_handler = &proc_dointvec_minmax,
121 .strategy = &sysctl_intvec,
122 .extra1 = &xpc_hb_check_min_interval,
123 .extra2 = &xpc_hb_check_max_interval
124 },
125 {}
126};
127static ctl_table xpc_sys_xpc_dir[] = {
128 {
129 .ctl_name = CTL_UNNUMBERED,
130 .procname = "hb",
131 .mode = 0555,
132 .child = xpc_sys_xpc_hb_dir
133 },
134 {
135 .ctl_name = CTL_UNNUMBERED,
136 .procname = "disengage_request_timelimit",
137 .data = &xpc_disengage_request_timelimit,
138 .maxlen = sizeof(int),
139 .mode = 0644,
140 .proc_handler = &proc_dointvec_minmax,
141 .strategy = &sysctl_intvec,
142 .extra1 = &xpc_disengage_request_min_timelimit,
143 .extra2 = &xpc_disengage_request_max_timelimit
144 },
145 {}
146};
147static ctl_table xpc_sys_dir[] = {
148 {
149 .ctl_name = CTL_UNNUMBERED,
150 .procname = "xpc",
151 .mode = 0555,
152 .child = xpc_sys_xpc_dir
153 },
154 {}
155};
156static struct ctl_table_header *xpc_sysctl;
157
158/* non-zero if any remote partition disengage request was timed out */
159int xpc_disengage_request_timedout;
160
161/* #of IRQs received */
162static atomic_t xpc_act_IRQ_rcvd;
163
164/* IRQ handler notifies this wait queue on receipt of an IRQ */
165static DECLARE_WAIT_QUEUE_HEAD(xpc_act_IRQ_wq);
166
167static unsigned long xpc_hb_check_timeout;
168
169/* notification that the xpc_hb_checker thread has exited */
170static DECLARE_COMPLETION(xpc_hb_checker_exited);
171
172/* notification that the xpc_discovery thread has exited */
173static DECLARE_COMPLETION(xpc_discovery_exited);
174
175
176static struct timer_list xpc_hb_timer;
177
178
179static void xpc_kthread_waitmsgs(struct xpc_partition *, struct xpc_channel *);
180
181
182static int xpc_system_reboot(struct notifier_block *, unsigned long, void *);
183static struct notifier_block xpc_reboot_notifier = {
184 .notifier_call = xpc_system_reboot,
185};
186
187static int xpc_system_die(struct notifier_block *, unsigned long, void *);
188static struct notifier_block xpc_die_notifier = {
189 .notifier_call = xpc_system_die,
190};
191
192
193/*
194 * Timer function to enforce the timelimit on the partition disengage request.
195 */
196static void
197xpc_timeout_partition_disengage_request(unsigned long data)
198{
199 struct xpc_partition *part = (struct xpc_partition *) data;
200
201
202 DBUG_ON(time_before(jiffies, part->disengage_request_timeout));
203
204 (void) xpc_partition_disengaged(part);
205
206 DBUG_ON(part->disengage_request_timeout != 0);
207 DBUG_ON(xpc_partition_engaged(1UL << XPC_PARTID(part)) != 0);
208}
209
210
211/*
212 * Notify the heartbeat check thread that an IRQ has been received.
213 */
214static irqreturn_t
215xpc_act_IRQ_handler(int irq, void *dev_id)
216{
217 atomic_inc(&xpc_act_IRQ_rcvd);
218 wake_up_interruptible(&xpc_act_IRQ_wq);
219 return IRQ_HANDLED;
220}
221
222
223/*
224 * Timer to produce the heartbeat. The timer structures function is
225 * already set when this is initially called. A tunable is used to
226 * specify when the next timeout should occur.
227 */
228static void
229xpc_hb_beater(unsigned long dummy)
230{
231 xpc_vars->heartbeat++;
232
233 if (time_after_eq(jiffies, xpc_hb_check_timeout)) {
234 wake_up_interruptible(&xpc_act_IRQ_wq);
235 }
236
237 xpc_hb_timer.expires = jiffies + (xpc_hb_interval * HZ);
238 add_timer(&xpc_hb_timer);
239}
240
241
242/*
243 * This thread is responsible for nearly all of the partition
244 * activation/deactivation.
245 */
246static int
247xpc_hb_checker(void *ignore)
248{
249 int last_IRQ_count = 0;
250 int new_IRQ_count;
251 int force_IRQ=0;
252
253
254 /* this thread was marked active by xpc_hb_init() */
255
256 daemonize(XPC_HB_CHECK_THREAD_NAME);
257
258 set_cpus_allowed(current, cpumask_of_cpu(XPC_HB_CHECK_CPU));
259
260 /* set our heartbeating to other partitions into motion */
261 xpc_hb_check_timeout = jiffies + (xpc_hb_check_interval * HZ);
262 xpc_hb_beater(0);
263
264 while (!(volatile int) xpc_exiting) {
265
266 dev_dbg(xpc_part, "woke up with %d ticks rem; %d IRQs have "
267 "been received\n",
268 (int) (xpc_hb_check_timeout - jiffies),
269 atomic_read(&xpc_act_IRQ_rcvd) - last_IRQ_count);
270
271
272 /* checking of remote heartbeats is skewed by IRQ handling */
273 if (time_after_eq(jiffies, xpc_hb_check_timeout)) {
274 dev_dbg(xpc_part, "checking remote heartbeats\n");
275 xpc_check_remote_hb();
276
277 /*
278 * We need to periodically recheck to ensure no
279 * IPI/AMO pairs have been missed. That check
280 * must always reset xpc_hb_check_timeout.
281 */
282 force_IRQ = 1;
283 }
284
285
286 /* check for outstanding IRQs */
287 new_IRQ_count = atomic_read(&xpc_act_IRQ_rcvd);
288 if (last_IRQ_count < new_IRQ_count || force_IRQ != 0) {
289 force_IRQ = 0;
290
291 dev_dbg(xpc_part, "found an IRQ to process; will be "
292 "resetting xpc_hb_check_timeout\n");
293
294 last_IRQ_count += xpc_identify_act_IRQ_sender();
295 if (last_IRQ_count < new_IRQ_count) {
296 /* retry once to help avoid missing AMO */
297 (void) xpc_identify_act_IRQ_sender();
298 }
299 last_IRQ_count = new_IRQ_count;
300
301 xpc_hb_check_timeout = jiffies +
302 (xpc_hb_check_interval * HZ);
303 }
304
305 /* wait for IRQ or timeout */
306 (void) wait_event_interruptible(xpc_act_IRQ_wq,
307 (last_IRQ_count < atomic_read(&xpc_act_IRQ_rcvd) ||
308 time_after_eq(jiffies, xpc_hb_check_timeout) ||
309 (volatile int) xpc_exiting));
310 }
311
312 dev_dbg(xpc_part, "heartbeat checker is exiting\n");
313
314
315 /* mark this thread as having exited */
316 complete(&xpc_hb_checker_exited);
317 return 0;
318}
319
320
321/*
322 * This thread will attempt to discover other partitions to activate
323 * based on info provided by SAL. This new thread is short lived and
324 * will exit once discovery is complete.
325 */
326static int
327xpc_initiate_discovery(void *ignore)
328{
329 daemonize(XPC_DISCOVERY_THREAD_NAME);
330
331 xpc_discovery();
332
333 dev_dbg(xpc_part, "discovery thread is exiting\n");
334
335 /* mark this thread as having exited */
336 complete(&xpc_discovery_exited);
337 return 0;
338}
339
340
341/*
342 * Establish first contact with the remote partititon. This involves pulling
343 * the XPC per partition variables from the remote partition and waiting for
344 * the remote partition to pull ours.
345 */
346static enum xpc_retval
347xpc_make_first_contact(struct xpc_partition *part)
348{
349 enum xpc_retval ret;
350
351
352 while ((ret = xpc_pull_remote_vars_part(part)) != xpcSuccess) {
353 if (ret != xpcRetry) {
354 XPC_DEACTIVATE_PARTITION(part, ret);
355 return ret;
356 }
357
358 dev_dbg(xpc_chan, "waiting to make first contact with "
359 "partition %d\n", XPC_PARTID(part));
360
361 /* wait a 1/4 of a second or so */
362 (void) msleep_interruptible(250);
363
364 if (part->act_state == XPC_P_DEACTIVATING) {
365 return part->reason;
366 }
367 }
368
369 return xpc_mark_partition_active(part);
370}
371
372
373/*
374 * The first kthread assigned to a newly activated partition is the one
375 * created by XPC HB with which it calls xpc_partition_up(). XPC hangs on to
376 * that kthread until the partition is brought down, at which time that kthread
377 * returns back to XPC HB. (The return of that kthread will signify to XPC HB
378 * that XPC has dismantled all communication infrastructure for the associated
379 * partition.) This kthread becomes the channel manager for that partition.
380 *
381 * Each active partition has a channel manager, who, besides connecting and
382 * disconnecting channels, will ensure that each of the partition's connected
383 * channels has the required number of assigned kthreads to get the work done.
384 */
385static void
386xpc_channel_mgr(struct xpc_partition *part)
387{
388 while (part->act_state != XPC_P_DEACTIVATING ||
389 atomic_read(&part->nchannels_active) > 0 ||
390 !xpc_partition_disengaged(part)) {
391
392 xpc_process_channel_activity(part);
393
394
395 /*
396 * Wait until we've been requested to activate kthreads or
397 * all of the channel's message queues have been torn down or
398 * a signal is pending.
399 *
400 * The channel_mgr_requests is set to 1 after being awakened,
401 * This is done to prevent the channel mgr from making one pass
402 * through the loop for each request, since he will
403 * be servicing all the requests in one pass. The reason it's
404 * set to 1 instead of 0 is so that other kthreads will know
405 * that the channel mgr is running and won't bother trying to
406 * wake him up.
407 */
408 atomic_dec(&part->channel_mgr_requests);
409 (void) wait_event_interruptible(part->channel_mgr_wq,
410 (atomic_read(&part->channel_mgr_requests) > 0 ||
411 (volatile u64) part->local_IPI_amo != 0 ||
412 ((volatile u8) part->act_state ==
413 XPC_P_DEACTIVATING &&
414 atomic_read(&part->nchannels_active) == 0 &&
415 xpc_partition_disengaged(part))));
416 atomic_set(&part->channel_mgr_requests, 1);
417
418 // >>> Does it need to wakeup periodically as well? In case we
419 // >>> miscalculated the #of kthreads to wakeup or create?
420 }
421}
422
423
424/*
425 * When XPC HB determines that a partition has come up, it will create a new
426 * kthread and that kthread will call this function to attempt to set up the
427 * basic infrastructure used for Cross Partition Communication with the newly
428 * upped partition.
429 *
430 * The kthread that was created by XPC HB and which setup the XPC
431 * infrastructure will remain assigned to the partition until the partition
432 * goes down. At which time the kthread will teardown the XPC infrastructure
433 * and then exit.
434 *
435 * XPC HB will put the remote partition's XPC per partition specific variables
436 * physical address into xpc_partitions[partid].remote_vars_part_pa prior to
437 * calling xpc_partition_up().
438 */
439static void
440xpc_partition_up(struct xpc_partition *part)
441{
442 DBUG_ON(part->channels != NULL);
443
444 dev_dbg(xpc_chan, "activating partition %d\n", XPC_PARTID(part));
445
446 if (xpc_setup_infrastructure(part) != xpcSuccess) {
447 return;
448 }
449
450 /*
451 * The kthread that XPC HB called us with will become the
452 * channel manager for this partition. It will not return
453 * back to XPC HB until the partition's XPC infrastructure
454 * has been dismantled.
455 */
456
457 (void) xpc_part_ref(part); /* this will always succeed */
458
459 if (xpc_make_first_contact(part) == xpcSuccess) {
460 xpc_channel_mgr(part);
461 }
462
463 xpc_part_deref(part);
464
465 xpc_teardown_infrastructure(part);
466}
467
468
469static int
470xpc_activating(void *__partid)
471{
472 partid_t partid = (u64) __partid;
473 struct xpc_partition *part = &xpc_partitions[partid];
474 unsigned long irq_flags;
475 struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
476 int ret;
477
478
479 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
480
481 spin_lock_irqsave(&part->act_lock, irq_flags);
482
483 if (part->act_state == XPC_P_DEACTIVATING) {
484 part->act_state = XPC_P_INACTIVE;
485 spin_unlock_irqrestore(&part->act_lock, irq_flags);
486 part->remote_rp_pa = 0;
487 return 0;
488 }
489
490 /* indicate the thread is activating */
491 DBUG_ON(part->act_state != XPC_P_ACTIVATION_REQ);
492 part->act_state = XPC_P_ACTIVATING;
493
494 XPC_SET_REASON(part, 0, 0);
495 spin_unlock_irqrestore(&part->act_lock, irq_flags);
496
497 dev_dbg(xpc_part, "bringing partition %d up\n", partid);
498
499 daemonize("xpc%02d", partid);
500
501 /*
502 * This thread needs to run at a realtime priority to prevent a
503 * significant performance degradation.
