1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * (c) 2005-2016 Advanced Micro Devices, Inc.
4 *
5 * Written by Jacob Shin - AMD, Inc.
6 * Maintained by: Borislav Petkov <bp@alien8.de>
7 *
8 * All MC4_MISCi registers are shared between cores on a node.
9 */
10#include <linux/interrupt.h>
11#include <linux/notifier.h>
12#include <linux/kobject.h>
13#include <linux/percpu.h>
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/sysfs.h>
17#include <linux/slab.h>
18#include <linux/init.h>
19#include <linux/cpu.h>
20#include <linux/smp.h>
21#include <linux/string.h>
22
23#include <asm/amd_nb.h>
24#include <asm/traps.h>
25#include <asm/apic.h>
26#include <asm/mce.h>
27#include <asm/msr.h>
28#include <asm/trace/irq_vectors.h>
29
30#include "internal.h"
31
32#define NR_BLOCKS 5
33#define THRESHOLD_MAX 0xFFF
34#define INT_TYPE_APIC 0x00020000
35#define MASK_VALID_HI 0x80000000
36#define MASK_CNTP_HI 0x40000000
37#define MASK_LOCKED_HI 0x20000000
38#define MASK_LVTOFF_HI 0x00F00000
39#define MASK_COUNT_EN_HI 0x00080000
40#define MASK_INT_TYPE_HI 0x00060000
41#define MASK_OVERFLOW_HI 0x00010000
42#define MASK_ERR_COUNT_HI 0x00000FFF
43#define MASK_BLKPTR_LO 0xFF000000
44#define MCG_XBLK_ADDR 0xC0000400
45
46/* Deferred error settings */
47#define MSR_CU_DEF_ERR 0xC0000410
48#define MASK_DEF_LVTOFF 0x000000F0
49#define MASK_DEF_INT_TYPE 0x00000006
50#define DEF_LVT_OFF 0x2
51#define DEF_INT_TYPE_APIC 0x2
52
53/* Scalable MCA: */
54
55/* Threshold LVT offset is at MSR0xC0000410[15:12] */
56#define SMCA_THR_LVT_OFF 0xF000
57
58static bool thresholding_irq_en;
59
60static const char * const th_names[] = {
61 "load_store",
62 "insn_fetch",
63 "combined_unit",
64 "decode_unit",
65 "northbridge",
66 "execution_unit",
67};
68
69static const char * const smca_umc_block_names[] = {
70 "dram_ecc",
71 "misc_umc"
72};
73
74#define HWID_MCATYPE(hwid, mcatype) (((hwid) << 16) | (mcatype))
75
76struct smca_hwid {
77 unsigned int bank_type; /* Use with smca_bank_types for easy indexing. */
78 u32 hwid_mcatype; /* (hwid,mcatype) tuple */
79};
80
81struct smca_bank {
82 const struct smca_hwid *hwid;
83 u32 id; /* Value of MCA_IPID[InstanceId]. */
84 u8 sysfs_id; /* Value used for sysfs name. */
85};
86
87static DEFINE_PER_CPU_READ_MOSTLY(struct smca_bank[MAX_NR_BANKS], smca_banks);
88static DEFINE_PER_CPU_READ_MOSTLY(u8[N_SMCA_BANK_TYPES], smca_bank_counts);
89
90static const char * const smca_names[] = {
91 [SMCA_LS ... SMCA_LS_V2] = "load_store",
92 [SMCA_IF] = "insn_fetch",
93 [SMCA_L2_CACHE] = "l2_cache",
94 [SMCA_DE] = "decode_unit",
95 [SMCA_RESERVED] = "reserved",
96 [SMCA_EX] = "execution_unit",
97 [SMCA_FP] = "floating_point",
98 [SMCA_L3_CACHE] = "l3_cache",
99 [SMCA_CS ... SMCA_CS_V2] = "coherent_slave",
100 [SMCA_PIE] = "pie",
101
102 /* UMC v2 is separate because both of them can exist in a single system. */
103 [SMCA_UMC] = "umc",
104 [SMCA_UMC_V2] = "umc_v2",
105 [SMCA_MA_LLC] = "ma_llc",
106 [SMCA_PB] = "param_block",
107 [SMCA_PSP ... SMCA_PSP_V2] = "psp",
108 [SMCA_SMU ... SMCA_SMU_V2] = "smu",
109 [SMCA_MP5] = "mp5",
110 [SMCA_MPDMA] = "mpdma",
111 [SMCA_NBIO] = "nbio",
112 [SMCA_PCIE ... SMCA_PCIE_V2] = "pcie",
113 [SMCA_XGMI_PCS] = "xgmi_pcs",
114 [SMCA_NBIF] = "nbif",
115 [SMCA_SHUB] = "shub",
116 [SMCA_SATA] = "sata",
117 [SMCA_USB] = "usb",
118 [SMCA_USR_DP] = "usr_dp",
119 [SMCA_USR_CP] = "usr_cp",
120 [SMCA_GMI_PCS] = "gmi_pcs",
121 [SMCA_XGMI_PHY] = "xgmi_phy",
122 [SMCA_WAFL_PHY] = "wafl_phy",
123 [SMCA_GMI_PHY] = "gmi_phy",
124};
125
126static const char *smca_get_name(enum smca_bank_types t)
127{
128 if (t >= N_SMCA_BANK_TYPES)
129 return NULL;
130
131 return smca_names[t];
132}
133
134enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank)
135{
136 struct smca_bank *b;
137
138 if (bank >= MAX_NR_BANKS)
139 return N_SMCA_BANK_TYPES;
140
141 b = &per_cpu(smca_banks, cpu)[bank];
142 if (!b->hwid)
143 return N_SMCA_BANK_TYPES;
144
145 return b->hwid->bank_type;
146}
147EXPORT_SYMBOL_GPL(smca_get_bank_type);
148
149static const struct smca_hwid smca_hwid_mcatypes[] = {
150 /* { bank_type, hwid_mcatype } */
151
152 /* Reserved type */
153 { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0) },
154
155 /* ZN Core (HWID=0xB0) MCA types */
156 { SMCA_LS, HWID_MCATYPE(0xB0, 0x0) },
157 { SMCA_LS_V2, HWID_MCATYPE(0xB0, 0x10) },
158 { SMCA_IF, HWID_MCATYPE(0xB0, 0x1) },
159 { SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2) },
160 { SMCA_DE, HWID_MCATYPE(0xB0, 0x3) },
