x86: separate mtrr cleanup/mtrr_e820 trim to separate file

Impact: cleanup

mtrr main.c is too big, seperate mtrr cleanup and mtrr e820 trim
code to another file.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49B87C7B.80809@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1089 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c
new file mode 100644
index 000000000000..58b58bbf7eb3
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/cleanup.c
@@ -0,0 +1,1089 @@
+/*  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/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/mutex.h>
+#include <linux/sort.h>
+
+#include <asm/e820.h>
+#include <asm/mtrr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/msr.h>
+#include <asm/kvm_para.h>
+#include "mtrr.h"
+
+/* should be related to MTRR_VAR_RANGES nums */
+#define RANGE_NUM 256
+
+struct res_range {
+	unsigned long start;
+	unsigned long end;
+};
+
+static int __init
+add_range(struct res_range *range, int nr_range, unsigned long start,
+			      unsigned long end)
+{
+	/* out of slots */
+	if (nr_range >= RANGE_NUM)
+		return nr_range;
+
+	range[nr_range].start = start;
+	range[nr_range].end = end;
+
+	nr_range++;
+
+	return nr_range;
+}
+
+static int __init
+add_range_with_merge(struct res_range *range, int nr_range, unsigned long start,
+			      unsigned long end)
+{
+	int i;
+
+	/* try to merge it with old one */
+	for (i = 0; i < nr_range; i++) {
+		unsigned long final_start, final_end;
+		unsigned long common_start, common_end;
+
+		if (!range[i].end)
+			continue;
+
+		common_start = max(range[i].start, start);
+		common_end = min(range[i].end, end);
+		if (common_start > common_end + 1)
+			continue;
+
+		final_start = min(range[i].start, start);
+		final_end = max(range[i].end, end);
+
+		range[i].start = final_start;
+		range[i].end =  final_end;
+		return nr_range;
+	}
+
+	/* need to add that */
+	return add_range(range, nr_range, start, end);
+}
+
+static void __init
+subtract_range(struct res_range *range, unsigned long start, unsigned long end)
+{
+	int i, j;
+
+	for (j = 0; j < RANGE_NUM; j++) {
+		if (!range[j].end)
+			continue;
+
+		if (start <= range[j].start && end >= range[j].end) {
+			range[j].start = 0;
+			range[j].end = 0;
+			continue;
+		}
+
+		if (start <= range[j].start && end < range[j].end &&
+		    range[j].start < end + 1) {
+			range[j].start = end + 1;
+			continue;
+		}
+
+
+		if (start > range[j].start && end >= range[j].end &&
+		    range[j].end > start - 1) {
+			range[j].end = start - 1;
+			continue;
+		}
+
+		if (start > range[j].start && end < range[j].end) {
+			/* find the new spare */
+			for (i = 0; i < RANGE_NUM; i++) {
+				if (range[i].end == 0)
+					break;
+			}
+			if (i < RANGE_NUM) {
+				range[i].end = range[j].end;
+				range[i].start = end + 1;
+			} else {
+				printk(KERN_ERR "run of slot in ranges\n");
+			}
+			range[j].end = start - 1;
+			continue;
+		}
+	}
+}
+
+static int __init cmp_range(const void *x1, const void *x2)
+{
+	const struct res_range *r1 = x1;
+	const struct res_range *r2 = x2;
+	long start1, start2;
+
+	start1 = r1->start;
+	start2 = r2->start;
+
+	return start1 - start2;
+}
+
+struct var_mtrr_range_state {
+	unsigned long base_pfn;
+	unsigned long size_pfn;
+	mtrr_type type;
+};
+
