xref: /openbmc/linux/arch/x86/kernel/cpu/mce/amd.c (revision 5176a93a)
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 
58 static bool thresholding_irq_en;
59 
60 static const char * const th_names[] = {
61 	"load_store",
62 	"insn_fetch",
63 	"combined_unit",
64 	"decode_unit",
65 	"northbridge",
66 	"execution_unit",
67 };
68 
69 static const char * const smca_umc_block_names[] = {
70 	"dram_ecc",
71 	"misc_umc"
72 };
73 
74 struct smca_bank_name {
75 	const char *name;	/* Short name for sysfs */
76 	const char *long_name;	/* Long name for pretty-printing */
77 };
78 
79 static struct smca_bank_name smca_names[] = {
80 	[SMCA_LS ... SMCA_LS_V2]	= { "load_store",	"Load Store Unit" },
81 	[SMCA_IF]			= { "insn_fetch",	"Instruction Fetch Unit" },
82 	[SMCA_L2_CACHE]			= { "l2_cache",		"L2 Cache" },
83 	[SMCA_DE]			= { "decode_unit",	"Decode Unit" },
84 	[SMCA_RESERVED]			= { "reserved",		"Reserved" },
85 	[SMCA_EX]			= { "execution_unit",	"Execution Unit" },
86 	[SMCA_FP]			= { "floating_point",	"Floating Point Unit" },
87 	[SMCA_L3_CACHE]			= { "l3_cache",		"L3 Cache" },
88 	[SMCA_CS ... SMCA_CS_V2]	= { "coherent_slave",	"Coherent Slave" },
89 	[SMCA_PIE]			= { "pie",		"Power, Interrupts, etc." },
90 
91 	/* UMC v2 is separate because both of them can exist in a single system. */
92 	[SMCA_UMC]			= { "umc",		"Unified Memory Controller" },
93 	[SMCA_UMC_V2]			= { "umc_v2",		"Unified Memory Controller v2" },
94 	[SMCA_PB]			= { "param_block",	"Parameter Block" },
95 	[SMCA_PSP ... SMCA_PSP_V2]	= { "psp",		"Platform Security Processor" },
96 	[SMCA_SMU ... SMCA_SMU_V2]	= { "smu",		"System Management Unit" },
97 	[SMCA_MP5]			= { "mp5",		"Microprocessor 5 Unit" },
98 	[SMCA_MPDMA]			= { "mpdma",		"MPDMA Unit" },
99 	[SMCA_NBIO]			= { "nbio",		"Northbridge IO Unit" },
100 	[SMCA_PCIE ... SMCA_PCIE_V2]	= { "pcie",		"PCI Express Unit" },
101 	[SMCA_XGMI_PCS]			= { "xgmi_pcs",		"Ext Global Memory Interconnect PCS Unit" },
102 	[SMCA_NBIF]			= { "nbif",		"NBIF Unit" },
103 	[SMCA_SHUB]			= { "shub",		"System Hub Unit" },
104 	[SMCA_SATA]			= { "sata",		"SATA Unit" },
105 	[SMCA_USB]			= { "usb",		"USB Unit" },
106 	[SMCA_GMI_PCS]			= { "gmi_pcs",		"Global Memory Interconnect PCS Unit" },
107 	[SMCA_XGMI_PHY]			= { "xgmi_phy",		"Ext Global Memory Interconnect PHY Unit" },
108 	[SMCA_WAFL_PHY]			= { "wafl_phy",		"WAFL PHY Unit" },
109 	[SMCA_GMI_PHY]			= { "gmi_phy",		"Global Memory Interconnect PHY Unit" },
110 };
111 
112 static const char *smca_get_name(enum smca_bank_types t)
113 {
114 	if (t >= N_SMCA_BANK_TYPES)
115 		return NULL;
116 
117 	return smca_names[t].name;
118 }
119 
120 const char *smca_get_long_name(enum smca_bank_types t)
121 {
122 	if (t >= N_SMCA_BANK_TYPES)
123 		return NULL;
124 
125 	return smca_names[t].long_name;
126 }
127 EXPORT_SYMBOL_GPL(smca_get_long_name);
128 
129 enum smca_bank_types smca_get_bank_type(unsigned int bank)
130 {
131 	struct smca_bank *b;
132 
133 	if (bank >= MAX_NR_BANKS)
134 		return N_SMCA_BANK_TYPES;
135 
136 	b = &smca_banks[bank];
137 	if (!b->hwid)
138 		return N_SMCA_BANK_TYPES;
139 
140 	return b->hwid->bank_type;
141 }
142 EXPORT_SYMBOL_GPL(smca_get_bank_type);
143 
144 static struct smca_hwid smca_hwid_mcatypes[] = {
145 	/* { bank_type, hwid_mcatype } */
146 
147 	/* Reserved type */
148 	{ SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0)	},
149 
150 	/* ZN Core (HWID=0xB0) MCA types */
151 	{ SMCA_LS,	 HWID_MCATYPE(0xB0, 0x0)	},
152 	{ SMCA_LS_V2,	 HWID_MCATYPE(0xB0, 0x10)	},
153 	{ SMCA_IF,	 HWID_MCATYPE(0xB0, 0x1)	},
154 	{ SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2)	},
155 	{ SMCA_DE,	 HWID_MCATYPE(0xB0, 0x3)	},
156 	/* HWID 0xB0 MCATYPE 0x4 is Reserved */
157 	{ SMCA_EX,	 HWID_MCATYPE(0xB0, 0x5)	},
158 	{ SMCA_FP,	 HWID_MCATYPE(0xB0, 0x6)	},
159 	{ SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7)	},
160 
161 	/* Data Fabric MCA types */
162 	{ SMCA_CS,	 HWID_MCATYPE(0x2E, 0x0)	},
163 	{ SMCA_PIE,	 HWID_MCATYPE(0x2E, 0x1)	},
164 	{ SMCA_CS_V2,	 HWID_MCATYPE(0x2E, 0x2)	},
165 
166 	/* Unified Memory Controller MCA type */
167 	{ SMCA_UMC,	 HWID_MCATYPE(0x96, 0x0)	},
168 	{ SMCA_UMC_V2,	 HWID_MCATYPE(0x96, 0x1)	},
169 
170 	/* Parameter Block MCA type */
171 	{ SMCA_PB,	 HWID_MCATYPE(0x05, 0x0)	},
172 
