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|
// SPDX-License-Identifier: GPL-2.0-only
/*
* This only handles 32bit MTRR on 32bit hosts. This is strictly wrong
* because MTRRs can span up to 40 bits (36bits on most modern x86)
*/
#include <linux/export.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/cc_platform.h>
#include <asm/processor-flags.h>
#include <asm/cacheinfo.h>
#include <asm/cpufeature.h>
#include <asm/hypervisor.h>
#include <asm/mshyperv.h>
#include <asm/tlbflush.h>
#include <asm/mtrr.h>
#include <asm/msr.h>
#include <asm/memtype.h>
#include "mtrr.h"
struct fixed_range_block {
int base_msr; /* start address of an MTRR block */
int ranges; /* number of MTRRs in this block */
};
static struct fixed_range_block fixed_range_blocks[] = {
{ MSR_MTRRfix64K_00000, 1 }, /* one 64k MTRR */
{ MSR_MTRRfix16K_80000, 2 }, /* two 16k MTRRs */
{ MSR_MTRRfix4K_C0000, 8 }, /* eight 4k MTRRs */
{}
};
struct cache_map {
u64 start;
u64 end;
u64 flags;
u64 type:8;
u64 fixed:1;
};
bool mtrr_debug;
static int __init mtrr_param_setup(char *str)
{
int rc = 0;
if (!str)
return -EINVAL;
if (!strcmp(str, "debug"))
mtrr_debug = true;
else
rc = -EINVAL;
return rc;
}
early_param("mtrr", mtrr_param_setup);
/*
* CACHE_MAP_MAX is the maximum number of memory ranges in cache_map, where
* no 2 adjacent ranges have the same cache mode (those would be merged).
* The number is based on the worst case:
* - no two adjacent fixed MTRRs share the same cache mode
* - one variable MTRR is spanning a huge area with mode WB
* - 255 variable MTRRs with mode UC all overlap with the WB MTRR, creating 2
* additional ranges each (result like "ababababa...aba" with a = WB, b = UC),
* accounting for MTRR_MAX_VAR_RANGES * 2 - 1 range entries
* - a TOP_MEM2 area (even with overlapping an UC MTRR can't add 2 range entries
* to the possible maximum, as it always starts at 4GB, thus it can't be in
* the middle of that MTRR, unless that MTRR starts at 0, which would remove
* the initial "a" from the "abababa" pattern above)
* The map won't contain ranges with no matching MTRR (those fall back to the
* default cache mode).
*/
#define CACHE_MAP_MAX (MTRR_NUM_FIXED_RANGES + MTRR_MAX_VAR_RANGES * 2)
static struct cache_map init_cache_map[CACHE_MAP_MAX] __initdata;
static struct cache_map *cache_map __refdata = init_cache_map;
static unsigned int cache_map_size = CACHE_MAP_MAX;
static unsigned int cache_map_n;
static unsigned int cache_map_fixed;
static unsigned long smp_changes_mask;
static int mtrr_state_set;
u64 mtrr_tom2;
struct mtrr_state_type mtrr_state;
EXPORT_SYMBOL_GPL(mtrr_state);
/* Reserved bits in the high portion of the MTRRphysBaseN MSR. */
u32 phys_hi_rsvd;
/*
* BIOS is expected to clear MtrrFixDramModEn bit, see for example
* "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
* Opteron Processors" (26094 Rev. 3.30 February 2006), section
* "13.2.1.2 SYSCFG Register": "The MtrrFixDramModEn bit should be set
* to 1 during BIOS initialization of the fixed MTRRs, then cleared to
* 0 for operation."
