1 files changed, 222 insertions, 461 deletions

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 94dd6af9c9..334972c097 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -14,7 +14,6 @@
 #include <linux/earlycpio.h>
 #include <linux/firmware.h>
 #include <linux/uaccess.h>
-#include <linux/vmalloc.h>
 #include <linux/initrd.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -32,11 +31,14 @@
 
 static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
 
+#define UCODE_BSP_LOADED	((struct microcode_intel *)0x1UL)
+
 /* Current microcode patch used in early patching on the APs. */
-static struct microcode_intel *intel_ucode_patch;
+static struct microcode_intel *ucode_patch_va __read_mostly;
+static struct microcode_intel *ucode_patch_late __read_mostly;
 
 /* last level cache size per core */
-static int llc_size_per_core;
+static unsigned int llc_size_per_core __ro_after_init;
 
 /* microcode format is extended from prescott processors */
 struct extended_signature {
@@ -66,60 +68,52 @@ static inline unsigned int exttable_size(struct extended_sigtable *et)
 	return et->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE;
 }
 
-int intel_cpu_collect_info(struct ucode_cpu_info *uci)
+void intel_collect_cpu_info(struct cpu_signature *sig)
 {
-	unsigned int val[2];
-	unsigned int family, model;
-	struct cpu_signature csig = { 0 };
-	unsigned int eax, ebx, ecx, edx;
-
-	memset(uci, 0, sizeof(*uci));
-
-	eax = 0x00000001;
-	ecx = 0;
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-	csig.sig = eax;
+	sig->sig = cpuid_eax(1);
+	sig->pf = 0;
+	sig->rev = intel_get_microcode_revision();
 
-	family = x86_family(eax);
-	model  = x86_model(eax);
+	if (x86_model(sig->sig) >= 5 || x86_family(sig->sig) > 6) {
+		unsigned int val[2];
 
-	if (model >= 5 || family > 6) {
 		/* get processor flags from MSR 0x17 */
 		native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
-		csig.pf = 1 << ((val[1] >> 18) & 7);
+		sig->pf = 1 << ((val[1] >> 18) & 7);
 	}
+}
+EXPORT_SYMBOL_GPL(intel_collect_cpu_info);
 
-	csig.rev = intel_get_microcode_revision();
-
-	uci->cpu_sig = csig;
+static inline bool cpu_signatures_match(struct cpu_signature *s1, unsigned int sig2,
+					unsigned int pf2)
+{
+	if (s1->sig != sig2)
+		return false;
 
-	return 0;
+	/* Processor flags are either both 0 or they intersect. */
+	return ((!s1->pf && !pf2) || (s1->pf & pf2));
 }
-EXPORT_SYMBOL_GPL(intel_cpu_collect_info);
 
-/*
- * Returns 1 if update has been found, 0 otherwise.
- */
-int intel_find_matching_signature(void *mc, unsigned int csig, int cpf)
+bool intel_find_matching_signature(void *mc, struct cpu_signature *sig)
 {
 	struct microcode_header_intel *mc_hdr = mc;
-	struct extended_sigtable *ext_hdr;
 	struct extended_signature *ext_sig;
+	struct extended_sigtable *ext_hdr;
 	int i;
 
-	if (intel_cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
-		return 1;
+	if (cpu_signatures_match(sig, mc_hdr->sig, mc_hdr->pf))
+		return true;
 
 	/* Look for ext. headers: */
 	if (get_totalsize(mc_hdr) <= intel_microcode_get_datasize(mc_hdr) + MC_HEADER_SIZE)
-		return 0;
+		return false;
 
 	ext_hdr = mc + intel_microcode_get_datasize(mc_hdr) + MC_HEADER_SIZE;
 	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
 
 	for (i = 0; i < ext_hdr->count; i++) {
-		if (intel_cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
-			return 1;
+		if (cpu_signatures_match(sig, ext_sig->sig, ext_sig->pf))
+			return true;
 		ext_sig++;
 	}
 	return 0;
@@ -240,264 +234,91 @@ int intel_microcode_sanity_check(void *mc, bool print_err, int hdr_type)
 }
 EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
 
