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-rw-r--r--arch/x86/kernel/nmi_64.c482
1 files changed, 0 insertions, 482 deletions
diff --git a/arch/x86/kernel/nmi_64.c b/arch/x86/kernel/nmi_64.c
deleted file mode 100644
index 5a29ded994fa..000000000000
--- a/arch/x86/kernel/nmi_64.c
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@@ -1,482 +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 * Pavel Machek and
10 * Mikael Pettersson : PM converted to driver model. Disable/enable API.
11 */
12
13#include <linux/nmi.h>
14#include <linux/mm.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include <linux/module.h>
18#include <linux/sysdev.h>
19#include <linux/sysctl.h>
20#include <linux/kprobes.h>
21#include <linux/cpumask.h>
22#include <linux/kdebug.h>
23
24#include <asm/smp.h>
25#include <asm/nmi.h>
26#include <asm/proto.h>
27#include <asm/mce.h>
28
29#include <mach_traps.h>
30
31int unknown_nmi_panic;
32int nmi_watchdog_enabled;
33int panic_on_unrecovered_nmi;
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 */
44static int panic_on_timeout;
45
46unsigned int nmi_watchdog = NMI_DEFAULT;
47static unsigned int nmi_hz = HZ;
48
49static DEFINE_PER_CPU(short, wd_enabled);
50
51/* Run after command line and cpu_init init, but before all other checks */
52void nmi_watchdog_default(void)
53{
54 if (nmi_watchdog != NMI_DEFAULT)
55 return;
56 nmi_watchdog = NMI_NONE;
57}
58
59static int endflag __initdata = 0;
60
61#ifdef CONFIG_SMP
62/* The performance counters used by NMI_LOCAL_APIC don't trigger when
63 * the CPU is idle. To make sure the NMI watchdog really ticks on all
64 * CPUs during the test make them busy.
65 */
66static __init void nmi_cpu_busy(void *data)
67{
68 local_irq_enable_in_hardirq();
69 /* Intentionally don't use cpu_relax here. This is
70 to make sure that the performance counter really ticks,
71 even if there is a simulator or similar that catches the
72 pause instruction. On a real HT machine this is fine because
73 all other CPUs are busy with "useless" delay loops and don't
74 care if they get somewhat less cycles. */
75 while (endflag == 0)
76 mb();
77}
78#endif
79
80int __init check_nmi_watchdog(void)
81{
82 int *prev_nmi_count;
83 int cpu;
84
85 if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED))
86 return 0;
87
88 if (!atomic_read(&nmi_active))
89 return 0;
90
91 prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
92 if (!prev_nmi_count)
93 return -1;
94
95 printk(KERN_INFO "Testing NMI watchdog ... ");
96
97#ifdef CONFIG_SMP
98 if (nmi_watchdog == NMI_LOCAL_APIC)
99 smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0);
100#endif
101
102 for (cpu = 0; cpu < NR_CPUS; cpu++)
103 prev_nmi_count[cpu] = cpu_pda(cpu)->__nmi_count;
104 local_irq_enable();
105 mdelay((20*1000)/nmi_hz); // wait 20 ticks
106
107 for_each_online_cpu(cpu) {
108 if (!per_cpu(wd_enabled, cpu))
109 continue;
110 if (cpu_pda(cpu)->__nmi_count - prev_nmi_count[cpu] <= 5) {
111 printk(KERN_WARNING "WARNING: CPU#%d: NMI "
112 "appears to be stuck (%d->%d)!\n",
113 cpu,
114 prev_nmi_count[cpu],
115 cpu_pda(cpu)->__nmi_count);
116 per_cpu(wd_enabled, cpu) = 0;
117 atomic_dec(&nmi_active);
118 }
119 }
120 endflag = 1;
121 if (!atomic_read(&nmi_active)) {
122 kfree(prev_nmi_count);
123 atomic_set(&nmi_active, -1);
124 return -1;
125 }
126 printk("OK.\n");
127
128 /* now that we know it works we can reduce NMI frequency to
129 something more reasonable; makes a difference in some configs */
130 if (nmi_watchdog == NMI_LOCAL_APIC)
131 nmi_hz = lapic_adjust_nmi_hz(1);
132
133 kfree(prev_nmi_count);
134 return 0;
135}
136
137static int __init setup_nmi_watchdog(char *str)
138{
139 int nmi;
140
141 if (!strncmp(str,"panic",5)) {
142 panic_on_timeout = 1;
143 str = strchr(str, ',');
144 if (!str)
145 return 1;
146 ++str;
147 }
148
149 get_option(&str, &nmi);
150
151 if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
