4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
