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

/*
 * Intel CPU Microcode Update Driver for Linux
 *
 * Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
 *		 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/processor.h>
#include <asm/tlbflush.h>
#include <asm/setup.h>
#include <asm/msr.h>

static unsigned long mc_saved_in_initrd[MAX_UCODE_COUNT];
static struct mc_saved_data {
	unsigned int mc_saved_count;
	struct microcode_intel **mc_saved;
} mc_saved_data;

static enum ucode_state
load_microcode_early(struct microcode_intel **saved,
		     unsigned int num_saved, struct ucode_cpu_info *uci)
{
	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 (!new_mc)
		return UCODE_NFOUND;

	uci->mc = (struct microcode_intel *)new_mc;
	return UCODE_OK;
}

static inline void
copy_initrd_ptrs(struct microcode_intel **mc_saved, unsigned long *initrd,
		  unsigned long off, int num_saved)
{
	int i;

	for (i = 0; i < num_saved; i++)
		mc_saved[i] = (struct microcode_intel *)(initrd[i] + off);
}

#ifdef CONFIG_X86_32
static void
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_nodebug(&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_nodebug(mc_saved_data->mc_saved + i);
		mc_saved_tmp[i] = (struct microcode_intel *)__pa_nodebug(p);
	}
}
#endif

static enum ucode_state
load_microcode(struct mc_saved_data *mc_saved_data, unsigned long *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) {
		copy_initrd_ptrs(mc_saved_tmp, initrd, initrd_start, count);

		return load_microcode_early(mc_saved_tmp, count, uci);
	} else {
#ifdef CONFIG_X86_32
		microcode_phys(mc_saved_tmp, mc_saved_data);
		return load_microcode_early(mc_saved_tmp, count, uci);
#else
		return load_microcode_early(mc_saved_data->mc_saved,
						    count, uci);
#endif
	}
}

/*
 * 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