summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/cpu/amd.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2018-06-06 00:57:38 +0200
committerThomas Gleixner <tglx@linutronix.de>2018-06-21 14:21:00 +0200
commit1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c (patch)
treeba708b01907016278ad4a2800742c828d5759451 /arch/x86/kernel/cpu/amd.c
parent119bff8a9c9bb00116a844ec68be7bc4b1c768f5 (diff)
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.c13
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)