Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Intel specific MCE features. | |
3 | * Copyright 2004 Zwane Mwaikambo <zwane@linuxpower.ca> | |
88ccbedd AK |
4 | * Copyright (C) 2008, 2009 Intel Corporation |
5 | * Author: Andi Kleen | |
1da177e4 LT |
6 | */ |
7 | ||
5a0e3ad6 | 8 | #include <linux/gfp.h> |
1da177e4 LT |
9 | #include <linux/interrupt.h> |
10 | #include <linux/percpu.h> | |
d43c36dc | 11 | #include <linux/sched.h> |
27f6c573 | 12 | #include <linux/cpumask.h> |
1bf7b31e | 13 | #include <asm/apic.h> |
1da177e4 LT |
14 | #include <asm/processor.h> |
15 | #include <asm/msr.h> | |
16 | #include <asm/mce.h> | |
1da177e4 | 17 | |
55babd8f CG |
18 | #include "mce-internal.h" |
19 | ||
88ccbedd AK |
20 | /* |
21 | * Support for Intel Correct Machine Check Interrupts. This allows | |
22 | * the CPU to raise an interrupt when a corrected machine check happened. | |
23 | * Normally we pick those up using a regular polling timer. | |
24 | * Also supports reliable discovery of shared banks. | |
25 | */ | |
26 | ||
0644414e NR |
27 | /* |
28 | * CMCI can be delivered to multiple cpus that share a machine check bank | |
29 | * so we need to designate a single cpu to process errors logged in each bank | |
30 | * in the interrupt handler (otherwise we would have many races and potential | |
31 | * double reporting of the same error). | |
32 | * Note that this can change when a cpu is offlined or brought online since | |
33 | * some MCA banks are shared across cpus. When a cpu is offlined, cmci_clear() | |
34 | * disables CMCI on all banks owned by the cpu and clears this bitfield. At | |
35 | * this point, cmci_rediscover() kicks in and a different cpu may end up | |
36 | * taking ownership of some of the shared MCA banks that were previously | |
37 | * owned by the offlined cpu. | |
38 | */ | |
88ccbedd AK |
39 | static DEFINE_PER_CPU(mce_banks_t, mce_banks_owned); |
40 | ||
3f2f0680 BP |
41 | /* |
42 | * CMCI storm detection backoff counter | |
43 | * | |
44 | * During storm, we reset this counter to INITIAL_CHECK_INTERVAL in case we've | |
45 | * encountered an error. If not, we decrement it by one. We signal the end of | |
46 | * the CMCI storm when it reaches 0. | |
47 | */ | |
48 | static DEFINE_PER_CPU(int, cmci_backoff_cnt); | |
49 | ||
88ccbedd AK |
50 | /* |
51 | * cmci_discover_lock protects against parallel discovery attempts | |
52 | * which could race against each other. | |
53 | */ | |
ed5c41d3 | 54 | static DEFINE_RAW_SPINLOCK(cmci_discover_lock); |
88ccbedd | 55 | |
55babd8f CG |
56 | #define CMCI_THRESHOLD 1 |
57 | #define CMCI_POLL_INTERVAL (30 * HZ) | |
3f2f0680 | 58 | #define CMCI_STORM_INTERVAL (HZ) |
55babd8f CG |
59 | #define CMCI_STORM_THRESHOLD 15 |
60 | ||
61 | static DEFINE_PER_CPU(unsigned long, cmci_time_stamp); | |
62 | static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt); | |
63 | static DEFINE_PER_CPU(unsigned int, cmci_storm_state); | |
64 | ||
