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-rw-r--r--arch/mips/Kconfig26
-rw-r--r--arch/mips/kernel/Makefile1
-rw-r--r--arch/mips/kernel/cevt-r4k.c173
-rw-r--r--arch/mips/kernel/cevt-smtc.c321
-rw-r--r--arch/mips/kernel/cpu-probe.c10
-rw-r--r--arch/mips/kernel/genex.S4
-rw-r--r--arch/mips/kernel/smtc.c252
-rw-r--r--arch/mips/mti-malta/malta-smtc.c9
8 files changed, 523 insertions, 273 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 49896a2a1d7..c930b8ceb41 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1403,7 +1403,6 @@ config MIPS_MT_SMTC
1403 depends on CPU_MIPS32_R2 1403 depends on CPU_MIPS32_R2
1404 #depends on CPU_MIPS64_R2 # once there is hardware ... 1404 #depends on CPU_MIPS64_R2 # once there is hardware ...
1405 depends on SYS_SUPPORTS_MULTITHREADING 1405 depends on SYS_SUPPORTS_MULTITHREADING
1406 select GENERIC_CLOCKEVENTS_BROADCAST
1407 select CPU_MIPSR2_IRQ_VI 1406 select CPU_MIPSR2_IRQ_VI
1408 select CPU_MIPSR2_IRQ_EI 1407 select CPU_MIPSR2_IRQ_EI
1409 select MIPS_MT 1408 select MIPS_MT
@@ -1451,32 +1450,17 @@ config MIPS_VPE_LOADER
1451 Includes a loader for loading an elf relocatable object 1450 Includes a loader for loading an elf relocatable object
1452 onto another VPE and running it. 1451 onto another VPE and running it.
1453 1452
1454config MIPS_MT_SMTC_INSTANT_REPLAY
1455 bool "Low-latency Dispatch of Deferred SMTC IPIs"
1456 depends on MIPS_MT_SMTC && !PREEMPT
1457 default y
1458 help
1459 SMTC pseudo-interrupts between TCs are deferred and queued
1460 if the target TC is interrupt-inhibited (IXMT). In the first
1461 SMTC prototypes, these queued IPIs were serviced on return
1462 to user mode, or on entry into the kernel idle loop. The
1463 INSTANT_REPLAY option dispatches them as part of local_irq_restore()
1464 processing, which adds runtime overhead (hence the option to turn
1465 it off), but ensures that IPIs are handled promptly even under
1466 heavy I/O interrupt load.
1467
1468config MIPS_MT_SMTC_IM_BACKSTOP 1453config MIPS_MT_SMTC_IM_BACKSTOP
1469 bool "Use per-TC register bits as backstop for inhibited IM bits" 1454 bool "Use per-TC register bits as backstop for inhibited IM bits"
1470 depends on MIPS_MT_SMTC 1455 depends on MIPS_MT_SMTC
1471 default y 1456 default n
1472 help 1457 help
1473 To support multiple TC microthreads acting as "CPUs" within 1458 To support multiple TC microthreads acting as "CPUs" within
1474 a VPE, VPE-wide interrupt mask bits must be specially manipulated 1459 a VPE, VPE-wide interrupt mask bits must be specially manipulated
1475 during interrupt handling. To support legacy drivers and interrupt 1460 during interrupt handling. To support legacy drivers and interrupt
1476 controller management code, SMTC has a "backstop" to track and 1461 controller management code, SMTC has a "backstop" to track and
1477 if necessary restore the interrupt mask. This has some performance 1462 if necessary restore the interrupt mask. This has some performance
1478 impact on interrupt service overhead. Disable it only if you know 1463 impact on interrupt service overhead.
1479 what you are doing.
1480 1464
1481config MIPS_MT_SMTC_IRQAFF 1465config MIPS_MT_SMTC_IRQAFF
1482 bool "Support IRQ affinity API" 1466 bool "Support IRQ affinity API"
@@ -1486,10 +1470,8 @@ config MIPS_MT_SMTC_IRQAFF
1486 Enables SMP IRQ affinity API (/proc/irq/*/smp_affinity, etc.) 1470 Enables SMP IRQ affinity API (/proc/irq/*/smp_affinity, etc.)
1487 for SMTC Linux kernel. Requires platform support, of which 1471 for SMTC Linux kernel. Requires platform support, of which
1488 an example can be found in the MIPS kernel i8259 and Malta 1472 an example can be found in the MIPS kernel i8259 and Malta
1489 platform code. It is recommended that MIPS_MT_SMTC_INSTANT_REPLAY 1473 platform code. Adds some overhead to interrupt dispatch, and
1490 be enabled if MIPS_MT_SMTC_IRQAFF is used. Adds overhead to 1474 should be used only if you know what you are doing.
1491 interrupt dispatch, and should be used only if you know what
1492 you are doing.
1493 1475
1494config MIPS_VPE_LOADER_TOM 1476config MIPS_VPE_LOADER_TOM
1495 bool "Load VPE program into memory hidden from linux" 1477 bool "Load VPE program into memory hidden from linux"
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 706f9397479..25775cb5400 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -10,6 +10,7 @@ obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \
10 10
11obj-$(CONFIG_CEVT_BCM1480) += cevt-bcm1480.o 11obj-$(CONFIG_CEVT_BCM1480) += cevt-bcm1480.o
12obj-$(CONFIG_CEVT_R4K) += cevt-r4k.o 12obj-$(CONFIG_CEVT_R4K) += cevt-r4k.o
13obj-$(CONFIG_MIPS_MT_SMTC) += cevt-smtc.o
13obj-$(CONFIG_CEVT_DS1287) += cevt-ds1287.o 14obj-$(CONFIG_CEVT_DS1287) += cevt-ds1287.o
14obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o 15obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o
15obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o 16obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 24a2d907aa0..4a4c59f2737 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -12,6 +12,14 @@
12 12
13#include <asm/smtc_ipi.h> 13#include <asm/smtc_ipi.h>
14#include <asm/time.h> 14#include <asm/time.h>
15#include <asm/cevt-r4k.h>
16
17/*
18 * The SMTC Kernel for the 34K, 1004K, et. al. replaces several
19 * of these routines with SMTC-specific variants.
