path: root/arch/x86/kernel/cpu/cacheinfo.c

// SPDX-License-Identifier: GPL-2.0
/*
 *	Routines to identify caches on Intel CPU.
 *
 *	Changes:
 *	Venkatesh Pallipadi	: Adding cache identification through cpuid(4)
 *	Ashok Raj <ashok.raj@intel.com>: Work with CPU hotplug infrastructure.
 *	Andi Kleen / Andreas Herrmann	: CPUID4 emulation on AMD.
 */

#include <linux/cacheinfo.h>
#include <linux/cpu.h>
#include <linux/cpuhotplug.h>
#include <linux/stop_machine.h>

#include <asm/amd_nb.h>
#include <asm/cacheinfo.h>
#include <asm/cpufeature.h>
#include <asm/cpuid.h>
#include <asm/mtrr.h>
#include <asm/smp.h>
#include <asm/tlbflush.h>

#include "cpu.h"

#define LVL_1_INST	1
#define LVL_1_DATA	2
#define LVL_2		3
#define LVL_3		4

/* Shared last level cache maps */
DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);

/* Shared L2 cache maps */
DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_l2c_shared_map);

static cpumask_var_t cpu_cacheinfo_mask;

/* Kernel controls MTRR and/or PAT MSRs. */
unsigned int memory_caching_control __ro_after_init;

struct _cache_table {
	u8 descriptor;
	char cache_type;
	short size;
};

#define MB(x)	((x) * 1024)

/* All the cache descriptor types we care about (no TLB or
   trace cache entries) */