173 	/* Platform Security Processor MCA type */
174 	{ SMCA_PSP,	 HWID_MCATYPE(0xFF, 0x0)	},
175 	{ SMCA_PSP_V2,	 HWID_MCATYPE(0xFF, 0x1)	},
176 
177 	/* System Management Unit MCA type */
178 	{ SMCA_SMU,	 HWID_MCATYPE(0x01, 0x0)	},
179 	{ SMCA_SMU_V2,	 HWID_MCATYPE(0x01, 0x1)	},
180 
181 	/* Microprocessor 5 Unit MCA type */
182 	{ SMCA_MP5,	 HWID_MCATYPE(0x01, 0x2)	},
183 
184 	/* MPDMA MCA type */
185 	{ SMCA_MPDMA,	 HWID_MCATYPE(0x01, 0x3)	},
186 
187 	/* Northbridge IO Unit MCA type */
188 	{ SMCA_NBIO,	 HWID_MCATYPE(0x18, 0x0)	},
189 
190 	/* PCI Express Unit MCA type */
191 	{ SMCA_PCIE,	 HWID_MCATYPE(0x46, 0x0)	},
192 	{ SMCA_PCIE_V2,	 HWID_MCATYPE(0x46, 0x1)	},
193 
194 	{ SMCA_XGMI_PCS, HWID_MCATYPE(0x50, 0x0)	},
195 	{ SMCA_NBIF,	 HWID_MCATYPE(0x6C, 0x0)	},
196 	{ SMCA_SHUB,	 HWID_MCATYPE(0x80, 0x0)	},
197 	{ SMCA_SATA,	 HWID_MCATYPE(0xA8, 0x0)	},
198 	{ SMCA_USB,	 HWID_MCATYPE(0xAA, 0x0)	},
199 	{ SMCA_GMI_PCS,  HWID_MCATYPE(0x241, 0x0)	},
200 	{ SMCA_XGMI_PHY, HWID_MCATYPE(0x259, 0x0)	},
201 	{ SMCA_WAFL_PHY, HWID_MCATYPE(0x267, 0x0)	},
202 	{ SMCA_GMI_PHY,	 HWID_MCATYPE(0x269, 0x0)	},
203 };
204 
205 struct smca_bank smca_banks[MAX_NR_BANKS];
206 EXPORT_SYMBOL_GPL(smca_banks);
207 
208 /*
209  * In SMCA enabled processors, we can have multiple banks for a given IP type.
210  * So to define a unique name for each bank, we use a temp c-string to append
211  * the MCA_IPID[InstanceId] to type's name in get_name().
212  *
213  * InstanceId is 32 bits which is 8 characters. Make sure MAX_MCATYPE_NAME_LEN
214  * is greater than 8 plus 1 (for underscore) plus length of longest type name.
215  */
216 #define MAX_MCATYPE_NAME_LEN	30
217 static char buf_mcatype[MAX_MCATYPE_NAME_LEN];
218 
219 static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);
220 
221 /*
222  * A list of the banks enabled on each logical CPU. Controls which respective
223  * descriptors to initialize later in mce_threshold_create_device().
224  */
225 static DEFINE_PER_CPU(unsigned int, bank_map);
226 
227 /* Map of banks that have more than MCA_MISC0 available. */
228 static DEFINE_PER_CPU(u32, smca_misc_banks_map);
229 
230 static void amd_threshold_interrupt(void);
231 static void amd_deferred_error_interrupt(void);
232 
233 static void default_deferred_error_interrupt(void)
234 {
235 	pr_err("Unexpected deferred interrupt at vector %x\n", DEFERRED_ERROR_VECTOR);
236 }
237 void (*deferred_error_int_vector)(void) = default_deferred_error_interrupt;
238 
239 static void smca_set_misc_banks_map(unsigned int bank, unsigned int cpu)
240 {
241 	u32 low, high;
242 
243 	/*
244 	 * For SMCA enabled processors, BLKPTR field of the first MISC register
245 	 * (MCx_MISC0) indicates presence of additional MISC regs set (MISC1-4).
246 	 */
247 	if (rdmsr_safe(MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high))
248 		return;
249 
250 	if (!(low & MCI_CONFIG_MCAX))
251 		return;
252 
253 	if (rdmsr_safe(MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high))
254 		return;
255 
256 	if (low & MASK_BLKPTR_LO)
257 		per_cpu(smca_misc_banks_map, cpu) |= BIT(bank);
258 
259 }
260 
261 static void smca_configure(unsigned int bank, unsigned int cpu)
262 {
263 	unsigned int i, hwid_mcatype;
264 	struct smca_hwid *s_hwid;
265 	u32 high, low;
266 	u32 smca_config = MSR_AMD64_SMCA_MCx_CONFIG(bank);
267 
268 	/* Set appropriate bits in MCA_CONFIG */
269 	if (!rdmsr_safe(smca_config, &low, &high)) {
270 		/*
271 		 * OS is required to set the MCAX bit to acknowledge that it is
272 		 * now using the new MSR ranges and new registers under each
273 		 * bank. It also means that the OS will configure deferred
274 		 * errors in the new MCx_CONFIG register. If the bit is not set,
275 		 * uncorrectable errors will cause a system panic.
276 		 *
277 		 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
278 		 */
279 		high |= BIT(0);
280 
281 		/*
282 		 * SMCA sets the Deferred Error Interrupt type per bank.
283 		 *
284 		 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
285 		 * if the DeferredIntType bit field is available.
286 		 *
287 		 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
288 		 * high portion of the MSR). OS should set this to 0x1 to enable
289 		 * APIC based interrupt. First, check that no interrupt has been
290 		 * set.