20 */
21
22#ifndef CONFIG_MIPS_MT_SMTC
15 23
16static int mips_next_event(unsigned long delta, 24static int mips_next_event(unsigned long delta,
17 struct clock_event_device *evt) 25 struct clock_event_device *evt)
@@ -19,60 +27,27 @@ static int mips_next_event(unsigned long delta,
19 unsigned int cnt; 27 unsigned int cnt;
20 int res; 28 int res;
21 29
22#ifdef CONFIG_MIPS_MT_SMTC
23 {
24 unsigned long flags, vpflags;
25 local_irq_save(flags);
26 vpflags = dvpe();
27#endif
28 cnt = read_c0_count(); 30 cnt = read_c0_count();
29 cnt += delta; 31 cnt += delta;
30 write_c0_compare(cnt); 32 write_c0_compare(cnt);
31 res = ((int)(read_c0_count() - cnt) > 0) ? -ETIME : 0; 33 res = ((int)(read_c0_count() - cnt) > 0) ? -ETIME : 0;
32#ifdef CONFIG_MIPS_MT_SMTC
33 evpe(vpflags);
34 local_irq_restore(flags);
35 }
36#endif
37 return res; 34 return res;
38} 35}
39 36
40static void mips_set_mode(enum clock_event_mode mode, 37#endif /* CONFIG_MIPS_MT_SMTC */
41 struct clock_event_device *evt) 38
39void mips_set_clock_mode(enum clock_event_mode mode,
40 struct clock_event_device *evt)
42{ 41{
43 /* Nothing to do ... */ 42 /* Nothing to do ... */
44} 43}
45 44
46static DEFINE_PER_CPU(struct clock_event_device, mips_clockevent_device); 45DEFINE_PER_CPU(struct clock_event_device, mips_clockevent_device);
47static int cp0_timer_irq_installed; 46int cp0_timer_irq_installed;
48 47
49/* 48#ifndef CONFIG_MIPS_MT_SMTC
50 * Timer ack for an R4k-compatible timer of a known frequency.
51 */
52static void c0_timer_ack(void)
53{
54 write_c0_compare(read_c0_compare());
55}
56 49
57/* 50irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
58 * Possibly handle a performance counter interrupt.
59 * Return true if the timer interrupt should not be checked
60 */
61static inline int handle_perf_irq(int r2)
62{
63 /*
64 * The performance counter overflow interrupt may be shared with the
65 * timer interrupt (cp0_perfcount_irq < 0). If it is and a
66 * performance counter has overflowed (perf_irq() == IRQ_HANDLED)
67 * and we can't reliably determine if a counter interrupt has also
68 * happened (!r2) then don't check for a timer interrupt.
69 */
70 return (cp0_perfcount_irq < 0) &&
71 perf_irq() == IRQ_HANDLED &&
72 !r2;
73}
74
75static irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
76{ 51{
77 const int r2 = cpu_has_mips_r2; 52 const int r2 = cpu_has_mips_r2;
78 struct clock_event_device *cd; 53 struct clock_event_device *cd;
@@ -93,12 +68,8 @@ static irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
93 * interrupt. Being the paranoiacs we are we check anyway. 68 * interrupt. Being the paranoiacs we are we check anyway.
94 */ 69 */
95 if (!r2 || (read_c0_cause() & (1 << 30))) { 70 if (!r2 || (read_c0_cause() & (1 << 30))) {
96 c0_timer_ack(); 71 /* Clear Count/Compare Interrupt */
97#ifdef CONFIG_MIPS_MT_SMTC 72 write_c0_compare(read_c0_compare());
98 if (cpu_data[cpu].vpe_id)
99 goto out;
100 cpu = 0;
101#endif
102 cd = &per_cpu(mips_clockevent_device, cpu); 73 cd = &per_cpu(mips_clockevent_device, cpu);
103 cd->event_handler(cd); 74 cd->event_handler(cd);
104 } 75 }
@@ -107,65 +78,16 @@ out:
107 return IRQ_HANDLED; 78 return IRQ_HANDLED;
108} 79}
109 80
110static struct irqaction c0_compare_irqaction = { 81#endif /* Not CONFIG_MIPS_MT_SMTC */
82
83struct irqaction c0_compare_irqaction = {
111 .handler = c0_compare_interrupt, 84 .handler = c0_compare_interrupt,
112#ifdef CONFIG_MIPS_MT_SMTC
113 .flags = IRQF_DISABLED,
114#else
115 .flags = IRQF_DISABLED | IRQF_PERCPU, 85 .flags = IRQF_DISABLED | IRQF_PERCPU,
116#endif
117 .name = "timer", 86 .name = "timer",
118}; 87};
119 88
120#ifdef CONFIG_MIPS_MT_SMTC
121DEFINE_PER_CPU(struct clock_event_device, smtc_dummy_clockevent_device);
122
123static void smtc_set_mode(enum clock_event_mode mode,
124 struct clock_event_device *evt)
125{
126}
127
128static void mips_broadcast(cpumask_t mask)
129{
130 unsigned int cpu;
131
132 for_each_cpu_mask(cpu, mask)
133 smtc_send_ipi(cpu, SMTC_CLOCK_TICK, 0);
134}
135
136static void setup_smtc_dummy_clockevent_device(void)
137{
138 //uint64_t mips_freq = mips_hpt_^frequency;
139 unsigned int cpu = smp_processor_id();
140 struct clock_event_device *cd;
141 89
142 cd = &per_cpu(smtc_dummy_clockevent_device, cpu); 90void mips_event_handler(struct clock_event_device *dev)
143
144 cd->name = "SMTC";
145 cd->features = CLOCK_EVT_FEAT_DUMMY;
146
147 /* Calculate the min / max delta */
148 cd->mult = 0; //div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
149 cd->shift = 0; //32;
150 cd->max_delta_ns = 0; //clockevent_delta2ns(0x7fffffff, cd);
151 cd->min_delta_ns = 0; //clockevent_delta2ns(0x30, cd);
152
153 cd->rating = 200;
154 cd->irq = 17; //-1;
155// if (cpu)
156// cd->cpumask = CPU_MASK_ALL; // cpumask_of_cpu(cpu);
157// else
158 cd->cpumask = cpumask_of_cpu(cpu);
159
160 cd->set_mode = smtc_set_mode;
161
162 cd->broadcast = mips_broadcast;
163
164 clockevents_register_device(cd);
165}
166#endif
167
168static void mips_event_handler(struct clock_event_device *dev)
169{ 91{
170} 92}
171 93
@@ -177,7 +99,23 @@ static int c0_compare_int_pending(void)
177 return (read_c0_cause() >> cp0_compare_irq) & 0x100; 99 return (read_c0_cause() >> cp0_compare_irq) & 0x100;
178} 100}
179 101
180static int c0_compare_int_usable(void) 102/*
103 * Compare interrupt can be routed and latched outside the core,
104 * so a single execution hazard barrier may not be enough to give
105 * it time to clear as seen in the Cause register. 4 time the
106 * pipeline depth seems reasonably conservative, and empirically
107 * works better in configurations with high CPU/bus clock ratios.
