cpu.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <cpu/x86/mp.h>
#include <stdint.h>
#include <cpu/intel/smm_reloc.h>
#include <cpu/amd/amd64_save_state.h>
#include <mainboard/emulation/qemu-i440fx/fw_cfg.h>
 
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");
 
        smm_subregion(SMM_SUBREGION_HANDLER, perm_smbase, perm_smsize);
 
        /* FIXME: on X86_64 the save state size is smaller than the size of the SMM stub */
        *smm_save_state_size = sizeof(amd64_smm_state_save_area_t);
        printk(BIOS_DEBUG, "Save state size: 0x%zx bytes\n", *smm_save_state_size);
}
 
/*
 * 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.
 */
static void relocation_handler(int cpu, uintptr_t curr_smbase,
                               uintptr_t staggered_smbase)
{
        /* The em64t101 save state is sufficiently compatible with older
           save states with regards of smbase, smm_revision. */
        amd64_smm_state_save_area_t *save_state;
        u32 smbase = staggered_smbase;
 
        save_state = (void *)(curr_smbase + SMM_DEFAULT_SIZE - sizeof(*save_state));
        save_state->smbase = smbase;
 
        printk(BIOS_DEBUG, "In relocation handler: cpu %d\n", cpu);
        printk(BIOS_DEBUG, "SMM revision: 0x%08x\n", save_state->smm_revision);
        printk(BIOS_DEBUG, "New SMBASE=0x%08x\n", smbase);
}
 
static void post_mp_init(void)
{
        /* Now that all APs have been relocated as well as the BSP let SMIs start flowing. */
        global_smi_enable();
 
        /* Lock down the SMRAM space. */
        smm_lock();
}
 
const struct mp_ops mp_ops_with_smm = {
        .get_cpu_count       = fw_cfg_max_cpus,
        .get_smm_info        = get_smm_info,
        .pre_mp_smm_init     = smm_southbridge_clear_state,
        .relocation_handler  = relocation_handler,
        .post_mp_init        = post_mp_init,
};