smihandler.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <arch/hlt.h>
#include <arch/io.h>
#include <console/console.h>
#include <cpu/x86/cache.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/smm.h>
#include <cpu/intel/em64t100_save_state.h>
#include <cpu/intel/em64t101_save_state.h>
#include <cpu/intel/msr.h>
#include <delay.h>
#include <device/mmio.h>
#include <device/pci_def.h>
#include <device/pci_ops.h>
#include <elog.h>
#include <intelblocks/fast_spi.h>
#include <intelblocks/pmclib.h>
#include <intelblocks/smihandler.h>
#include <intelblocks/tco.h>
#include <intelblocks/uart.h>
#include <smmstore.h>
#include <soc/nvs.h>
#include <soc/pci_devs.h>
#include <soc/pm.h>
#include <soc/gpio.h>
#include <soc/iomap.h>
#include <soc/smbus.h>
#include <spi-generic.h>
#include <stdint.h>
 
/* SoC overrides. */
 
__weak const struct smm_save_state_ops *get_smm_save_state_ops(void)
{
        return &em64t101_smm_ops;
}
 
/* Specific SOC SMI handler during ramstage finalize phase */
__weak void smihandler_soc_at_finalize(void)
{
        return;
}
 
__weak int smihandler_soc_disable_busmaster(pci_devfn_t dev)
{
        return 1;
}
 
/* Mainboard overrides. */
 
__weak void mainboard_smi_gpi_handler(
        const struct gpi_status *sts)
{
        return;
}
 
__weak void mainboard_smi_espi_handler(void)
{
        return;
}
 
/* Common Functions */
 
static void *find_save_state(const struct smm_save_state_ops *save_state_ops,
        int cmd)
{
        int node;
        void *state = NULL;
        uint32_t io_misc_info;
        uint8_t reg_al;
 
        /* Check all nodes looking for the one that issued the IO */
        for (node = 0; node < CONFIG_MAX_CPUS; node++) {
                state = smm_get_save_state(node);
 
                io_misc_info = save_state_ops->get_io_misc_info(state);
 
                /* Check for Synchronous IO (bit0==1) */
                if (!(io_misc_info & (1 << 0)))
                        continue;
                /* Make sure it was a write (bit4==0) */
                if (io_misc_info & (1 << 4))
                        continue;
                /* Check for APMC IO port */
                if (((io_misc_info >> 16) & 0xff) != APM_CNT)
                        continue;
                /* Check AL against the requested command */
                reg_al = save_state_ops->get_reg(state, RAX);
                if (reg_al != cmd)
                        continue;
                break;
        }
        return state;
}
 
/* Inherited from cpu/x86/smm.h resulting in a different signature */
void southbridge_smi_set_eos(void)
{
        pmc_enable_smi(EOS);
}
 
static void busmaster_disable_on_bus(int bus)
{
        int slot, func;
        unsigned int val;
        unsigned char hdr;
 
        for (slot = 0; slot < 0x20; slot++) {
                for (func = 0; func < 8; func++) {
                        u16 reg16;
 
                        pci_devfn_t dev = PCI_DEV(bus, slot, func);
 
                        if (!smihandler_soc_disable_busmaster(dev))
                                continue;
                        val = pci_read_config32(dev, PCI_VENDOR_ID);
 
                        if (val == 0xffffffff || val == 0x00000000 ||
                            val == 0x0000ffff || val == 0xffff0000)
                                continue;
 
                        /* Disable Bus Mastering for this one device */
                        reg16 = pci_read_config16(dev, PCI_COMMAND);
                        reg16 &= ~PCI_COMMAND_MASTER;
                        pci_write_config16(dev, PCI_COMMAND, reg16);
 
                        /* If it's not a bridge, move on. */
                        hdr = pci_read_config8(dev, PCI_HEADER_TYPE);
                        hdr &= 0x7f;
                        if (hdr != PCI_HEADER_TYPE_BRIDGE &&
                            hdr != PCI_HEADER_TYPE_CARDBUS)
                                continue;
 
                        /*
                         * If secondary bus is equal to current bus bypass
                         * the bridge because it's likely unconfigured and
                         * would cause infinite recursion.
                         */
                        int secbus = pci_read_config8(dev, PCI_SECONDARY_BUS);
 
