[tip:x86/microcode] x86/microcode: Collect CPU info on resume

[tip-bot for Borislav Petkov]

Commit-ID:  7f709d0c322203e37581f6b7c91f88b4fdeca5a0
Gitweb:     http://git.kernel.org/tip/7f709d0c322203e37581f6b7c91f88b4fdeca5a0
Author:     Borislav Petkov <bp@xxxxxxx>
AuthorDate: Tue, 25 Oct 2016 11:55:18 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 25 Oct 2016 12:28:58 +0200

x86/microcode: Collect CPU info on resume

We need to reread the CPU's microcode revision after resume because
applied microcode gets "forgotten" depending on the sleep state.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20161025095522.11964-9-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/microcode/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index a18ff75..f737039 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -498,6 +498,9 @@ static enum ucode_state microcode_update_cpu(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 
+	/* Refresh CPU microcode revision after resume. */
+	collect_cpu_info(cpu);
+
 	if (uci->valid)
 		return microcode_resume_cpu(cpu);