xref: /linux/arch/x86/kernel/cpu/cacheinfo.c (revision 60684c2bd35064043360e6f716d1b7c20e967b7d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *	Routines to identify caches on Intel CPU.
4  *
5  *	Changes:
6  *	Venkatesh Pallipadi	: Adding cache identification through cpuid(4)
7  *	Ashok Raj <ashok.raj@intel.com>: Work with CPU hotplug infrastructure.
8  *	Andi Kleen / Andreas Herrmann	: CPUID4 emulation on AMD.
9  */
10 
11 #include <linux/slab.h>
12 #include <linux/cacheinfo.h>
13 #include <linux/cpu.h>
14 #include <linux/cpuhotplug.h>
15 #include <linux/sched.h>
16 #include <linux/capability.h>
17 #include <linux/sysfs.h>
18 #include <linux/pci.h>
19 #include <linux/stop_machine.h>
20 
21 #include <asm/cpufeature.h>
22 #include <asm/cacheinfo.h>
23 #include <asm/amd_nb.h>
24 #include <asm/smp.h>
25 #include <asm/mtrr.h>
26 #include <asm/tlbflush.h>
27 
28 #include "cpu.h"
29 
30 #define LVL_1_INST	1
31 #define LVL_1_DATA	2
32 #define LVL_2		3
33 #define LVL_3		4
34 #define LVL_TRACE	5
35 
36 /* Shared last level cache maps */
37 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
38 
39 /* Shared L2 cache maps */
40 DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map);
41 
42 /* Kernel controls MTRR and/or PAT MSRs. */
43 unsigned int memory_caching_control __ro_after_init;
44 
45 struct _cache_table {
46 	unsigned char descriptor;
47 	char cache_type;
48 	short size;
49 };
50 
51 #define MB(x)	((x) * 1024)
52 
53 /* All the cache descriptor types we care about (no TLB or
54    trace cache entries) */
55 
56 static const struct _cache_table cache_table[] =
57 {
58 	{ 0x06, LVL_1_INST, 8 },	/* 4-way set assoc, 32 byte line size */
59 	{ 0x08, LVL_1_INST, 16 },	/* 4-way set assoc, 32 byte line size */
60 	{ 0x09, LVL_1_INST, 32 },	/* 4-way set assoc, 64 byte line size */
61 	{ 0x0a, LVL_1_DATA, 8 },	/* 2 way set assoc, 32 byte line size */
62 	{ 0x0c, LVL_1_DATA, 16 },	/* 4-way set assoc, 32 byte line size */
63 	{ 0x0d, LVL_1_DATA, 16 },	/* 4-way set assoc, 64 byte line size */
64 	{ 0x0e, LVL_1_DATA, 24 },	/* 6-way set assoc, 64 byte line size */
65 	{ 0x21, LVL_2,      256 },	/* 8-way set assoc, 64 byte line size */
66 	{ 0x22, LVL_3,      512 },	/* 4-way set assoc, sectored cache, 64 byte line size */
67 	{ 0x23, LVL_3,      MB(1) },	/* 8-way set assoc, sectored cache, 64 byte line size */
68 	{ 0x25, LVL_3,      MB(2) },	/* 8-way set assoc, sectored cache, 64 byte line size */
69 	{ 0x29, LVL_3,      MB(4) },	/* 8-way set assoc, sectored cache, 64 byte line size */
70 	{ 0x2c, LVL_1_DATA, 32 },	/* 8-way set assoc, 64 byte line size */
71 	{ 0x30, LVL_1_INST, 32 },	/* 8-way set assoc, 64 byte line size */
72 	{ 0x39, LVL_2,      128 },	/* 4-way set assoc, sectored cache, 64 byte line size */
73 	{ 0x3a, LVL_2,      192 },	/* 6-way set assoc, sectored cache, 64 byte line size */
74 	{ 0x3b, LVL_2,      128 },	/* 2-way set assoc, sectored cache, 64 byte line size */
75 	{ 0x3c, LVL_2,      256 },	/* 4-way set assoc, sectored cache, 64 byte line size */
76 	{ 0x3d, LVL_2,      384 },	/* 6-way set assoc, sectored cache, 64 byte line size */
77 	{ 0x3e, LVL_2,      512 },	/* 4-way set assoc, sectored cache, 64 byte line size */
78 	{ 0x3f, LVL_2,      256 },	/* 2-way set assoc, 64 byte line size */
79 	{ 0x41, LVL_2,      128 },	/* 4-way set assoc, 32 byte line size */
80 	{ 0x42, LVL_2,      256 },	/* 4-way set assoc, 32 byte line size */
81 	{ 0x43, LVL_2,      512 },	/* 4-way set assoc, 32 byte line size */
82 	{ 0x44, LVL_2,      MB(1) },	/* 4-way set assoc, 32 byte line size */
83 	{ 0x45, LVL_2,      MB(2) },	/* 4-way set assoc, 32 byte line size */
84 	{ 0x46, LVL_3,      MB(4) },	/* 4-way set assoc, 64 byte line size */
85 	{ 0x47, LVL_3,      MB(8) },	/* 8-way set assoc, 64 byte line size */
86 	{ 0x48, LVL_2,      MB(3) },	/* 12-way set assoc, 64 byte line size */
87 	{ 0x49, LVL_3,      MB(4) },	/* 16-way set assoc, 64 byte line size */
88 	{ 0x4a, LVL_3,      MB(6) },	/* 12-way set assoc, 64 byte line size */
89 	{ 0x4b, LVL_3,      MB(8) },	/* 16-way set assoc, 64 byte line size */
90 	{ 0x4c, LVL_3,      MB(12) },	/* 12-way set assoc, 64 byte line size */