65 | enum { | |
66 | CMCI_STORM_NONE, | |
67 | CMCI_STORM_ACTIVE, | |
68 | CMCI_STORM_SUBSIDED, | |
69 | }; | |
70 | ||
71 | static atomic_t cmci_storm_on_cpus; | |
88ccbedd | 72 | |
df20e2eb | 73 | static int cmci_supported(int *banks) |
88ccbedd AK |
74 | { |
75 | u64 cap; | |
76 | ||
7af19e4a | 77 | if (mca_cfg.cmci_disabled || mca_cfg.ignore_ce) |
62fdac59 HS |
78 | return 0; |
79 | ||
88ccbedd AK |
80 | /* |
81 | * Vendor check is not strictly needed, but the initial | |
82 | * initialization is vendor keyed and this | |
83 | * makes sure none of the backdoors are entered otherwise. | |
84 | */ | |
85 | if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) | |
86 | return 0; | |
93984fbd | 87 | if (!boot_cpu_has(X86_FEATURE_APIC) || lapic_get_maxlvt() < 6) |
88ccbedd AK |
88 | return 0; |
89 | rdmsrl(MSR_IA32_MCG_CAP, cap); | |
90 | *banks = min_t(unsigned, MAX_NR_BANKS, cap & 0xff); | |
91 | return !!(cap & MCG_CMCI_P); | |
92 | } | |
93 | ||
88d53867 AR |
94 | static bool lmce_supported(void) |
95 | { | |
96 | u64 tmp; | |
97 | ||
98 | if (mca_cfg.lmce_disabled) | |
99 | return false; | |
100 | ||
101 | rdmsrl(MSR_IA32_MCG_CAP, tmp); | |
102 | ||
103 | /* | |
104 | * LMCE depends on recovery support in the processor. Hence both | |
105 | * MCG_SER_P and MCG_LMCE_P should be present in MCG_CAP. | |
106 | */ | |
107 | if ((tmp & (MCG_SER_P | MCG_LMCE_P)) != | |
108 | (MCG_SER_P | MCG_LMCE_P)) | |
109 | return false; | |
110 | ||
111 | /* | |
112 | * BIOS should indicate support for LMCE by setting bit 20 in | |
113 | * IA32_FEATURE_CONTROL without which touching MCG_EXT_CTL will | |
114 | * generate a #GP fault. | |
115 | */ | |
116 | rdmsrl(MSR_IA32_FEATURE_CONTROL, tmp); | |
117 | if ((tmp & (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE)) == | |
118 | (FEATURE_CONTROL_LOCKED | FEATURE_CONTROL_LMCE)) | |
119 | return true; | |
120 | ||
121 | return false; | |
122 | } | |
123 | ||
3f2f0680 | 124 | bool mce_intel_cmci_poll(void) |
55babd8f CG |
125 | { |
126 | if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE) | |
3f2f0680 BP |
127 | return false; |
128 | ||
129 | /* | |
130 | * Reset the counter if we've logged an error in the last poll | |
131 | * during the storm. | |
132 | */ | |
133 | if (machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned))) | |
134 | this_cpu_write(cmci_backoff_cnt, INITIAL_CHECK_INTERVAL); | |
135 | else | |
136 | this_cpu_dec(cmci_backoff_cnt); | |
137 | ||
138 | return true; | |
55babd8f CG |
139 | } |
140 | ||
141 | void mce_intel_hcpu_update(unsigned long cpu) | |
142 | { | |
143 | if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE) | |
144 | atomic_dec(&cmci_storm_on_cpus); | |
145 | ||
146 | per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE; | |
147 | } | |
148 | ||
1b484655 XX |
149 | static void cmci_toggle_interrupt_mode(bool on) |
150 | { | |
151 | unsigned long flags, *owned; | |
152 | int bank; | |
153 | u64 val; | |