291 		 */
292 		if ((low & BIT(5)) && !((high >> 5) & 0x3))
293 			high |= BIT(5);
294 
295 		wrmsr(smca_config, low, high);
296 	}
297 
298 	smca_set_misc_banks_map(bank, cpu);
299 
300 	/* Return early if this bank was already initialized. */
301 	if (smca_banks[bank].hwid && smca_banks[bank].hwid->hwid_mcatype != 0)
302 		return;
303 
304 	if (rdmsr_safe(MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
305 		pr_warn("Failed to read MCA_IPID for bank %d\n", bank);
306 		return;
307 	}
308 
309 	hwid_mcatype = HWID_MCATYPE(high & MCI_IPID_HWID,
310 				    (high & MCI_IPID_MCATYPE) >> 16);
311 
312 	for (i = 0; i < ARRAY_SIZE(smca_hwid_mcatypes); i++) {
313 		s_hwid = &smca_hwid_mcatypes[i];
314 		if (hwid_mcatype == s_hwid->hwid_mcatype) {
315 			smca_banks[bank].hwid = s_hwid;
316 			smca_banks[bank].id = low;
317 			smca_banks[bank].sysfs_id = s_hwid->count++;
318 			break;
319 		}
320 	}
321 }
322 
323 struct thresh_restart {
324 	struct threshold_block	*b;
325 	int			reset;
326 	int			set_lvt_off;
327 	int			lvt_off;
328 	u16			old_limit;
329 };
330 
331 static inline bool is_shared_bank(int bank)
332 {
333 	/*
334 	 * Scalable MCA provides for only one core to have access to the MSRs of
335 	 * a shared bank.
336 	 */
337 	if (mce_flags.smca)
338 		return false;
339 
340 	/* Bank 4 is for northbridge reporting and is thus shared */
341 	return (bank == 4);
342 }
343 
344 static const char *bank4_names(const struct threshold_block *b)
345 {
346 	switch (b->address) {
347 	/* MSR4_MISC0 */
348 	case 0x00000413:
349 		return "dram";
350 
351 	case 0xc0000408:
352 		return "ht_links";
353 
354 	case 0xc0000409:
355 		return "l3_cache";
356 
357 	default:
358 		WARN(1, "Funny MSR: 0x%08x\n", b->address);
359 		return "";
360 	}
361 };
362 
363 
364 static bool lvt_interrupt_supported(unsigned int bank, u32 msr_high_bits)
365 {
366 	/*
367 	 * bank 4 supports APIC LVT interrupts implicitly since forever.
368 	 */
369 	if (bank == 4)
370 		return true;
371 
372 	/*
373 	 * IntP: interrupt present; if this bit is set, the thresholding
374 	 * bank can generate APIC LVT interrupts
375 	 */
376 	return msr_high_bits & BIT(28);
377 }
378 
379 static int lvt_off_valid(struct threshold_block *b, int apic, u32 lo, u32 hi)
380 {
381 	int msr = (hi & MASK_LVTOFF_HI) >> 20;
382 
383 	if (apic < 0) {
384 		pr_err(FW_BUG "cpu %d, failed to setup threshold interrupt "
385 		       "for bank %d, block %d (MSR%08X=0x%x%08x)\n", b->cpu,
386 		       b->bank, b->block, b->address, hi, lo);
387 		return 0;
388 	}
389 
390 	if (apic != msr) {
391 		/*
392 		 * On SMCA CPUs, LVT offset is programmed at a different MSR, and
393 		 * the BIOS provides the value. The original field where LVT offset
394 		 * was set is reserved. Return early here:
395 		 */
396 		if (mce_flags.smca)
397 			return 0;
398 
399 		pr_err(FW_BUG "cpu %d, invalid threshold interrupt offset %d "
400 		       "for bank %d, block %d (MSR%08X=0x%x%08x)\n",
401 		       b->cpu, apic, b->bank, b->block, b->address, hi, lo);
402 		return 0;
403 	}
404 
405 	return 1;
406 };
407 
408 /* Reprogram MCx_MISC MSR behind this threshold bank. */
409 static void threshold_restart_bank(void *_tr)
410 {
411 	struct thresh_restart *tr = _tr;
412 	u32 hi, lo;
413 
414 	/* sysfs write might race against an offline operation */
415 	if (this_cpu_read(threshold_banks))
416 		return;
417 
418 	rdmsr(tr->b->address, lo, hi);
419 
420 	if (tr->b->threshold_limit < (hi & THRESHOLD_MAX))
421 		tr->reset = 1;	/* limit cannot be lower than err count */
422 
423 	if (tr->reset) {		/* reset err count and overflow bit */
424 		hi =
425 		    (hi & ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI)) |
426 		    (THRESHOLD_MAX - tr->b->threshold_limit);
427 	} else if (tr->old_limit) {	/* change limit w/o reset */
428 		int new_count = (hi & THRESHOLD_MAX) +
429 		    (tr->old_limit - tr->b->threshold_limit);
430 
431 		hi = (hi & ~MASK_ERR_COUNT_HI) |
432 		    (new_count & THRESHOLD_MAX);
433 	}
434 
435 	/* clear IntType */
436 	hi &= ~MASK_INT_TYPE_HI;
437 
438 	if (!tr->b->interrupt_capable)
439 		goto done;
440 
441 	if (tr->set_lvt_off) {
442 		if (lvt_off_valid(tr->b, tr->lvt_off, lo, hi)) {
443 			/* set new lvt offset */
444 			hi &= ~MASK_LVTOFF_HI;
445 			hi |= tr->lvt_off << 20;
446 		}
447 	}
448 
449 	if (tr->b->interrupt_enable)
450 		hi |= INT_TYPE_APIC;
451 
452  done:
453 
454 	hi |= MASK_COUNT_EN_HI;
455 	wrmsr(tr->b->address, lo, hi);
456 }
457 
458 static void mce_threshold_block_init(struct threshold_block *b, int offset)
459 {