                        if (secbus == bus)
                                continue;
 
                        busmaster_disable_on_bus(secbus);
                }
        }
}
 
void smihandler_southbridge_sleep(
        const struct smm_save_state_ops *save_state_ops)
{
        uint32_t reg32;
        uint8_t slp_typ;
 
        /* First, disable further SMIs */
        pmc_disable_smi(SLP_SMI_EN);
        /* Figure out SLP_TYP */
        reg32 = inl(ACPI_BASE_ADDRESS + PM1_CNT);
        printk(BIOS_SPEW, "SMI#: SLP = 0x%08x\n", reg32);
        slp_typ = acpi_sleep_from_pm1(reg32);
 
        /* Do any mainboard sleep handling */
        mainboard_smi_sleep(slp_typ);
 
        /* Log S3, S4, and S5 entry */
        if (slp_typ >= ACPI_S3)
                elog_gsmi_add_event_byte(ELOG_TYPE_ACPI_ENTER, slp_typ);
 
        /* Clear pending GPE events */
        pmc_clear_all_gpe_status();
 
        /* Next, do the deed. */
 
        switch (slp_typ) {
        case ACPI_S0:
                printk(BIOS_DEBUG, "SMI#: Entering S0 (On)\n");
                break;
        case ACPI_S3:
                printk(BIOS_DEBUG, "SMI#: Entering S3 (Suspend-To-RAM)\n");
                if (CONFIG(SOC_INTEL_COMMON_BLOCK_UART))
                        gnvs->uior = uart_is_controller_initialized();
 
                /* Invalidate the cache before going to S3 */
                wbinvd();
                break;
        case ACPI_S4:
                printk(BIOS_DEBUG, "SMI#: Entering S4 (Suspend-To-Disk)\n");
                break;
        case ACPI_S5:
                printk(BIOS_DEBUG, "SMI#: Entering S5 (Soft Power off)\n");
 
                /* Disable all GPE */
                pmc_disable_all_gpe();
                /* Set which state system will be after power reapplied */
                pmc_set_power_failure_state(false);
                /* also iterates over all bridges on bus 0 */
                busmaster_disable_on_bus(0);
 
                /*
                 * Some platforms (e.g. Chromebooks) have observed race between
                 * SLP SMI and PWRBTN SMI because of the way these SMIs are
                 * triggered on power button press. Allow adding a delay before
                 * triggering sleep enable for S5, so that power button
                 * interrupt does not result into immediate wake.
                 */
                mdelay(CONFIG_SOC_INTEL_COMMON_BLOCK_SMM_S5_DELAY_MS);
 
                /*
                 * Ensure any pending power button status bits are cleared as
                 * the system is entering S5 and doesn't want to be woken up
                 * right away from older power button events.
                 */
                pmc_clear_pm1_status();
 
                break;
        default:
                printk(BIOS_DEBUG, "SMI#: ERROR: SLP_TYP reserved\n");
                break;
        }
 
        /*
         * Write back to the SLP register to cause the originally intended
         * event again. We need to set BIT13 (SLP_EN) though to make the
         * sleep happen.
         */
        pmc_enable_pm1_control(SLP_EN);
 
        /* Make sure to stop executing code here for S3/S4/S5 */
        if (slp_typ >= ACPI_S3)
                hlt();
 
        /*
         * In most sleep states, the code flow of this function ends at
         * the line above. However, if we entered sleep state S1 and wake
         * up again, we will continue to execute code in this function.
         */
        if (pmc_read_pm1_control() & SCI_EN) {
                /* The OS is not an ACPI OS, so we set the state to S0 */
                pmc_disable_pm1_control(SLP_EN | SLP_TYP);
        }
}
 
static void southbridge_smi_gsmi(
        const struct smm_save_state_ops *save_state_ops)
{
        u8 sub_command, ret;
        void *io_smi = NULL;
        uint32_t reg_ebx;
 
        io_smi = find_save_state(save_state_ops, APM_CNT_ELOG_GSMI);
        if (!io_smi)
                return;
        /* Command and return value in EAX */
        sub_command = (save_state_ops->get_reg(io_smi, RAX) >> 8)
                & 0xff;
 
