Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 microcode update from Ingo Molnar:
 "The biggest change (by Borislav Petkov) is a thorough rewrite of the
  Intel microcode loader and its interactions with the core code.

  The biggest conceptual change is the decoupling of the microcode
  loading on boot and application processors (which load the microcode
  in different scenarios), so that both parse the input patches with as
  few assumptions as possible - this also fixes various kernel address
  space randomization bugs. (The AP side then goes on and caches the
  result to improve boot performance.)

  Since the AMD side already did this, this change also opened up the
  path towards more unification/simplification of the core microcode
  loading infrastructure:

     10 files changed, 647 insertions(+), 940 deletions(-)

  which speaks for itself"

* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode: Bump driver version, update copyrights
  x86/microcode: Rework microcode loading
  x86/microcode/intel: Remove intel_lib.c
  x86/microcode/amd: Move private inlines to .c and mark local functions static
  x86/microcode: Collect CPU info on resume
  x86/microcode: Issue the debug printk on resume only on success
  x86/microcode/amd: Hand down the CPU family
  x86/microcode: Export the microcode cache linked list
  x86/microcode: Remove one #ifdef clause
  x86/microcode/intel: Simplify generic_load_microcode()
  x86/microcode: Move driver authors to CREDITS
  x86/microcode: Run the AP-loading routine only on the application processors

1 files changed, 349 insertions, 485 deletions

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index cdc0deab00c9..54d50c3694d8 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -39,125 +39,83 @@
 #include <asm/setup.h>
 #include <asm/msr.h>
 
-/*
- * Temporary microcode blobs pointers storage. We note here during early load
- * the pointers to microcode blobs we've got from whatever storage (detached
- * initrd, builtin). Later on, we put those into final storage
- * mc_saved_data.mc_saved.
- *
- * Important: those are offsets from the beginning of initrd or absolute
- * addresses within the kernel image when built-in.
- */
-static unsigned long mc_tmp_ptrs[MAX_UCODE_COUNT];
-
-static struct mc_saved_data {
-	unsigned int num_saved;
-	struct microcode_intel **mc_saved;
-} mc_saved_data;
+static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
 
-/* Microcode blobs within the initrd. 0 if builtin. */
-static struct ucode_blobs {
-	unsigned long start;
-	bool valid;
-} blobs;
+/* Current microcode patch used in early patching */
+struct microcode_intel *intel_ucode_patch;
 
-/* Go through saved patches and find the one suitable for the current CPU. */
-static enum ucode_state
-find_microcode_patch(struct microcode_intel **saved,
-		     unsigned int num_saved, struct ucode_cpu_info *uci)
+static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
+					unsigned int s2, unsigned int p2)
 {
-	struct microcode_intel *ucode_ptr, *new_mc = NULL;
-	struct microcode_header_intel *mc_hdr;
-	int new_rev, ret, i;
-
-	new_rev = uci->cpu_sig.rev;
-
-	for (i = 0; i < num_saved; i++) {
-		ucode_ptr = saved[i];
-		mc_hdr	  = (struct microcode_header_intel *)ucode_ptr;
-
-		ret = has_newer_microcode(ucode_ptr,
-					  uci->cpu_sig.sig,
-					  uci->cpu_sig.pf,
-					  new_rev);
-		if (!ret)
-			continue;
-
-		new_rev = mc_hdr->rev;
-		new_mc  = ucode_ptr;
-	}
+	if (s1 != s2)
+		return false;
 
-	if (!new_mc)
-		return UCODE_NFOUND;
+	/* Processor flags are either both 0 ... */
+	if (!p1 && !p2)
+		return true;
 
-	uci->mc = (struct microcode_intel *)new_mc;
-	return UCODE_OK;
+	/* ... or they intersect. */
+	return p1 & p2;
 }
 
-static inline void
-copy_ptrs(struct microcode_intel **mc_saved, unsigned long *mc_ptrs,
-	  unsigned long off, int num_saved)
+/*
+ * Returns 1 if update has been found, 0 otherwise.
+ */
+static int find_matching_signature(void *mc, unsigned int csig, int cpf)
 {
+	struct microcode_header_intel *mc_hdr = mc;
+	struct extended_sigtable *ext_hdr;
+	struct extended_signature *ext_sig;
 	int i;
 
-	for (i = 0; i < num_saved; i++)
-		mc_saved[i] = (struct microcode_intel *)(mc_ptrs[i] + off);
-}
-
-#ifdef CONFIG_X86_32
-static void
-microcode_phys(struct microcode_intel **mc_saved_tmp, struct mc_saved_data *mcs)
-{
-	int i;
-	struct microcode_intel ***mc_saved;
+	if (cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
+		return 1;
 