*/
static inline void k8_check_syscfg_dram_mod_en(void)
{
u32 lo, hi;
if (!((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
(boot_cpu_data.x86 >= 0x0f)))
return;
if (cpu_feature_enabled(X86_FEATURE_SEV_SNP))
return;
rdmsr(MSR_AMD64_SYSCFG, lo, hi);
if (lo & K8_MTRRFIXRANGE_DRAM_MODIFY) {
pr_err(FW_WARN "MTRR: CPU %u: SYSCFG[MtrrFixDramModEn]"
" not cleared by BIOS, clearing this bit\n",
smp_processor_id());
lo &= ~K8_MTRRFIXRANGE_DRAM_MODIFY;
mtrr_wrmsr(MSR_AMD64_SYSCFG, lo, hi);
}
}
/* Get the size of contiguous MTRR range */
static u64 get_mtrr_size(u64 mask)
{
u64 size;
mask |= (u64)phys_hi_rsvd << 32;
size = -mask;
return size;
}
static u8 get_var_mtrr_state(unsigned int reg, u64 *start, u64 *size)
{
struct mtrr_var_range *mtrr = mtrr_state.var_ranges + reg;
if (!(mtrr->mask_lo & MTRR_PHYSMASK_V))
return MTRR_TYPE_INVALID;
*start = (((u64)mtrr->base_hi) << 32) + (mtrr->base_lo & PAGE_MASK);
*size = get_mtrr_size((((u64)mtrr->mask_hi) << 32) +
(mtrr->mask_lo & PAGE_MASK));
return mtrr->base_lo & MTRR_PHYSBASE_TYPE;
}
static u8 get_effective_type(u8 type1, u8 type2)
{
if (type1 == MTRR_TYPE_UNCACHABLE || type2 == MTRR_TYPE_UNCACHABLE)
return MTRR_TYPE_UNCACHABLE;
if ((type1 == MTRR_TYPE_WRBACK && type2 == MTRR_TYPE_WRTHROUGH) ||
(type1 == MTRR_TYPE_WRTHROUGH && type2 == MTRR_TYPE_WRBACK))
return MTRR_TYPE_WRTHROUGH;
if (type1 != type2)
return MTRR_TYPE_UNCACHABLE;
return type1;
}
static void rm_map_entry_at(int idx)
{
cache_map_n--;
if (cache_map_n > idx) {
memmove(cache_map + idx, cache_map + idx + 1,
sizeof(*cache_map) * (cache_map_n - idx));
}
}
/*
* Add an entry into cache_map at a specific index. Merges adjacent entries if
* appropriate. Return the number of merges for correcting the scan index
* (this is needed as merging will reduce the number of entries, which will
* result in skipping entries in future iterations if the scan index isn't
* corrected).
* Note that the corrected index can never go below -1 (resulting in being 0 in
* the next scan iteration), as "2" is returned only if the current index is
* larger than zero.
*/
static int add_map_entry_at(u64 start, u64 end, u8 type, int idx)
{
bool merge_prev = false, merge_next = false;
if (start >= end)
return 0;
if (idx > 0) {
struct cache_map *prev = cache_map + idx - 1;
if (!prev->fixed && start == prev->end && type == prev->type)
merge_prev = true;
}
if (idx < cache_map_n) {
struct cache_map *next = cache_map + idx;
if (!next->fixed && end == next->start && type == next->type)
merge_next = true;
}
if (merge_prev && merge_next) {
cache_map[idx - 1].end = cache_map[idx].end;
rm_map_entry_at(idx);
return 2;
}
if (merge_prev) {
cache_map[idx - 1].end = end;
return 1;
}
if (merge_next) {
cache_map[idx].start = start;
return 1;
}
/* Sanity check: the array should NEVER be too small! */
if (cache_map_n == cache_map_size) {
WARN(1, "MTRR cache mode memory map exhausted!\n");
cache_map_n = cache_map_fixed;
return 0;
}
if (cache_map_n > idx) {
memmove(cache_map + idx + 1, cache_map + idx,
sizeof(*cache_map) * (cache_map_n - idx));
}
cache_map[idx].start = start;
cache_map[idx].end = end;
cache_map[idx].type = type;
cache_map[idx].fixed = 0;
cache_map_n++;
return 0;
}
/* Clear a part of an entry. Return 1 if start of entry is still valid. */
static int clr_map_range_at(u64 start, u64 end, int idx)
{
int ret = start != cache_map[idx].start;
u64 tmp;
if (start == cache_map[idx].start && end == cache_map[idx].end) {
rm_map_entry_at(idx);
} else if (start == cache_map[idx].start) {
cache_map[idx].start = end;
} else if (end == cache_map[idx].end) {
cache_map[idx].end = start;
} else {
tmp = cache_map[idx].end;
cache_map[idx].end = start;
add_map_entry_at(end, tmp, cache_map[idx].type, idx + 1);
}
return ret;
}
/*
* Add MTRR to the map. The current map is scanned and each part of the MTRR
* either overlapping with an existing entry or with a hole in the map is
* handled separately.
