Merge tag 'x86_microcode_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 microcode loader update from Borislav Petkov:

 - Remove the unconditional cache writeback and invalidation after
   loading the microcode patch on Intel as this was addressing a
   microcode bug for which there is a concrete microcode revision check
   instead

* tag 'x86_microcode_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/intel: Remove unnecessary cache writeback and invalidation

1 files changed, 2 insertions, 8 deletions

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 815fa67356a2..f3d534807d91 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -319,12 +319,6 @@ static enum ucode_state __apply_microcode(struct ucode_cpu_info *uci,
 		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 */
 	native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
 
@@ -574,14 +568,14 @@ static bool is_blacklisted(unsigned int cpu)
 	/*
 	 * Late loading on model 79 with microcode revision less than 0x0b000021
 	 * and LLC size per core bigger than 2.5MB may result in a system hang.
-	 * This behavior is documented in item BDF90, #334165 (Intel Xeon
+	 * This behavior is documented in item BDX90, #334165 (Intel Xeon
 	 * Processor E7-8800/4800 v4 Product Family).
 	 */
 	if (c->x86_vfm == INTEL_BROADWELL_X &&
 	    c->x86_stepping == 0x01 &&
 	    llc_size_per_core > 2621440 &&
 	    c->microcode < 0x0b000021) {
-		pr_err_once("Erratum BDF90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
+		pr_err_once("Erratum BDX90: late loading with revision < 0x0b000021 (0x%x) disabled.\n", c->microcode);
 		pr_err_once("Please consider either early loading through initrd/built-in or a potential BIOS update.\n");
 		return true;
 	}