static const struct _cache_table cache_table[] =
{
	{ 0x06, LVL_1_INST, 8 },	/* 4-way set assoc, 32 byte line size */
	{ 0x08, LVL_1_INST, 16 },	/* 4-way set assoc, 32 byte line size */
	{ 0x09, LVL_1_INST, 32 },	/* 4-way set assoc, 64 byte line size */
	{ 0x0a, LVL_1_DATA, 8 },	/* 2 way set assoc, 32 byte line size */
	{ 0x0c, LVL_1_DATA, 16 },	/* 4-way set assoc, 32 byte line size */
	{ 0x0d, LVL_1_DATA, 16 },	/* 4-way set assoc, 64 byte line size */
	{ 0x0e, LVL_1_DATA, 24 },	/* 6-way set assoc, 64 byte line size */
	{ 0x21, LVL_2,      256 },	/* 8-way set assoc, 64 byte line size */
	{ 0x22, LVL_3,      512 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x23, LVL_3,      MB(1) },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x25, LVL_3,      MB(2) },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x29, LVL_3,      MB(4) },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x2c, LVL_1_DATA, 32 },	/* 8-way set assoc, 64 byte line size */
	{ 0x30, LVL_1_INST, 32 },	/* 8-way set assoc, 64 byte line size */
	{ 0x39, LVL_2,      128 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x3a, LVL_2,      192 },	/* 6-way set assoc, sectored cache, 64 byte line size */
	{ 0x3b, LVL_2,      128 },	/* 2-way set assoc, sectored cache, 64 byte line size */
	{ 0x3c, LVL_2,      256 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x3d, LVL_2,      384 },	/* 6-way set assoc, sectored cache, 64 byte line size */
	{ 0x3e, LVL_2,      512 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x3f, LVL_2,      256 },	/* 2-way set assoc, 64 byte line size */
	{ 0x41, LVL_2,      128 },	/* 4-way set assoc, 32 byte line size */
	{ 0x42, LVL_2,      256 },	/* 4-way set assoc, 32 byte line size */
	{ 0x43, LVL_2,      512 },	/* 4-way set assoc, 32 byte line size */
	{ 0x44, LVL_2,      MB(1) },	/* 4-way set assoc, 32 byte line size */
	{ 0x45, LVL_2,      MB(2) },	/* 4-way set assoc, 32 byte line size */
	{ 0x46, LVL_3,      MB(4) },	/* 4-way set assoc, 64 byte line size */
	{ 0x47, LVL_3,      MB(8) },	/* 8-way set assoc, 64 byte line size */
	{ 0x48, LVL_2,      MB(3) },	/* 12-way set assoc, 64 byte line size */
	{ 0x49, LVL_3,      MB(4) },	/* 16-way set assoc, 64 byte line size */
	{ 0x4a, LVL_3,      MB(6) },	/* 12-way set assoc, 64 byte line size */
	{ 0x4b, LVL_3,      MB(8) },	/* 16-way set assoc, 64 byte line size */
	{ 0x4c, LVL_3,      MB(12) },	/* 12-way set assoc, 64 byte line size */
	{ 0x4d, LVL_3,      MB(16) },	/* 16-way set assoc, 64 byte line size */
	{ 0x4e, LVL_2,      MB(6) },	/* 24-way set assoc, 64 byte line size */
	{ 0x60, LVL_1_DATA, 16 },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x66, LVL_1_DATA, 8 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x67, LVL_1_DATA, 16 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x68, LVL_1_DATA, 32 },	/* 4-way set assoc, sectored cache, 64 byte line size */
	{ 0x78, LVL_2,      MB(1) },	/* 4-way set assoc, 64 byte line size */
	{ 0x79, LVL_2,      128 },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x7a, LVL_2,      256 },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x7b, LVL_2,      512 },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x7c, LVL_2,      MB(1) },	/* 8-way set assoc, sectored cache, 64 byte line size */
	{ 0x7d, LVL_2,      MB(2) },	/* 8-way set assoc, 64 byte line size */
	{ 0x7f, LVL_2,      512 },	/* 2-way set assoc, 64 byte line size */
	{ 0x80, LVL_2,      512 },	/* 8-way set assoc, 64 byte line size */
	{ 0x82, LVL_2,      256 },	/* 8-way set assoc, 32 byte line size */
	{ 0x83, LVL_2,      512 },	/* 8-way set assoc, 32 byte line size */
	{ 0x84, LVL_2,      MB(1) },	/* 8-way set assoc, 32 byte line size */
	{ 0x85, LVL_2,      MB(2) },	/* 8-way set assoc, 32 byte line size */
	{ 0x86, LVL_2,      512 },	/* 4-way set assoc, 64 byte line size */
	{ 0x87, LVL_2,      MB(1) },	/* 8-way set assoc, 64 byte line size */
	{ 0xd0, LVL_3,      512 },	/* 4-way set assoc, 64 byte line size */
	{ 0xd1, LVL_3,      MB(1) },	/* 4-way set assoc, 64 byte line size */
	{ 0xd2, LVL_3,      MB(2) },	/* 4-way set assoc, 64 byte line size */
	{ 0xd6, LVL_3,      MB(1) },	/* 8-way set assoc, 64 byte line size */
	{ 0xd7, LVL_3,      MB(2) },	/* 8-way set assoc, 64 byte line size */
	{ 0xd8, LVL_3,      MB(4) },	/* 12-way set assoc, 64 byte line size */
	{ 0xdc, LVL_3,      MB(2) },	/* 12-way set assoc, 64 byte line size */
	{ 0xdd, LVL_3,      MB(4) },	/* 12-way set assoc, 64 byte line size */
	{ 0xde, LVL_3,      MB(8) },	/* 12-way set assoc, 64 byte line size */
	{ 0xe2, LVL_3,      MB(2) },	/* 16-way set assoc, 64 byte line size */
	{ 0xe3, LVL_3,      MB(4) },	/* 16-way set assoc, 64 byte line size */
	{ 0xe4, LVL_3,      MB(8) },	/* 16-way set assoc, 64 byte line size */
	{ 0xea, LVL_3,      MB(12) },	/* 24-way set assoc, 64 byte line size */
	{ 0xeb, LVL_3,      MB(18) },	/* 24-way set assoc, 64 byte line size */
	{ 0xec, LVL_3,      MB(24) },	/* 24-way set assoc, 64 byte line size */
};


enum _cache_type {
	CTYPE_NULL = 0,
	CTYPE_DATA = 1,
	CTYPE_INST = 2,
	CTYPE_UNIFIED = 3
};

