i386/x86-64: Emulate CPUID4 on AMD Intel systems report the cache level data from CPUID 4 in sysfs. Add a CPUID 4 emulation for AMD CPUs to report the same information for them. This allows programs to read this information in a uniform way. The AMD way to report this is less flexible so some assumptions are hardcoded (e.g. no L3) TBD no errata checks for K7 broken cache sizes right now. Signed-off-by: Andi Kleen --- arch/i386/kernel/cpu/amd.c | 2 arch/i386/kernel/cpu/intel_cacheinfo.c | 113 +++++++++++++++++++++++++++++---- arch/x86_64/kernel/setup.c | 3 include/asm-i386/processor.h | 1 include/asm-x86_64/processor.h | 1 5 files changed, 107 insertions(+), 13 deletions(-) Index: linux/arch/i386/kernel/cpu/intel_cacheinfo.c =================================================================== --- linux.orig/arch/i386/kernel/cpu/intel_cacheinfo.c +++ linux/arch/i386/kernel/cpu/intel_cacheinfo.c @@ -4,6 +4,7 @@ * Changes: * Venkatesh Pallipadi : Adding cache identification through cpuid(4) * Ashok Raj : Work with CPU hotplug infrastructure. + * Andi Kleen : CPUID4 emulation on AMD. */ #include @@ -130,25 +131,111 @@ struct _cpuid4_info { cpumask_t shared_cpu_map; }; -static unsigned short num_cache_leaves; +unsigned short num_cache_leaves; + +/* AMD doesn't have CPUID4. Emulate it here to report the same + information to the user. This makes some assumptions about the machine: + No L3, 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; +}; + +static unsigned short assocs[] = { + [1] = 1, [2] = 2, [4] = 4, [6] = 8, + [8] = 16, + [0xf] = 0xffff // ?? + }; +static unsigned char levels[] = { 1, 1, 2 }; +static unsigned char types[] = { 1, 2, 3 }; + +static void __cpuinit amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax, + union _cpuid4_leaf_ebx *ebx, + union _cpuid4_leaf_ecx *ecx) +{ + unsigned dummy; + unsigned line_size, lines_per_tag, assoc, size_in_kb; + union l1_cache l1i, l1d; + union l2_cache l2; + + eax->full = 0; + ebx->full = 0; + ecx->full = 0; + + cpuid(0x80000005, &dummy, &dummy, &l1d.val, &l1i.val); + cpuid(0x80000006, &dummy, &dummy, &l2.val, &dummy); + + if (leaf > 2 || !l1d.val || !l1i.val || !l2.val) + return; + + eax->split.is_self_initializing = 1; + eax->split.type = types[leaf]; + eax->split.level = levels[leaf]; + eax->split.num_threads_sharing = 0; + eax->split.num_cores_on_die = current_cpu_data.x86_max_cores - 1; + + if (leaf <= 1) { + union l1_cache *l1 = leaf == 0 ? &l1d : &l1i; + assoc = l1->assoc; + line_size = l1->line_size; + lines_per_tag = l1->lines_per_tag; + size_in_kb = l1->size_in_kb; + } else { + assoc = 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 = current_cpu_data.x86_cache_size; + } + + if (assoc == 0xf) + eax->split.is_fully_associative = 1; + ebx->split.coherency_line_size = line_size - 1; + ebx->split.ways_of_associativity = assocs[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; +} static int __cpuinit cpuid4_cache_lookup(int index, struct _cpuid4_info *this_leaf) { - unsigned int eax, ebx, ecx, edx; - union _cpuid4_leaf_eax cache_eax; + union _cpuid4_leaf_eax eax; + union _cpuid4_leaf_ebx ebx; + union _cpuid4_leaf_ecx ecx; + unsigned edx; - cpuid_count(4, index, &eax, &ebx, &ecx, &edx); - cache_eax.full = eax; - if (cache_eax.split.type == CACHE_TYPE_NULL) + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) + amd_cpuid4(index, &eax, &ebx, &ecx); + else + cpuid_count(4, index, &eax.full, &ebx.full, &ecx.full, &edx); + if (eax.split.type == CACHE_TYPE_NULL) return -EIO; /* better error ? */ - this_leaf->eax.full = eax; - this_leaf->ebx.full = ebx; - this_leaf->ecx.full = ecx; - this_leaf->size = (this_leaf->ecx.split.number_of_sets + 1) * - (this_leaf->ebx.split.coherency_line_size + 1) * - (this_leaf->ebx.split.physical_line_partition + 1) * - (this_leaf->ebx.split.ways_of_associativity + 1); + this_leaf->eax = eax; + this_leaf->ebx = ebx; + this_leaf->ecx = ecx; + this_leaf->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; } Index: linux/arch/x86_64/kernel/setup.c =================================================================== --- linux.orig/arch/x86_64/kernel/setup.c +++ linux/arch/x86_64/kernel/setup.c @@ -976,6 +976,9 @@ static int __init init_amd(struct cpuinf if (c->extended_cpuid_level >= 0x80000008) amd_detect_cmp(c); + /* Fix cpuid4 emulation for more */ + num_cache_leaves = 3; + return r; } Index: linux/include/asm-i386/processor.h =================================================================== --- linux.orig/include/asm-i386/processor.h +++ linux/include/asm-i386/processor.h @@ -113,6 +113,7 @@ extern char ignore_fpu_irq; extern void identify_cpu(struct cpuinfo_x86 *); extern void print_cpu_info(struct cpuinfo_x86 *); extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c); +extern unsigned short num_cache_leaves; #ifdef CONFIG_X86_HT extern void detect_ht(struct cpuinfo_x86 *c); Index: linux/include/asm-x86_64/processor.h =================================================================== --- linux.orig/include/asm-x86_64/processor.h +++ linux/include/asm-x86_64/processor.h @@ -97,6 +97,7 @@ extern char ignore_irq13; extern void identify_cpu(struct cpuinfo_x86 *); extern void print_cpu_info(struct cpuinfo_x86 *); extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c); +extern unsigned short num_cache_leaves; /* * EFLAGS bits Index: linux/arch/i386/kernel/cpu/amd.c =================================================================== --- linux.orig/arch/i386/kernel/cpu/amd.c +++ linux/arch/i386/kernel/cpu/amd.c @@ -242,6 +242,8 @@ static void __init init_amd(struct cpuin } #endif + if (cpuid_eax(0x80000000) >= 0x80000006) + num_cache_leaves = 3; } static unsigned int amd_size_cache(struct cpuinfo_x86 * c, unsigned int size)