-/*
- * Returns 1 if update has been found, 0 otherwise.
- */
-static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev)
-{
-	struct microcode_header_intel *mc_hdr = mc;
-
-	if (mc_hdr->rev <= new_rev)
-		return 0;
-
-	return intel_find_matching_signature(mc, csig, cpf);
-}
-
-static struct ucode_patch *memdup_patch(void *data, unsigned int size)
-{
-	struct ucode_patch *p;
-
-	p = kzalloc(sizeof(struct ucode_patch), GFP_KERNEL);
-	if (!p)
-		return NULL;
-
-	p->data = kmemdup(data, size, GFP_KERNEL);
-	if (!p->data) {
-		kfree(p);
-		return NULL;
-	}
-
-	return p;
-}
-
-static void save_microcode_patch(struct ucode_cpu_info *uci, void *data, unsigned int size)
+static void update_ucode_pointer(struct microcode_intel *mc)
 {
-	struct microcode_header_intel *mc_hdr, *mc_saved_hdr;
-	struct ucode_patch *iter, *tmp, *p = NULL;
-	bool prev_found = false;
-	unsigned int sig, pf;
-
-	mc_hdr = (struct microcode_header_intel *)data;
-
-	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
-		mc_saved_hdr = (struct microcode_header_intel *)iter->data;
-		sig	     = mc_saved_hdr->sig;
-		pf	     = mc_saved_hdr->pf;
-
-		if (intel_find_matching_signature(data, sig, pf)) {
-			prev_found = true;
-
-			if (mc_hdr->rev <= mc_saved_hdr->rev)
-				continue;
-
-			p = memdup_patch(data, size);
-			if (!p)
-				pr_err("Error allocating buffer %p\n", data);
-			else {
-				list_replace(&iter->plist, &p->plist);
-				kfree(iter->data);
-				kfree(iter);
-			}
-		}
-	}
+	kvfree(ucode_patch_va);
 
 	/*
-	 * There weren't any previous patches found in the list cache; save the
-	 * newly found.
+	 * Save the virtual address for early loading and for eventual free
+	 * on late loading.
 	 */
-	if (!prev_found) {
-		p = memdup_patch(data, size);
-		if (!p)
-			pr_err("Error allocating buffer for %p\n", data);
-		else
-			list_add_tail(&p->plist, &microcode_cache);
-	}
-
-	if (!p)
-		return;
+	ucode_patch_va = mc;
+}
 
-	if (!intel_find_matching_signature(p->data, uci->cpu_sig.sig, uci->cpu_sig.pf))
-		return;
+static void save_microcode_patch(struct microcode_intel *patch)
+{
+	unsigned int size = get_totalsize(&patch->hdr);
+	struct microcode_intel *mc;
 
-	/*
-	 * Save for early loading. On 32-bit, that needs to be a physical
-	 * address as the APs are running from physical addresses, before
-	 * paging has been enabled.
-	 */
-	if (IS_ENABLED(CONFIG_X86_32))
-		intel_ucode_patch = (struct microcode_intel *)__pa_nodebug(p->data);
+	mc = kvmemdup(patch, size, GFP_KERNEL);
+	if (mc)
+		update_ucode_pointer(mc);
 	else
-		intel_ucode_patch = p->data;
+		pr_err("Unable to allocate microcode memory size: %u\n", size);
 }
 
-/*
- * Get microcode matching with BSP's model. Only CPUs with the same model as
- * BSP can stay in the platform.
- */
-static struct microcode_intel *
-scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
+/* Scan blob for microcode matching the boot CPUs family, model, stepping */
+static __init struct microcode_intel *scan_microcode(void *data, size_t size,
+						     struct ucode_cpu_info *uci,
+						     bool save)
 {
 	struct microcode_header_intel *mc_header;
 	struct microcode_intel *patch = NULL;
+	u32 cur_rev = uci->cpu_sig.rev;
 	unsigned int mc_size;
 
-	while (size) {
-		if (size < sizeof(struct microcode_header_intel))
-			break;
-
+	for (; size >= sizeof(struct microcode_header_intel); size -= mc_size, data += mc_size) {
 		mc_header = (struct microcode_header_intel *)data;
 
 		mc_size = get_totalsize(mc_header);
-		if (!mc_size ||
-		    mc_size > size ||
+		if (!mc_size || mc_size > size ||
 		    intel_microcode_sanity_check(data, false, MC_HEADER_TYPE_MICROCODE) < 0)
 			break;
 
-		size -= mc_size;
-
-		if (!intel_find_matching_signature(data, uci->cpu_sig.sig,
-						   uci->cpu_sig.pf)) {
-			data += mc_size;
+		if (!intel_find_matching_signature(data, &uci->cpu_sig))
 			continue;
-		}
 
