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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>
This commit is contained in:
Andreas Herrmann 2009-11-11 20:03:29 +01:00 committed by Ingo Molnar
parent 1a74357066
commit 9f15226e75
1 changed files with 1 additions and 1 deletions
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2
arch/x86/kernel/microcode_core.c
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@ -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);