[tip:x86/microcode] x86/microcode_intel_early.c: Early update ucode on Intel's CPU

[tip-bot for Fenghua Yu <fenghua.yu@intel.com>]

Commit-ID:  ec400ddeff200b068ddc6c70f7321f49ecf32ed5
Gitweb:     http://git.kernel.org/tip/ec400ddeff200b068ddc6c70f7321f49ecf32ed5
Author:     Fenghua Yu <fenghua.yu@intel.com>
AuthorDate: Thu, 20 Dec 2012 23:44:28 -0800
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Thu, 31 Jan 2013 13:19:18 -0800

x86/microcode_intel_early.c: Early update ucode on Intel's CPU

Implementation of early update ucode on Intel's CPU.

load_ucode_intel_bsp() scans ucode in initrd image file which is a cpio format
ucode followed by ordinary initrd image file. The binary ucode file is stored
in kernel/x86/microcode/GenuineIntel.bin in the cpio data. All ucode
patches with the same model as BSP are saved in memory. A matching ucode patch
is updated on BSP.

load_ucode_intel_ap() reads saved ucoded patches and updates ucode on AP.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/kernel/microcode_intel_early.c | 796 ++++++++++++++++++++++++++++++++
 1 file changed, 796 insertions(+)

diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
new file mode 100644
index 0000000..7890bc8
--- /dev/null
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -0,0 +1,796 @@
+/*
+ *	Intel CPU microcode early update for Linux
+ *
+ *	Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
+ *			   H Peter Anvin" <hpa@zytor.com>
+ *
+ *	This allows to early upgrade microcode on Intel processors
+ *	belonging to IA-32 family - PentiumPro, Pentium II,
+ *	Pentium III, Xeon, Pentium 4, etc.
+ *
+ *	Reference: Section 9.11 of Volume 3, IA-32 Intel Architecture
+ *	Software Developer's Manual.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/earlycpio.h>
+#include <linux/initrd.h>
+#include <linux/cpu.h>
+#include <asm/msr.h>
+#include <asm/microcode_intel.h>
+#include <asm/processor.h>
+#include <asm/tlbflush.h>
+#include <asm/setup.h>
+
+unsigned long mc_saved_in_initrd[MAX_UCODE_COUNT];
+struct mc_saved_data {
+	unsigned int mc_saved_count;
+	struct microcode_intel **mc_saved;
+} mc_saved_data;
+
+static enum ucode_state __cpuinit
+generic_load_microcode_early(struct microcode_intel **mc_saved_p,
+			     unsigned int mc_saved_count,
+			     struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *ucode_ptr, *new_mc = NULL;
+	int new_rev = uci->cpu_sig.rev;
+	enum ucode_state state = UCODE_OK;
+	unsigned int mc_size;
+	struct microcode_header_intel *mc_header;
+	unsigned int csig = uci->cpu_sig.sig;
+	unsigned int cpf = uci->cpu_sig.pf;
+	int i;
+
+	for (i = 0; i < mc_saved_count; i++) {
+		ucode_ptr = mc_saved_p[i];
+
+		mc_header = (struct microcode_header_intel *)ucode_ptr;
+		mc_size = get_totalsize(mc_header);
+		if (get_matching_microcode(csig, cpf, ucode_ptr, new_rev)) {
+			new_rev = mc_header->rev;
+			new_mc  = ucode_ptr;
+		}
+	}
+
+	if (!new_mc) {
+		state = UCODE_NFOUND;
+		goto out;
+	}
+
+	uci->mc = (struct microcode_intel *)new_mc;
+out:
+	return state;
+}
+
+static void __cpuinit
+microcode_pointer(struct microcode_intel **mc_saved,
+		  unsigned long *mc_saved_in_initrd,
+		  unsigned long initrd_start, int mc_saved_count)
+{
+	int i;
+
+	for (i = 0; i < mc_saved_count; i++)
+		mc_saved[i] = (struct microcode_intel *)
+			      (mc_saved_in_initrd[i] + initrd_start);
+}
+
+#ifdef CONFIG_X86_32
+static void __cpuinit
+microcode_phys(struct microcode_intel **mc_saved_tmp,
+	       struct mc_saved_data *mc_saved_data)
+{
+	int i;
+	struct microcode_intel ***mc_saved;