+		/*
+		 * For saving the early microcode, find the matching revision which
+		 * was loaded on the BSP.
+		 *
+		 * On the BSP during early boot, find a newer revision than
+		 * actually loaded in the CPU.
+		 */
 		if (save) {
-			save_microcode_patch(uci, data, mc_size);
-			goto next;
-		}
-
-
-		if (!patch) {
-			if (!has_newer_microcode(data,
-						 uci->cpu_sig.sig,
-						 uci->cpu_sig.pf,
-						 uci->cpu_sig.rev))
-				goto next;
-
-		} else {
-			struct microcode_header_intel *phdr = &patch->hdr;
-
-			if (!has_newer_microcode(data,
-						 phdr->sig,
-						 phdr->pf,
-						 phdr->rev))
-				goto next;
+			if (cur_rev != mc_header->rev)
+				continue;
+		} else if (cur_rev >= mc_header->rev) {
+			continue;
 		}
 
-		/* We have a newer patch, save it. */
 		patch = data;
-
-next:
-		data += mc_size;
-	}
-
-	if (size)
-		return NULL;
-
-	return patch;
-}
-
-static bool load_builtin_intel_microcode(struct cpio_data *cp)
-{
-	unsigned int eax = 1, ebx, ecx = 0, edx;
-	struct firmware fw;
-	char name[30];
-
-	if (IS_ENABLED(CONFIG_X86_32))
-		return false;
-
-	native_cpuid(&eax, &ebx, &ecx, &edx);
-
-	sprintf(name, "intel-ucode/%02x-%02x-%02x",
-		      x86_family(eax), x86_model(eax), x86_stepping(eax));
-
-	if (firmware_request_builtin(&fw, name)) {
-		cp->size = fw.size;
-		cp->data = (void *)fw.data;
-		return true;
+		cur_rev = mc_header->rev;
 	}
 
-	return false;
+	return size ? NULL : patch;
 }
 
-static void print_ucode_info(int old_rev, int new_rev, unsigned int date)
+static enum ucode_state __apply_microcode(struct ucode_cpu_info *uci,
+					  struct microcode_intel *mc,
+					  u32 *cur_rev)
 {
-	pr_info_once("updated early: 0x%x -> 0x%x, date = %04x-%02x-%02x\n",
-		     old_rev,
-		     new_rev,
-		     date & 0xffff,
-		     date >> 24,
-		     (date >> 16) & 0xff);
-}
-
-#ifdef CONFIG_X86_32
-
-static int delay_ucode_info;
-static int current_mc_date;
-static int early_old_rev;
-
-/*
- * Print early updated ucode info after printk works. This is delayed info dump.
- */
-void show_ucode_info_early(void)
-{
-	struct ucode_cpu_info uci;
-
-	if (delay_ucode_info) {
-		intel_cpu_collect_info(&uci);
-		print_ucode_info(early_old_rev, uci.cpu_sig.rev, current_mc_date);
-		delay_ucode_info = 0;
-	}
-}
-
-/*
- * At this point, we can not call printk() yet. Delay printing microcode info in
- * show_ucode_info_early() until printk() works.
- */
-static void print_ucode(int old_rev, int new_rev, int date)
-{
-	int *delay_ucode_info_p;
-	int *current_mc_date_p;
-	int *early_old_rev_p;
-
-	delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
-	current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
-	early_old_rev_p = (int *)__pa_nodebug(&early_old_rev);
-
-	*delay_ucode_info_p = 1;
-	*current_mc_date_p = date;
-	*early_old_rev_p = old_rev;
-}
-#else
-
-static inline void print_ucode(int old_rev, int new_rev, int date)
-{
-	print_ucode_info(old_rev, new_rev, date);
-}
-#endif
-
-static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
-{
-	struct microcode_intel *mc;
-	u32 rev, old_rev;
+	u32 rev;
 
-	mc = uci->mc;
 	if (!mc)
-		return 0;
+		return UCODE_NFOUND;
 
 	/*
 	 * Save us the MSR write below - which is a particular expensive
 	 * operation - when the other hyperthread has updated the microcode
 	 * already.
 	 */
-	rev = intel_get_microcode_revision();
-	if (rev >= mc->hdr.rev) {
-		uci->cpu_sig.rev = rev;
+	*cur_rev = intel_get_microcode_revision();
+	if (*cur_rev >= mc->hdr.rev) {
+		uci->cpu_sig.rev = *cur_rev;
 		return UCODE_OK;
 	}
 