161 /* HWID 0xB0 MCATYPE 0x4 is Reserved */
162 { SMCA_EX, HWID_MCATYPE(0xB0, 0x5) },
163 { SMCA_FP, HWID_MCATYPE(0xB0, 0x6) },
164 { SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7) },
165
166 /* Data Fabric MCA types */
167 { SMCA_CS, HWID_MCATYPE(0x2E, 0x0) },
168 { SMCA_PIE, HWID_MCATYPE(0x2E, 0x1) },
169 { SMCA_CS_V2, HWID_MCATYPE(0x2E, 0x2) },
170 { SMCA_MA_LLC, HWID_MCATYPE(0x2E, 0x4) },
171
172 /* Unified Memory Controller MCA type */
173 { SMCA_UMC, HWID_MCATYPE(0x96, 0x0) },
174 { SMCA_UMC_V2, HWID_MCATYPE(0x96, 0x1) },
175
176 /* Parameter Block MCA type */
177 { SMCA_PB, HWID_MCATYPE(0x05, 0x0) },
178
179 /* Platform Security Processor MCA type */
180 { SMCA_PSP, HWID_MCATYPE(0xFF, 0x0) },
181 { SMCA_PSP_V2, HWID_MCATYPE(0xFF, 0x1) },
182
183 /* System Management Unit MCA type */
184 { SMCA_SMU, HWID_MCATYPE(0x01, 0x0) },
185 { SMCA_SMU_V2, HWID_MCATYPE(0x01, 0x1) },
186
187 /* Microprocessor 5 Unit MCA type */
188 { SMCA_MP5, HWID_MCATYPE(0x01, 0x2) },
189
190 /* MPDMA MCA type */
191 { SMCA_MPDMA, HWID_MCATYPE(0x01, 0x3) },
192
193 /* Northbridge IO Unit MCA type */
194 { SMCA_NBIO, HWID_MCATYPE(0x18, 0x0) },
195
196 /* PCI Express Unit MCA type */
197 { SMCA_PCIE, HWID_MCATYPE(0x46, 0x0) },
198 { SMCA_PCIE_V2, HWID_MCATYPE(0x46, 0x1) },
199
200 { SMCA_XGMI_PCS, HWID_MCATYPE(0x50, 0x0) },
201 { SMCA_NBIF, HWID_MCATYPE(0x6C, 0x0) },
202 { SMCA_SHUB, HWID_MCATYPE(0x80, 0x0) },
203 { SMCA_SATA, HWID_MCATYPE(0xA8, 0x0) },
204 { SMCA_USB, HWID_MCATYPE(0xAA, 0x0) },
205 { SMCA_USR_DP, HWID_MCATYPE(0x170, 0x0) },
206 { SMCA_USR_CP, HWID_MCATYPE(0x180, 0x0) },
207 { SMCA_GMI_PCS, HWID_MCATYPE(0x241, 0x0) },
208 { SMCA_XGMI_PHY, HWID_MCATYPE(0x259, 0x0) },
209 { SMCA_WAFL_PHY, HWID_MCATYPE(0x267, 0x0) },
210 { SMCA_GMI_PHY, HWID_MCATYPE(0x269, 0x0) },
211};
212
213/*
214 * In SMCA enabled processors, we can have multiple banks for a given IP type.
215 * So to define a unique name for each bank, we use a temp c-string to append
216 * the MCA_IPID[InstanceId] to type's name in get_name().
217 *
218 * InstanceId is 32 bits which is 8 characters. Make sure MAX_MCATYPE_NAME_LEN
219 * is greater than 8 plus 1 (for underscore) plus length of longest type name.
220 */
221#define MAX_MCATYPE_NAME_LEN 30
222static char buf_mcatype[MAX_MCATYPE_NAME_LEN];
223
224static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);
225
226/*
227 * A list of the banks enabled on each logical CPU. Controls which respective
228 * descriptors to initialize later in mce_threshold_create_device().
229 */
230static DEFINE_PER_CPU(u64, bank_map);
231
232/* Map of banks that have more than MCA_MISC0 available. */
233static DEFINE_PER_CPU(u64, smca_misc_banks_map);
234
235static void amd_threshold_interrupt(void);
236static void amd_deferred_error_interrupt(void);
237
238static void default_deferred_error_interrupt(void)
239{
240 pr_err("Unexpected deferred interrupt at vector %x\n", DEFERRED_ERROR_VECTOR);
241}
242void (*deferred_error_int_vector)(void) = default_deferred_error_interrupt;
243
244static void smca_set_misc_banks_map(unsigned int bank, unsigned int cpu)
245{
246 u32 low, high;
247
248 /*
249 * For SMCA enabled processors, BLKPTR field of the first MISC register
250 * (MCx_MISC0) indicates presence of additional MISC regs set (MISC1-4).
251 */
252 if (rdmsr_safe(MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high))
253 return;
254
255 if (!(low & MCI_CONFIG_MCAX))
256 return;
257
258 if (rdmsr_safe(MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high))
259 return;
260
261 if (low & MASK_BLKPTR_LO)
262 per_cpu(smca_misc_banks_map, cpu) |= BIT_ULL(bank);
263
264}
265
266static void smca_configure(unsigned int bank, unsigned int cpu)
267{
268 u8 *bank_counts = this_cpu_ptr(smca_bank_counts);
269 const struct smca_hwid *s_hwid;
270 unsigned int i, hwid_mcatype;
271 u32 high, low;
272 u32 smca_config = MSR_AMD64_SMCA_MCx_CONFIG(bank);
273
274 /* Set appropriate bits in MCA_CONFIG */
275 if (!rdmsr_safe(smca_config, &low, &high)) {
276 /*
277 * OS is required to set the MCAX bit to acknowledge that it is
278 * now using the new MSR ranges and new registers under each
279 * bank. It also means that the OS will configure deferred
280 * errors in the new MCx_CONFIG register. If the bit is not set,
281 * uncorrectable errors will cause a system panic.
282 *
283 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
284 */
285 high |= BIT(0);
286
287 /*
288 * SMCA sets the Deferred Error Interrupt type per bank.
