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Subject[PATCH 2/4] perf/x86/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id
Date
Current logic iterates over CPUID Fn8000001d leafs (Cache Properties)
to detect the last level cache, and derive the last-level cache ID.
However, this information is already available in the cpu_llc_id.
Therefore, make use of it instead.

Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
arch/x86/events/amd/uncore.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index f5cbbba..981ba5e 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -19,6 +19,7 @@
#include <asm/cpufeature.h>
#include <asm/perf_event.h>
#include <asm/msr.h>
+#include <asm/smp.h>

#define NUM_COUNTERS_NB 4
#define NUM_COUNTERS_L2 4
@@ -399,26 +400,8 @@ static int amd_uncore_cpu_starting(unsigned int cpu)
}

if (amd_uncore_llc) {
- unsigned int apicid = cpu_data(cpu).apicid;
- unsigned int nshared, subleaf, prev_eax = 0;
-
uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
- /*
- * Iterate over Cache Topology Definition leaves until no
- * more cache descriptions are available.
- */
- for (subleaf = 0; subleaf < 5; subleaf++) {
- cpuid_count(0x8000001d, subleaf, &eax, &ebx, &ecx, &edx);
-
- /* EAX[0:4] gives type of cache */
- if (!(eax & 0x1f))
- break;
-
- prev_eax = eax;
- }
- nshared = ((prev_eax >> 14) & 0xfff) + 1;
-
- uncore->id = apicid - (apicid % nshared);
+ uncore->id = per_cpu(cpu_llc_id, cpu);

uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
*per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
--
2.7.4
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