+
+	mc_saved = (struct microcode_intel ***)
+		   __pa_symbol(&mc_saved_data->mc_saved);
+	for (i = 0; i < mc_saved_data->mc_saved_count; i++) {
+		struct microcode_intel *p;
+
+		p = *(struct microcode_intel **)
+			__pa(mc_saved_data->mc_saved + i);
+		mc_saved_tmp[i] = (struct microcode_intel *)__pa(p);
+	}
+}
+#endif
+
+static enum ucode_state __cpuinit
+load_microcode(struct mc_saved_data *mc_saved_data,
+	       unsigned long *mc_saved_in_initrd,
+	       unsigned long initrd_start,
+	       struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
+	unsigned int count = mc_saved_data->mc_saved_count;
+
+	if (!mc_saved_data->mc_saved) {
+		microcode_pointer(mc_saved_tmp, mc_saved_in_initrd,
+				  initrd_start, count);
+
+		return generic_load_microcode_early(mc_saved_tmp, count, uci);
+	} else {
+#ifdef CONFIG_X86_32
+		microcode_phys(mc_saved_tmp, mc_saved_data);
+		return generic_load_microcode_early(mc_saved_tmp, count, uci);
+#else
+		return generic_load_microcode_early(mc_saved_data->mc_saved,
+						    count, uci);
+#endif
+	}
+}
+
+static u8 get_x86_family(unsigned long sig)
+{
+	u8 x86;
+
+	x86 = (sig >> 8) & 0xf;
+
+	if (x86 == 0xf)
+		x86 += (sig >> 20) & 0xff;
+
+	return x86;
+}
+
+static u8 get_x86_model(unsigned long sig)
+{
+	u8 x86, x86_model;
+
+	x86 = get_x86_family(sig);
+	x86_model = (sig >> 4) & 0xf;
+
+	if (x86 == 0x6 || x86 == 0xf)
+		x86_model += ((sig >> 16) & 0xf) << 4;
+
+	return x86_model;
+}
+
+/*
+ * Given CPU signature and a microcode patch, this function finds if the
+ * microcode patch has matching family and model with the CPU.
+ */
+static enum ucode_state
+matching_model_microcode(struct microcode_header_intel *mc_header,
+			unsigned long sig)
+{
+	u8 x86, x86_model;
+	u8 x86_ucode, x86_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_signature *ext_sig;
+
+	x86 = get_x86_family(sig);
+	x86_model = get_x86_model(sig);
+
+	x86_ucode = get_x86_family(mc_header->sig);
+	x86_model_ucode = get_x86_model(mc_header->sig);
+
+	if (x86 == x86_ucode && x86_model == x86_model_ucode)
+		return UCODE_OK;
+
+	/* Look for ext. headers: */
+	if (total_size <= data_size + MC_HEADER_SIZE)
+		return UCODE_NFOUND;
+
+	ext_header = (struct extended_sigtable *)
+		     mc_header + data_size + MC_HEADER_SIZE;
+	ext_sigcount = ext_header->count;
+	ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
+
+	for (i = 0; i < ext_sigcount; i++) {
+		x86_ucode = get_x86_family(ext_sig->sig);
+		x86_model_ucode = get_x86_model(ext_sig->sig);
+
+		if (x86 == x86_ucode && x86_model == x86_model_ucode)
+			return UCODE_OK;
+
+		ext_sig++;
+	}
+
+	return UCODE_NFOUND;
+}
+
+static int
+save_microcode(struct mc_saved_data *mc_saved_data,
+	       struct microcode_intel **mc_saved_src,
+	       unsigned int mc_saved_count)
+{
+	int i, j;
+	struct microcode_intel **mc_saved_p;
+	int ret;
+
+	if (!mc_saved_count)
+		return -EINVAL;
+
+	/*
+	 * Copy new microcode data.
+	 */
+	mc_saved_p = kmalloc(mc_saved_count*sizeof(struct microcode_intel *),
+			     GFP_KERNEL);
+	if (!mc_saved_p)
+		return -ENOMEM;
+
+	for (i = 0; i < mc_saved_count; i++) {
+		struct microcode_intel *mc = mc_saved_src[i];
+		struct microcode_header_intel *mc_header = &mc->hdr;
+		unsigned long mc_size = get_totalsize(mc_header);
+		mc_saved_p[i] = kmalloc(mc_size, GFP_KERNEL);
+		if (!mc_saved_p[i]) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		if (!mc_saved_src[i]) {
+			ret = -EINVAL;
+			goto err;
+		}
+		memcpy(mc_saved_p[i], mc, mc_size);
+	}
+
+	/*
+	 * Point to newly saved microcode.