union _cpuid4_leaf_eax {
	struct {
		enum _cache_type	type:5;
		unsigned int		level:3;
		unsigned int		is_self_initializing:1;
		unsigned int		is_fully_associative:1;
		unsigned int		reserved:4;
		unsigned int		num_threads_sharing:12;
		unsigned int		num_cores_on_die:6;
	} split;
	u32 full;
};

union _cpuid4_leaf_ebx {
	struct {
		unsigned int		coherency_line_size:12;
		unsigned int		physical_line_partition:10;
		unsigned int		ways_of_associativity:10;
	} split;
	u32 full;
};

union _cpuid4_leaf_ecx {
	struct {
		unsigned int		number_of_sets:32;
	} split;
	u32 full;
};

struct _cpuid4_info_regs {
	union _cpuid4_leaf_eax eax;
	union _cpuid4_leaf_ebx ebx;
	union _cpuid4_leaf_ecx ecx;
	unsigned int id;
	unsigned long size;
};

/* AMD doesn't have CPUID4. Emulate it here to report the same
   information to the user.  This makes some assumptions about the machine:
   L2 not shared, no SMT etc. that is currently true on AMD CPUs.

   In theory the TLBs could be reported as fake type (they are in "dummy").
   Maybe later */
union l1_cache {
	struct {
		unsigned line_size:8;
		unsigned lines_per_tag:8;
		unsigned assoc:8;
		unsigned size_in_kb:8;
	};
	unsigned val;
};

union l2_cache {
	struct {
		unsigned line_size:8;
		unsigned lines_per_tag:4;
		unsigned assoc:4;
		unsigned size_in_kb:16;
	};
	unsigned val;
};

union l3_cache {
	struct {
		unsigned line_size:8;
		unsigned lines_per_tag:4;
		unsigned assoc:4;
		unsigned res:2;
		unsigned size_encoded:14;
	};
	unsigned val;
};

static const unsigned short assocs[] = {
	[1] = 1,
	[2] = 2,
	[4] = 4,
	[6] = 8,
	[8] = 16,
	[0xa] = 32,
	[0xb] = 48,
	[0xc] = 64,
	[0xd] = 96,
	[0xe] = 128,
	[0xf] = 0xffff /* fully associative - no way to show this currently */
};

static const unsigned char levels[] = { 1, 1, 2, 3 };
static const unsigned char types[] = { 1, 2, 3, 3 };

static const enum cache_type cache_type_map[] = {
	[CTYPE_NULL] = CACHE_TYPE_NOCACHE,
	[CTYPE_DATA] = CACHE_TYPE_DATA,
	[CTYPE_INST] = CACHE_TYPE_INST,
	[CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
};

static void
amd_cpuid4(int index, union _cpuid4_leaf_eax *eax,
	   union _cpuid4_leaf_ebx *ebx, union _cpuid4_leaf_ecx *ecx)
{
	unsigned int dummy, line_size, lines_per_tag, assoc, size_in_kb;
	union l1_cache l1i, l1d;
	union l2_cache l2;
	union l3_cache l3;
	union l1_cache *l1 = &l1d;

	eax->full = 0;
	ebx->full = 0;
	ecx->full = 0;

	cpuid(0x80000005, &dummy, &dummy, &l1d.val, &l1i.val);
	cpuid(0x80000006, &dummy, &dummy, &l2.val, &l3.val);

	switch (index) {
	case 1:
		l1 = &l1i;
		fallthrough;
	case 0:
		if (!l1->val)
			return;
		assoc = assocs[l1->assoc];
		line_size = l1->line_size;
		lines_per_tag = l1->lines_per_tag;
		size_in_kb = l1->size_in_kb;
		break;
	case 2:
		if (!l2.val)
			return;
		assoc = assocs[l2.assoc];
		line_size = l2.line_size;
		lines_per_tag = l2.lines_per_tag;
		/* cpu_data has errata corrections for K7 applied */
		size_in_kb = __this_cpu_read(cpu_info.x86_cache_size);
		break;
	case 3:
		if (!l3.val)
			return;
		assoc = assocs[l3.assoc];
		line_size = l3.line_size;
		lines_per_tag = l3.lines_per_tag;
		size_in_kb = l3.size_encoded * 512;
		if (boot_cpu_has(X86_FEATURE_AMD_DCM)) {
			size_in_kb = size_in_kb >> 1;
			assoc = assoc >> 1;
		}
		break;
	default:
		return;
	}

