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linux/arch/x86/kernel/cpu/mtrr/cleanup.c
Yinghai Lu f0348c438c x86: MTRR workaround for system with stange var MTRRs 
Impact: don't trim e820 according to wrong mtrr

Ozan reports that his server emits strange warning.
it turns out the BIOS sets the MTRRs incorrectly.

Ignore those strange ranges, and don't trim e820,
just emit one warning about BIOS

Reported-by: Ozan Çağlayan <ozan@pardus.org.tr>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <49BEE1E7.7020706@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-17 10:47:47 +01:00

1100 lines
27 KiB
C
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/* 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;
if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed &&
(mtrr_state.enabled & 1)) {
/* Var MTRR contains UC entry below 1M? Skip it: */
printk(KERN_WARNING "WARNING: BIOS bug: VAR MTRR %d "
"contains strange UC entry under 1M, check "
"with your system vendor!\n", i);
if (base + size <= (1<<(20-PAGE_SHIFT)))
continue;
size -= (1<<(20-PAGE_SHIFT)) - base;
base = 1<<(20-PAGE_SHIFT);
}
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;
}
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