-	old_rev = rev;
-
 	/*
 	 * Writeback and invalidate caches before updating microcode to avoid
 	 * internal issues depending on what the microcode is updating.
@@ -509,247 +330,179 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 
 	rev = intel_get_microcode_revision();
 	if (rev != mc->hdr.rev)
-		return -1;
+		return UCODE_ERROR;
 
 	uci->cpu_sig.rev = rev;
+	return UCODE_UPDATED;
+}
 
-	if (early)
-		print_ucode(old_rev, uci->cpu_sig.rev, mc->hdr.date);
-	else
-		print_ucode_info(old_rev, uci->cpu_sig.rev, mc->hdr.date);
+static enum ucode_state apply_microcode_early(struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *mc = uci->mc;
+	u32 cur_rev;
 
-	return 0;
+	return __apply_microcode(uci, mc, &cur_rev);
 }
 
-int __init save_microcode_in_initrd_intel(void)
+static __init bool load_builtin_intel_microcode(struct cpio_data *cp)
 {
-	struct ucode_cpu_info uci;
-	struct cpio_data cp;
-
-	/*
-	 * initrd is going away, clear patch ptr. We will scan the microcode one
-	 * last time before jettisoning and save a patch, if found. Then we will
-	 * update that pointer too, with a stable patch address to use when
-	 * resuming the cores.
-	 */
-	intel_ucode_patch = NULL;
+	unsigned int eax = 1, ebx, ecx = 0, edx;
+	struct firmware fw;
+	char name[30];
 
-	if (!load_builtin_intel_microcode(&cp))
-		cp = find_microcode_in_initrd(ucode_path, false);
+	if (IS_ENABLED(CONFIG_X86_32))
+		return false;
 
-	if (!(cp.data && cp.size))
-		return 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
 
-	intel_cpu_collect_info(&uci);
+	sprintf(name, "intel-ucode/%02x-%02x-%02x",
+		x86_family(eax), x86_model(eax), x86_stepping(eax));
 
-	scan_microcode(cp.data, cp.size, &uci, true);
-	return 0;
+	if (firmware_request_builtin(&fw, name)) {
+		cp->size = fw.size;
+		cp->data = (void *)fw.data;
+		return true;
+	}
+	return false;
 }
 
-/*
- * @res_patch, output: a pointer to the patch we found.
- */
-static struct microcode_intel *__load_ucode_intel(struct ucode_cpu_info *uci)
+static __init struct microcode_intel *get_microcode_blob(struct ucode_cpu_info *uci, bool save)
 {
-	static const char *path;
 	struct cpio_data cp;
-	bool use_pa;
-
-	if (IS_ENABLED(CONFIG_X86_32)) {
-		path	  = (const char *)__pa_nodebug(ucode_path);
-		use_pa	  = true;
-	} else {
-		path	  = ucode_path;
-		use_pa	  = false;
-	}
 
-	/* try built-in microcode first */
+	intel_collect_cpu_info(&uci->cpu_sig);
+
 	if (!load_builtin_intel_microcode(&cp))
-		cp = find_microcode_in_initrd(path, use_pa);
+		cp = find_microcode_in_initrd(ucode_path);
 
 	if (!(cp.data && cp.size))
 		return NULL;
 
-	intel_cpu_collect_info(uci);
-
-	return scan_microcode(cp.data, cp.size, uci, false);
+	return scan_microcode(cp.data, cp.size, uci, save);
 }
 
-void __init load_ucode_intel_bsp(void)
+/*
+ * Invoked from an early init call to save the microcode blob which was
+ * selected during early boot when mm was not usable. The microcode must be
+ * saved because initrd is going away. It's an early init call so the APs
+ * just can use the pointer and do not have to scan initrd/builtin firmware
+ * again.
+ */
+static int __init save_builtin_microcode(void)
 {
-	struct microcode_intel *patch;
 	struct ucode_cpu_info uci;
 
-	patch = __load_ucode_intel(&uci);
-	if (!patch)
-		return;
+	if (xchg(&ucode_patch_va, NULL) != UCODE_BSP_LOADED)
+		return 0;
 