        /* Parameter buffer in EBX */
        reg_ebx = save_state_ops->get_reg(io_smi, RBX);
 
        /* drivers/elog/gsmi.c */
        ret = gsmi_exec(sub_command, &reg_ebx);
        save_state_ops->set_reg(io_smi, RAX, ret);
}
 
static void set_insmm_sts(const bool enable_writes)
{
        msr_t msr = {
                .lo = read32p(0xfed30880),
                .hi = 0,
        };
        if (enable_writes)
                msr.lo |= 1;
        else
                msr.lo &= ~1;
 
        wrmsr(MSR_SPCL_CHIPSET_USAGE, msr);
}
 
static void southbridge_smi_store(
        const struct smm_save_state_ops *save_state_ops)
{
        u8 sub_command, ret;
        void *io_smi;
        uint32_t reg_ebx;
 
        io_smi = find_save_state(save_state_ops, APM_CNT_SMMSTORE);
        if (!io_smi)
                return;
        /* Command and return value in EAX */
        sub_command = (save_state_ops->get_reg(io_smi, RAX) >> 8) & 0xff;
 
        /* Parameter buffer in EBX */
        reg_ebx = save_state_ops->get_reg(io_smi, RBX);
 
        const bool wp_enabled = !fast_spi_wpd_status();
        if (wp_enabled) {
                set_insmm_sts(true);
                fast_spi_disable_wp();
                /* Not clearing SPI sync SMI status here results in hangs */
                fast_spi_clear_sync_smi_status();
        }
 
        /* drivers/smmstore/smi.c */
        ret = smmstore_exec(sub_command, (void *)(uintptr_t)reg_ebx);
        save_state_ops->set_reg(io_smi, RAX, ret);
 
        if (wp_enabled) {
                fast_spi_enable_wp();
                set_insmm_sts(false);
        }
}
 
__weak const struct gpio_lock_config *soc_gpio_lock_config(size_t *num)
{
        *num = 0;
        return NULL;
}
 
static void soc_lock_gpios(void)
{
        const struct gpio_lock_config *soc_gpios;
        size_t soc_gpio_num;
 
        /* get list of gpios from SoC */
        soc_gpios = soc_gpio_lock_config(&soc_gpio_num);
 
        /* Lock any soc requested gpios */
        if (soc_gpio_num)
                gpio_lock_pads(soc_gpios, soc_gpio_num);
}
 
static void finalize(void)
{
        static int finalize_done;
 
        if (finalize_done) {
                printk(BIOS_DEBUG, "SMM already finalized.\n");
                return;
        }
        finalize_done = 1;
 
        if (CONFIG(SPI_FLASH_SMM))
                /* Re-init SPI driver to handle locked BAR */
                fast_spi_init();
 
        if (CONFIG(BOOTMEDIA_SMM_BWP)) {
                fast_spi_enable_wp();
                set_insmm_sts(false);
        }
 
        /*
         * HECI is disabled in smihandler_soc_at_finalize() which also locks down the side band
         * interface.  Some boards may require this interface in mainboard_smi_finalize(),
         * therefore, this call must precede smihandler_soc_at_finalize().
         */
        mainboard_smi_finalize();
 
        /* Lock down all GPIOs that may have been requested by the SoC and/or the mainboard. */
        if (CONFIG(SOC_INTEL_COMMON_BLOCK_SMM_LOCK_GPIO_PADS))
                soc_lock_gpios();
 
        /* Specific SOC SMI handler during ramstage finalize phase */
        smihandler_soc_at_finalize();
}
 
void smihandler_southbridge_apmc(
        const struct smm_save_state_ops *save_state_ops)
{
        uint8_t reg8;
 
        reg8 = apm_get_apmc();
        switch (reg8) {
        case APM_CNT_ACPI_DISABLE:
                pmc_disable_pm1_control(SCI_EN);
                break;
        case APM_CNT_ACPI_ENABLE:
                pmc_enable_pm1_control(SCI_EN);
                break;
        case APM_CNT_ELOG_GSMI:
                if (CONFIG(ELOG_GSMI))
                        southbridge_smi_gsmi(save_state_ops);
                break;
        case APM_CNT_SMMSTORE:
                if (CONFIG(SMMSTORE))
                        southbridge_smi_store(save_state_ops);
                break;
        case APM_CNT_FINALIZE:
                finalize();
                break;
        }
 
        mainboard_smi_apmc(reg8);
}
 
void smihandler_southbridge_pm1(
        const struct smm_save_state_ops *save_state_ops)
{
        uint16_t pm1_sts = pmc_clear_pm1_status();
        u16 pm1_en = pmc_read_pm1_enable();
 
