src/soc/amd/common/block/cpu/smm/smm_relocate.c

/* SPDX-License-Identifier: GPL-2.0-only */

#include <cpu/x86/mtrr.h>
#include <cpu/x86/mp.h>
#include <amdblocks/cpu.h>
#include <amdblocks/smm.h>
#include <console/console.h>
#include <cpu/amd/amd64_save_state.h>
#include <cpu/amd/msr.h>
#include <cpu/amd/mtrr.h>
#include <cpu/cpu.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/smm.h>
#include <types.h>

/* AP MTRRs will be synced to the BSP in the SIPI vector so set them up before MP init. */
static void pre_mp_init(void)
{
	const msr_t syscfg = rdmsr(SYSCFG_MSR);
	if (syscfg.lo & SYSCFG_MSR_TOM2WB)
		x86_setup_mtrrs_with_detect_no_above_4gb();
	else
		x86_setup_mtrrs_with_detect();
	x86_mtrr_check();
}

static void get_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");

	uintptr_t tseg_base;
	size_t tseg_size;

	smm_region(&tseg_base, &tseg_size);

	if (!IS_ALIGNED(tseg_base, tseg_size)) {
		printk(BIOS_ERR, "TSEG base not aligned to TSEG size\n");
		return;
	}
	/* Minimum granularity for TSEG MSRs */
	if (tseg_size < 128 * KiB) {
		printk(BIOS_ERR, "TSEG size (0x%zx) too small\n", tseg_size);
		return;
	}


	smm_subregion(SMM_SUBREGION_HANDLER, perm_smbase, perm_smsize);
	*smm_save_state_size = sizeof(amd64_smm_state_save_area_t);
}

static void tseg_valid(void)
{
	msr_t mask = rdmsr(SMM_MASK_MSR);
	mask.lo |= SMM_TSEG_VALID;

	wrmsr(SMM_MASK_MSR, mask);
}

static void smm_relocation_handler(void)
{
	uintptr_t tseg_base;
	size_t tseg_size;

	smm_region(&tseg_base, &tseg_size);

	msr_t msr;
	msr.raw = tseg_base;
	wrmsr(SMM_ADDR_MSR, msr);

	msr.lo = ~(tseg_size - 1);
	msr.lo |= SMM_TSEG_WB;
	msr.hi = (1 << (cpu_phys_address_size() - 32)) - 1;
	wrmsr(SMM_MASK_MSR, msr);

	uintptr_t smbase = smm_get_cpu_smbase(cpu_index());
	msr_t smm_base = {
		.raw = smbase
	};
	wrmsr(SMM_BASE_MSR, smm_base);

	tseg_valid();
	lock_smm();
}

const struct mp_ops amd_mp_ops_with_smm = {
	.pre_mp_init = pre_mp_init,
	.get_cpu_count = get_cpu_count,
	.get_smm_info = get_smm_info,
	.per_cpu_smm_trigger = smm_relocation_handler,
	.post_mp_init = global_smi_enable,
};