91 	{ 0x4d, LVL_3,      MB(16) },	/* 16-way set assoc, 64 byte line size */
92 	{ 0x4e, LVL_2,      MB(6) },	/* 24-way set assoc, 64 byte line size */
93 	{ 0x60, LVL_1_DATA, 16 },	/* 8-way set assoc, sectored cache, 64 byte line size */
94 	{ 0x66, LVL_1_DATA, 8 },	/* 4-way set assoc, sectored cache, 64 byte line size */
95 	{ 0x67, LVL_1_DATA, 16 },	/* 4-way set assoc, sectored cache, 64 byte line size */
96 	{ 0x68, LVL_1_DATA, 32 },	/* 4-way set assoc, sectored cache, 64 byte line size */
97 	{ 0x70, LVL_TRACE,  12 },	/* 8-way set assoc */
98 	{ 0x71, LVL_TRACE,  16 },	/* 8-way set assoc */
99 	{ 0x72, LVL_TRACE,  32 },	/* 8-way set assoc */
100 	{ 0x73, LVL_TRACE,  64 },	/* 8-way set assoc */
101 	{ 0x78, LVL_2,      MB(1) },	/* 4-way set assoc, 64 byte line size */
102 	{ 0x79, LVL_2,      128 },	/* 8-way set assoc, sectored cache, 64 byte line size */
103 	{ 0x7a, LVL_2,      256 },	/* 8-way set assoc, sectored cache, 64 byte line size */
104 	{ 0x7b, LVL_2,      512 },	/* 8-way set assoc, sectored cache, 64 byte line size */
105 	{ 0x7c, LVL_2,      MB(1) },	/* 8-way set assoc, sectored cache, 64 byte line size */
106 	{ 0x7d, LVL_2,      MB(2) },	/* 8-way set assoc, 64 byte line size */
107 	{ 0x7f, LVL_2,      512 },	/* 2-way set assoc, 64 byte line size */
108 	{ 0x80, LVL_2,      512 },	/* 8-way set assoc, 64 byte line size */
109 	{ 0x82, LVL_2,      256 },	/* 8-way set assoc, 32 byte line size */
110 	{ 0x83, LVL_2,      512 },	/* 8-way set assoc, 32 byte line size */
111 	{ 0x84, LVL_2,      MB(1) },	/* 8-way set assoc, 32 byte line size */
112 	{ 0x85, LVL_2,      MB(2) },	/* 8-way set assoc, 32 byte line size */
113 	{ 0x86, LVL_2,      512 },	/* 4-way set assoc, 64 byte line size */
114 	{ 0x87, LVL_2,      MB(1) },	/* 8-way set assoc, 64 byte line size */
115 	{ 0xd0, LVL_3,      512 },	/* 4-way set assoc, 64 byte line size */
116 	{ 0xd1, LVL_3,      MB(1) },	/* 4-way set assoc, 64 byte line size */
117 	{ 0xd2, LVL_3,      MB(2) },	/* 4-way set assoc, 64 byte line size */
118 	{ 0xd6, LVL_3,      MB(1) },	/* 8-way set assoc, 64 byte line size */
119 	{ 0xd7, LVL_3,      MB(2) },	/* 8-way set assoc, 64 byte line size */
120 	{ 0xd8, LVL_3,      MB(4) },	/* 12-way set assoc, 64 byte line size */
121 	{ 0xdc, LVL_3,      MB(2) },	/* 12-way set assoc, 64 byte line size */
122 	{ 0xdd, LVL_3,      MB(4) },	/* 12-way set assoc, 64 byte line size */
123 	{ 0xde, LVL_3,      MB(8) },	/* 12-way set assoc, 64 byte line size */
124 	{ 0xe2, LVL_3,      MB(2) },	/* 16-way set assoc, 64 byte line size */
125 	{ 0xe3, LVL_3,      MB(4) },	/* 16-way set assoc, 64 byte line size */
126 	{ 0xe4, LVL_3,      MB(8) },	/* 16-way set assoc, 64 byte line size */
127 	{ 0xea, LVL_3,      MB(12) },	/* 24-way set assoc, 64 byte line size */
128 	{ 0xeb, LVL_3,      MB(18) },	/* 24-way set assoc, 64 byte line size */
129 	{ 0xec, LVL_3,      MB(24) },	/* 24-way set assoc, 64 byte line size */
130 	{ 0x00, 0, 0}
131 };
132 
133 
134 enum _cache_type {
135 	CTYPE_NULL = 0,
136 	CTYPE_DATA = 1,
137 	CTYPE_INST = 2,
138 	CTYPE_UNIFIED = 3
139 };
140 
141 union _cpuid4_leaf_eax {
142 	struct {
143 		enum _cache_type	type:5;
144 		unsigned int		level:3;
145 		unsigned int		is_self_initializing:1;
146 		unsigned int		is_fully_associative:1;
147 		unsigned int		reserved:4;
148 		unsigned int		num_threads_sharing:12;
149 		unsigned int		num_cores_on_die:6;
150 	} split;
151 	u32 full;
152 };
153 
154 union _cpuid4_leaf_ebx {
155 	struct {
156 		unsigned int		coherency_line_size:12;
157 		unsigned int		physical_line_partition:10;
158 		unsigned int		ways_of_associativity:10;
159 	} split;
160 	u32 full;
161 };
162 
163 union _cpuid4_leaf_ecx {
164 	struct {
165 		unsigned int		number_of_sets:32;
166 	} split;
167 	u32 full;
168 };
169 
170 struct _cpuid4_info_regs {
171 	union _cpuid4_leaf_eax eax;
172 	union _cpuid4_leaf_ebx ebx;
173 	union _cpuid4_leaf_ecx ecx;
174 	unsigned int id;
175 	unsigned long size;
176 	struct amd_northbridge *nb;
177 };
178 
179 static unsigned short num_cache_leaves;
180 
181 /* AMD doesn't have CPUID4. Emulate it here to report the same
182    information to the user.  This makes some assumptions about the machine:
183    L2 not shared, no SMT etc. that is currently true on AMD CPUs.
184 
185    In theory the TLBs could be reported as fake type (they are in "dummy").
186    Maybe later */
187 union l1_cache {
188 	struct {
189 		unsigned line_size:8;
190 		unsigned lines_per_tag:8;
191 		unsigned assoc:8;
192 		unsigned size_in_kb:8;
193 	};
194 	unsigned val;
195 };
196 
197 union l2_cache {
198 	struct {
199 		unsigned line_size:8;
200 		unsigned lines_per_tag:4;
201 		unsigned assoc:4;
202 		unsigned size_in_kb:16;
203 	};
204 	unsigned val;
205 };
206 
207 union l3_cache {
208 	struct {
209 		unsigned line_size:8;
210 		unsigned lines_per_tag:4;
211 		unsigned assoc:4;
212 		unsigned res:2;
213 		unsigned size_encoded:14;
214 	};
215 	unsigned val;
216 };
217 
218 static const unsigned short assocs[] = {
219 	[1] = 1,
220 	[2] = 2,
221 	[4] = 4,
222 	[6] = 8,
223 	[8] = 16,
224 	[0xa] = 32,
225 	[0xb] = 48,
226 	[0xc] = 64,
227 	[0xd] = 96,
228 	[0xe] = 128,
229 	[0xf] = 0xffff /* fully associative - no way to show this currently */
230 };
231 
232 static const unsigned char levels[] = { 1, 1, 2, 3 };
233 static const unsigned char types[] = { 1, 2, 3, 3 };
234 
235 static const enum cache_type cache_type_map[] = {
236 	[CTYPE_NULL] = CACHE_TYPE_NOCACHE,
237 	[CTYPE_DATA] = CACHE_TYPE_DATA,
238 	[CTYPE_INST] = CACHE_TYPE_INST,
239 	[CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
240 };
241 
242 static void
243 amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax,
244 		     union _cpuid4_leaf_ebx *ebx,
245 		     union _cpuid4_leaf_ecx *ecx)
246 {
247 	unsigned dummy;
248 	unsigned line_size, lines_per_tag, assoc, size_in_kb;
249 	union l1_cache l1i, l1d;
250 	union l2_cache l2;
251 	union l3_cache l3;
252 	union l1_cache *l1 = &l1d;
253 
254 	eax->full = 0;
255 	ebx->full = 0;
256 	ecx->full = 0;
257 
258 	cpuid(0x80000005, &dummy, &dummy, &l1d.val, &l1i.val);
259 	cpuid(0x80000006, &dummy, &dummy, &l2.val, &l3.val);
260 
261 	switch (leaf) {
262 	case 1:
263 		l1 = &l1i;
264 		fallthrough;
265 	case 0:
266 		if (!l1->val)
267 			return;
268 		assoc = assocs[l1->assoc];
269 		line_size = l1->line_size;
270 		lines_per_tag = l1->lines_per_tag;
271 		size_in_kb = l1->size_in_kb;
272 		break;
273 	case 2:
274 		if (!l2.val)
275 			return;
276 		assoc = assocs[l2.assoc];
277 		line_size = l2.line_size;
278 		lines_per_tag = l2.lines_per_tag;
279 		/* cpu_data has errata corrections for K7 applied */
280 		size_in_kb = __this_cpu_read(cpu_info.x86_cache_size);
281 		break;
282 	case 3:
283 		if (!l3.val)
284 			return;
285 		assoc = assocs[l3.assoc];
286 		line_size = l3.line_size;
287 		lines_per_tag = l3.lines_per_tag;
288 		size_in_kb = l3.size_encoded * 512;
289 		if (boot_cpu_has(X86_FEATURE_AMD_DCM)) {
290 			size_in_kb = size_in_kb >> 1;
291 			assoc = assoc >> 1;
292 		}
293 		break;
294 	default:
295 		return;
296 	}
297 
298 	eax->split.is_self_initializing = 1;
299 	eax->split.type = types[leaf];
300 	eax->split.level = levels[leaf];
301 	eax->split.num_threads_sharing = 0;
302 	eax->split.num_cores_on_die = __this_cpu_read(cpu_info.x86_max_cores) - 1;
303 
304 
305 	if (assoc == 0xffff)
306 		eax->split.is_fully_associative = 1;
307 	ebx->split.coherency_line_size = line_size - 1;
308 	ebx->split.ways_of_associativity = assoc - 1;
309 	ebx->split.physical_line_partition = lines_per_tag - 1;
310 	ecx->split.number_of_sets = (size_in_kb * 1024) / line_size /
311 		(ebx->split.ways_of_associativity + 1) - 1;
312 }
313 
314 #if defined(CONFIG_AMD_NB) && defined(CONFIG_SYSFS)
315 
316 /*
317  * L3 cache descriptors
318  */
319 static void amd_calc_l3_indices(struct amd_northbridge *nb)
320 {
321 	struct amd_l3_cache *l3 = &nb->l3_cache;
322 	unsigned int sc0, sc1, sc2, sc3;
323 	u32 val = 0;
324 
325 	pci_read_config_dword(nb->misc, 0x1C4, &val);
326 
327 	/* calculate subcache sizes */
328 	l3->subcaches[0] = sc0 = !(val & BIT(0));
329 	l3->subcaches[1] = sc1 = !(val & BIT(4));
330 
331 	if (boot_cpu_data.x86 == 0x15) {
332 		l3->subcaches[0] = sc0 += !(val & BIT(1));
333 		l3->subcaches[1] = sc1 += !(val & BIT(5));
334 	}
335 
336 	l3->subcaches[2] = sc2 = !(val & BIT(8))  + !(val & BIT(9));
337 	l3->subcaches[3] = sc3 = !(val & BIT(12)) + !(val & BIT(13));
338 
339 	l3->indices = (max(max3(sc0, sc1, sc2), sc3) << 10) - 1;
340 }
341 
342 /*
343  * check whether a slot used for disabling an L3 index is occupied.
344  * @l3: L3 cache descriptor
345  * @slot: slot number (0..1)
346  *
347  * @returns: the disabled index if used or negative value if slot free.