	eax->split.is_self_initializing = 1;
	eax->split.type = types[index];
	eax->split.level = levels[index];
	eax->split.num_threads_sharing = 0;
	eax->split.num_cores_on_die = topology_num_cores_per_package();

	if (assoc == 0xffff)
		eax->split.is_fully_associative = 1;
	ebx->split.coherency_line_size = line_size - 1;
	ebx->split.ways_of_associativity = assoc - 1;
	ebx->split.physical_line_partition = lines_per_tag - 1;
	ecx->split.number_of_sets = (size_in_kb * 1024) / line_size /
		(ebx->split.ways_of_associativity + 1) - 1;
}

/*
 * Fill passed _cpuid4_info_regs structure.
 * Intel-only code paths should pass NULL for the amd_northbridge
 * return pointer.
 */
static int cpuid4_cache_lookup_regs(int index, struct _cpuid4_info_regs *id4,
				    struct amd_northbridge **nb)
{
	u8 cpu_vendor = boot_cpu_data.x86_vendor;
	union _cpuid4_leaf_eax eax;
	union _cpuid4_leaf_ebx ebx;
	union _cpuid4_leaf_ecx ecx;
	u32 edx;

	if (cpu_vendor == X86_VENDOR_AMD || cpu_vendor == X86_VENDOR_HYGON) {
		if (boot_cpu_has(X86_FEATURE_TOPOEXT) || cpu_vendor == X86_VENDOR_HYGON) {
			/* AMD with TOPOEXT, or HYGON */
			cpuid_count(0x8000001d, index, &eax.full, &ebx.full, &ecx.full, &edx);
		} else {
			/* Legacy AMD fallback */
			amd_cpuid4(index, &eax, &ebx, &ecx);
		}

		if (nb)
			*nb = amd_init_l3_cache(index);
	} else {
		/* Intel */
		cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx);
	}

	if (eax.split.type == CTYPE_NULL)
		return -EIO;

	id4->eax = eax;
	id4->ebx = ebx;
	id4->ecx = ecx;
	id4->size = (ecx.split.number_of_sets          + 1) *
		    (ebx.split.coherency_line_size     + 1) *
		    (ebx.split.physical_line_partition + 1) *
		    (ebx.split.ways_of_associativity   + 1);

	return 0;
}

static int find_num_cache_leaves(struct cpuinfo_x86 *c)
{
	unsigned int		eax, ebx, ecx, edx, op;
	union _cpuid4_leaf_eax	cache_eax;
	int 			i = -1;

	if (c->x86_vendor == X86_VENDOR_AMD ||
	    c->x86_vendor == X86_VENDOR_HYGON)
		op = 0x8000001d;
	else
		op = 4;

	do {
		++i;
		/* Do cpuid(op) loop to find out num_cache_leaves */
		cpuid_count(op, i, &eax, &ebx, &ecx, &edx);
		cache_eax.full = eax;
	} while (cache_eax.split.type != CTYPE_NULL);
	return i;
}

void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, u16 die_id)
{
	/*
	 * We may have multiple LLCs if L3 caches exist, so check if we
	 * have an L3 cache by looking at the L3 cache CPUID leaf.
	 */
	if (!cpuid_edx(0x80000006))
		return;

	if (c->x86 < 0x17) {
		/* LLC is at the node level. */
		c->topo.llc_id = die_id;
	} else if (c->x86 == 0x17 && c->x86_model <= 0x1F) {
		/*
		 * LLC is at the core complex level.
		 * Core complex ID is ApicId[3] for these processors.
		 */
		c->topo.llc_id = c->topo.apicid >> 3;
	} else {
		/*
		 * LLC ID is calculated from the number of threads sharing the
		 * cache.
		 * */
		u32 eax, ebx, ecx, edx, num_sharing_cache = 0;
		u32 llc_index = find_num_cache_leaves(c) - 1;