        /*
         * While OSPM is not active, poweroff immediately
         * on a power button event.
         */
        if ((pm1_sts & PWRBTN_STS) && (pm1_en & PWRBTN_EN)) {
                /* power button pressed */
                elog_gsmi_add_event(ELOG_TYPE_POWER_BUTTON);
                pmc_disable_pm1_control(~0);
                pmc_enable_pm1_control(SLP_EN | (SLP_TYP_S5 << SLP_TYP_SHIFT));
        }
}
 
void smihandler_southbridge_gpe0(
        const struct smm_save_state_ops *save_state_ops)
{
        pmc_clear_all_gpe_status();
}
 
void smihandler_southbridge_tco(
        const struct smm_save_state_ops *save_state_ops)
{
        uint32_t tco_sts = pmc_clear_tco_status();
 
        /*
         * SPI synchronous SMIs are TCO SMIs, but they do not have a status
         * bit in the TCO_STS register. Furthermore, the TCO_STS bit in the
         * SMI_STS register is continually set until the SMI handler clears
         * the SPI synchronous SMI status bit in the SPI controller. To not
         * risk missing any other TCO SMIs, do not clear the TCO_STS bit in
         * this SMI handler invocation. If the TCO_STS bit remains set when
         * returning from SMM, another SMI immediately happens which clears
         * the TCO_STS bit and handles any pending events.
         */
        fast_spi_clear_sync_smi_status();
 
        /* If enabled, enforce SMM BIOS write protection */
        if (CONFIG(BOOTMEDIA_SMM_BWP) && fast_spi_wpd_status()) {
                /*
                 * BWE is RW, so the SMI was caused by a
                 * write to BWE, not by a write to the BIOS
                 *
                 * This is the place where we notice someone
                 * is trying to tinker with the BIOS. We are
                 * trying to be nice and just ignore it. A more
                 * resolute answer would be to power down the
                 * box.
                 */
                printk(BIOS_DEBUG, "Switching SPI back to RO\n");
                fast_spi_enable_wp();
                set_insmm_sts(false);
        }
 
        /* Any TCO event? */
        if (!tco_sts)
                return;
 
        if (tco_sts & TCO_TIMEOUT) { /* TIMEOUT */
                /* Handle TCO timeout */
                printk(BIOS_DEBUG, "TCO Timeout.\n");
        }
 
        if (tco_sts & (TCO_INTRD_DET << 16)) { /* INTRUDER# assertion */
                /*
                 * Handle intrusion event
                 * If we ever get here, probably the case has been opened.
                 */
                printk(BIOS_CRIT, "Case intrusion detected.\n");
        }
}
 
void smihandler_southbridge_periodic(
        const struct smm_save_state_ops *save_state_ops)
{
        uint32_t reg32;
 
        reg32 = pmc_get_smi_en();
 
        /* Are periodic SMIs enabled? */
        if ((reg32 & PERIODIC_EN) == 0)
                return;
        printk(BIOS_DEBUG, "Periodic SMI.\n");
}
 
void smihandler_southbridge_gpi(
        const struct smm_save_state_ops *save_state_ops)
{
        struct gpi_status smi_sts;
 
        gpi_clear_get_smi_status(&smi_sts);
        mainboard_smi_gpi_handler(&smi_sts);
 
        /* Clear again after mainboard handler */
        gpi_clear_get_smi_status(&smi_sts);
}
 
void smihandler_southbridge_espi(
        const struct smm_save_state_ops *save_state_ops)
{
        mainboard_smi_espi_handler();
}
 
void southbridge_smi_handler(void)
{
        int i;
        uint32_t smi_sts;
        const struct smm_save_state_ops *save_state_ops;
 