348  */
349 static int amd_get_l3_disable_slot(struct amd_northbridge *nb, unsigned slot)
350 {
351 	unsigned int reg = 0;
352 
353 	pci_read_config_dword(nb->misc, 0x1BC + slot * 4, &reg);
354 
355 	/* check whether this slot is activated already */
356 	if (reg & (3UL << 30))
357 		return reg & 0xfff;
358 
359 	return -1;
360 }
361 
362 static ssize_t show_cache_disable(struct cacheinfo *this_leaf, char *buf,
363 				  unsigned int slot)
364 {
365 	int index;
366 	struct amd_northbridge *nb = this_leaf->priv;
367 
368 	index = amd_get_l3_disable_slot(nb, slot);
369 	if (index >= 0)
370 		return sprintf(buf, "%d\n", index);
371 
372 	return sprintf(buf, "FREE\n");
373 }
374 
375 #define SHOW_CACHE_DISABLE(slot)					\
376 static ssize_t								\
377 cache_disable_##slot##_show(struct device *dev,				\
378 			    struct device_attribute *attr, char *buf)	\
379 {									\
380 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);		\
381 	return show_cache_disable(this_leaf, buf, slot);		\
382 }
383 SHOW_CACHE_DISABLE(0)
384 SHOW_CACHE_DISABLE(1)
385 
386 static void amd_l3_disable_index(struct amd_northbridge *nb, int cpu,
387 				 unsigned slot, unsigned long idx)
388 {
389 	int i;
390 
391 	idx |= BIT(30);
392 
393 	/*
394 	 *  disable index in all 4 subcaches
395 	 */
396 	for (i = 0; i < 4; i++) {
397 		u32 reg = idx | (i << 20);
398 
399 		if (!nb->l3_cache.subcaches[i])
400 			continue;
401 
402 		pci_write_config_dword(nb->misc, 0x1BC + slot * 4, reg);
403 
404 		/*
405 		 * We need to WBINVD on a core on the node containing the L3
406 		 * cache which indices we disable therefore a simple wbinvd()
407 		 * is not sufficient.
408 		 */
409 		wbinvd_on_cpu(cpu);
410 
411 		reg |= BIT(31);
412 		pci_write_config_dword(nb->misc, 0x1BC + slot * 4, reg);
413 	}
414 }
415 
416 /*
417  * disable a L3 cache index by using a disable-slot
418  *
419  * @l3:    L3 cache descriptor
420  * @cpu:   A CPU on the node containing the L3 cache
421  * @slot:  slot number (0..1)
422  * @index: index to disable
423  *
424  * @return: 0 on success, error status on failure
425  */
426 static int amd_set_l3_disable_slot(struct amd_northbridge *nb, int cpu,
427 			    unsigned slot, unsigned long index)
428 {
429 	int ret = 0;
430 
431 	/*  check if @slot is already used or the index is already disabled */
432 	ret = amd_get_l3_disable_slot(nb, slot);
433 	if (ret >= 0)
434 		return -EEXIST;
435 
436 	if (index > nb->l3_cache.indices)
437 		return -EINVAL;
438 
439 	/* check whether the other slot has disabled the same index already */
440 	if (index == amd_get_l3_disable_slot(nb, !slot))
441 		return -EEXIST;
442 
443 	amd_l3_disable_index(nb, cpu, slot, index);
444 
445 	return 0;
446 }
447 
448 static ssize_t store_cache_disable(struct cacheinfo *this_leaf,
449 				   const char *buf, size_t count,
450 				   unsigned int slot)
451 {
452 	unsigned long val = 0;
453 	int cpu, err = 0;
454 	struct amd_northbridge *nb = this_leaf->priv;
455 
456 	if (!capable(CAP_SYS_ADMIN))
457 		return -EPERM;
458 
459 	cpu = cpumask_first(&this_leaf->shared_cpu_map);
460 
461 	if (kstrtoul(buf, 10, &val) < 0)
462 		return -EINVAL;
463 
464 	err = amd_set_l3_disable_slot(nb, cpu, slot, val);
465 	if (err) {
466 		if (err == -EEXIST)
467 			pr_warn("L3 slot %d in use/index already disabled!\n",
468 				   slot);
469 		return err;
470 	}
471 	return count;
472 }
473 
474 #define STORE_CACHE_DISABLE(slot)					\
475 static ssize_t								\
476 cache_disable_##slot##_store(struct device *dev,			\
477 			     struct device_attribute *attr,		\
478 			     const char *buf, size_t count)		\
479 {									\
480 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);		\
481 	return store_cache_disable(this_leaf, buf, count, slot);	\
482 }
483 STORE_CACHE_DISABLE(0)
484 STORE_CACHE_DISABLE(1)
485 
486 static ssize_t subcaches_show(struct device *dev,
487 			      struct device_attribute *attr, char *buf)
488 {
489 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
490 	int cpu = cpumask_first(&this_leaf->shared_cpu_map);
491 
492 	return sprintf(buf, "%x\n", amd_get_subcaches(cpu));
493 }
494 
495 static ssize_t subcaches_store(struct device *dev,
496 			       struct device_attribute *attr,
497 			       const char *buf, size_t count)
498 {
499 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
500 	int cpu = cpumask_first(&this_leaf->shared_cpu_map);
501 	unsigned long val;
502 
503 	if (!capable(CAP_SYS_ADMIN))
504 		return -EPERM;
505 
506 	if (kstrtoul(buf, 16, &val) < 0)
507 		return -EINVAL;
508 
509 	if (amd_set_subcaches(cpu, val))
510 		return -EINVAL;
511 
512 	return count;
513 }
514 
515 static DEVICE_ATTR_RW(cache_disable_0);
516 static DEVICE_ATTR_RW(cache_disable_1);
517 static DEVICE_ATTR_RW(subcaches);
518 
519 static umode_t
520 cache_private_attrs_is_visible(struct kobject *kobj,
521 			       struct attribute *attr, int unused)
522 {
523 	struct device *dev = kobj_to_dev(kobj);
524 	struct cacheinfo *this_leaf = dev_get_drvdata(dev);
525 	umode_t mode = attr->mode;
526 
527 	if (!this_leaf->priv)
528 		return 0;
529 
530 	if ((attr == &dev_attr_subcaches.attr) &&
531 	    amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
532 		return mode;
533 
534 	if ((attr == &dev_attr_cache_disable_0.attr ||