		cpuid_count(0x8000001d, llc_index, &eax, &ebx, &ecx, &edx);
		if (eax)
			num_sharing_cache = ((eax >> 14) & 0xfff) + 1;

		if (num_sharing_cache) {
			int bits = get_count_order(num_sharing_cache);

			c->topo.llc_id = c->topo.apicid >> bits;
		}
	}
}

void cacheinfo_hygon_init_llc_id(struct cpuinfo_x86 *c)
{
	/*
	 * We may have multiple LLCs if L3 caches exist, so check if we
	 * have an L3 cache by looking at the L3 cache CPUID leaf.
	 */
	if (!cpuid_edx(0x80000006))
		return;

	/*
	 * LLC is at the core complex level.
	 * Core complex ID is ApicId[3] for these processors.
	 */
	c->topo.llc_id = c->topo.apicid >> 3;
}

void init_amd_cacheinfo(struct cpuinfo_x86 *c)
{
	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(c->cpu_index);

	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
		ci->num_leaves = find_num_cache_leaves(c);
	} else if (c->extended_cpuid_level >= 0x80000006) {
		if (cpuid_edx(0x80000006) & 0xf000)
			ci->num_leaves = 4;
		else
			ci->num_leaves = 3;
	}
}

void init_hygon_cacheinfo(struct cpuinfo_x86 *c)
{
	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(c->cpu_index);

	ci->num_leaves = find_num_cache_leaves(c);
}

static const struct _cache_table *cache_table_get(u8 desc)
{
	for (int i = 0; i < ARRAY_SIZE(cache_table); i++) {
		if (cache_table[i].descriptor == desc)
			return &cache_table[i];
	}

	return NULL;
}

void init_intel_cacheinfo(struct cpuinfo_x86 *c)
{
	/* Cache sizes */
	unsigned int l1i = 0, l1d = 0, l2 = 0, l3 = 0;
	unsigned int new_l1d = 0, new_l1i = 0; /* Cache sizes from cpuid(4) */
	unsigned int new_l2 = 0, new_l3 = 0, i; /* Cache sizes from cpuid(4) */
	unsigned int l2_id = 0, l3_id = 0, num_threads_sharing, index_msb;
	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(c->cpu_index);

	if (c->cpuid_level > 3) {
		/*
		 * There should be at least one leaf. A non-zero value means
		 * that the number of leaves has been initialized.
		 */
		if (!ci->num_leaves)
			ci->num_leaves = find_num_cache_leaves(c);

		/*
		 * Whenever possible use cpuid(4), deterministic cache
		 * parameters cpuid leaf to find the cache details
		 */
		for (i = 0; i < ci->num_leaves; i++) {
			struct _cpuid4_info_regs id4 = {};
			int retval;

			retval = cpuid4_cache_lookup_regs(i, &id4, NULL);
			if (retval < 0)
				continue;

			switch (id4.eax.split.level) {
			case 1:
				if (id4.eax.split.type == CTYPE_DATA)
					new_l1d = id4.size/1024;
				else if (id4.eax.split.type == CTYPE_INST)
					new_l1i = id4.size/1024;
				break;
			case 2:
				new_l2 = id4.size/1024;
				num_threads_sharing = 1 + id4.eax.split.num_threads_sharing;
				index_msb = get_count_order(num_threads_sharing);
				l2_id = c->topo.apicid & ~((1 << index_msb) - 1);
				break;
			case 3:
				new_l3 = id4.size/1024;
				num_threads_sharing = 1 + id4.eax.split.num_threads_sharing;
				index_msb = get_count_order(num_threads_sharing);
				l3_id = c->topo.apicid & ~((1 << index_msb) - 1);
				break;
			default:
				break;
			}
		}
	}