+	 */
+	mc_saved_data->mc_saved = mc_saved_p;
+	mc_saved_data->mc_saved_count = mc_saved_count;
+
+	return 0;
+
+err:
+	for (j = 0; j <= i; j++)
+		kfree(mc_saved_p[j]);
+	kfree(mc_saved_p);
+
+	return ret;
+}
+
+/*
+ * 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.
+ */
+static void _save_mc(struct microcode_intel **mc_saved, u8 *ucode_ptr,
+		     unsigned int *mc_saved_count_p)
+{
+	int i;
+	int found = 0;
+	unsigned int mc_saved_count = *mc_saved_count_p;
+	struct microcode_header_intel *mc_header;
+
+	mc_header = (struct microcode_header_intel *)ucode_ptr;
+	for (i = 0; i < mc_saved_count; i++) {
+		unsigned int sig, pf;
+		unsigned int new_rev;
+		struct microcode_header_intel *mc_saved_header =
+			     (struct microcode_header_intel *)mc_saved[i];
+		sig = mc_saved_header->sig;
+		pf = mc_saved_header->pf;
+		new_rev = mc_header->rev;
+
+		if (get_matching_sig(sig, pf, ucode_ptr, new_rev)) {
+			found = 1;
+			if (update_match_revision(mc_header, new_rev)) {
+				/*
+				 * Found an older ucode saved before.
+				 * Replace the older one with this newer
+				 * one.
+				 */
+				mc_saved[i] =
+					(struct microcode_intel *)ucode_ptr;
+				break;
+			}
+		}
+	}
+	if (i >= mc_saved_count && !found)
+		/*
+		 * This ucode is first time discovered in ucode file.
+		 * Save it to memory.
+		 */
+		mc_saved[mc_saved_count++] =
+				 (struct microcode_intel *)ucode_ptr;
+
+	*mc_saved_count_p = mc_saved_count;
+}
+
+/*
+ * 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(int cpu, unsigned long start,
+			     void *data, size_t size,
+			     struct mc_saved_data *mc_saved_data,
+			     unsigned long *mc_saved_in_initrd,
+			     struct ucode_cpu_info *uci)
+{
+	u8 *ucode_ptr = data;
+	unsigned int leftover = size;
+	enum ucode_state state = UCODE_OK;
+	unsigned int mc_size;
+	struct microcode_header_intel *mc_header;
+	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
+	unsigned int mc_saved_count = mc_saved_data->mc_saved_count;
+	int i;
+
+	while (leftover) {
+		mc_header = (struct microcode_header_intel *)ucode_ptr;
+
+		mc_size = get_totalsize(mc_header);
+		if (!mc_size || mc_size > leftover ||
+			microcode_sanity_check(ucode_ptr, 0) < 0)
+			break;
+
+		leftover -= 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;
+			continue;
+		}
+
+		_save_mc(mc_saved_tmp, ucode_ptr, &mc_saved_count);
+
+		ucode_ptr += mc_size;
+	}
+
+	if (leftover) {
+		state = UCODE_ERROR;
+		goto out;
+	}
+
+	if (mc_saved_count == 0) {
+		state = UCODE_NFOUND;
+		goto out;
+	}
+
+	for (i = 0; i < mc_saved_count; i++)
+		mc_saved_in_initrd[i] = (unsigned long)mc_saved_tmp[i] - start;
+
+	mc_saved_data->mc_saved_count = mc_saved_count;
+out:
+	return state;
+}
+
+#define native_rdmsr(msr, val1, val2)		\
+do {						\
+	u64 __val = native_read_msr((msr));	\
+	(void)((val1) = (u32)__val);		\
+	(void)((val2) = (u32)(__val >> 32));	\
+} while (0)
+
+#define native_wrmsr(msr, low, high)		\
+	native_write_msr(msr, low, high);
+
+static int __cpuinit collect_cpu_info_early(struct ucode_cpu_info *uci)
+{
+	unsigned int val[2];
+	u8 x86, x86_model;
+	struct cpu_signature csig;
+	unsigned int eax, ebx, ecx, edx;
+
+	csig.sig = 0;
+	csig.pf = 0;
+	csig.rev = 0;
+
+	memset(uci, 0, sizeof(*uci));
+
+	eax = 0x00000001;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	csig.sig = eax;