289 *
290 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
291 * if the DeferredIntType bit field is available.
292 *
293 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
294 * high portion of the MSR). OS should set this to 0x1 to enable
295 * APIC based interrupt. First, check that no interrupt has been
296 * set.
297 */
298 if ((low & BIT(5)) && !((high >> 5) & 0x3))
299 high |= BIT(5);
300
301 this_cpu_ptr(mce_banks_array)[bank].lsb_in_status = !!(low & BIT(8));
302
303 wrmsr(smca_config, low, high);
304 }
305
306 smca_set_misc_banks_map(bank, cpu);
307
308 if (rdmsr_safe(MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
309 pr_warn("Failed to read MCA_IPID for bank %d\n", bank);
310 return;
311 }
312
313 hwid_mcatype = HWID_MCATYPE(high & MCI_IPID_HWID,
314 (high & MCI_IPID_MCATYPE) >> 16);
315
316 for (i = 0; i < ARRAY_SIZE(smca_hwid_mcatypes); i++) {
317 s_hwid = &smca_hwid_mcatypes[i];
318
319 if (hwid_mcatype == s_hwid->hwid_mcatype) {
320 this_cpu_ptr(smca_banks)[bank].hwid = s_hwid;
321 this_cpu_ptr(smca_banks)[bank].id = low;
322 this_cpu_ptr(smca_banks)[bank].sysfs_id = bank_counts[s_hwid->bank_type]++;
323 break;
324 }
325 }
326}
327
328struct thresh_restart {
329 struct threshold_block *b;
330 int reset;
331 int set_lvt_off;
332 int lvt_off;
333 u16 old_limit;
334};
335
336static inline bool is_shared_bank(int bank)
337{
338 /*
339 * Scalable MCA provides for only one core to have access to the MSRs of
340 * a shared bank.
341 */
342 if (mce_flags.smca)
343 return false;
344
345 /* Bank 4 is for northbridge reporting and is thus shared */
346 return (bank == 4);
347}
348
349static const char *bank4_names(const struct threshold_block *b)
350{
351 switch (b->address) {
352 /* MSR4_MISC0 */
353 case 0x00000413:
354 return "dram";
355
356 case 0xc0000408:
357 return "ht_links";
358
359 case 0xc0000409:
360 return "l3_cache";
361
362 default:
363 WARN(1, "Funny MSR: 0x%08x\n", b->address);
364 return "";
365 }
366};
367
368
369static bool lvt_interrupt_supported(unsigned int bank, u32 msr_high_bits)
370{
371 /*
372 * bank 4 supports APIC LVT interrupts implicitly since forever.
373 */
374 if (bank == 4)
375 return true;
376
377 /*
378 * IntP: interrupt present; if this bit is set, the thresholding
379 * bank can generate APIC LVT interrupts
380 */
381 return msr_high_bits & BIT(28);
382}
383
384static int lvt_off_valid(struct threshold_block *b, int apic, u32 lo, u32 hi)
385{
386 int msr = (hi & MASK_LVTOFF_HI) >> 20;
387
388 if (apic < 0) {
389 pr_err(FW_BUG "cpu %d, failed to setup threshold interrupt "
390 "for bank %d, block %d (MSR%08X=0x%x%08x)\n", b->cpu,
391 b->bank, b->block, b->address, hi, lo);
392 return 0;
393 }
394
395 if (apic != msr) {
396 /*
397 * On SMCA CPUs, LVT offset is programmed at a different MSR, and
398 * the BIOS provides the value. The original field where LVT offset
399 * was set is reserved. Return early here:
400 */
401 if (mce_flags.smca)
402 return 0;
403
404 pr_err(FW_BUG "cpu %d, invalid threshold interrupt offset %d "
405 "for bank %d, block %d (MSR%08X=0x%x%08x)\n",
406 b->cpu, apic, b->bank, b->block, b->address, hi, lo);
407 return 0;
408 }
409
410 return 1;
411};
412
413/* Reprogram MCx_MISC MSR behind this threshold bank. */
414static void threshold_restart_bank(void *_tr)
415{
416 struct thresh_restart *tr = _tr;
417 u32 hi, lo;
418
419 /* sysfs write might race against an offline operation */
420 if (!this_cpu_read(threshold_banks) && !tr->set_lvt_off)
421 return;
422
423 rdmsr(tr->b->address, lo, hi);
424
425 if (tr->b->threshold_limit < (hi & THRESHOLD_MAX))
426 tr->reset = 1; /* limit cannot be lower than err count */
427
428 if (tr->reset) { /* reset err count and overflow bit */
429 hi =
430 (hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) |
431 (THRESHOLD_MAX - tr->b->threshold_limit);
432 } else if (tr->old_limit) { /* change limit w/o reset */
433 int new_count = (hi & THRESHOLD_MAX) +
434 (tr->old_limit - tr->b->threshold_limit);
435
436 hi = (hi & ~MASK_ERR_COUNT_HI) |
437 (new_count & THRESHOLD_MAX);
438 }
439
440 /* clear IntType */
441 hi &= ~MASK_INT_TYPE_HI;
442
443 if (!tr->b->interrupt_capable)
444 goto done;
445
446 if (tr->set_lvt_off) {
447 if (lvt_off_valid(b: tr->b, apic: tr->lvt_off, lo, hi)) {
448 /* set new lvt offset */
449 hi &= ~MASK_LVTOFF_HI;
450 hi |= tr->lvt_off << 20;
451 }
452 }
453
454 if (tr->b->interrupt_enable)
455 hi |= INT_TYPE_APIC;
456
457 done:
458
459 hi |= MASK_COUNT_EN_HI;
460 wrmsr(tr->b->address, lo, hi);
