/* SPDX-License-Identifier: GPL-2.0-only */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void update_save_state(int cpu, uintptr_t curr_smbase, uintptr_t staggered_smbase, struct smm_relocation_params *relo_params) { u32 smbase; u32 iedbase; /* * The relocated handler runs with all CPUs concurrently. Therefore * stagger the entry points adjusting SMBASE downwards by save state * size * CPU num. */ smbase = staggered_smbase; iedbase = relo_params->ied_base; printk(BIOS_DEBUG, "New SMBASE=0x%08x IEDBASE=0x%08x\n", smbase, iedbase); /* * All threads need to set IEDBASE and SMBASE to the relocated * handler region. However, the save state location depends on the * smm_save_state_in_msrs field in the relocation parameters. If * smm_save_state_in_msrs is non-zero then the CPUs are relocating * the SMM handler in parallel, and each CPUs save state area is * located in their respective MSR space. If smm_save_state_in_msrs * is zero then the SMM relocation is happening serially so the * save state is at the same default location for all CPUs. */ if (relo_params->smm_save_state_in_msrs) { msr_t smbase_msr; msr_t iedbase_msr; smbase_msr.lo = smbase; smbase_msr.hi = 0; /* * According the BWG the IEDBASE MSR is in bits 63:32. It's * not clear why it differs from the SMBASE MSR. */ iedbase_msr.lo = 0; iedbase_msr.hi = iedbase; wrmsr(SMBASE_MSR, smbase_msr); wrmsr(IEDBASE_MSR, iedbase_msr); } else { em64t101_smm_state_save_area_t *save_state; save_state = (void *)(curr_smbase + SMM_DEFAULT_SIZE - sizeof(*save_state)); save_state->smbase = smbase; save_state->iedbase = iedbase; } } /* Returns 1 if SMM MSR save state was set. */ static int bsp_setup_msr_save_state(struct smm_relocation_params *relo_params) { msr_t smm_mca_cap; smm_mca_cap = rdmsr(SMM_MCA_CAP_MSR); if (smm_mca_cap.hi & SMM_CPU_SVRSTR_MASK) { msr_t smm_feature_control; smm_feature_control = rdmsr(SMM_FEATURE_CONTROL_MSR); smm_feature_control.hi = 0; smm_feature_control.lo |= SMM_CPU_SAVE_EN; wrmsr(SMM_FEATURE_CONTROL_MSR, smm_feature_control); relo_params->smm_save_state_in_msrs = 1; } return relo_params->smm_save_state_in_msrs; } /* * The relocation work is actually performed in SMM context, but the code * resides in the ramstage module. This occurs by trampolining from the default * SMRAM entry point to here. */ void smm_relocation_handler(int cpu, uintptr_t curr_smbase, uintptr_t staggered_smbase) { msr_t mtrr_cap; struct smm_relocation_params *relo_params = &smm_reloc_params; printk(BIOS_DEBUG, "In relocation handler: CPU %d\n", cpu); /* * Determine if the processor supports saving state in MSRs. If so, * enable it before the non-BSPs run so that SMM relocation can occur * in parallel in the non-BSP CPUs. */ if (cpu == 0) { /* * If smm_save_state_in_msrs is 1 then that means this is the * 2nd time through the relocation handler for the BSP. * Parallel SMM handler relocation is taking place. However, * it is desired to access other CPUs save state in the real * SMM handler. Therefore, disable the SMM save state in MSRs * feature. */ if (relo_params->smm_save_state_in_msrs) { msr_t smm_feature_control; smm_feature_control = rdmsr(SMM_FEATURE_CONTROL_MSR); smm_feature_control.lo &= ~SMM_CPU_SAVE_EN; wrmsr(SMM_FEATURE_CONTROL_MSR, smm_feature_control); } else if (bsp_setup_msr_save_state(relo_params)) /* * Just return from relocation handler if MSR save * state is enabled. In that case the BSP will come * back into the relocation handler to setup the new * SMBASE as well disabling SMM save state in MSRs. */ return; } /* Make appropriate changes to the save state map. */ update_save_state(cpu, curr_smbase, staggered_smbase, relo_params); /* Write SMRR MSRs based on indicated support. */ mtrr_cap = rdmsr(MTRR_CAP_MSR); if (mtrr_cap.lo & SMRR_SUPPORTED) write_smrr(relo_params); } static void fill_in_relocation_params(struct smm_relocation_params *params) { uintptr_t tseg_base; size_t tseg_size; /* All range registers are aligned to 4KiB */ const u32 rmask = ~(4 * KiB - 1); smm_region(&tseg_base, &tseg_size); if (!IS_ALIGNED(tseg_base, tseg_size)) { printk(BIOS_WARNING, "TSEG base not aligned with TSEG size! Not setting SMRR\n"); return; } smm_subregion(SMM_SUBREGION_CHIPSET, ¶ms->ied_base, ¶ms->ied_size); /* SMRR has 32-bits of valid address aligned to 4KiB. */ params->smrr_base.lo = (tseg_base & rmask) | MTRR_TYPE_WRBACK; params->smrr_base.hi = 0; params->smrr_mask.lo = (~(tseg_size - 1) & rmask) | MTRR_PHYS_MASK_VALID; params->smrr_mask.hi = 0; } static void setup_ied_area(struct smm_relocation_params *params) { char *ied_base; struct ied_header ied = { .signature = "INTEL RSVD", .size = params->ied_size, .reserved = {0}, }; ied_base = (void *)params->ied_base; printk(BIOS_DEBUG, "IED base = 0x%08x\n", (u32)params->ied_base); printk(BIOS_DEBUG, "IED size = 0x%08x\n", (u32)params->ied_size); /* Place IED header at IEDBASE. */ memcpy(ied_base, &ied, sizeof(ied)); /* Zero out 32KiB at IEDBASE + 1MiB */ memset(ied_base + 1 * MiB, 0, 32 * KiB); } void smm_info(uintptr_t *perm_smbase, size_t *perm_smsize, size_t *smm_save_state_size) { printk(BIOS_DEBUG, "Setting up SMI for CPU\n"); fill_in_relocation_params(&smm_reloc_params); smm_subregion(SMM_SUBREGION_HANDLER, perm_smbase, perm_smsize); if (smm_reloc_params.ied_size) setup_ied_area(&smm_reloc_params); *smm_save_state_size = sizeof(em64t101_smm_state_save_area_t); } void smm_initialize(void) { /* Clear the SMM state in the southbridge. */ smm_southbridge_clear_state(); /* * Run the relocation handler for on the BSP to check and set up * parallel SMM relocation. */ smm_initiate_relocation(); if (smm_reloc_params.smm_save_state_in_msrs) printk(BIOS_DEBUG, "Doing parallel SMM relocation.\n"); } void smm_relocate(void) { /* * If smm_save_state_in_msrs is non-zero then parallel SMM relocation * shall take place. Run the relocation handler a second time on the * BSP to do * the final move. For APs, a relocation handler always * needs to be run. */ if (smm_reloc_params.smm_save_state_in_msrs) smm_initiate_relocation_parallel(); else if (!boot_cpu()) smm_initiate_relocation(); }