+
+	x86 = get_x86_family(csig.sig);
+	x86_model = get_x86_model(csig.sig);
+
+	if ((x86_model >= 5) || (x86 > 6)) {
+		/* get processor flags from MSR 0x17 */
+		native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+		csig.pf = 1 << ((val[1] >> 18) & 7);
+	}
+	native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+
+	/* As documented in the SDM: Do a CPUID 1 here */
+	sync_core();
+
+	/* get the current revision from MSR 0x8B */
+	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+
+	csig.rev = val[1];
+
+	uci->cpu_sig = csig;
+	uci->valid = 1;
+
+	return 0;
+}
+
+#ifdef DEBUG
+static void __ref show_saved_mc(void)
+{
+	int i, j;
+	unsigned int sig, pf, rev, total_size, data_size, date;
+	struct ucode_cpu_info uci;
+
+	if (mc_saved_data.mc_saved_count == 0) {
+		pr_debug("no micorcode data saved.\n");
+		return;
+	}
+	pr_debug("Total microcode saved: %d\n", mc_saved_data.mc_saved_count);
+
+	collect_cpu_info_early(&uci);
+
+	sig = uci.cpu_sig.sig;
+	pf = uci.cpu_sig.pf;
+	rev = uci.cpu_sig.rev;
+	pr_debug("CPU%d: sig=0x%x, pf=0x%x, rev=0x%x\n",
+		 smp_processor_id(), sig, pf, rev);
+
+	for (i = 0; i < mc_saved_data.mc_saved_count; i++) {
+		struct microcode_header_intel *mc_saved_header;
+		struct extended_sigtable *ext_header;
+		int ext_sigcount;
+		struct extended_signature *ext_sig;
+
+		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;
+
+		pr_debug("mc_saved[%d]: sig=0x%x, pf=0x%x, rev=0x%x, toal size=0x%x, date = %04x-%02x-%02x\n",
+			 i, sig, pf, rev, total_size,
+			 date & 0xffff,
+			 date >> 24,
+			 (date >> 16) & 0xff);
+
+		/* Look for ext. headers: */
+		if (total_size <= data_size + MC_HEADER_SIZE)
+			continue;
+
+		ext_header = (struct extended_sigtable *)
+			     mc_saved_header + data_size + MC_HEADER_SIZE;
+		ext_sigcount = ext_header->count;
+		ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
+
+		for (j = 0; j < ext_sigcount; j++) {
+			sig = ext_sig->sig;
+			pf = ext_sig->pf;
+
+			pr_debug("\tExtended[%d]: sig=0x%x, pf=0x%x\n",
+				 j, sig, pf);
+
+			ext_sig++;
+		}
+
+	}
+}
+#else
+static inline void show_saved_mc(void)
+{
+}
+#endif
+
+#if defined(CONFIG_MICROCODE_INTEL_EARLY) && defined(CONFIG_HOTPLUG_CPU)
+/*
+ * 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.
+ */
+int save_mc_for_early(u8 *mc)
+{
+	struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT];
+	unsigned int mc_saved_count_init;
+	unsigned int mc_saved_count;
+	struct microcode_intel **mc_saved;
+	int ret = 0;
+	int i;
+
+	/*
+	 * Hold hotplug lock so mc_saved_data is not accessed by a CPU in
+	 * hotplug.
+	 */
+	cpu_hotplug_driver_lock();
+
+	mc_saved_count_init = mc_saved_data.mc_saved_count;
+	mc_saved_count = mc_saved_data.mc_saved_count;
+	mc_saved = mc_saved_data.mc_saved;
+
+	if (mc_saved && mc_saved_count)
+		memcpy(mc_saved_tmp, mc_saved,
+		       mc_saved_count * sizeof(struct mirocode_intel *));
+	/*
+	 * Save the microcode patch mc in mc_save_tmp structure if it's a newer
+	 * version.
+	 */
+
+	_save_mc(mc_saved_tmp, mc, &mc_saved_count);
+
+	/*
+	 * Save the mc_save_tmp in global mc_saved_data.
+	 */
+	ret = save_microcode(&mc_saved_data, mc_saved_tmp, mc_saved_count);
+	if (ret) {
+		pr_err("Can not save microcode patch.\n");
+		goto out;
+	}
+
+	show_saved_mc();
+
+	/*
+	 * Free old saved microcod data.