	/* Don't use CPUID(2) if CPUID(4) is supported. */
	if (!ci->num_leaves && c->cpuid_level > 1) {
		const struct _cache_table *entry;
		union leaf_0x2_regs regs;
		u8 *desc;

		cpuid_get_leaf_0x2_regs(&regs);
		for_each_leaf_0x2_desc(regs, desc) {
			entry = cache_table_get(*desc);
			if (!entry)
				continue;

			switch (entry->cache_type) {
			case LVL_1_INST: l1i += entry->size; break;
			case LVL_1_DATA: l1d += entry->size; break;
			case LVL_2:	 l2  += entry->size; break;
			case LVL_3:	 l3  += entry->size; break;
			}
		}
	}

	if (new_l1d)
		l1d = new_l1d;

	if (new_l1i)
		l1i = new_l1i;

	if (new_l2) {
		l2 = new_l2;
		c->topo.llc_id = l2_id;
		c->topo.l2c_id = l2_id;
	}

	if (new_l3) {
		l3 = new_l3;
		c->topo.llc_id = l3_id;
	}

	/*
	 * If llc_id is not yet set, this means cpuid_level < 4 which in
	 * turns means that the only possibility is SMT (as indicated in
	 * cpuid1). Since cpuid2 doesn't specify shared caches, and we know
	 * that SMT shares all caches, we can unconditionally set cpu_llc_id to
	 * c->topo.pkg_id.
	 */
	if (c->topo.llc_id == BAD_APICID)
		c->topo.llc_id = c->topo.pkg_id;

	c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));

	if (!l2)
		cpu_detect_cache_sizes(c);
}

static int __cache_amd_cpumap_setup(unsigned int cpu, int index,
				    const struct _cpuid4_info_regs *id4)
{
	struct cpu_cacheinfo *this_cpu_ci;
	struct cacheinfo *ci;
	int i, sibling;

	/*
	 * For L3, always use the pre-calculated cpu_llc_shared_mask
	 * to derive shared_cpu_map.
	 */
	if (index == 3) {
		for_each_cpu(i, cpu_llc_shared_mask(cpu)) {
			this_cpu_ci = get_cpu_cacheinfo(i);
			if (!this_cpu_ci->info_list)
				continue;
			ci = this_cpu_ci->info_list + index;
			for_each_cpu(sibling, cpu_llc_shared_mask(cpu)) {
				if (!cpu_online(sibling))
					continue;
				cpumask_set_cpu(sibling,
						&ci->shared_cpu_map);
			}
		}
	} else if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
		unsigned int apicid, nshared, first, last;

		nshared = id4->eax.split.num_threads_sharing + 1;
		apicid = cpu_data(cpu).topo.apicid;
		first = apicid - (apicid % nshared);
		last = first + nshared - 1;

		for_each_online_cpu(i) {
			this_cpu_ci = get_cpu_cacheinfo(i);
			if (!this_cpu_ci->info_list)
				continue;

			apicid = cpu_data(i).topo.apicid;
			if ((apicid < first) || (apicid > last))
				continue;

			ci = this_cpu_ci->info_list + index;

			for_each_online_cpu(sibling) {
				apicid = cpu_data(sibling).topo.apicid;
				if ((apicid < first) || (apicid > last))
					continue;
				cpumask_set_cpu(sibling,
						&ci->shared_cpu_map);
			}
		}
	} else
		return 0;

	return 1;
}

static void __cache_cpumap_setup(unsigned int cpu, int index,
				 const struct _cpuid4_info_regs *id4)
{
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	struct cacheinfo *ci, *sibling_ci;
	unsigned long num_threads_sharing;
	int index_msb, i;
	struct cpuinfo_x86 *c = &cpu_data(cpu);

	if (c->x86_vendor == X86_VENDOR_AMD ||
	    c->x86_vendor == X86_VENDOR_HYGON) {
		if (__cache_amd_cpumap_setup(cpu, index, id4))
			return;
	}

	ci = this_cpu_ci->info_list + index;
	num_threads_sharing = 1 + id4->eax.split.num_threads_sharing;