*/
static void add_map_entry(u64 start, u64 end, u8 type)
{
u8 new_type, old_type;
u64 tmp;
int i;
for (i = 0; i < cache_map_n && start < end; i++) {
if (start >= cache_map[i].end)
continue;
if (start < cache_map[i].start) {
/* Region start has no overlap. */
tmp = min(end, cache_map[i].start);
i -= add_map_entry_at(start, tmp, type, i);
start = tmp;
continue;
}
new_type = get_effective_type(type, cache_map[i].type);
old_type = cache_map[i].type;
if (cache_map[i].fixed || new_type == old_type) {
/* Cut off start of new entry. */
start = cache_map[i].end;
continue;
}
/* Handle only overlapping part of region. */
tmp = min(end, cache_map[i].end);
i += clr_map_range_at(start, tmp, i);
i -= add_map_entry_at(start, tmp, new_type, i);
start = tmp;
}
/* Add rest of region after last map entry (rest might be empty). */
add_map_entry_at(start, end, type, i);
}
/* Add variable MTRRs to cache map. */
static void map_add_var(void)
{
u64 start, size;
unsigned int i;
u8 type;
/*
* Add AMD TOP_MEM2 area. Can't be added in mtrr_build_map(), as it
* needs to be added again when rebuilding the map due to potentially
* having moved as a result of variable MTRRs for memory below 4GB.
*/
if (mtrr_tom2) {
add_map_entry(BIT_ULL(32), mtrr_tom2, MTRR_TYPE_WRBACK);
cache_map[cache_map_n - 1].fixed = 1;
}
for (i = 0; i < num_var_ranges; i++) {
type = get_var_mtrr_state(i, &start, &size);
if (type != MTRR_TYPE_INVALID)
add_map_entry(start, start + size, type);
}
}
/*
* Rebuild map by replacing variable entries. Needs to be called when MTRR
* registers are being changed after boot, as such changes could include
* removals of registers, which are complicated to handle without rebuild of
* the map.
*/
void generic_rebuild_map(void)
{
if (mtrr_if != &generic_mtrr_ops)
return;
cache_map_n = cache_map_fixed;
map_add_var();
}
static unsigned int __init get_cache_map_size(void)
{
return cache_map_fixed + 2 * num_var_ranges + (mtrr_tom2 != 0);
}
/* Build the cache_map containing the cache modes per memory range. */
void __init mtrr_build_map(void)
{
u64 start, end, size;
unsigned int i;
u8 type;
/* Add fixed MTRRs, optimize for adjacent entries with same type. */
if (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED) {
/*
* Start with 64k size fixed entries, preset 1st one (hence the
* loop below is starting with index 1).
*/
start = 0;
end = size = 0x10000;
type = mtrr_state.fixed_ranges[0];
for (i = 1; i < MTRR_NUM_FIXED_RANGES; i++) {
/* 8 64k entries, then 16 16k ones, rest 4k. */
if (i == 8 || i == 24)
size >>= 2;
if (mtrr_state.fixed_ranges[i] != type) {
add_map_entry(start, end, type);
start = end;
type = mtrr_state.fixed_ranges[i];
}
end += size;
}
add_map_entry(start, end, type);
}
/* Mark fixed, they take precedence. */
for (i = 0; i < cache_map_n; i++)
cache_map[i].fixed = 1;
cache_map_fixed = cache_map_n;
map_add_var();
pr_info("MTRR map: %u entries (%u fixed + %u variable; max %u), built from %u variable MTRRs\n",
cache_map_n, cache_map_fixed, cache_map_n - cache_map_fixed,
get_cache_map_size(), num_var_ranges + (mtrr_tom2 != 0));
if (mtrr_debug) {
for (i = 0; i < cache_map_n; i++) {
pr_info("%3u: %016llx-%016llx %s\n", i,
cache_map[i].start, cache_map[i].end - 1,
mtrr_attrib_to_str(cache_map[i].type));
}
}
}
/* Copy the cache_map from __initdata memory to dynamically allocated one. */
void __init mtrr_copy_map(void)
{
unsigned int new_size = get_cache_map_size();
if (!mtrr_state.enabled || !new_size) {
cache_map = NULL;
return;
}
mutex_lock(&mtrr_mutex);
cache_map = kcalloc(new_size, sizeof(*cache_map), GFP_KERNEL);
if (cache_map) {
memmove(cache_map, init_cache_map,
cache_map_n * sizeof(*cache_map));
cache_map_size = new_size;
} else {
mtrr_state.enabled = 0;
pr_err("MTRRs disabled due to allocation failure for lookup map.\n");
}
mutex_unlock(&mtrr_mutex);
}
/**
* mtrr_overwrite_state - set static MTRR state
*
* Used to set MTRR state via different means (e.g. with data obtained from
* a hypervisor).