-	uci.mc = patch;
+	if (dis_ucode_ldr || boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+		return 0;
 
-	apply_microcode_early(&uci, true);
+	uci.mc = get_microcode_blob(&uci, true);
+	if (uci.mc)
+		save_microcode_patch(uci.mc);
+	return 0;
 }
+early_initcall(save_builtin_microcode);
 
-void load_ucode_intel_ap(void)
+/* Load microcode on BSP from initrd or builtin blobs */
+void __init load_ucode_intel_bsp(struct early_load_data *ed)
 {
-	struct microcode_intel *patch, **iup;
 	struct ucode_cpu_info uci;
 
-	if (IS_ENABLED(CONFIG_X86_32))
-		iup = (struct microcode_intel **) __pa_nodebug(&intel_ucode_patch);
-	else
-		iup = &intel_ucode_patch;
-
-	if (!*iup) {
-		patch = __load_ucode_intel(&uci);
-		if (!patch)
-			return;
+	uci.mc = get_microcode_blob(&uci, false);
+	ed->old_rev = uci.cpu_sig.rev;
 
-		*iup = patch;
+	if (uci.mc && apply_microcode_early(&uci) == UCODE_UPDATED) {
+		ucode_patch_va = UCODE_BSP_LOADED;
+		ed->new_rev = uci.cpu_sig.rev;
 	}
-
-	uci.mc = *iup;
-
-	apply_microcode_early(&uci, true);
 }
 
-static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
+void load_ucode_intel_ap(void)
 {
-	struct microcode_header_intel *phdr;
-	struct ucode_patch *iter, *tmp;
-
-	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
-
-		phdr = (struct microcode_header_intel *)iter->data;
-
-		if (phdr->rev <= uci->cpu_sig.rev)
-			continue;
-
-		if (!intel_find_matching_signature(phdr,
-						   uci->cpu_sig.sig,
-						   uci->cpu_sig.pf))
-			continue;
+	struct ucode_cpu_info uci;
 
-		return iter->data;
-	}
-	return NULL;
+	uci.mc = ucode_patch_va;
+	if (uci.mc)
+		apply_microcode_early(&uci);
 }
 
+/* Reload microcode on resume */
 void reload_ucode_intel(void)
 {
-	struct microcode_intel *p;
-	struct ucode_cpu_info uci;
+	struct ucode_cpu_info uci = { .mc = ucode_patch_va, };
 
-	intel_cpu_collect_info(&uci);
-
-	p = find_patch(&uci);
-	if (!p)
-		return;
-
-	uci.mc = p;
-
-	apply_microcode_early(&uci, false);
+	if (uci.mc)
+		apply_microcode_early(&uci);
 }
 
 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 {
-	struct cpuinfo_x86 *c = &cpu_data(cpu_num);
-	unsigned int val[2];
-
-	memset(csig, 0, sizeof(*csig));
-
-	csig->sig = cpuid_eax(0x00000001);
-
-	if ((c->x86_model >= 5) || (c->x86 > 6)) {
-		/* get processor flags from MSR 0x17 */
-		rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
-		csig->pf = 1 << ((val[1] >> 18) & 7);
-	}
-
-	csig->rev = c->microcode;
-
+	intel_collect_cpu_info(csig);
 	return 0;
 }
 
-static enum ucode_state apply_microcode_intel(int cpu)
+static enum ucode_state apply_microcode_late(int cpu)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
-	struct cpuinfo_x86 *c = &cpu_data(cpu);
-	bool bsp = c->cpu_index == boot_cpu_data.cpu_index;
-	struct microcode_intel *mc;
+	struct microcode_intel *mc = ucode_patch_late;
 	enum ucode_state ret;
-	static int prev_rev;
-	u32 rev;
+	u32 cur_rev;
 
-	/* We should bind the task to the CPU */
-	if (WARN_ON(raw_smp_processor_id() != cpu))
+	if (WARN_ON_ONCE(smp_processor_id() != cpu))
 		return UCODE_ERROR;
 
-	/* Look for a newer patch in our cache: */
-	mc = find_patch(uci);
-	if (!mc) {
-		mc = uci->mc;
-		if (!mc)
-			return UCODE_NFOUND;
-	}
+	ret = __apply_microcode(uci, mc, &cur_rev);
+	if (ret != UCODE_UPDATED && ret != UCODE_OK)
+		return ret;
 