	cpumask_set_cpu(cpu, &ci->shared_cpu_map);
	if (num_threads_sharing == 1)
		return;

	index_msb = get_count_order(num_threads_sharing);

	for_each_online_cpu(i)
		if (cpu_data(i).topo.apicid >> index_msb == c->topo.apicid >> index_msb) {
			struct cpu_cacheinfo *sib_cpu_ci = get_cpu_cacheinfo(i);

			if (i == cpu || !sib_cpu_ci->info_list)
				continue;/* skip if itself or no cacheinfo */
			sibling_ci = sib_cpu_ci->info_list + index;
			cpumask_set_cpu(i, &ci->shared_cpu_map);
			cpumask_set_cpu(cpu, &sibling_ci->shared_cpu_map);
		}
}

static void ci_info_init(struct cacheinfo *ci, const struct _cpuid4_info_regs *id4,
			 struct amd_northbridge *nb)
{
	ci->id				= id4->id;
	ci->attributes			= CACHE_ID;
	ci->level			= id4->eax.split.level;
	ci->type			= cache_type_map[id4->eax.split.type];
	ci->coherency_line_size		= id4->ebx.split.coherency_line_size + 1;
	ci->ways_of_associativity	= id4->ebx.split.ways_of_associativity + 1;
	ci->size			= id4->size;
	ci->number_of_sets		= id4->ecx.split.number_of_sets + 1;
	ci->physical_line_partition	= id4->ebx.split.physical_line_partition + 1;
	ci->priv			= nb;
}

int init_cache_level(unsigned int cpu)
{
	struct cpu_cacheinfo *ci = get_cpu_cacheinfo(cpu);

	/* There should be at least one leaf. */
	if (!ci->num_leaves)
		return -ENOENT;

	return 0;
}

/*
 * The max shared threads number comes from CPUID.4:EAX[25-14] with input
 * ECX as cache index. Then right shift apicid by the number's order to get
 * cache id for this cache node.
 */
static void get_cache_id(int cpu, struct _cpuid4_info_regs *id4)
{
	struct cpuinfo_x86 *c = &cpu_data(cpu);
	unsigned long num_threads_sharing;
	int index_msb;

	num_threads_sharing = 1 + id4->eax.split.num_threads_sharing;
	index_msb = get_count_order(num_threads_sharing);
	id4->id = c->topo.apicid >> index_msb;
}

int populate_cache_leaves(unsigned int cpu)
{
	unsigned int idx, ret;
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	struct cacheinfo *ci = this_cpu_ci->info_list;
	struct _cpuid4_info_regs id4 = {};
	struct amd_northbridge *nb;

	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
		ret = cpuid4_cache_lookup_regs(idx, &id4, &nb);
		if (ret)
			return ret;
		get_cache_id(cpu, &id4);
		ci_info_init(ci++, &id4, nb);
		__cache_cpumap_setup(cpu, idx, &id4);
	}
	this_cpu_ci->cpu_map_populated = true;

	return 0;
}

/*
 * Disable and enable caches. Needed for changing MTRRs and the PAT MSR.
 *
 * Since we are disabling the cache don't allow any interrupts,
 * they would run extremely slow and would only increase the pain.
 *
 * The caller must ensure that local interrupts are disabled and
 * are reenabled after cache_enable() has been called.
 */
static unsigned long saved_cr4;
static DEFINE_RAW_SPINLOCK(cache_disable_lock);

void cache_disable(void) __acquires(cache_disable_lock)
{
	unsigned long cr0;

	/*
	 * Note that this is not ideal
	 * since the cache is only flushed/disabled for this CPU while the
	 * MTRRs are changed, but changing this requires more invasive
	 * changes to the way the kernel boots
	 */

	raw_spin_lock(&cache_disable_lock);

	/* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
	cr0 = read_cr0() | X86_CR0_CD;
	write_cr0(cr0);

	/*
	 * Cache flushing is the most time-consuming step when programming
	 * the MTRRs. Fortunately, as per the Intel Software Development
	 * Manual, we can skip it if the processor supports cache self-
	 * snooping.
	 */
	if (!static_cpu_has(X86_FEATURE_SELFSNOOP))
		wbinvd();