504 */
505 ret = sched_setscheduler(current, SCHED_FIFO, &param);
506 if (ret != 0) {
507 dev_warn(xpc_part, "unable to set pid %d to a realtime "
508 "priority, ret=%d\n", current->pid, ret);
509 }
510
511 /* allow this thread and its children to run on any CPU */
512 set_cpus_allowed(current, CPU_MASK_ALL);
513
514 /*
515 * Register the remote partition's AMOs with SAL so it can handle
516 * and cleanup errors within that address range should the remote
517 * partition go down. We don't unregister this range because it is
518 * difficult to tell when outstanding writes to the remote partition
519 * are finished and thus when it is safe to unregister. This should
520 * not result in wasted space in the SAL xp_addr_region table because
521 * we should get the same page for remote_amos_page_pa after module
522 * reloads and system reboots.
523 */
524 if (sn_register_xp_addr_region(part->remote_amos_page_pa,
525 PAGE_SIZE, 1) < 0) {
526 dev_warn(xpc_part, "xpc_partition_up(%d) failed to register "
527 "xp_addr region\n", partid);
528
529 spin_lock_irqsave(&part->act_lock, irq_flags);
530 part->act_state = XPC_P_INACTIVE;
531 XPC_SET_REASON(part, xpcPhysAddrRegFailed, __LINE__);
532 spin_unlock_irqrestore(&part->act_lock, irq_flags);
533 part->remote_rp_pa = 0;
534 return 0;
535 }
536
537 xpc_allow_hb(partid, xpc_vars);
538 xpc_IPI_send_activated(part);
539
540
541 /*
542 * xpc_partition_up() holds this thread and marks this partition as
543 * XPC_P_ACTIVE by calling xpc_hb_mark_active().
544 */
545 (void) xpc_partition_up(part);
546
547 xpc_disallow_hb(partid, xpc_vars);
548 xpc_mark_partition_inactive(part);
549
550 if (part->reason == xpcReactivating) {
551 /* interrupting ourselves results in activating partition */
552 xpc_IPI_send_reactivate(part);
553 }
554
555 return 0;
556}
557
558
559void
560xpc_activate_partition(struct xpc_partition *part)
561{
562 partid_t partid = XPC_PARTID(part);
563 unsigned long irq_flags;
564 pid_t pid;
565
566
567 spin_lock_irqsave(&part->act_lock, irq_flags);
568
569 DBUG_ON(part->act_state != XPC_P_INACTIVE);
570
571 part->act_state = XPC_P_ACTIVATION_REQ;
572 XPC_SET_REASON(part, xpcCloneKThread, __LINE__);
573
574 spin_unlock_irqrestore(&part->act_lock, irq_flags);
575
576 pid = kernel_thread(xpc_activating, (void *) ((u64) partid), 0);
577
578 if (unlikely(pid <= 0)) {
579 spin_lock_irqsave(&part->act_lock, irq_flags);
580 part->act_state = XPC_P_INACTIVE;
581 XPC_SET_REASON(part, xpcCloneKThreadFailed, __LINE__);
582 spin_unlock_irqrestore(&part->act_lock, irq_flags);
583 }
584}
585
586
587/*
588 * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
589 * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
590 * than one partition, we use an AMO_t structure per partition to indicate
591 * whether a partition has sent an IPI or not. >>> If it has, then wake up the
592 * associated kthread to handle it.
593 *
594 * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IPIs sent by XPC
595 * running on other partitions.
596 *
597 * Noteworthy Arguments:
598 *
599 * irq - Interrupt ReQuest number. NOT USED.
600 *
601 * dev_id - partid of IPI's potential sender.
602 */
603irqreturn_t
604xpc_notify_IRQ_handler(int irq, void *dev_id)
605{
606 partid_t partid = (partid_t) (u64) dev_id;
607 struct xpc_partition *part = &xpc_partitions[partid];
608
609
610 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
611
612 if (xpc_part_ref(part)) {
613 xpc_check_for_channel_activity(part);
614
615 xpc_part_deref(part);
616 }
617 return IRQ_HANDLED;
618}
619
620
621/*
622 * Check to see if xpc_notify_IRQ_handler() dropped any IPIs on the floor
623 * because the write to their associated IPI amo completed after the IRQ/IPI
624 * was received.
625 */
626void
627xpc_dropped_IPI_check(struct xpc_partition *part)
628{
629 if (xpc_part_ref(part)) {
630 xpc_check_for_channel_activity(part);
631
632 part->dropped_IPI_timer.expires = jiffies +
633 XPC_P_DROPPED_IPI_WAIT;
634 add_timer(&part->dropped_IPI_timer);
635 xpc_part_deref(part);
636 }
637}
638
639
640void
641xpc_activate_kthreads(struct xpc_channel *ch, int needed)
642{
643 int idle = atomic_read(&ch->kthreads_idle);
644 int assigned = atomic_read(&ch->kthreads_assigned);
645 int wakeup;
646
647
648 DBUG_ON(needed <= 0);
649
650 if (idle > 0) {
651 wakeup = (needed > idle) ? idle : needed;
652 needed -= wakeup;
653
654 dev_dbg(xpc_chan, "wakeup %d idle kthreads, partid=%d, "
655 "channel=%d\n", wakeup, ch->partid, ch->number);
656
657 /* only wakeup the requested number of kthreads */
658 wake_up_nr(&ch->idle_wq, wakeup);
659 }
660
661 if (needed <= 0) {
662 return;
663 }
664
665 if (needed + assigned > ch->kthreads_assigned_limit) {
666 needed = ch->kthreads_assigned_limit - assigned;
667 // >>>should never be less than 0
668 if (needed <= 0) {
669 return;
670 }
671 }
672
673 dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n",
674 needed, ch->partid, ch->number);
675
676 xpc_create_kthreads(ch, needed, 0);
677}
678
679
680/*
681 * This function is where XPC's kthreads wait for messages to deliver.
682 */
683static void
684xpc_kthread_waitmsgs(struct xpc_partition *part, struct xpc_channel *ch)
685{
686 do {
687 /* deliver messages to their intended recipients */
688
689 while ((volatile s64) ch->w_local_GP.get <
690 (volatile s64) ch->w_remote_GP.put &&
691 !((volatile u32) ch->flags &
692 XPC_C_DISCONNECTING)) {
693 xpc_deliver_msg(ch);
694 }
695
696 if (atomic_inc_return(&ch->kthreads_idle) >
697 ch->kthreads_idle_limit) {
698 /* too many idle kthreads on this channel */
699 atomic_dec(&ch->kthreads_idle);
700 break;
701 }
702
703 dev_dbg(xpc_chan, "idle kthread calling "
704 "wait_event_interruptible_exclusive()\n");
705
706 (void) wait_event_interruptible_exclusive(ch->idle_wq,
707 ((volatile s64) ch->w_local_GP.get <
708 (volatile s64) ch->w_remote_GP.put ||
709 ((volatile u32) ch->flags &
710 XPC_C_DISCONNECTING)));
711
712 atomic_dec(&ch->kthreads_idle);
713
714 } while (!((volatile u32) ch->flags & XPC_C_DISCONNECTING));
715}
716
717
718static int
719xpc_daemonize_kthread(void *args)
720{
721 partid_t partid = XPC_UNPACK_ARG1(args);
722 u16 ch_number = XPC_UNPACK_ARG2(args);
723 struct xpc_partition *part = &xpc_partitions[partid];
724 struct xpc_channel *ch;
725 int n_needed;
726 unsigned long irq_flags;
727
728
729 daemonize("xpc%02dc%d", partid, ch_number);
730
731 dev_dbg(xpc_chan, "kthread starting, partid=%d, channel=%d\n",
732 partid, ch_number);
733
734 ch = &part->channels[ch_number];
735
736 if (!(ch->flags & XPC_C_DISCONNECTING)) {
737
738 /* let registerer know that connection has been established */
739
740 spin_lock_irqsave(&ch->lock, irq_flags);
741 if (!(ch->flags & XPC_C_CONNECTEDCALLOUT)) {
742 ch->flags |= XPC_C_CONNECTEDCALLOUT;
743 spin_unlock_irqrestore(&ch->lock, irq_flags);
744
745 xpc_connected_callout(ch);
746
747 spin_lock_irqsave(&ch->lock, irq_flags);
748 ch->flags |= XPC_C_CONNECTEDCALLOUT_MADE;
749 spin_unlock_irqrestore(&ch->lock, irq_flags);
750
751 /*
752 * It is possible that while the callout was being
753 * made that the remote partition sent some messages.
754 * If that is the case, we may need to activate
755 * additional kthreads to help deliver them. We only
756 * need one less than total #of messages to deliver.
757 */
758 n_needed = ch->w_remote_GP.put - ch->w_local_GP.get - 1;
759 if (n_needed > 0 &&
760 !(ch->flags & XPC_C_DISCONNECTING)) {
761 xpc_activate_kthreads(ch, n_needed);
762 }
763 } else {
764 spin_unlock_irqrestore(&ch->lock, irq_flags);
765 }
766
767 xpc_kthread_waitmsgs(part, ch);
768 }
769
770 /* let registerer know that connection is disconnecting */
771
772 spin_lock_irqsave(&ch->lock, irq_flags);
773 if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
774 !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
775 ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
776 spin_unlock_irqrestore(&ch->lock, irq_flags);
777
778 xpc_disconnect_callout(ch, xpcDisconnecting);
779
780 spin_lock_irqsave(&ch->lock, irq_flags);
781 ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
782 }
783 spin_unlock_irqrestore(&ch->lock, irq_flags);
784
785 if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
786 if (atomic_dec_return(&part->nchannels_engaged) == 0) {
787 xpc_mark_partition_disengaged(part);
788 xpc_IPI_send_disengage(part);
789 }
790 }
791
792 xpc_msgqueue_deref(ch);
793
794 dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
795 partid, ch_number);
796
797 xpc_part_deref(part);
798 return 0;
799}
800
801
802/*
803 * For each partition that XPC has established communications with, there is
804 * a minimum of one kernel thread assigned to perform any operation that
805 * may potentially sleep or block (basically the callouts to the asynchronous
806 * functions registered via xpc_connect()).
807 *
808 * Additional kthreads are created and destroyed by XPC as the workload
809 * demands.
810 *
811 * A kthread is assigned to one of the active channels that exists for a given
812 * partition.
813 */
814void
815xpc_create_kthreads(struct xpc_channel *ch, int needed,
816 int ignore_disconnecting)
817{
818 unsigned long irq_flags;
819 pid_t pid;
820 u64 args = XPC_PACK_ARGS(ch->partid, ch->number);
821 struct xpc_partition *part = &xpc_partitions[ch->partid];
822
823
824 while (needed-- > 0) {
825
826 /*
827 * The following is done on behalf of the newly created
828 * kthread. That kthread is responsible for doing the
829 * counterpart to the following before it exits.
830 */
831 if (ignore_disconnecting) {
832 if (!atomic_inc_not_zero(&ch->kthreads_assigned)) {
833 /* kthreads assigned had gone to zero */
834 BUG_ON(!(ch->flags &
835 XPC_C_DISCONNECTINGCALLOUT_MADE));
836 break;
837 }
838
839 } else if (ch->flags & XPC_C_DISCONNECTING) {
840 break;
841
842 } else if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
843 if (atomic_inc_return(&part->nchannels_engaged) == 1)
844 xpc_mark_partition_engaged(part);
845 }
846 (void) xpc_part_ref(part);
847 xpc_msgqueue_ref(ch);
848
849 pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
850 if (pid < 0) {
851 /* the fork failed */
852
853 /*
854 * NOTE: if (ignore_disconnecting &&
855 * !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) is true,
856 * then we'll deadlock if all other kthreads assigned
857 * to this channel are blocked in the channel's
858 * registerer, because the only thing that will unblock
859 * them is the xpcDisconnecting callout that this
860 * failed kernel_thread would have made.
861 */
862
863 if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
864 atomic_dec_return(&part->nchannels_engaged) == 0) {
865 xpc_mark_partition_disengaged(part);
866 xpc_IPI_send_disengage(part);
867 }
868 xpc_msgqueue_deref(ch);
869 xpc_part_deref(part);
870
871 if (atomic_read(&ch->kthreads_assigned) <
872 ch->kthreads_idle_limit) {
873 /*
874 * Flag this as an error only if we have an
875 * insufficient #of kthreads for the channel
876 * to function.
877 */
878 spin_lock_irqsave(&ch->lock, irq_flags);
879 XPC_DISCONNECT_CHANNEL(ch, xpcLackOfResources,
880 &irq_flags);
881 spin_unlock_irqrestore(&ch->lock, irq_flags);
882 }
883 break;
884 }
885
886 ch->kthreads_created++; // >>> temporary debug only!!!