461}
462
463static void mce_threshold_block_init(struct threshold_block *b, int offset)
464{
465 struct thresh_restart tr = {
466 .b = b,
467 .set_lvt_off = 1,
468 .lvt_off = offset,
469 };
470
471 b->threshold_limit = THRESHOLD_MAX;
472 threshold_restart_bank(tr: &tr);
473};
474
475static int setup_APIC_mce_threshold(int reserved, int new)
476{
477 if (reserved < 0 && !setup_APIC_eilvt(lvt_off: new, THRESHOLD_APIC_VECTOR,
478 APIC_EILVT_MSG_FIX, mask: 0))
479 return new;
480
481 return reserved;
482}
483
484static int setup_APIC_deferred_error(int reserved, int new)
485{
486 if (reserved < 0 && !setup_APIC_eilvt(lvt_off: new, DEFERRED_ERROR_VECTOR,
487 APIC_EILVT_MSG_FIX, mask: 0))
488 return new;
489
490 return reserved;
491}
492
493static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
494{
495 u32 low = 0, high = 0;
496 int def_offset = -1, def_new;
497
498 if (rdmsr_safe(MSR_CU_DEF_ERR, &low, &high))
499 return;
500
501 def_new = (low & MASK_DEF_LVTOFF) >> 4;
502 if (!(low & MASK_DEF_LVTOFF)) {
503 pr_err(FW_BUG "Your BIOS is not setting up LVT offset 0x2 for deferred error IRQs correctly.\n");
504 def_new = DEF_LVT_OFF;
505 low = (low & ~MASK_DEF_LVTOFF) | (DEF_LVT_OFF << 4);
506 }
507
508 def_offset = setup_APIC_deferred_error(reserved: def_offset, new: def_new);
509 if ((def_offset == def_new) &&
510 (deferred_error_int_vector != amd_deferred_error_interrupt))
511 deferred_error_int_vector = amd_deferred_error_interrupt;
512
513 if (!mce_flags.smca)
514 low = (low & ~MASK_DEF_INT_TYPE) | DEF_INT_TYPE_APIC;
515
516 wrmsr(MSR_CU_DEF_ERR, low, high);
517}
518
519static u32 smca_get_block_address(unsigned int bank, unsigned int block,
520 unsigned int cpu)
521{
522 if (!block)
523 return MSR_AMD64_SMCA_MCx_MISC(bank);
524
525 if (!(per_cpu(smca_misc_banks_map, cpu) & BIT_ULL(bank)))
526 return 0;
527
528 return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
529}
530
531static u32 get_block_address(u32 current_addr, u32 low, u32 high,
532 unsigned int bank, unsigned int block,
533 unsigned int cpu)
534{
535 u32 addr = 0, offset = 0;
536
537 if ((bank >= per_cpu(mce_num_banks, cpu)) || (block >= NR_BLOCKS))
538 return addr;
539
540 if (mce_flags.smca)
541 return smca_get_block_address(bank, block, cpu);
542
543 /* Fall back to method we used for older processors: */
544 switch (block) {
545 case 0:
546 addr = mca_msr_reg(bank, reg: MCA_MISC);
547 break;
548 case 1:
549 offset = ((low & MASK_BLKPTR_LO) >> 21);
550 if (offset)
551 addr = MCG_XBLK_ADDR + offset;
552 break;
553 default:
554 addr = ++current_addr;
555 }
556 return addr;
557}
558
559static int
560prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
561 int offset, u32 misc_high)
562{
563 unsigned int cpu = smp_processor_id();
564 u32 smca_low, smca_high;
565 struct threshold_block b;
566 int new;
567
568 if (!block)
569 per_cpu(bank_map, cpu) |= BIT_ULL(bank);
570
571 memset(&b, 0, sizeof(b));
572 b.cpu = cpu;
573 b.bank = bank;
574 b.block = block;
575 b.address = addr;
576 b.interrupt_capable = lvt_interrupt_supported(bank, msr_high_bits: misc_high);
577
578 if (!b.interrupt_capable)
579 goto done;
580
581 b.interrupt_enable = 1;
582
583 if (!mce_flags.smca) {
584 new = (misc_high & MASK_LVTOFF_HI) >> 20;
585 goto set_offset;
586 }
587
588 /* Gather LVT offset for thresholding: */
589 if (rdmsr_safe(MSR_CU_DEF_ERR, &smca_low, &smca_high))
590 goto out;
591
592 new = (smca_low & SMCA_THR_LVT_OFF) >> 12;
593
594set_offset:
595 offset = setup_APIC_mce_threshold(reserved: offset, new);
596 if (offset == new)
597 thresholding_irq_en = true;
598
599done:
600 mce_threshold_block_init(b: &b, offset);
601
602out:
603 return offset;
604}
605
606bool amd_filter_mce(struct mce *m)
607{
608 enum smca_bank_types bank_type = smca_get_bank_type(m->extcpu, m->bank);
609 struct cpuinfo_x86 *c = &boot_cpu_data;
610
611 /* See Family 17h Models 10h-2Fh Erratum #1114. */
612 if (c->x86 == 0x17 &&
613 c->x86_model >= 0x10 && c->x86_model <= 0x2F &&
614 bank_type == SMCA_IF && XEC(m->status, 0x3f) == 10)
615 return true;
616
617 /* NB GART TLB error reporting is disabled by default. */
618 if (c->x86 < 0x17) {
619 if (m->bank == 4 && XEC(m->status, 0x1f) == 0x5)
620 return true;
621 }
622
623 return false;
624}
625
626/*
627 * Turn off thresholding banks for the following conditions:
628 * - MC4_MISC thresholding is not supported on Family 0x15.
629 * - Prevent possible spurious interrupts from the IF bank on Family 0x17
630 * Models 0x10-0x2F due to Erratum #1114.