-	/*
-	 * Save us the MSR write below - which is a particular expensive
-	 * operation - when the other hyperthread has updated the microcode
-	 * already.
-	 */
-	rev = intel_get_microcode_revision();
-	if (rev >= mc->hdr.rev) {
-		ret = UCODE_OK;
-		goto out;
+	if (!cpu && uci->cpu_sig.rev != cur_rev) {
+		pr_info("Updated to revision 0x%x, date = %04x-%02x-%02x\n",
+			uci->cpu_sig.rev, mc->hdr.date & 0xffff, mc->hdr.date >> 24,
+			(mc->hdr.date >> 16) & 0xff);
 	}
 
-	/*
-	 * Writeback and invalidate caches before updating microcode to avoid
-	 * internal issues depending on what the microcode is updating.
-	 */
-	native_wbinvd();
+	cpu_data(cpu).microcode	 = uci->cpu_sig.rev;
+	if (!cpu)
+		boot_cpu_data.microcode = uci->cpu_sig.rev;
 
-	/* write microcode via MSR 0x79 */
-	wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
+	return ret;
+}
 
-	rev = intel_get_microcode_revision();
+static bool ucode_validate_minrev(struct microcode_header_intel *mc_header)
+{
+	int cur_rev = boot_cpu_data.microcode;
 
-	if (rev != mc->hdr.rev) {
-		pr_err("CPU%d update to revision 0x%x failed\n",
-		       cpu, mc->hdr.rev);
-		return UCODE_ERROR;
+	/*
+	 * When late-loading, ensure the header declares a minimum revision
+	 * required to perform a late-load. The previously reserved field
+	 * is 0 in older microcode blobs.
+	 */
+	if (!mc_header->min_req_ver) {
+		pr_info("Unsafe microcode update: Microcode header does not specify a required min version\n");
+		return false;
 	}
 
-	if (bsp && rev != prev_rev) {
-		pr_info("updated to revision 0x%x, date = %04x-%02x-%02x\n",
-			rev,
-			mc->hdr.date & 0xffff,
-			mc->hdr.date >> 24,
-			(mc->hdr.date >> 16) & 0xff);
-		prev_rev = rev;
+	/*
+	 * Check whether the current revision is either greater or equal to
+	 * to the minimum revision specified in the header.
+	 */
+	if (cur_rev < mc_header->min_req_ver) {
+		pr_info("Unsafe microcode update: Current revision 0x%x too old\n", cur_rev);
+		pr_info("Current should be at 0x%x or higher. Use early loading instead\n", mc_header->min_req_ver);
+		return false;
 	}
-
-	ret = UCODE_UPDATED;
-
-out:
-	uci->cpu_sig.rev = rev;
-	c->microcode	 = rev;
-
-	/* Update boot_cpu_data's revision too, if we're on the BSP: */
-	if (bsp)
-		boot_cpu_data.microcode = rev;
-
-	return ret;
+	return true;
 }
 
-static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
+static enum ucode_state parse_microcode_blobs(int cpu, struct iov_iter *iter)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
-	unsigned int curr_mc_size = 0, new_mc_size = 0;
-	enum ucode_state ret = UCODE_OK;
-	int new_rev = uci->cpu_sig.rev;
+	bool is_safe, new_is_safe = false;
+	int cur_rev = uci->cpu_sig.rev;
+	unsigned int curr_mc_size = 0;
 	u8 *new_mc = NULL, *mc = NULL;
-	unsigned int csig, cpf;
 
 	while (iov_iter_count(iter)) {
 		struct microcode_header_intel mc_header;
@@ -758,68 +511,66 @@ static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
 
 		if (!copy_from_iter_full(&mc_header, sizeof(mc_header), iter)) {
 			pr_err("error! Truncated or inaccessible header in microcode data file\n");
-			break;
+			goto fail;
 		}
 
 		mc_size = get_totalsize(&mc_header);
 		if (mc_size < sizeof(mc_header)) {
 			pr_err("error! Bad data in microcode data file (totalsize too small)\n");
-			break;
+			goto fail;
 		}
 		data_size = mc_size - sizeof(mc_header);
 		if (data_size > iov_iter_count(iter)) {
 			pr_err("error! Bad data in microcode data file (truncated file?)\n");
-			break;
+			goto fail;
 		}
 