887 }
888}
889
890
891void
892xpc_disconnect_wait(int ch_number)
893{
894 unsigned long irq_flags;
895 partid_t partid;
896 struct xpc_partition *part;
897 struct xpc_channel *ch;
898 int wakeup_channel_mgr;
899
900
901 /* now wait for all callouts to the caller's function to cease */
902 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
903 part = &xpc_partitions[partid];
904
905 if (!xpc_part_ref(part)) {
906 continue;
907 }
908
909 ch = &part->channels[ch_number];
910
911 if (!(ch->flags & XPC_C_WDISCONNECT)) {
912 xpc_part_deref(part);
913 continue;
914 }
915
916 wait_for_completion(&ch->wdisconnect_wait);
917
918 spin_lock_irqsave(&ch->lock, irq_flags);
919 DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED));
920 wakeup_channel_mgr = 0;
921
922 if (ch->delayed_IPI_flags) {
923 if (part->act_state != XPC_P_DEACTIVATING) {
924 spin_lock(&part->IPI_lock);
925 XPC_SET_IPI_FLAGS(part->local_IPI_amo,
926 ch->number, ch->delayed_IPI_flags);
927 spin_unlock(&part->IPI_lock);
928 wakeup_channel_mgr = 1;
929 }
930 ch->delayed_IPI_flags = 0;
931 }
932
933 ch->flags &= ~XPC_C_WDISCONNECT;
934 spin_unlock_irqrestore(&ch->lock, irq_flags);
935
936 if (wakeup_channel_mgr) {
937 xpc_wakeup_channel_mgr(part);
938 }
939
940 xpc_part_deref(part);
941 }
942}
943
944
945static void
946xpc_do_exit(enum xpc_retval reason)
947{
948 partid_t partid;
949 int active_part_count, printed_waiting_msg = 0;
950 struct xpc_partition *part;
951 unsigned long printmsg_time, disengage_request_timeout = 0;
952
953
954 /* a 'rmmod XPC' and a 'reboot' cannot both end up here together */
955 DBUG_ON(xpc_exiting == 1);
956
957 /*
958 * Let the heartbeat checker thread and the discovery thread
959 * (if one is running) know that they should exit. Also wake up
960 * the heartbeat checker thread in case it's sleeping.
961 */
962 xpc_exiting = 1;
963 wake_up_interruptible(&xpc_act_IRQ_wq);
964
965 /* ignore all incoming interrupts */
966 free_irq(SGI_XPC_ACTIVATE, NULL);
967
968 /* wait for the discovery thread to exit */
969 wait_for_completion(&xpc_discovery_exited);
970
971 /* wait for the heartbeat checker thread to exit */
972 wait_for_completion(&xpc_hb_checker_exited);
973
974
975 /* sleep for a 1/3 of a second or so */
976 (void) msleep_interruptible(300);
977
978
979 /* wait for all partitions to become inactive */
980
981 printmsg_time = jiffies + (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
982 xpc_disengage_request_timedout = 0;
983
984 do {
985 active_part_count = 0;
986
987 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
988 part = &xpc_partitions[partid];
989
990 if (xpc_partition_disengaged(part) &&
991 part->act_state == XPC_P_INACTIVE) {
992 continue;
993 }
994
995 active_part_count++;
996
997 XPC_DEACTIVATE_PARTITION(part, reason);
998
999 if (part->disengage_request_timeout >
1000 disengage_request_timeout) {
1001 disengage_request_timeout =
1002 part->disengage_request_timeout;
1003 }
1004 }
1005
1006 if (xpc_partition_engaged(-1UL)) {
1007 if (time_after(jiffies, printmsg_time)) {
1008 dev_info(xpc_part, "waiting for remote "
1009 "partitions to disengage, timeout in "
1010 "%ld seconds\n",
1011 (disengage_request_timeout - jiffies)
1012 / HZ);
1013 printmsg_time = jiffies +
1014 (XPC_DISENGAGE_PRINTMSG_INTERVAL * HZ);
1015 printed_waiting_msg = 1;
1016 }
1017
1018 } else if (active_part_count > 0) {
1019 if (printed_waiting_msg) {
1020 dev_info(xpc_part, "waiting for local partition"
1021 " to disengage\n");
1022 printed_waiting_msg = 0;
1023 }
1024
1025 } else {
1026 if (!xpc_disengage_request_timedout) {
1027 dev_info(xpc_part, "all partitions have "
1028 "disengaged\n");
1029 }
1030 break;
1031 }
1032
1033 /* sleep for a 1/3 of a second or so */
1034 (void) msleep_interruptible(300);
1035
1036 } while (1);
1037
1038 DBUG_ON(xpc_partition_engaged(-1UL));
1039
1040
1041 /* indicate to others that our reserved page is uninitialized */
1042 xpc_rsvd_page->vars_pa = 0;
1043
1044 /* now it's time to eliminate our heartbeat */
1045 del_timer_sync(&xpc_hb_timer);
1046 DBUG_ON(xpc_vars->heartbeating_to_mask != 0);
1047
1048 if (reason == xpcUnloading) {
1049 /* take ourselves off of the reboot_notifier_list */
1050 (void) unregister_reboot_notifier(&xpc_reboot_notifier);
1051
1052 /* take ourselves off of the die_notifier list */
1053 (void) unregister_die_notifier(&xpc_die_notifier);
1054 }
1055
1056 /* close down protections for IPI operations */
1057 xpc_restrict_IPI_ops();
1058
1059
1060 /* clear the interface to XPC's functions */
1061 xpc_clear_interface();
1062
1063 if (xpc_sysctl) {
1064 unregister_sysctl_table(xpc_sysctl);
1065 }
1066
1067 kfree(xpc_remote_copy_buffer_base);
1068}
1069
1070
1071/*
1072 * This function is called when the system is being rebooted.
1073 */
1074static int
1075xpc_system_reboot(struct notifier_block *nb, unsigned long event, void *unused)
1076{
1077 enum xpc_retval reason;
1078
1079
1080 switch (event) {
1081 case SYS_RESTART:
1082 reason = xpcSystemReboot;
1083 break;
1084 case SYS_HALT:
1085 reason = xpcSystemHalt;
1086 break;
1087 case SYS_POWER_OFF:
1088 reason = xpcSystemPoweroff;
1089 break;
1090 default:
1091 reason = xpcSystemGoingDown;
1092 }
1093
1094 xpc_do_exit(reason);
1095 return NOTIFY_DONE;
1096}
1097
1098
1099/*
1100 * Notify other partitions to disengage from all references to our memory.
1101 */
1102static void
1103xpc_die_disengage(void)
1104{
1105 struct xpc_partition *part;
1106 partid_t partid;
1107 unsigned long engaged;
1108 long time, printmsg_time, disengage_request_timeout;
1109
1110
1111 /* keep xpc_hb_checker thread from doing anything (just in case) */
1112 xpc_exiting = 1;
1113
1114 xpc_vars->heartbeating_to_mask = 0; /* indicate we're deactivated */
1115
1116 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
1117 part = &xpc_partitions[partid];
1118
1119 if (!XPC_SUPPORTS_DISENGAGE_REQUEST(part->
1120 remote_vars_version)) {
1121
1122 /* just in case it was left set by an earlier XPC */
1123 xpc_clear_partition_engaged(1UL << partid);
1124 continue;
1125 }
1126
1127 if (xpc_partition_engaged(1UL << partid) ||
1128 part->act_state != XPC_P_INACTIVE) {
1129 xpc_request_partition_disengage(part);
1130 xpc_mark_partition_disengaged(part);
1131 xpc_IPI_send_disengage(part);
1132 }
1133 }
1134
1135 time = rtc_time();
1136 printmsg_time = time +
1137 (XPC_DISENGAGE_PRINTMSG_INTERVAL * sn_rtc_cycles_per_second);
1138 disengage_request_timeout = time +
1139 (xpc_disengage_request_timelimit * sn_rtc_cycles_per_second);
1140
1141 /* wait for all other partitions to disengage from us */
1142
1143 while (1) {
1144 engaged = xpc_partition_engaged(-1UL);
1145 if (!engaged) {
1146 dev_info(xpc_part, "all partitions have disengaged\n");
1147 break;
1148 }
1149
1150 time = rtc_time();
1151 if (time >= disengage_request_timeout) {
1152 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
1153 if (engaged & (1UL << partid)) {
1154 dev_info(xpc_part, "disengage from "
1155 "remote partition %d timed "
1156 "out\n", partid);
1157 }
1158 }
1159 break;
1160 }
1161
1162 if (time >= printmsg_time) {
1163 dev_info(xpc_part, "waiting for remote partitions to "
1164 "disengage, timeout in %ld seconds\n",
1165 (disengage_request_timeout - time) /
1166 sn_rtc_cycles_per_second);
1167 printmsg_time = time +
1168 (XPC_DISENGAGE_PRINTMSG_INTERVAL *
1169 sn_rtc_cycles_per_second);
1170 }
1171 }
1172}
1173
1174
1175/*
1176 * This function is called when the system is being restarted or halted due
1177 * to some sort of system failure. If this is the case we need to notify the
1178 * other partitions to disengage from all references to our memory.
1179 * This function can also be called when our heartbeater could be offlined
1180 * for a time. In this case we need to notify other partitions to not worry
1181 * about the lack of a heartbeat.
1182 */
1183static int
1184xpc_system_die(struct notifier_block *nb, unsigned long event, void *unused)
1185{
1186 switch (event) {
1187 case DIE_MACHINE_RESTART:
1188 case DIE_MACHINE_HALT:
1189 xpc_die_disengage();
1190 break;
1191
1192 case DIE_KDEBUG_ENTER:
1193 /* Should lack of heartbeat be ignored by other partitions? */
1194 if (!xpc_kdebug_ignore) {
1195 break;
1196 }
1197 /* fall through */
1198 case DIE_MCA_MONARCH_ENTER:
1199 case DIE_INIT_MONARCH_ENTER:
1200 xpc_vars->heartbeat++;
1201 xpc_vars->heartbeat_offline = 1;
1202 break;
1203
1204 case DIE_KDEBUG_LEAVE:
1205 /* Is lack of heartbeat being ignored by other partitions? */
1206 if (!xpc_kdebug_ignore) {
1207 break;
1208 }
1209 /* fall through */
1210 case DIE_MCA_MONARCH_LEAVE:
1211 case DIE_INIT_MONARCH_LEAVE:
1212 xpc_vars->heartbeat++;
1213 xpc_vars->heartbeat_offline = 0;
1214 break;
1215 }
1216
1217 return NOTIFY_DONE;
1218}
1219
1220
1221int __init
1222xpc_init(void)
1223{
1224 int ret;
1225 partid_t partid;
1226 struct xpc_partition *part;
1227 pid_t pid;
1228 size_t buf_size;
1229
1230
1231 if (!ia64_platform_is("sn2")) {
1232 return -ENODEV;
1233 }
1234
1235
1236 buf_size = max(XPC_RP_VARS_SIZE,
1237 XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES);
1238 xpc_remote_copy_buffer = xpc_kmalloc_cacheline_aligned(buf_size,
1239 GFP_KERNEL, &xpc_remote_copy_buffer_base);
1240 if (xpc_remote_copy_buffer == NULL)
1241 return -ENOMEM;
1242
1243 snprintf(xpc_part->bus_id, BUS_ID_SIZE, "part");
1244 snprintf(xpc_chan->bus_id, BUS_ID_SIZE, "chan");
1245
1246 xpc_sysctl = register_sysctl_table(xpc_sys_dir);
1247
1248 /*
1249 * The first few fields of each entry of xpc_partitions[] need to
1250 * be initialized now so that calls to xpc_connect() and
1251 * xpc_disconnect() can be made prior to the activation of any remote
1252 * partition. NOTE THAT NONE OF THE OTHER FIELDS BELONGING TO THESE
1253 * ENTRIES ARE MEANINGFUL UNTIL AFTER AN ENTRY'S CORRESPONDING
1254 * PARTITION HAS BEEN ACTIVATED.
1255 */
1256 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
1257 part = &xpc_partitions[partid];
1258
1259 DBUG_ON((u64) part != L1_CACHE_ALIGN((u64) part));
1260
1261 part->act_IRQ_rcvd = 0;
1262 spin_lock_init(&part->act_lock);
1263 part->act_state = XPC_P_INACTIVE;
1264 XPC_SET_REASON(part, 0, 0);
1265
1266 init_timer(&part->disengage_request_timer);
1267 part->disengage_request_timer.function =
1268 xpc_timeout_partition_disengage_request;
1269 part->disengage_request_timer.data = (unsigned long) part;
1270
1271 part->setup_state = XPC_P_UNSET;
1272 init_waitqueue_head(&part->teardown_wq);
1273 atomic_set(&part->references, 0);
1274 }
1275
1276 /*
1277 * Open up protections for IPI operations (and AMO operations on
1278 * Shub 1.1 systems).
1279 */
1280 xpc_allow_IPI_ops();
1281
1282 /*
1283 * Interrupts being processed will increment this atomic variable and
1284 * awaken the heartbeat thread which will process the interrupts.
1285 */
1286 atomic_set(&xpc_act_IRQ_rcvd, 0);
1287
1288 /*
1289 * This is safe to do before the xpc_hb_checker thread has started
1290 * because the handler releases a wait queue. If an interrupt is
1291 * received before the thread is waiting, it will not go to sleep,
1292 * but rather immediately process the interrupt.