+static struct var_mtrr_range_state __initdata range_state[RANGE_NUM];
+static int __initdata debug_print;
+
+static int __init
+x86_get_mtrr_mem_range(struct res_range *range, int nr_range,
+		       unsigned long extra_remove_base,
+		       unsigned long extra_remove_size)
+{
+	unsigned long i, base, size;
+	mtrr_type type;
+
+	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, nr_range, base,
+						base + size - 1);
+	}
+	if (debug_print) {
+		printk(KERN_DEBUG "After WB checking\n");
+		for (i = 0; i < nr_range; i++)
+			printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+				 range[i].start, range[i].end + 1);
+	}
+
+	/* 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;
+		subtract_range(range, base, base + size - 1);
+	}
+	if (extra_remove_size)
+		subtract_range(range, extra_remove_base,
+				 extra_remove_base + extra_remove_size  - 1);
+
+	/* get new range num */
+	nr_range = 0;
+	for (i = 0; i < RANGE_NUM; i++) {
+		if (!range[i].end)
+			continue;
+		nr_range++;
+	}
+	if  (debug_print) {
+		printk(KERN_DEBUG "After UC checking\n");
+		for (i = 0; i < nr_range; i++)
+			printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+				 range[i].start, range[i].end + 1);
+	}
+
+	/* sort the ranges */
+	sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
+	if  (debug_print) {
+		printk(KERN_DEBUG "After sorting\n");
+		for (i = 0; i < nr_range; i++)
+			printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+				 range[i].start, range[i].end + 1);
+	}
+
+	/* clear those is not used */
+	for (i = nr_range; i < RANGE_NUM; i++)
+		memset(&range[i], 0, sizeof(range[i]));
+
+	return nr_range;
+}
+
+static struct res_range __initdata range[RANGE_NUM];
+static int __initdata nr_range;
+
+#ifdef CONFIG_MTRR_SANITIZER
+
+static unsigned long __init sum_ranges(struct res_range *range, int nr_range)
+{
+	unsigned long sum;
+	int i;
+
+	sum = 0;
+	for (i = 0; i < nr_range; i++)
+		sum += range[i].end + 1 - 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 int __init mtrr_cleanup_debug_setup(char *str)
+{
+	debug_print = 1;
+	return 0;
+}
+early_param("mtrr_cleanup_debug", mtrr_cleanup_debug_setup);
+
+struct var_mtrr_state {
+	unsigned long	range_startk;
+	unsigned long	range_sizek;
+	unsigned long	chunk_sizek;
+	unsigned long	gran_sizek;
+	unsigned int	reg;
+};
+
+static void __init
+set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
+		unsigned char type, unsigned int address_bits)
+{
+	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 << address_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, unsigned long basek, unsigned long sizek,
+		unsigned char type)
+{
+	range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10);
+	range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10);
+	range_state[reg].type = type;
+}
+
+static void __init
+set_var_mtrr_all(unsigned int address_bits)
+{
+	unsigned long basek, sizek;
+	unsigned char type;
+	unsigned int reg;
+
+	for (reg = 0; reg < num_var_ranges; reg++) {
+		basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10);
+		sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10);
+		type = range_state[reg].type;
+
+		set_var_mtrr(reg, basek, sizek, type, address_bits);
+	}
+}
+
+static unsigned long to_size_factor(unsigned long sizek, char *factorp)
+{
+	char factor;
