diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-08 13:10:11 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-08 13:10:11 -0400 |
commit | 45d7f32c7a43cbb9592886d38190e379e2eb2226 (patch) | |
tree | ea68b67b1d2127527d856248c0485f2ed7e50088 /arch/tile/kernel/smp.c | |
parent | 53bcef60633086ad73683d01a4ef9ca678484d2d (diff) | |
parent | ab11b487402f97975f3ac1eeea09c82f4431481e (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: check kmalloc() result
arch/tile: catch up on various minor cleanups.
arch/tile: avoid erroneous error return for PTRACE_POKEUSR.
tile: set ARCH_KMALLOC_MINALIGN
tile: remove homegrown L1_CACHE_ALIGN macro
arch/tile: Miscellaneous cleanup changes.
arch/tile: Split the icache flush code off to a generic <arch> header.
arch/tile: Fix bug in support for atomic64_xx() ops.
arch/tile: Shrink the tile-opcode files considerably.
arch/tile: Add driver to enable access to the user dynamic network.
arch/tile: Enable more sophisticated IRQ model for 32-bit chips.
Move list types from <linux/list.h> to <linux/types.h>.
Add wait4() back to the set of <asm-generic/unistd.h> syscalls.
Revert adding some arch-specific signal syscalls to <linux/syscalls.h>.
arch/tile: Do not use GFP_KERNEL for dma_alloc_coherent(). Feedback from fujita.tomonori@lab.ntt.co.jp.
arch/tile: core support for Tilera 32-bit chips.
Fix up the "generic" unistd.h ABI to be more useful.
Diffstat (limited to 'arch/tile/kernel/smp.c')
-rw-r--r-- | arch/tile/kernel/smp.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/arch/tile/kernel/smp.c b/arch/tile/kernel/smp.c new file mode 100644 index 00000000000..1cb5ec79de0 --- /dev/null +++ b/arch/tile/kernel/smp.c | |||
@@ -0,0 +1,256 @@ | |||
1 | /* | ||
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU General Public License | ||
6 | * as published by the Free Software Foundation, version 2. | ||
7 | * | ||
8 | * This program is distributed in the hope that it will be useful, but | ||
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | ||
11 | * NON INFRINGEMENT. See the GNU General Public License for | ||
12 | * more details. | ||
13 | * | ||
14 | * TILE SMP support routines. | ||
15 | */ | ||
16 | |||
17 | #include <linux/smp.h> | ||
18 | #include <linux/interrupt.h> | ||
19 | #include <linux/io.h> | ||
20 | #include <linux/irq.h> | ||
21 | #include <linux/module.h> | ||
22 | #include <asm/cacheflush.h> | ||
23 | |||
24 | HV_Topology smp_topology __write_once; | ||
25 | EXPORT_SYMBOL(smp_topology); | ||
26 | |||
27 | #if CHIP_HAS_IPI() | ||
28 | static unsigned long __iomem *ipi_mappings[NR_CPUS]; | ||
29 | #endif | ||
30 | |||
31 | |||
32 | /* | ||
33 | * Top-level send_IPI*() functions to send messages to other cpus. | ||
34 | */ | ||
35 | |||
36 | /* Set by smp_send_stop() to avoid recursive panics. */ | ||
37 | static int stopping_cpus; | ||
38 | |||
39 | void send_IPI_single(int cpu, int tag) | ||
40 | { | ||
41 | HV_Recipient recip = { | ||
42 | .y = cpu / smp_width, | ||
43 | .x = cpu % smp_width, | ||
44 | .state = HV_TO_BE_SENT | ||
45 | }; | ||
46 | int rc = hv_send_message(&recip, 1, (HV_VirtAddr)&tag, sizeof(tag)); | ||
47 | BUG_ON(rc <= 0); | ||
48 | } | ||
49 | |||
50 | void send_IPI_many(const struct cpumask *mask, int tag) | ||
