[PATCH v2 05/10] x86/microcode_intel_early.c: Early update ucode on Intel's CPU

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

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/microcode.hex 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@xxxxxxxxx>
---
 arch/x86/kernel/microcode_intel_early.c |  438 +++++++++++++++++++++++++++++++
 1 files changed, 438 insertions(+), 0 deletions(-)
 create mode 100644 arch/x86/kernel/microcode_intel_early.c

diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
new file mode 100644
index 0000000..36b1df1
--- /dev/null
+++ b/arch/x86/kernel/microcode_intel_early.c
@@ -0,0 +1,438 @@
+/*
+ *	Intel CPU Microcode Update Driver for Linux
+ *
+ *	Copyright (C) 2012 Fenghua Yu <fenghua.yu@xxxxxxxxx>
+ *			   H Peter Anvin" <hpa@xxxxxxxxx>
+ *
+ *	This driver 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/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/earlycpio.h>
+#include <asm/msr.h>
+#include <asm/microcode_intel.h>
+#include <asm/processor.h>
+
+struct microcode_intel __initdata *mc_saved_in_initrd[MAX_UCODE_COUNT];
+struct mc_saved_data mc_saved_data;
+
+enum ucode_state
+generic_load_microcode_early(int cpu, 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;
+}
+EXPORT_SYMBOL_GPL(generic_load_microcode_early);
+
+static enum ucode_state __init
+load_microcode(struct mc_saved_data *mc_saved_data, int cpu)
+{
+	struct ucode_cpu_info *uci = mc_saved_data->ucode_cpu_info + cpu;
+
+	return generic_load_microcode_early(cpu, mc_saved_data->mc_saved,
+					    mc_saved_data->mc_saved_count, uci);
+}
+
+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;
+}
+
+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;
+
+	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_ERROR;
+
+	return UCODE_OK;
+}
+
+static void
+save_microcode(struct mc_saved_data *mc_saved_data,
+	       struct microcode_intel **mc_saved_src,
+	       unsigned int mc_saved_count)
+{
+	int i;
+	struct microcode_intel **mc_saved_p;
+
+	if (!mc_saved_count)
+		return;
+
+	mc_saved_p = vmalloc(mc_saved_count*sizeof(struct microcode_intel *));
+	if (!mc_saved_p)
+		return;
+
+	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] = vmalloc(mc_size);
+		if (mc_saved_src[i])
+			memcpy(mc_saved_p[i], mc, mc_size);
+	}
+
+	mc_saved_data->mc_saved = mc_saved_p;
+}
+
+/*
+ * Get microcode matching with BSP's model. Only CPU's with the same model as
+ * BSP can stay in the platform.
+ */
+enum ucode_state
+get_matching_model_microcode(int cpu, void *data, size_t size,
+			     struct mc_saved_data *mc_saved_data,
+			     struct microcode_intel **mc_saved_in_initrd,
+			     enum system_states system_state)
+{
+	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];
+	size_t mc_saved_size;
+	size_t mem_size;
+	unsigned int mc_saved_count = mc_saved_data->mc_saved_count;
+	struct ucode_cpu_info *uci = mc_saved_data->ucode_cpu_info + cpu;
+	int found = 0;
+	int i;
+
+	if (mc_saved_count) {
+		mem_size = mc_saved_count * sizeof(struct microcode_intel *);
+		memcpy(mc_saved_tmp, mc_saved_data->mc_saved, mem_size);
+	}
+
+	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;
+		if (matching_model_microcode(mc_header, uci->cpu_sig.sig) !=
+			 UCODE_OK) {
+			ucode_ptr += mc_size;
+			continue;
+		}
+
+		found = 0;
+		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_tmp[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_tmp[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_tmp[mc_saved_count++] =
+					 (struct microcode_intel *)ucode_ptr;
+
+		ucode_ptr += mc_size;
+	}
+
+	if (leftover) {
+		state = UCODE_ERROR;
+		goto out;
+	}
+
+	if (mc_saved_count == 0) {
+		state = UCODE_NFOUND;
+		goto out;
+	}
+
+	if (system_state == SYSTEM_RUNNING) {
+		vfree(mc_saved_data->mc_saved);
+		save_microcode(mc_saved_data, mc_saved_tmp, mc_saved_count);
+	} else {
+		mc_saved_size = sizeof(struct microcode_intel *) *
+				mc_saved_count;
+		memcpy(mc_saved_in_initrd, mc_saved_tmp, mc_saved_size);
+		mc_saved_data->mc_saved = mc_saved_in_initrd;
+	}
+
+	mc_saved_data->mc_saved_count = mc_saved_count;
+out:
+	return state;
+}
+EXPORT_SYMBOL_GPL(get_matching_model_microcode);
+