1293 */
1294 ret = request_irq(SGI_XPC_ACTIVATE, xpc_act_IRQ_handler, 0,
1295 "xpc hb", NULL);
1296 if (ret != 0) {
1297 dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
1298 "errno=%d\n", -ret);
1299
1300 xpc_restrict_IPI_ops();
1301
1302 if (xpc_sysctl) {
1303 unregister_sysctl_table(xpc_sysctl);
1304 }
1305
1306 kfree(xpc_remote_copy_buffer_base);
1307 return -EBUSY;
1308 }
1309
1310 /*
1311 * Fill the partition reserved page with the information needed by
1312 * other partitions to discover we are alive and establish initial
1313 * communications.
1314 */
1315 xpc_rsvd_page = xpc_rsvd_page_init();
1316 if (xpc_rsvd_page == NULL) {
1317 dev_err(xpc_part, "could not setup our reserved page\n");
1318
1319 free_irq(SGI_XPC_ACTIVATE, NULL);
1320 xpc_restrict_IPI_ops();
1321
1322 if (xpc_sysctl) {
1323 unregister_sysctl_table(xpc_sysctl);
1324 }
1325
1326 kfree(xpc_remote_copy_buffer_base);
1327 return -EBUSY;
1328 }
1329
1330
1331 /* add ourselves to the reboot_notifier_list */
1332 ret = register_reboot_notifier(&xpc_reboot_notifier);
1333 if (ret != 0) {
1334 dev_warn(xpc_part, "can't register reboot notifier\n");
1335 }
1336
1337 /* add ourselves to the die_notifier list */
1338 ret = register_die_notifier(&xpc_die_notifier);
1339 if (ret != 0) {
1340 dev_warn(xpc_part, "can't register die notifier\n");
1341 }
1342
1343 init_timer(&xpc_hb_timer);
1344 xpc_hb_timer.function = xpc_hb_beater;
1345
1346 /*
1347 * The real work-horse behind xpc. This processes incoming
1348 * interrupts and monitors remote heartbeats.
1349 */
1350 pid = kernel_thread(xpc_hb_checker, NULL, 0);
1351 if (pid < 0) {
1352 dev_err(xpc_part, "failed while forking hb check thread\n");
1353
1354 /* indicate to others that our reserved page is uninitialized */
1355 xpc_rsvd_page->vars_pa = 0;
1356
1357 /* take ourselves off of the reboot_notifier_list */
1358 (void) unregister_reboot_notifier(&xpc_reboot_notifier);
1359
1360 /* take ourselves off of the die_notifier list */
1361 (void) unregister_die_notifier(&xpc_die_notifier);
1362
1363 del_timer_sync(&xpc_hb_timer);
1364 free_irq(SGI_XPC_ACTIVATE, NULL);
1365 xpc_restrict_IPI_ops();
1366
1367 if (xpc_sysctl) {
1368 unregister_sysctl_table(xpc_sysctl);
1369 }
1370
1371 kfree(xpc_remote_copy_buffer_base);
1372 return -EBUSY;
1373 }
1374
1375
1376 /*
1377 * Startup a thread that will attempt to discover other partitions to
1378 * activate based on info provided by SAL. This new thread is short
1379 * lived and will exit once discovery is complete.
1380 */
1381 pid = kernel_thread(xpc_initiate_discovery, NULL, 0);
1382 if (pid < 0) {
1383 dev_err(xpc_part, "failed while forking discovery thread\n");
1384
1385 /* mark this new thread as a non-starter */
1386 complete(&xpc_discovery_exited);
1387
1388 xpc_do_exit(xpcUnloading);
1389 return -EBUSY;
1390 }
1391
1392
1393 /* set the interface to point at XPC's functions */
1394 xpc_set_interface(xpc_initiate_connect, xpc_initiate_disconnect,
1395 xpc_initiate_allocate, xpc_initiate_send,
1396 xpc_initiate_send_notify, xpc_initiate_received,
1397 xpc_initiate_partid_to_nasids);
1398
1399 return 0;
1400}
1401module_init(xpc_init);
1402
1403
1404void __exit
1405xpc_exit(void)
1406{
1407 xpc_do_exit(xpcUnloading);
1408}
1409module_exit(xpc_exit);
1410
1411
1412MODULE_AUTHOR("Silicon Graphics, Inc.");
1413MODULE_DESCRIPTION("Cross Partition Communication (XPC) support");
1414MODULE_LICENSE("GPL");
1415
1416module_param(xpc_hb_interval, int, 0);
1417MODULE_PARM_DESC(xpc_hb_interval, "Number of seconds between "
1418 "heartbeat increments.");
1419
1420module_param(xpc_hb_check_interval, int, 0);
1421MODULE_PARM_DESC(xpc_hb_check_interval, "Number of seconds between "
1422 "heartbeat checks.");
1423
1424module_param(xpc_disengage_request_timelimit, int, 0);
1425MODULE_PARM_DESC(xpc_disengage_request_timelimit, "Number of seconds to wait "
1426 "for disengage request to complete.");
1427
1428module_param(xpc_kdebug_ignore, int, 0);
1429MODULE_PARM_DESC(xpc_kdebug_ignore, "Should lack of heartbeat be ignored by "
1430 "other partitions when dropping into kdebug.");
1431
diff --git a/arch/ia64/sn/kernel/xpc_partition.c b/arch/ia64/sn/kernel/xpc_partition.c
deleted file mode 100644
index 9e97c2684832..000000000000
--- a/arch/ia64/sn/kernel/xpc_partition.c
+++ /dev/null
@@ -1,1239 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9
10/*
11 * Cross Partition Communication (XPC) partition support.
12 *
13 * This is the part of XPC that detects the presence/absence of
14 * other partitions. It provides a heartbeat and monitors the
15 * heartbeats of other partitions.
16 *
17 */
18
19
20#include <linux/kernel.h>
21#include <linux/sysctl.h>
22#include <linux/cache.h>
23#include <linux/mmzone.h>
24#include <linux/nodemask.h>
25#include <asm/uncached.h>
26#include <asm/sn/bte.h>
27#include <asm/sn/intr.h>
28#include <asm/sn/sn_sal.h>
29#include <asm/sn/nodepda.h>
30#include <asm/sn/addrs.h>
31#include <asm/sn/xpc.h>
32
33
34/* XPC is exiting flag */
35int xpc_exiting;
36
37
38/* SH_IPI_ACCESS shub register value on startup */
39static u64 xpc_sh1_IPI_access;
40static u64 xpc_sh2_IPI_access0;
41static u64 xpc_sh2_IPI_access1;
42static u64 xpc_sh2_IPI_access2;
43static u64 xpc_sh2_IPI_access3;
44
45
46/* original protection values for each node */
47u64 xpc_prot_vec[MAX_NUMNODES];
48
49
50/* this partition's reserved page pointers */
51struct xpc_rsvd_page *xpc_rsvd_page;
52static u64 *xpc_part_nasids;
53static u64 *xpc_mach_nasids;
54struct xpc_vars *xpc_vars;
55struct xpc_vars_part *xpc_vars_part;
56
57static int xp_nasid_mask_bytes; /* actual size in bytes of nasid mask */
58static int xp_nasid_mask_words; /* actual size in words of nasid mask */
59
60
61/*
62 * For performance reasons, each entry of xpc_partitions[] is cacheline
63 * aligned. And xpc_partitions[] is padded with an additional entry at the
64 * end so that the last legitimate entry doesn't share its cacheline with
65 * another variable.
66 */
67struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
68
69
70/*
71 * Generic buffer used to store a local copy of portions of a remote
72 * partition's reserved page (either its header and part_nasids mask,
73 * or its vars).
74 */
75char *xpc_remote_copy_buffer;
76void *xpc_remote_copy_buffer_base;
77
78
79/*
80 * Guarantee that the kmalloc'd memory is cacheline aligned.
81 */
82void *
83xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
84{
85 /* see if kmalloc will give us cachline aligned memory by default */
86 *base = kmalloc(size, flags);
87 if (*base == NULL) {
88 return NULL;
89 }
90 if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) {
91 return *base;
92 }
93 kfree(*base);
94
95 /* nope, we'll have to do it ourselves */
96 *base = kmalloc(size + L1_CACHE_BYTES, flags);
97 if (*base == NULL) {
98 return NULL;
99 }
100 return (void *) L1_CACHE_ALIGN((u64) *base);
101}
102
103
104/*
105 * Given a nasid, get the physical address of the partition's reserved page
106 * for that nasid. This function returns 0 on any error.
107 */
108static u64
109xpc_get_rsvd_page_pa(int nasid)
110{
111 bte_result_t bte_res;
112 s64 status;
113 u64 cookie = 0;
114 u64 rp_pa = nasid; /* seed with nasid */
115 u64 len = 0;
116 u64 buf = buf;
117 u64 buf_len = 0;
118 void *buf_base = NULL;
119
120
121 while (1) {
122
123 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
124 &len);
125
126 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
127 "0x%016lx, address=0x%016lx, len=0x%016lx\n",
128 status, cookie, rp_pa, len);
129
130 if (status != SALRET_MORE_PASSES) {
131 break;
132 }
133
134 if (L1_CACHE_ALIGN(len) > buf_len) {
135 kfree(buf_base);
136 buf_len = L1_CACHE_ALIGN(len);
137 buf = (u64) xpc_kmalloc_cacheline_aligned(buf_len,
138 GFP_KERNEL, &buf_base);
139 if (buf_base == NULL) {
140 dev_err(xpc_part, "unable to kmalloc "
141 "len=0x%016lx\n", buf_len);
142 status = SALRET_ERROR;
143 break;
144 }
145 }
146
147 bte_res = xp_bte_copy(rp_pa, buf, buf_len,
148 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
149 if (bte_res != BTE_SUCCESS) {
150 dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
151 status = SALRET_ERROR;
152 break;
153 }
154 }
155
156 kfree(buf_base);
157
158 if (status != SALRET_OK) {
159 rp_pa = 0;
160 }
161 dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
162 return rp_pa;
163}
164
165
166/*
167 * Fill the partition reserved page with the information needed by
168 * other partitions to discover we are alive and establish initial
169 * communications.
170 */
171struct xpc_rsvd_page *
172xpc_rsvd_page_init(void)
173{
174 struct xpc_rsvd_page *rp;
175 AMO_t *amos_page;
176 u64 rp_pa, nasid_array = 0;
177 int i, ret;
178
179
180 /* get the local reserved page's address */
181
182 preempt_disable();
183 rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
184 preempt_enable();
185 if (rp_pa == 0) {
186 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
187 return NULL;
188 }
189 rp = (struct xpc_rsvd_page *) __va(rp_pa);
190
191 if (rp->partid != sn_partition_id) {
192 dev_err(xpc_part, "the reserved page's partid of %d should be "
193 "%d\n", rp->partid, sn_partition_id);
194 return NULL;
195 }
196
197 rp->version = XPC_RP_VERSION;
198
199 /* establish the actual sizes of the nasid masks */
200 if (rp->SAL_version == 1) {
201 /* SAL_version 1 didn't set the nasids_size field */
202 rp->nasids_size = 128;
203 }
204 xp_nasid_mask_bytes = rp->nasids_size;
205 xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
206
207 /* setup the pointers to the various items in the reserved page */
208 xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
209 xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
210 xpc_vars = XPC_RP_VARS(rp);
211 xpc_vars_part = XPC_RP_VARS_PART(rp);
212
213 /*
214 * Before clearing xpc_vars, see if a page of AMOs had been previously
215 * allocated. If not we'll need to allocate one and set permissions
216 * so that cross-partition AMOs are allowed.
217 *
218 * The allocated AMO page needs MCA reporting to remain disabled after
219 * XPC has unloaded. To make this work, we keep a copy of the pointer
220 * to this page (i.e., amos_page) in the struct xpc_vars structure,
221 * which is pointed to by the reserved page, and re-use that saved copy
222 * on subsequent loads of XPC. This AMO page is never freed, and its
223 * memory protections are never restricted.
224 */
225 if ((amos_page = xpc_vars->amos_page) == NULL) {
226 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
227 if (amos_page == NULL) {
228 dev_err(xpc_part, "can't allocate page of AMOs\n");
229 return NULL;
230 }
231
232 /*
233 * Open up AMO-R/W to cpu. This is done for Shub 1.1 systems
234 * when xpc_allow_IPI_ops() is called via xpc_hb_init().
235 */
236 if (!enable_shub_wars_1_1()) {
237 ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
238 PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
239 &nasid_array);
240 if (ret != 0) {
241 dev_err(xpc_part, "can't change memory "
242 "protections\n");
243 uncached_free_page(__IA64_UNCACHED_OFFSET |
244 TO_PHYS((u64) amos_page));
245 return NULL;
246 }
247 }
248 } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
249 /*
250 * EFI's XPBOOT can also set amos_page in the reserved page,
251 * but it happens to leave it as an uncached physical address
252 * and we need it to be an uncached virtual, so we'll have to
253 * convert it.