108 */
109
110#define compare_change_hazard() \
111 do { \
112 irq_disable_hazard(); \
113 irq_disable_hazard(); \
114 irq_disable_hazard(); \
115 irq_disable_hazard(); \
116 } while (0)
117
118int c0_compare_int_usable(void)
181{ 119{
182 unsigned int delta; 120 unsigned int delta;
183 unsigned int cnt; 121 unsigned int cnt;
@@ -187,7 +125,7 @@ static int c0_compare_int_usable(void)
187 */ 125 */
188 if (c0_compare_int_pending()) { 126 if (c0_compare_int_pending()) {
189 write_c0_compare(read_c0_count()); 127 write_c0_compare(read_c0_count());
190 irq_disable_hazard(); 128 compare_change_hazard();
191 if (c0_compare_int_pending()) 129 if (c0_compare_int_pending())
192 return 0; 130 return 0;
193 } 131 }
@@ -196,7 +134,7 @@ static int c0_compare_int_usable(void)
196 cnt = read_c0_count(); 134 cnt = read_c0_count();
197 cnt += delta; 135 cnt += delta;
198 write_c0_compare(cnt); 136 write_c0_compare(cnt);
199 irq_disable_hazard(); 137 compare_change_hazard();
200 if ((int)(read_c0_count() - cnt) < 0) 138 if ((int)(read_c0_count() - cnt) < 0)
201 break; 139 break;
202 /* increase delta if the timer was already expired */ 140 /* increase delta if the timer was already expired */
@@ -205,11 +143,12 @@ static int c0_compare_int_usable(void)
205 while ((int)(read_c0_count() - cnt) <= 0) 143 while ((int)(read_c0_count() - cnt) <= 0)
206 ; /* Wait for expiry */ 144 ; /* Wait for expiry */
207 145
146 compare_change_hazard();
208 if (!c0_compare_int_pending()) 147 if (!c0_compare_int_pending())
209 return 0; 148 return 0;
210 149
211 write_c0_compare(read_c0_count()); 150 write_c0_compare(read_c0_count());
212 irq_disable_hazard(); 151 compare_change_hazard();
213 if (c0_compare_int_pending()) 152 if (c0_compare_int_pending())
214 return 0; 153 return 0;
215 154
@@ -219,6 +158,8 @@ static int c0_compare_int_usable(void)
219 return 1; 158 return 1;
220} 159}
221 160
161#ifndef CONFIG_MIPS_MT_SMTC
162
222int __cpuinit mips_clockevent_init(void) 163int __cpuinit mips_clockevent_init(void)
223{ 164{
224 uint64_t mips_freq = mips_hpt_frequency; 165 uint64_t mips_freq = mips_hpt_frequency;
@@ -229,17 +170,6 @@ int __cpuinit mips_clockevent_init(void)
229 if (!cpu_has_counter || !mips_hpt_frequency) 170 if (!cpu_has_counter || !mips_hpt_frequency)
230 return -ENXIO; 171 return -ENXIO;
231 172
232#ifdef CONFIG_MIPS_MT_SMTC
233 setup_smtc_dummy_clockevent_device();
234
235 /*
236 * On SMTC we only register VPE0's compare interrupt as clockevent
237 * device.
238 */
239 if (cpu)
240 return 0;
241#endif
242
243 if (!c0_compare_int_usable()) 173 if (!c0_compare_int_usable())
244 return -ENXIO; 174 return -ENXIO;
245 175
@@ -265,13 +195,9 @@ int __cpuinit mips_clockevent_init(void)
265 195
266 cd->rating = 300; 196 cd->rating = 300;
267 cd->irq = irq; 197 cd->irq = irq;
268#ifdef CONFIG_MIPS_MT_SMTC
269 cd->cpumask = CPU_MASK_ALL;
270#else
271 cd->cpumask = cpumask_of_cpu(cpu); 198 cd->cpumask = cpumask_of_cpu(cpu);
272#endif
273 cd->set_next_event = mips_next_event; 199 cd->set_next_event = mips_next_event;
274 cd->set_mode = mips_set_mode; 200 cd->set_mode = mips_set_clock_mode;
275 cd->event_handler = mips_event_handler; 201 cd->event_handler = mips_event_handler;
276 202
277 clockevents_register_device(cd); 203 clockevents_register_device(cd);
@@ -281,12 +207,9 @@ int __cpuinit mips_clockevent_init(void)
281 207
282 cp0_timer_irq_installed = 1; 208 cp0_timer_irq_installed = 1;
283 209
284#ifdef CONFIG_MIPS_MT_SMTC
285#define CPUCTR_IMASKBIT (0x100 << cp0_compare_irq)
286 setup_irq_smtc(irq, &c0_compare_irqaction, CPUCTR_IMASKBIT);
287#else
288 setup_irq(irq, &c0_compare_irqaction); 210 setup_irq(irq, &c0_compare_irqaction);
289#endif
290 211
291 return 0; 212 return 0;
292} 213}
214
215#endif /* Not CONFIG_MIPS_MT_SMTC */
diff --git a/arch/mips/kernel/cevt-smtc.c b/arch/mips/kernel/cevt-smtc.c
new file mode 100644
index 00000000000..5162fe4b595
--- /dev/null
+++ b/arch/mips/kernel/cevt-smtc.c
@@ -0,0 +1,321 @@
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) 2007 MIPS Technologies, Inc.
7 * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
8 * Copyright (C) 2008 Kevin D. Kissell, Paralogos sarl
9 */
10#include <linux/clockchips.h>
11#include <linux/interrupt.h>
12#include <linux/percpu.h>
13
14#include <asm/smtc_ipi.h>
15#include <asm/time.h>
16#include <asm/cevt-r4k.h>
17
18/*
19 * Variant clock event timer support for SMTC on MIPS 34K, 1004K
20 * or other MIPS MT cores.
21 *
22 * Notes on SMTC Support:
23 *
24 * SMTC has multiple microthread TCs pretending to be Linux CPUs.
25 * But there's only one Count/Compare pair per VPE, and Compare
26 * interrupts are taken opportunisitically by available TCs
27 * bound to the VPE with the Count register. The new timer
28 * framework provides for global broadcasts, but we really
29 * want VPE-level multicasts for best behavior. So instead
30 * of invoking the high-level clock-event broadcast code,
31 * this version of SMTC support uses the historical SMTC
32 * multicast mechanisms "under the hood", appearing to the
33 * generic clock layer as if the interrupts are per-CPU.
34 *
35 * The approach taken here is to maintain a set of NR_CPUS
36 * virtual timers, and track which "CPU" needs to be alerted
37 * at each event.
38 *
39 * It's unlikely that we'll see a MIPS MT core with more than
40 * 2 VPEs, but we *know* that we won't need to handle more
41 * VPEs than we have "CPUs". So NCPUs arrays of NCPUs elements
42 * is always going to be overkill, but always going to be enough.
43 */
44
45unsigned long smtc_nexttime[NR_CPUS][NR_CPUS];
46static int smtc_nextinvpe[NR_CPUS];
47
48/*
49 * Timestamps stored are absolute values to be programmed
50 * into Count register. Valid timestamps will never be zero.