460 	struct thresh_restart tr = {
461 		.b			= b,
462 		.set_lvt_off		= 1,
463 		.lvt_off		= offset,
464 	};
465 
466 	b->threshold_limit		= THRESHOLD_MAX;
467 	threshold_restart_bank(&tr);
468 };
469 
470 static int setup_APIC_mce_threshold(int reserved, int new)
471 {
472 	if (reserved < 0 && !setup_APIC_eilvt(new, THRESHOLD_APIC_VECTOR,
473 					      APIC_EILVT_MSG_FIX, 0))
474 		return new;
475 
476 	return reserved;
477 }
478 
479 static int setup_APIC_deferred_error(int reserved, int new)
480 {
481 	if (reserved < 0 && !setup_APIC_eilvt(new, DEFERRED_ERROR_VECTOR,
482 					      APIC_EILVT_MSG_FIX, 0))
483 		return new;
484 
485 	return reserved;
486 }
487 
488 static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
489 {
490 	u32 low = 0, high = 0;
491 	int def_offset = -1, def_new;
492 
493 	if (rdmsr_safe(MSR_CU_DEF_ERR, &low, &high))
494 		return;
495 
496 	def_new = (low & MASK_DEF_LVTOFF) >> 4;
497 	if (!(low & MASK_DEF_LVTOFF)) {
498 		pr_err(FW_BUG "Your BIOS is not setting up LVT offset 0x2 for deferred error IRQs correctly.\n");
499 		def_new = DEF_LVT_OFF;
500 		low = (low & ~MASK_DEF_LVTOFF) | (DEF_LVT_OFF << 4);
501 	}
502 
503 	def_offset = setup_APIC_deferred_error(def_offset, def_new);
504 	if ((def_offset == def_new) &&
505 	    (deferred_error_int_vector != amd_deferred_error_interrupt))
506 		deferred_error_int_vector = amd_deferred_error_interrupt;
507 
508 	if (!mce_flags.smca)
509 		low = (low & ~MASK_DEF_INT_TYPE) | DEF_INT_TYPE_APIC;
510 
511 	wrmsr(MSR_CU_DEF_ERR, low, high);
512 }
513 
514 static u32 smca_get_block_address(unsigned int bank, unsigned int block,
515 				  unsigned int cpu)
516 {
517 	if (!block)
518 		return MSR_AMD64_SMCA_MCx_MISC(bank);
519 
520 	if (!(per_cpu(smca_misc_banks_map, cpu) & BIT(bank)))
521 		return 0;
522 
523 	return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
524 }
525 
526 static u32 get_block_address(u32 current_addr, u32 low, u32 high,
527 			     unsigned int bank, unsigned int block,
528 			     unsigned int cpu)
529 {
530 	u32 addr = 0, offset = 0;
531 
532 	if ((bank >= per_cpu(mce_num_banks, cpu)) || (block >= NR_BLOCKS))
533 		return addr;
534 
535 	if (mce_flags.smca)
536 		return smca_get_block_address(bank, block, cpu);
537 
538 	/* Fall back to method we used for older processors: */
539 	switch (block) {
540 	case 0:
541 		addr = mca_msr_reg(bank, MCA_MISC);
542 		break;
543 	case 1:
544 		offset = ((low & MASK_BLKPTR_LO) >> 21);
545 		if (offset)
546 			addr = MCG_XBLK_ADDR + offset;
547 		break;
548 	default:
549 		addr = ++current_addr;
550 	}
551 	return addr;
552 }
553 
554 static int
555 prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
556 			int offset, u32 misc_high)
557 {
558 	unsigned int cpu = smp_processor_id();
559 	u32 smca_low, smca_high;
560 	struct threshold_block b;
561 	int new;
562 
563 	if (!block)
564 		per_cpu(bank_map, cpu) |= (1 << bank);
565 
566 	memset(&b, 0, sizeof(b));
567 	b.cpu			= cpu;
568 	b.bank			= bank;
569 	b.block			= block;
570 	b.address		= addr;
571 	b.interrupt_capable	= lvt_interrupt_supported(bank, misc_high);
572 
573 	if (!b.interrupt_capable)
574 		goto done;
575 
576 	b.interrupt_enable = 1;
577 
578 	if (!mce_flags.smca) {
579 		new = (misc_high & MASK_LVTOFF_HI) >> 20;
580 		goto set_offset;
581 	}
582 
583 	/* Gather LVT offset for thresholding: */
584 	if (rdmsr_safe(MSR_CU_DEF_ERR, &smca_low, &smca_high))
585 		goto out;
586 
587 	new = (smca_low & SMCA_THR_LVT_OFF) >> 12;
588 
589 set_offset:
590 	offset = setup_APIC_mce_threshold(offset, new);
591 	if (offset == new)
592 		thresholding_irq_en = true;
593 
594 done:
595 	mce_threshold_block_init(&b, offset);
596 
597 out:
598 	return offset;
599 }
600 
601 bool amd_filter_mce(struct mce *m)
602 {
603 	enum smca_bank_types bank_type = smca_get_bank_type(m->bank);
604 	struct cpuinfo_x86 *c = &boot_cpu_data;
605 
606 	/* See Family 17h Models 10h-2Fh Erratum #1114. */
607 	if (c->x86 == 0x17 &&
608 	    c->x86_model >= 0x10 && c->x86_model <= 0x2F &&
609 	    bank_type == SMCA_IF && XEC(m->status, 0x3f) == 10)
610 		return true;
611 
612 	/* NB GART TLB error reporting is disabled by default. */
613 	if (c->x86 < 0x17) {
614 		if (m->bank == 4 && XEC(m->status, 0x1f) == 0x5)
615 			return true;
616 	}
617 
618 	return false;
619 }
620 
621 /*
622  * Turn off thresholding banks for the following conditions:
623  * - MC4_MISC thresholding is not supported on Family 0x15.
624  * - Prevent possible spurious interrupts from the IF bank on Family 0x17
625  *   Models 0x10-0x2F due to Erratum #1114.