254 */
255 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
256 dev_err(xpc_part, "previously used amos_page address "
257 "is bad = 0x%p\n", (void *) amos_page);
258 return NULL;
259 }
260 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
261 }
262
263 /* clear xpc_vars */
264 memset(xpc_vars, 0, sizeof(struct xpc_vars));
265
266 xpc_vars->version = XPC_V_VERSION;
267 xpc_vars->act_nasid = cpuid_to_nasid(0);
268 xpc_vars->act_phys_cpuid = cpu_physical_id(0);
269 xpc_vars->vars_part_pa = __pa(xpc_vars_part);
270 xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
271 xpc_vars->amos_page = amos_page; /* save for next load of XPC */
272
273
274 /* clear xpc_vars_part */
275 memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
276 XP_MAX_PARTITIONS);
277
278 /* initialize the activate IRQ related AMO variables */
279 for (i = 0; i < xp_nasid_mask_words; i++) {
280 (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
281 }
282
283 /* initialize the engaged remote partitions related AMO variables */
284 (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
285 (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
286
287 /* timestamp of when reserved page was setup by XPC */
288 rp->stamp = CURRENT_TIME;
289
290 /*
291 * This signifies to the remote partition that our reserved
292 * page is initialized.
293 */
294 rp->vars_pa = __pa(xpc_vars);
295
296 return rp;
297}
298
299
300/*
301 * Change protections to allow IPI operations (and AMO operations on
302 * Shub 1.1 systems).
303 */
304void
305xpc_allow_IPI_ops(void)
306{
307 int node;
308 int nasid;
309
310
311 // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
312
313 if (is_shub2()) {
314 xpc_sh2_IPI_access0 =
315 (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
316 xpc_sh2_IPI_access1 =
317 (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
318 xpc_sh2_IPI_access2 =
319 (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
320 xpc_sh2_IPI_access3 =
321 (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
322
323 for_each_online_node(node) {
324 nasid = cnodeid_to_nasid(node);
325 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
326 -1UL);
327 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
328 -1UL);
329 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
330 -1UL);
331 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
332 -1UL);
333 }
334
335 } else {
336 xpc_sh1_IPI_access =
337 (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
338
339 for_each_online_node(node) {
340 nasid = cnodeid_to_nasid(node);
341 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
342 -1UL);
343
344 /*
345 * Since the BIST collides with memory operations on
346 * SHUB 1.1 sn_change_memprotect() cannot be used.
347 */
348 if (enable_shub_wars_1_1()) {
349 /* open up everything */
350 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
351 GLOBAL_MMR_ADDR(nasid,
352 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
353 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
354 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
355 -1UL);
356 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
357 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
358 -1UL);
359 }
360 }
361 }
362}
363
364
365/*
366 * Restrict protections to disallow IPI operations (and AMO operations on
367 * Shub 1.1 systems).
368 */
369void
370xpc_restrict_IPI_ops(void)
371{
372 int node;
373 int nasid;
374
375
376 // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
377
378 if (is_shub2()) {
379
380 for_each_online_node(node) {
381 nasid = cnodeid_to_nasid(node);
382 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
383 xpc_sh2_IPI_access0);
384 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
385 xpc_sh2_IPI_access1);
386 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
387 xpc_sh2_IPI_access2);
388 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
389 xpc_sh2_IPI_access3);
390 }
391
392 } else {
393
394 for_each_online_node(node) {
395 nasid = cnodeid_to_nasid(node);
396 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
397 xpc_sh1_IPI_access);
398
399 if (enable_shub_wars_1_1()) {
400 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
401 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
402 xpc_prot_vec[node]);
403 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
404 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
405 xpc_prot_vec[node]);
406 }
407 }
408 }
409}
410
411
412/*
413 * At periodic intervals, scan through all active partitions and ensure
414 * their heartbeat is still active. If not, the partition is deactivated.
415 */
416void
417xpc_check_remote_hb(void)
418{
419 struct xpc_vars *remote_vars;
420 struct xpc_partition *part;
421 partid_t partid;
422 bte_result_t bres;
423
424
425 remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
426
427 for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
428
429 if (xpc_exiting) {
430 break;
431 }
432
433 if (partid == sn_partition_id) {
434 continue;
435 }
436
437 part = &xpc_partitions[partid];
438
439 if (part->act_state == XPC_P_INACTIVE ||
440 part->act_state == XPC_P_DEACTIVATING) {
441 continue;
442 }
443
444 /* pull the remote_hb cache line */
445 bres = xp_bte_copy(part->remote_vars_pa,
446 (u64) remote_vars,
447 XPC_RP_VARS_SIZE,
448 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
449 if (bres != BTE_SUCCESS) {
450 XPC_DEACTIVATE_PARTITION(part,
451 xpc_map_bte_errors(bres));
452 continue;
453 }
454
455 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
456 " = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
457 partid, remote_vars->heartbeat, part->last_heartbeat,
458 remote_vars->heartbeat_offline,
459 remote_vars->heartbeating_to_mask);
460
461 if (((remote_vars->heartbeat == part->last_heartbeat) &&
462 (remote_vars->heartbeat_offline == 0)) ||
463 !xpc_hb_allowed(sn_partition_id, remote_vars)) {
464
465 XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
466 continue;
467 }
468
469 part->last_heartbeat = remote_vars->heartbeat;
470 }
471}
472
473
474/*
475 * Get a copy of a portion of the remote partition's rsvd page.
476 *
477 * remote_rp points to a buffer that is cacheline aligned for BTE copies and
478 * is large enough to contain a copy of their reserved page header and
479 * part_nasids mask.
480 */
481static enum xpc_retval
482xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
483 struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
484{
485 int bres, i;
486
487
488 /* get the reserved page's physical address */
489
490 *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
491 if (*remote_rp_pa == 0) {
492 return xpcNoRsvdPageAddr;
493 }
494
495
496 /* pull over the reserved page header and part_nasids mask */
497 bres = xp_bte_copy(*remote_rp_pa, (u64) remote_rp,
498 XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
499 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
500 if (bres != BTE_SUCCESS) {
501 return xpc_map_bte_errors(bres);
502 }
503
504
505 if (discovered_nasids != NULL) {
506 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
507
508
509 for (i = 0; i < xp_nasid_mask_words; i++) {
510 discovered_nasids[i] |= remote_part_nasids[i];
511 }
512 }
513
514
515 /* check that the partid is for another partition */
516
517 if (remote_rp->partid < 1 ||
518 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
519 return xpcInvalidPartid;
520 }
521
522 if (remote_rp->partid == sn_partition_id) {
523 return xpcLocalPartid;
524 }
525
526
527 if (XPC_VERSION_MAJOR(remote_rp->version) !=
528 XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
529 return xpcBadVersion;
530 }
531
532 return xpcSuccess;
533}
534
535
536/*
537 * Get a copy of the remote partition's XPC variables from the reserved page.
538 *
539 * remote_vars points to a buffer that is cacheline aligned for BTE copies and
540 * assumed to be of size XPC_RP_VARS_SIZE.
541 */
542static enum xpc_retval
543xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
544{
545 int bres;
546
547
548 if (remote_vars_pa == 0) {
549 return xpcVarsNotSet;
550 }
551
552 /* pull over the cross partition variables */
553 bres = xp_bte_copy(remote_vars_pa, (u64) remote_vars, XPC_RP_VARS_SIZE,
554 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
555 if (bres != BTE_SUCCESS) {
556 return xpc_map_bte_errors(bres);
557 }
558
559 if (XPC_VERSION_MAJOR(remote_vars->version) !=
560 XPC_VERSION_MAJOR(XPC_V_VERSION)) {
561 return xpcBadVersion;
562 }
563
564 return xpcSuccess;
565}
566
567
568/*
569 * Update the remote partition's info.
570 */
571static void
572xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
573 struct timespec *remote_rp_stamp, u64 remote_rp_pa,
574 u64 remote_vars_pa, struct xpc_vars *remote_vars)
575{
576 part->remote_rp_version = remote_rp_version;
577 dev_dbg(xpc_part, " remote_rp_version = 0x%016x\n",
578 part->remote_rp_version);
579
580 part->remote_rp_stamp = *remote_rp_stamp;
581 dev_dbg(xpc_part, " remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
582 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
583
584 part->remote_rp_pa = remote_rp_pa;
585 dev_dbg(xpc_part, " remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
586
587 part->remote_vars_pa = remote_vars_pa;
588 dev_dbg(xpc_part, " remote_vars_pa = 0x%016lx\n",
589 part->remote_vars_pa);
590
591 part->last_heartbeat = remote_vars->heartbeat;
592 dev_dbg(xpc_part, " last_heartbeat = 0x%016lx\n",
593 part->last_heartbeat);
594
595 part->remote_vars_part_pa = remote_vars->vars_part_pa;
596 dev_dbg(xpc_part, " remote_vars_part_pa = 0x%016lx\n",
597 part->remote_vars_part_pa);
598
599 part->remote_act_nasid = remote_vars->act_nasid;
600 dev_dbg(xpc_part, " remote_act_nasid = 0x%x\n",
601 part->remote_act_nasid);
602
603 part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
604 dev_dbg(xpc_part, " remote_act_phys_cpuid = 0x%x\n",
605 part->remote_act_phys_cpuid);
606
607 part->remote_amos_page_pa = remote_vars->amos_page_pa;
608 dev_dbg(xpc_part, " remote_amos_page_pa = 0x%lx\n",
609 part->remote_amos_page_pa);
610
611 part->remote_vars_version = remote_vars->version;
612 dev_dbg(xpc_part, " remote_vars_version = 0x%x\n",
613 part->remote_vars_version);
614}
615
616
617/*
618 * Prior code has determined the nasid which generated an IPI. Inspect
619 * that nasid to determine if its partition needs to be activated or
620 * deactivated.
621 *
622 * A partition is consider "awaiting activation" if our partition
623 * flags indicate it is not active and it has a heartbeat. A
624 * partition is considered "awaiting deactivation" if our partition
625 * flags indicate it is active but it has no heartbeat or it is not
626 * sending its heartbeat to us.
627 *
628 * To determine the heartbeat, the remote nasid must have a properly
629 * initialized reserved page.
630 */
631static void
632xpc_identify_act_IRQ_req(int nasid)
633{
634 struct xpc_rsvd_page *remote_rp;
635 struct xpc_vars *remote_vars;
636 u64 remote_rp_pa;
637 u64 remote_vars_pa;
638 int remote_rp_version;
639 int reactivate = 0;
640 int stamp_diff;
641 struct timespec remote_rp_stamp = { 0, 0 };
642 partid_t partid;
643 struct xpc_partition *part;
644 enum xpc_retval ret;
645
646
647 /* pull over the reserved page structure */
648
649 remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
650
651 ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
652 if (ret != xpcSuccess) {
653 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
654 "which sent interrupt, reason=%d\n", nasid, ret);
655 return;
656 }
657
658 remote_vars_pa = remote_rp->vars_pa;
659 remote_rp_version = remote_rp->version;
660 if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
661 remote_rp_stamp = remote_rp->stamp;
662 }
663 partid = remote_rp->partid;
664 part = &xpc_partitions[partid];
665
666
667 /* pull over the cross partition variables */
668
669 remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
670
671 ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
672 if (ret != xpcSuccess) {
673
674 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
675 "which sent interrupt, reason=%d\n", nasid, ret);
676
677 XPC_DEACTIVATE_PARTITION(part, ret);
678 return;
679 }
680
681
682 part->act_IRQ_rcvd++;
683
684 dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
685 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
686 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
687
688 if (xpc_partition_disengaged(part) &&
689 part->act_state == XPC_P_INACTIVE) {
690
691 xpc_update_partition_info(part, remote_rp_version,
692 &remote_rp_stamp, remote_rp_pa,
693 remote_vars_pa, remote_vars);
694
695 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
696 if (xpc_partition_disengage_requested(1UL << partid)) {
697 /*
698 * Other side is waiting on us to disengage,
699 * even though we already have.
700 */
701 return;
702 }
703 } else {
704 /* other side doesn't support disengage requests */
705 xpc_clear_partition_disengage_request(1UL << partid);
706 }
707
708 xpc_activate_partition(part);
709 return;
710 }
711
712 DBUG_ON(part->remote_rp_version == 0);
713 DBUG_ON(part->remote_vars_version == 0);
714
715 if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
716 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
717 remote_vars_version));
718
719 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
720 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
721 version));
722 /* see if the other side rebooted */
723 if (part->remote_amos_page_pa ==
724 remote_vars->amos_page_pa &&
725 xpc_hb_allowed(sn_partition_id,
726 remote_vars)) {
727 /* doesn't look that way, so ignore the IPI */
728 return;
729 }
730 }
731
732 /*
733 * Other side rebooted and previous XPC didn't support the
734 * disengage request, so we don't need to do anything special.
735 */
736
737 xpc_update_partition_info(part, remote_rp_version,
738 &remote_rp_stamp, remote_rp_pa,
739 remote_vars_pa, remote_vars);
740 part->reactivate_nasid = nasid;
741 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
742 return;
743 }
744
745 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
746
747 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
748 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
749
750 /*
751 * Other side rebooted and previous XPC did support the
752 * disengage request, but the new one doesn't.
