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  • Peter Zijlstra's avatar
    x86/microcode: Dont abuse the TLB-flush interface · 23cb7d46
    Peter Zijlstra authored
    
    Commit:
    
      ec400dde ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
    
    ... grubbed into tlbflush internals without coherent explanation.
    
    Since it says its a precaution and the SDM doesn't mention anything like
    this, take it out back.
    
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Brian Gerst <brgerst@gmail.com>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: David Laight <David.Laight@aculab.com>
    Cc: Denys Vlasenko <dvlasenk@redhat.com>
    Cc: Eduardo Valentin <eduval@amazon.com>
    Cc: Greg KH <gregkh@linuxfoundation.org>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Will Deacon <will.deacon@arm.com>
    Cc: aliguori@amazon.com
    Cc: daniel.gruss@iaik.tugraz.at
    Cc: fenghua.yu@intel.com
    Cc: hughd@google.com
    Cc: keescook@google.com
    Cc: linux-mm@kvack.org
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    23cb7d46
intel.c 21.50 KiB
/*
 * 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;

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;