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)
Signed-off-by: Andi Kleen <[email protected]>
---
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 <[email protected]>: Work with CPU hotplug infrastructure.
+ * Andi Kleen : CPUID4 emulation on AMD.
*/
#include <linux/init.h>
@@ -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
@@ -1071,6 +1071,9 @@ 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
@@ -112,6 +112,7 @@ 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
@@ -96,6 +96,7 @@ 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)
-
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