631 */
632static void disable_err_thresholding(struct cpuinfo_x86 *c, unsigned int bank)
633{
634 int i, num_msrs;
635 u64 hwcr;
636 bool need_toggle;
637 u32 msrs[NR_BLOCKS];
638
639 if (c->x86 == 0x15 && bank == 4) {
640 msrs[0] = 0x00000413; /* MC4_MISC0 */
641 msrs[1] = 0xc0000408; /* MC4_MISC1 */
642 num_msrs = 2;
643 } else if (c->x86 == 0x17 &&
644 (c->x86_model >= 0x10 && c->x86_model <= 0x2F)) {
645
646 if (smca_get_bank_type(smp_processor_id(), bank) != SMCA_IF)
647 return;
648
649 msrs[0] = MSR_AMD64_SMCA_MCx_MISC(bank);
650 num_msrs = 1;
651 } else {
652 return;
653 }
654
655 rdmsrl(MSR_K7_HWCR, hwcr);
656
657 /* McStatusWrEn has to be set */
658 need_toggle = !(hwcr & BIT(18));
659 if (need_toggle)
660 wrmsrl(MSR_K7_HWCR, val: hwcr | BIT(18));
661
662 /* Clear CntP bit safely */
663 for (i = 0; i < num_msrs; i++)
664 msr_clear_bit(msr: msrs[i], bit: 62);
665
666 /* restore old settings */
667 if (need_toggle)
668 wrmsrl(MSR_K7_HWCR, val: hwcr);
669}
670
671/* cpu init entry point, called from mce.c with preempt off */
672void mce_amd_feature_init(struct cpuinfo_x86 *c)
673{
674 unsigned int bank, block, cpu = smp_processor_id();
675 u32 low = 0, high = 0, address = 0;
676 int offset = -1;
677
678
679 for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
680 if (mce_flags.smca)
681 smca_configure(bank, cpu);
682
683 disable_err_thresholding(c, bank);
684
685 for (block = 0; block < NR_BLOCKS; ++block) {
686 address = get_block_address(current_addr: address, low, high, bank, block, cpu);
687 if (!address)
688 break;
689
690 if (rdmsr_safe(address, &low, &high))
691 break;
692
693 if (!(high & MASK_VALID_HI))
694 continue;
695
696 if (!(high & MASK_CNTP_HI) ||
697 (high & MASK_LOCKED_HI))
698 continue;
699
700 offset = prepare_threshold_block(bank, block, addr: address, offset, misc_high: high);
701 }
702 }
703
704 if (mce_flags.succor)
705 deferred_error_interrupt_enable(c);
706}
707
708/*
709 * DRAM ECC errors are reported in the Northbridge (bank 4) with
710 * Extended Error Code 8.
711 */
712static bool legacy_mce_is_memory_error(struct mce *m)
713{
714 return m->bank == 4 && XEC(m->status, 0x1f) == 8;
715}
716
717/*
718 * DRAM ECC errors are reported in Unified Memory Controllers with
719 * Extended Error Code 0.
720 */
721static bool smca_mce_is_memory_error(struct mce *m)
722{
723 enum smca_bank_types bank_type;
724
725 if (XEC(m->status, 0x3f))
726 return false;
727
728 bank_type = smca_get_bank_type(m->extcpu, m->bank);
729
730 return bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2;
731}
732
733bool amd_mce_is_memory_error(struct mce *m)
734{
735 if (mce_flags.smca)
736 return smca_mce_is_memory_error(m);
737 else
738 return legacy_mce_is_memory_error(m);
739}
740
741/*
742 * AMD systems do not have an explicit indicator that the value in MCA_ADDR is
743 * a system physical address. Therefore, individual cases need to be detected.
744 * Future cases and checks will be added as needed.
745 *
746 * 1) General case
747 * a) Assume address is not usable.
748 * 2) Poison errors
749 * a) Indicated by MCA_STATUS[43]: poison. Defined for all banks except legacy
750 * northbridge (bank 4).
751 * b) Refers to poison consumption in the core. Does not include "no action",
752 * "action optional", or "deferred" error severities.
753 * c) Will include a usable address so that immediate action can be taken.
754 * 3) Northbridge DRAM ECC errors
755 * a) Reported in legacy bank 4 with extended error code (XEC) 8.
756 * b) MCA_STATUS[43] is *not* defined as poison in legacy bank 4. Therefore,
757 * this bit should not be checked.
758 *
759 * NOTE: SMCA UMC memory errors fall into case #1.
760 */
761bool amd_mce_usable_address(struct mce *m)
762{
763 /* Check special northbridge case 3) first. */
764 if (!mce_flags.smca) {
765 if (legacy_mce_is_memory_error(m))
766 return true;
767 else if (m->bank == 4)
768 return false;
769 }
770
771 /* Check poison bit for all other bank types. */
772 if (m->status & MCI_STATUS_POISON)
773 return true;
774
775 /* Assume address is not usable for all others. */
776 return false;
777}
778
779static void __log_error(unsigned int bank, u64 status, u64 addr, u64 misc)
780{
781 struct mce m;
782
783 mce_setup(m: &m);
784
785 m.status = status;
786 m.misc = misc;
787 m.bank = bank;
788 m.tsc = rdtsc();
789
790 if (m.status & MCI_STATUS_ADDRV) {
791 m.addr = addr;
792
793 smca_extract_err_addr(m: &m);
794 }
795
796 if (mce_flags.smca) {
797 rdmsrl(MSR_AMD64_SMCA_MCx_IPID(bank), m.ipid);
798
799 if (m.status & MCI_STATUS_SYNDV)
800 rdmsrl(MSR_AMD64_SMCA_MCx_SYND(bank), m.synd);
801 }
802
803 mce_log(m: &m);
804}
805
806DEFINE_IDTENTRY_SYSVEC(sysvec_deferred_error)
807{
808 trace_deferred_error_apic_entry(DEFERRED_ERROR_VECTOR);
809 inc_irq_stat(irq_deferred_error_count);
810 deferred_error_int_vector();
811 trace_deferred_error_apic_exit(DEFERRED_ERROR_VECTOR);
812 apic_eoi();
813}
814
815/*
816 * Returns true if the logged error is deferred. False, otherwise.
817 */
818static inline bool
819_log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
820{
821 u64 status, addr = 0;
822
823 rdmsrl(msr_stat, status);
824 if (!(status & MCI_STATUS_VAL))
825 return false;
826
827 if (status & MCI_STATUS_ADDRV)
828 rdmsrl(msr_addr, addr);
829
830 __log_error(bank, status, addr, misc);
831
832 wrmsrl(msr: msr_stat, val: 0);
833
834 return status & MCI_STATUS_DEFERRED;
835}
836
837static bool _log_error_deferred(unsigned int bank, u32 misc)
838{
839 if (!_log_error_bank(bank, msr_stat: mca_msr_reg(bank, reg: MCA_STATUS),
840 msr_addr: mca_msr_reg(bank, reg: MCA_ADDR), misc))
841 return false;
842
843 /*
844 * Non-SMCA systems don't have MCA_DESTAT/MCA_DEADDR registers.
845 * Return true here to avoid accessing these registers.