626  */
627 static void disable_err_thresholding(struct cpuinfo_x86 *c, unsigned int bank)
628 {
629 	int i, num_msrs;
630 	u64 hwcr;
631 	bool need_toggle;
632 	u32 msrs[NR_BLOCKS];
633 
634 	if (c->x86 == 0x15 && bank == 4) {
635 		msrs[0] = 0x00000413; /* MC4_MISC0 */
636 		msrs[1] = 0xc0000408; /* MC4_MISC1 */
637 		num_msrs = 2;
638 	} else if (c->x86 == 0x17 &&
639 		   (c->x86_model >= 0x10 && c->x86_model <= 0x2F)) {
640 
641 		if (smca_get_bank_type(bank) != SMCA_IF)
642 			return;
643 
644 		msrs[0] = MSR_AMD64_SMCA_MCx_MISC(bank);
645 		num_msrs = 1;
646 	} else {
647 		return;
648 	}
649 
650 	rdmsrl(MSR_K7_HWCR, hwcr);
651 
652 	/* McStatusWrEn has to be set */
653 	need_toggle = !(hwcr & BIT(18));
654 	if (need_toggle)
655 		wrmsrl(MSR_K7_HWCR, hwcr | BIT(18));
656 
657 	/* Clear CntP bit safely */
658 	for (i = 0; i < num_msrs; i++)
659 		msr_clear_bit(msrs[i], 62);
660 
661 	/* restore old settings */
662 	if (need_toggle)
663 		wrmsrl(MSR_K7_HWCR, hwcr);
664 }
665 
666 /* cpu init entry point, called from mce.c with preempt off */
667 void mce_amd_feature_init(struct cpuinfo_x86 *c)
668 {
669 	unsigned int bank, block, cpu = smp_processor_id();
670 	u32 low = 0, high = 0, address = 0;
671 	int offset = -1;
672 
673 
674 	for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
675 		if (mce_flags.smca)
676 			smca_configure(bank, cpu);
677 
678 		disable_err_thresholding(c, bank);
679 
680 		for (block = 0; block < NR_BLOCKS; ++block) {
681 			address = get_block_address(address, low, high, bank, block, cpu);
682 			if (!address)
683 				break;
684 
685 			if (rdmsr_safe(address, &low, &high))
686 				break;
687 
688 			if (!(high & MASK_VALID_HI))
689 				continue;
690 
691 			if (!(high & MASK_CNTP_HI)  ||
692 			     (high & MASK_LOCKED_HI))
693 				continue;
694 
695 			offset = prepare_threshold_block(bank, block, address, offset, high);
696 		}
697 	}
698 
699 	if (mce_flags.succor)
700 		deferred_error_interrupt_enable(c);
701 }
702 
703 bool amd_mce_is_memory_error(struct mce *m)
704 {
705 	/* ErrCodeExt[20:16] */
706 	u8 xec = (m->status >> 16) & 0x1f;
707 
708 	if (mce_flags.smca)
709 		return smca_get_bank_type(m->bank) == SMCA_UMC && xec == 0x0;
710 
711 	return m->bank == 4 && xec == 0x8;
712 }
713 
714 static void __log_error(unsigned int bank, u64 status, u64 addr, u64 misc)
715 {
716 	struct mce m;
717 
718 	mce_setup(&m);
719 
720 	m.status = status;
721 	m.misc   = misc;
722 	m.bank   = bank;
723 	m.tsc	 = rdtsc();
724 
725 	if (m.status & MCI_STATUS_ADDRV) {
726 		m.addr = addr;
727 
728 		/*
729 		 * Extract [55:<lsb>] where lsb is the least significant
730 		 * *valid* bit of the address bits.
731 		 */
732 		if (mce_flags.smca) {
733 			u8 lsb = (m.addr >> 56) & 0x3f;
734 
735 			m.addr &= GENMASK_ULL(55, lsb);
736 		}
737 	}
738 
739 	if (mce_flags.smca) {
740 		rdmsrl(MSR_AMD64_SMCA_MCx_IPID(bank), m.ipid);
741 
742 		if (m.status & MCI_STATUS_SYNDV)
743 			rdmsrl(MSR_AMD64_SMCA_MCx_SYND(bank), m.synd);
744 	}
745 
746 	mce_log(&m);
747 }
748 
749 DEFINE_IDTENTRY_SYSVEC(sysvec_deferred_error)
750 {
751 	trace_deferred_error_apic_entry(DEFERRED_ERROR_VECTOR);
752 	inc_irq_stat(irq_deferred_error_count);
753 	deferred_error_int_vector();
754 	trace_deferred_error_apic_exit(DEFERRED_ERROR_VECTOR);
755 	ack_APIC_irq();
756 }
757 
758 /*
759  * Returns true if the logged error is deferred. False, otherwise.
760  */
761 static inline bool
762 _log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
763 {
764 	u64 status, addr = 0;
765 
766 	rdmsrl(msr_stat, status);
767 	if (!(status & MCI_STATUS_VAL))
768 		return false;
769 
770 	if (status & MCI_STATUS_ADDRV)
771 		rdmsrl(msr_addr, addr);
772 
773 	__log_error(bank, status, addr, misc);
774 
775 	wrmsrl(msr_stat, 0);
776 
777 	return status & MCI_STATUS_DEFERRED;
778 }
779 
780 /*
781  * We have three scenarios for checking for Deferred errors:
782  *
783  * 1) Non-SMCA systems check MCA_STATUS and log error if found.
784  * 2) SMCA systems check MCA_STATUS. If error is found then log it and also
785  *    clear MCA_DESTAT.
786  * 3) SMCA systems check MCA_DESTAT, if error was not found in MCA_STATUS, and
787  *    log it.
788  */
789 static void log_error_deferred(unsigned int bank)
790 {
791 	bool defrd;
792 
793 	defrd = _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS),
794 				mca_msr_reg(bank, MCA_ADDR), 0);
795 
796 	if (!mce_flags.smca)
797 		return;
798 
799 	/* Clear MCA_DESTAT if we logged the deferred error from MCA_STATUS. */
800 	if (defrd) {
801 		wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
802 		return;
803 	}
804 
805 	/*
806 	 * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check
807 	 * for a valid error.