753 */
754
755 xpc_clear_partition_engaged(1UL << partid);
756 xpc_clear_partition_disengage_request(1UL << partid);
757
758 xpc_update_partition_info(part, remote_rp_version,
759 &remote_rp_stamp, remote_rp_pa,
760 remote_vars_pa, remote_vars);
761 reactivate = 1;
762
763 } else {
764 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
765
766 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
767 &remote_rp_stamp);
768 if (stamp_diff != 0) {
769 DBUG_ON(stamp_diff >= 0);
770
771 /*
772 * Other side rebooted and the previous XPC did support
773 * the disengage request, as does the new one.
774 */
775
776 DBUG_ON(xpc_partition_engaged(1UL << partid));
777 DBUG_ON(xpc_partition_disengage_requested(1UL <<
778 partid));
779
780 xpc_update_partition_info(part, remote_rp_version,
781 &remote_rp_stamp, remote_rp_pa,
782 remote_vars_pa, remote_vars);
783 reactivate = 1;
784 }
785 }
786
787 if (part->disengage_request_timeout > 0 &&
788 !xpc_partition_disengaged(part)) {
789 /* still waiting on other side to disengage from us */
790 return;
791 }
792
793 if (reactivate) {
794 part->reactivate_nasid = nasid;
795 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
796
797 } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
798 xpc_partition_disengage_requested(1UL << partid)) {
799 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
800 }
801}
802
803
804/*
805 * Loop through the activation AMO variables and process any bits
806 * which are set. Each bit indicates a nasid sending a partition
807 * activation or deactivation request.
808 *
809 * Return #of IRQs detected.
810 */
811int
812xpc_identify_act_IRQ_sender(void)
813{
814 int word, bit;
815 u64 nasid_mask;
816 u64 nasid; /* remote nasid */
817 int n_IRQs_detected = 0;
818 AMO_t *act_amos;
819
820
821 act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
822
823
824 /* scan through act AMO variable looking for non-zero entries */
825 for (word = 0; word < xp_nasid_mask_words; word++) {
826
827 if (xpc_exiting) {
828 break;
829 }
830
831 nasid_mask = xpc_IPI_receive(&act_amos[word]);
832 if (nasid_mask == 0) {
833 /* no IRQs from nasids in this variable */
834 continue;
835 }
836
837 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
838 nasid_mask);
839
840
841 /*
842 * If this nasid has been added to the machine since
843 * our partition was reset, this will retain the
844 * remote nasid in our reserved pages machine mask.
845 * This is used in the event of module reload.
846 */
847 xpc_mach_nasids[word] |= nasid_mask;
848
849
850 /* locate the nasid(s) which sent interrupts */
851
852 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
853 if (nasid_mask & (1UL << bit)) {
854 n_IRQs_detected++;
855 nasid = XPC_NASID_FROM_W_B(word, bit);
856 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
857 nasid);
858 xpc_identify_act_IRQ_req(nasid);
859 }
860 }
861 }
862 return n_IRQs_detected;
863}
864
865
866/*
867 * See if the other side has responded to a partition disengage request
868 * from us.
869 */
870int
871xpc_partition_disengaged(struct xpc_partition *part)
872{
873 partid_t partid = XPC_PARTID(part);
874 int disengaged;
875
876
877 disengaged = (xpc_partition_engaged(1UL << partid) == 0);
878 if (part->disengage_request_timeout) {
879 if (!disengaged) {
880 if (time_before(jiffies, part->disengage_request_timeout)) {
881 /* timelimit hasn't been reached yet */
882 return 0;
883 }
884
885 /*
886 * Other side hasn't responded to our disengage
887 * request in a timely fashion, so assume it's dead.
888 */
889
890 dev_info(xpc_part, "disengage from remote partition %d "
891 "timed out\n", partid);
892 xpc_disengage_request_timedout = 1;
893 xpc_clear_partition_engaged(1UL << partid);
894 disengaged = 1;
895 }
896 part->disengage_request_timeout = 0;
897
898 /* cancel the timer function, provided it's not us */
899 if (!in_interrupt()) {
900 del_singleshot_timer_sync(&part->
901 disengage_request_timer);
902 }
903
904 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
905 part->act_state != XPC_P_INACTIVE);
906 if (part->act_state != XPC_P_INACTIVE) {
907 xpc_wakeup_channel_mgr(part);
908 }
909
910 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
911 xpc_cancel_partition_disengage_request(part);
912 }
913 }
914 return disengaged;
915}
916
917
918/*
919 * Mark specified partition as active.
920 */
921enum xpc_retval
922xpc_mark_partition_active(struct xpc_partition *part)
923{
924 unsigned long irq_flags;
925 enum xpc_retval ret;
926
927
928 dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
929
930 spin_lock_irqsave(&part->act_lock, irq_flags);
931 if (part->act_state == XPC_P_ACTIVATING) {
932 part->act_state = XPC_P_ACTIVE;
933 ret = xpcSuccess;
934 } else {
935 DBUG_ON(part->reason == xpcSuccess);
936 ret = part->reason;
937 }
938 spin_unlock_irqrestore(&part->act_lock, irq_flags);
939
940 return ret;
941}
942
943
944/*
945 * Notify XPC that the partition is down.
946 */
947void
948xpc_deactivate_partition(const int line, struct xpc_partition *part,
949 enum xpc_retval reason)
950{
951 unsigned long irq_flags;
952
953
954 spin_lock_irqsave(&part->act_lock, irq_flags);
955
956 if (part->act_state == XPC_P_INACTIVE) {
957 XPC_SET_REASON(part, reason, line);
958 spin_unlock_irqrestore(&part->act_lock, irq_flags);
959 if (reason == xpcReactivating) {
960 /* we interrupt ourselves to reactivate partition */
961 xpc_IPI_send_reactivate(part);
962 }
963 return;
964 }
965 if (part->act_state == XPC_P_DEACTIVATING) {
966 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
967 reason == xpcReactivating) {
968 XPC_SET_REASON(part, reason, line);
969 }
970 spin_unlock_irqrestore(&part->act_lock, irq_flags);
971 return;
972 }
973
974 part->act_state = XPC_P_DEACTIVATING;
975 XPC_SET_REASON(part, reason, line);
976
977 spin_unlock_irqrestore(&part->act_lock, irq_flags);
978
979 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
980 xpc_request_partition_disengage(part);
981 xpc_IPI_send_disengage(part);
982
983 /* set a timelimit on the disengage request */
984 part->disengage_request_timeout = jiffies +
985 (xpc_disengage_request_timelimit * HZ);
986 part->disengage_request_timer.expires =
987 part->disengage_request_timeout;
988 add_timer(&part->disengage_request_timer);
989 }
990
991 dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
992 XPC_PARTID(part), reason);
993
994 xpc_partition_going_down(part, reason);
995}
996
997
998/*
999 * Mark specified partition as inactive.
1000 */
1001void
1002xpc_mark_partition_inactive(struct xpc_partition *part)
1003{
1004 unsigned long irq_flags;
1005
1006
1007 dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
1008 XPC_PARTID(part));
1009
1010 spin_lock_irqsave(&part->act_lock, irq_flags);
1011 part->act_state = XPC_P_INACTIVE;
1012 spin_unlock_irqrestore(&part->act_lock, irq_flags);
1013 part->remote_rp_pa = 0;
1014}
1015
1016
1017/*
1018 * SAL has provided a partition and machine mask. The partition mask
1019 * contains a bit for each even nasid in our partition. The machine
1020 * mask contains a bit for each even nasid in the entire machine.
1021 *
1022 * Using those two bit arrays, we can determine which nasids are
1023 * known in the machine. Each should also have a reserved page
1024 * initialized if they are available for partitioning.
1025 */
1026void
1027xpc_discovery(void)
1028{
1029 void *remote_rp_base;
1030 struct xpc_rsvd_page *remote_rp;
1031 struct xpc_vars *remote_vars;
1032 u64 remote_rp_pa;
1033 u64 remote_vars_pa;
1034 int region;
1035 int region_size;
1036 int max_regions;
1037 int nasid;
1038 struct xpc_rsvd_page *rp;
1039 partid_t partid;
1040 struct xpc_partition *part;
1041 u64 *discovered_nasids;
1042 enum xpc_retval ret;
1043
1044
1045 remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
1046 xp_nasid_mask_bytes,
1047 GFP_KERNEL, &remote_rp_base);
1048 if (remote_rp == NULL) {
1049 return;
1050 }
1051 remote_vars = (struct xpc_vars *) remote_rp;
1052
1053
1054 discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
1055 GFP_KERNEL);
1056 if (discovered_nasids == NULL) {
1057 kfree(remote_rp_base);
1058 return;
1059 }
1060
1061 rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
1062
1063 /*
1064 * The term 'region' in this context refers to the minimum number of
1065 * nodes that can comprise an access protection grouping. The access
1066 * protection is in regards to memory, IOI and IPI.
1067 */
1068 max_regions = 64;
1069 region_size = sn_region_size;
1070
1071 switch (region_size) {
1072 case 128:
1073 max_regions *= 2;
1074 case 64:
1075 max_regions *= 2;
1076 case 32:
1077 max_regions *= 2;
1078 region_size = 16;
1079 DBUG_ON(!is_shub2());
1080 }
1081
1082 for (region = 0; region < max_regions; region++) {
1083
1084 if ((volatile int) xpc_exiting) {
1085 break;
1086 }
1087
1088 dev_dbg(xpc_part, "searching region %d\n", region);
1089
1090 for (nasid = (region * region_size * 2);
1091 nasid < ((region + 1) * region_size * 2);
1092 nasid += 2) {
1093
1094 if ((volatile int) xpc_exiting) {
1095 break;
1096 }
1097
1098 dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1099
1100
1101 if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1102 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1103 "part of the local partition; skipping "
1104 "region\n", nasid);
1105 break;
1106 }
1107
1108 if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1109 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1110 "not on Numa-Link network at reset\n",
1111 nasid);
1112 continue;
1113 }
1114
1115 if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1116 dev_dbg(xpc_part, "Nasid %d is part of a "
1117 "partition which was previously "
1118 "discovered\n", nasid);
1119 continue;
1120 }
1121
1122
1123 /* pull over the reserved page structure */
1124
1125 ret = xpc_get_remote_rp(nasid, discovered_nasids,
1126 remote_rp, &remote_rp_pa);
1127 if (ret != xpcSuccess) {
1128 dev_dbg(xpc_part, "unable to get reserved page "
1129 "from nasid %d, reason=%d\n", nasid,
1130 ret);
1131
1132 if (ret == xpcLocalPartid) {
1133 break;
1134 }
1135 continue;
1136 }
1137
1138 remote_vars_pa = remote_rp->vars_pa;
1139
1140 partid = remote_rp->partid;
1141 part = &xpc_partitions[partid];
1142
1143
1144 /* pull over the cross partition variables */
1145
1146 ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1147 if (ret != xpcSuccess) {
1148 dev_dbg(xpc_part, "unable to get XPC variables "
1149 "from nasid %d, reason=%d\n", nasid,
1150 ret);
1151
1152 XPC_DEACTIVATE_PARTITION(part, ret);
1153 continue;
1154 }
1155
1156 if (part->act_state != XPC_P_INACTIVE) {
1157 dev_dbg(xpc_part, "partition %d on nasid %d is "
1158 "already activating\n", partid, nasid);
1159 break;
1160 }
1161
1162 /*
1163 * Register the remote partition's AMOs with SAL so it
1164 * can handle and cleanup errors within that address
1165 * range should the remote partition go down. We don't
1166 * unregister this range because it is difficult to
1167 * tell when outstanding writes to the remote partition
1168 * are finished and thus when it is thus safe to
1169 * unregister. This should not result in wasted space
1170 * in the SAL xp_addr_region table because we should
1171 * get the same page for remote_act_amos_pa after
1172 * module reloads and system reboots.
1173 */
1174 if (sn_register_xp_addr_region(
1175 remote_vars->amos_page_pa,
1176 PAGE_SIZE, 1) < 0) {
1177 dev_dbg(xpc_part, "partition %d failed to "
1178 "register xp_addr region 0x%016lx\n",
1179 partid, remote_vars->amos_page_pa);
1180
1181 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1182 __LINE__);
1183 break;
1184 }
1185
1186 /*
1187 * The remote nasid is valid and available.
1188 * Send an interrupt to that nasid to notify
1189 * it that we are ready to begin activation.
1190 */
1191 dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1192 "nasid %d, phys_cpuid 0x%x\n",
1193 remote_vars->amos_page_pa,
1194 remote_vars->act_nasid,
1195 remote_vars->act_phys_cpuid);
1196
1197 if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1198 version)) {
1199 part->remote_amos_page_pa =
1200 remote_vars->amos_page_pa;
1201 xpc_mark_partition_disengaged(part);
1202 xpc_cancel_partition_disengage_request(part);
1203 }
1204 xpc_IPI_send_activate(remote_vars);
1205 }
1206 }
1207
1208 kfree(discovered_nasids);
1209 kfree(remote_rp_base);
1210}
1211
1212
1213/*
1214 * Given a partid, get the nasids owned by that partition from the
1215 * remote partition's reserved page.