51 * If a Zero Count value is actually calculated, it is converted
52 * to be a 1, which will introduce 1 or two CPU cycles of error
53 * roughly once every four billion events, which at 1000 HZ means
54 * about once every 50 days. If that's actually a problem, one
55 * could alternate squashing 0 to 1 and to -1.
56 */
57
58#define MAKEVALID(x) (((x) == 0L) ? 1L : (x))
59#define ISVALID(x) ((x) != 0L)
60
61/*
62 * Time comparison is subtle, as it's really truncated
63 * modular arithmetic.
64 */
65
66#define IS_SOONER(a, b, reference) \
67 (((a) - (unsigned long)(reference)) < ((b) - (unsigned long)(reference)))
68
69/*
70 * CATCHUP_INCREMENT, used when the function falls behind the counter.
71 * Could be an increasing function instead of a constant;
72 */
73
74#define CATCHUP_INCREMENT 64
75
76static int mips_next_event(unsigned long delta,
77 struct clock_event_device *evt)
78{
79 unsigned long flags;
80 unsigned int mtflags;
81 unsigned long timestamp, reference, previous;
82 unsigned long nextcomp = 0L;
83 int vpe = current_cpu_data.vpe_id;
84 int cpu = smp_processor_id();
85 local_irq_save(flags);
86 mtflags = dmt();
87
88 /*
89 * Maintain the per-TC virtual timer
90 * and program the per-VPE shared Count register
91 * as appropriate here...
92 */
93 reference = (unsigned long)read_c0_count();
94 timestamp = MAKEVALID(reference + delta);
95 /*
96 * To really model the clock, we have to catch the case
97 * where the current next-in-VPE timestamp is the old
98 * timestamp for the calling CPE, but the new value is
99 * in fact later. In that case, we have to do a full
100 * scan and discover the new next-in-VPE CPU id and
101 * timestamp.
102 */
103 previous = smtc_nexttime[vpe][cpu];
104 if (cpu == smtc_nextinvpe[vpe] && ISVALID(previous)
105 && IS_SOONER(previous, timestamp, reference)) {
106 int i;
107 int soonest = cpu;
108
109 /*
110 * Update timestamp array here, so that new
111 * value gets considered along with those of
112 * other virtual CPUs on the VPE.
113 */
114 smtc_nexttime[vpe][cpu] = timestamp;
115 for_each_online_cpu(i) {
116 if (ISVALID(smtc_nexttime[vpe][i])
117 && IS_SOONER(smtc_nexttime[vpe][i],
118 smtc_nexttime[vpe][soonest], reference)) {
119 soonest = i;
120 }
121 }
122 smtc_nextinvpe[vpe] = soonest;
123 nextcomp = smtc_nexttime[vpe][soonest];
124 /*
125 * Otherwise, we don't have to process the whole array rank,
126 * we just have to see if the event horizon has gotten closer.
127 */
128 } else {
129 if (!ISVALID(smtc_nexttime[vpe][smtc_nextinvpe[vpe]]) ||
130 IS_SOONER(timestamp,
131 smtc_nexttime[vpe][smtc_nextinvpe[vpe]], reference)) {
132 smtc_nextinvpe[vpe] = cpu;
133 nextcomp = timestamp;
134 }
135 /*
136 * Since next-in-VPE may me the same as the executing
137 * virtual CPU, we update the array *after* checking
138 * its value.
139 */
140 smtc_nexttime[vpe][cpu] = timestamp;
141 }
142
143 /*
144 * It may be that, in fact, we don't need to update Compare,
145 * but if we do, we want to make sure we didn't fall into
146 * a crack just behind Count.
147 */
148 if (ISVALID(nextcomp)) {
149 write_c0_compare(nextcomp);
150 ehb();
151 /*
152 * We never return an error, we just make sure
153 * that we trigger the handlers as quickly as
154 * we can if we fell behind.
155 */
156 while ((nextcomp - (unsigned long)read_c0_count())
157 > (unsigned long)LONG_MAX) {
158 nextcomp += CATCHUP_INCREMENT;
159 write_c0_compare(nextcomp);
160 ehb();
161 }
162 }
163 emt(mtflags);
164 local_irq_restore(flags);
165 return 0;
166}
167
168
169void smtc_distribute_timer(int vpe)
170{
171 unsigned long flags;
172 unsigned int mtflags;
173 int cpu;
174 struct clock_event_device *cd;
175 unsigned long nextstamp = 0L;
176 unsigned long reference;
177
178
179repeat:
180 for_each_online_cpu(cpu) {
181 /*
182 * Find virtual CPUs within the current VPE who have
183 * unserviced timer requests whose time is now past.
184 */
185 local_irq_save(flags);
186 mtflags = dmt();
187 if (cpu_data[cpu].vpe_id == vpe &&
188 ISVALID(smtc_nexttime[vpe][cpu])) {
189 reference = (unsigned long)read_c0_count();
190 if ((smtc_nexttime[vpe][cpu] - reference)
191 > (unsigned long)LONG_MAX) {
192 smtc_nexttime[vpe][cpu] = 0L;
193 emt(mtflags);
194 local_irq_restore(flags);
195 /*
196 * We don't send IPIs to ourself.
197 */
198 if (cpu != smp_processor_id()) {
199 smtc_send_ipi(cpu, SMTC_CLOCK_TICK, 0);
200 } else {
201 cd = &per_cpu(mips_clockevent_device, cpu);
202 cd->event_handler(cd);
203 }
204 } else {
205 /* Local to VPE but Valid Time not yet reached. */
206 if (!ISVALID(nextstamp) ||
207 IS_SOONER(smtc_nexttime[vpe][cpu], nextstamp,
208 reference)) {
209 smtc_nextinvpe[vpe] = cpu;
210 nextstamp = smtc_nexttime[vpe][cpu];
211 }
212 emt(mtflags);
213 local_irq_restore(flags);
214 }
215 } else {
216 emt(mtflags);
217 local_irq_restore(flags);
218
219 }
220 }
221 /* Reprogram for interrupt at next soonest timestamp for VPE */
222 if (ISVALID(nextstamp)) {
223 write_c0_compare(nextstamp);
224 ehb();
225 if ((nextstamp - (unsigned long)read_c0_count())
226 > (unsigned long)LONG_MAX)
227 goto repeat;
228 }
229}
230
231
232irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
233{
234 int cpu = smp_processor_id();
235
236 /* If we're running SMTC, we've got MIPS MT and therefore MIPS32R2 */
237 handle_perf_irq(1);
238
239 if (read_c0_cause() & (1 << 30)) {
240 /* Clear Count/Compare Interrupt */
241 write_c0_compare(read_c0_compare());
242 smtc_distribute_timer(cpu_data[cpu].vpe_id);
243 }
244 return IRQ_HANDLED;
245}
246
247
248int __cpuinit mips_clockevent_init(void)
249{
250 uint64_t mips_freq = mips_hpt_frequency;
251 unsigned int cpu = smp_processor_id();
252 struct clock_event_device *cd;
253 unsigned int irq;
254 int i;
255 int j;
256
257 if (!cpu_has_counter || !mips_hpt_frequency)
258 return -ENXIO;
259 if (cpu == 0) {
260 for (i = 0; i < num_possible_cpus(); i++) {
261 smtc_nextinvpe[i] = 0;
262 for (j = 0; j < num_possible_cpus(); j++)
263 smtc_nexttime[i][j] = 0L;
264 }
265 /*
266 * SMTC also can't have the usablility test
267 * run by secondary TCs once Compare is in use.