+	unsigned long base = sizek;
+
+	if (base & ((1<<10) - 1)) {
+		/* not MB alignment */
+		factor = 'K';
+	} else if (base & ((1<<20) - 1)) {
+		factor = 'M';
+		base >>= 10;
+	} else {
+		factor = 'G';
+		base >>= 20;
+	}
+
+	*factorp = factor;
+
+	return base;
+}
+
+static unsigned int __init
+range_to_mtrr(unsigned int reg, unsigned long range_startk,
+	      unsigned long range_sizek, unsigned char type)
+{
+	if (!range_sizek || (reg >= num_var_ranges))
+		return reg;
+
+	while (range_sizek) {
+		unsigned long max_align, align;
+		unsigned long sizek;
+
+		/* Compute the maximum size I can make a range */
+		if (range_startk)
+			max_align = ffs(range_startk) - 1;
+		else
+			max_align = 32;
+		align = fls(range_sizek) - 1;
+		if (align > max_align)
+			align = max_align;
+
+		sizek = 1 << align;
+		if (debug_print) {
+			char start_factor = 'K', size_factor = 'K';
+			unsigned long start_base, size_base;
+
+			start_base = to_size_factor(range_startk,
+							 &start_factor),
+			size_base = to_size_factor(sizek, &size_factor),
+
+			printk(KERN_DEBUG "Setting variable MTRR %d, "
+				"base: %ld%cB, range: %ld%cB, type %s\n",
+				reg, start_base, start_factor,
+				size_base, size_factor,
+				(type == MTRR_TYPE_UNCACHABLE) ? "UC" :
+				   ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")
+				);
+		}
+		save_var_mtrr(reg++, range_startk, sizek, type);
+		range_startk += sizek;
+		range_sizek -= sizek;
+		if (reg >= num_var_ranges)
+			break;
+	}
+	return reg;
+}
+
+static unsigned __init
+range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek,
+			unsigned long sizek)
+{
+	unsigned long hole_basek, hole_sizek;
+	unsigned long second_basek, second_sizek;
+	unsigned long range0_basek, range0_sizek;
+	unsigned long range_basek, range_sizek;
+	unsigned long chunk_sizek;
+	unsigned long gran_sizek;
+
+	hole_basek = 0;
+	hole_sizek = 0;
+	second_basek = 0;
+	second_sizek = 0;
+	chunk_sizek = state->chunk_sizek;
+	gran_sizek = state->gran_sizek;
+
+	/* align with gran size, prevent small block used up MTRRs */
+	range_basek = ALIGN(state->range_startk, gran_sizek);
+	if ((range_basek > basek) && basek)
+		return second_sizek;
+	state->range_sizek -= (range_basek - state->range_startk);
+	range_sizek = ALIGN(state->range_sizek, gran_sizek);
+
+	while (range_sizek > state->range_sizek) {
+		range_sizek -= gran_sizek;
+		if (!range_sizek)
+			return 0;
+	}
+	state->range_sizek = range_sizek;
+
+	/* try to append some small hole */
+	range0_basek = state->range_startk;
+	range0_sizek = ALIGN(state->range_sizek, chunk_sizek);
+
+	/* no increase */
+	if (range0_sizek == state->range_sizek) {
+		if (debug_print)
+			printk(KERN_DEBUG "rangeX: %016lx - %016lx\n",
+				range0_basek<<10,
+				(range0_basek + state->range_sizek)<<10);
+		state->reg = range_to_mtrr(state->reg, range0_basek,
+				state->range_sizek, MTRR_TYPE_WRBACK);
+		return 0;
+	}
+
+	/* only cut back, when it is not the last */
+	if (sizek) {
+		while (range0_basek + range0_sizek > (basek + sizek)) {
+			if (range0_sizek >= chunk_sizek)
+				range0_sizek -= chunk_sizek;
+			else
+				range0_sizek = 0;
+
+			if (!range0_sizek)
+				break;
+		}
+	}
+
+second_try:
+	range_basek = range0_basek + range0_sizek;
+
+	/* one hole in the middle */
+	if (range_basek > basek && range_basek <= (basek + sizek))