1216 */
1217enum xpc_retval
1218xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1219{
1220 struct xpc_partition *part;
1221 u64 part_nasid_pa;
1222 int bte_res;
1223
1224
1225 part = &xpc_partitions[partid];
1226 if (part->remote_rp_pa == 0) {
1227 return xpcPartitionDown;
1228 }
1229
1230 memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1231
1232 part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
1233
1234 bte_res = xp_bte_copy(part_nasid_pa, (u64) nasid_mask,
1235 xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
1236
1237 return xpc_map_bte_errors(bte_res);
1238}
1239
diff --git a/arch/ia64/sn/kernel/xpnet.c b/arch/ia64/sn/kernel/xpnet.c
deleted file mode 100644
index a5df672d8392..000000000000
--- a/arch/ia64/sn/kernel/xpnet.c
+++ /dev/null
@@ -1,718 +0,0 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1999,2001-2005 Silicon Graphics, Inc. All rights reserved.
7 */
8
9
10/*
11 * Cross Partition Network Interface (XPNET) support
12 *
13 * XPNET provides a virtual network layered on top of the Cross
14 * Partition communication layer.
15 *
16 * XPNET provides direct point-to-point and broadcast-like support
17 * for an ethernet-like device. The ethernet broadcast medium is
18 * replaced with a point-to-point message structure which passes
19 * pointers to a DMA-capable block that a remote partition should
20 * retrieve and pass to the upper level networking layer.
21 *
22 */
23
24
25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/init.h>
28#include <linux/ioport.h>
29#include <linux/netdevice.h>
30#include <linux/etherdevice.h>
31#include <linux/delay.h>
32#include <linux/ethtool.h>
33#include <linux/mii.h>
34#include <linux/smp.h>
35#include <linux/string.h>
36#include <asm/sn/bte.h>
37#include <asm/sn/io.h>
38#include <asm/sn/sn_sal.h>
39#include <asm/types.h>
40#include <asm/atomic.h>
41#include <asm/sn/xp.h>
42
43
44/*
45 * The message payload transferred by XPC.
46 *
47 * buf_pa is the physical address where the DMA should pull from.
48 *
49 * NOTE: for performance reasons, buf_pa should _ALWAYS_ begin on a
50 * cacheline boundary. To accomplish this, we record the number of
51 * bytes from the beginning of the first cacheline to the first useful
52 * byte of the skb (leadin_ignore) and the number of bytes from the
53 * last useful byte of the skb to the end of the last cacheline
54 * (tailout_ignore).
55 *
56 * size is the number of bytes to transfer which includes the skb->len
57 * (useful bytes of the senders skb) plus the leadin and tailout
58 */
59struct xpnet_message {
60 u16 version; /* Version for this message */
61 u16 embedded_bytes; /* #of bytes embedded in XPC message */
62 u32 magic; /* Special number indicating this is xpnet */
63 u64 buf_pa; /* phys address of buffer to retrieve */
64 u32 size; /* #of bytes in buffer */
65 u8 leadin_ignore; /* #of bytes to ignore at the beginning */
66 u8 tailout_ignore; /* #of bytes to ignore at the end */
67 unsigned char data; /* body of small packets */
68};
69
70/*
71 * Determine the size of our message, the cacheline aligned size,
72 * and then the number of message will request from XPC.
73 *
74 * XPC expects each message to exist in an individual cacheline.
75 */
76#define XPNET_MSG_SIZE (L1_CACHE_BYTES - XPC_MSG_PAYLOAD_OFFSET)
77#define XPNET_MSG_DATA_MAX \
78 (XPNET_MSG_SIZE - (u64)(&((struct xpnet_message *)0)->data))
79#define XPNET_MSG_ALIGNED_SIZE (L1_CACHE_ALIGN(XPNET_MSG_SIZE))
80#define XPNET_MSG_NENTRIES (PAGE_SIZE / XPNET_MSG_ALIGNED_SIZE)
81
82
83#define XPNET_MAX_KTHREADS (XPNET_MSG_NENTRIES + 1)
84#define XPNET_MAX_IDLE_KTHREADS (XPNET_MSG_NENTRIES + 1)
85
86/*
87 * Version number of XPNET implementation. XPNET can always talk to versions
88 * with same major #, and never talk to versions with a different version.
89 */
90#define _XPNET_VERSION(_major, _minor) (((_major) << 4) | (_minor))
91#define XPNET_VERSION_MAJOR(_v) ((_v) >> 4)
92#define XPNET_VERSION_MINOR(_v) ((_v) & 0xf)
93
94#define XPNET_VERSION _XPNET_VERSION(1,0) /* version 1.0 */
95#define XPNET_VERSION_EMBED _XPNET_VERSION(1,1) /* version 1.1 */
96#define XPNET_MAGIC 0x88786984 /* "XNET" */
97
98#define XPNET_VALID_MSG(_m) \
99 ((XPNET_VERSION_MAJOR(_m->version) == XPNET_VERSION_MAJOR(XPNET_VERSION)) \
100 && (msg->magic == XPNET_MAGIC))
101
102#define XPNET_DEVICE_NAME "xp0"
103
104
105/*
106 * When messages are queued with xpc_send_notify, a kmalloc'd buffer
107 * of the following type is passed as a notification cookie. When the
108 * notification function is called, we use the cookie to decide
109 * whether all outstanding message sends have completed. The skb can
110 * then be released.
111 */
112struct xpnet_pending_msg {
113 struct list_head free_list;
114 struct sk_buff *skb;
115 atomic_t use_count;
116};
117
118/* driver specific structure pointed to by the device structure */
119struct xpnet_dev_private {
120 struct net_device_stats stats;
121};
122
123struct net_device *xpnet_device;
124
125/*
126 * When we are notified of other partitions activating, we add them to
127 * our bitmask of partitions to which we broadcast.
128 */
129static u64 xpnet_broadcast_partitions;
130/* protect above */
131static DEFINE_SPINLOCK(xpnet_broadcast_lock);
132
133/*
134 * Since the Block Transfer Engine (BTE) is being used for the transfer
135 * and it relies upon cache-line size transfers, we need to reserve at
136 * least one cache-line for head and tail alignment. The BTE is
137 * limited to 8MB transfers.
138 *
139 * Testing has shown that changing MTU to greater than 64KB has no effect
140 * on TCP as the two sides negotiate a Max Segment Size that is limited
141 * to 64K. Other protocols May use packets greater than this, but for
142 * now, the default is 64KB.
143 */
144#define XPNET_MAX_MTU (0x800000UL - L1_CACHE_BYTES)
145/* 32KB has been determined to be the ideal */
146#define XPNET_DEF_MTU (0x8000UL)
147
148
149/*
150 * The partition id is encapsulated in the MAC address. The following
151 * define locates the octet the partid is in.
152 */
153#define XPNET_PARTID_OCTET 1
154#define XPNET_LICENSE_OCTET 2
155
156
157/*
158 * Define the XPNET debug device structure that is to be used with dev_dbg(),
159 * dev_err(), dev_warn(), and dev_info().
160 */
161struct device_driver xpnet_dbg_name = {
162 .name = "xpnet"
163};
164
165struct device xpnet_dbg_subname = {
166 .bus_id = {0}, /* set to "" */
167 .driver = &xpnet_dbg_name
168};
169
170struct device *xpnet = &xpnet_dbg_subname;
171
172/*
173 * Packet was recevied by XPC and forwarded to us.
174 */
175static void
176xpnet_receive(partid_t partid, int channel, struct xpnet_message *msg)
177{
178 struct sk_buff *skb;
179 bte_result_t bret;
180 struct xpnet_dev_private *priv =
181 (struct xpnet_dev_private *) xpnet_device->priv;
182
183
184 if (!XPNET_VALID_MSG(msg)) {
185 /*
186 * Packet with a different XPC version. Ignore.
187 */
188 xpc_received(partid, channel, (void *) msg);
189
190 priv->stats.rx_errors++;
191
192 return;
193 }
194 dev_dbg(xpnet, "received 0x%lx, %d, %d, %d\n", msg->buf_pa, msg->size,
195 msg->leadin_ignore, msg->tailout_ignore);
196
197
198 /* reserve an extra cache line */
199 skb = dev_alloc_skb(msg->size + L1_CACHE_BYTES);
200 if (!skb) {
201 dev_err(xpnet, "failed on dev_alloc_skb(%d)\n",
202 msg->size + L1_CACHE_BYTES);
203
204 xpc_received(partid, channel, (void *) msg);
205
206 priv->stats.rx_errors++;
207
208 return;
209 }
210
211 /*
212 * The allocated skb has some reserved space.
213 * In order to use bte_copy, we need to get the
214 * skb->data pointer moved forward.
215 */
216 skb_reserve(skb, (L1_CACHE_BYTES - ((u64)skb->data &
217 (L1_CACHE_BYTES - 1)) +
218 msg->leadin_ignore));
219
220 /*
221 * Update the tail pointer to indicate data actually
222 * transferred.
223 */
224 skb_put(skb, (msg->size - msg->leadin_ignore - msg->tailout_ignore));
225
226 /*
227 * Move the data over from the other side.
228 */
229 if ((XPNET_VERSION_MINOR(msg->version) == 1) &&
230 (msg->embedded_bytes != 0)) {
231 dev_dbg(xpnet, "copying embedded message. memcpy(0x%p, 0x%p, "
232 "%lu)\n", skb->data, &msg->data,
233 (size_t) msg->embedded_bytes);
234
235 skb_copy_to_linear_data(skb, &msg->data, (size_t)msg->embedded_bytes);
236 } else {
237 dev_dbg(xpnet, "transferring buffer to the skb->data area;\n\t"
238 "bte_copy(0x%p, 0x%p, %hu)\n", (void *)msg->buf_pa,
239 (void *)__pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)),
240 msg->size);
241
242 bret = bte_copy(msg->buf_pa,
243 __pa((u64)skb->data & ~(L1_CACHE_BYTES - 1)),
244 msg->size, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
245
246 if (bret != BTE_SUCCESS) {
247 // >>> Need better way of cleaning skb. Currently skb
248 // >>> appears in_use and we can't just call
249 // >>> dev_kfree_skb.
250 dev_err(xpnet, "bte_copy(0x%p, 0x%p, 0x%hx) returned "
251 "error=0x%x\n", (void *)msg->buf_pa,
252 (void *)__pa((u64)skb->data &
253 ~(L1_CACHE_BYTES - 1)),
254 msg->size, bret);
255
256 xpc_received(partid, channel, (void *) msg);
257
258 priv->stats.rx_errors++;
259
260 return;
261 }
262 }
263
264 dev_dbg(xpnet, "<skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
265 "skb->end=0x%p skb->len=%d\n", (void *) skb->head,
266 (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb),
267 skb->len);
268
269 skb->protocol = eth_type_trans(skb, xpnet_device);
270 skb->ip_summed = CHECKSUM_UNNECESSARY;
271
272 dev_dbg(xpnet, "passing skb to network layer\n"
273 KERN_DEBUG "\tskb->head=0x%p skb->data=0x%p skb->tail=0x%p "
274 "skb->end=0x%p skb->len=%d\n",
275 (void *)skb->head, (void *)skb->data, skb_tail_pointer(skb),
276 skb_end_pointer(skb), skb->len);
277
278
279 xpnet_device->last_rx = jiffies;
280 priv->stats.rx_packets++;
281 priv->stats.rx_bytes += skb->len + ETH_HLEN;
282
283 netif_rx_ni(skb);
284 xpc_received(partid, channel, (void *) msg);
285}
286
287
288/*
289 * This is the handler which XPC calls during any sort of change in
290 * state or message reception on a connection.
