path: root/arch/x86/kernel/cpu/microcode/intel.c

/*
 * Intel CPU Microcode Update Driver for Linux
 *
 * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
 *		 2006 Shaohua Li <shaohua.li@intel.com>
 *
 * Intel CPU microcode early update for Linux
 *
 * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
 *		      H Peter Anvin" <hpa@zytor.com>
 *
 * 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.
 */

/*
 * This needs to be before all headers so that pr_debug in printk.h doesn't turn
 * printk calls into no_printk().
 *
 *#define DEBUG
 */
#define pr_fmt(fmt) "microcode: " fmt

#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>
#include <linux/cpu.h>
#include <linux/mm.h>

#include <asm/microcode_intel.h>
#include <asm/intel-family.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/setup.h>
#include <asm/msr.h>

static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";

/* Current microcode patch used in early patching on the APs. */
static struct microcode_intel *intel_ucode_patch;

/* last level cache size per core */
static int llc_size_per_core;

static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
					unsigned int s2, unsigned int p2)
{
	if (s1 != s2)
		return false;

	/* Processor flags are either both 0 ... */
	if (!p1 && !p2)
		return true;

	/* ... or they intersect. */
	return p1 & p2;
}

/*
 * 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;

	if (cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
		return 1;

	/* Look for ext. headers: */
	if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
		return 0;

	ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
	ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;

	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;
}

/*
 * 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 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 bool microcode_matches(struct microcode_header_intel *mc_header,
			      unsigned long sig)
{
	unsigned long total_size = get_totalsize(mc_header);
	unsigned long data_size = get_datasize(mc_header);
	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);

	fam_ucode   = x86_family(mc_header->sig);
	model_ucode = x86_model(mc_header->sig);

	if (fam == fam_ucode && model == model_ucode)
		return true;

	/* Look for ext. headers: */
	if (total_size <= data_size + MC_HEADER_SIZE)
		return false;

	ext_header   = (void *) mc_header + data_size + MC_HEADER_SIZE;
	ext_sig      = (void *)ext_header + EXT_HEADER_SIZE;
	ext_sigcount = ext_header->count;

	for (i = 0; i < ext_sigcount; i++) {
		fam_ucode   = x86_family(ext_sig->sig);
		model_ucode = x86_model(ext_sig->sig);

		if (fam == fam_ucode && model == model_ucode)
			return true;

		ext_sig++;
	}
	return false;
}

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(void *data, unsigned int size)
{
	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 (find_matching_signature(data