+		second_sizek = range_basek - basek;
+
+	if (range0_sizek > state->range_sizek) {
+
+		/* one hole in middle or at end */
+		hole_sizek = range0_sizek - state->range_sizek - second_sizek;
+
+		/* hole size should be less than half of range0 size */
+		if (hole_sizek >= (range0_sizek >> 1) &&
+		    range0_sizek >= chunk_sizek) {
+			range0_sizek -= chunk_sizek;
+			second_sizek = 0;
+			hole_sizek = 0;
+
+			goto second_try;
+		}
+	}
+
+	if (range0_sizek) {
+		if (debug_print)
+			printk(KERN_DEBUG "range0: %016lx - %016lx\n",
+				range0_basek<<10,
+				(range0_basek + range0_sizek)<<10);
+		state->reg = range_to_mtrr(state->reg, range0_basek,
+				range0_sizek, MTRR_TYPE_WRBACK);
+	}
+
+	if (range0_sizek < state->range_sizek) {
+		/* need to handle left over */
+		range_sizek = state->range_sizek - range0_sizek;
+
+		if (debug_print)
+			printk(KERN_DEBUG "range: %016lx - %016lx\n",
+				 range_basek<<10,
+				 (range_basek + range_sizek)<<10);
+		state->reg = range_to_mtrr(state->reg, range_basek,
+				 range_sizek, MTRR_TYPE_WRBACK);
+	}
+
+	if (hole_sizek) {
+		hole_basek = range_basek - hole_sizek - second_sizek;
+		if (debug_print)
+			printk(KERN_DEBUG "hole: %016lx - %016lx\n",
+				 hole_basek<<10,
+				 (hole_basek + hole_sizek)<<10);
+		state->reg = range_to_mtrr(state->reg, hole_basek,
+				 hole_sizek, MTRR_TYPE_UNCACHABLE);
+	}
+
+	return second_sizek;
+}
+
+static void __init
+set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn,
+		   unsigned long size_pfn)
+{
+	unsigned long basek, sizek;
+	unsigned long second_sizek = 0;
+
+	if (state->reg >= num_var_ranges)
+		return;
+
+	basek = base_pfn << (PAGE_SHIFT - 10);
+	sizek = size_pfn << (PAGE_SHIFT - 10);
+
+	/* See if I can merge with the last range */
+	if ((basek <= 1024) ||
+	    (state->range_startk + state->range_sizek == basek)) {
+		unsigned long endk = basek + sizek;
+		state->range_sizek = endk - state->range_startk;
+		return;
+	}
+	/* Write the range mtrrs */
+	if (state->range_sizek != 0)
+		second_sizek = range_to_mtrr_with_hole(state, basek, sizek);
+
+	/* Allocate an msr */
+	state->range_startk = basek + second_sizek;
+	state->range_sizek  = sizek - second_sizek;
+}
+
+/* mininum size of mtrr block that can take hole */
+static u64 mtrr_chunk_size __initdata = (256ULL<<20);
+
+static int __init parse_mtrr_chunk_size_opt(char *p)
+{
+	if (!p)
+		return -EINVAL;
+	mtrr_chunk_size = memparse(p, &p);
+	return 0;
+}
+early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt);
+
+/* granity of mtrr of block */
+static u64 mtrr_gran_size __initdata;
+
+static int __init parse_mtrr_gran_size_opt(char *p)
+{
+	if (!p)
+		return -EINVAL;
+	mtrr_gran_size = memparse(p, &p);
+	return 0;
+}
+early_param("mtrr_gran_size", parse_mtrr_gran_size_opt);
+
+static int nr_mtrr_spare_reg __initdata =
+				 CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT;
+
+static int __init parse_mtrr_spare_reg(char *arg)
+{
+	if (arg)
+		nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0);
+	return 0;
+}
+
+early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg);
+
+static int __init
+x86_setup_var_mtrrs(struct res_range *range, int nr_range,
+		    u64 chunk_size, u64 gran_size)
+{
+	struct var_mtrr_state var_state;
+	int i;
+	int num_reg;
+
+	var_state.range_startk	= 0;
