smi_util.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
/*
 * SMM utilities used in both SMM and normal mode
 */
 
#include <amdblocks/acpimmio.h>
#include <console/console.h>
 
#include "smi.h"
 
#define HUDSON_SMI_ACPI_COMMAND         75
 
static void configure_smi(uint8_t smi_num, uint8_t mode)
{
        uint8_t reg32_offset, bit_offset;
        uint32_t reg32;
 
        /* SMI sources range from [0:149] */
        if (smi_num > 149) {
                printk(BIOS_WARNING, "BUG: Invalid SMI: %u\n", smi_num);
                return;
        }
 
        /* 16 sources per register, 2 bits per source; registers are 4 bytes */
        reg32_offset = (smi_num / 16) * 4;
        bit_offset = (smi_num % 16) * 2;
 
        reg32 = smi_read32(SMI_REG_CONTROL0 + reg32_offset);
        reg32 &= ~(0x3 << (bit_offset));
        reg32 |= (mode & 0x3) << bit_offset;
        smi_write32(SMI_REG_CONTROL0 + reg32_offset, reg32);
}
 
/**
 * Configure generation of interrupts for given GEVENT pin
 *
 * @param gevent The GEVENT pin number. Valid values are 0 thru 23
 * @param mode The type of event this pin should generate. Note that only
 *             SMI_MODE_SMI generates an SMI. SMI_MODE_DISABLE disables events.
 * @param level SMI_LVL_LOW or SMI_LVL_HIGH
 */
void hudson_configure_gevent_smi(uint8_t gevent, uint8_t mode, uint8_t level)
{
        uint32_t reg32;
        /* GEVENT pins range from [0:23] */
        if (gevent > 23) {
                printk(BIOS_WARNING, "BUG: Invalid GEVENT: %u\n", gevent);
                return;
        }
 
        /* SMI0 source is GEVENT0 and so on */
        configure_smi(gevent, mode);
 
        /* And set the trigger level */
        reg32 = smi_read32(SMI_REG_SMITRIG0);
        reg32 &= ~(1 << gevent);
        reg32 |= (level & 0x1) << gevent;
        smi_write32(SMI_REG_SMITRIG0, reg32);
}
 
/** Disable events from given GEVENT pin */
void hudson_disable_gevent_smi(uint8_t gevent)
{
        /* GEVENT pins range from [0:23] */
        if (gevent > 23) {
                printk(BIOS_WARNING, "BUG: Invalid GEVENT: %u\n", gevent);
                return;
        }
 
        /* SMI0 source is GEVENT0 and so on */
        configure_smi(gevent, SMI_MODE_DISABLE);
}
 
/** Enable SMIs on writes to ACPI SMI command port */
void hudson_enable_acpi_cmd_smi(void)
{
        configure_smi(HUDSON_SMI_ACPI_COMMAND, SMI_MODE_SMI);
}