152 return 0;
153
154 nmi_watchdog = nmi;
155 return 1;
156}
157
158__setup("nmi_watchdog=", setup_nmi_watchdog);
159
160#ifdef CONFIG_PM
161
162static int nmi_pm_active; /* nmi_active before suspend */
163
164static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
165{
166 /* only CPU0 goes here, other CPUs should be offline */
167 nmi_pm_active = atomic_read(&nmi_active);
168 stop_apic_nmi_watchdog(NULL);
169 BUG_ON(atomic_read(&nmi_active) != 0);
170 return 0;
171}
172
173static int lapic_nmi_resume(struct sys_device *dev)
174{
175 /* only CPU0 goes here, other CPUs should be offline */
176 if (nmi_pm_active > 0) {
177 setup_apic_nmi_watchdog(NULL);
178 touch_nmi_watchdog();
179 }
180 return 0;
181}
182
183static struct sysdev_class nmi_sysclass = {
184 .name = "lapic_nmi",
185 .resume = lapic_nmi_resume,
186 .suspend = lapic_nmi_suspend,
187};
188
189static struct sys_device device_lapic_nmi = {
190 .id = 0,
191 .cls = &nmi_sysclass,
192};
193
194static int __init init_lapic_nmi_sysfs(void)
195{
196 int error;
197
198 /* should really be a BUG_ON but b/c this is an
199 * init call, it just doesn't work. -dcz
200 */
201 if (nmi_watchdog != NMI_LOCAL_APIC)
202 return 0;
203
204 if (atomic_read(&nmi_active) < 0)
205 return 0;
206
207 error = sysdev_class_register(&nmi_sysclass);
208 if (!error)
209 error = sysdev_register(&device_lapic_nmi);
210 return error;
211}
212/* must come after the local APIC's device_initcall() */
213late_initcall(init_lapic_nmi_sysfs);
214
215#endif /* CONFIG_PM */
216
217static void __acpi_nmi_enable(void *__unused)
218{
219 apic_write(APIC_LVT0, APIC_DM_NMI);
220}
221
222/*
223 * Enable timer based NMIs on all CPUs:
224 */
225void acpi_nmi_enable(void)
226{
227 if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
228 on_each_cpu(__acpi_nmi_enable, NULL, 0, 1);
229}
230
231static void __acpi_nmi_disable(void *__unused)
232{
233 apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
234}
235
236/*
237 * Disable timer based NMIs on all CPUs:
238 */
239void acpi_nmi_disable(void)
240{
241 if (atomic_read(&nmi_active) && nmi_watchdog == NMI_IO_APIC)
242 on_each_cpu(__acpi_nmi_disable, NULL, 0, 1);
243}
244
245void setup_apic_nmi_watchdog(void *unused)
246{
247 if (__get_cpu_var(wd_enabled))
248 return;
249
250 /* cheap hack to support suspend/resume */
251 /* if cpu0 is not active neither should the other cpus */
252 if ((smp_processor_id() != 0) && (atomic_read(&nmi_active) <= 0))
253 return;
254
255 switch (nmi_watchdog) {
256 case NMI_LOCAL_APIC:
257 __get_cpu_var(wd_enabled) = 1;
258 if (lapic_watchdog_init(nmi_hz) < 0) {
259 __get_cpu_var(wd_enabled) = 0;
260 return;
261 }
262 /* FALL THROUGH */
263 case NMI_IO_APIC:
264 __get_cpu_var(wd_enabled) = 1;
265 atomic_inc(&nmi_active);
266 }
267}
268
269void stop_apic_nmi_watchdog(void *unused)
270{
271 /* only support LOCAL and IO APICs for now */
272 if ((nmi_watchdog != NMI_LOCAL_APIC) &&
273 (nmi_watchdog != NMI_IO_APIC))
274 return;
275 if (__get_cpu_var(wd_enabled) == 0)
276 return;
277 if (nmi_watchdog == NMI_LOCAL_APIC)
278 lapic_watchdog_stop();
279 __get_cpu_var(wd_enabled) = 0;
280 atomic_dec(&nmi_active);
281}
282
283/*
284 * the best way to detect whether a CPU has a 'hard lockup' problem
285 * is to check it's local APIC timer IRQ counts. If they are not
286 * changing then that CPU has some problem.
287 *
288 * as these watchdog NMI IRQs are generated on every CPU, we only
289 * have to check the current processor.
290 */
291
292static DEFINE_PER_CPU(unsigned, last_irq_sum);
293static DEFINE_PER_CPU(local_t, alert_counter);
294static DEFINE_PER_CPU(int, nmi_touch);
295
296void touch_nmi_watchdog(void)
297{
298 if (nmi_watchdog > 0) {
299 unsigned cpu;
300
301 /*
302 * Tell other CPUs to reset their alert counters. We cannot
303 * do it ourselves because the alert count increase is not
304 * atomic.
