x86/cpu/AMD: Evaluate smp_num_siblings early (1e1d7e25) · Commits · 戴 / test

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>

arch/x86/kernel/cpu/amd.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -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)

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