154 | ||
155 | raw_spin_lock_irqsave(&cmci_discover_lock, flags); | |
156 | owned = this_cpu_ptr(mce_banks_owned); | |
157 | for_each_set_bit(bank, owned, MAX_NR_BANKS) { | |
158 | rdmsrl(MSR_IA32_MCx_CTL2(bank), val); | |
159 | ||
160 | if (on) | |
161 | val |= MCI_CTL2_CMCI_EN; | |
162 | else | |
163 | val &= ~MCI_CTL2_CMCI_EN; | |
164 | ||
165 | wrmsrl(MSR_IA32_MCx_CTL2(bank), val); | |
166 | } | |
167 | raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); | |
168 | } | |
169 | ||
3f2f0680 | 170 | unsigned long cmci_intel_adjust_timer(unsigned long interval) |
55babd8f | 171 | { |
3f2f0680 BP |
172 | if ((this_cpu_read(cmci_backoff_cnt) > 0) && |
173 | (__this_cpu_read(cmci_storm_state) == CMCI_STORM_ACTIVE)) { | |
174 | mce_notify_irq(); | |
175 | return CMCI_STORM_INTERVAL; | |
176 | } | |
55babd8f CG |
177 | |
178 | switch (__this_cpu_read(cmci_storm_state)) { | |
179 | case CMCI_STORM_ACTIVE: | |
3f2f0680 | 180 | |
55babd8f CG |
181 | /* |
182 | * We switch back to interrupt mode once the poll timer has | |
3f2f0680 BP |
183 | * silenced itself. That means no events recorded and the timer |
184 | * interval is back to our poll interval. | |
55babd8f CG |
185 | */ |
186 | __this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED); | |
3f2f0680 | 187 | if (!atomic_sub_return(1, &cmci_storm_on_cpus)) |
55babd8f | 188 | pr_notice("CMCI storm subsided: switching to interrupt mode\n"); |
3f2f0680 | 189 | |
55babd8f CG |
190 | /* FALLTHROUGH */ |
191 | ||
192 | case CMCI_STORM_SUBSIDED: | |
193 | /* | |
3f2f0680 BP |
194 | * We wait for all CPUs to go back to SUBSIDED state. When that |
195 | * happens we switch back to interrupt mode. | |
55babd8f CG |
196 | */ |
197 | if (!atomic_read(&cmci_storm_on_cpus)) { | |
198 | __this_cpu_write(cmci_storm_state, CMCI_STORM_NONE); | |
1b484655 | 199 | cmci_toggle_interrupt_mode(true); |
55babd8f CG |
200 | cmci_recheck(); |
201 | } | |
202 | return CMCI_POLL_INTERVAL; | |
203 | default: | |
3f2f0680 BP |
204 | |
205 | /* We have shiny weather. Let the poll do whatever it thinks. */ | |
55babd8f CG |
206 | return interval; |
207 | } | |
208 | } | |
209 | ||
210 | static bool cmci_storm_detect(void) | |
211 | { | |
212 | unsigned int cnt = __this_cpu_read(cmci_storm_cnt); | |
213 | unsigned long ts = __this_cpu_read(cmci_time_stamp); | |
214 | unsigned long now = jiffies; | |
215 | int r; | |
216 | ||
217 | if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE) | |
218 | return true; | |
219 | ||
220 | if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) { | |
221 | cnt++; | |
222 | } else { | |
223 | cnt = 1; | |
224 | __this_cpu_write(cmci_time_stamp, now); | |
225 | } | |
226 | __this_cpu_write(cmci_storm_cnt, cnt); | |
227 | ||
228 | if (cnt <= CMCI_STORM_THRESHOLD) | |
229 | return false; | |
230 | ||
1b484655 | 231 | cmci_toggle_interrupt_mode(false); |
55babd8f CG |
232 | __this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE); |
