smi_apmc_helper.c

Go to the documentation of this file.

/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <amdblocks/smm.h>
#include <cpu/amd/amd64_save_state.h>
#include <cpu/x86/smm.h>
#include <elog.h>
#include <smmstore.h>
#include <types.h>
 
/* bits in smm_io_trap   */
#define SMM_IO_TRAP_PORT_OFFSET         16
#define SMM_IO_TRAP_PORT_ADDRESS_MASK   0xffff
#define SMM_IO_TRAP_RW                  (1 << 0)
#define SMM_IO_TRAP_VALID               (1 << 1)
 
static inline u16 get_io_address(u32 info)
{
        return ((info >> SMM_IO_TRAP_PORT_OFFSET) &
                SMM_IO_TRAP_PORT_ADDRESS_MASK);
}
 
static void *find_save_state(int cmd)
{
        unsigned int core;
        amd64_smm_state_save_area_t *state;
        u32 smm_io_trap;
        u8 reg_al;
 
        /* Check all nodes looking for the one that issued the IO */
        for (core = 0; core < CONFIG_MAX_CPUS; core++) {
                state = smm_get_save_state(core);
                smm_io_trap = state->smm_io_trap_offset;
                /* Check for Valid IO Trap Word (bit1==1) */
                if (!(smm_io_trap & SMM_IO_TRAP_VALID))
                        continue;
                /* Make sure it was a write (bit0==0) */
                if (smm_io_trap & SMM_IO_TRAP_RW)
                        continue;
                /* Check for APMC IO port */
                if (pm_acpi_smi_cmd_port() != get_io_address(smm_io_trap))
                        continue;
                /* Check AL against the requested command */
                reg_al = state->rax;
                if (reg_al == cmd)
                        return state;
        }
        return NULL;
}
 
void handle_smi_gsmi(void)
{
        u8 sub_command;
        amd64_smm_state_save_area_t *io_smi;
        u32 reg_ebx;
 
        io_smi = find_save_state(APM_CNT_ELOG_GSMI);
        if (!io_smi)
                return;
        /* Command and return value in EAX */
        sub_command = (io_smi->rax >> 8) & 0xff;
 
        /* Parameter buffer in EBX */
        reg_ebx = io_smi->rbx;
 
        /* drivers/elog/gsmi.c */
        io_smi->rax = gsmi_exec(sub_command, &reg_ebx);
}
 
void handle_smi_store(void)
{
        u8 sub_command;
        amd64_smm_state_save_area_t *io_smi;
        u32 reg_ebx;
 
        io_smi = find_save_state(APM_CNT_SMMSTORE);
        if (!io_smi)
                return;
        /* Command and return value in EAX */
        sub_command = (io_smi->rax >> 8) & 0xff;
 
        /* Parameter buffer in EBX */
        reg_ebx = io_smi->rbx;
 
        /* drivers/smmstore/smi.c */
        io_smi->rax = smmstore_exec(sub_command, (void *)reg_ebx);
}