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    Subject[PATCH resend] x86, amd: Get multi-node CPU info from NodeId MSR instead of PCI config space

    Use NodeId MSR to get NodeId and number of nodes per processor.

    Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
    ---
    arch/x86/include/asm/cpufeature.h | 1 +
    arch/x86/kernel/cpu/amd.c | 53 ++++++++++--------------------------
    2 files changed, 16 insertions(+), 38 deletions(-)

    diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
    index 9cfc88b..2cbf0a2 100644
    --- a/arch/x86/include/asm/cpufeature.h
    +++ b/arch/x86/include/asm/cpufeature.h
    @@ -153,6 +153,7 @@
    #define X86_FEATURE_SSE5 (6*32+11) /* SSE-5 */
    #define X86_FEATURE_SKINIT (6*32+12) /* SKINIT/STGI instructions */
    #define X86_FEATURE_WDT (6*32+13) /* Watchdog timer */
    +#define X86_FEATURE_NODEID_MSR (6*32+19) /* NodeId MSR */

    /*
    * Auxiliary flags: Linux defined - For features scattered in various
    diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
    index c910a71..85ee6c3 100644
    --- a/arch/x86/kernel/cpu/amd.c
    +++ b/arch/x86/kernel/cpu/amd.c
    @@ -254,59 +254,36 @@ static int __cpuinit nearby_node(int apicid)

    /*
    * Fixup core topology information for AMD multi-node processors.
    - * Assumption 1: Number of cores in each internal node is the same.
    - * Assumption 2: Mixed systems with both single-node and dual-node
    - * processors are not supported.
    + * Assumption: Number of cores in each internal node is the same.
    */
    #ifdef CONFIG_X86_HT
    static void __cpuinit amd_fixup_dcm(struct cpuinfo_x86 *c)
    {
    -#ifdef CONFIG_PCI
    - u32 t, cpn;
    - u8 n, n_id;
    + unsigned long long value;
    + u32 nodes, cores_per_node;
    int cpu = smp_processor_id();

    + if (!cpu_has(c, X86_FEATURE_NODEID_MSR))
    + return;
    +
    /* fixup topology information only once for a core */
    if (cpu_has(c, X86_FEATURE_AMD_DCM))
    return;

    - /* check for multi-node processor on boot cpu */
    - t = read_pci_config(0, 24, 3, 0xe8);
    - if (!(t & (1 << 29)))
    + rdmsrl(0xc001100c, value);
    +
    + nodes = ((value >> 3) & 7) + 1;
    + if (nodes == 1)
    return;

    set_cpu_cap(c, X86_FEATURE_AMD_DCM);
    + cores_per_node = c->x86_max_cores / nodes;

    - /* cores per node: each internal node has half the number of cores */
    - cpn = c->x86_max_cores >> 1;
    + /* store NodeID, use llc_shared_map to store sibling info */
    + per_cpu(cpu_llc_id, cpu) = value & 7;

    - /* even-numbered NB_id of this dual-node processor */
    - n = c->phys_proc_id << 1;
    -
    - /*
    - * determine internal node id and assign cores fifty-fifty to
    - * each node of the dual-node processor
    - */
    - t = read_pci_config(0, 24 + n, 3, 0xe8);
    - n = (t>>30) & 0x3;
    - if (n == 0) {
    - if (c->cpu_core_id < cpn)
    - n_id = 0;
    - else
    - n_id = 1;
    - } else {
    - if (c->cpu_core_id < cpn)
    - n_id = 1;
    - else
    - n_id = 0;
    - }
    -
    - /* compute entire NodeID, use llc_shared_map to store sibling info */
    - per_cpu(cpu_llc_id, cpu) = (c->phys_proc_id << 1) + n_id;
    -
    - /* fixup core id to be in range from 0 to cpn */
    - c->cpu_core_id = c->cpu_core_id % cpn;
    -#endif
    + /* fixup core id to be in range from 0 to (cores_per_node - 1) */
    + c->cpu_core_id = c->cpu_core_id % cores_per_node;
    }
    #endif

    --
    1.6.5


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