        /*
         * We need to clear the SMI status registers, or we won't see what's
         * happening in the following calls.
         */
        smi_sts = pmc_clear_smi_status();
 
        /*
         * When the SCI_EN bit is set, PM1 and GPE0 events will trigger a SCI
         * instead of a SMI#. However, SMI_STS bits PM1_STS and GPE0_STS can
         * still be set. Therefore, when SCI_EN is set, ignore PM1 and GPE0
         * events in the SMI# handler, as these events have triggered a SCI.
         * Do not ignore any other SMI# types, since they cannot cause a SCI.
         */
        if (pmc_read_pm1_control() & SCI_EN)
                smi_sts &= ~(1 << PM1_STS_BIT | 1 << GPE0_STS_BIT);
 
        if (!smi_sts)
                return;
 
        save_state_ops = get_smm_save_state_ops();
 
        /* Call SMI sub handler for each of the status bits */
        for (i = 0; i < ARRAY_SIZE(southbridge_smi); i++) {
                if (!(smi_sts & (1 << i)))
                        continue;
 
                if (southbridge_smi[i] != NULL) {
                        southbridge_smi[i](save_state_ops);
                } else {
                        printk(BIOS_DEBUG,
                               "SMI_STS[%d] occurred, but no "
                               "handler available.\n", i);
                }
        }
}
 
static uint32_t em64t100_smm_save_state_get_io_misc_info(void *state)
{
        em64t100_smm_state_save_area_t *smm_state = state;
        return smm_state->io_misc_info;
}
 
static uint64_t em64t100_smm_save_state_get_reg(void *state, enum smm_reg reg)
{
        uintptr_t value = 0;
        em64t100_smm_state_save_area_t *smm_state = state;
 
        switch (reg) {
        case RAX:
                value = smm_state->rax;
                break;
        case RBX:
                value = smm_state->rbx;
                break;
        case RCX:
                value = smm_state->rcx;
                break;
        case RDX:
                value = smm_state->rdx;
                break;
        default:
                break;
        }
        return value;
}
 
static void em64t100_smm_save_state_set_reg(void *state, enum smm_reg reg,
        uint64_t val)
{
        em64t100_smm_state_save_area_t *smm_state = state;
        switch (reg) {
        case RAX:
                smm_state->rax = val;
                break;
        case RBX:
                smm_state->rbx = val;
                break;
        case RCX:
                smm_state->rcx = val;
                break;
        case RDX:
                smm_state->rdx = val;
                break;
        default:
                break;
        }
}
 
static uint32_t em64t101_smm_save_state_get_io_misc_info(void *state)
{
        em64t101_smm_state_save_area_t *smm_state = state;
        return smm_state->io_misc_info;
}
 
static uint64_t em64t101_smm_save_state_get_reg(void *state, enum smm_reg reg)
{
        uintptr_t value = 0;
        em64t101_smm_state_save_area_t *smm_state = state;
 
        switch (reg) {
        case RAX:
                value = smm_state->rax;
                break;
        case RBX:
                value = smm_state->rbx;
                break;
        case RCX:
                value = smm_state->rcx;
                break;
        case RDX:
                value = smm_state->rdx;
                break;
        default:
                break;
        }
        return value;
}
 
static void em64t101_smm_save_state_set_reg(void *state, enum smm_reg reg,
        uint64_t val)
{
        em64t101_smm_state_save_area_t *smm_state = state;
        switch (reg) {
        case RAX:
                smm_state->rax = val;
                break;
        case RBX:
                smm_state->rbx = val;
                break;
        case RCX:
                smm_state->rcx = val;
                break;
        case RDX:
                smm_state->rdx = val;
                break;
        default:
                break;
        }
}
 
const struct smm_save_state_ops em64t100_smm_ops = {
        .get_io_misc_info = em64t100_smm_save_state_get_io_misc_info,
        .get_reg = em64t100_smm_save_state_get_reg,
        .set_reg = em64t100_smm_save_state_set_reg,
};
 
const struct smm_save_state_ops em64t101_smm_ops = {
        .get_io_misc_info = em64t101_smm_save_state_get_io_misc_info,
        .get_reg = em64t101_smm_save_state_get_reg,
        .set_reg = em64t101_smm_save_state_set_reg,
};