808 	 */
809 	_log_error_bank(bank, MSR_AMD64_SMCA_MCx_DESTAT(bank),
810 			      MSR_AMD64_SMCA_MCx_DEADDR(bank), 0);
811 }
812 
813 /* APIC interrupt handler for deferred errors */
814 static void amd_deferred_error_interrupt(void)
815 {
816 	unsigned int bank;
817 
818 	for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank)
819 		log_error_deferred(bank);
820 }
821 
822 static void log_error_thresholding(unsigned int bank, u64 misc)
823 {
824 	_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), mca_msr_reg(bank, MCA_ADDR), misc);
825 }
826 
827 static void log_and_reset_block(struct threshold_block *block)
828 {
829 	struct thresh_restart tr;
830 	u32 low = 0, high = 0;
831 
832 	if (!block)
833 		return;
834 
835 	if (rdmsr_safe(block->address, &low, &high))
836 		return;
837 
838 	if (!(high & MASK_OVERFLOW_HI))
839 		return;
840 
841 	/* Log the MCE which caused the threshold event. */
842 	log_error_thresholding(block->bank, ((u64)high << 32) | low);
843 
844 	/* Reset threshold block after logging error. */
845 	memset(&tr, 0, sizeof(tr));
846 	tr.b = block;
847 	threshold_restart_bank(&tr);
848 }
849 
850 /*
851  * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
852  * goes off when error_count reaches threshold_limit.
853  */
854 static void amd_threshold_interrupt(void)
855 {
856 	struct threshold_block *first_block = NULL, *block = NULL, *tmp = NULL;
857 	struct threshold_bank **bp = this_cpu_read(threshold_banks);
858 	unsigned int bank, cpu = smp_processor_id();
859 
860 	/*
861 	 * Validate that the threshold bank has been initialized already. The
862 	 * handler is installed at boot time, but on a hotplug event the
863 	 * interrupt might fire before the data has been initialized.
864 	 */
865 	if (!bp)
866 		return;
867 
868 	for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
869 		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
870 			continue;
871 
872 		first_block = bp[bank]->blocks;
873 		if (!first_block)
874 			continue;
875 
876 		/*
877 		 * The first block is also the head of the list. Check it first
878 		 * before iterating over the rest.
879 		 */
880 		log_and_reset_block(first_block);
881 		list_for_each_entry_safe(block, tmp, &first_block->miscj, miscj)
882 			log_and_reset_block(block);
883 	}
884 }
885 
886 /*
887  * Sysfs Interface
888  */
889 
890 struct threshold_attr {
891 	struct attribute attr;
892 	ssize_t (*show) (struct threshold_block *, char *);
893 	ssize_t (*store) (struct threshold_block *, const char *, size_t count);
894 };
895 
896 #define SHOW_FIELDS(name)						\
897 static ssize_t show_ ## name(struct threshold_block *b, char *buf)	\
898 {									\
899 	return sprintf(buf, "%lu\n", (unsigned long) b->name);		\
900 }
901 SHOW_FIELDS(interrupt_enable)
902 SHOW_FIELDS(threshold_limit)
903 
904 static ssize_t
905 store_interrupt_enable(struct threshold_block *b, const char *buf, size_t size)
906 {
907 	struct thresh_restart tr;
908 	unsigned long new;
909 
910 	if (!b->interrupt_capable)
911 		return -EINVAL;
912 
913 	if (kstrtoul(buf, 0, &new) < 0)
914 		return -EINVAL;
915 
916 	b->interrupt_enable = !!new;
917 
918 	memset(&tr, 0, sizeof(tr));
919 	tr.b		= b;
920 
921 	if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
922 		return -ENODEV;
923 
924 	return size;
925 }
926 
927 static ssize_t
928 store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
929 {
930 	struct thresh_restart tr;
931 	unsigned long new;
932 
933 	if (kstrtoul(buf, 0, &new) < 0)
934 		return -EINVAL;
935 
936 	if (new > THRESHOLD_MAX)
937 		new = THRESHOLD_MAX;
938 	if (new < 1)
939 		new = 1;
940 
941 	memset(&tr, 0, sizeof(tr));
942 	tr.old_limit = b->threshold_limit;
943 	b->threshold_limit = new;
944 	tr.b = b;
945 
946 	if (smp_call_function_single(b->cpu, threshold_restart_bank, &tr, 1))
947 		return -ENODEV;
948 
949 	return size;
950 }
951 
952 static ssize_t show_error_count(struct threshold_block *b, char *buf)
953 {
954 	u32 lo, hi;
955 
956 	/* CPU might be offline by now */
957 	if (rdmsr_on_cpu(b->cpu, b->address, &lo, &hi))
958 		return -ENODEV;
959 
960 	return sprintf(buf, "%u\n", ((hi & THRESHOLD_MAX) -
961 				     (THRESHOLD_MAX - b->threshold_limit)));
962 }
963 
964 static struct threshold_attr error_count = {
965 	.attr = {.name = __stringify(error_count), .mode = 0444 },
966 	.show = show_error_count,
967 };
968 
969 #define RW_ATTR(val)							\
970 static struct threshold_attr val = {					\
971 	.attr	= {.name = __stringify(val), .mode = 0644 },		\
972 	.show	= show_## val,						\
973 	.store	= store_## val,						\
974 };
975 
976 RW_ATTR(interrupt_enable);
977 RW_ATTR(threshold_limit);
978 
979 static struct attribute *default_attrs[] = {
980 	&threshold_limit.attr,
981 	&error_count.attr,
982 	NULL,	/* possibly interrupt_enable if supported, see below */
983 	NULL,
984 };
985 