268 */
269 if (!c0_compare_int_usable())
270 return -ENXIO;
271 }
272
273 /*
274 * With vectored interrupts things are getting platform specific.
275 * get_c0_compare_int is a hook to allow a platform to return the
276 * interrupt number of it's liking.
277 */
278 irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
279 if (get_c0_compare_int)
280 irq = get_c0_compare_int();
281
282 cd = &per_cpu(mips_clockevent_device, cpu);
283
284 cd->name = "MIPS";
285 cd->features = CLOCK_EVT_FEAT_ONESHOT;
286
287 /* Calculate the min / max delta */
288 cd->mult = div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
289 cd->shift = 32;
290 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
291 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
292
293 cd->rating = 300;
294 cd->irq = irq;
295 cd->cpumask = cpumask_of_cpu(cpu);
296 cd->set_next_event = mips_next_event;
297 cd->set_mode = mips_set_clock_mode;
298 cd->event_handler = mips_event_handler;
299
300 clockevents_register_device(cd);
301
302 /*
303 * On SMTC we only want to do the data structure
304 * initialization and IRQ setup once.
305 */
306 if (cpu)
307 return 0;
308 /*
309 * And we need the hwmask associated with the c0_compare
310 * vector to be initialized.
311 */
312 irq_hwmask[irq] = (0x100 << cp0_compare_irq);
313 if (cp0_timer_irq_installed)
314 return 0;
315
316 cp0_timer_irq_installed = 1;
317
318 setup_irq(irq, &c0_compare_irqaction);
319
320 return 0;
321}
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 11c92dc5379..e621fda8ab3 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -54,14 +54,18 @@ extern void r4k_wait(void);
54 * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes 54 * interrupt is requested" restriction in the MIPS32/MIPS64 architecture makes
55 * using this version a gamble. 55 * using this version a gamble.
56 */ 56 */
57static void r4k_wait_irqoff(void) 57void r4k_wait_irqoff(void)
58{ 58{
59 local_irq_disable(); 59 local_irq_disable();
60 if (!need_resched()) 60 if (!need_resched())
61 __asm__(" .set mips3 \n" 61 __asm__(" .set push \n"
62 " .set mips3 \n"
62 " wait \n" 63 " wait \n"
63 " .set mips0 \n"); 64 " .set pop \n");
64 local_irq_enable(); 65 local_irq_enable();
66 __asm__(" .globl __pastwait \n"
67 "__pastwait: \n");
68 return;
65} 69}
66 70
67/* 71/*
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index f886dd7f708..01dcbe38fa0 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -282,8 +282,8 @@ NESTED(except_vec_vi_handler, 0, sp)
282 and t0, a0, t1 282 and t0, a0, t1
283#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP 283#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
284 mfc0 t2, CP0_TCCONTEXT 284 mfc0 t2, CP0_TCCONTEXT
285 or t0, t0, t2 285 or t2, t0, t2
286 mtc0 t0, CP0_TCCONTEXT 286 mtc0 t2, CP0_TCCONTEXT
287#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */ 287#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
288 xor t1, t1, t0 288 xor t1, t1, t0
289 mtc0 t1, CP0_STATUS 289 mtc0 t1, CP0_STATUS
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index 39b491b9ad8..897fb2b4751 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -1,4 +1,21 @@
1/* Copyright (C) 2004 Mips Technologies, Inc */ 1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License
4 * as published by the Free Software Foundation; either version 2
5 * of the License, or (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
15 *
16 * Copyright (C) 2004 Mips Technologies, Inc
17 * Copyright (C) 2008 Kevin D. Kissell
18 */
2 19
3#include <linux/clockchips.h> 20#include <linux/clockchips.h>
4#include <linux/kernel.h> 21#include <linux/kernel.h>
@@ -21,7 +38,6 @@
21#include <asm/time.h> 38#include <asm/time.h>
22#include <asm/addrspace.h> 39#include <asm/addrspace.h>
23#include <asm/smtc.h> 40#include <asm/smtc.h>
24#include <asm/smtc_ipi.h>
25#include <asm/smtc_proc.h> 41#include <asm/smtc_proc.h>
26 42
27/* 43/*
@@ -58,11 +74,6 @@ unsigned long irq_hwmask[NR_IRQS];
58 74
59asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS]; 75asiduse smtc_live_asid[MAX_SMTC_TLBS][MAX_SMTC_ASIDS];
60 76
61/*
62 * Clock interrupt "latch" buffers, per "CPU"
63 */
64
65static atomic_t ipi_timer_latch[NR_CPUS];
66 77
67/* 78/*
68 * Number of InterProcessor Interrupt (IPI) message buffers to allocate 79 * Number of InterProcessor Interrupt (IPI) message buffers to allocate
@@ -282,7 +293,7 @@ static void smtc_configure_tlb(void)
282 * phys_cpu_present_map and the logical/physical mappings. 293 * phys_cpu_present_map and the logical/physical mappings.
283 */ 294 */
284 295
285int __init mipsmt_build_cpu_map(int start_cpu_slot) 296int __init smtc_build_cpu_map(int start_cpu_slot)
286{ 297{
287 int i, ntcs; 298 int i, ntcs;
288 299
@@ -325,7 +336,12 @@ static void smtc_tc_setup(int vpe, int tc, int cpu)
325 write_tc_c0_tcstatus((read_tc_c0_tcstatus() 336 write_tc_c0_tcstatus((read_tc_c0_tcstatus()
326 & ~(TCSTATUS_TKSU | TCSTATUS_DA | TCSTATUS_IXMT)) 337 & ~(TCSTATUS_TKSU | TCSTATUS_DA | TCSTATUS_IXMT))
327 | TCSTATUS_A); 338 | TCSTATUS_A);
328 write_tc_c0_tccontext(0); 339 /*
340 * TCContext gets an offset from the base of the IPIQ array
341 * to be used in low-level code to detect the presence of
342 * an active IPI queue
343 */
344 write_tc_c0_tccontext((sizeof(struct smtc_ipi_q) * cpu) << 16);
329 /* Bind tc to vpe */ 345 /* Bind tc to vpe */
330 write_tc_c0_tcbind(vpe); 346 write_tc_c0_tcbind(vpe);
331 /* In general, all TCs should have the same cpu_data indications */ 347 /* In general, all TCs should have the same cpu_data indications */
@@ -336,10 +352,18 @@ static void smtc_tc_setup(int vpe, int tc, int cpu)
336 cpu_data[cpu].options &= ~MIPS_CPU_FPU; 352 cpu_data[cpu].options &= ~MIPS_CPU_FPU;
337 cpu_data[cpu].vpe_id = vpe; 353 cpu_data[cpu].vpe_id = vpe;
338 cpu_data[cpu].tc_id = tc; 354 cpu_data[cpu].tc_id = tc;
355 /* Multi-core SMTC hasn't been tested, but be prepared */
356 cpu_data[cpu].core = (read_vpe_c0_ebase() >> 1) & 0xff;
339} 357}
340 358
359/*
360 * Tweak to get Count registes in as close a sync as possible.