535 	     attr == &dev_attr_cache_disable_1.attr) &&
536 	    amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
537 		return mode;
538 
539 	return 0;
540 }
541 
542 static struct attribute_group cache_private_group = {
543 	.is_visible = cache_private_attrs_is_visible,
544 };
545 
546 static void init_amd_l3_attrs(void)
547 {
548 	int n = 1;
549 	static struct attribute **amd_l3_attrs;
550 
551 	if (amd_l3_attrs) /* already initialized */
552 		return;
553 
554 	if (amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE))
555 		n += 2;
556 	if (amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
557 		n += 1;
558 
559 	amd_l3_attrs = kcalloc(n, sizeof(*amd_l3_attrs), GFP_KERNEL);
560 	if (!amd_l3_attrs)
561 		return;
562 
563 	n = 0;
564 	if (amd_nb_has_feature(AMD_NB_L3_INDEX_DISABLE)) {
565 		amd_l3_attrs[n++] = &dev_attr_cache_disable_0.attr;
566 		amd_l3_attrs[n++] = &dev_attr_cache_disable_1.attr;
567 	}
568 	if (amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
569 		amd_l3_attrs[n++] = &dev_attr_subcaches.attr;
570 
571 	cache_private_group.attrs = amd_l3_attrs;
572 }
573 
574 const struct attribute_group *
575 cache_get_priv_group(struct cacheinfo *this_leaf)
576 {
577 	struct amd_northbridge *nb = this_leaf->priv;
578 
579 	if (this_leaf->level < 3 || !nb)
580 		return NULL;
581 
582 	if (nb && nb->l3_cache.indices)
583 		init_amd_l3_attrs();
584 
585 	return &cache_private_group;
586 }
587 
588 static void amd_init_l3_cache(struct _cpuid4_info_regs *this_leaf, int index)
589 {
590 	int node;
591 
592 	/* only for L3, and not in virtualized environments */
593 	if (index < 3)
594 		return;
595 
596 	node = topology_die_id(smp_processor_id());
597 	this_leaf->nb = node_to_amd_nb(node);
598 	if (this_leaf->nb && !this_leaf->nb->l3_cache.indices)
599 		amd_calc_l3_indices(this_leaf->nb);
600 }
601 #else
602 #define amd_init_l3_cache(x, y)
603 #endif  /* CONFIG_AMD_NB && CONFIG_SYSFS */
604 
605 static int
606 cpuid4_cache_lookup_regs(int index, struct _cpuid4_info_regs *this_leaf)
607 {
608 	union _cpuid4_leaf_eax	eax;
609 	union _cpuid4_leaf_ebx	ebx;
610 	union _cpuid4_leaf_ecx	ecx;
611 	unsigned		edx;
612 
613 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
614 		if (boot_cpu_has(X86_FEATURE_TOPOEXT))
615 			cpuid_count(0x8000001d, index, &eax.full,
616 				    &ebx.full, &ecx.full, &edx);
617 		else
618 			amd_cpuid4(index, &eax, &ebx, &ecx);
619 		amd_init_l3_cache(this_leaf, index);
620 	} else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
621 		cpuid_count(0x8000001d, index, &eax.full,
622 			    &ebx.full, &ecx.full, &edx);
623 		amd_init_l3_cache(this_leaf, index);
624 	} else {
625 		cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx);
626 	}
627 
628 	if (eax.split.type == CTYPE_NULL)
629 		return -EIO; /* better error ? */
630 
631 	this_leaf->eax = eax;
632 	this_leaf->ebx = ebx;
633 	this_leaf->ecx = ecx;
634 	this_leaf->size = (ecx.split.number_of_sets          + 1) *
635 			  (ebx.split.coherency_line_size     + 1) *
636 			  (ebx.split.physical_line_partition + 1) *
637 			  (ebx.split.ways_of_associativity   + 1);
638 	return 0;
639 }
640 
641 static int find_num_cache_leaves(struct cpuinfo_x86 *c)
642 {
643 	unsigned int		eax, ebx, ecx, edx, op;
644 	union _cpuid4_leaf_eax	cache_eax;
645 	int 			i = -1;
646 
647 	if (c->x86_vendor == X86_VENDOR_AMD ||
648 	    c->x86_vendor == X86_VENDOR_HYGON)
649 		op = 0x8000001d;
650 	else
651 		op = 4;
652 
653 	do {
654 		++i;
655 		/* Do cpuid(op) loop to find out num_cache_leaves */
656 		cpuid_count(op, i, &eax, &ebx, &ecx, &edx);
657 		cache_eax.full = eax;
658 	} while (cache_eax.split.type != CTYPE_NULL);
659 	return i;
660 }
661 
662 void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, int cpu)
663 {
664 	/*
665 	 * We may have multiple LLCs if L3 caches exist, so check if we
666 	 * have an L3 cache by looking at the L3 cache CPUID leaf.
667 	 */
668 	if (!cpuid_edx(0x80000006))
669 		return;
670 
671 	if (c->x86 < 0x17) {
672 		/* LLC is at the node level. */
673 		per_cpu(cpu_llc_id, cpu) = c->cpu_die_id;
674 	} else if (c->x86 == 0x17 && c->x86_model <= 0x1F) {
675 		/*
676 		 * LLC is at the core complex level.
677 		 * Core complex ID is ApicId[3] for these processors.
678 		 */
679 		per_cpu(cpu_llc_id, cpu) = c->apicid >> 3;
680 	} else {
681 		/*
682 		 * LLC ID is calculated from the number of threads sharing the
683 		 * cache.
684 		 * */
685 		u32 eax, ebx, ecx, edx, num_sharing_cache = 0;
686 		u32 llc_index = find_num_cache_leaves(c) - 1;
687 
688 		cpuid_count(0x8000001d, llc_index, &eax, &ebx, &ecx, &edx);
689 		if (eax)
690 			num_sharing_cache = ((eax >> 14) & 0xfff) + 1;
691 
692 		if (num_sharing_cache) {
693 			int bits = get_count_order(num_sharing_cache);
694 
695 			per_cpu(cpu_llc_id, cpu) = c->apicid >> bits;
696 		}
697 	}
698 }
699 
700 void cacheinfo_hygon_init_llc_id(struct cpuinfo_x86 *c, int cpu)
701 {
702 	/*
703 	 * We may have multiple LLCs if L3 caches exist, so check if we
704 	 * have an L3 cache by looking at the L3 cache CPUID leaf.
705 	 */
706 	if (!cpuid_edx(0x80000006))
707 		return;
708 
709 	/*
710 	 * LLC is at the core complex level.
711 	 * Core complex ID is ApicId[3] for these processors.