+	var_state.range_sizek	= 0;
+	var_state.reg		= 0;
+	var_state.chunk_sizek	= chunk_size >> 10;
+	var_state.gran_sizek	= gran_size >> 10;
+
+	memset(range_state, 0, sizeof(range_state));
+
+	/* Write the range etc */
+	for (i = 0; i < nr_range; i++)
+		set_var_mtrr_range(&var_state, range[i].start,
+				   range[i].end - range[i].start + 1);
+
+	/* Write the last range */
+	if (var_state.range_sizek != 0)
+		range_to_mtrr_with_hole(&var_state, 0, 0);
+
+	num_reg = var_state.reg;
+	/* Clear out the extra MTRR's */
+	while (var_state.reg < num_var_ranges) {
+		save_var_mtrr(var_state.reg, 0, 0, 0);
+		var_state.reg++;
+	}
+
+	return num_reg;
+}
+
+struct mtrr_cleanup_result {
+	unsigned long gran_sizek;
+	unsigned long chunk_sizek;
+	unsigned long lose_cover_sizek;
+	unsigned int num_reg;
+	int bad;
+};
+
+/*
+ * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G
+ * chunk size: gran_size, ..., 2G
+ * so we need (1+16)*8
+ */
+#define NUM_RESULT	136
+#define PSHIFT		(PAGE_SHIFT - 10)
+
+static struct mtrr_cleanup_result __initdata result[NUM_RESULT];
+static unsigned long __initdata min_loss_pfn[RANGE_NUM];
+
+static void __init print_out_mtrr_range_state(void)
+{
+	int i;
+	char start_factor = 'K', size_factor = 'K';
+	unsigned long start_base, size_base;
+	mtrr_type type;
+
+	for (i = 0; i < num_var_ranges; i++) {
+
+		size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10);
+		if (!size_base)
+			continue;
+
+		size_base = to_size_factor(size_base, &size_factor),
+		start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10);
+		start_base = to_size_factor(start_base, &start_factor),
+		type = range_state[i].type;
+
+		printk(KERN_DEBUG "reg %d, base: %ld%cB, range: %ld%cB, type %s\n",
+			i, start_base, start_factor,
+			size_base, size_factor,
+			(type == MTRR_TYPE_UNCACHABLE) ? "UC" :
+			    ((type == MTRR_TYPE_WRPROT) ? "WP" :
+			     ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other"))
+			);
+	}
+}
+
+static int __init mtrr_need_cleanup(void)
+{
+	int i;
+	mtrr_type type;
+	unsigned long size;
+	/* extra one for all 0 */
+	int num[MTRR_NUM_TYPES + 1];
+
+	/* check entries number */
+	memset(num, 0, sizeof(num));
+	for (i = 0; i < num_var_ranges; i++) {
+		type = range_state[i].type;
+		size = range_state[i].size_pfn;
+		if (type >= MTRR_NUM_TYPES)
+			continue;
+		if (!size)
+			type = MTRR_NUM_TYPES;
+		if (type == MTRR_TYPE_WRPROT)
+			type = MTRR_TYPE_UNCACHABLE;
+		num[type]++;
+	}
+
+	/* check if we got UC entries */
+	if (!num[MTRR_TYPE_UNCACHABLE])
+		return 0;
+
+	/* check if we only had WB and UC */
+	if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
+		num_var_ranges - num[MTRR_NUM_TYPES])
+		return 0;
+
+	return 1;
+}
+
+static unsigned long __initdata range_sums;
+static void __init mtrr_calc_range_state(u64 chunk_size, u64 gran_size,
+					 unsigned long extra_remove_base,
+					 unsigned long extra_remove_size,
+					 int i)
+{
+	int num_reg;
+	static struct res_range range_new[RANGE_NUM];
+	static int nr_range_new;
+	unsigned long range_sums_new;
+
+	/* convert ranges to var ranges state */
+	num_reg = x86_setup_var_mtrrs(range, nr_range,
+						chunk_size, gran_size);
+
+	/* we got new setting in range_state, check it */
+	memset(range_new, 0, sizeof(range_new));
+	nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
