diff --git a/src/soc/amd/picasso/Makefile.inc b/src/soc/amd/picasso/Makefile.inc index c7b6fb8bc9..40275ee4bc 100644 --- a/src/soc/amd/picasso/Makefile.inc +++ b/src/soc/amd/picasso/Makefile.inc @@ -31,6 +31,7 @@ romstage-y += southbridge.c romstage-$(CONFIG_HAVE_SMI_HANDLER) += smi_util.c romstage-y += soc_util.c romstage-y += psp.c +romstage-y += mtrr.c verstage-y += gpio.c verstage-y += i2c.c diff --git a/src/soc/amd/picasso/include/soc/mtrr.h b/src/soc/amd/picasso/include/soc/mtrr.h new file mode 100644 index 0000000000..4372ca4f5d --- /dev/null +++ b/src/soc/amd/picasso/include/soc/mtrr.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* This file is part of the coreboot project. */ + +#ifndef __PICASSO_MTRR_H__ +#define __PICASSO_MTRR_H__ + +void picasso_save_mtrrs(void); +void picasso_restore_mtrrs(void); + +#endif /* __PICASSO_MTRR_H__ */ diff --git a/src/soc/amd/picasso/mtrr.c b/src/soc/amd/picasso/mtrr.c new file mode 100644 index 0000000000..fe142f8fc1 --- /dev/null +++ b/src/soc/amd/picasso/mtrr.c @@ -0,0 +1,112 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* This file is part of the coreboot project. */ + +#include +#include +#include +#include +#include +#include + +/* Picasso defines 8 Variable MTRRs */ +#define MAX_VARIABLE_MTRRS 8 +#define SYS_CFG_MTRR_BITS ( \ +SYSCFG_MSR_TOM2WB | \ +SYSCFG_MSR_TOM2En | \ +SYSCFG_MSR_MtrrVarDramEn | \ +SYSCFG_MSR_MtrrFixDramModEn | \ +SYSCFG_MSR_MtrrFixDramEn \ +) + +static const unsigned int fixed_mtrr_offsets[] = { + MTRR_FIX_64K_00000, + MTRR_FIX_16K_80000, + MTRR_FIX_16K_A0000, + MTRR_FIX_4K_C0000, + MTRR_FIX_4K_C8000, + MTRR_FIX_4K_D0000, + MTRR_FIX_4K_D8000, + MTRR_FIX_4K_E0000, + MTRR_FIX_4K_E8000, + MTRR_FIX_4K_F0000, + MTRR_FIX_4K_F8000, +}; + +static int mtrrs_saved; +static msr_t sys_cfg; +static msr_t mtrr_def; +static msr_t mtrr_base[MAX_VARIABLE_MTRRS]; +static msr_t mtrr_mask[MAX_VARIABLE_MTRRS]; +static msr_t fixed_mtrrs[ARRAY_SIZE(fixed_mtrr_offsets)]; + +void picasso_save_mtrrs(void) +{ + unsigned int i; + int mtrrs; + + mtrrs = get_var_mtrr_count(); + + ASSERT_MSG(mtrrs == MAX_VARIABLE_MTRRS, "Unexpected number of MTRRs\n"); + + for (i = 0; i < MAX_VARIABLE_MTRRS; ++i) { + mtrr_base[i] = rdmsr(MTRR_PHYS_BASE(i)); + mtrr_mask[i] = rdmsr(MTRR_PHYS_MASK(i)); + printk(BIOS_DEBUG, + "Saving Variable MTRR %d: Base: 0x%08x 0x%08x, Mask: 0x%08x 0x%08x\n", i, + mtrr_base[i].hi, mtrr_base[i].lo, mtrr_mask[i].hi, mtrr_mask[i].lo); + } + + for (i = 0; i < ARRAY_SIZE(fixed_mtrr_offsets); ++i) { + fixed_mtrrs[i] = rdmsr(fixed_mtrr_offsets[i]); + printk(BIOS_DEBUG, "Saving Fixed MTRR %u: 0x%08x 0x%08x\n", i, + fixed_mtrrs[i].hi, fixed_mtrrs[i].lo); + } + + mtrr_def = rdmsr(MTRR_DEF_TYPE_MSR); + printk(BIOS_DEBUG, "Saving Default Type MTRR: 0x%08x 0x%08x\n", mtrr_def.hi, + mtrr_def.lo); + + sys_cfg = rdmsr(SYSCFG_MSR); + printk(BIOS_DEBUG, "Saving SYS_CFG: 0x%08x 0x%08x\n", mtrr_def.hi, mtrr_def.lo); + + mtrrs_saved = 1; +} + +static void update_if_changed(unsigned int offset, msr_t expected) +{ + msr_t tmp = rdmsr(offset); + if (tmp.lo == expected.lo && tmp.hi == expected.hi) + return; + + printk(BIOS_INFO, "MSR %#x was modified: 0x%08x 0x%08x\n", offset, tmp.hi, tmp.lo); + wrmsr(offset, expected); +} + +void picasso_restore_mtrrs(void) +{ + unsigned int i; + msr_t tmp_sys_cfg; + + ASSERT_MSG(mtrrs_saved, "Must save MTRRs before restoring.\n"); + + for (i = 0; i < MAX_VARIABLE_MTRRS; ++i) { + update_if_changed(MTRR_PHYS_BASE(i), mtrr_base[i]); + update_if_changed(MTRR_PHYS_MASK(i), mtrr_mask[i]); + } + + for (i = 0; i < ARRAY_SIZE(fixed_mtrr_offsets); ++i) + update_if_changed(fixed_mtrr_offsets[i], fixed_mtrrs[i]); + + update_if_changed(MTRR_DEF_TYPE_MSR, mtrr_def); + + tmp_sys_cfg = rdmsr(SYSCFG_MSR); + + /* We only care about the MTRR bits in the SYSCFG register */ + if ((tmp_sys_cfg.lo & SYS_CFG_MTRR_BITS) != (sys_cfg.lo & SYS_CFG_MTRR_BITS)) { + printk(BIOS_INFO, "SYS_CFG was modified: 0x%08x 0x%08x\n", tmp_sys_cfg.hi, + tmp_sys_cfg.lo); + tmp_sys_cfg.lo &= ~SYS_CFG_MTRR_BITS; + tmp_sys_cfg.lo |= (sys_cfg.lo & SYS_CFG_MTRR_BITS); + wrmsr(SYSCFG_MSR, tmp_sys_cfg); + } +}