-	mc_saved = (struct microcode_intel ***)__pa_nodebug(&mcs->mc_saved);
+	/* Look for ext. headers: */
+	if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
+		return 0;
 
-	for (i = 0; i < mcs->num_saved; i++) {
-		struct microcode_intel *p;
+	ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
+	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
 
-		p = *(struct microcode_intel **)__pa_nodebug(mcs->mc_saved + i);
-		mc_saved_tmp[i] = (struct microcode_intel *)__pa_nodebug(p);
+	for (i = 0; i < ext_hdr->count; i++) {
+		if (cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
+			return 1;
+		ext_sig++;
 	}
+	return 0;
 }
-#endif
 
-static enum ucode_state
-load_microcode(struct mc_saved_data *mcs, unsigned long *mc_ptrs,
-	       unsigned long offset, struct ucode_cpu_info *uci)
+/*
+ * 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_intel *mc_saved_tmp[MAX_UCODE_COUNT];
-	unsigned int count = mcs->num_saved;
+	struct microcode_header_intel *mc_hdr = mc;
 
-	if (!mcs->mc_saved) {
-		copy_ptrs(mc_saved_tmp, mc_ptrs, offset, count);
+	if (mc_hdr->rev <= new_rev)
+		return 0;
 
-		return find_microcode_patch(mc_saved_tmp, count, uci);
-	} else {
-#ifdef CONFIG_X86_32
-		microcode_phys(mc_saved_tmp, mcs);
-		return find_microcode_patch(mc_saved_tmp, count, uci);
-#else
-		return find_microcode_patch(mcs->mc_saved, count, uci);
-#endif
-	}
+	return find_matching_signature(mc, csig, cpf);
 }
 
 /*
  * Given CPU signature and a microcode patch, this function finds if the
  * microcode patch has matching family and model with the CPU.
+ *
+ * %true - if there's a match
+ * %false - otherwise
  */
-static enum ucode_state
-matching_model_microcode(struct microcode_header_intel *mc_header,
-			unsigned long sig)
+static bool microcode_matches(struct microcode_header_intel *mc_header,
+			      unsigned long sig)
 {
-	unsigned int fam, model;
-	unsigned int fam_ucode, model_ucode;
-	struct extended_sigtable *ext_header;
 	unsigned long total_size = get_totalsize(mc_header);
 	unsigned long data_size = get_datasize(mc_header);
-	int ext_sigcount, i;
+	struct extended_sigtable *ext_header;
+	unsigned int fam_ucode, model_ucode;
 	struct extended_signature *ext_sig;
+	unsigned int fam, model;
+	int ext_sigcount, i;
 
 	fam   = x86_family(sig);
 	model = x86_model(sig);
@@ -166,11 +124,11 @@ matching_model_microcode(struct microcode_header_intel *mc_header,
 	model_ucode = x86_model(mc_header->sig);
 
 	if (fam == fam_ucode && model == model_ucode)
-		return UCODE_OK;
+		return true;
 
 	/* Look for ext. headers: */
 	if (total_size <= data_size + MC_HEADER_SIZE)
-		return UCODE_NFOUND;
+		return false;
 
 	ext_header   = (void *) mc_header + data_size + MC_HEADER_SIZE;
 	ext_sig      = (void *)ext_header + EXT_HEADER_SIZE;
@@ -181,192 +139,242 @@ matching_model_microcode(struct microcode_header_intel *mc_header,
 		model_ucode = x86_model(ext_sig->sig);
 
 		if (fam == fam_ucode && model == model_ucode)
-			return UCODE_OK;
+			return true;
 
 		ext_sig++;
 	}
-	return UCODE_NFOUND;
+	return false;
 }
 
-static int
-save_microcode(struct mc_saved_data *mcs,
-	       struct microcode_intel **mc_saved_src,
-	       unsigned int num_saved)
+static struct ucode_patch *__alloc_microcode_buf(void *data, unsigned int size)
 {
-	int i, j;
-	struct microcode_intel **saved_ptr;
-	int ret;
+	struct ucode_patch *p;
 
-	if (!num_saved)
-		return -EINVAL;
+	p = kzalloc(size, GFP_KERNEL);
+	if (!p)
+		return ERR_PTR(-ENOMEM);
 
-	/*
-	 * Copy new microcode data.
-	 */
-	saved_ptr = kcalloc(num_saved, sizeof(struct microcode_intel *), GFP_KERNEL);
-	if (!saved_ptr)
-		return -ENOMEM;
-
-	for (i = 0; i < num_saved; i++) {
-		struct microcode_header_intel *mc_hdr;
-		struct microcode_intel *mc;
-		unsigned long size;
-
-		if (!mc_saved_src[i]) {
-			ret = -EINVAL;
-			goto err;
-		}
+	p->data = kmemdup(data, size, GFP_KERNEL);
+	if (!p->data) {
+		kfree(p);
+		return ERR_PTR(-ENOMEM);
+	}
 
-		mc     = mc_saved_src[i];
-		mc_hdr = &mc->hdr;
-		size   = get_totalsize(mc_hdr);
+	return p;
+}
 
-		saved_ptr[i] = kmemdup(mc, size, GFP_KERNEL);
-		if (!saved_ptr[i]) {
-			ret = -ENOMEM;
-			goto err;
+static void save_microcode_patch(void *data, unsigned int size)
+{
+	struct microcode_header_intel *mc_hdr, *mc_saved_hdr;
+	struct ucode_patch *iter, *tmp, *p;
+	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 (find_matching_signature(data, sig, pf)) {
+			prev_found = true;
+
+			if (mc_hdr->rev <= mc_saved_hdr->rev)
+				continue;
+
+			p = __alloc_microcode_buf(data, size);
+			if (IS_ERR(p))
+				pr_err("Error allocating buffer %p\n", data);
+			else
+				list_replace(&iter->plist, &p->plist);
 		}
 	}
 
 	/*
-	 * Point to newly saved microcode.
+	 * There weren't any previous patches found in the list cache; save the
+	 * newly found.
 	 */
-	mcs->mc_saved  = saved_ptr;
-	mcs->num_saved = num_saved;
-
-	return 0;
-
-err:
-	for (j = 0; j <= i; j++)
-		kfree(saved_ptr[j]);
-	kfree(saved_ptr);
-
-	return ret;
+	if (!prev_found) {
+		p = __alloc_microcode_buf(data, size);
+		if (IS_ERR(p))
+			pr_err("Error allocating buffer for %p\n", data);
+		else
+			list_add_tail(&p->plist, &microcode_cache);
+	}
 }
 
-/*
- * A microcode patch in ucode_ptr is saved into mc_saved
- * - if it has matching signature and newer revision compared to an existing
- *   patch mc_saved.
- * - or if it is a newly discovered microcode patch.
- *
- * The microcode patch should have matching model with CPU.
- *
- * Returns: The updated number @num_saved of saved microcode patches.
- */
-static unsigned int _save_mc(struct microcode_intel **mc_saved,
-			     u8 *ucode_ptr, unsigned int num_saved)
+static int microcode_sanity_check(void *mc, int print_err)
 {
-	struct microcode_header_intel *mc_hdr, *mc_saved_hdr;
-	unsigned int sig, pf;
-	int found = 0, i;
+	unsigned long total_size, data_size, ext_table_size;
+	struct microcode_header_intel *mc_header = mc;
+	struct extended_sigtable *ext_header = NULL;
+	u32 sum, orig_sum, ext_sigcount = 0, i;
+	struct extended_signature *ext_sig;
 
-	mc_hdr = (struct microcode_header_intel *)ucode_ptr;
+	total_size = get_totalsize(mc_header);
+	data_size = get_datasize(mc_header);
 
-	for (i = 0; i < num_saved; i++) {
-		mc_saved_hdr = (struct microcode_header_intel *)mc_saved[i];
-		sig	     = mc_saved_hdr->sig;
-		pf	     = mc_saved_hdr->pf;
+	if (data_size + MC_HEADER_SIZE > total_size) {
+		if (print_err)
+			pr_err("Error: bad microcode data file size.\n");
+		return -EINVAL;
+	}
 
-		if (!find_matching_signature(ucode_ptr, sig, pf))
-			continue;
+	if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
+		if (print_err)
+			pr_err("Error: invalid/unknown microcode update format.\n");
+		return -EINVAL;
+	}
 
-		found = 1;
+	ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
+	if (ext_table_size) {
+		u32 ext_table_sum = 0;
+		u32 *ext_tablep;
 
-		if (mc_hdr->rev <= mc_saved_hdr->rev)
-			continue;
+		if ((ext_table_size < EXT_HEADER_SIZE)
+		 || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
+			if (print_err)
+				pr_err("Error: truncated extended signature table.\n");
+			return -EINVAL;
+		}
+
+		ext_header = mc + MC_HEADER_SIZE + data_size;
+		if (ext_table_size != exttable_size(ext_header)) {
+			if (print_err)
+				pr_err("Error: extended signature table size mismatch.\n");
+			return -EFAULT;
+		}
+
+		ext_sigcount = ext_header->count;
 
 		/*
-		 * Found an older ucode saved earlier. Replace it with
-		 * this newer one.
+		 * Check extended table checksum: the sum of all dwords that
+		 * comprise a valid table must be 0.
 		 */
-		mc_saved[i] = (struct microcode_intel *)ucode_ptr;
-		break;
+		ext_tablep = (u32 *)ext_header;
+
+		i = ext_table_size / sizeof(u32);
+		while (i--)
+			ext_table_sum += ext_tablep[i];
+
+		if (ext_table_sum) {
+			if (print_err)
+				pr_warn("Bad extended signature table checksum, aborting.\n");
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * Calculate the checksum of update data and header. The checksum of
+	 * valid update data and header including the extended signature table
+	 * must be 0.
+	 */
+	orig_sum = 0;
+	i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
+	while (i--)
+		orig_sum += ((u32 *)mc)[i];
+
+	if (orig_sum) {
+		if (print_err)
+			pr_err("Bad microcode data checksum, aborting.\n");
+		return -EINVAL;
 	}
 
-	/* Newly detected microcode, save it to memory. */
-	if (i >= num_saved && !found)
-		mc_saved[num_saved++] = (struct microcode_intel *)ucode_ptr;
+	if (!ext_table_size)
+		return 0;
 
-	return num_saved;
+	/*
+	 * Check extended signature checksum: 0 => valid.
+	 */
+	for (i = 0; i < ext_sigcount; i++) {
+		ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
+			  EXT_SIGNATURE_SIZE * i;
+
+		sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
+		      (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
+		if (sum) {
+			if (print_err)
+				pr_err("Bad extended signature checksum, aborting.\n");
+			return -EINVAL;
+		}
+	}
+	return 0;
 }
 
 /*
  * Get microcode matching with BSP's model. Only CPUs with the same model as
  * BSP can stay in the platform.
  */
-static enum ucode_state __init
-get_matching_model_microcode(unsigned long start, void *data, size_t size,
-			     struct mc_saved_data *mcs, unsigned long *mc_ptrs,
-			     struct ucode_cpu_info *uci)
+static struct microcode_intel *
+scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
 {
-	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
 	struct microcode_header_intel *mc_header;
-	unsigned int num_saved = mcs->num_saved;
-	enum ucode_state state = UCODE_OK;
-	unsigned int leftover = size;
-	u8 *ucode_ptr = data;
+	struct microcode_intel *patch = NULL;
 	unsigned int mc_size;
-	int i;
-
-	while (leftover && num_saved < ARRAY_SIZE(mc_saved_tmp)) {
 
-		if (leftover < sizeof(mc_header))
+	while (size) {
+		if (size < sizeof(struct microcode_header_intel))
 			break;
 
-		mc_header = (struct microcode_header_intel *)ucode_ptr;
+		mc_header = (struct microcode_header_intel *)data;
 
 		mc_size = get_totalsize(mc_header);
-		if (!mc_size || mc_size > leftover ||
-			microcode_sanity_check(ucode_ptr, 0) < 0)
+		if (!mc_size ||
+		    mc_size > size ||
+		    microcode_sanity_check(data, 0) < 0)
 			break;
 
-		leftover -= mc_size;
+		size -= mc_size;
 
-		/*
-		 * Since APs with same family and model as the BSP may boot in
-		 * the platform, we need to find and save microcode patches
-		 * with the same family and model as the BSP.
-		 */
-		if (matching_model_microcode(mc_header, uci->cpu_sig.sig) != UCODE_OK) {
-			ucode_ptr += mc_size;
+		if (!microcode_matches(mc_header, uci->cpu_sig.sig)) {
+			data += mc_size;
 			continue;
 		}
 
-		num_saved = _save_mc(mc_saved_tmp, ucode_ptr, num_saved);
+		if (save) {
+			save_microcode_patch(data, mc_size);
+			goto next;
+		}
 
-		ucode_ptr += mc_size;
-	}
 
-	if (leftover) {
-		state = UCODE_ERROR;
-		return state;
-	}
+		if (!patch) {
+			if (!has_newer_microcode(data,
+						 uci->cpu_sig.sig,
+						 uci->cpu_sig.pf,
+						 uci->cpu_sig.rev))
+				goto next;
 
-	if (!num_saved) {
-		state = UCODE_NFOUND;
-		return state;
-	}
+		} else {
+			struct microcode_header_intel *phdr = &patch->hdr;
 
-	for (i = 0; i < num_saved; i++)
-		mc_ptrs[i] = (unsigned long)mc_saved_tmp[i] - start;
+			if (!has_newer_microcode(data,
+						 phdr->sig,
+						 phdr->pf,
+						 phdr->rev))
+				goto next;
+		}
+
+		/* We have a newer patch, save it. */
+		patch = data;
 
-	mcs->num_saved = num_saved;
+next:
+		data += mc_size;
+	}
 
-	return state;
+	if (size)
+		return NULL;
+
+	return patch;
 }
 
 static int collect_cpu_info_early(struct ucode_cpu_info *uci)
 {
 	unsigned int val[2];
 	unsigned int family, model;
-	struct cpu_signature csig;
+	struct cpu_signature csig = { 0 };
 	unsigned int eax, ebx, ecx, edx;
 
-	csig.sig = 0;
-	csig.pf = 0;
-	csig.rev = 0;
-
 	memset(uci, 0, sizeof(*uci));
 
 	eax = 0x00000001;
@@ -374,8 +382,8 @@ static int collect_cpu_info_early(struct ucode_cpu_info *uci)
 	native_cpuid(&eax, &ebx, &ecx, &edx);
 	csig.sig = eax;
 
-	family = x86_family(csig.sig);
-	model  = x86_model(csig.sig);
+	family = x86_family(eax);
+	model  = x86_model(eax);
 
 	if ((model >= 5) || (family > 6)) {
 		/* get processor flags from MSR 0x17 */
@@ -401,40 +409,41 @@ static int collect_cpu_info_early(struct ucode_cpu_info *uci)
 static void show_saved_mc(void)
 {
 #ifdef DEBUG
-	int i, j;
+	int i = 0, j;
 	unsigned int sig, pf, rev, total_size, data_size, date;
 	struct ucode_cpu_info uci;
+	struct ucode_patch *p;
 
-	if (!mc_saved_data.num_saved) {
+	if (list_empty(&microcode_cache)) {
 		pr_debug("no microcode data saved.\n");
 		return;
 	}
-	pr_debug("Total microcode saved: %d\n", mc_saved_data.num_saved);
 
 	collect_cpu_info_early(&uci);
 
-	sig = uci.cpu_sig.sig;
-	pf = uci.cpu_sig.pf;
-	rev = uci.cpu_sig.rev;
+	sig	= uci.cpu_sig.sig;
+	pf	= uci.cpu_sig.pf;
+	rev	= uci.cpu_sig.rev;
 	pr_debug("CPU: sig=0x%x, pf=0x%x, rev=0x%x\n", sig, pf, rev);
 
-	for (i = 0; i < mc_saved_data.num_saved; i++) {
+	list_for_each_entry(p, &microcode_cache, plist) {
 		struct microcode_header_intel *mc_saved_header;
 		struct extended_sigtable *ext_header;
-		int ext_sigcount;
 		struct extended_signature *ext_sig;
+		int ext_sigcount;
+
+		mc_saved_header = (struct microcode_header_intel *)p->data;
 
-		mc_saved_header = (struct microcode_header_intel *)
-				  mc_saved_data.mc_saved[i];
-		sig = mc_saved_header->sig;
-		pf = mc_saved_header->pf;
-		rev = mc_saved_header->rev;
-		total_size = get_totalsize(mc_saved_header);
-		data_size = get_datasize(mc_saved_header);
-		date = mc_saved_header->date;
+		sig	= mc_saved_header->sig;
+		pf	= mc_saved_header->pf;
+		rev	= mc_saved_header->rev;
+		date	= mc_saved_header->date;
+
+		total_size	= get_totalsize(mc_saved_header);
+		data_size	= get_datasize(mc_saved_header);
 
 		pr_debug("mc_saved[%d]: sig=0x%x, pf=0x%x, rev=0x%x, total size=0x%x, date = %04x-%02x-%02x\n",
-			 i, sig, pf, rev, total_size,
+			 i++, sig, pf, rev, total_size,
 			 date & 0xffff,
 			 date >> 24,
 			 (date >> 16) & 0xff);
@@ -443,7 +452,7 @@ static void show_saved_mc(void)
 		if (total_size <= data_size + MC_HEADER_SIZE)
 			continue;
 
-		ext_header = (void *) mc_saved_header + data_size + MC_HEADER_SIZE;
+		ext_header = (void *)mc_saved_header + data_size + MC_HEADER_SIZE;
 		ext_sigcount = ext_header->count;
 		ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
 
@@ -456,85 +465,43 @@ static void show_saved_mc(void)
 
 			ext_sig++;
 		}
-
 	}
 #endif
 }
 
 /*
- * Save this mc into mc_saved_data. So it will be loaded early when a CPU is
- * hot added or resumes.
- *
- * Please make sure this mc should be a valid microcode patch before calling
- * this function.
+ * Save this microcode patch. It will be loaded early when a CPU is
+ * hot-added or resumes.
  */
-static void save_mc_for_early(u8 *mc)
+static void save_mc_for_early(u8 *mc, unsigned int size)
 {
 #ifdef CONFIG_HOTPLUG_CPU
 	/* Synchronization during CPU hotplug. */
 	static DEFINE_MUTEX(x86_cpu_microcode_mutex);
 
-	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
-	unsigned int mc_saved_count_init;
-	unsigned int num_saved;
-	struct microcode_intel **mc_saved;
-	int ret, i;
-
 	mutex_lock(&x86_cpu_microcode_mutex);
 
-	mc_saved_count_init = mc_saved_data.num_saved;
-	num_saved = mc_saved_data.num_saved;
-	mc_saved = mc_saved_data.mc_saved;
-
-	if (mc_saved && num_saved)
-		memcpy(mc_saved_tmp, mc_saved,
-		       num_saved * sizeof(struct microcode_intel *));
-	/*
-	 * Save the microcode patch mc in mc_save_tmp structure if it's a newer
-	 * version.
-	 */
-	num_saved = _save_mc(mc_saved_tmp, mc, num_saved);
-
-	/*
-	 * Save the mc_save_tmp in global mc_saved_data.
-	 */
-	ret = save_microcode(&mc_saved_data, mc_saved_tmp, num_saved);
-	if (ret) {
-		pr_err("Cannot save microcode patch.\n");
-		goto out;
-	}
-
+	save_microcode_patch(mc, size);
 	show_saved_mc();
 
-	/*
-	 * Free old saved microcode data.
-	 */
-	if (mc_saved) {
-		for (i = 0; i < mc_saved_count_init; i++)
-			kfree(mc_saved[i]);
-		kfree(mc_saved);
-	}
-
-out:
 	mutex_unlock(&x86_cpu_microcode_mutex);
 #endif
 }
 
-static bool __init load_builtin_intel_microcode(struct cpio_data *cp)
+static bool load_builtin_intel_microcode(struct cpio_data *cp)
 {
-#ifdef CONFIG_X86_64
-	unsigned int eax = 0x00000001, ebx, ecx = 0, edx;
+	unsigned int eax = 1, ebx, ecx = 0, edx;
 	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));
 
 	return get_builtin_firmware(cp, name);
-#else
-	return false;
-#endif
 }
 
 /*
@@ -570,8 +537,7 @@ void show_ucode_info_early(void)
 }
 
 /*
- * At this point, we can not call printk() yet. Keep microcode patch number in
- * mc_saved_data.mc_saved and delay printing microcode info in
+ * 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(struct ucode_cpu_info *uci)
@@ -648,206 +614,140 @@ static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 	return 0;
 }
 
-/*
- * This function converts microcode patch offsets previously stored in
- * mc_tmp_ptrs to pointers and stores the pointers in mc_saved_data.
- */
 int __init save_microcode_in_initrd_intel(void)
 {
-	struct microcode_intel *mc_saved[MAX_UCODE_COUNT];
-	unsigned int count = mc_saved_data.num_saved;
-	unsigned long offset = 0;
-	int ret;
-
-	if (!count)
-		return 0;
+	struct ucode_cpu_info uci;
+	struct cpio_data cp;
 
 	/*
-	 * We have found a valid initrd but it might've been relocated in the
-	 * meantime so get its updated address.
+	 * AP loading didn't find any microcode patch, no need to save anything.
 	 */
-	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && blobs.valid)
-		offset = initrd_start;
-
-	copy_ptrs(mc_saved, mc_tmp_ptrs, offset, count);
+	if (!intel_ucode_patch || IS_ERR(intel_ucode_patch))
+		return 0;
 
-	ret = save_microcode(&mc_saved_data, mc_saved, count);
-	if (ret)
-		pr_err("Cannot save microcode patches from initrd.\n");
-	else
-		show_saved_mc();
+	if (!load_builtin_intel_microcode(&cp))
+		cp = find_microcode_in_initrd(ucode_path, false);
 
-	return ret;
-}
+	if (!(cp.data && cp.size))
+		return 0;
 
-static __init enum ucode_state
-__scan_microcode_initrd(struct cpio_data *cd, struct ucode_blobs *blbp)
-{
-#ifdef CONFIG_BLK_DEV_INITRD
-	static __initdata char ucode_name[] = "kernel/x86/microcode/GenuineIntel.bin";
-	char *p = IS_ENABLED(CONFIG_X86_32) ? (char *)__pa_nodebug(ucode_name)
-						    : ucode_name;
-# ifdef CONFIG_X86_32
-	unsigned long start = 0, size;
-	struct boot_params *params;
+	collect_cpu_info_early(&uci);
 
-	params = (struct boot_params *)__pa_nodebug(&boot_params);
-	size   = params->hdr.ramdisk_size;
+	scan_microcode(cp.data, cp.size, &uci, true);
 
-	/*
-	 * Set start only if we have an initrd image. We cannot use initrd_start
-	 * because it is not set that early yet.
-	 */
-	start = (size ? params->hdr.ramdisk_image : 0);
+	show_saved_mc();
 
-# else /* CONFIG_X86_64 */
-	unsigned long start = 0, size;
+	return 0;
+}
 
-	size  = (u64)boot_params.ext_ramdisk_size << 32;
-	size |= boot_params.hdr.ramdisk_size;
 
-	if (size) {
-		start  = (u64)boot_params.ext_ramdisk_image << 32;
-		start |= boot_params.hdr.ramdisk_image;
+/*
+ * @res_patch, output: a pointer to the patch we found.
+ */
+static struct microcode_intel *__load_ucode_intel(struct ucode_cpu_info *uci)
+{
+	static const char *path;
+	struct cpio_data cp;
+	bool use_pa;
 
-		start += PAGE_OFFSET;
+	if (IS_ENABLED(CONFIG_X86_32)) {
+		path	  = (const char *)__pa_nodebug(ucode_path);
+		use_pa	  = true;
+	} else {
+		path	  = ucode_path;
+		use_pa	  = false;
 	}
-# endif
-
-	*cd = find_cpio_data(p, (void *)start, size, NULL);
-	if (cd->data) {
-		blbp->start = start;
-		blbp->valid = true;
 
-		return UCODE_OK;
-	} else
-#endif /* CONFIG_BLK_DEV_INITRD */
-		return UCODE_ERROR;
-}
+	/* try built-in microcode first */
+	if (!load_builtin_intel_microcode(&cp))
+		cp = find_microcode_in_initrd(path, use_pa);
 
-static __init enum ucode_state
-scan_microcode(struct mc_saved_data *mcs, unsigned long *mc_ptrs,
-	       struct ucode_cpu_info *uci, struct ucode_blobs *blbp)
-{
-	struct cpio_data cd = { NULL, 0, "" };
-	enum ucode_state ret;
+	if (!(cp.data && cp.size))
+		return NULL;
 
-	/* try built-in microcode first */
-	if (load_builtin_intel_microcode(&cd))
-		/*
-		 * Invalidate blobs as we might've gotten an initrd too,
-		 * supplied by the boot loader, by mistake or simply forgotten
-		 * there. That's fine, we ignore it since we've found builtin
-		 * microcode already.
-		 */
-		blbp->valid = false;
-	else {
-		ret = __scan_microcode_initrd(&cd, blbp);
-		if (ret != UCODE_OK)
-			return ret;
-	}
+	collect_cpu_info_early(uci);
 
-	return get_matching_model_microcode(blbp->start, cd.data, cd.size,
-					    mcs, mc_ptrs, uci);
+	return scan_microcode(cp.data, cp.size, uci, false);
 }
 
-static void __init
-_load_ucode_intel_bsp(struct mc_saved_data *mcs, unsigned long *mc_ptrs,
-		      struct ucode_blobs *blbp)
+void __init load_ucode_intel_bsp(void)
 {
+	struct microcode_intel *patch;
 	struct ucode_cpu_info uci;
-	enum ucode_state ret;
-
-	collect_cpu_info_early(&uci);
 
-	ret = scan_microcode(mcs, mc_ptrs, &uci, blbp);
-	if (ret != UCODE_OK)
+	patch = __load_ucode_intel(&uci);
+	if (!patch)
 		return;
 
-	ret = load_microcode(mcs, mc_ptrs, blbp->start, &uci);
-	if (ret != UCODE_OK)
-		return;
+	uci.mc = patch;
 
 	apply_microcode_early(&uci, true);
 }
 
-void __init load_ucode_intel_bsp(void)
+void load_ucode_intel_ap(void)
 {
-	struct ucode_blobs *blobs_p;
-	struct mc_saved_data *mcs;
-	unsigned long *ptrs;
+	struct microcode_intel *patch, **iup;
+	struct ucode_cpu_info uci;
 
-#ifdef CONFIG_X86_32
-	mcs	= (struct mc_saved_data *)__pa_nodebug(&mc_saved_data);
-	ptrs	= (unsigned long *)__pa_nodebug(&mc_tmp_ptrs);
-	blobs_p	= (struct ucode_blobs *)__pa_nodebug(&blobs);
-#else
-	mcs	= &mc_saved_data;
-	ptrs	= mc_tmp_ptrs;
-	blobs_p = &blobs;
-#endif
+	if (IS_ENABLED(CONFIG_X86_32))
+		iup = (struct microcode_intel **) __pa_nodebug(&intel_ucode_patch);
+	else
+		iup = &intel_ucode_patch;
+
+reget:
+	if (!*iup) {
+		patch = __load_ucode_intel(&uci);
+		if (!patch)
+			return;
+
+		*iup = patch;
+	}
 