+				extra_remove_base, extra_remove_size);
+	range_sums_new = sum_ranges(range_new, nr_range_new);
+
+	result[i].chunk_sizek = chunk_size >> 10;
+	result[i].gran_sizek = gran_size >> 10;
+	result[i].num_reg = num_reg;
+	if (range_sums < range_sums_new) {
+		result[i].lose_cover_sizek =
+			(range_sums_new - range_sums) << PSHIFT;
+		result[i].bad = 1;
+	} else
+		result[i].lose_cover_sizek =
+			(range_sums - range_sums_new) << PSHIFT;
+
+	/* double check it */
+	if (!result[i].bad && !result[i].lose_cover_sizek) {
+		if (nr_range_new != nr_range ||
+			memcmp(range, range_new, sizeof(range)))
+				result[i].bad = 1;
+	}
+
+	if (!result[i].bad && (range_sums - range_sums_new <
+				min_loss_pfn[num_reg])) {
+		min_loss_pfn[num_reg] =
+			range_sums - range_sums_new;
+	}
+}
+
+static void __init mtrr_print_out_one_result(int i)
+{
+	char gran_factor, chunk_factor, lose_factor;
+	unsigned long gran_base, chunk_base, lose_base;
+
+	gran_base = to_size_factor(result[i].gran_sizek, &gran_factor),
+	chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor),
+	lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor),
+	printk(KERN_INFO "%sgran_size: %ld%c \tchunk_size: %ld%c \t",
+			result[i].bad ? "*BAD*" : " ",
+			gran_base, gran_factor, chunk_base, chunk_factor);
+	printk(KERN_CONT "num_reg: %d  \tlose cover RAM: %s%ld%c\n",
+			result[i].num_reg, result[i].bad ? "-" : "",
+			lose_base, lose_factor);
+}
+
+static int __init mtrr_search_optimal_index(void)
+{
+	int i;
+	int num_reg_good;
+	int index_good;
+
+	if (nr_mtrr_spare_reg >= num_var_ranges)
+		nr_mtrr_spare_reg = num_var_ranges - 1;
+	num_reg_good = -1;
+	for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) {
+		if (!min_loss_pfn[i])
+			num_reg_good = i;
+	}
+
+	index_good = -1;
+	if (num_reg_good != -1) {
+		for (i = 0; i < NUM_RESULT; i++) {
+			if (!result[i].bad &&
+			    result[i].num_reg == num_reg_good &&
+			    !result[i].lose_cover_sizek) {
+				index_good = i;
+				break;
+			}
+		}
+	}
+
+	return index_good;
+}
+
+
+int __init mtrr_cleanup(unsigned address_bits)
+{
+	unsigned long extra_remove_base, extra_remove_size;
+	unsigned long base, size, def, dummy;
+	mtrr_type type;
+	u64 chunk_size, gran_size;
+	int index_good;
+	int i;
+
+	if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1)
+		return 0;
+	rdmsr(MTRRdefType_MSR, def, dummy);
+	def &= 0xff;
+	if (def != MTRR_TYPE_UNCACHABLE)
+		return 0;
+
+	/* get it and store it aside */
+	memset(range_state, 0, sizeof(range_state));
+	for (i = 0; i < num_var_ranges; i++) {
+		mtrr_if->get(i, &base, &size, &type);
+		range_state[i].base_pfn = base;
+		range_state[i].size_pfn = size;
+		range_state[i].type = type;
+	}
+
+	/* check if we need handle it and can handle it */
+	if (!mtrr_need_cleanup())
+		return 0;
+
+	/* print original var MTRRs at first, for debugging: */
+	printk(KERN_DEBUG "original variable MTRRs\n");
+	print_out_mtrr_range_state();
+
+	memset(range, 0, sizeof(range));
+	extra_remove_size = 0;
+	extra_remove_base = 1 << (32 - PAGE_SHIFT);
+	if (mtrr_tom2)
+		extra_remove_size =
+			(mtrr_tom2 >> PAGE_SHIFT) - extra_remove_base;
+	nr_range = x86_get_mtrr_mem_range(range, 0, extra_remove_base,
+					  extra_remove_size);
+	/*
+	 * [0, 1M) should always be coverred by var mtrr with WB
+	 * and fixed mtrrs should take effective before var mtrr for it
+	 */
+	nr_range = add_range_with_merge(range, nr_range, 0,
+					(1ULL<<(20 - PAGE_SHIFT)) - 1);
+	/* sort the ranges */
+	sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
+
+	range_sums = sum_ranges(range, nr_range);
+	printk(KERN_INFO "total RAM coverred: %ldM\n",
+	       range_sums >> (20 - PAGE_SHIFT));
+
+	if (mtrr_chunk_size && mtrr_gran_size) {
+		i = 0;
+		mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size,
+				      extra_remove_base, extra_remove_size, i);
+
+		mtrr_print_out_one_result(i);
+
+		if (!result[i].bad) {
+			set_var_mtrr_all(address_bits);
+			printk(KERN_DEBUG "New variable MTRRs\n");
+			print_out_mtrr_range_state();
+			return 1;
+		}
+		printk(KERN_INFO "invalid mtrr_gran_size or mtrr_chunk_size, "
+		       "will find optimal one\n");
+	}
+
+	i = 0;
+	memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn));
+	memset(result, 0, sizeof(result));
+	for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) {
+
+		for (chunk_size = gran_size; chunk_size < (1ULL<<32);
+		     chunk_size <<= 1) {
+
+			if (i >= NUM_RESULT)
+				continue;
+
+			mtrr_calc_range_state(chunk_size, gran_size,
+				      extra_remove_base, extra_remove_size, i);
+			if (debug_print) {
+				mtrr_print_out_one_result(i);
+				printk(KERN_INFO "\n");
+			}
+
+			i++;
+		}
+	}
+
+	/* try to find the optimal index */
+	index_good = mtrr_search_optimal_index();
+
+	if (index_good != -1) {
+		printk(KERN_INFO "Found optimal setting for mtrr clean up\n");
+		i = index_good;
+		mtrr_print_out_one_result(i);
+
+		/* convert ranges to var ranges state */
+		chunk_size = result[i].chunk_sizek;
+		chunk_size <<= 10;
+		gran_size = result[i].gran_sizek;
+		gran_size <<= 10;
+		x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
+		set_var_mtrr_all(address_bits);
+		printk(KERN_DEBUG "New variable MTRRs\n");
+		print_out_mtrr_range_state();
+		return 1;
+	} else {
+		/* print out all */
+		for (i = 0; i < NUM_RESULT; i++)
+			mtrr_print_out_one_result(i);
+	}
+
+	printk(KERN_INFO "mtrr_cleanup: can not find optimal value\n");
+	printk(KERN_INFO "please specify mtrr_gran_size/mtrr_chunk_size\n");
+
+	return 0;
+}
+#else
+int __init mtrr_cleanup(unsigned address_bits)
+{
+	return 0;
+}
+#endif
+
+static int disable_mtrr_trim;
+
+static int __init disable_mtrr_trim_setup(char *str)
+{
+	disable_mtrr_trim = 1;
+	return 0;
+}
+early_param("disable_mtrr_trim", disable_mtrr_trim_setup);
+
+/*
+ * Newer AMD K8s and later CPUs have a special magic MSR way to force WB
+ * for memory >4GB. Check for that here.
+ * Note this won't check if the MTRRs < 4GB where the magic bit doesn't
+ * apply to are wrong, but so far we don't know of any such case in the wild.
+ */
+#define Tom2Enabled (1U << 21)
+#define Tom2ForceMemTypeWB (1U << 22)
+
+int __init amd_special_default_mtrr(void)
+{
+	u32 l, h;
+
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+		return 0;
+	if (boot_cpu_data.x86 < 0xf || boot_cpu_data.x86 > 0x11)
+		return 0;
+	/* In case some hypervisor doesn't pass SYSCFG through */
+	if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0)
+		return 0;
+	/*
+	 * Memory between 4GB and top of mem is forced WB by this magic bit.
+	 * Reserved before K8RevF, but should be zero there.
