On AMD processors supporting X86_FEATURE_TOPOEXT set the l2c_id using the
Extended APIC ID and the Cache Properties CPUID.
Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
arch/x86/include/asm/cacheinfo.h | 1 +
arch/x86/kernel/cpu/amd.c | 1 +
arch/x86/kernel/cpu/cacheinfo.c | 36 ++++++++++++++++++++++++++++++++
3 files changed, 38 insertions(+)
diff --git a/arch/x86/include/asm/cacheinfo.h b/arch/x86/include/asm/cacheinfo.h
index ce9685fc78d8..5e472fc364c8 100644
--- a/arch/x86/include/asm/cacheinfo.h
+++ b/arch/x86/include/asm/cacheinfo.h
@@ -7,6 +7,7 @@ extern unsigned int memory_caching_control;
#define CACHE_MTRR 0x01
#define CACHE_PAT 0x02
+void cacheinfo_amd_init_l2c_id(struct cpuinfo_x86 *c, int cpu);
void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, int cpu);
void cacheinfo_hygon_init_llc_id(struct cpuinfo_x86 *c, int cpu);
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f769d6d08b43..e68d31231666 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -358,6 +358,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
if (!err)
c->x86_coreid_bits = get_count_order(c->x86_max_cores);
+ cacheinfo_amd_init_l2c_id(c, cpu);
cacheinfo_amd_init_llc_id(c, cpu);
} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index f4e5aa27eec6..0baf2d9b1595 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -659,6 +659,42 @@ static int find_num_cache_leaves(struct cpuinfo_x86 *c)
return i;
}
+void cacheinfo_amd_init_l2c_id(struct cpuinfo_x86 *c, int cpu)
+{
+ u32 eax, ebx, ecx, edx, num_sharing_cache;
+ int i = 0, bits;
+
+ /* Check if L2 cache identifiers exists. */
+ if (!cpuid_ecx(0x80000006))
+ return;
+
+ while (true) {
+ u32 level;
+
+ cpuid_count(0x8000001d, i, &eax, &ebx, &ecx, &edx);
+ if (!eax)
+ return;
+
+ /*
+ * Check if the current leaf is for L2 cache using
+ * eax[7:5] used to describe the cache level.
+ */
+ level = (eax >> 5) & 0x7;
+ if (level == 2)
+ break;
+
+ ++i;
+ }
+
+ /*
+ * L2 ID is calculated from the number of threads
+ * sharing the L2 cache.
+ */
+ num_sharing_cache = ((eax >> 14) & 0xfff) + 1;
+ bits = get_count_order(num_sharing_cache);
+ per_cpu(cpu_l2c_id, cpu) = c->apicid >> bits;
+}
+
void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, int cpu)
{
/*
--
2.34.1