* Is allowed only for special cases when running virtualized. Must be called
* from the x86_init.hyper.init_platform() hook. It can be called only once.
* The MTRR state can't be changed afterwards. To ensure that, X86_FEATURE_MTRR
* is cleared.
*
* @var: MTRR variable range array to use
* @num_var: length of the @var array
* @def_type: default caching type
*/
void mtrr_overwrite_state(struct mtrr_var_range *var, unsigned int num_var,
mtrr_type def_type)
{
unsigned int i;
/* Only allowed to be called once before mtrr_bp_init(). */
if (WARN_ON_ONCE(mtrr_state_set))
return;
/* Only allowed when running virtualized. */
if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
return;
/*
* Only allowed for special virtualization cases:
* - when running as Hyper-V, SEV-SNP guest using vTOM
* - when running as Xen PV guest
* - when running as SEV-SNP or TDX guest to avoid unnecessary
* VMM communication/Virtualization exceptions (#VC, #VE)
*/
if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP) &&
!hv_is_isolation_supported() &&
!cpu_feature_enabled(X86_FEATURE_XENPV) &&
!cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
return;
/* Disable MTRR in order to disable MTRR modifications. */
setup_clear_cpu_cap(X86_FEATURE_MTRR);
if (var) {
if (num_var > MTRR_MAX_VAR_RANGES) {
pr_warn("Trying to overwrite MTRR state with %u variable entries\n",
num_var);
num_var = MTRR_MAX_VAR_RANGES;
}
for (i = 0; i < num_var; i++)
mtrr_state.var_ranges[i] = var[i];
num_var_ranges = num_var;
}
mtrr_state.def_type = def_type;
mtrr_state.enabled |= MTRR_STATE_MTRR_ENABLED;
mtrr_state_set = 1;
}
static u8 type_merge(u8 type, u8 new_type, u8 *uniform)
{
u8 effective_type;
if (type == MTRR_TYPE_INVALID)
return new_type;
effective_type = get_effective_type(type, new_type);
if (type != effective_type)
*uniform = 0;
return effective_type;
}
/**
* mtrr_type_lookup - look up memory type in MTRR
*
* @start: Begin of the physical address range
* @end: End of the physical address range
* @uniform: output argument:
* - 1: the returned MTRR type is valid for the whole region
* - 0: otherwise
*
* Return Values:
* MTRR_TYPE_(type) - The effective MTRR type for the region
* MTRR_TYPE_INVALID - MTRR is disabled
*/
u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform)
{
u8 type = MTRR_TYPE_INVALID;
unsigned int i;
if (!mtrr_state_set) {
/* Uniformity is unknown. */
*uniform = 0;
return MTRR_TYPE_UNCACHABLE;
}
*uniform = 1;
if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED))
return MTRR_TYPE_UNCACHABLE;
for (i = 0; i < cache_map_n && start < end; i++) {
/* Region after current map entry? -> continue with next one. */
if (start >= cache_map[i].end)
continue;
/* Start of region not covered by current map entry? */
if (start < cache_map[i].start) {