712 	 */
713 	per_cpu(cpu_llc_id, cpu) = c->apicid >> 3;
714 }
715 
716 void init_amd_cacheinfo(struct cpuinfo_x86 *c)
717 {
718 
719 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
720 		num_cache_leaves = find_num_cache_leaves(c);
721 	} else if (c->extended_cpuid_level >= 0x80000006) {
722 		if (cpuid_edx(0x80000006) & 0xf000)
723 			num_cache_leaves = 4;
724 		else
725 			num_cache_leaves = 3;
726 	}
727 }
728 
729 void init_hygon_cacheinfo(struct cpuinfo_x86 *c)
730 {
731 	num_cache_leaves = find_num_cache_leaves(c);
732 }
733 
734 void init_intel_cacheinfo(struct cpuinfo_x86 *c)
735 {
736 	/* Cache sizes */
737 	unsigned int l1i = 0, l1d = 0, l2 = 0, l3 = 0;
738 	unsigned int new_l1d = 0, new_l1i = 0; /* Cache sizes from cpuid(4) */
739 	unsigned int new_l2 = 0, new_l3 = 0, i; /* Cache sizes from cpuid(4) */
740 	unsigned int l2_id = 0, l3_id = 0, num_threads_sharing, index_msb;
741 #ifdef CONFIG_SMP
742 	unsigned int cpu = c->cpu_index;
743 #endif
744 
745 	if (c->cpuid_level > 3) {
746 		static int is_initialized;
747 
748 		if (is_initialized == 0) {
749 			/* Init num_cache_leaves from boot CPU */
750 			num_cache_leaves = find_num_cache_leaves(c);
751 			is_initialized++;
752 		}
753 
754 		/*
755 		 * Whenever possible use cpuid(4), deterministic cache
756 		 * parameters cpuid leaf to find the cache details
757 		 */
758 		for (i = 0; i < num_cache_leaves; i++) {
759 			struct _cpuid4_info_regs this_leaf = {};
760 			int retval;
761 
762 			retval = cpuid4_cache_lookup_regs(i, &this_leaf);
763 			if (retval < 0)
764 				continue;
765 
766 			switch (this_leaf.eax.split.level) {
767 			case 1:
768 				if (this_leaf.eax.split.type == CTYPE_DATA)
769 					new_l1d = this_leaf.size/1024;
770 				else if (this_leaf.eax.split.type == CTYPE_INST)
771 					new_l1i = this_leaf.size/1024;
772 				break;
773 			case 2:
774 				new_l2 = this_leaf.size/1024;
775 				num_threads_sharing = 1 + this_leaf.eax.split.num_threads_sharing;
776 				index_msb = get_count_order(num_threads_sharing);
777 				l2_id = c->apicid & ~((1 << index_msb) - 1);
778 				break;
779 			case 3:
780 				new_l3 = this_leaf.size/1024;
781 				num_threads_sharing = 1 + this_leaf.eax.split.num_threads_sharing;
782 				index_msb = get_count_order(num_threads_sharing);
783 				l3_id = c->apicid & ~((1 << index_msb) - 1);
784 				break;
785 			default:
786 				break;
787 			}
788 		}
789 	}
790 	/*
791 	 * Don't use cpuid2 if cpuid4 is supported. For P4, we use cpuid2 for
792 	 * trace cache
793 	 */
794 	if ((num_cache_leaves == 0 || c->x86 == 15) && c->cpuid_level > 1) {
795 		/* supports eax=2  call */
796 		int j, n;
797 		unsigned int regs[4];
798 		unsigned char *dp = (unsigned char *)regs;
799 		int only_trace = 0;
800 
801 		if (num_cache_leaves != 0 && c->x86 == 15)
802 			only_trace = 1;
803 
804 		/* Number of times to iterate */
805 		n = cpuid_eax(2) & 0xFF;
806 
807 		for (i = 0 ; i < n ; i++) {
808 			cpuid(2, &regs[0], &regs[1], &regs[2], &regs[3]);
809 
810 			/* If bit 31 is set, this is an unknown format */
811 			for (j = 0 ; j < 3 ; j++)
812 				if (regs[j] & (1 << 31))
813 					regs[j] = 0;
814 
815 			/* Byte 0 is level count, not a descriptor */
816 			for (j = 1 ; j < 16 ; j++) {
817 				unsigned char des = dp[j];
818 				unsigned char k = 0;
819 
820 				/* look up this descriptor in the table */
821 				while (cache_table[k].descriptor != 0) {
822 					if (cache_table[k].descriptor == des) {
823 						if (only_trace && cache_table[k].cache_type != LVL_TRACE)
824 							break;
825 						switch (cache_table[k].cache_type) {
826 						case LVL_1_INST:
827 							l1i += cache_table[k].size;
828 							break;
829 						case LVL_1_DATA:
830 							l1d += cache_table[k].size;
831 							break;
832 						case LVL_2:
833 							l2 += cache_table[k].size;
834 							break;
835 						case LVL_3:
836 							l3 += cache_table[k].size;
837 							break;
838 						}
839 
840 						break;
841 					}
842 
843 					k++;
844 				}
845 			}
846 		}
847 	}
848 
849 	if (new_l1d)
850 		l1d = new_l1d;
851 
852 	if (new_l1i)
853 		l1i = new_l1i;
854 
855 	if (new_l2) {
856 		l2 = new_l2;
857 #ifdef CONFIG_SMP
858 		per_cpu(cpu_llc_id, cpu) = l2_id;
859 		per_cpu(cpu_l2c_id, cpu) = l2_id;
860 #endif
861 	}
862 
863 	if (new_l3) {
864 		l3 = new_l3;
865 #ifdef CONFIG_SMP
866 		per_cpu(cpu_llc_id, cpu) = l3_id;
867 #endif
868 	}
869 
870 #ifdef CONFIG_SMP
871 	/*
872 	 * If cpu_llc_id is not yet set, this means cpuid_level < 4 which in
873 	 * turns means that the only possibility is SMT (as indicated in
874 	 * cpuid1). Since cpuid2 doesn't specify shared caches, and we know
875 	 * that SMT shares all caches, we can unconditionally set cpu_llc_id to
876 	 * c->phys_proc_id.