+	 */
+	if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) ==
+		 (Tom2Enabled | Tom2ForceMemTypeWB))
+		return 1;
+	return 0;
+}
+
+static u64 __init real_trim_memory(unsigned long start_pfn,
+				   unsigned long limit_pfn)
+{
+	u64 trim_start, trim_size;
+	trim_start = start_pfn;
+	trim_start <<= PAGE_SHIFT;
+	trim_size = limit_pfn;
+	trim_size <<= PAGE_SHIFT;
+	trim_size -= trim_start;
+
+	return e820_update_range(trim_start, trim_size, E820_RAM,
+				E820_RESERVED);
+}
+/**
+ * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs
+ * @end_pfn: ending page frame number
+ *
+ * Some buggy BIOSes don't setup the MTRRs properly for systems with certain
+ * memory configurations.  This routine checks that the highest MTRR matches
+ * the end of memory, to make sure the MTRRs having a write back type cover
+ * all of the memory the kernel is intending to use. If not, it'll trim any
+ * memory off the end by adjusting end_pfn, removing it from the kernel's
+ * allocation pools, warning the user with an obnoxious message.
+ */
+int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
+{
+	unsigned long i, base, size, highest_pfn = 0, def, dummy;
+	mtrr_type type;
+	u64 total_trim_size;
+
+	/* extra one for all 0 */
+	int num[MTRR_NUM_TYPES + 1];
+	/*
+	 * Make sure we only trim uncachable memory on machines that
+	 * support the Intel MTRR architecture:
+	 */
+	if (!is_cpu(INTEL) || disable_mtrr_trim)
+		return 0;
+	rdmsr(MTRRdefType_MSR, def, dummy);
+	def &= 0xff;
+	if (def != MTRR_TYPE_UNCACHABLE)
+		return 0;
+
+	/* get it and store it aside */
+	memset(range_state, 0, sizeof(range_state));
+	for (i = 0; i < num_var_ranges; i++) {
+		mtrr_if->get(i, &base, &size, &type);
+		range_state[i].base_pfn = base;
+		range_state[i].size_pfn = size;
+		range_state[i].type = type;
+	}
+
+	/* Find highest cached pfn */
+	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;
+		if (highest_pfn < base + size)
+			highest_pfn = base + size;
+	}
+
+	/* kvm/qemu doesn't have mtrr set right, don't trim them all */
+	if (!highest_pfn) {
+		printk(KERN_INFO "CPU MTRRs all blank - virtualized system.\n");
+		return 0;
+	}
+
+	/* check entries number */
+	memset(num, 0, sizeof(num));
+	for (i = 0; i < num_var_ranges; i++) {
+		type = range_state[i].type;
+		if (type >= MTRR_NUM_TYPES)
+			continue;
+		size = range_state[i].size_pfn;
+		if (!size)
+			type = MTRR_NUM_TYPES;
+		num[type]++;
+	}
+
+	/* no entry for WB? */
+	if (!num[MTRR_TYPE_WRBACK])
+		return 0;
+
+	/* check if we only had WB and UC */
+	if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] !=
+		num_var_ranges - num[MTRR_NUM_TYPES])
+		return 0;
+
+	memset(range, 0, sizeof(range));
+	nr_range = 0;
+	if (mtrr_tom2) {
+		range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT));
+		range[nr_range].end = (mtrr_tom2 >> PAGE_SHIFT) - 1;
+		if (highest_pfn < range[nr_range].end + 1)
+			highest_pfn = range[nr_range].end + 1;
+		nr_range++;
+	}
+	nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0);
+
+	total_trim_size = 0;
+	/* check the head */
+	if (range[0].start)
+		total_trim_size += real_trim_memory(0, range[0].start);
+	/* check the holes */
+	for (i = 0; i < nr_range - 1; i++) {
+		if (range[i].end + 1 < range[i+1].start)
+			total_trim_size += real_trim_memory(range[i].end + 1,
+							    range[i+1].start);
+	}
+	/* check the top */
+	i = nr_range - 1;
+	if (range[i].end + 1 < end_pfn)
+		total_trim_size += real_trim_memory(range[i].end + 1,
+							 end_pfn);
+
+	if (total_trim_size) {
+		printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
+			" all of memory, losing %lluMB of RAM.\n",
+			total_trim_size >> 20);
+
+		if (!changed_by_mtrr_cleanup)
+			WARN_ON(1);
+
+		printk(KERN_INFO "update e820 for mtrr\n");
+		update_e820();
+
+		return 1;
+	}
+
+	return 0;
+}
+