/* At least some part of region has default type. */
type = type_merge(type, mtrr_state.def_type, uniform);
/* End of region not covered, too? -> lookup done. */
if (end <= cache_map[i].start)
return type;
}
/* At least part of region covered by map entry. */
type = type_merge(type, cache_map[i].type, uniform);
start = cache_map[i].end;
}
/* End of region past last entry in map? -> use default type. */
if (start < end)
type = type_merge(type, mtrr_state.def_type, uniform);
return type;
}
/* Get the MSR pair relating to a var range */
static void
get_mtrr_var_range(unsigned int index, struct mtrr_var_range *vr)
{
rdmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
rdmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
}
/* Fill the MSR pair relating to a var range */
void fill_mtrr_var_range(unsigned int index,
u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi)
{
struct mtrr_var_range *vr;
vr = mtrr_state.var_ranges;
vr[index].base_lo = base_lo;
vr[index].base_hi = base_hi;
vr[index].mask_lo = mask_lo;
vr[index].mask_hi = mask_hi;
}
static void get_fixed_ranges(mtrr_type *frs)
{
unsigned int *p = (unsigned int *)frs;
int i;
k8_check_syscfg_dram_mod_en();
rdmsr(MSR_MTRRfix64K_00000, p[0], p[1]);
for (i = 0; i < 2; i++)
rdmsr(MSR_MTRRfix16K_80000 + i, p[2 + i * 2], p[3 + i * 2]);
for (i = 0; i < 8; i++)
rdmsr(MSR_MTRRfix4K_C0000 + i, p[6 + i * 2], p[7 + i * 2]);
}
void mtrr_save_fixed_ranges(void *info)
{
if (boot_cpu_has(X86_FEATURE_MTRR))
get_fixed_ranges(mtrr_state.fixed_ranges);
}
static unsigned __initdata last_fixed_start;
static unsigned __initdata last_fixed_end;
static mtrr_type __initdata last_fixed_type;
static void __init print_fixed_last(void)
{
if (!last_fixed_end)
return;
pr_info(" %05X-%05X %s\n", last_fixed_start,
last_fixed_end - 1, mtrr_attrib_to_str(last_fixed_type));
last_fixed_end = 0;
}
static void __init update_fixed_last(unsigned base, unsigned end,
mtrr_type type)
{
last_fixed_start = base;
last_fixed_end = end;
last_fixed_type = type;
}
static void __init
print_fixed(unsigned base, unsigned step, const mtrr_type *types)
{
unsigned i;
for (i = 0; i < 8; ++i, ++types, base += step) {
if (last_fixed_end == 0) {
update_fixed_last(base, base + step, *types);
continue;
}
if (last_fixed_end == base && last_fixed_type == *types) {
last_fixed_end = base + step;
continue;
}
/* new segments: gap or different type */
print_fixed_last();
update_fixed_last(base, base + step, *types);
}
}
static void __init print_mtrr_state(void)
{
unsigned int i;
int high_width;
pr_info("MTRR default type: %s\n",
mtrr_attrib_to_str(mtrr_state.def_type));
if (mtrr_state.have_fixed) {
pr_info("MTRR fixed ranges %sabled:\n",
((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) &&
(mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ?