+	 */
+	if (mc_saved) {
+		for (i = 0; i < mc_saved_count_init; i++)
+			kfree(mc_saved[i]);
+		kfree(mc_saved);
+	}
+
+out:
+	cpu_hotplug_driver_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(save_mc_for_early);
+#endif
+
+static __initdata char ucode_name[] = "kernel/x86/microcode/GenuineIntel.bin";
+static __init enum ucode_state
+scan_microcode(unsigned long start, unsigned long end,
+		struct mc_saved_data *mc_saved_data,
+		unsigned long *mc_saved_in_initrd,
+		struct ucode_cpu_info *uci)
+{
+	unsigned int size = end - start + 1;
+	struct cpio_data cd;
+	long offset = 0;
+#ifdef CONFIG_X86_32
+	char *p = (char *)__pa_symbol(ucode_name);
+#else
+	char *p = ucode_name;
+#endif
+
+	cd.data = NULL;
+	cd.size = 0;
+
+	cd = find_cpio_data(p, (void *)start, size, &offset);
+	if (!cd.data)
+		return UCODE_ERROR;
+
+
+	return get_matching_model_microcode(0, start, cd.data, cd.size,
+					    mc_saved_data, mc_saved_in_initrd,
+					    uci);
+}
+
+/*
+ * Print ucode update info.
+ */
+static void __cpuinit
+print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
+{
+	int cpu = smp_processor_id();
+
+	pr_info("CPU%d microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
+		cpu,
+		uci->cpu_sig.rev,
+		date & 0xffff,
+		date >> 24,
+		(date >> 16) & 0xff);
+}
+
+#ifdef CONFIG_X86_32
+
+static int delay_ucode_info;
+static int current_mc_date;
+
+/*
+ * Print early updated ucode info after printk works. This is delayed info dump.
+ */
+void __cpuinit show_ucode_info_early(void)
+{
+	struct ucode_cpu_info uci;
+
+	if (delay_ucode_info) {
+		collect_cpu_info_early(&uci);
+		print_ucode_info(&uci, current_mc_date);
+		delay_ucode_info = 0;
+	}
+}
+
+/*
+ * 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
+ * show_ucode_info_early() until printk() works.
+ */
+static void __cpuinit print_ucode(struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *mc_intel;
+	int *delay_ucode_info_p;
+	int *current_mc_date_p;
+
+	mc_intel = uci->mc;
+	if (mc_intel == NULL)
+		return;
+
+	delay_ucode_info_p = (int *)__pa_symbol(&delay_ucode_info);
+	current_mc_date_p = (int *)__pa_symbol(&current_mc_date);
+
+	*delay_ucode_info_p = 1;
+	*current_mc_date_p = mc_intel->hdr.date;
+}
+#else
+
+/*
+ * Flush global tlb. We only do this in x86_64 where paging has been enabled
+ * already and PGE should be enabled as well.
+ */
+static inline void __cpuinit flush_tlb_early(void)
+{
+	__native_flush_tlb_global_irq_disabled();
+}
+
+static inline void __cpuinit print_ucode(struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *mc_intel;
+
+	mc_intel = uci->mc;
+	if (mc_intel == NULL)
+		return;
+
+	print_ucode_info(uci, mc_intel->hdr.date);
+}
+#endif
+
+static int apply_microcode_early(struct mc_saved_data *mc_saved_data,
+				 struct ucode_cpu_info *uci)
+{
+	struct microcode_intel *mc_intel;
+	unsigned int val[2];
+
+	mc_intel = uci->mc;
+	if (mc_intel == NULL)
+		return 0;
+
+	/* write microcode via MSR 0x79 */
+	native_wrmsr(MSR_IA32_UCODE_WRITE,
+	      (unsigned long) mc_intel->bits,
+	      (unsigned long) mc_intel->bits >> 16 >> 16);
+	native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+
+	/* As documented in the SDM: Do a CPUID 1 here */
+	sync_core();
+
+	/* get the current revision from MSR 0x8B */
+	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+	if (val[1] != mc_intel->hdr.rev)
+		return -1;
+
+#ifdef CONFIG_X86_64
+	/* Flush global tlb. This is precaution. */
+	flush_tlb_early();
+#endif
+	uci->cpu_sig.rev = val[1];
+
+	print_ucode(uci);
+
+	return 0;
+}
+
+/*
+ * This function converts microcode patch offsets previously stored in
+ * mc_saved_in_initrd to pointers and stores the pointers in mc_saved_data.