877 	 */
878 	if (per_cpu(cpu_llc_id, cpu) == BAD_APICID)
879 		per_cpu(cpu_llc_id, cpu) = c->phys_proc_id;
880 #endif
881 
882 	c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));
883 
884 	if (!l2)
885 		cpu_detect_cache_sizes(c);
886 }
887 
888 static int __cache_amd_cpumap_setup(unsigned int cpu, int index,
889 				    struct _cpuid4_info_regs *base)
890 {
891 	struct cpu_cacheinfo *this_cpu_ci;
892 	struct cacheinfo *this_leaf;
893 	int i, sibling;
894 
895 	/*
896 	 * For L3, always use the pre-calculated cpu_llc_shared_mask
897 	 * to derive shared_cpu_map.
898 	 */
899 	if (index == 3) {
900 		for_each_cpu(i, cpu_llc_shared_mask(cpu)) {
901 			this_cpu_ci = get_cpu_cacheinfo(i);
902 			if (!this_cpu_ci->info_list)
903 				continue;
904 			this_leaf = this_cpu_ci->info_list + index;
905 			for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) {
906 				if (!cpu_online(sibling))
907 					continue;
908 				cpumask_set_cpu(sibling,
909 						&this_leaf->shared_cpu_map);
910 			}
911 		}
912 	} else if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
913 		unsigned int apicid, nshared, first, last;
914 
915 		nshared = base->eax.split.num_threads_sharing + 1;
916 		apicid = cpu_data(cpu).apicid;
917 		first = apicid - (apicid % nshared);
918 		last = first + nshared - 1;
919 
920 		for_each_online_cpu(i) {
921 			this_cpu_ci = get_cpu_cacheinfo(i);
922 			if (!this_cpu_ci->info_list)
923 				continue;
924 
925 			apicid = cpu_data(i).apicid;
926 			if ((apicid < first) || (apicid > last))
927 				continue;
928 
929 			this_leaf = this_cpu_ci->info_list + index;
930 
931 			for_each_online_cpu(sibling) {
932 				apicid = cpu_data(sibling).apicid;
933 				if ((apicid < first) || (apicid > last))
934 					continue;
935 				cpumask_set_cpu(sibling,
936 						&this_leaf->shared_cpu_map);
937 			}
938 		}
939 	} else
940 		return 0;
941 
942 	return 1;
943 }
944 
945 static void __cache_cpumap_setup(unsigned int cpu, int index,
946 				 struct _cpuid4_info_regs *base)
947 {
948 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
949 	struct cacheinfo *this_leaf, *sibling_leaf;
950 	unsigned long num_threads_sharing;
951 	int index_msb, i;
952 	struct cpuinfo_x86 *c = &cpu_data(cpu);
953 
954 	if (c->x86_vendor == X86_VENDOR_AMD ||
955 	    c->x86_vendor == X86_VENDOR_HYGON) {
956 		if (__cache_amd_cpumap_setup(cpu, index, base))
957 			return;
958 	}
959 
960 	this_leaf = this_cpu_ci->info_list + index;
961 	num_threads_sharing = 1 + base->eax.split.num_threads_sharing;
962 
963 	cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
964 	if (num_threads_sharing == 1)
965 		return;
966 
967 	index_msb = get_count_order(num_threads_sharing);
968 
969 	for_each_online_cpu(i)
970 		if (cpu_data(i).apicid >> index_msb == c->apicid >> index_msb) {
971 			struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);
972 
973 			if (i == cpu || !sib_cpu_ci->info_list)
974 				continue;/* skip if itself or no cacheinfo */
975 			sibling_leaf = sib_cpu_ci->info_list + index;
976 			cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
977 			cpumask_set_cpu(cpu, &sibling_leaf->shared_cpu_map);
978 		}
979 }
980 
981 static void ci_leaf_init(struct cacheinfo *this_leaf,
982 			 struct _cpuid4_info_regs *base)
983 {
984 	this_leaf->id = base->id;
985 	this_leaf->attributes = CACHE_ID;
986 	this_leaf->level = base->eax.split.level;
987 	this_leaf->type = cache_type_map[base->eax.split.type];
988 	this_leaf->coherency_line_size =
989 				base->ebx.split.coherency_line_size + 1;
990 	this_leaf->ways_of_associativity =
991 				base->ebx.split.ways_of_associativity + 1;
992 	this_leaf->size = base->size;
993 	this_leaf->number_of_sets = base->ecx.split.number_of_sets + 1;
994 	this_leaf->physical_line_partition =
995 				base->ebx.split.physical_line_partition + 1;
996 	this_leaf->priv = base->nb;
997 }
998 
999 int init_cache_level(unsigned int cpu)
1000 {
1001 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
1002 
1003 	if (!num_cache_leaves)
1004 		return -ENOENT;
1005 	if (!this_cpu_ci)
1006 		return -EINVAL;
1007 	this_cpu_ci->num_levels = 3;
1008 	this_cpu_ci->num_leaves = num_cache_leaves;
1009 	return 0;
1010 }
1011 
1012 /*
1013  * The max shared threads number comes from CPUID.4:EAX[25-14] with input
1014  * ECX as cache index. Then right shift apicid by the number's order to get
1015  * cache id for this cache node.
1016  */
1017 static void get_cache_id(int cpu, struct _cpuid4_info_regs *id4_regs)
1018 {
1019 	struct cpuinfo_x86 *c = &cpu_data(cpu);
1020 	unsigned long num_threads_sharing;
1021 	int index_msb;
1022 
1023 	num_threads_sharing = 1 + id4_regs->eax.split.num_threads_sharing;
1024 	index_msb = get_count_order(num_threads_sharing);
1025 	id4_regs->id = c->apicid >> index_msb;
1026 }
1027 
1028 int populate_cache_leaves(unsigned int cpu)
1029 {
1030 	unsigned int idx, ret;
1031 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
1032 	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
1033 	struct _cpuid4_info_regs id4_regs = {};
1034 
1035 	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
1036 		ret = cpuid4_cache_lookup_regs(idx, &id4_regs);
1037 		if (ret)
1038 			return ret;
1039 		get_cache_id(cpu, &id4_regs);
1040 		ci_leaf_init(this_leaf++, &id4_regs);
1041 		__cache_cpumap_setup(cpu, idx, &id4_regs);
1042 	}
1043 	this_cpu_ci->cpu_map_populated = true;
1044 
1045 	return 0;
1046 }
1047 
1048 /*
1049  * Disable and enable caches. Needed for changing MTRRs and the PAT MSR.