986 #define to_block(k)	container_of(k, struct threshold_block, kobj)
987 #define to_attr(a)	container_of(a, struct threshold_attr, attr)
988 
989 static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
990 {
991 	struct threshold_block *b = to_block(kobj);
992 	struct threshold_attr *a = to_attr(attr);
993 	ssize_t ret;
994 
995 	ret = a->show ? a->show(b, buf) : -EIO;
996 
997 	return ret;
998 }
999 
1000 static ssize_t store(struct kobject *kobj, struct attribute *attr,
1001 		     const char *buf, size_t count)
1002 {
1003 	struct threshold_block *b = to_block(kobj);
1004 	struct threshold_attr *a = to_attr(attr);
1005 	ssize_t ret;
1006 
1007 	ret = a->store ? a->store(b, buf, count) : -EIO;
1008 
1009 	return ret;
1010 }
1011 
1012 static const struct sysfs_ops threshold_ops = {
1013 	.show			= show,
1014 	.store			= store,
1015 };
1016 
1017 static void threshold_block_release(struct kobject *kobj);
1018 
1019 static struct kobj_type threshold_ktype = {
1020 	.sysfs_ops		= &threshold_ops,
1021 	.default_attrs		= default_attrs,
1022 	.release		= threshold_block_release,
1023 };
1024 
1025 static const char *get_name(unsigned int bank, struct threshold_block *b)
1026 {
1027 	enum smca_bank_types bank_type;
1028 
1029 	if (!mce_flags.smca) {
1030 		if (b && bank == 4)
1031 			return bank4_names(b);
1032 
1033 		return th_names[bank];
1034 	}
1035 
1036 	bank_type = smca_get_bank_type(bank);
1037 	if (bank_type >= N_SMCA_BANK_TYPES)
1038 		return NULL;
1039 
1040 	if (b && bank_type == SMCA_UMC) {
1041 		if (b->block < ARRAY_SIZE(smca_umc_block_names))
1042 			return smca_umc_block_names[b->block];
1043 		return NULL;
1044 	}
1045 
1046 	if (smca_banks[bank].hwid->count == 1)
1047 		return smca_get_name(bank_type);
1048 
1049 	snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN,
1050 		 "%s_%x", smca_get_name(bank_type),
1051 			  smca_banks[bank].sysfs_id);
1052 	return buf_mcatype;
1053 }
1054 
1055 static int allocate_threshold_blocks(unsigned int cpu, struct threshold_bank *tb,
1056 				     unsigned int bank, unsigned int block,
1057 				     u32 address)
1058 {
1059 	struct threshold_block *b = NULL;
1060 	u32 low, high;
1061 	int err;
1062 
1063 	if ((bank >= this_cpu_read(mce_num_banks)) || (block >= NR_BLOCKS))
1064 		return 0;
1065 
1066 	if (rdmsr_safe(address, &low, &high))
1067 		return 0;
1068 
1069 	if (!(high & MASK_VALID_HI)) {
1070 		if (block)
1071 			goto recurse;
1072 		else
1073 			return 0;
1074 	}
1075 
1076 	if (!(high & MASK_CNTP_HI)  ||
1077 	     (high & MASK_LOCKED_HI))
1078 		goto recurse;
1079 
1080 	b = kzalloc(sizeof(struct threshold_block), GFP_KERNEL);
1081 	if (!b)
1082 		return -ENOMEM;
1083 
1084 	b->block		= block;
1085 	b->bank			= bank;
1086 	b->cpu			= cpu;
1087 	b->address		= address;
1088 	b->interrupt_enable	= 0;
1089 	b->interrupt_capable	= lvt_interrupt_supported(bank, high);
1090 	b->threshold_limit	= THRESHOLD_MAX;
1091 
1092 	if (b->interrupt_capable) {
1093 		threshold_ktype.default_attrs[2] = &interrupt_enable.attr;
1094 		b->interrupt_enable = 1;
1095 	} else {
1096 		threshold_ktype.default_attrs[2] = NULL;
1097 	}
1098 
1099 	INIT_LIST_HEAD(&b->miscj);
1100 
1101 	/* This is safe as @tb is not visible yet */
1102 	if (tb->blocks)
1103 		list_add(&b->miscj, &tb->blocks->miscj);
1104 	else
1105 		tb->blocks = b;
1106 
1107 	err = kobject_init_and_add(&b->kobj, &threshold_ktype, tb->kobj, get_name(bank, b));
1108 	if (err)
1109 		goto out_free;
1110 recurse:
1111 	address = get_block_address(address, low, high, bank, ++block, cpu);
1112 	if (!address)
1113 		return 0;
1114 
1115 	err = allocate_threshold_blocks(cpu, tb, bank, block, address);
1116 	if (err)
1117 		goto out_free;
1118 
1119 	if (b)
1120 		kobject_uevent(&b->kobj, KOBJ_ADD);
1121 
1122 	return 0;
1123 
1124 out_free:
1125 	if (b) {
1126 		list_del(&b->miscj);
1127 		kobject_put(&b->kobj);
1128 	}
1129 	return err;
1130 }
1131 
1132 static int __threshold_add_blocks(struct threshold_bank *b)
1133 {
1134 	struct list_head *head = &b->blocks->miscj;
1135 	struct threshold_block *pos = NULL;
1136 	struct threshold_block *tmp = NULL;
1137 	int err = 0;
1138 
1139 	err = kobject_add(&b->blocks->kobj, b->kobj, b->blocks->kobj.name);
1140 	if (err)
1141 		return err;
1142 
1143 	list_for_each_entry_safe(pos, tmp, head, miscj) {
1144 
1145 		err = kobject_add(&pos->kobj, b->kobj, pos->kobj.name);
1146 		if (err) {
1147 			list_for_each_entry_safe_reverse(pos, tmp, head, miscj)
1148 				kobject_del(&pos->kobj);
1149 
1150 			return err;
1151 		}
1152 	}
1153 	return err;
1154 }
1155 
1156 static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
1157 				 unsigned int bank)
1158 {
1159 	struct device *dev = this_cpu_read(mce_device);
1160 	struct amd_northbridge *nb = NULL;
1161 	struct threshold_bank *b = NULL;
1162 	const char *name = get_name(bank, NULL);
1163 	int err = 0;
1164 