361 * Value seems good for 34K-class cores.
362 */
363
364#define CP0_SKEW 8
341 365
342void mipsmt_prepare_cpus(void) 366void smtc_prepare_cpus(int cpus)
343{ 367{
344 int i, vpe, tc, ntc, nvpe, tcpervpe[NR_CPUS], slop, cpu; 368 int i, vpe, tc, ntc, nvpe, tcpervpe[NR_CPUS], slop, cpu;
345 unsigned long flags; 369 unsigned long flags;
@@ -363,13 +387,13 @@ void mipsmt_prepare_cpus(void)
363 IPIQ[i].head = IPIQ[i].tail = NULL; 387 IPIQ[i].head = IPIQ[i].tail = NULL;
364 spin_lock_init(&IPIQ[i].lock); 388 spin_lock_init(&IPIQ[i].lock);
365 IPIQ[i].depth = 0; 389 IPIQ[i].depth = 0;
366 atomic_set(&ipi_timer_latch[i], 0);
367 } 390 }
368 391
369 /* cpu_data index starts at zero */ 392 /* cpu_data index starts at zero */
370 cpu = 0; 393 cpu = 0;
371 cpu_data[cpu].vpe_id = 0; 394 cpu_data[cpu].vpe_id = 0;
372 cpu_data[cpu].tc_id = 0; 395 cpu_data[cpu].tc_id = 0;
396 cpu_data[cpu].core = (read_c0_ebase() >> 1) & 0xff;
373 cpu++; 397 cpu++;
374 398
375 /* Report on boot-time options */ 399 /* Report on boot-time options */
@@ -484,7 +508,8 @@ void mipsmt_prepare_cpus(void)
484 write_vpe_c0_compare(0); 508 write_vpe_c0_compare(0);
485 /* Propagate Config7 */ 509 /* Propagate Config7 */
486 write_vpe_c0_config7(read_c0_config7()); 510 write_vpe_c0_config7(read_c0_config7());
487 write_vpe_c0_count(read_c0_count()); 511 write_vpe_c0_count(read_c0_count() + CP0_SKEW);
512 ehb();
488 } 513 }
489 /* enable multi-threading within VPE */ 514 /* enable multi-threading within VPE */
490 write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() | VPECONTROL_TE); 515 write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() | VPECONTROL_TE);
@@ -585,24 +610,22 @@ void __cpuinit smtc_boot_secondary(int cpu, struct task_struct *idle)
585 610
586void smtc_init_secondary(void) 611void smtc_init_secondary(void)
587{ 612{
588 /*
589 * Start timer on secondary VPEs if necessary.
590 * plat_timer_setup has already have been invoked by init/main
591 * on "boot" TC. Like per_cpu_trap_init() hack, this assumes that
592 * SMTC init code assigns TCs consdecutively and in ascending order
593 * to across available VPEs.
594 */
595 if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
596 ((read_c0_tcbind() & TCBIND_CURVPE)
597 != cpu_data[smp_processor_id() - 1].vpe_id)){
598 write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
599 }
600
601 local_irq_enable(); 613 local_irq_enable();
602} 614}
603 615
604void smtc_smp_finish(void) 616void smtc_smp_finish(void)
605{ 617{
618 int cpu = smp_processor_id();
619
620 /*
621 * Lowest-numbered CPU per VPE starts a clock tick.
622 * Like per_cpu_trap_init() hack, this assumes that
623 * SMTC init code assigns TCs consdecutively and
624 * in ascending order across available VPEs.
625 */
626 if (cpu > 0 && (cpu_data[cpu].vpe_id != cpu_data[cpu - 1].vpe_id))
627 write_c0_compare(read_c0_count() + mips_hpt_frequency/HZ);
628
606 printk("TC %d going on-line as CPU %d\n", 629 printk("TC %d going on-line as CPU %d\n",
607 cpu_data[smp_processor_id()].tc_id, smp_processor_id()); 630 cpu_data[smp_processor_id()].tc_id, smp_processor_id());
608} 631}
@@ -755,6 +778,8 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
755 struct smtc_ipi *pipi; 778 struct smtc_ipi *pipi;
756 unsigned long flags; 779 unsigned long flags;
757 int mtflags; 780 int mtflags;
781 unsigned long tcrestart;
782 extern void r4k_wait_irqoff(void), __pastwait(void);
758 783
759 if (cpu == smp_processor_id()) { 784 if (cpu == smp_processor_id()) {
760 printk("Cannot Send IPI to self!\n"); 785 printk("Cannot Send IPI to self!\n");
@@ -771,8 +796,6 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
771 pipi->arg = (void *)action; 796 pipi->arg = (void *)action;
772 pipi->dest = cpu; 797 pipi->dest = cpu;
773 if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) { 798 if (cpu_data[cpu].vpe_id != cpu_data[smp_processor_id()].vpe_id) {
774 if (type == SMTC_CLOCK_TICK)
775 atomic_inc(&ipi_timer_latch[cpu]);
776 /* If not on same VPE, enqueue and send cross-VPE interrupt */ 799 /* If not on same VPE, enqueue and send cross-VPE interrupt */
777 smtc_ipi_nq(&IPIQ[cpu], pipi); 800 smtc_ipi_nq(&IPIQ[cpu], pipi);
778 LOCK_CORE_PRA(); 801 LOCK_CORE_PRA();
@@ -800,22 +823,29 @@ void smtc_send_ipi(int cpu, int type, unsigned int action)
800 823
801 if ((tcstatus & TCSTATUS_IXMT) != 0) { 824 if ((tcstatus & TCSTATUS_IXMT) != 0) {
802 /* 825 /*
803 * Spin-waiting here can deadlock, 826 * If we're in the the irq-off version of the wait
804 * so we queue the message for the target TC. 827 * loop, we need to force exit from the wait and
828 * do a direct post of the IPI.
