lkml.org 
[lkml]   [2009]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/microcode] x86, ucode-amd: Ensure ucode update on suspend/resume after CPU off/online cycle
Commit-ID:  9f15226e75583547aaf542c6be4bdac1060dd425
Gitweb: http://git.kernel.org/tip/9f15226e75583547aaf542c6be4bdac1060dd425
Author: Andreas Herrmann <herrmann.der.user@googlemail.com>
AuthorDate: Wed, 11 Nov 2009 20:03:29 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 11 Nov 2009 20:06:54 +0100

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 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index d2a8160..adf2340 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);

\
 
 \ /
  Last update: 2009-11-11 20:13    [W:0.031 / U:0.280 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site