1165 	if (!dev)
1166 		return -ENODEV;
1167 
1168 	if (is_shared_bank(bank)) {
1169 		nb = node_to_amd_nb(topology_die_id(cpu));
1170 
1171 		/* threshold descriptor already initialized on this node? */
1172 		if (nb && nb->bank4) {
1173 			/* yes, use it */
1174 			b = nb->bank4;
1175 			err = kobject_add(b->kobj, &dev->kobj, name);
1176 			if (err)
1177 				goto out;
1178 
1179 			bp[bank] = b;
1180 			refcount_inc(&b->cpus);
1181 
1182 			err = __threshold_add_blocks(b);
1183 
1184 			goto out;
1185 		}
1186 	}
1187 
1188 	b = kzalloc(sizeof(struct threshold_bank), GFP_KERNEL);
1189 	if (!b) {
1190 		err = -ENOMEM;
1191 		goto out;
1192 	}
1193 
1194 	/* Associate the bank with the per-CPU MCE device */
1195 	b->kobj = kobject_create_and_add(name, &dev->kobj);
1196 	if (!b->kobj) {
1197 		err = -EINVAL;
1198 		goto out_free;
1199 	}
1200 
1201 	if (is_shared_bank(bank)) {
1202 		b->shared = 1;
1203 		refcount_set(&b->cpus, 1);
1204 
1205 		/* nb is already initialized, see above */
1206 		if (nb) {
1207 			WARN_ON(nb->bank4);
1208 			nb->bank4 = b;
1209 		}
1210 	}
1211 
1212 	err = allocate_threshold_blocks(cpu, b, bank, 0, mca_msr_reg(bank, MCA_MISC));
1213 	if (err)
1214 		goto out_kobj;
1215 
1216 	bp[bank] = b;
1217 	return 0;
1218 
1219 out_kobj:
1220 	kobject_put(b->kobj);
1221 out_free:
1222 	kfree(b);
1223 out:
1224 	return err;
1225 }
1226 
1227 static void threshold_block_release(struct kobject *kobj)
1228 {
1229 	kfree(to_block(kobj));
1230 }
1231 
1232 static void deallocate_threshold_blocks(struct threshold_bank *bank)
1233 {
1234 	struct threshold_block *pos, *tmp;
1235 
1236 	list_for_each_entry_safe(pos, tmp, &bank->blocks->miscj, miscj) {
1237 		list_del(&pos->miscj);
1238 		kobject_put(&pos->kobj);
1239 	}
1240 
1241 	kobject_put(&bank->blocks->kobj);
1242 }
1243 
1244 static void __threshold_remove_blocks(struct threshold_bank *b)
1245 {
1246 	struct threshold_block *pos = NULL;
1247 	struct threshold_block *tmp = NULL;
1248 
1249 	kobject_del(b->kobj);
1250 
1251 	list_for_each_entry_safe(pos, tmp, &b->blocks->miscj, miscj)
1252 		kobject_del(&pos->kobj);
1253 }
1254 
1255 static void threshold_remove_bank(struct threshold_bank *bank)
1256 {
1257 	struct amd_northbridge *nb;
1258 
1259 	if (!bank->blocks)
1260 		goto out_free;
1261 
1262 	if (!bank->shared)
1263 		goto out_dealloc;
1264 
1265 	if (!refcount_dec_and_test(&bank->cpus)) {
1266 		__threshold_remove_blocks(bank);
1267 		return;
1268 	} else {
1269 		/*
1270 		 * The last CPU on this node using the shared bank is going
1271 		 * away, remove that bank now.
1272 		 */
1273 		nb = node_to_amd_nb(topology_die_id(smp_processor_id()));
1274 		nb->bank4 = NULL;
1275 	}
1276 
1277 out_dealloc:
1278 	deallocate_threshold_blocks(bank);
1279 
1280 out_free:
1281 	kobject_put(bank->kobj);
1282 	kfree(bank);
1283 }
1284 
1285 int mce_threshold_remove_device(unsigned int cpu)
1286 {
1287 	struct threshold_bank **bp = this_cpu_read(threshold_banks);
1288 	unsigned int bank, numbanks = this_cpu_read(mce_num_banks);
1289 
1290 	if (!bp)
1291 		return 0;
1292 
1293 	/*
1294 	 * Clear the pointer before cleaning up, so that the interrupt won't
1295 	 * touch anything of this.
1296 	 */
1297 	this_cpu_write(threshold_banks, NULL);
1298 
1299 	for (bank = 0; bank < numbanks; bank++) {
1300 		if (bp[bank]) {
1301 			threshold_remove_bank(bp[bank]);
1302 			bp[bank] = NULL;
1303 		}
1304 	}
1305 	kfree(bp);
1306 	return 0;
1307 }
1308 
1309 /**
1310  * mce_threshold_create_device - Create the per-CPU MCE threshold device
1311  * @cpu:	The plugged in CPU
1312  *
1313  * Create directories and files for all valid threshold banks.
1314  *
1315  * This is invoked from the CPU hotplug callback which was installed in
1316  * mcheck_init_device(). The invocation happens in context of the hotplug
1317  * thread running on @cpu.  The callback is invoked on all CPUs which are
1318  * online when the callback is installed or during a real hotplug event.
1319  */
1320 int mce_threshold_create_device(unsigned int cpu)
1321 {
1322 	unsigned int numbanks, bank;
1323 	struct threshold_bank **bp;
1324 	int err;
1325 
1326 	if (!mce_flags.amd_threshold)
1327 		return 0;
1328 
1329 	bp = this_cpu_read(threshold_banks);
1330 	if (bp)
1331 		return 0;
1332 
1333 	numbanks = this_cpu_read(mce_num_banks);
1334 	bp = kcalloc(numbanks, sizeof(*bp), GFP_KERNEL);
1335 	if (!bp)
1336 		return -ENOMEM;
1337 
1338 	for (bank = 0; bank < numbanks; ++bank) {
1339 		if (!(this_cpu_read(bank_map) & (1 << bank)))
1340 			continue;
1341 		err = threshold_create_bank(bp, cpu, bank);
1342 		if (err)
1343 			goto out_err;
1344 	}
1345 	this_cpu_write(threshold_banks, bp);
1346 
1347 	if (thresholding_irq_en)
1348 		mce_threshold_vector = amd_threshold_interrupt;
1349 	return 0;
1350 out_err:
1351 	mce_threshold_remove_device(cpu);
1352 	return err;
1353 }
1354