"en" : "dis");
print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0);
for (i = 0; i < 2; ++i)
print_fixed(0x80000 + i * 0x20000, 0x04000,
mtrr_state.fixed_ranges + (i + 1) * 8);
for (i = 0; i < 8; ++i)
print_fixed(0xC0000 + i * 0x08000, 0x01000,
mtrr_state.fixed_ranges + (i + 3) * 8);
/* tail */
print_fixed_last();
}
pr_info("MTRR variable ranges %sabled:\n",
mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis");
high_width = (boot_cpu_data.x86_phys_bits - (32 - PAGE_SHIFT) + 3) / 4;
for (i = 0; i < num_var_ranges; ++i) {
if (mtrr_state.var_ranges[i].mask_lo & MTRR_PHYSMASK_V)
pr_info(" %u base %0*X%05X000 mask %0*X%05X000 %s\n",
i,
high_width,
mtrr_state.var_ranges[i].base_hi,
mtrr_state.var_ranges[i].base_lo >> 12,
high_width,
mtrr_state.var_ranges[i].mask_hi,
mtrr_state.var_ranges[i].mask_lo >> 12,
mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo &
MTRR_PHYSBASE_TYPE));
else
pr_info(" %u disabled\n", i);
}
if (mtrr_tom2)
pr_info("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20);
}
/* Grab all of the MTRR state for this CPU into *state */
bool __init get_mtrr_state(void)
{
struct mtrr_var_range *vrs;
unsigned lo, dummy;
unsigned int i;
vrs = mtrr_state.var_ranges;
rdmsr(MSR_MTRRcap, lo, dummy);
mtrr_state.have_fixed = lo & MTRR_CAP_FIX;
for (i = 0; i < num_var_ranges; i++)
get_mtrr_var_range(i, &vrs[i]);
if (mtrr_state.have_fixed)
get_fixed_ranges(mtrr_state.fixed_ranges);
rdmsr(MSR_MTRRdefType, lo, dummy);
mtrr_state.def_type = lo & MTRR_DEF_TYPE_TYPE;
mtrr_state.enabled = (lo & MTRR_DEF_TYPE_ENABLE) >> MTRR_STATE_SHIFT;
if (amd_special_default_mtrr()) {
unsigned low, high;
/* TOP_MEM2 */
rdmsr(MSR_K8_TOP_MEM2, low, high);
mtrr_tom2 = high;
mtrr_tom2 <<= 32;
mtrr_tom2 |= low;
mtrr_tom2 &= 0xffffff800000ULL;
}
if (mtrr_debug)
print_mtrr_state();
mtrr_state_set = 1;
return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED);
}
/* Some BIOS's are messed up and don't set all MTRRs the same! */
void __init mtrr_state_warn(void)
{
unsigned long mask = smp_changes_mask;
if (!mask)
return;
if (mask & MTRR_CHANGE_MASK_FIXED)
pr_warn("mtrr: your CPUs had inconsistent fixed MTRR settings\n");
if (mask & MTRR_CHANGE_MASK_VARIABLE)
pr_warn("mtrr: your CPUs had inconsistent variable MTRR settings\n");
if (mask & MTRR_CHANGE_MASK_DEFTYPE)
pr_warn("mtrr: your CPUs had inconsistent MTRRdefType settings\n");
pr_info("mtrr: probably your BIOS does not setup all CPUs.\n");
pr_info("mtrr: corrected configuration.\n");
}
/*
* Doesn't attempt to pass an error out to MTRR users
* because it's quite complicated in some cases and probably not
* worth it because the best error handling is to ignore it.
*/
void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b)
{
if (wrmsr_safe(msr, a, b) < 0) {
pr_err("MTRR: CPU %u: Writing MSR %x to %x:%x failed\n",
smp_processor_id(), msr, a, b);
}
}
/**
* set_fixed_range - checks & updates a fixed-range MTRR if it
* differs from the value it should have
* @msr: MSR address of the MTTR which should be checked and updated
* @changed: pointer which indicates whether the MTRR needed to be changed
* @msrwords: pointer to the MSR values which the MSR should have
*/
static void set_fixed_range(int msr, bool *changed, unsigned int *msrwords)
{
unsigned lo, hi;
rdmsr(msr, lo, hi);
if (lo != msrwords[0] || hi != msrwords[1]) {
mtrr_wrmsr(msr, msrwords[0], msrwords[1]);
*changed = true;
}
}
/**
* generic_get_free_region - Get a free MTRR.
* @base: The starting (base) address of the region.
* @size: The size (in bytes) of the region.
* @replace_reg: mtrr index to be replaced; set to invalid value if none.
*
* Returns: The index of the region on success, else negative on error.
*/
int
generic_get_free_region(unsigned long base, unsigned long size, int replace_reg)
{
unsigned long lbase, lsize;
mtrr_type ltype;
int i, max;
max = num_var_ranges;
if (replace_reg >= 0 && replace_reg < max)
return replace_reg;
for (i = 0; i < max; ++i) {
mtrr_if->get(i, &lbase, &lsize, <ype);
if (lsize == 0)
return i;
}
return -ENOSPC;
}
static void generic_get_mtrr(unsigned int reg, unsigned long *base,
unsigned long *size, mtrr_type *type)
{
u32 mask_lo, mask_hi, base_lo, base_hi;
unsigned int hi;
u64 tmp, mask;
/*
* get_mtrr doesn't need to update mtrr_state, also it could be called
* from any cpu, so try to print it out directly.