233 | r = atomic_add_return(1, &cmci_storm_on_cpus); | |
3f2f0680 BP |
234 | mce_timer_kick(CMCI_STORM_INTERVAL); |
235 | this_cpu_write(cmci_backoff_cnt, INITIAL_CHECK_INTERVAL); | |
55babd8f CG |
236 | |
237 | if (r == 1) | |
238 | pr_notice("CMCI storm detected: switching to poll mode\n"); | |
239 | return true; | |
240 | } | |
241 | ||
88ccbedd AK |
242 | /* |
243 | * The interrupt handler. This is called on every event. | |
244 | * Just call the poller directly to log any events. | |
245 | * This could in theory increase the threshold under high load, | |
246 | * but doesn't for now. | |
247 | */ | |
248 | static void intel_threshold_interrupt(void) | |
249 | { | |
55babd8f CG |
250 | if (cmci_storm_detect()) |
251 | return; | |
3f2f0680 | 252 | |
89cbc767 | 253 | machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned)); |
88ccbedd AK |
254 | } |
255 | ||
88ccbedd AK |
256 | /* |
257 | * Enable CMCI (Corrected Machine Check Interrupt) for available MCE banks | |
258 | * on this CPU. Use the algorithm recommended in the SDM to discover shared | |
259 | * banks. | |
260 | */ | |
4670a300 | 261 | static void cmci_discover(int banks) |
88ccbedd | 262 | { |
89cbc767 | 263 | unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned); |
e5299926 | 264 | unsigned long flags; |
88ccbedd | 265 | int i; |
450cc201 | 266 | int bios_wrong_thresh = 0; |
88ccbedd | 267 | |
ed5c41d3 | 268 | raw_spin_lock_irqsave(&cmci_discover_lock, flags); |
88ccbedd AK |
269 | for (i = 0; i < banks; i++) { |
270 | u64 val; | |
450cc201 | 271 | int bios_zero_thresh = 0; |
88ccbedd AK |
272 | |
273 | if (test_bit(i, owned)) | |
274 | continue; | |
275 | ||
c3d1fb56 NR |
276 | /* Skip banks in firmware first mode */ |
277 | if (test_bit(i, mce_banks_ce_disabled)) | |
278 | continue; | |
279 | ||
a2d32bcb | 280 | rdmsrl(MSR_IA32_MCx_CTL2(i), val); |
88ccbedd AK |
281 | |
282 | /* Already owned by someone else? */ | |
1f9a0bd4 | 283 | if (val & MCI_CTL2_CMCI_EN) { |
4670a300 | 284 | clear_bit(i, owned); |
89cbc767 | 285 | __clear_bit(i, this_cpu_ptr(mce_poll_banks)); |
88ccbedd AK |
286 | continue; |
287 | } | |
288 | ||
1462594b | 289 | if (!mca_cfg.bios_cmci_threshold) { |
450cc201 NR |
290 | val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK; |
291 | val |= CMCI_THRESHOLD; | |
292 | } else if (!(val & MCI_CTL2_CMCI_THRESHOLD_MASK)) { | |
293 | /* | |
294 | * If bios_cmci_threshold boot option was specified | |
295 | * but the threshold is zero, we'll try to initialize | |
296 | * it to 1. | |
297 | */ | |
298 | bios_zero_thresh = 1; | |
299 | val |= CMCI_THRESHOLD; | |
300 | } | |
301 | ||
302 | val |= MCI_CTL2_CMCI_EN; | |
a2d32bcb AK |
303 | wrmsrl(MSR_IA32_MCx_CTL2(i), val); |
304 | rdmsrl(MSR_IA32_MCx_CTL2(i), val); | |
88ccbedd AK |
305 | |
306 | /* Did the enable bit stick? -- the bank supports CMCI */ | |
1f9a0bd4 | 307 | if (val & MCI_CTL2_CMCI_EN) { |
4670a300 | 308 | set_bit(i, owned); |