 		/* For performance reasons, reuse mc area when possible */
 		if (!mc || mc_size > curr_mc_size) {
-			vfree(mc);
-			mc = vmalloc(mc_size);
+			kvfree(mc);
+			mc = kvmalloc(mc_size, GFP_KERNEL);
 			if (!mc)
-				break;
+				goto fail;
 			curr_mc_size = mc_size;
 		}
 
 		memcpy(mc, &mc_header, sizeof(mc_header));
 		data = mc + sizeof(mc_header);
 		if (!copy_from_iter_full(data, data_size, iter) ||
-		    intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0) {
-			break;
-		}
+		    intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0)
+			goto fail;
 
-		csig = uci->cpu_sig.sig;
-		cpf = uci->cpu_sig.pf;
-		if (has_newer_microcode(mc, csig, cpf, new_rev)) {
-			vfree(new_mc);
-			new_rev = mc_header.rev;
-			new_mc  = mc;
-			new_mc_size = mc_size;
-			mc = NULL;	/* trigger new vmalloc */
-			ret = UCODE_NEW;
-		}
-	}
+		if (cur_rev >= mc_header.rev)
+			continue;
 
-	vfree(mc);
+		if (!intel_find_matching_signature(mc, &uci->cpu_sig))
+			continue;
 
-	if (iov_iter_count(iter)) {
-		vfree(new_mc);
-		return UCODE_ERROR;
+		is_safe = ucode_validate_minrev(&mc_header);
+		if (force_minrev && !is_safe)
+			continue;
+
+		kvfree(new_mc);
+		cur_rev = mc_header.rev;
+		new_mc  = mc;
+		new_is_safe = is_safe;
+		mc = NULL;
 	}
 
+	if (iov_iter_count(iter))
+		goto fail;
+
+	kvfree(mc);
 	if (!new_mc)
 		return UCODE_NFOUND;
 
-	vfree(uci->mc);
-	uci->mc = (struct microcode_intel *)new_mc;
-
-	/* Save for CPU hotplug */
-	save_microcode_patch(uci, new_mc, new_mc_size);
+	ucode_patch_late = (struct microcode_intel *)new_mc;
+	return new_is_safe ? UCODE_NEW_SAFE : UCODE_NEW;
 
-	pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
-		 cpu, new_rev, uci->cpu_sig.rev);
-
-	return ret;
+fail:
+	kvfree(mc);
+	kvfree(new_mc);
+	return UCODE_ERROR;
 }
 
 static bool is_blacklisted(unsigned int cpu)
@@ -868,26 +619,36 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device)
 	kvec.iov_base = (void *)firmware->data;
 	kvec.iov_len = firmware->size;
 	iov_iter_kvec(&iter, ITER_SOURCE, &kvec, 1, firmware->size);
-	ret = generic_load_microcode(cpu, &iter);
+	ret = parse_microcode_blobs(cpu, &iter);
 
 	release_firmware(firmware);
 
 	return ret;
 }
 
+static void finalize_late_load(int result)
+{
+	if (!result)
+		update_ucode_pointer(ucode_patch_late);
+	else
+		kvfree(ucode_patch_late);
+	ucode_patch_late = NULL;
+}
+
 static struct microcode_ops microcode_intel_ops = {
-	.request_microcode_fw             = request_microcode_fw,
-	.collect_cpu_info                 = collect_cpu_info,
-	.apply_microcode                  = apply_microcode_intel,
+	.request_microcode_fw	= request_microcode_fw,
+	.collect_cpu_info	= collect_cpu_info,
+	.apply_microcode	= apply_microcode_late,
+	.finalize_late_load	= finalize_late_load,
+	.use_nmi		= IS_ENABLED(CONFIG_X86_64),
 };
 
-static int __init calc_llc_size_per_core(struct cpuinfo_x86 *c)
+static __init void calc_llc_size_per_core(struct cpuinfo_x86 *c)
 {
 	u64 llc_size = c->x86_cache_size * 1024ULL;
 
 	do_div(llc_size, c->x86_max_cores);
-
-	return (int)llc_size;
+	llc_size_per_core = (unsigned int)llc_size;
 }
 
 struct microcode_ops * __init init_intel_microcode(void)
@@ -900,7 +661,7 @@ struct microcode_ops * __init init_intel_microcode(void)
 		return NULL;
 	}
 
-	llc_size_per_core = calc_llc_size_per_core(c);
+	calc_llc_size_per_core(c);
 
 	return &microcode_intel_ops;
 }