+#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 = {0, 0, 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;
+
+	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);
+	}
+
+	/* 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;
+}
+
+static __init enum ucode_state
+scan_microcode(unsigned long start, unsigned long end,
+		struct mc_saved_data *mc_saved_data,
+		struct microcode_intel **mc_saved_in_initrd)
+{
+	unsigned int size = end - start + 1;
+	struct cpio_data cd = { 0, 0 };
+	char ucode_name[] = "kernel/x86/microcode/GenuineIntel.bin";
+	long offset = 0;
+
+	cd = find_cpio_data(ucode_name, (void *)start, size, &offset);
+	if (!cd.data)
+		return UCODE_ERROR;
+
+	return get_matching_model_microcode(0, cd.data, cd.size, mc_saved_data,
+					 mc_saved_in_initrd, SYSTEM_BOOTING);
+}
+
+static int __init
+apply_microcode_early(struct mc_saved_data *mc_saved_data, int cpu)
+{
+	struct ucode_cpu_info *uci = mc_saved_data->ucode_cpu_info + cpu;
+	struct microcode_intel *mc_intel;
+	unsigned int val[2];
+
+	/* We should bind the task to the CPU */
+	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;
+
+	uci->cpu_sig.rev = val[1];
+
+	return 0;
+}
+
+#ifdef CONFIG_X86_32
+static void __init map_mc_saved(struct mc_saved_data *mc_saved_data,
+				struct microcode_intel **mc_saved_in_initrd)
+{
+	int i;
+
+	if (mc_saved_data->mc_saved) {
+		for (i = 0; i < mc_saved_data->mc_saved_count; i++)
+			mc_saved_data->mc_saved[i] =
+					 __va(mc_saved_data->mc_saved[i]);
+
+		mc_saved_data->mc_saved = __va(mc_saved_data->mc_saved);
+	}
+
+	if (mc_saved_data->ucode_cpu_info->mc)
+		mc_saved_data->ucode_cpu_info->mc =
+				 __va(mc_saved_data->ucode_cpu_info->mc);
+	mc_saved_data->ucode_cpu_info = __va(mc_saved_data->ucode_cpu_info);
+}
+#else
+static inline void __init map_mc_saved(struct mc_saved_data *mc_saved_data,
+				struct microcode_intel **mc_saved_in_initrd)
+{
+}
+#endif
+
+void __init save_microcode_in_initrd(struct mc_saved_data *mc_saved_data,
+		 struct microcode_intel **mc_saved_in_initrd)
+{
+	unsigned int count = mc_saved_data->mc_saved_count;
+
+	save_microcode(mc_saved_data, mc_saved_in_initrd, count);
+}
+
+static void __init
+_load_ucode_intel_bsp(struct mc_saved_data *mc_saved_data,
+		      struct microcode_intel **mc_saved_in_initrd,
+		      unsigned long initrd_start, unsigned long initrd_end)
+{
+	int cpu = 0;
+
+#ifdef CONFIG_X86_64
+	mc_saved_data->ucode_cpu_info = ucode_cpu_info_early;
+#else
+	mc_saved_data->ucode_cpu_info =
+			(struct ucode_cpu_info *)__pa(ucode_cpu_info_early);
+#endif
+	collect_cpu_info_early(mc_saved_data->ucode_cpu_info + cpu);
+	scan_microcode(initrd_start, initrd_end, mc_saved_data,
+		       mc_saved_in_initrd);
+	load_microcode(mc_saved_data, cpu);
+	apply_microcode_early(mc_saved_data, cpu);
+	map_mc_saved(mc_saved_data, mc_saved_in_initrd);
+}
+
+void __init
+load_ucode_intel_bsp(char *real_mode_data)
+{
+	u64 ramdisk_image, ramdisk_size, ramdisk_end;
+	unsigned long initrd_start, initrd_end;
+	struct boot_params *boot_params;
+
+	boot_params = (struct boot_params *)real_mode_data;
+	ramdisk_image = boot_params->hdr.ramdisk_image;
+	ramdisk_size  = boot_params->hdr.ramdisk_size;
+
+#ifdef CONFIG_X86_64
+	ramdisk_end  = PAGE_ALIGN(ramdisk_image + ramdisk_size);
+	initrd_start = ramdisk_image + PAGE_OFFSET;
+	initrd_end = initrd_start + ramdisk_size;
+	_load_ucode_intel_bsp(&mc_saved_data, mc_saved_in_initrd,
+			      initrd_start, initrd_end);
+#else
+	ramdisk_end  = ramdisk_image + ramdisk_size;
+	initrd_start = ramdisk_image;
+	initrd_end = initrd_start + ramdisk_size;
+	_load_ucode_intel_bsp((struct mc_saved_data *)__pa(&mc_saved_data),
+			(struct microcode_intel **)__pa(mc_saved_in_initrd),
+			initrd_start, initrd_end);
+#endif
+}
+
+void __cpuinit load_ucode_intel_ap(void)
+{
+	int cpu = smp_processor_id();
+
+	/*
+	 * If BSP doesn't find valid ucode and save it in memory, no need to
+	 * update ucode on this AP.
+	 */
+	if (!mc_saved_data.mc_saved)
+		return;
+
+	collect_cpu_info_early(mc_saved_data.ucode_cpu_info + cpu);
+	load_microcode(&mc_saved_data, cpu);
+	apply_microcode_early(&mc_saved_data, cpu);
+}
-- 
1.7.2

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