89cbc767 | 309 | __clear_bit(i, this_cpu_ptr(mce_poll_banks)); |
450cc201 NR |
310 | /* |
311 | * We are able to set thresholds for some banks that | |
312 | * had a threshold of 0. This means the BIOS has not | |
313 | * set the thresholds properly or does not work with | |
314 | * this boot option. Note down now and report later. | |
315 | */ | |
1462594b | 316 | if (mca_cfg.bios_cmci_threshold && bios_zero_thresh && |
450cc201 NR |
317 | (val & MCI_CTL2_CMCI_THRESHOLD_MASK)) |
318 | bios_wrong_thresh = 1; | |
88ccbedd | 319 | } else { |
89cbc767 | 320 | WARN_ON(!test_bit(i, this_cpu_ptr(mce_poll_banks))); |
88ccbedd AK |
321 | } |
322 | } | |
ed5c41d3 | 323 | raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); |
1462594b | 324 | if (mca_cfg.bios_cmci_threshold && bios_wrong_thresh) { |
450cc201 NR |
325 | pr_info_once( |
326 | "bios_cmci_threshold: Some banks do not have valid thresholds set\n"); | |
327 | pr_info_once( | |
328 | "bios_cmci_threshold: Make sure your BIOS supports this boot option\n"); | |
329 | } | |
88ccbedd AK |
330 | } |
331 | ||
332 | /* | |
333 | * Just in case we missed an event during initialization check | |
334 | * all the CMCI owned banks. | |
335 | */ | |
df20e2eb | 336 | void cmci_recheck(void) |
88ccbedd AK |
337 | { |
338 | unsigned long flags; | |
339 | int banks; | |
340 | ||
89cbc767 | 341 | if (!mce_available(raw_cpu_ptr(&cpu_info)) || !cmci_supported(&banks)) |
88ccbedd | 342 | return; |
3f2f0680 | 343 | |
88ccbedd | 344 | local_irq_save(flags); |
89cbc767 | 345 | machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned)); |
88ccbedd AK |
346 | local_irq_restore(flags); |
347 | } | |
348 | ||
c3d1fb56 NR |
349 | /* Caller must hold the lock on cmci_discover_lock */ |
350 | static void __cmci_disable_bank(int bank) | |
351 | { | |
352 | u64 val; | |
353 | ||
89cbc767 | 354 | if (!test_bit(bank, this_cpu_ptr(mce_banks_owned))) |
c3d1fb56 NR |
355 | return; |
356 | rdmsrl(MSR_IA32_MCx_CTL2(bank), val); | |
357 | val &= ~MCI_CTL2_CMCI_EN; | |
358 | wrmsrl(MSR_IA32_MCx_CTL2(bank), val); | |
89cbc767 | 359 | __clear_bit(bank, this_cpu_ptr(mce_banks_owned)); |
c3d1fb56 NR |
360 | } |
361 | ||
88ccbedd AK |
362 | /* |
363 | * Disable CMCI on this CPU for all banks it owns when it goes down. | |
364 | * This allows other CPUs to claim the banks on rediscovery. | |
365 | */ | |
df20e2eb | 366 | void cmci_clear(void) |
88ccbedd | 367 | { |
e5299926 | 368 | unsigned long flags; |
88ccbedd AK |
369 | int i; |
370 | int banks; | |
88ccbedd AK |
371 | |
372 | if (!cmci_supported(&banks)) | |
373 | return; | |
ed5c41d3 | 374 | raw_spin_lock_irqsave(&cmci_discover_lock, flags); |
c3d1fb56 NR |
375 | for (i = 0; i < banks; i++) |
376 | __cmci_disable_bank(i); | |
ed5c41d3 | 377 | raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); |
88ccbedd AK |
378 | } |
379 | ||
7a0c819d | 380 | static void cmci_rediscover_work_func(void *arg) |
85b97637 TC |
381 | { |
382 | int banks; | |
