4.18-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/cpu/amd.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- 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 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 @@ -683,6 +694,8 @@ static void early_init_amd(struct cpuinf 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)