[PATCH v8 26/38] x86/CPU/AMD: Make the microcode level available earlier in the boot

Tom Lendacky
2017-06-27T15:00:45Z

Move the setting of the cpuinfo_x86.microcode field from amd_init() to
early_amd_init() so that it is available earlier in the boot process. This
avoids having to read MSR_AMD64_PATCH_LEVEL directly during early boot.

Reviewed-by: Borislav Petkov <bp-l3A5Bk7waGM@public.gmane.org>
Signed-off-by: Tom Lendacky <thomas.lendacky-5C7GfCeVMHo@public.gmane.org>
---
arch/x86/kernel/cpu/amd.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 5bdcbd4..fdcf305 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -547,8 +547,12 @@ static void bsp_init_amd(struct cpuinfo_x86 *c)

static void early_init_amd(struct cpuinfo_x86 *c)
{
+ u32 dummy;
+
early_init_amd_mc(c);

+ rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
+
/*
* c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
* with P/T states and does not stop in deep C-states
@@ -746,8 +750,6 @@ static void init_amd_bd(struct cpuinfo_x86 *c)

static void init_amd(struct cpuinfo_x86 *c)
{
- u32 dummy;
-
early_init_amd(c);

/*
@@ -809,8 +811,6 @@ static void init_amd(struct cpuinfo_x86 *c)
if (c->x86 > 0x11)
set_cpu_cap(c, X86_FEATURE_ARAT);

- rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
-
/* 3DNow or LM implies PREFETCHW */
if (!cpu_has(c, X86_FEATURE_3DNOWPREFETCH))
if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM))