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-rw-r--r--arch/x86/kernel/nmi_32.c467
1 files changed, 0 insertions, 467 deletions
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
deleted file mode 100644
index 84160f74eeb..00000000000
--- a/arch/x86/kernel/nmi_32.c
+++ /dev/null
@@ -1,467 +0,0 @@
1/*
2 * NMI watchdog support on APIC systems
3 *
4 * Started by Ingo Molnar <mingo@redhat.com>
5 *
6 * Fixes:
7 * Mikael Pettersson : AMD K7 support for local APIC NMI watchdog.
8 * Mikael Pettersson : Power Management for local APIC NMI watchdog.
9 * Mikael Pettersson : Pentium 4 support for local APIC NMI watchdog.
10 * Pavel Machek and
11 * Mikael Pettersson : PM converted to driver model. Disable/enable API.
12 */
13
14#include <linux/delay.h>
15#include <linux/interrupt.h>
16#include <linux/module.h>
17#include <linux/nmi.h>
18#include <linux/sysdev.h>
19#include <linux/sysctl.h>
20#include <linux/percpu.h>
21#include <linux/kprobes.h>
22#include <linux/cpumask.h>
23#include <linux/kernel_stat.h>
24#include <linux/kdebug.h>
25#include <linux/slab.h>
26
27#include <asm/smp.h>
28#include <asm/nmi.h>
29
30#include "mach_traps.h"
31
32int unknown_nmi_panic;
33int nmi_watchdog_enabled;
34
35static cpumask_t backtrace_mask = CPU_MASK_NONE;
36
37/* nmi_active:
38 * >0: the lapic NMI watchdog is active, but can be disabled
39 * <0: the lapic NMI watchdog has not been set up, and cannot
40 * be enabled
41 * 0: the lapic NMI watchdog is disabled, but can be enabled
42 */
43atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
44
45unsigned int nmi_watchdog = NMI_DEFAULT;
46static unsigned int nmi_hz = HZ;
47
48static DEFINE_PER_CPU(short, wd_enabled);
49
50static int endflag __initdata = 0;
51
52#ifdef CONFIG_SMP
53/* The performance counters used by NMI_LOCAL_APIC don't trigger when
54 * the CPU is idle. To make sure the NMI watchdog really ticks on all
55 * CPUs during the test make them busy.
56 */
57static __init void nmi_cpu_busy(void *data)
58{
59 local_irq_enable_in_hardirq();
60 /* Intentionally don't use cpu_relax here. This is
61 to make sure that the performance counter really ticks,
62 even if there is a simulator or similar that catches the
63 pause instruction. On a real HT machine this is fine because
64 all other CPUs are busy with "useless" delay loops and don't
65 care if they get somewhat less cycles. */
66 while (endflag == 0)
67 mb();
68}
69#endif
70
71int __init check_nmi_watchdog(void)
72{
73 unsigned int *prev_nmi_count;
74 int cpu;
75
76 if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED))
77 return 0;
78
79 if (!atomic_read(&nmi_active))
80 return 0;
81
82 prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
83 if (!prev_nmi_count)
84 return -1;
85
86 printk(KERN_INFO "Testing NMI watchdog ... ");
87
88#ifdef CONFIG_SMP
89 if (nmi_watchdog == NMI_LOCAL_APIC)
90 smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0);
91#endif
92
93 for_each_possible_cpu(cpu)
94 prev_nmi_count[cpu] = nmi_count(cpu);
95 local_irq_enable();
96 mdelay((20*1000)/nmi_hz); // wait 20 ticks
97
98 for_each_possible_cpu(cpu) {
99#ifdef CONFIG_SMP
100 /* Check cpu_callin_map here because that is set
101 after the timer is started. */
102 if (!cpu_isset(cpu, cpu_callin_map))
103 continue;
104#endif
105 if (!per_cpu(wd_enabled, cpu))
106 continue;
107 if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
108 printk(KERN_WARNING "WARNING: CPU#%d: NMI "
109 "appears to be stuck (%d->%d)!\n",
110 cpu,
111 prev_nmi_count[cpu],
112 nmi_count(cpu));
113 per_cpu(wd_enabled, cpu) = 0;
114 atomic_dec(&nmi_active);
115 }
116 }
117 endflag = 1;
118 if (!atomic_read(&nmi_active)) {
119 kfree(prev_nmi_count);
120 atomic_set(&nmi_active, -1);
121 return -1;
122 }
123 printk("OK.\n");
124
125 /* now that we know it works we can reduce NMI frequency to
126 something more reasonable; makes a difference in some configs */
127 if (nmi_watchdog == NMI_LOCAL_APIC)
128 nmi_hz = lapic_adjust_nmi_hz(1);
129
130 kfree(prev_nmi_count);
131 return 0;
132}
133