846 */
847 if (!mce_flags.smca)
848 return true;
849
850 /* Clear MCA_DESTAT if the deferred error was logged from MCA_STATUS. */
851 wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), val: 0);
852 return true;
853}
854
855/*
856 * We have three scenarios for checking for Deferred errors:
857 *
858 * 1) Non-SMCA systems check MCA_STATUS and log error if found.
859 * 2) SMCA systems check MCA_STATUS. If error is found then log it and also
860 * clear MCA_DESTAT.
861 * 3) SMCA systems check MCA_DESTAT, if error was not found in MCA_STATUS, and
862 * log it.
863 */
864static void log_error_deferred(unsigned int bank)
865{
866 if (_log_error_deferred(bank, misc: 0))
867 return;
868
869 /*
870 * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check
871 * for a valid error.
872 */
873 _log_error_bank(bank, MSR_AMD64_SMCA_MCx_DESTAT(bank),
874 MSR_AMD64_SMCA_MCx_DEADDR(bank), misc: 0);
875}
876
877/* APIC interrupt handler for deferred errors */
878static void amd_deferred_error_interrupt(void)
879{
880 unsigned int bank;
881
882 for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank)
883 log_error_deferred(bank);
884}
885
886static void log_error_thresholding(unsigned int bank, u64 misc)
887{
888 _log_error_deferred(bank, misc);
889}
890
891static void log_and_reset_block(struct threshold_block *block)
892{
893 struct thresh_restart tr;
894 u32 low = 0, high = 0;
895
896 if (!block)
897 return;
898
899 if (rdmsr_safe(block->address, &low, &high))
900 return;
901
902 if (!(high & MASK_OVERFLOW_HI))
903 return;
904
905 /* Log the MCE which caused the threshold event. */
906 log_error_thresholding(bank: block->bank, misc: ((u64)high << 32) | low);
907
908 /* Reset threshold block after logging error. */
909 memset(&tr, 0, sizeof(tr));
910 tr.b = block;
911 threshold_restart_bank(tr: &tr);
912}
913
914/*
915 * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
916 * goes off when error_count reaches threshold_limit.
917 */
918static void amd_threshold_interrupt(void)
919{
920 struct threshold_block *first_block = NULL, *block = NULL, *tmp = NULL;
921 struct threshold_bank **bp = this_cpu_read(threshold_banks);
922 unsigned int bank, cpu = smp_processor_id();
923
924 /*
925 * Validate that the threshold bank has been initialized already. The
926 * handler is installed at boot time, but on a hotplug event the
927 * interrupt might fire before the data has been initialized.
928 */
929 if (!bp)
930 return;
931
932 for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
933 if (!(per_cpu(bank_map, cpu) & BIT_ULL(bank)))
934 continue;
935
936 first_block = bp[bank]->blocks;
937 if (!first_block)
938 continue;
939
940 /*
941 * The first block is also the head of the list. Check it first
942 * before iterating over the rest.
943 */
944 log_and_reset_block(block: first_block);
945 list_for_each_entry_safe(block, tmp, &first_block->miscj, miscj)
946 log_and_reset_block(block);
947 }
948}
949
950/*
951 * Sysfs Interface
952 */
953
954struct threshold_attr {
955 struct attribute attr;
956 ssize_t (*show) (struct threshold_block *, char *);
957 ssize_t (*store) (struct threshold_block *, const char *, size_t count);
958};
959
960#define SHOW_FIELDS(name) \
961static ssize_t show_ ## name(struct threshold_block *b, char *buf) \
962{ \
963 return sprintf(buf, "%lu\n", (unsigned long) b->name); \
964}
965SHOW_FIELDS(interrupt_enable)
966SHOW_FIELDS(threshold_limit)
967
968static ssize_t
969store_interrupt_enable(struct threshold_block *b, const char *buf, size_t size)
970{
971 struct thresh_restart tr;
972 unsigned long new;
973
974 if (!b->interrupt_capable)
975 return -EINVAL;
976
977 if (kstrtoul(s: buf, base: 0, res: &new) < 0)
978 return -EINVAL;
979
980 b->interrupt_enable = !!new;
981
982 memset(&tr, 0, sizeof(tr));
983 tr.b = b;
984
985 if (smp_call_function_single(cpuid: b->cpu, func: threshold_restart_bank, info: &tr, wait: 1))
986 return -ENODEV;
987
988 return size;
989}
990
991static ssize_t
992store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
993{
994 struct thresh_restart tr;
995 unsigned long new;
996
997 if (kstrtoul(s: buf, base: 0, res: &new) < 0)
998 return -EINVAL;
999
1000 if (new > THRESHOLD_MAX)
1001 new = THRESHOLD_MAX;
1002 if (new < 1)
1003 new = 1;
1004
1005 memset(&tr, 0, sizeof(tr));
1006 tr.old_limit = b->threshold_limit;
1007 b->threshold_limit = new;
1008 tr.b = b;
1009
1010 if (smp_call_function_single(cpuid: b->cpu, func: threshold_restart_bank, info: &tr, wait: 1))
1011 return -ENODEV;
1012
1013 return size;
1014}
1015
1016static ssize_t show_error_count(struct threshold_block *b, char *buf)
1017{
1018 u32 lo, hi;
1019
1020 /* CPU might be offline by now */
1021 if (rdmsr_on_cpu(cpu: b->cpu, msr_no: b->address, l: &lo, h: &hi))
1022 return -ENODEV;
1023
1024 return sprintf(buf, fmt: "%u\n", ((hi & THRESHOLD_MAX) -
1025 (THRESHOLD_MAX - b->threshold_limit)));
1026}
1027
1028static struct threshold_attr error_count = {
1029 .attr = {.name = __stringify(error_count), .mode = 0444 },
1030 .show = show_error_count,
1031};
1032
1033#define RW_ATTR(val) \
1034static struct threshold_attr val = { \
