From 9f15226e75583547aaf542c6be4bdac1060dd425 Mon Sep 17 00:00:00 2001
From: Andreas Herrmann <herrmann.der.user@googlemail.com>
Date: Wed, 11 Nov 2009 20:03:29 +0100
Subject: [PATCH] x86, ucode-amd: Ensure ucode update on suspend/resume after
CPU off/online cycle
When switching a CPU offline/online and then doing
suspend/resume, ucode is not updated on this CPU.
This is due to the microcode_fini_cpu() call which frees uci->mc
when setting the CPU offline:
static void microcode_fini_cpu_amd(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
vfree(uci->mc);
uci->mc = NULL;
}
When the CPU is set online uci->mc is still NULL because no
ucode update is required.
Finally this prevents ucode update when resuming after suspend:
static enum ucode_state microcode_resume_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
if (!uci->mc)
return UCODE_NFOUND;
...
}
Fix is to check whether uci->mc is valid before
microcode_resume_cpu() is called.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: dimm <dmitry.adamushko@gmail.com>
LKML-Reference: <20091111190329.GF18592@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/microcode_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index d2a816021d9f..adf234061540 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -393,7 +393,7 @@ static enum ucode_state microcode_update_cpu(int cpu)
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
enum ucode_state ustate;
- if (uci->valid)
+ if (uci->valid && uci->mc)
ustate = microcode_resume_cpu(cpu);
else
ustate = microcode_init_cpu(cpu);
--
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