134static int __init setup_nmi_watchdog(char *str)
135{
136 int nmi;
137
138 get_option(&str, &nmi);
139
140 if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
141 return 0;
142
143 nmi_watchdog = nmi;
144 return 1;
145}
146
147__setup("nmi_watchdog=", setup_nmi_watchdog);
148
149
150/* Suspend/resume support */
151
152#ifdef CONFIG_PM
153
154static int nmi_pm_active; /* nmi_active before suspend */
155
156static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
157{
158 /* only CPU0 goes here, other CPUs should be offline */
159 nmi_pm_active = atomic_read(&nmi_active);
160 stop_apic_nmi_watchdog(NULL);
161 BUG_ON(atomic_read(&nmi_active) != 0);
162 return 0;
163}
164
165static int lapic_nmi_resume(struct sys_device *dev)
166{
167 /* only CPU0 goes here, other CPUs should be offline */
168 if (nmi_pm_active > 0) {
169 setup_apic_nmi_watchdog(NULL);
170 touch_nmi_watchdog();
171 }
172 return 0;
173}
174
175
176static struct sysdev_class nmi_sysclass = {
177 .name = "lapic_nmi",
178 .resume = lapic_nmi_resume,
179 .suspend = lapic_nmi_suspend,
180};
181
182static struct sys_device device_lapic_nmi = {
183 .id = 0,
184 .cls = &nmi_sysclass,
185};
186
187static int __init init_lapic_nmi_sysfs(void)
188{
189 int error;
190
191 /* should really be a BUG_ON but b/c this is an
192 * init call, it just doesn't work. -dcz
193 */
194 if (nmi_watchdog != NMI_LOCAL_APIC)
195 return 0;
196
197 if (atomic_read(&nmi_active) < 0)
198 return 0;
199
200 error = sysdev_class_register(&nmi_sysclass);
201 if (!error)
202 error = sysdev_register(&device_lapic_nmi);
203 return error;
204}
205/* must come after the local APIC's device_initcall() */
206late_initcall(init_lapic_nmi_sysfs);
207
208#endif /* CONFIG_PM */
209
210static void __acpi_nmi_enable(void *__unused)
211{
212 apic_write_around(APIC_LVT0, APIC_DM_NMI);
213}
214
215/*
216 * Enable timer based NMIs on all CPUs:
217 */
218void acpi_nmi_enable(void)
219{
220 if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
221 on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
222}
223
224static void __acpi_nmi_disable(void *__unused)
225{
226 apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
227}
228
229/*
230 * Disable timer based NMIs on all CPUs:
231 */
232void acpi_nmi_disable(void)
233{
234 if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
235 on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
236}
237
238void setup_apic_nmi_watchdog(void *unused)
239{
240 if (__get_cpu_var(wd_enabled))
241 return;
242
243 /* cheap hack to support suspend/resume */
244 /* if cpu0 is not active neither should the other cpus */
245 if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
246 return;
247
248 switch (nmi_watchdog) {
249 case NMI_LOCAL_APIC:
250 __get_cpu_var(wd_enabled) = 1; /* enable it before to avoid race with handler */
251 if (lapic_watchdog_init(nmi_hz) < 0) {
252 __get_cpu_var(wd_enabled) = 0;
253 return;
254 }
255 /* FALL THROUGH */
256 case NMI_IO_APIC:
257 __get_cpu_var(wd_enabled) = 1;
258 atomic_inc(&nmi_active);
259 }
260}
261
262void stop_apic_nmi_watchdog(void *unused)
263{
264 /* only support LOCAL and IO APICs for now */
265 if ((nmi_watchdog != NMI_LOCAL_APIC) &&
266 (nmi_watchdog != NMI_IO_APIC))
267 return;
268 if (__get_cpu_var(wd_enabled) == 0)
269 return;
270 if (nmi_watchdog == NMI_LOCAL_APIC)
271 lapic_watchdog_stop();
272 __get_cpu_var(wd_enabled) = 0;
273 atomic_dec(&nmi_active);
274}
275
276/*
277 * the best way to detect whether a CPU has a 'hard lockup' problem
278 * is to check it's local APIC timer IRQ counts. If they are not
279 * changing then that CPU has some problem.
280 *
281 * as these watchdog NMI IRQs are generated on every CPU, we only
282 * have to check the current processor.
283 *
284 * since NMIs don't listen to _any_ locks, we have to be extremely
285 * careful not to rely on unsafe variables. The printk might lock
286 * up though, so we have to break up any console locks first ...
287 * [when there will be more tty-related locks, break them up
288 * here too!]
