x86/microcode/AMD: Rip out static buffers

Load straight from the containers (initrd or builtin, for example).
There's no need to cache the patch per node.

This even simplifies the code a bit with the opportunity for more
cleanups later.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: John Allen <john.allen@amd.com>
Link: https://lore.kernel.org/r/20230720202813.3269888-1-john.allen@amd.com

Author: bp3tk0v

arch/x86/include/asm/microcode_amd.h

@@ -44,13 +44,11 @@ struct microcode_amd {
 #define PATCH_MAX_SIZE (3 * PAGE_SIZE)
 
 #ifdef CONFIG_MICROCODE_AMD
-extern void __init load_ucode_amd_bsp(unsigned int family);
-extern void load_ucode_amd_ap(unsigned int family);
+extern void load_ucode_amd_early(unsigned int cpuid_1_eax);
 extern int __init save_microcode_in_initrd_amd(unsigned int family);
 void reload_ucode_amd(unsigned int cpu);
 #else
-static inline void __init load_ucode_amd_bsp(unsigned int family) {}
-static inline void load_ucode_amd_ap(unsigned int family) {}
+static inline void load_ucode_amd_early(unsigned int cpuid_1_eax) {}
 static inline int __init
 save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
 static inline void reload_ucode_amd(unsigned int cpu) {}

arch/x86/kernel/cpu/microcode/amd.c

@@ -56,9 +56,6 @@ struct cont_desc {
 
 static u32 ucode_new_rev;
 
-/* One blob per node. */
-static u8 amd_ucode_patch[MAX_NUMNODES][PATCH_MAX_SIZE];
-
 /*
  * Microcode patch container file is prepended to the initrd in cpio
  * format. See Documentation/arch/x86/microcode.rst
@@ -415,20 +412,17 @@ 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, bool save_patch)
+static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size)
 {
 	struct cont_desc desc = { 0 };
-	u8 (*patch)[PATCH_MAX_SIZE];
 	struct microcode_amd *mc;
 	u32 rev, dummy, *new_rev;
 	bool ret = false;
 
 #ifdef CONFIG_X86_32
 	new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
-	patch	= (u8 (*)[PATCH_MAX_SIZE])__pa_nodebug(&amd_ucode_patch);
 #else
 	new_rev = &ucode_new_rev;
-	patch	= &amd_ucode_patch[0];
 #endif
 
 	desc.cpuid_1_eax = cpuid_1_eax;
@@ -452,9 +446,6 @@ static bool early_apply_microcode(u32 cpuid_1_eax, void *ucode, size_t size, boo
 	if (!__apply_microcode_amd(mc)) {
 		*new_rev = mc->hdr.patch_id;
 		ret      = true;
-
-		if (save_patch)
-			memcpy(patch, mc, min_t(u32, desc.psize, PATCH_MAX_SIZE));
 	}
 
 	return ret;
@@ -507,50 +498,20 @@ static void find_blobs_in_containers(unsigned int cpuid_1_eax, struct cpio_data
 	*ret = cp;
 }
 
-void __init load_ucode_amd_bsp(unsigned int cpuid_1_eax)
+static void apply_ucode_from_containers(unsigned int cpuid_1_eax)
 {
 	struct cpio_data cp = { };
 
 	find_blobs_in_containers(cpuid_1_eax, &cp);
 	if (!(cp.data && cp.size))
 		return;
 
-	early_apply_microcode(cpuid_1_eax, cp.data, cp.size, true);
+	early_apply_microcode(cpuid_1_eax, cp.data, cp.size);
 }
 
-void load_ucode_amd_ap(unsigned int cpuid_1_eax)
+void load_ucode_amd_early(unsigned int cpuid_1_eax)
 {
-	struct microcode_amd *mc;
-	struct cpio_data cp;
-	u32 *new_rev, rev, dummy;
-
-	if (IS_ENABLED(CONFIG_X86_32)) {
-		mc	= (struct microcode_amd *)__pa_nodebug(amd_ucode_patch);
-		new_rev = (u32 *)__pa_nodebug(&ucode_new_rev);
-	} else {
-		mc	= (struct microcode_amd *)amd_ucode_patch;
-		new_rev = &ucode_new_rev;
-	}
-
-	native_rdmsr(MSR_AMD64_PATCH_LEVEL, rev, dummy);
-
-	/*
-	 * Check whether a new patch has been saved already. Also, allow application of
-	 * the same revision in order to pick up SMT-thread-specific configuration even
-	 * if the sibling SMT thread already has an up-to-date revision.
-	 */
-	if (*new_rev && rev <= mc->hdr.patch_id) {
-		if (!__apply_microcode_amd(mc)) {
-			*new_rev = mc->hdr.patch_id;
-			return;
-		}
-	}
-
-	find_blobs_in_containers(cpuid_1_eax, &cp);
-	if (!(cp.data && cp.size))
-		return;
-
-	early_apply_microcode(cpuid_1_eax, cp.data, cp.size, false);
+	return apply_ucode_from_containers(cpuid_1_eax);
 }
 
 static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t size);
@@ -578,23 +539,6 @@ int __init save_microcode_in_initrd_amd(unsigned int cpuid_1_eax)
 	return 0;
 }
 
-void reload_ucode_amd(unsigned int cpu)
-{
-	u32 rev, dummy __always_unused;
-	struct microcode_amd *mc;
-
-	mc = (struct microcode_amd *)amd_ucode_patch[cpu_to_node(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);
-		}
-	}
-}
-
 /*
  * a small, trivial cache of per-family ucode patches
  */
@@ -655,6 +599,28 @@ static struct ucode_patch *find_patch(unsigned int cpu)
 	return cache_find_patch(equiv_id);
 }
 
+void reload_ucode_amd(unsigned int cpu)
+{
+	u32 rev, dummy __always_unused;
+	struct microcode_amd *mc;
+	struct ucode_patch *p;
+
+	p = find_patch(cpu);
+	if (!p)
+		return;
+
+	mc = p->data;
+
+	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);
+		}
+	}
+}
+
 static int collect_cpu_info_amd(int cpu, struct cpu_signature *csig)
 {
 	struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -875,9 +841,6 @@ static enum ucode_state load_microcode_amd(u8 family, const u8 *data, size_t siz
 			continue;
 
 		ret = UCODE_NEW;
-
-		memset(&amd_ucode_patch[nid], 0, PATCH_MAX_SIZE);
-		memcpy(&amd_ucode_patch[nid], p->data, min_t(u32, p->size, PATCH_MAX_SIZE));
 	}
 
 	return ret;

arch/x86/kernel/cpu/microcode/core.c

@@ -172,7 +172,7 @@ void __init load_ucode_bsp(void)
 	if (intel)
 		load_ucode_intel_bsp();
 	else
-		load_ucode_amd_bsp(cpuid_1_eax);
+		load_ucode_amd_early(cpuid_1_eax);
 }
 
 static bool check_loader_disabled_ap(void)
@@ -200,7 +200,7 @@ void load_ucode_ap(void)
 		break;
 	case X86_VENDOR_AMD:
 		if (x86_family(cpuid_1_eax) >= 0x10)
-			load_ucode_amd_ap(cpuid_1_eax);
+			load_ucode_amd_early(cpuid_1_eax);
 		break;
 	default:
 		break;