path: root/arch/x86/kernel/cpu/mtrr/cleanup.c

/*
 * MTRR (Memory Type Range Register) cleanup
 *
 *  Copyright (C) 2009 Yinghai Lu
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/kvm_para.h>
#include <linux/range.h>

#include <asm/processor.h>
#include <asm/e820/api.h>
#include <asm/mtrr.h>
#include <asm/msr.h>

#include "mtrr.h"

struct var_mtrr_range_state {
	unsigned long	base_pfn;
	unsigned long	size_pfn;
	mtrr_type	type;
};

struct var_mtrr_state {
	unsigned long	range_startk;
	unsigned long	range_sizek;
	unsigned long	chunk_sizek;
	unsigned long	gran_sizek;
	unsigned int	reg;
};

/* Should be related to MTRR_VAR_RANGES nums */
#define RANGE_NUM				256

static struct range __initdata		range[RANGE_NUM];
static int __initdata				nr_range;

static struct var_mtrr_range_state __initdata	range_state[RANGE_NUM];

#define BIOS_BUG_MSG \
	"WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n"

static int __init
x86_get_mtrr_mem_range(struct range *range, int nr_range,
		       unsigned long extra_remove_base,
		       unsigned long extra_remove_size)
{
	unsigned long base, size;
	mtrr_type type;
	int i;

	for (i = 0; i < num_var_ranges; i++) {
		type = range_state[i].type;
		if (type != MTRR_TYPE_WRBACK)
			continue;
		base = range_state[i].base_pfn;
		size = range_state[i].size_pfn;
		nr_range = add_range_with_merge(range, RANGE_NUM, nr_range,
						base, base + size);
	}

	Dprintk("After WB checking\n");
	for (i = 0; i < nr_range; i++)
		Dprintk("MTRR MAP PFN: %016llx - %016llx\n",
			 range[i].start, range[i].end);

	/* Take out UC ranges: */
	for (i = 0; i < num_var_ranges; i++) {
		type = range_state[i].type;
		if (type != MTRR_TYPE_UNCACHABLE &&
		    type != MTRR_TYPE_WRPROT)
			continue;
		size = range_state[i].size_pfn;
		if (!size)
			continue;
		base = range_state[i].base_pfn;
		if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed &&
		    (mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) &&
		    (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) {
			/* Var MTRR contains UC entry below 1M? Skip it: */
			pr_warn(BIOS_BUG_MSG, i);
			if (base + size <= (1<<(20-PAGE_SHIFT)))
				continue;
			size -= (1<<(20-PAGE_SHIFT)) - base;
			base = 1<<(20-PAGE_SHIFT);
		}
		subtract_range(range, RANGE_NUM, base, base + size);
	}
	if (extra_remove_size)
		subtract_range(range, RANGE_NUM, extra_remove_base,
				 extra_remove_base + extra_remove_size);

	Dprintk("After UC checking\n");
	for (i = 0; i < RANGE_NUM; i++) {
		if (!range[i].end)
			continue;

		Dprintk("MTRR MAP PFN: %016llx - %016llx\n",
			 range[i].start, range[i].end);
	}

	/* sort the ranges */
	nr_range = clean_sort_range(range, RANGE_NUM);

	Dprintk("After sorting\n");
	for (i = 0; i < nr_range; i++)
		Dprintk("MTRR MAP PFN: %016llx - %016llx\n",
			range[i].start, range[i].end);

	return nr_range;
}

#ifdef CONFIG_MTRR_SANITIZER

static unsigned long __init sum_ranges(struct range *range, int nr_range)
{
	unsigned long sum = 0;
	int i;

	for (i = 0; i < nr_range; i++)
		sum += range[i].end - range[i].start;

	return sum;
}

static int enable_mtrr_cleanup __initdata =
	CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT;

static int __init disable_mtrr_cleanup_setup(char *str)
{
	enable_mtrr_cleanup = 0;
	return 0;
}
early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup);

static int __init enable_mtrr_cleanup_setup(char *str)
{
	enable_mtrr_cleanup = 1;
	return 0;
}
early_param("enable_mtrr_cleanup", enable_mtrr_cleanup_setup);

static void __init
set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
	     unsigned char type)
{
	u32 base_lo, base_hi, mask_lo, mask_hi;
	u64 base, mask;

	if (!sizek) {
		fill_mtrr_var_range(reg, 0, 0, 0, 0);
		return;
	}

	mask = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
	mask &= ~((((u64)sizek) << 10) - 1);

	base = ((u64)basek) << 10;

	base |= type;
	mask |= 0x800;

	base_lo = base & ((1ULL<<32) - 1);
	base_hi = base >> 32;

	mask_lo = mask & ((1ULL<<32) - 1);
	mask_hi = mask >> 32;

	fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi);
}

static void __init
save_var_mtrr(unsigned int reg