From: Borislav Petkov <[email protected]> 8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id") broke the initial strategy for Bulldozer-based cores' topology, where we consider each thread of a compute unit a standalone core and not a HT or SMT thread.
Revert to the firmware-supplied core_id numbering and do not make them thread siblings as we don't consider them for such even if they technically are, more or less. Reported-and-tested-by: Brice Goglin <[email protected]> Tested-by: Yazen Ghannam <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: <[email protected]> # v4.6.. Fixes: 8196dab4fc15 ("x86/cpu: Get rid of compute_unit_id") --- arch/x86/kernel/cpu/amd.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 71cae73a5076..1d3167269a67 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -309,15 +309,8 @@ static void amd_get_topology(struct cpuinfo_x86 *c) /* get information required for multi-node processors */ if (boot_cpu_has(X86_FEATURE_TOPOEXT)) { - u32 eax, ebx, ecx, edx; - cpuid(0x8000001e, &eax, &ebx, &ecx, &edx); - node_id = ecx & 7; - - /* get compute unit information */ - smp_num_siblings = ((ebx >> 8) & 3) + 1; - c->x86_max_cores /= smp_num_siblings; - c->cpu_core_id = ebx & 0xff; + node_id = cpuid_ecx(0x8000001e) & 7; /* * We may have multiple LLCs if L3 caches exist, so check if we -- 2.11.0