1035 .attr = {.name = __stringify(val), .mode = 0644 }, \
1036 .show = show_## val, \
1037 .store = store_## val, \
1038};
1039
1040RW_ATTR(interrupt_enable);
1041RW_ATTR(threshold_limit);
1042
1043static struct attribute *default_attrs[] = {
1044 &threshold_limit.attr,
1045 &error_count.attr,
1046 NULL, /* possibly interrupt_enable if supported, see below */
1047 NULL,
1048};
1049ATTRIBUTE_GROUPS(default);
1050
1051#define to_block(k) container_of(k, struct threshold_block, kobj)
1052#define to_attr(a) container_of(a, struct threshold_attr, attr)
1053
1054static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
1055{
1056 struct threshold_block *b = to_block(kobj);
1057 struct threshold_attr *a = to_attr(attr);
1058 ssize_t ret;
1059
1060 ret = a->show ? a->show(b, buf) : -EIO;
1061
1062 return ret;
1063}
1064
1065static ssize_t store(struct kobject *kobj, struct attribute *attr,
1066 const char *buf, size_t count)
1067{
1068 struct threshold_block *b = to_block(kobj);
1069 struct threshold_attr *a = to_attr(attr);
1070 ssize_t ret;
1071
1072 ret = a->store ? a->store(b, buf, count) : -EIO;
1073
1074 return ret;
1075}
1076
1077static const struct sysfs_ops threshold_ops = {
1078 .show = show,
1079 .store = store,
1080};
1081
1082static void threshold_block_release(struct kobject *kobj);
1083
1084static const struct kobj_type threshold_ktype = {
1085 .sysfs_ops = &threshold_ops,
1086 .default_groups = default_groups,
1087 .release = threshold_block_release,
1088};
1089
1090static const char *get_name(unsigned int cpu, unsigned int bank, struct threshold_block *b)
1091{
1092 enum smca_bank_types bank_type;
1093
1094 if (!mce_flags.smca) {
1095 if (b && bank == 4)
1096 return bank4_names(b);
1097
1098 return th_names[bank];
1099 }
1100
1101 bank_type = smca_get_bank_type(cpu, bank);
1102 if (bank_type >= N_SMCA_BANK_TYPES)
1103 return NULL;
1104
1105 if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
1106 if (b->block < ARRAY_SIZE(smca_umc_block_names))
1107 return smca_umc_block_names[b->block];
1108 return NULL;
1109 }
1110
1111 if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
1112 return smca_get_name(t: bank_type);
1113
1114 snprintf(buf: buf_mcatype, MAX_MCATYPE_NAME_LEN,
1115 fmt: "%s_%u", smca_get_name(t: bank_type),
1116 per_cpu(smca_banks, cpu)[bank].sysfs_id);
1117 return buf_mcatype;
1118}
1119
1120static int allocate_threshold_blocks(unsigned int cpu, struct threshold_bank *tb,
1121 unsigned int bank, unsigned int block,
1122 u32 address)
1123{
1124 struct threshold_block *b = NULL;
1125 u32 low, high;
1126 int err;
1127
1128 if ((bank >= this_cpu_read(mce_num_banks)) || (block >= NR_BLOCKS))
1129 return 0;
1130
1131 if (rdmsr_safe(address, &low, &high))
1132 return 0;
1133
1134 if (!(high & MASK_VALID_HI)) {
1135 if (block)
1136 goto recurse;
1137 else
1138 return 0;
1139 }
1140
1141 if (!(high & MASK_CNTP_HI) ||
1142 (high & MASK_LOCKED_HI))
1143 goto recurse;
1144
1145 b = kzalloc(size: sizeof(struct threshold_block), GFP_KERNEL);
1146 if (!b)
1147 return -ENOMEM;
1148
1149 b->block = block;
1150 b->bank = bank;
1151 b->cpu = cpu;
1152 b->address = address;
1153 b->interrupt_enable = 0;
1154 b->interrupt_capable = lvt_interrupt_supported(bank, msr_high_bits: high);
1155 b->threshold_limit = THRESHOLD_MAX;
1156
1157 if (b->interrupt_capable) {
1158 default_attrs[2] = &interrupt_enable.attr;
1159 b->interrupt_enable = 1;
1160 } else {
1161 default_attrs[2] = NULL;
1162 }
1163
1164 INIT_LIST_HEAD(list: &b->miscj);
1165
1166 /* This is safe as @tb is not visible yet */
1167 if (tb->blocks)
1168 list_add(new: &b->miscj, head: &tb->blocks->miscj);
1169 else
1170 tb->blocks = b;
1171
1172 err = kobject_init_and_add(kobj: &b->kobj, ktype: &threshold_ktype, parent: tb->kobj, fmt: get_name(cpu, bank, b));
1173 if (err)
1174 goto out_free;
1175recurse:
1176 address = get_block_address(current_addr: address, low, high, bank, block: ++block, cpu);
1177 if (!address)
1178 return 0;
1179
1180 err = allocate_threshold_blocks(cpu, tb, bank, block, address);
1181 if (err)
1182 goto out_free;
1183
1184 if (b)
1185 kobject_uevent(kobj: &b->kobj, action: KOBJ_ADD);
1186
1187 return 0;
1188
1189out_free:
1190 if (b) {
1191 list_del(entry: &b->miscj);
1192 kobject_put(kobj: &b->kobj);
1193 }
1194 return err;
1195}
1196
1197static int __threshold_add_blocks(struct threshold_bank *b)
1198{
1199 struct list_head *head = &b->blocks->miscj;
1200 struct threshold_block *pos = NULL;
1201 struct threshold_block *tmp = NULL;
1202 int err = 0;
1203
1204 err = kobject_add(kobj: &b->blocks->kobj, parent: b->kobj, fmt: b->blocks->kobj.name);
1205 if (err)
1206 return err;
1207
1208 list_for_each_entry_safe(pos, tmp, head, miscj) {
1209
1210 err = kobject_add(kobj: &pos->kobj, parent: b->kobj, fmt: pos->kobj.name);
1211 if (err) {
1212 list_for_each_entry_safe_reverse(pos, tmp, head, miscj)
1213 kobject_del(kobj: &pos->kobj);
1214
1215 return err;
1216 }
1217 }
1218 return err;
1219}
1220
1221static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
1222 unsigned int bank)
1223{
1224 struct device *dev = this_cpu_read(mce_device);
