[tip:x86/microcode] x86, microcode, AMD: Read CPUID(1).EAX on the correct cpu

From: tip-bot for Borislav Petkov
Date: Wed Aug 22 2012 - 19:43:22 EST


Commit-ID: 5f5b747282c6cc57b91baba37f76de27398b9e60
Gitweb: http://git.kernel.org/tip/5f5b747282c6cc57b91baba37f76de27398b9e60
Author: Borislav Petkov <borislav.petkov@xxxxxxx>
AuthorDate: Wed, 25 Jul 2012 20:06:54 +0200
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Wed, 22 Aug 2012 16:15:50 -0700

x86, microcode, AMD: Read CPUID(1).EAX on the correct cpu

Read the CPUID(1).EAX leaf at the correct cpu and use it to search the
equivalence table for matching microcode patch. No functionality change.

Signed-off-by: Borislav Petkov <borislav.petkov@xxxxxxx>
Link: http://lkml.kernel.org/r/1344361461-10076-9-git-send-email-bp@xxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/microcode_amd.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index 8fdf7d9..25d34b1 100644
--- a/arch/x86/kernel/microcode_amd.c
+++ b/arch/x86/kernel/microcode_amd.c
@@ -82,6 +82,7 @@ static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);

+ csig->sig = cpuid_eax(0x00000001);
csig->rev = c->microcode;
pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev);

@@ -118,16 +119,15 @@ static unsigned int verify_ucode_size(int cpu, u32 patch_size,
return patch_size;
}

-static u16 find_equiv_id(void)
+static u16 find_equiv_id(unsigned int cpu)
{
- unsigned int current_cpu_id, i = 0;
+ struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
+ int i = 0;

BUG_ON(equiv_cpu_table == NULL);

- current_cpu_id = cpuid_eax(0x00000001);
-
while (equiv_cpu_table[i].installed_cpu != 0) {
- if (current_cpu_id == equiv_cpu_table[i].installed_cpu)
+ if (uci->cpu_sig.sig == equiv_cpu_table[i].installed_cpu)
return equiv_cpu_table[i].equiv_cpu;

i++;
@@ -150,7 +150,7 @@ static int get_matching_microcode(int cpu, const u8 *ucode_ptr,
patch_size = *(u32 *)(ucode_ptr + 4);
*current_size = patch_size + SECTION_HDR_SIZE;

- equiv_cpu_id = find_equiv_id();
+ equiv_cpu_id = find_equiv_id(cpu);
if (!equiv_cpu_id)
return 0;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/