*/
get_cpu();
rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);
if (!(mask_lo & MTRR_PHYSMASK_V)) {
/* Invalid (i.e. free) range */
*base = 0;
*size = 0;
*type = 0;
goto out_put_cpu;
}
rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);
/* Work out the shifted address mask: */
tmp = (u64)mask_hi << 32 | (mask_lo & PAGE_MASK);
mask = (u64)phys_hi_rsvd << 32 | tmp;
/* Expand tmp with high bits to all 1s: */
hi = fls64(tmp);
if (hi > 0) {
tmp |= ~((1ULL<<(hi - 1)) - 1);
if (tmp != mask) {
pr_warn("mtrr: your BIOS has configured an incorrect mask, fixing it.\n");
add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
mask = tmp;
}
}
/*
* This works correctly if size is a power of two, i.e. a
* contiguous range:
*/
*size = -mask >> PAGE_SHIFT;
*base = (u64)base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
*type = base_lo & MTRR_PHYSBASE_TYPE;
out_put_cpu:
put_cpu();
}
/**
* set_fixed_ranges - checks & updates the fixed-range MTRRs if they
* differ from the saved set
* @frs: pointer to fixed-range MTRR values, saved by get_fixed_ranges()
*/
static int set_fixed_ranges(mtrr_type *frs)
{
unsigned long long *saved = (unsigned long long *)frs;
bool changed = false;
int block = -1, range;
k8_check_syscfg_dram_mod_en();
while (fixed_range_blocks[++block].ranges) {
for (range = 0; range < fixed_range_blocks[block].ranges; range++)
set_fixed_range(fixed_range_blocks[block].base_msr + range,
&changed, (unsigned int *)saved++);
}
return changed;
}
/*
* Set the MSR pair relating to a var range.
* Returns true if changes are made.
*/
static bool set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr)
{
unsigned int lo, hi;
bool changed = false;
rdmsr(MTRRphysBase_MSR(index), lo, hi);
if ((vr->base_lo & ~MTRR_PHYSBASE_RSVD) != (lo & ~MTRR_PHYSBASE_RSVD)
|| (vr->base_hi & ~phys_hi_rsvd) != (hi & ~phys_hi_rsvd)) {
mtrr_wrmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
changed = true;
}
rdmsr(MTRRphysMask_MSR(index), lo, hi);
if ((vr->mask_lo & ~MTRR_PHYSMASK_RSVD) != (lo & ~MTRR_PHYSMASK_RSVD)
|| (vr->mask_hi & ~phys_hi_rsvd) != (hi & ~phys_hi_rsvd)) {
mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
changed = true;
}
return changed;
}
static u32 deftype_lo, deftype_hi;
/**
* set_mtrr_state - Set the MTRR state for this CPU.
*
* NOTE: The CPU must already be in a safe state for MTRR changes, including
* measures that only a single CPU can be active in set_mtrr_state() in
* order to not be subject to races for usage of deftype_lo. This is
* accomplished by taking cache_disable_lock.
* RETURNS: 0 if no changes made, else a mask indicating what was changed.