51 | { | ||
52 | HV_Recipient recip[NR_CPUS]; | ||
53 | int cpu, sent; | ||
54 | int nrecip = 0; | ||
55 | int my_cpu = smp_processor_id(); | ||
56 | for_each_cpu(cpu, mask) { | ||
57 | HV_Recipient *r; | ||
58 | BUG_ON(cpu == my_cpu); | ||
59 | r = &recip[nrecip++]; | ||
60 | r->y = cpu / smp_width; | ||
61 | r->x = cpu % smp_width; | ||
62 | r->state = HV_TO_BE_SENT; | ||
63 | } | ||
64 | sent = 0; | ||
65 | while (sent < nrecip) { | ||
66 | int rc = hv_send_message(recip, nrecip, | ||
67 | (HV_VirtAddr)&tag, sizeof(tag)); | ||
68 | if (rc <= 0) { | ||
69 | if (!stopping_cpus) /* avoid recursive panic */ | ||
70 | panic("hv_send_message returned %d", rc); | ||
71 | break; | ||
72 | } | ||
73 | sent += rc; | ||
74 | } | ||
75 | } | ||
76 | |||
77 | void send_IPI_allbutself(int tag) | ||
78 | { | ||
79 | struct cpumask mask; | ||
80 | cpumask_copy(&mask, cpu_online_mask); | ||
81 | cpumask_clear_cpu(smp_processor_id(), &mask); | ||
82 | send_IPI_many(&mask, tag); | ||
83 | } | ||
84 | |||
85 | |||
86 | /* | ||
87 | * Provide smp_call_function_mask, but also run function locally | ||
88 | * if specified in the mask. | ||
89 | */ | ||
90 | void on_each_cpu_mask(const struct cpumask *mask, void (*func)(void *), | ||
91 | void *info, bool wait) | ||
92 | { | ||
93 | int cpu = get_cpu(); | ||
94 | smp_call_function_many(mask, func, info, wait); | ||
95 | if (cpumask_test_cpu(cpu, mask)) { | ||
96 | local_irq_disable(); | ||
97 | func(info); | ||
98 | local_irq_enable(); | ||
99 | } | ||
100 | put_cpu(); | ||
101 | } | ||
102 | |||
103 | |||
104 | /* | ||
105 | * Functions related to starting/stopping cpus. | ||
106 | */ | ||
107 | |||
108 | /* Handler to start the current cpu. */ | ||
109 | static void smp_start_cpu_interrupt(void) | ||
110 | { | ||
111 | get_irq_regs()->pc = start_cpu_function_addr; | ||
112 | } | ||
113 | |||
114 | /* Handler to stop the current cpu. */ | ||
115 | static void smp_stop_cpu_interrupt(void) | ||
116 | { | ||
117 | set_cpu_online(smp_processor_id(), 0); | ||
118 | raw_local_irq_disable_all(); | ||
119 | for (;;) | ||
120 | asm("nap"); | ||
121 | } | ||
122 | |||
123 | /* This function calls the 'stop' function on all other CPUs in the system. */ | ||
124 | void smp_send_stop(void) | ||
125 | { | ||
126 | stopping_cpus = 1; | ||
127 | send_IPI_allbutself(MSG_TAG_STOP_CPU); | ||
128 | } | ||
129 | |||
130 | |||
131 | /* | ||
132 | * Dispatch code called from hv_message_intr() for HV_MSG_TILE hv messages. | ||
133 | */ | ||
134 | void evaluate_message(int tag) | ||
135 | { | ||
136 | switch (tag) { | ||
137 | case MSG_TAG_START_CPU: /* Start up a cpu */ | ||
138 | smp_start_cpu_interrupt(); | ||
139 | break; | ||
140 | |||
141 | case MSG_TAG_STOP_CPU: /* Sent to shut down slave CPU's */ | ||
142 | smp_stop_cpu_interrupt(); | ||
143 | break; | ||
144 | |||
145 | case MSG_TAG_CALL_FUNCTION_MANY: /* Call function on cpumask */ | ||
146 | generic_smp_call_function_interrupt(); | ||
147 | break; | ||
148 | |||
149 | case MSG_TAG_CALL_FUNCTION_SINGLE: /* Call function on one other CPU */ | ||
150 | generic_smp_call_function_single_interrupt(); | ||
151 | break; | ||
152 | |||
153 | default: | ||
154 | panic("Unknown IPI message tag %d", tag); | ||
155 | break; | ||
156 | } | ||
157 | } | ||
158 | |||
159 | |||
160 | /* | ||
161 | * flush_icache_range() code uses smp_call_function(). | ||
162 | */ | ||
163 | |||
164 | struct ipi_flush { | ||
165 | unsigned long start; | ||
166 | unsigned long end; | ||
167 | }; | ||
168 | |||
169 | static void ipi_flush_icache_range(void *info) | ||
170 | { | ||
171 | struct ipi_flush *flush = (struct ipi_flush *) info; | ||
172 | __flush_icache_range(flush->start, flush->end); | ||
173 | } | ||
174 | |||
175 | void flush_icache_range(unsigned long start, unsigned long end) | ||
176 | { | ||
177 | struct ipi_flush flush = { start, end }; | ||
178 | preempt_disable(); | ||
179 | on_each_cpu(ipi_flush_icache_range, &flush, 1); | ||
180 | preempt_enable(); | ||
181 | } | ||
182 | |||
183 | |||
184 | /* Called when smp_send_reschedule() triggers IRQ_RESCHEDULE. */ | ||
185 | static irqreturn_t handle_reschedule_ipi(int irq, void *token) | ||
186 | { | ||
187 | /* | ||
188 | * Nothing to do here; when we return from interrupt, the | ||
189 | * rescheduling will occur there. But do bump the interrupt | ||
190 | * profiler count in the meantime. | ||
191 | */ | ||
192 | __get_cpu_var(irq_stat).irq_resched_count++; | ||
193 | |||
194 | return IRQ_HANDLED; | ||
195 | } | ||
196 | |||
197 | static struct irqaction resched_action = { | ||
198 | .handler = handle_reschedule_ipi, | ||
199 | .name = "resched", | ||
200 | .dev_id = handle_reschedule_ipi /* unique token */, | ||
201 | }; | ||
202 | |||
203 | void __init ipi_init(void) | ||
204 | { | ||
205 | #if CHIP_HAS_IPI() | ||
206 | int cpu; | ||
207 | /* Map IPI trigger MMIO addresses. */ | ||
208 | for_each_possible_cpu(cpu) { | ||
209 | HV_Coord tile; | ||
210 | HV_PTE pte; | ||
211 | unsigned long offset; | ||
212 | |||
213 | tile.x = cpu_x(cpu); | ||
214 | tile.y = cpu_y(cpu); | ||
215 | if (hv_get_ipi_pte(tile, 1, &pte) != 0) | ||
216 | panic("Failed to initialize IPI for cpu %d\n", cpu); | ||
217 | |||
218 | offset = hv_pte_get_pfn(pte) << PAGE_SHIFT; | ||
219 | ipi_mappings[cpu] = ioremap_prot(offset, PAGE_SIZE, pte); | ||
220 | } | ||
221 | #endif | ||
222 | |||
223 | /* Bind handle_reschedule_ipi() to IRQ_RESCHEDULE. */ | ||
224 | tile_irq_activate(IRQ_RESCHEDULE, TILE_IRQ_PERCPU); | ||
225 | BUG_ON(setup_irq(IRQ_RESCHEDULE, &resched_action)); | ||
226 | } | ||
227 | |||
228 | #if CHIP_HAS_IPI() | ||
229 | |||
230 | void smp_send_reschedule(int cpu) | ||
231 | { | ||
232 | WARN_ON(cpu_is_offline(cpu)); | ||
233 | |||
234 | /* | ||
235 | * We just want to do an MMIO store. The traditional writeq() | ||
236 | * functions aren't really correct here, since they're always | ||
237 | * directed at the PCI shim. For now, just do a raw store, | ||
238 | * casting away the __iomem attribute. | ||
239 | */ | ||
240 | ((unsigned long __force *)ipi_mappings[cpu])[IRQ_RESCHEDULE] = 0; | ||
241 | } | ||
242 | |||
243 | #else | ||
244 | |||
245 | void smp_send_reschedule(int cpu) | ||
246 | { | ||
247 | HV_Coord coord; | ||
248 | |||
249 | WARN_ON(cpu_is_offline(cpu)); | ||
250 | |||
251 | coord.y = cpu_y(cpu); | ||
252 | coord.x = cpu_x(cpu); | ||
253 | hv_trigger_ipi(coord, IRQ_RESCHEDULE); | ||
254 | } | ||
255 | |||
256 | #endif /* CHIP_HAS_IPI() */ | ||