	/* Save value of CR4 and clear Page Global Enable (bit 7) */
	if (cpu_feature_enabled(X86_FEATURE_PGE)) {
		saved_cr4 = __read_cr4();
		__write_cr4(saved_cr4 & ~X86_CR4_PGE);
	}

	/* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */
	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
	flush_tlb_local();

	if (cpu_feature_enabled(X86_FEATURE_MTRR))
		mtrr_disable();

	/* Again, only flush caches if we have to. */
	if (!static_cpu_has(X86_FEATURE_SELFSNOOP))
		wbinvd();
}

void cache_enable(void) __releases(cache_disable_lock)
{
	/* Flush TLBs (no need to flush caches - they are disabled) */
	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
	flush_tlb_local();

	if (cpu_feature_enabled(X86_FEATURE_MTRR))
		mtrr_enable();

	/* Enable caches */
	write_cr0(read_cr0() & ~X86_CR0_CD);

	/* Restore value of CR4 */
	if (cpu_feature_enabled(X86_FEATURE_PGE))
		__write_cr4(saved_cr4);

	raw_spin_unlock(&cache_disable_lock);
}

static void cache_cpu_init(void)
{
	unsigned long flags;

	local_irq_save(flags);

	if (memory_caching_control & CACHE_MTRR) {
		cache_disable();
		mtrr_generic_set_state();
		cache_enable();
	}

	if (memory_caching_control & CACHE_PAT)
		pat_cpu_init();

	local_irq_restore(flags);
}

static bool cache_aps_delayed_init = true;

void set_cache_aps_delayed_init(bool val)
{
	cache_aps_delayed_init = val;
}

bool get_cache_aps_delayed_init(void)
{
	return cache_aps_delayed_init;
}

static int cache_rendezvous_handler(void *unused)
{
	if (get_cache_aps_delayed_init() || !cpu_online(smp_processor_id()))
		cache_cpu_init();

	return 0;
}

void __init cache_bp_init(void)
{
	mtrr_bp_init();
	pat_bp_init();

	if (memory_caching_control)
		cache_cpu_init();
}

void cache_bp_restore(void)
{
	if (memory_caching_control)
		cache_cpu_init();
}

static int cache_ap_online(unsigned int cpu)
{
	cpumask_set_cpu(cpu, cpu_cacheinfo_mask);

	if (!memory_caching_control || get_cache_aps_delayed_init())
		return 0;

	/*
	 * Ideally we should hold mtrr_mutex here to avoid MTRR entries
	 * changed, but this routine will be called in CPU boot time,
	 * holding the lock breaks it.
	 *
	 * This routine is called in two cases:
	 *
	 *   1. very early time of software resume, when there absolutely
	 *      isn't MTRR entry changes;
	 *
	 *   2. CPU hotadd time. We let mtrr_add/del_page hold cpuhotplug
	 *      lock to prevent MTRR entry changes
	 */
	stop_machine_from_inactive_cpu(cache_rendezvous_handler, NULL,
				       cpu_cacheinfo_mask);

	return 0;
}

static int cache_ap_offline(unsigned int cpu)
{
	cpumask_clear_cpu(cpu, cpu_cacheinfo_mask);
	return 0;
}

/*
 * Delayed cache initialization for all AP's
 */
void cache_aps_init(void)
{
	if (!memory_caching_control || !get_cache_aps_delayed_init())
		return;

	stop_machine(cache_rendezvous_handler, NULL, cpu_online_mask);
	set_cache_aps_delayed_init(false);
}

static int __init cache_ap_register(void)
{
	zalloc_cpumask_var(&cpu_cacheinfo_mask, GFP_KERNEL);
	cpumask_set_cpu(smp_processor_id(), cpu_cacheinfo_mask);

	cpuhp_setup_state_nocalls(CPUHP_AP_CACHECTRL_STARTING,
				  "x86/cachectrl:starting",
				  cache_ap_online, cache_ap_offline);
	return 0;
}
early_initcall(cache_ap_register);