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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-06-06 00:57:38 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-06-21 14:21:00 +0200 |
| commit | 1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c (patch) | |
| tree | ba708b01907016278ad4a2800742c828d5759451 /arch/x86/kernel/cpu/amd.c | |
| parent | 119bff8a9c9bb00116a844ec68be7bc4b1c768f5 (diff) | |
| download | lwn-1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c.tar.gz lwn-1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c.zip | |
x86/cpu/AMD: Evaluate smp_num_siblings early
To support force disabling of SMT it's required to know the number of
thread siblings early. amd_get_topology() cannot be called before the APIC
driver is selected, so split out the part which initializes
smp_num_siblings and invoke it from amd_early_init().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/amd.c')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index d120e5cefca9..b20dee982a53 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -315,6 +315,17 @@ static void legacy_fixup_core_id(struct cpuinfo_x86 *c) c->cpu_core_id %= cus_per_node; } + +static void amd_get_topology_early(struct cpuinfo_x86 *c) +{ + if (boot_cpu_has(X86_FEATURE_TOPOEXT)) { + u32 eax, ebx, ecx, edx; + + cpuid(0x8000001e, &eax, &ebx, &ecx, &edx); + smp_num_siblings = ((ebx >> 8) & 0xff) + 1; + } +} + /* * Fixup core topology information for * (1) AMD multi-node processors @@ -681,6 +692,8 @@ static void early_init_amd(struct cpuinfo_x86 *c) set_cpu_bug(c, X86_BUG_AMD_E400); early_detect_mem_encrypt(c); + + amd_get_topology_early(c); } static void init_amd_k8(struct cpuinfo_x86 *c) |