*/
static unsigned long set_mtrr_state(void)
{
unsigned long change_mask = 0;
unsigned int i;
for (i = 0; i < num_var_ranges; i++) {
if (set_mtrr_var_ranges(i, &mtrr_state.var_ranges[i]))
change_mask |= MTRR_CHANGE_MASK_VARIABLE;
}
if (mtrr_state.have_fixed && set_fixed_ranges(mtrr_state.fixed_ranges))
change_mask |= MTRR_CHANGE_MASK_FIXED;
/*
* Set_mtrr_restore restores the old value of MTRRdefType,
* so to set it we fiddle with the saved value:
*/
if ((deftype_lo & MTRR_DEF_TYPE_TYPE) != mtrr_state.def_type ||
((deftype_lo & MTRR_DEF_TYPE_ENABLE) >> MTRR_STATE_SHIFT) != mtrr_state.enabled) {
deftype_lo = (deftype_lo & MTRR_DEF_TYPE_DISABLE) |
mtrr_state.def_type |
(mtrr_state.enabled << MTRR_STATE_SHIFT);
change_mask |= MTRR_CHANGE_MASK_DEFTYPE;
}
return change_mask;
}
void mtrr_disable(void)
{
/* Save MTRR state */
rdmsr(MSR_MTRRdefType, deftype_lo, deftype_hi);
/* Disable MTRRs, and set the default type to uncached */
mtrr_wrmsr(MSR_MTRRdefType, deftype_lo & MTRR_DEF_TYPE_DISABLE, deftype_hi);
}
void mtrr_enable(void)
{
/* Intel (P6) standard MTRRs */
mtrr_wrmsr(MSR_MTRRdefType, deftype_lo, deftype_hi);
}
void mtrr_generic_set_state(void)
{
unsigned long mask, count;
/* Actually set the state */
mask = set_mtrr_state();
/* Use the atomic bitops to update the global mask */
for (count = 0; count < sizeof(mask) * 8; ++count) {
if (mask & 0x01)
set_bit(count, &smp_changes_mask);
mask >>= 1;
}
}
/**
* generic_set_mtrr - set variable MTRR register on the local CPU.
*
* @reg: The register to set.
* @base: The base address of the region.
* @size: The size of the region. If this is 0 the region is disabled.
* @type: The type of the region.
*
* Returns nothing.
*/
static void generic_set_mtrr(unsigned int reg, unsigned long base,
unsigned long size, mtrr_type type)
{
unsigned long flags;
struct mtrr_var_range *vr;
vr = &mtrr_state.var_ranges[reg];
local_irq_save(flags);
cache_disable();
if (size == 0) {
/*
* The invalid bit is kept in the mask, so we simply
* clear the relevant mask register to disable a range.
*/
mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0);
memset(vr, 0, sizeof(struct mtrr_var_range));
} else {
vr->base_lo = base << PAGE_SHIFT | type;
vr->base_hi = (base >> (32 - PAGE_SHIFT)) & ~phys_hi_rsvd;
vr->mask_lo = -size << PAGE_SHIFT | MTRR_PHYSMASK_V;
vr->mask_hi = (-size >> (32 - PAGE_SHIFT)) & ~phys_hi_rsvd;
mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi);
mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi);
}
cache_enable();
local_irq_restore(flags);
}
int generic_validate_add_page(unsigned long base, unsigned long size,
unsigned int type)
{
unsigned long lbase, last;
/*
* For Intel PPro stepping <= 7
* must be 4 MiB aligned and not touch 0x70000000 -> 0x7003FFFF
*/
if (mtrr_if == &generic_mtrr_ops && boot_cpu_data.x86 == 6 &&
boot_cpu_data.x86_model == 1 &&
boot_cpu_data.x86_stepping <= 7) {
if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) {
pr_warn("mtrr: base(0x%lx000) is not 4 MiB aligned\n", base);
return -EINVAL;
}
if (!(base + size < 0x70000 || base > 0x7003F) &&
(type == MTRR_TYPE_WRCOMB
|| type == MTRR_TYPE_WRBACK)) {
pr_warn("mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n");
return -EINVAL;
}
}
/*
* Check upper bits of base and last are equal and lower bits are 0
* for base and 1 for last
*/
last = base + size - 1;
for (lbase = base; !(lbase & 1) && (last & 1);
lbase = lbase >> 1, last = last >> 1)
;
if (lbase != last) {
pr_warn("mtrr: base(0x%lx000) is not aligned on a size(0x%lx000) boundary\n", base, size);
return -EINVAL;
}
return 0;
}
static int generic_have_wrcomb(void)
{
unsigned long config, dummy;
rdmsr(MSR_MTRRcap, config, dummy);
return config & MTRR_CAP_WC;
}
int positive_have_wrcomb(void)
{
return 1;
}
/*
* Generic structure...
*/
const struct mtrr_ops generic_mtrr_ops = {
.get = generic_get_mtrr,
.get_free_region = generic_get_free_region,
.set = generic_set_mtrr,
.validate_add_page = generic_validate_add_page,
.have_wrcomb = generic_have_wrcomb,
};
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