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Subject[PATCH 12/17] x86/microcode/intel: Use *wrmsrl variants
Date
From: Borislav Petkov <bp@suse.de>

... and drop the 32-bit casting games which we had to do at the time
because wrmsr() was unforgiving then, see c3fd0bd5e19a from the
full history tree:

commit c3fd0bd5e19aaff9cdd104edff136a2023db657e
Author: Linus Torvalds <torvalds@home.osdl.org>
Date: Tue Feb 17 23:23:41 2004 -0800

Fix up the microcode update on regular 32-bit x86. Our wrmsr()
is a bit unforgiving and really doesn't like 64-bit values.
...

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/microcode/intel.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 35186a0dd5fc..ff0b44951d12 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -370,7 +370,7 @@ static int collect_cpu_info_early(struct ucode_cpu_info *uci)
native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
csig.pf = 1 << ((val[1] >> 18) & 7);
}
- native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+ native_wrmsrl(MSR_IA32_UCODE_REV, 0);

/* As documented in the SDM: Do a CPUID 1 here */
sync_core();
@@ -648,10 +648,8 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
return 0;

/* write microcode via MSR 0x79 */
- native_wrmsr(MSR_IA32_UCODE_WRITE,
- (unsigned long)mc->bits,
- (unsigned long)mc->bits >> 16 >> 16);
- native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+ native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
+ native_wrmsrl(MSR_IA32_UCODE_REV, 0);

/* As documented in the SDM: Do a CPUID 1 here */
sync_core();
@@ -860,10 +858,8 @@ static int apply_microcode_intel(int cpu)
return 0;

/* write microcode via MSR 0x79 */
- wrmsr(MSR_IA32_UCODE_WRITE,
- (unsigned long) mc->bits,
- (unsigned long) mc->bits >> 16 >> 16);
- wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+ wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
+ wrmsrl(MSR_IA32_UCODE_REV, 0);

/* As documented in the SDM: Do a CPUID 1 here */
sync_core();
--
2.3.5
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