+ */
+int __init save_microcode_in_initrd(void)
+{
+	unsigned int count = mc_saved_data.mc_saved_count;
+	struct microcode_intel *mc_saved[MAX_UCODE_COUNT];
+	int ret = 0;
+
+	if (count == 0)
+		return ret;
+
+	microcode_pointer(mc_saved, mc_saved_in_initrd, initrd_start, count);
+	ret = save_microcode(&mc_saved_data, mc_saved, count);
+	if (ret)
+		pr_err("Can not save microcod patches from initrd");
+
+	show_saved_mc();
+
+	return ret;
+}
+
+static void __init
+_load_ucode_intel_bsp(struct mc_saved_data *mc_saved_data,
+		      unsigned long *mc_saved_in_initrd,
+		      unsigned long initrd_start_early,
+		      unsigned long initrd_end_early,
+		      struct ucode_cpu_info *uci)
+{
+	collect_cpu_info_early(uci);
+	scan_microcode(initrd_start_early, initrd_end_early, mc_saved_data,
+		       mc_saved_in_initrd, uci);
+	load_microcode(mc_saved_data, mc_saved_in_initrd,
+		       initrd_start_early, uci);
+	apply_microcode_early(mc_saved_data, uci);
+}
+
+void __init
+load_ucode_intel_bsp(void)
+{
+	u64 ramdisk_image, ramdisk_size;
+	unsigned long initrd_start_early, initrd_end_early;
+	struct ucode_cpu_info uci;
+#ifdef CONFIG_X86_32
+	struct boot_params *boot_params_p;
+
+	boot_params_p = (struct boot_params *)__pa_symbol(&boot_params);
+	ramdisk_image = boot_params_p->hdr.ramdisk_image;
+	ramdisk_size  = boot_params_p->hdr.ramdisk_size;
+	initrd_start_early = ramdisk_image;
+	initrd_end_early = initrd_start_early + ramdisk_size;
+
+	_load_ucode_intel_bsp(
+		(struct mc_saved_data *)__pa_symbol(&mc_saved_data),
+		(unsigned long *)__pa_symbol(&mc_saved_in_initrd),
+		initrd_start_early, initrd_end_early, &uci);
+#else
+	ramdisk_image = boot_params.hdr.ramdisk_image;
+	ramdisk_size  = boot_params.hdr.ramdisk_size;
+	initrd_start_early = ramdisk_image + PAGE_OFFSET;
+	initrd_end_early = initrd_start_early + ramdisk_size;
+
+	_load_ucode_intel_bsp(&mc_saved_data, mc_saved_in_initrd,
+			      initrd_start_early, initrd_end_early, &uci);
+#endif
+}
+
+void __cpuinit load_ucode_intel_ap(void)
+{
+	struct mc_saved_data *mc_saved_data_p;
+	struct ucode_cpu_info uci;
+	unsigned long *mc_saved_in_initrd_p;
+	unsigned long initrd_start_addr;
+#ifdef CONFIG_X86_32
+	unsigned long *initrd_start_p;
+
+	mc_saved_in_initrd_p =
+		(unsigned long *)__pa_symbol(mc_saved_in_initrd);
+	mc_saved_data_p = (struct mc_saved_data *)__pa_symbol(&mc_saved_data);
+	initrd_start_p = (unsigned long *)__pa_symbol(&initrd_start);
+	initrd_start_addr = (unsigned long)__pa_symbol(*initrd_start_p);
+#else
+	mc_saved_data_p = &mc_saved_data;
+	mc_saved_in_initrd_p = mc_saved_in_initrd;
+	initrd_start_addr = initrd_start;
+#endif
+
+	/*
+	 * If there is no valid ucode previously saved in memory, no need to
+	 * update ucode on this AP.
+	 */
+	if (mc_saved_data_p->mc_saved_count == 0)
+		return;
+
+	collect_cpu_info_early(&uci);
+	load_microcode(mc_saved_data_p, mc_saved_in_initrd_p,
+		       initrd_start_addr, &uci);
+	apply_microcode_early(mc_saved_data_p, &uci);
+}