305 */
306 for_each_present_cpu(cpu) {
307 if (per_cpu(nmi_touch, cpu) != 1)
308 per_cpu(nmi_touch, cpu) = 1;
309 }
310 }
311
312 touch_softlockup_watchdog();
313}
314EXPORT_SYMBOL(touch_nmi_watchdog);
315
316notrace __kprobes int
317nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
318{
319 int sum;
320 int touched = 0;
321 int cpu = smp_processor_id();
322 int rc = 0;
323
324 /* check for other users first */
325 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
326 == NOTIFY_STOP) {
327 rc = 1;
328 touched = 1;
329 }
330
331 sum = read_pda(apic_timer_irqs) + read_pda(irq0_irqs);
332 if (__get_cpu_var(nmi_touch)) {
333 __get_cpu_var(nmi_touch) = 0;
334 touched = 1;
335 }
336
337 if (cpu_isset(cpu, backtrace_mask)) {
338 static DEFINE_SPINLOCK(lock); /* Serialise the printks */
339
340 spin_lock(&lock);
341 printk("NMI backtrace for cpu %d\n", cpu);
342 dump_stack();
343 spin_unlock(&lock);
344 cpu_clear(cpu, backtrace_mask);
345 }
346
347#ifdef CONFIG_X86_MCE
348 /* Could check oops_in_progress here too, but it's safer
349 not too */
350 if (atomic_read(&mce_entry) > 0)
351 touched = 1;
352#endif
353 /* if the apic timer isn't firing, this cpu isn't doing much */
354 if (!touched && __get_cpu_var(last_irq_sum) == sum) {
355 /*
356 * Ayiee, looks like this CPU is stuck ...
357 * wait a few IRQs (5 seconds) before doing the oops ...
358 */
359 local_inc(&__get_cpu_var(alert_counter));
360 if (local_read(&__get_cpu_var(alert_counter)) == 5*nmi_hz)
361 die_nmi("NMI Watchdog detected LOCKUP on CPU %d\n", regs,
362 panic_on_timeout);
363 } else {
364 __get_cpu_var(last_irq_sum) = sum;
365 local_set(&__get_cpu_var(alert_counter), 0);
366 }
367
368 /* see if the nmi watchdog went off */
369 if (!__get_cpu_var(wd_enabled))
370 return rc;
371 switch (nmi_watchdog) {
372 case NMI_LOCAL_APIC:
373 rc |= lapic_wd_event(nmi_hz);
374 break;
375 case NMI_IO_APIC:
376 /* don't know how to accurately check for this.
377 * just assume it was a watchdog timer interrupt
378 * This matches the old behaviour.
379 */
380 rc = 1;
381 break;
382 }
383 return rc;
384}
385
386static unsigned ignore_nmis;
387
388asmlinkage notrace __kprobes void
389do_nmi(struct pt_regs *regs, long error_code)
390{
391 nmi_enter();
392 add_pda(__nmi_count,1);
393 if (!ignore_nmis)
394 default_do_nmi(regs);
395 nmi_exit();
396}
397
398void stop_nmi(void)
399{
400 acpi_nmi_disable();
401 ignore_nmis++;
402}
403
404void restart_nmi(void)
405{
406 ignore_nmis--;
407 acpi_nmi_enable();
408}
409
410#ifdef CONFIG_SYSCTL
411
412static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
413{
414 unsigned char reason = get_nmi_reason();
415 char buf[64];
416
417 sprintf(buf, "NMI received for unknown reason %02x\n", reason);
418 die_nmi(buf, regs, 1); /* Always panic here */
419 return 0;
420}
421
422/*
423 * proc handler for /proc/sys/kernel/nmi
424 */
425int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
426 void __user *buffer, size_t *length, loff_t *ppos)
427{
428 int old_state;
429
430 nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
431 old_state = nmi_watchdog_enabled;
432 proc_dointvec(table, write, file, buffer, length, ppos);
433 if (!!old_state == !!nmi_watchdog_enabled)
434 return 0;
435
436 if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
437 printk( KERN_WARNING "NMI watchdog is permanently disabled\n");
438 return -EIO;
439 }
440
441 /* if nmi_watchdog is not set yet, then set it */
442 nmi_watchdog_default();
443
444 if (nmi_watchdog == NMI_LOCAL_APIC) {
445 if (nmi_watchdog_enabled)
446 enable_lapic_nmi_watchdog();
447 else
448 disable_lapic_nmi_watchdog();
449 } else {
450 printk( KERN_WARNING
451 "NMI watchdog doesn't know what hardware to touch\n");
452 return -EIO;
453 }
454 return 0;
455}
456
457#endif
458
459int do_nmi_callback(struct pt_regs *regs, int cpu)
460{
461#ifdef CONFIG_SYSCTL
462 if (unknown_nmi_panic)
463 return unknown_nmi_panic_callback(regs, cpu);
464#endif
465 return 0;
466}
467
468void __trigger_all_cpu_backtrace(void)
469{
470 int i;
471
472 backtrace_mask = cpu_online_map;
473 /* Wait for up to 10 seconds for all CPUs to do the backtrace */
474 for (i = 0; i < 10 * 1000; i++) {
475 if (cpus_empty(backtrace_mask))
476 break;
477 mdelay(1);
478 }
479}
480
481EXPORT_SYMBOL(nmi_active);
482EXPORT_SYMBOL(nmi_watchdog);
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