Commit 91df9fdf authored by Ashok Raj's avatar Ashok Raj Committed by Thomas Gleixner

x86/microcode/intel: Writeback and invalidate caches before updating microcode

Updating microcode is less error prone when caches have been flushed and
depending on what exactly the microcode is updating. For example, some
of the issues around certain Broadwell parts can be addressed by doing a
full cache flush.

[ Borislav: Massage it and use native_wbinvd() in both cases. ]
Signed-off-by: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Tested-by: default avatarAshok Raj <ashok.raj@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Link: http://lkml.kernel.org/r/1519352533-15992-3-git-send-email-ashok.raj@intel.com
Link: https://lkml.kernel.org/r/20180228102846.13447-4-bp@alien8.de
parent c182d2b7
...@@ -600,6 +600,12 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early) ...@@ -600,6 +600,12 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
return UCODE_OK; return UCODE_OK;
} }
/*
* Writeback and invalidate caches before updating microcode to avoid
* internal issues depending on what the microcode is updating.
*/
native_wbinvd();
/* write microcode via MSR 0x79 */ /* write microcode via MSR 0x79 */
native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits); native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
...@@ -816,6 +822,12 @@ static enum ucode_state apply_microcode_intel(int cpu) ...@@ -816,6 +822,12 @@ static enum ucode_state apply_microcode_intel(int cpu)
return UCODE_OK; return UCODE_OK;
} }
/*
* Writeback and invalidate caches before updating microcode to avoid
* internal issues depending on what the microcode is updating.
*/
native_wbinvd();
/* write microcode via MSR 0x79 */ /* write microcode via MSR 0x79 */
wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits); wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
......
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