1225 struct amd_northbridge *nb = NULL;
1226 struct threshold_bank *b = NULL;
1227 const char *name = get_name(cpu, bank, NULL);
1228 int err = 0;
1229
1230 if (!dev)
1231 return -ENODEV;
1232
1233 if (is_shared_bank(bank)) {
1234 nb = node_to_amd_nb(topology_amd_node_id(cpu));
1235
1236 /* threshold descriptor already initialized on this node? */
1237 if (nb && nb->bank4) {
1238 /* yes, use it */
1239 b = nb->bank4;
1240 err = kobject_add(kobj: b->kobj, parent: &dev->kobj, fmt: name);
1241 if (err)
1242 goto out;
1243
1244 bp[bank] = b;
1245 refcount_inc(r: &b->cpus);
1246
1247 err = __threshold_add_blocks(b);
1248
1249 goto out;
1250 }
1251 }
1252
1253 b = kzalloc(size: sizeof(struct threshold_bank), GFP_KERNEL);
1254 if (!b) {
1255 err = -ENOMEM;
1256 goto out;
1257 }
1258
1259 /* Associate the bank with the per-CPU MCE device */
1260 b->kobj = kobject_create_and_add(name, parent: &dev->kobj);
1261 if (!b->kobj) {
1262 err = -EINVAL;
1263 goto out_free;
1264 }
1265
1266 if (is_shared_bank(bank)) {
1267 b->shared = 1;
1268 refcount_set(r: &b->cpus, n: 1);
1269
1270 /* nb is already initialized, see above */
1271 if (nb) {
1272 WARN_ON(nb->bank4);
1273 nb->bank4 = b;
1274 }
1275 }
1276
1277 err = allocate_threshold_blocks(cpu, tb: b, bank, block: 0, address: mca_msr_reg(bank, reg: MCA_MISC));
1278 if (err)
1279 goto out_kobj;
1280
1281 bp[bank] = b;
1282 return 0;
1283
1284out_kobj:
1285 kobject_put(kobj: b->kobj);
1286out_free:
1287 kfree(objp: b);
1288out:
1289 return err;
1290}
1291
1292static void threshold_block_release(struct kobject *kobj)
1293{
1294 kfree(to_block(kobj));
1295}
1296
1297static void deallocate_threshold_blocks(struct threshold_bank *bank)
1298{
1299 struct threshold_block *pos, *tmp;
1300
1301 list_for_each_entry_safe(pos, tmp, &bank->blocks->miscj, miscj) {
1302 list_del(entry: &pos->miscj);
1303 kobject_put(kobj: &pos->kobj);
1304 }
1305
1306 kobject_put(kobj: &bank->blocks->kobj);
1307}
1308
1309static void __threshold_remove_blocks(struct threshold_bank *b)
1310{
1311 struct threshold_block *pos = NULL;
1312 struct threshold_block *tmp = NULL;
1313
1314 kobject_put(kobj: b->kobj);
1315
1316 list_for_each_entry_safe(pos, tmp, &b->blocks->miscj, miscj)
1317 kobject_put(kobj: b->kobj);
1318}
1319
1320static void threshold_remove_bank(struct threshold_bank *bank)
1321{
1322 struct amd_northbridge *nb;
1323
1324 if (!bank->blocks)
1325 goto out_free;
1326
1327 if (!bank->shared)
1328 goto out_dealloc;
1329
1330 if (!refcount_dec_and_test(r: &bank->cpus)) {
1331 __threshold_remove_blocks(b: bank);
1332 return;
1333 } else {
1334 /*
1335 * The last CPU on this node using the shared bank is going
1336 * away, remove that bank now.
1337 */
1338 nb = node_to_amd_nb(topology_amd_node_id(smp_processor_id()));
1339 nb->bank4 = NULL;
1340 }
1341
1342out_dealloc:
1343 deallocate_threshold_blocks(bank);
1344
1345out_free:
1346 kobject_put(kobj: bank->kobj);
1347 kfree(objp: bank);
1348}
1349
1350static void __threshold_remove_device(struct threshold_bank **bp)
1351{
1352 unsigned int bank, numbanks = this_cpu_read(mce_num_banks);
1353
1354 for (bank = 0; bank < numbanks; bank++) {
1355 if (!bp[bank])
1356 continue;
1357
1358 threshold_remove_bank(bank: bp[bank]);
1359 bp[bank] = NULL;
1360 }
1361 kfree(objp: bp);
1362}
1363
1364int mce_threshold_remove_device(unsigned int cpu)
1365{
1366 struct threshold_bank **bp = this_cpu_read(threshold_banks);
1367
1368 if (!bp)
1369 return 0;
1370
1371 /*
1372 * Clear the pointer before cleaning up, so that the interrupt won't
1373 * touch anything of this.
1374 */
1375 this_cpu_write(threshold_banks, NULL);
1376
1377 __threshold_remove_device(bp);
1378 return 0;
1379}
1380
1381/**
1382 * mce_threshold_create_device - Create the per-CPU MCE threshold device
1383 * @cpu: The plugged in CPU
1384 *
1385 * Create directories and files for all valid threshold banks.
1386 *
1387 * This is invoked from the CPU hotplug callback which was installed in
1388 * mcheck_init_device(). The invocation happens in context of the hotplug
1389 * thread running on @cpu. The callback is invoked on all CPUs which are
1390 * online when the callback is installed or during a real hotplug event.
1391 */
1392int mce_threshold_create_device(unsigned int cpu)
1393{
1394 unsigned int numbanks, bank;
1395 struct threshold_bank **bp;
1396 int err;
1397
1398 if (!mce_flags.amd_threshold)
1399 return 0;
1400
1401 bp = this_cpu_read(threshold_banks);
1402 if (bp)
1403 return 0;
1404
1405 numbanks = this_cpu_read(mce_num_banks);
1406 bp = kcalloc(n: numbanks, size: sizeof(*bp), GFP_KERNEL);
1407 if (!bp)
1408 return -ENOMEM;
1409
1410 for (bank = 0; bank < numbanks; ++bank) {
1411 if (!(this_cpu_read(bank_map) & BIT_ULL(bank)))
1412 continue;
1413 err = threshold_create_bank(bp, cpu, bank);
1414 if (err) {
1415 __threshold_remove_device(bp);
1416 return err;
1417 }
1418 }
1419 this_cpu_write(threshold_banks, bp);
1420
1421 if (thresholding_irq_en)
1422 mce_threshold_vector = amd_threshold_interrupt;
1423 return 0;
1424}
1425

source code of linux/arch/x86/kernel/cpu/mce/amd.c