-	_load_ucode_intel_bsp(mcs, ptrs, blobs_p);
+	uci.mc = *iup;
+
+	if (apply_microcode_early(&uci, true)) {
+		/* Mixed-silicon system? Try to refetch the proper patch: */
+		*iup = NULL;
+
+		goto reget;
+	}
 }
 
-void load_ucode_intel_ap(void)
+static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
 {
-	struct ucode_blobs *blobs_p;
-	unsigned long *ptrs, start = 0;
-	struct mc_saved_data *mcs;
-	struct ucode_cpu_info uci;
-	enum ucode_state ret;
+	struct microcode_header_intel *phdr;
+	struct ucode_patch *iter, *tmp;
 
-#ifdef CONFIG_X86_32
-	mcs	= (struct mc_saved_data *)__pa_nodebug(&mc_saved_data);
-	ptrs	= (unsigned long *)__pa_nodebug(mc_tmp_ptrs);
-	blobs_p	= (struct ucode_blobs *)__pa_nodebug(&blobs);
-#else
-	mcs	= &mc_saved_data;
-	ptrs	= mc_tmp_ptrs;
-	blobs_p = &blobs;
-#endif
-
-	/*
-	 * If there is no valid ucode previously saved in memory, no need to
-	 * update ucode on this AP.
-	 */
-	if (!mcs->num_saved)
-		return;
+	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
 
-	if (blobs_p->valid) {
-		start = blobs_p->start;
+		phdr = (struct microcode_header_intel *)iter->data;
 
-		/*
-		 * Pay attention to CONFIG_RANDOMIZE_MEMORY=y as it shuffles
-		 * physmem mapping too and there we have the initrd.
-		 */
-		start += PAGE_OFFSET - __PAGE_OFFSET_BASE;
-	}
+		if (phdr->rev <= uci->cpu_sig.rev)
+			continue;
 
-	collect_cpu_info_early(&uci);
-	ret = load_microcode(mcs, ptrs, start, &uci);
-	if (ret != UCODE_OK)
-		return;
+		if (!find_matching_signature(phdr,
+					     uci->cpu_sig.sig,
+					     uci->cpu_sig.pf))
+			continue;
 
-	apply_microcode_early(&uci, true);
+		return iter->data;
+	}
+	return NULL;
 }
 
 void reload_ucode_intel(void)
 {
+	struct microcode_intel *p;
 	struct ucode_cpu_info uci;
-	enum ucode_state ret;
-
-	if (!mc_saved_data.num_saved)
-		return;
 
 	collect_cpu_info_early(&uci);
 
-	ret = find_microcode_patch(mc_saved_data.mc_saved,
-				   mc_saved_data.num_saved, &uci);
-	if (ret != UCODE_OK)
+	p = find_patch(&uci);
+	if (!p)
 		return;
 
+	uci.mc = p;
+
 	apply_microcode_early(&uci, false);
 }
 
@@ -879,24 +779,6 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 	return 0;
 }
 
-/*
- * return 0 - no update found
- * return 1 - found update
- */
-static int get_matching_mc(struct microcode_intel *mc, int cpu)
-{
-	struct cpu_signature cpu_sig;
-	unsigned int csig, cpf, crev;
-
-	collect_cpu_info(cpu, &cpu_sig);
-
-	csig = cpu_sig.sig;
-	cpf = cpu_sig.pf;
-	crev = cpu_sig.rev;
-
-	return has_newer_microcode(mc, csig, cpf, crev);
-}
-
 static int apply_microcode_intel(int cpu)
 {
 	struct microcode_intel *mc;
@@ -911,16 +793,12 @@ static int apply_microcode_intel(int cpu)
 
 	uci = ucode_cpu_info + cpu;
 	mc = uci->mc;
-	if (!mc)
-		return 0;
-
-	/*
-	 * Microcode on this CPU could be updated earlier. Only apply the
-	 * microcode patch in mc when it is newer than the one on this
-	 * CPU.
-	 */
-	if (!get_matching_mc(mc, cpu))
-		return 0;
+	if (!mc) {
+		/* Look for a newer patch in our cache: */
+		mc = find_patch(uci);
+		if (!mc)
+			return 0;
+	}
 
 	/* write microcode via MSR 0x79 */
 	wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
@@ -962,7 +840,6 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
 	u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
 	int new_rev = uci->cpu_sig.rev;
 	unsigned int leftover = size;
-	enum ucode_state state = UCODE_OK;
 	unsigned int curr_mc_size = 0;
 	unsigned int csig, cpf;
 
@@ -1015,14 +892,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
 
 	if (leftover) {
 		vfree(new_mc);
-		state = UCODE_ERROR;
-		goto out;
+		return UCODE_ERROR;
 	}
 
-	if (!new_mc) {
-		state = UCODE_NFOUND;
-		goto out;
-	}