1050  *
1051  * Since we are disabling the cache don't allow any interrupts,
1052  * they would run extremely slow and would only increase the pain.
1053  *
1054  * The caller must ensure that local interrupts are disabled and
1055  * are reenabled after cache_enable() has been called.
1056  */
1057 static unsigned long saved_cr4;
1058 static DEFINE_RAW_SPINLOCK(cache_disable_lock);
1059 
1060 void cache_disable(void) __acquires(cache_disable_lock)
1061 {
1062 	unsigned long cr0;
1063 
1064 	/*
1065 	 * Note that this is not ideal
1066 	 * since the cache is only flushed/disabled for this CPU while the
1067 	 * MTRRs are changed, but changing this requires more invasive
1068 	 * changes to the way the kernel boots
1069 	 */
1070 
1071 	raw_spin_lock(&cache_disable_lock);
1072 
1073 	/* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
1074 	cr0 = read_cr0() | X86_CR0_CD;
1075 	write_cr0(cr0);
1076 
1077 	/*
1078 	 * Cache flushing is the most time-consuming step when programming
1079 	 * the MTRRs. Fortunately, as per the Intel Software Development
1080 	 * Manual, we can skip it if the processor supports cache self-
1081 	 * snooping.
1082 	 */
1083 	if (!static_cpu_has(X86_FEATURE_SELFSNOOP))
1084 		wbinvd();
1085 
1086 	/* Save value of CR4 and clear Page Global Enable (bit 7) */
1087 	if (cpu_feature_enabled(X86_FEATURE_PGE)) {
1088 		saved_cr4 = __read_cr4();
1089 		__write_cr4(saved_cr4 & ~X86_CR4_PGE);
1090 	}
1091 
1092 	/* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */
1093 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
1094 	flush_tlb_local();
1095 
1096 	if (cpu_feature_enabled(X86_FEATURE_MTRR))
1097 		mtrr_disable();
1098 
1099 	/* Again, only flush caches if we have to. */
1100 	if (!static_cpu_has(X86_FEATURE_SELFSNOOP))
1101 		wbinvd();
1102 }
1103 
1104 void cache_enable(void) __releases(cache_disable_lock)
1105 {
1106 	/* Flush TLBs (no need to flush caches - they are disabled) */
1107 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
1108 	flush_tlb_local();
1109 
1110 	if (cpu_feature_enabled(X86_FEATURE_MTRR))
1111 		mtrr_enable();
1112 
1113 	/* Enable caches */
1114 	write_cr0(read_cr0() & ~X86_CR0_CD);
1115 
1116 	/* Restore value of CR4 */
1117 	if (cpu_feature_enabled(X86_FEATURE_PGE))
1118 		__write_cr4(saved_cr4);
1119 
1120 	raw_spin_unlock(&cache_disable_lock);
1121 }
1122 
1123 static void cache_cpu_init(void)
1124 {
1125 	unsigned long flags;
1126 
1127 	local_irq_save(flags);
1128 	cache_disable();
1129 
1130 	if (memory_caching_control & CACHE_MTRR)
1131 		mtrr_generic_set_state();
1132 
1133 	if (memory_caching_control & CACHE_PAT)
1134 		pat_cpu_init();
1135 
1136 	cache_enable();
1137 	local_irq_restore(flags);
1138 }
1139 
1140 static bool cache_aps_delayed_init = true;
1141 
1142 void set_cache_aps_delayed_init(bool val)
1143 {
1144 	cache_aps_delayed_init = val;
1145 }
1146 
1147 bool get_cache_aps_delayed_init(void)
1148 {
1149 	return cache_aps_delayed_init;
1150 }
1151 
1152 static int cache_rendezvous_handler(void *unused)
1153 {
1154 	if (get_cache_aps_delayed_init() || !cpu_online(smp_processor_id()))
1155 		cache_cpu_init();
1156 
1157 	return 0;
1158 }
1159 
1160 void __init cache_bp_init(void)
1161 {
1162 	mtrr_bp_init();
1163 	pat_bp_init();
1164 
1165 	if (memory_caching_control)
1166 		cache_cpu_init();
1167 }
1168 
1169 void cache_bp_restore(void)
1170 {
1171 	if (memory_caching_control)
1172 		cache_cpu_init();
1173 }
1174 
1175 static int cache_ap_init(unsigned int cpu)
1176 {
1177 	if (!memory_caching_control || get_cache_aps_delayed_init())
1178 		return 0;
1179 
1180 	/*
1181 	 * Ideally we should hold mtrr_mutex here to avoid MTRR entries
1182 	 * changed, but this routine will be called in CPU boot time,
1183 	 * holding the lock breaks it.
1184 	 *
1185 	 * This routine is called in two cases:
1186 	 *
1187 	 *   1. very early time of software resume, when there absolutely
1188 	 *      isn't MTRR entry changes;
1189 	 *
1190 	 *   2. CPU hotadd time. We let mtrr_add/del_page hold cpuhotplug
1191 	 *      lock to prevent MTRR entry changes
1192 	 */
1193 	stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL,
1194 				       cpu_callout_mask);
1195 
1196 	return 0;
1197 }
1198 
1199 /*
1200  * Delayed cache initialization for all AP's
1201  */
1202 void cache_aps_init(void)
1203 {
1204 	if (!memory_caching_control || !get_cache_aps_delayed_init())
1205 		return;
1206 
1207 	stop_machine(cache_rendezvous_handler, NULL, cpu_online_mask);
1208 	set_cache_aps_delayed_init(false);
1209 }
1210 
1211 static int __init cache_ap_register(void)
1212 {
1213 	cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING,
1214 				  "x86/cachectrl:starting",
1215 				  cache_ap_init, NULL);
1216 	return 0;
1217 }
1218 core_initcall(cache_ap_register);
1219