[PATCH 2/4] x86, cacheinfo: Determine number of cache leafs usingCPUID 0x8000001d on AMD

From: Andreas Herrmann
Date: Fri Oct 19 2012 - 04:59:38 EST



CPUID 0x8000001d works quite similar to Intels' CPUID function 4.
Use it to determine number of cache leafs.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@xxxxxxx>
---
arch/x86/include/asm/processor.h | 2 +-
arch/x86/kernel/cpu/amd.c | 7 +------
arch/x86/kernel/cpu/intel_cacheinfo.c | 28 +++++++++++++++++++++++-----
3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index b98c0d9..4bfa500 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -187,7 +187,7 @@ extern void print_cpu_info(struct cpuinfo_x86 *);
void print_cpu_msr(struct cpuinfo_x86 *);
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
-extern unsigned short num_cache_leaves;
+extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);

extern void detect_extended_topology(struct cpuinfo_x86 *c);
extern void detect_ht(struct cpuinfo_x86 *c);
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 64e9ad4..a8538e6 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -643,12 +643,7 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
detect_ht(c);
#endif

- if (c->extended_cpuid_level >= 0x80000006) {
- if (cpuid_edx(0x80000006) & 0xf000)
- num_cache_leaves = 4;
- else
- num_cache_leaves = 3;
- }
+ init_amd_cacheinfo(c);

if (c->x86 >= 0xf)
set_cpu_cap(c, X86_FEATURE_K8);
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index 93c5451..8ce7a83 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -557,21 +557,39 @@ __cpuinit cpuid4_cache_lookup_regs(int index,
return 0;
}

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

+ if (c->x86_vendor == X86_VENDOR_AMD)
+ op = 0x8000001d;
+ else
+ op = 4;
+
do {
++i;
- /* Do cpuid(4) loop to find out num_cache_leaves */
- cpuid_count(4, i, &eax, &ebx, &ecx, &edx);
+ /* 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 != CACHE_TYPE_NULL);
return i;
}

+void __cpuinit init_amd_cacheinfo(struct cpuinfo_x86 *c)
+{
+
+ if (cpu_has_topoext) {
+ num_cache_leaves = find_num_cache_leaves(c);
+ } else if (c->extended_cpuid_level >= 0x80000006) {
+ if (cpuid_edx(0x80000006) & 0xf000)
+ num_cache_leaves = 4;
+ else
+ num_cache_leaves = 3;
+ }
+}
+
unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)
{
/* Cache sizes */
@@ -588,7 +606,7 @@ unsigned int __cpuinit init_intel_cacheinfo(struct cpuinfo_x86 *c)

if (is_initialized == 0) {
/* Init num_cache_leaves from boot CPU */
- num_cache_leaves = find_num_cache_leaves();
+ num_cache_leaves = find_num_cache_leaves(c);
is_initialized++;
}

--
1.7.8.6


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