383 | ||
384 | /* Recheck banks in case CPUs don't all have the same */ | |
385 | if (cmci_supported(&banks)) | |
386 | cmci_discover(banks); | |
85b97637 TC |
387 | } |
388 | ||
7a0c819d SB |
389 | /* After a CPU went down cycle through all the others and rediscover */ |
390 | void cmci_rediscover(void) | |
88ccbedd | 391 | { |
7a0c819d | 392 | int banks; |
88ccbedd AK |
393 | |
394 | if (!cmci_supported(&banks)) | |
395 | return; | |
88ccbedd | 396 | |
7a0c819d | 397 | on_each_cpu(cmci_rediscover_work_func, NULL, 1); |
88ccbedd AK |
398 | } |
399 | ||
400 | /* | |
401 | * Reenable CMCI on this CPU in case a CPU down failed. | |
402 | */ | |
403 | void cmci_reenable(void) | |
404 | { | |
405 | int banks; | |
406 | if (cmci_supported(&banks)) | |
4670a300 | 407 | cmci_discover(banks); |
88ccbedd AK |
408 | } |
409 | ||
c3d1fb56 NR |
410 | void cmci_disable_bank(int bank) |
411 | { | |
412 | int banks; | |
413 | unsigned long flags; | |
414 | ||
415 | if (!cmci_supported(&banks)) | |
416 | return; | |
417 | ||
ed5c41d3 | 418 | raw_spin_lock_irqsave(&cmci_discover_lock, flags); |
c3d1fb56 | 419 | __cmci_disable_bank(bank); |
ed5c41d3 | 420 | raw_spin_unlock_irqrestore(&cmci_discover_lock, flags); |
c3d1fb56 NR |
421 | } |
422 | ||
514ec49a | 423 | static void intel_init_cmci(void) |
88ccbedd AK |
424 | { |
425 | int banks; | |
426 | ||
427 | if (!cmci_supported(&banks)) | |
428 | return; | |
429 | ||
430 | mce_threshold_vector = intel_threshold_interrupt; | |
4670a300 | 431 | cmci_discover(banks); |
88ccbedd AK |
432 | /* |
433 | * For CPU #0 this runs with still disabled APIC, but that's | |
434 | * ok because only the vector is set up. We still do another | |
435 | * check for the banks later for CPU #0 just to make sure | |
436 | * to not miss any events. | |
437 | */ | |
438 | apic_write(APIC_LVTCMCI, THRESHOLD_APIC_VECTOR|APIC_DM_FIXED); | |
439 | cmci_recheck(); | |
440 | } | |
441 | ||
8838eb6c | 442 | static void intel_init_lmce(void) |
88d53867 AR |
443 | { |
444 | u64 val; | |
445 | ||
446 | if (!lmce_supported()) | |
447 | return; | |
448 | ||
449 | rdmsrl(MSR_IA32_MCG_EXT_CTL, val); | |
450 | ||
451 | if (!(val & MCG_EXT_CTL_LMCE_EN)) | |
452 | wrmsrl(MSR_IA32_MCG_EXT_CTL, val | MCG_EXT_CTL_LMCE_EN); | |
453 | } | |
454 | ||
8838eb6c AR |
455 | static void intel_clear_lmce(void) |
456 | { | |
457 | u64 val; | |
458 | ||
459 | if (!lmce_supported()) | |
460 | return; | |
461 | ||
462 | rdmsrl(MSR_IA32_MCG_EXT_CTL, val); | |
463 | val &= ~MCG_EXT_CTL_LMCE_EN; | |
464 | wrmsrl(MSR_IA32_MCG_EXT_CTL, val); | |
465 | } | |
466 | ||
cc3ca220 | 467 | void mce_intel_feature_init(struct cpuinfo_x86 *c) |
1da177e4 LT |
468 | { |
469 | intel_init_thermal(c); | |
88ccbedd | 470 | intel_init_cmci(); |
243d657e | 471 | intel_init_lmce(); |
1da177e4 | 472 | } |
8838eb6c AR |
473 | |
474 | void mce_intel_feature_clear(struct cpuinfo_x86 *c) | |
475 | { | |
476 | intel_clear_lmce(); | |
477 | } |