291 */
292static void
293xpnet_connection_activity(enum xpc_retval reason, partid_t partid, int channel,
294 void *data, void *key)
295{
296 long bp;
297
298
299 DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS);
300 DBUG_ON(channel != XPC_NET_CHANNEL);
301
302 switch(reason) {
303 case xpcMsgReceived: /* message received */
304 DBUG_ON(data == NULL);
305
306 xpnet_receive(partid, channel, (struct xpnet_message *) data);
307 break;
308
309 case xpcConnected: /* connection completed to a partition */
310 spin_lock_bh(&xpnet_broadcast_lock);
311 xpnet_broadcast_partitions |= 1UL << (partid -1 );
312 bp = xpnet_broadcast_partitions;
313 spin_unlock_bh(&xpnet_broadcast_lock);
314
315 netif_carrier_on(xpnet_device);
316
317 dev_dbg(xpnet, "%s connection created to partition %d; "
318 "xpnet_broadcast_partitions=0x%lx\n",
319 xpnet_device->name, partid, bp);
320 break;
321
322 default:
323 spin_lock_bh(&xpnet_broadcast_lock);
324 xpnet_broadcast_partitions &= ~(1UL << (partid -1 ));
325 bp = xpnet_broadcast_partitions;
326 spin_unlock_bh(&xpnet_broadcast_lock);
327
328 if (bp == 0) {
329 netif_carrier_off(xpnet_device);
330 }
331
332 dev_dbg(xpnet, "%s disconnected from partition %d; "
333 "xpnet_broadcast_partitions=0x%lx\n",
334 xpnet_device->name, partid, bp);
335 break;
336
337 }
338}
339
340
341static int
342xpnet_dev_open(struct net_device *dev)
343{
344 enum xpc_retval ret;
345
346
347 dev_dbg(xpnet, "calling xpc_connect(%d, 0x%p, NULL, %ld, %ld, %ld, "
348 "%ld)\n", XPC_NET_CHANNEL, xpnet_connection_activity,
349 XPNET_MSG_SIZE, XPNET_MSG_NENTRIES, XPNET_MAX_KTHREADS,
350 XPNET_MAX_IDLE_KTHREADS);
351
352 ret = xpc_connect(XPC_NET_CHANNEL, xpnet_connection_activity, NULL,
353 XPNET_MSG_SIZE, XPNET_MSG_NENTRIES,
354 XPNET_MAX_KTHREADS, XPNET_MAX_IDLE_KTHREADS);
355 if (ret != xpcSuccess) {
356 dev_err(xpnet, "ifconfig up of %s failed on XPC connect, "
357 "ret=%d\n", dev->name, ret);
358
359 return -ENOMEM;
360 }
361
362 dev_dbg(xpnet, "ifconfig up of %s; XPC connected\n", dev->name);
363
364 return 0;
365}
366
367
368static int
369xpnet_dev_stop(struct net_device *dev)
370{
371 xpc_disconnect(XPC_NET_CHANNEL);
372
373 dev_dbg(xpnet, "ifconfig down of %s; XPC disconnected\n", dev->name);
374
375 return 0;
376}
377
378
379static int
380xpnet_dev_change_mtu(struct net_device *dev, int new_mtu)
381{
382 /* 68 comes from min TCP+IP+MAC header */
383 if ((new_mtu < 68) || (new_mtu > XPNET_MAX_MTU)) {
384 dev_err(xpnet, "ifconfig %s mtu %d failed; value must be "
385 "between 68 and %ld\n", dev->name, new_mtu,
386 XPNET_MAX_MTU);
387 return -EINVAL;
388 }
389
390 dev->mtu = new_mtu;
391 dev_dbg(xpnet, "ifconfig %s mtu set to %d\n", dev->name, new_mtu);
392 return 0;
393}
394
395
396/*
397 * Required for the net_device structure.
398 */
399static int
400xpnet_dev_set_config(struct net_device *dev, struct ifmap *new_map)
401{
402 return 0;
403}
404
405
406/*
407 * Return statistics to the caller.
408 */
409static struct net_device_stats *
410xpnet_dev_get_stats(struct net_device *dev)
411{
412 struct xpnet_dev_private *priv;
413
414
415 priv = (struct xpnet_dev_private *) dev->priv;
416
417 return &priv->stats;
418}
419
420
421/*
422 * Notification that the other end has received the message and
423 * DMA'd the skb information. At this point, they are done with
424 * our side. When all recipients are done processing, we
425 * release the skb and then release our pending message structure.
426 */
427static void
428xpnet_send_completed(enum xpc_retval reason, partid_t partid, int channel,
429 void *__qm)
430{
431 struct xpnet_pending_msg *queued_msg =
432 (struct xpnet_pending_msg *) __qm;
433
434
435 DBUG_ON(queued_msg == NULL);
436
437 dev_dbg(xpnet, "message to %d notified with reason %d\n",
438 partid, reason);
439
440 if (atomic_dec_return(&queued_msg->use_count) == 0) {
441 dev_dbg(xpnet, "all acks for skb->head=-x%p\n",
442 (void *) queued_msg->skb->head);
443
444 dev_kfree_skb_any(queued_msg->skb);
445 kfree(queued_msg);
446 }
447}
448
449
450/*
451 * Network layer has formatted a packet (skb) and is ready to place it
452 * "on the wire". Prepare and send an xpnet_message to all partitions
453 * which have connected with us and are targets of this packet.
454 *
455 * MAC-NOTE: For the XPNET driver, the MAC address contains the
456 * destination partition_id. If the destination partition id word
457 * is 0xff, this packet is to broadcast to all partitions.
458 */
459static int
460xpnet_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
461{
462 struct xpnet_pending_msg *queued_msg;
463 enum xpc_retval ret;
464 struct xpnet_message *msg;
465 u64 start_addr, end_addr;
466 long dp;
467 u8 second_mac_octet;
468 partid_t dest_partid;
469 struct xpnet_dev_private *priv;
470 u16 embedded_bytes;
471
472
473 priv = (struct xpnet_dev_private *) dev->priv;
474
475
476 dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
477 "skb->end=0x%p skb->len=%d\n", (void *) skb->head,
478 (void *)skb->data, skb_tail_pointer(skb), skb_end_pointer(skb),
479 skb->len);
480
481
482 /*
483 * The xpnet_pending_msg tracks how many outstanding
484 * xpc_send_notifies are relying on this skb. When none
485 * remain, release the skb.
486 */
487 queued_msg = kmalloc(sizeof(struct xpnet_pending_msg), GFP_ATOMIC);
488 if (queued_msg == NULL) {
489 dev_warn(xpnet, "failed to kmalloc %ld bytes; dropping "
490 "packet\n", sizeof(struct xpnet_pending_msg));
491
492 priv->stats.tx_errors++;
493
494 return -ENOMEM;
495 }
496
497
498 /* get the beginning of the first cacheline and end of last */
499 start_addr = ((u64) skb->data & ~(L1_CACHE_BYTES - 1));
500 end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb));
501
502 /* calculate how many bytes to embed in the XPC message */
503 embedded_bytes = 0;
504 if (unlikely(skb->len <= XPNET_MSG_DATA_MAX)) {
505 /* skb->data does fit so embed */
506 embedded_bytes = skb->len;
507 }
508
509
510 /*
511 * Since the send occurs asynchronously, we set the count to one
512 * and begin sending. Any sends that happen to complete before
513 * we are done sending will not free the skb. We will be left
514 * with that task during exit. This also handles the case of
515 * a packet destined for a partition which is no longer up.
516 */
517 atomic_set(&queued_msg->use_count, 1);
518 queued_msg->skb = skb;
519
520
521 second_mac_octet = skb->data[XPNET_PARTID_OCTET];
522 if (second_mac_octet == 0xff) {
523 /* we are being asked to broadcast to all partitions */
524 dp = xpnet_broadcast_partitions;
525 } else if (second_mac_octet != 0) {
526 dp = xpnet_broadcast_partitions &
527 (1UL << (second_mac_octet - 1));
528 } else {
529 /* 0 is an invalid partid. Ignore */
530 dp = 0;
531 }
532 dev_dbg(xpnet, "destination Partitions mask (dp) = 0x%lx\n", dp);
533
534 /*
535 * If we wanted to allow promiscuous mode to work like an
536 * unswitched network, this would be a good point to OR in a
537 * mask of partitions which should be receiving all packets.
538 */
539
540 /*
541 * Main send loop.
542 */
543 for (dest_partid = 1; dp && dest_partid < XP_MAX_PARTITIONS;
544 dest_partid++) {
545
546
547 if (!(dp & (1UL << (dest_partid - 1)))) {
548 /* not destined for this partition */
549 continue;
550 }
551
552 /* remove this partition from the destinations mask */
553 dp &= ~(1UL << (dest_partid - 1));
554
555
556 /* found a partition to send to */
557
558 ret = xpc_allocate(dest_partid, XPC_NET_CHANNEL,
559 XPC_NOWAIT, (void **)&msg);
560 if (unlikely(ret != xpcSuccess)) {
561 continue;
562 }
563
564 msg->embedded_bytes = embedded_bytes;
565 if (unlikely(embedded_bytes != 0)) {
566 msg->version = XPNET_VERSION_EMBED;
567 dev_dbg(xpnet, "calling memcpy(0x%p, 0x%p, 0x%lx)\n",
568 &msg->data, skb->data, (size_t) embedded_bytes);
569 skb_copy_from_linear_data(skb, &msg->data,
570 (size_t)embedded_bytes);
571 } else {
572 msg->version = XPNET_VERSION;
573 }
574 msg->magic = XPNET_MAGIC;
575 msg->size = end_addr - start_addr;
576 msg->leadin_ignore = (u64) skb->data - start_addr;
577 msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb);
578 msg->buf_pa = __pa(start_addr);
579
580 dev_dbg(xpnet, "sending XPC message to %d:%d\n"
581 KERN_DEBUG "msg->buf_pa=0x%lx, msg->size=%u, "
582 "msg->leadin_ignore=%u, msg->tailout_ignore=%u\n",
583 dest_partid, XPC_NET_CHANNEL, msg->buf_pa, msg->size,
584 msg->leadin_ignore, msg->tailout_ignore);
585
586
587 atomic_inc(&queued_msg->use_count);
588
589 ret = xpc_send_notify(dest_partid, XPC_NET_CHANNEL, msg,
590 xpnet_send_completed, queued_msg);
591 if (unlikely(ret != xpcSuccess)) {
592 atomic_dec(&queued_msg->use_count);
593 continue;
594 }
595
596 }
597
598 if (atomic_dec_return(&queued_msg->use_count) == 0) {
599 dev_dbg(xpnet, "no partitions to receive packet destined for "
600 "%d\n", dest_partid);
601
602
603 dev_kfree_skb(skb);
604 kfree(queued_msg);
605 }
606
607 priv->stats.tx_packets++;
608 priv->stats.tx_bytes += skb->len;
609
610 return 0;
611}
612
613
614/*
615 * Deal with transmit timeouts coming from the network layer.
616 */
617static void
618xpnet_dev_tx_timeout (struct net_device *dev)
619{
620 struct xpnet_dev_private *priv;
621
622
623 priv = (struct xpnet_dev_private *) dev->priv;
624
625 priv->stats.tx_errors++;
626 return;
627}
628
629
630static int __init
631xpnet_init(void)
632{
633 int i;
634 u32 license_num;
635 int result = -ENOMEM;
636
637
638 if (!ia64_platform_is("sn2")) {
639 return -ENODEV;
640 }
641
642 dev_info(xpnet, "registering network device %s\n", XPNET_DEVICE_NAME);
643
644 /*
645 * use ether_setup() to init the majority of our device
646 * structure and then override the necessary pieces.
647 */
648 xpnet_device = alloc_netdev(sizeof(struct xpnet_dev_private),
649 XPNET_DEVICE_NAME, ether_setup);
650 if (xpnet_device == NULL) {
651 return -ENOMEM;
652 }
653
654 netif_carrier_off(xpnet_device);
655
656 xpnet_device->mtu = XPNET_DEF_MTU;
657 xpnet_device->change_mtu = xpnet_dev_change_mtu;
658 xpnet_device->open = xpnet_dev_open;
659 xpnet_device->get_stats = xpnet_dev_get_stats;
660 xpnet_device->stop = xpnet_dev_stop;
661 xpnet_device->hard_start_xmit = xpnet_dev_hard_start_xmit;
662 xpnet_device->tx_timeout = xpnet_dev_tx_timeout;
663 xpnet_device->set_config = xpnet_dev_set_config;
664
665 /*
666 * Multicast assumes the LSB of the first octet is set for multicast
667 * MAC addresses. We chose the first octet of the MAC to be unlikely
668 * to collide with any vendor's officially issued MAC.
669 */
670 xpnet_device->dev_addr[0] = 0xfe;
671 xpnet_device->dev_addr[XPNET_PARTID_OCTET] = sn_partition_id;
672 license_num = sn_partition_serial_number_val();
673 for (i = 3; i >= 0; i--) {
674 xpnet_device->dev_addr[XPNET_LICENSE_OCTET + i] =
675 license_num & 0xff;
676 license_num = license_num >> 8;
677 }
678
679 /*
680 * ether_setup() sets this to a multicast device. We are
681 * really not supporting multicast at this time.
682 */
683 xpnet_device->flags &= ~IFF_MULTICAST;
684
685 /*
686 * No need to checksum as it is a DMA transfer. The BTE will
687 * report an error if the data is not retrievable and the
688 * packet will be dropped.
689 */
690 xpnet_device->features = NETIF_F_NO_CSUM;
691
692 result = register_netdev(xpnet_device);
693 if (result != 0) {
694 free_netdev(xpnet_device);
695 }
696
697 return result;
698}
699module_init(xpnet_init);
700
701
702static void __exit
703xpnet_exit(void)
704{
705 dev_info(xpnet, "unregistering network device %s\n",
706 xpnet_device[0].name);
707
708 unregister_netdev(xpnet_device);
709
710 free_netdev(xpnet_device);
711}
712module_exit(xpnet_exit);
713
714
715MODULE_AUTHOR("Silicon Graphics, Inc.");
716MODULE_DESCRIPTION("Cross Partition Network adapter (XPNET)");
717MODULE_LICENSE("GPL");
718
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-16 04:28:44 -0500