From: Borislav Petkov <[email protected]> ... 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 <[email protected]> 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 <[email protected]> --- 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