289 */
290
291static unsigned int
292 last_irq_sums [NR_CPUS],
293 alert_counter [NR_CPUS];
294
295void touch_nmi_watchdog(void)
296{
297 if (nmi_watchdog > 0) {
298 unsigned cpu;
299
300 /*
301 * Just reset the alert counters, (other CPUs might be
302 * spinning on locks we hold):
303 */
304 for_each_present_cpu(cpu) {
305 if (alert_counter[cpu])
306 alert_counter[cpu] = 0;
307 }
308 }
309
310 /*
311 * Tickle the softlockup detector too:
312 */
313 touch_softlockup_watchdog();
314}
315EXPORT_SYMBOL(touch_nmi_watchdog);
316
317extern void die_nmi(struct pt_regs *, const char *msg);
318
319notrace __kprobes int
320nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
321{
322
323 /*
324 * Since current_thread_info()-> is always on the stack, and we
325 * always switch the stack NMI-atomically, it's safe to use
326 * smp_processor_id().
327 */
328 unsigned int sum;
329 int touched = 0;
330 int cpu = smp_processor_id();
331 int rc = 0;
332
333 /* check for other users first */
334 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
335 == NOTIFY_STOP) {
336 rc = 1;
337 touched = 1;
338 }
339
340 if (cpu_isset(cpu, backtrace_mask)) {
341 static DEFINE_SPINLOCK(lock); /* Serialise the printks */
342
343 spin_lock(&lock);
344 printk("NMI backtrace for cpu %d\n", cpu);
345 dump_stack();
346 spin_unlock(&lock);
347 cpu_clear(cpu, backtrace_mask);
348 }
349
350 /*
351 * Take the local apic timer and PIT/HPET into account. We don't
352 * know which one is active, when we have highres/dyntick on
353 */
354 sum = per_cpu(irq_stat, cpu).apic_timer_irqs +
355 per_cpu(irq_stat, cpu).irq0_irqs;
356
357 /* if the none of the timers isn't firing, this cpu isn't doing much */
358 if (!touched && last_irq_sums[cpu] == sum) {
359 /*
360 * Ayiee, looks like this CPU is stuck ...
361 * wait a few IRQs (5 seconds) before doing the oops ...
362 */
363 alert_counter[cpu]++;
364 if (alert_counter[cpu] == 5*nmi_hz)
365 /*
366 * die_nmi will return ONLY if NOTIFY_STOP happens..
367 */
368 die_nmi(regs, "BUG: NMI Watchdog detected LOCKUP");
369 } else {
370 last_irq_sums[cpu] = sum;
371 alert_counter[cpu] = 0;
372 }
373 /* see if the nmi watchdog went off */
374 if (!__get_cpu_var(wd_enabled))
375 return rc;
376 switch (nmi_watchdog) {
377 case NMI_LOCAL_APIC:
378 rc |= lapic_wd_event(nmi_hz);
379 break;
380 case NMI_IO_APIC:
381 /* don't know how to accurately check for this.
382 * just assume it was a watchdog timer interrupt
383 * This matches the old behaviour.
384 */
385 rc = 1;
386 break;
387 }
388 return rc;
389}
390
391#ifdef CONFIG_SYSCTL
392
393static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
394{
395 unsigned char reason = get_nmi_reason();
396 char buf[64];
397
398 sprintf(buf, "NMI received for unknown reason %02x\n", reason);
399 die_nmi(regs, buf);
400 return 0;
401}
402
403/*
404 * proc handler for /proc/sys/kernel/nmi
405 */
406int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
407 void __user *buffer, size_t *length, loff_t *ppos)
408{
409 int old_state;
410
411 nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
412 old_state = nmi_watchdog_enabled;
413 proc_dointvec(table, write, file, buffer, length, ppos);
414 if (!!old_state == !!nmi_watchdog_enabled)
415 return 0;
416
417 if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
418 printk( KERN_WARNING "NMI watchdog is permanently disabled\n");
419 return -EIO;
420 }
421
422 if (nmi_watchdog == NMI_DEFAULT) {
423 if (lapic_watchdog_ok())
424 nmi_watchdog = NMI_LOCAL_APIC;
425 else
426 nmi_watchdog = NMI_IO_APIC;
427 }
428
429 if (nmi_watchdog == NMI_LOCAL_APIC) {
430 if (nmi_watchdog_enabled)
431 enable_lapic_nmi_watchdog();
432 else
433 disable_lapic_nmi_watchdog();
434 } else {
435 printk( KERN_WARNING
436 "NMI watchdog doesn't know what hardware to touch\n");
437 return -EIO;
438 }
439 return 0;
440}
441
442#endif
443
444int do_nmi_callback(struct pt_regs *regs, int cpu)
445{
446#ifdef CONFIG_SYSCTL
447 if (unknown_nmi_panic)
448 return unknown_nmi_panic_callback(regs, cpu);
449#endif
450 return 0;
451}
452
453void __trigger_all_cpu_backtrace(void)
454{
455 int i;
456
457 backtrace_mask = cpu_online_map;
458 /* Wait for up to 10 seconds for all CPUs to do the backtrace */
459 for (i = 0; i < 10 * 1000; i++) {
460 if (cpus_empty(backtrace_mask))
461 break;
462 mdelay(1);
463 }
464}
465
466EXPORT_SYMBOL(nmi_active);
467EXPORT_SYMBOL(nmi_watchdog);
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