x86/microcode: Rework early revisions reporting

The AMD side of the loader issues the microcode revision for each
logical thread on the system, which can become really noisy on huge
machines. And doing that doesn't make a whole lot of sense - the
microcode revision is already in /proc/cpuinfo.

So in case one is interested in the theoretical support of mixed silicon
steppings on AMD, one can check there.

What is also missing on the AMD side - something which people have
requested before - is showing the microcode revision the CPU had
*before* the early update.

So abstract that up in the main code and have the BSP on each vendor
provide those revision numbers.

Then, dump them only once on driver init.

On Intel, do not dump the patch date - it is not needed.

Reported-by: Linus Torvalds <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/r/CAHk-=wg=%[email protected]

1 files changed, 11 insertions, 28 deletions

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 9373ec01c5ae..13b45b9c806d 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -104,8 +104,6 @@ struct cont_desc {
 	size_t		     size;
 };
 
-static u32 ucode_new_rev;
-
 /*
  * Microcode patch container file is prepended to the initrd in cpio
  * format. See Documentation/arch/x86/microcode.rst
@@ -442,12 +440,11 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
  *
  * Returns true if container found (sets @desc), false otherwise.
  */
-static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size)
+static bool early_apply_microcode(u32 cpuid_1_eax, u32 old_rev, void *ucode, size_t size)
 {
 	struct cont_desc desc = { 0 };
 	struct microcode_amd *mc;
 	bool ret = false;
-	u32 rev, dummy;
 
 	desc.cpuid_1_eax = cpuid_1_eax;
 
@@ -457,22 +454,15 @@ static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size)
 	if (!mc)
 		return ret;
 
-	native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
-
 	/*
 	 * Allow application of the same revision to pick up SMT-specific
 	 * changes even if the revision of the other SMT thread is already
 	 * up-to-date.
 	 */
-	if (rev > mc->hdr.patch_id)
+	if (old_rev > mc->hdr.patch_id)
 		return ret;
 
-	if (!__apply_microcode_amd(mc)) {
-		ucode_new_rev = mc->hdr.patch_id;
-		ret = true;
-	}
-
-	return ret;
+	return !__apply_microcode_amd(mc);
 }
 
 static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
@@ -506,9 +496,12 @@ static void __init find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpi
 	*ret = cp;
 }
 
-void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
+void __init load_ucode_amd_bsp(struct early_load_data *ed, unsigned int cpuid_1_eax)
 {
 	struct cpio_data cp = { };
+	u32 dummy;
+
+	native_rdmsr(MSR_AMD64_PATCH_LEVEL, ed->old_rev, dummy);
 
 	/* Needed in load_microcode_amd() */
 	ucode_cpu_info[0].cpu_sig.sig = cpuid_1_eax;
@@ -517,7 +510,8 @@ void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
 	if (!(cp.data && cp.size))
 		return;
 
-	early_apply_microcode(cpuid_1_eax, cp.data, cp.size);
+	if (early_apply_microcode(cpuid_1_eax, ed->old_rev, cp.data, cp.size))
+		native_rdmsr(MSR_AMD64_PATCH_LEVEL, ed->new_rev, dummy);
 }
 
 static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size);
@@ -625,10 +619,8 @@ void reload_ucode_amd(unsigned int cpu)
 	rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
 
 	if (rev < mc->hdr.patch_id) {
-		if (!__apply_microcode_amd(mc)) {
-			ucode_new_rev = mc->hdr.patch_id;
-			pr_info("reload patch_level=0x%08x\n", ucode_new_rev);
-		}
+		if (!__apply_microcode_amd(mc))
+			pr_info_once("reload revision: 0x%08x\n", mc->hdr.patch_id);
 	}
 }
 
@@ -649,8 +641,6 @@ static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 	if (p && (p->patch_id == csig->rev))
 		uci->mc = p->data;
 
-	pr_info("CPU%d: patch_level=0x%08x\n", cpu, csig->rev);
-
 	return 0;
 }
 
@@ -691,8 +681,6 @@ static enum ucode_state apply_microcode_amd(int cpu)
 	rev = mc_amd->hdr.patch_id;
 	ret = UCODE_UPDATED;
 
-	pr_info("CPU%d: new patch_level=0x%08x\n", cpu, rev);
-
 out:
 	uci->cpu_sig.rev = rev;
 	c->microcode	 = rev;
@@ -935,11 +923,6 @@ struct microcode_ops * __init init_amd_microcode(void)
 		pr_warn("AMD CPU family 0x%x not supported\n", c->x86);
 		return NULL;
 	}
-
-	if (ucode_new_rev)
-		pr_info_once("microcode updated early to new patch_level=0x%08x\n",
-			     ucode_new_rev);
-
 	return &microcode_amd_ops;
 }