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authorBorislav Petkov <bp@suse.de>2015-10-12 12:22:41 +0300
committerIngo Molnar <mingo@kernel.org>2015-10-12 17:15:48 +0300
commit2eff73c0a11f19ff082a566e3429fbaaca7b8e7b (patch)
tree10555b4a753a5c353a505803946db2c5ac071104 /arch/x86/include/asm/microcode_amd.h
parentfa20a2ed6fff717839ec03b6574ea0affcb58841 (diff)
downloadlinux-2eff73c0a11f19ff082a566e3429fbaaca7b8e7b.tar.xz
x86/microcode/amd: Extract current patch level read to a function
Pave the way for checking the current patch level of the microcode in a core. We want to be able to do stuff depending on the patch level - in this case decide whether to update or not. But that will be added in a later patch. Drop unused local var uci assignment, while at it. Integrate a fix for 32-bit and CONFIG_PARAVIRT from Takashi Iwai: Use native_rdmsr() in check_current_patch_level() because with CONFIG_PARAVIRT enabled and on 32-bit, where we run before paging has been enabled, we cannot deref pv_info yet. Or we could, but we'd need to access its physical address. This way of fixing it is simpler. See: https://bugzilla.suse.com/show_bug.cgi?id=943179 for the background. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Takashi Iwai <tiwai@suse.com>: Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/1444641762-9437-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/microcode_amd.h')
-rw-r--r--arch/x86/include/asm/microcode_amd.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index ac6d328977a6..9b214e10d499 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -76,4 +76,5 @@ static inline int __init save_microcode_in_initrd_amd(void) { return -EINVAL; }
void reload_ucode_amd(void) {}
#endif
+extern bool check_current_patch_level(u32 *rev);
#endif /* _ASM_X86_MICROCODE_AMD_H */