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    Subject[PATCH 4.9 153/223] perf/events/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.

    Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
    Signed-off-by: Borislav Petkov <bp@suse.de>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
    Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
    Link: http://lkml.kernel.org/r/1524864877-111962-3-git-send-email-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 10f023799f11..c16c99bc2a10 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
    @@ -377,26 +378,8 @@ 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;
    --
    2.20.1


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