829 */
830 if (cpu_wait == r4k_wait_irqoff) {
831 tcrestart = read_tc_c0_tcrestart();
832 if (tcrestart >= (unsigned long)r4k_wait_irqoff
833 && tcrestart < (unsigned long)__pastwait) {
834 write_tc_c0_tcrestart(__pastwait);
835 tcstatus &= ~TCSTATUS_IXMT;
836 write_tc_c0_tcstatus(tcstatus);
837 goto postdirect;
838 }
839 }
840 /*
841 * Otherwise we queue the message for the target TC
842 * to pick up when he does a local_irq_restore()
805 */ 843 */
806 write_tc_c0_tchalt(0); 844 write_tc_c0_tchalt(0);
807 UNLOCK_CORE_PRA(); 845 UNLOCK_CORE_PRA();
808 /* Try to reduce redundant timer interrupt messages */
809 if (type == SMTC_CLOCK_TICK) {
810 if (atomic_postincrement(&ipi_timer_latch[cpu])!=0){
811 smtc_ipi_nq(&freeIPIq, pipi);
812 return;
813 }
814 }
815 smtc_ipi_nq(&IPIQ[cpu], pipi); 846 smtc_ipi_nq(&IPIQ[cpu], pipi);
816 } else { 847 } else {
817 if (type == SMTC_CLOCK_TICK) 848postdirect:
818 atomic_inc(&ipi_timer_latch[cpu]);
819 post_direct_ipi(cpu, pipi); 849 post_direct_ipi(cpu, pipi);
820 write_tc_c0_tchalt(0); 850 write_tc_c0_tchalt(0);
821 UNLOCK_CORE_PRA(); 851 UNLOCK_CORE_PRA();
@@ -883,7 +913,7 @@ static void ipi_call_interrupt(void)
883 smp_call_function_interrupt(); 913 smp_call_function_interrupt();
884} 914}
885 915
886DECLARE_PER_CPU(struct clock_event_device, smtc_dummy_clockevent_device); 916DECLARE_PER_CPU(struct clock_event_device, mips_clockevent_device);
887 917
888void ipi_decode(struct smtc_ipi *pipi) 918void ipi_decode(struct smtc_ipi *pipi)
889{ 919{
@@ -891,20 +921,13 @@ void ipi_decode(struct smtc_ipi *pipi)
891 struct clock_event_device *cd; 921 struct clock_event_device *cd;
892 void *arg_copy = pipi->arg; 922 void *arg_copy = pipi->arg;
893 int type_copy = pipi->type; 923 int type_copy = pipi->type;
894 int ticks;
895
896 smtc_ipi_nq(&freeIPIq, pipi); 924 smtc_ipi_nq(&freeIPIq, pipi);
897 switch (type_copy) { 925 switch (type_copy) {
898 case SMTC_CLOCK_TICK: 926 case SMTC_CLOCK_TICK:
899 irq_enter(); 927 irq_enter();
900 kstat_this_cpu.irqs[MIPS_CPU_IRQ_BASE + 1]++; 928 kstat_this_cpu.irqs[MIPS_CPU_IRQ_BASE + 1]++;
901 cd = &per_cpu(smtc_dummy_clockevent_device, cpu); 929 cd = &per_cpu(mips_clockevent_device, cpu);
902 ticks = atomic_read(&ipi_timer_latch[cpu]); 930 cd->event_handler(cd);
903 atomic_sub(ticks, &ipi_timer_latch[cpu]);
904 while (ticks) {
905 cd->event_handler(cd);
906 ticks--;
907 }
908 irq_exit(); 931 irq_exit();
909 break; 932 break;
910 933
@@ -937,24 +960,48 @@ void ipi_decode(struct smtc_ipi *pipi)
937 } 960 }
938} 961}
939 962
963/*
964 * Similar to smtc_ipi_replay(), but invoked from context restore,
965 * so it reuses the current exception frame rather than set up a
966 * new one with self_ipi.
967 */
968
940void deferred_smtc_ipi(void) 969void deferred_smtc_ipi(void)
941{ 970{
942 struct smtc_ipi *pipi; 971 int cpu = smp_processor_id();
943 unsigned long flags;
944/* DEBUG */
945 int q = smp_processor_id();
946 972
947 /* 973 /*
948 * Test is not atomic, but much faster than a dequeue, 974 * Test is not atomic, but much faster than a dequeue,
949 * and the vast majority of invocations will have a null queue. 975 * and the vast majority of invocations will have a null queue.
976 * If irq_disabled when this was called, then any IPIs queued
977 * after we test last will be taken on the next irq_enable/restore.
978 * If interrupts were enabled, then any IPIs added after the
979 * last test will be taken directly.
950 */ 980 */
951 if (IPIQ[q].head != NULL) { 981
952 while((pipi = smtc_ipi_dq(&IPIQ[q])) != NULL) { 982 while (IPIQ[cpu].head != NULL) {
953 /* ipi_decode() should be called with interrupts off */ 983 struct smtc_ipi_q *q = &IPIQ[cpu];
954 local_irq_save(flags); 984 struct smtc_ipi *pipi;
985 unsigned long flags;
986
987 /*
988 * It may be possible we'll come in with interrupts
989 * already enabled.
990 */
991 local_irq_save(flags);
992
993 spin_lock(&q->lock);
994 pipi = __smtc_ipi_dq(q);
995 spin_unlock(&q->lock);
996 if (pipi != NULL)
955 ipi_decode(pipi); 997 ipi_decode(pipi);
956 local_irq_restore(flags); 998 /*
957 } 999 * The use of the __raw_local restore isn't
1000 * as obviously necessary here as in smtc_ipi_replay(),
1001 * but it's more efficient, given that we're already
1002 * running down the IPI queue.
1003 */
1004 __raw_local_irq_restore(flags);
958 } 1005 }
959} 1006}
960 1007
@@ -1066,55 +1113,53 @@ static void setup_cross_vpe_interrupts(unsigned int nvpe)
1066 1113
1067/* 1114/*
1068 * SMTC-specific hacks invoked from elsewhere in the kernel. 1115 * SMTC-specific hacks invoked from elsewhere in the kernel.
1069 *
1070 * smtc_ipi_replay is called from raw_local_irq_restore which is only ever
1071 * called with interrupts disabled. We do rely on interrupts being disabled
1072 * here because using spin_lock_irqsave()/spin_unlock_irqrestore() would
1073 * result in a recursive call to raw_local_irq_restore().
1074 */ 1116 */
1075 1117
1076static void __smtc_ipi_replay(void) 1118 /*
1119 * smtc_ipi_replay is called from raw_local_irq_restore
1120 */
1121
1122void smtc_ipi_replay(void)
1077{ 1123{
1078 unsigned int cpu = smp_processor_id(); 1124 unsigned int cpu = smp_processor_id();
1079 1125
1080 /* 1126 /*
1081 * To the extent that we've ever turned interrupts off, 1127 * To the extent that we've ever turned interrupts off,
1082 * we may have accumulated deferred IPIs. This is subtle. 1128 * we may have accumulated deferred IPIs. This is subtle.
