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

/*

 *	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);