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/* SPDX-License-Identifier: GPL-2.0-only */
#include <cpu/cpu.h>
#include <cpu/x86/mtrr.h>
#include <cpu/x86/msr.h>
#include <console/console.h>
#include <commonlib/bsd/helpers.h>
#include <stdint.h>
/* Get first available variable MTRR.
* Returns var# if available, else returns -1.
*/
int get_free_var_mtrr(void)
{
msr_t maskm;
int vcnt;
int i;
vcnt = get_var_mtrr_count();
/* Identify the first var mtrr which is not valid. */
for (i = 0; i < vcnt; i++) {
maskm = rdmsr(MTRR_PHYS_MASK(i));
if ((maskm.lo & MTRR_PHYS_MASK_VALID) == 0)
return i;
}
/* No free var mtrr. */
return -1;
}
void set_var_mtrr(
unsigned int reg, unsigned int base, unsigned int size,
unsigned int type)
{
/* Bit 32-35 of MTRRphysMask should be set to 1 */
/* FIXME: It only support 4G less range */
msr_t basem, maskm;
if (!IS_POWER_OF_2(size))
printk(BIOS_ERR, "MTRR Error: size %#x is not a power of two\n", size);
if (size < 4 * KiB)
printk(BIOS_ERR, "MTRR Error: size %#x smaller than 4KiB\n", size);
if (base % size != 0)
printk(BIOS_ERR, "MTRR Error: base %#x must be aligned to size %#x\n", base,
size);
basem.lo = base | type;
basem.hi = 0;
wrmsr(MTRR_PHYS_BASE(reg), basem);
maskm.lo = ~(size - 1) | MTRR_PHYS_MASK_VALID;
maskm.hi = (1 << (cpu_phys_address_size() - 32)) - 1;
wrmsr(MTRR_PHYS_MASK(reg), maskm);
}
void clear_all_var_mtrr(void)
{
msr_t mtrr = {0, 0};
int vcnt;
int i;
vcnt = get_var_mtrr_count();
for (i = 0; i < vcnt; i++) {
wrmsr(MTRR_PHYS_MASK(i), mtrr);
wrmsr(MTRR_PHYS_BASE(i), mtrr);
}
}
void var_mtrr_context_init(struct var_mtrr_context *ctx)
{
ctx->max_var_mtrrs = get_var_mtrr_count();
ctx->used_var_mtrrs = 0;
}
int var_mtrr_set(struct var_mtrr_context *ctx, uintptr_t addr, size_t size, int type)
{
const uint32_t upper_mask = (1U << (cpu_phys_address_size() - 32)) - 1;
/* Utilize additional MTRRs if the specified size is greater than the
base address alignment. */
while (size != 0) {
uint32_t addr_lsb;
uint32_t size_msb;
uint32_t mtrr_size;
msr_t base;
msr_t mask;
if (ctx->used_var_mtrrs >= ctx->max_var_mtrrs) {
printk(BIOS_ERR, "No more variable MTRRs: %d\n",
ctx->max_var_mtrrs);
return -1;
}
addr_lsb = fls(addr);
size_msb = fms(size);
/* All MTRR entries need to have their base aligned to the mask
size. The maximum size is calculated by a function of the
min base bit set and maximum size bit set. */
if (addr_lsb > size_msb)
mtrr_size = 1 << size_msb;
else
mtrr_size = 1 << addr_lsb;
base.hi = (uint64_t)addr >> 32;
base.lo = addr | type;
mask.hi = upper_mask;
mask.lo = ~(mtrr_size - 1) | MTRR_PHYS_MASK_VALID;
ctx->mtrr[ctx->used_var_mtrrs].base = base;
ctx->mtrr[ctx->used_var_mtrrs].mask = mask;
ctx->used_var_mtrrs++;
size -= mtrr_size;
addr += mtrr_size;
}
return 0;
}
/* Romstage sets up a MTRR context in cbmem and sets up this pointer in postcar stage. */
__attribute__((used, __section__(".module_parameters"))) const volatile uintptr_t post_car_mtrrs;
void commit_mtrr_setup(const struct var_mtrr_context *ctx)
{
clear_all_var_mtrr();
for (int i = 0; i < ctx->used_var_mtrrs; i++) {
wrmsr(MTRR_PHYS_BASE(i), ctx->mtrr[i].base);
wrmsr(MTRR_PHYS_MASK(i), ctx->mtrr[i].mask);
}
/* Enable MTRR */
msr_t mtrr_def_type = rdmsr(MTRR_DEF_TYPE_MSR);
mtrr_def_type.lo &= MTRR_DEF_TYPE_MASK;
mtrr_def_type.lo |= MTRR_DEF_TYPE_EN;
wrmsr(MTRR_DEF_TYPE_MSR, mtrr_def_type);
}
void postcar_mtrr_setup(void)
{
commit_mtrr_setup((const struct var_mtrr_context *)post_car_mtrrs);
}
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