1083 * If we use the smtc_ipi_qdepth() macro, we'll get an
1084 * exact number - but we'll also disable interrupts
1085 * and create a window of failure where a new IPI gets
1086 * queued after we test the depth but before we re-enable
1087 * interrupts. So long as IXMT never gets set, however,
1088 * we should be OK: If we pick up something and dispatch 1129 * we should be OK: If we pick up something and dispatch
1089 * it here, that's great. If we see nothing, but concurrent 1130 * it here, that's great. If we see nothing, but concurrent
1090 * with this operation, another TC sends us an IPI, IXMT 1131 * with this operation, another TC sends us an IPI, IXMT
1091 * is clear, and we'll handle it as a real pseudo-interrupt 1132 * is clear, and we'll handle it as a real pseudo-interrupt
1092 * and not a pseudo-pseudo interrupt. 1133 * and not a pseudo-pseudo interrupt. The important thing
1134 * is to do the last check for queued message *after* the
1135 * re-enabling of interrupts.
1093 */ 1136 */
1094 if (IPIQ[cpu].depth > 0) { 1137 while (IPIQ[cpu].head != NULL) {
1095 while (1) { 1138 struct smtc_ipi_q *q = &IPIQ[cpu];
1096 struct smtc_ipi_q *q = &IPIQ[cpu]; 1139 struct smtc_ipi *pipi;
1097 struct smtc_ipi *pipi; 1140 unsigned long flags;
1098 extern void self_ipi(struct smtc_ipi *);
1099
1100 spin_lock(&q->lock);
1101 pipi = __smtc_ipi_dq(q);
1102 spin_unlock(&q->lock);
1103 if (!pipi)
1104 break;
1105 1141
1142 /*
1143 * It's just possible we'll come in with interrupts
1144 * already enabled.
1145 */
1146 local_irq_save(flags);
1147
1148 spin_lock(&q->lock);
1149 pipi = __smtc_ipi_dq(q);
1150 spin_unlock(&q->lock);
1151 /*
1152 ** But use a raw restore here to avoid recursion.
1153 */
1154 __raw_local_irq_restore(flags);
1155
1156 if (pipi) {
1106 self_ipi(pipi); 1157 self_ipi(pipi);
1107 smtc_cpu_stats[cpu].selfipis++; 1158 smtc_cpu_stats[cpu].selfipis++;
1108 } 1159 }
1109 } 1160 }
1110} 1161}
1111 1162
1112void smtc_ipi_replay(void)
1113{
1114 raw_local_irq_disable();
1115 __smtc_ipi_replay();
1116}
1117
1118EXPORT_SYMBOL(smtc_ipi_replay); 1163EXPORT_SYMBOL(smtc_ipi_replay);
1119 1164
1120void smtc_idle_loop_hook(void) 1165void smtc_idle_loop_hook(void)
@@ -1193,40 +1238,13 @@ void smtc_idle_loop_hook(void)
1193 } 1238 }
1194 } 1239 }
1195 1240
1196 /*
1197 * Now that we limit outstanding timer IPIs, check for hung TC
1198 */
1199 for (tc = 0; tc < NR_CPUS; tc++) {
1200 /* Don't check ourself - we'll dequeue IPIs just below */
1201 if ((tc != smp_processor_id()) &&
1202 atomic_read(&ipi_timer_latch[tc]) > timerq_limit) {
1203 if (clock_hang_reported[tc] == 0) {
1204 pdb_msg += sprintf(pdb_msg,
1205 "TC %d looks hung with timer latch at %d\n",
1206 tc, atomic_read(&ipi_timer_latch[tc]));
1207 clock_hang_reported[tc]++;
1208 }
1209 }
1210 }
1211 emt(mtflags); 1241 emt(mtflags);
1212 local_irq_restore(flags); 1242 local_irq_restore(flags);
1213 if (pdb_msg != &id_ho_db_msg[0]) 1243 if (pdb_msg != &id_ho_db_msg[0])
1214 printk("CPU%d: %s", smp_processor_id(), id_ho_db_msg); 1244 printk("CPU%d: %s", smp_processor_id(), id_ho_db_msg);
1215#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */ 1245#endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */
1216 1246
1217 /* 1247 smtc_ipi_replay();
1218 * Replay any accumulated deferred IPIs. If "Instant Replay"
1219 * is in use, there should never be any.
1220 */
1221#ifndef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
1222 {
1223 unsigned long flags;
1224
1225 local_irq_save(flags);
1226 __smtc_ipi_replay();
1227 local_irq_restore(flags);
1228 }
1229#endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
1230} 1248}
1231 1249
1232void smtc_soft_dump(void) 1250void smtc_soft_dump(void)
@@ -1242,10 +1260,6 @@ void smtc_soft_dump(void)
1242 printk("%d: %ld\n", i, smtc_cpu_stats[i].selfipis); 1260 printk("%d: %ld\n", i, smtc_cpu_stats[i].selfipis);
1243 } 1261 }
1244 smtc_ipi_qdump(); 1262 smtc_ipi_qdump();
1245 printk("Timer IPI Backlogs:\n");
1246 for (i=0; i < NR_CPUS; i++) {
1247 printk("%d: %d\n", i, atomic_read(&ipi_timer_latch[i]));
1248 }
1249 printk("%d Recoveries of \"stolen\" FPU\n", 1263 printk("%d Recoveries of \"stolen\" FPU\n",
1250 atomic_read(&smtc_fpu_recoveries)); 1264 atomic_read(&smtc_fpu_recoveries));
1251} 1265}
diff --git a/arch/mips/mti-malta/malta-smtc.c b/arch/mips/mti-malta/malta-smtc.c
index 5ea705e4945..f84a46a8ae6 100644
--- a/arch/mips/mti-malta/malta-smtc.c
+++ b/arch/mips/mti-malta/malta-smtc.c
@@ -84,12 +84,17 @@ static void msmtc_cpus_done(void)
84 84
85static void __init msmtc_smp_setup(void) 85static void __init msmtc_smp_setup(void)
86{ 86{
87 mipsmt_build_cpu_map(0); 87 /*
88 * we won't get the definitive value until
89 * we've run smtc_prepare_cpus later, but
90 * we would appear to need an upper bound now.
91 */
92 smp_num_siblings = smtc_build_cpu_map(0);
88} 93}
89 94
90static void __init msmtc_prepare_cpus(unsigned int max_cpus) 95static void __init msmtc_prepare_cpus(unsigned int max_cpus)
91{ 96{
92 mipsmt_prepare_cpus(); 97 smtc_prepare_cpus(max_cpus);
93} 98}
94 99
95struct plat_smp_ops msmtc_smp_ops = { 100struct plat_smp_ops msmtc_smp_ops = {
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-22 02:28:27 -0500