src/soc/intel/broadwell/smihandler.c

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

#include <delay.h>
#include <types.h>
#include <arch/io.h>
#include <device/mmio.h>
#include <device/pci_ops.h>
#include <console/console.h>
#include <cpu/x86/cache.h>
#include <device/pci_def.h>
#include <cpu/x86/smm.h>
#include <cpu/intel/em64t101_save_state.h>
#include <spi-generic.h>
#include <elog.h>
#include <halt.h>
#include <option.h>
#include <soc/lpc.h>
#include <soc/nvs.h>
#include <soc/pci_devs.h>
#include <soc/pm.h>
#include <soc/rcba.h>
#include <soc/xhci.h>
#include <drivers/intel/gma/i915_reg.h>
#include <smmstore.h>

static u8 smm_initialized = 0;

int southbridge_io_trap_handler(int smif)
{
	switch (smif) {
	case 0x32:
		printk(BIOS_DEBUG, "OS Init\n");
		/* gnvs->smif:
		 *  On success, the IO Trap Handler returns 0
		 *  On failure, the IO Trap Handler returns a value != 0
		 */
		gnvs->smif = 0;
		return 1; /* IO trap handled */
	}

	/* Not handled */
	return 0;
}

/**
 * @brief Set the EOS bit
 */
void southbridge_smi_set_eos(void)
{
	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++) {
			pci_devfn_t dev = PCI_DEV(bus, slot, func);

			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 */
			pci_and_config16(dev, PCI_COMMAND, ~PCI_COMMAND_MASTER);

			/* If this is a bridge, then follow it. */
			hdr = pci_read_config8(dev, PCI_HEADER_TYPE);
			hdr &= 0x7f;
			if (hdr == PCI_HEADER_TYPE_BRIDGE ||
			    hdr == PCI_HEADER_TYPE_CARDBUS) {
				unsigned int buses;
				buses = pci_read_config32(dev, PCI_PRIMARY_BUS);
				busmaster_disable_on_bus((buses >> 8) & 0xff);
			}
		}
	}
}

/*
 * Turn off the backlight if it is on, and wait for the specified
 * backlight off delay.  This will allow panel power timings to meet
 * spec and prevent brief garbage on the screen when turned off
 * during firmware with power button triggered SMI.
 */
static void backlight_off(void)
{
	void *reg_base;
	uint32_t pp_ctrl;
	uint32_t bl_off_delay;

	reg_base = (void *)((uintptr_t)pci_read_config32(SA_DEV_IGD,
		PCI_BASE_ADDRESS_0) & ~0xf);

	/* Validate pointer before using it */
	if (smm_points_to_smram(reg_base, PCH_PP_OFF_DELAYS + sizeof(uint32_t)))
		return;

	/* Check if backlight is enabled */
	pp_ctrl = read32(reg_base + PCH_PP_CONTROL);
	if (!(pp_ctrl & EDP_BLC_ENABLE))
		return;

	/* Enable writes to this register */
	pp_ctrl &= ~PANEL_UNLOCK_MASK;
	pp_ctrl |= PANEL_UNLOCK_REGS;

	/* Turn off backlight */
	pp_ctrl &= ~EDP_BLC_ENABLE;

	write32(reg_base + PCH_PP_CONTROL, pp_ctrl);
	read32(reg_base + PCH_PP_CONTROL);

	/* Read backlight off delay in 100us units */
	bl_off_delay = read32(reg_base + PCH_PP_OFF_DELAYS);
	bl_off_delay &= PANEL_LIGHT_OFF_DELAY_MASK;
	bl_off_delay *= 100;

	/* Wait for backlight to turn off */
	udelay(bl_off_delay);

	printk(BIOS_INFO, "Backlight turned off\n");
}

static void southbridge_smi_sleep(void)
{
	u8 reg8;
	u32 reg32;
	u8 slp_typ;
	u8 s5pwr = CONFIG_MAINBOARD_POWER_FAILURE_STATE;
	u16 pmbase = get_pmbase();

	/* save and recover RTC port values */
	u8 tmp70, tmp72;
	tmp70 = inb(0x70);
	tmp72 = inb(0x72);
	get_option(&s5pwr, "power_on_after_fail");
	outb(tmp70, 0x70);
	outb(tmp72, 0x72);

	/* First, disable further SMIs */
	disable_smi(SLP_SMI_EN);

	/* Figure out SLP_TYP */
	reg32 = inl(pmbase + 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);

	/* USB sleep preparations */
	usb_xhci_sleep_prepare(PCH_DEV_XHCI, 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 */
	clear_gpe_status();

	/* Next, do the deed.
	 */

	switch (slp_typ) {
	case ACPI_S0:
		printk(BIOS_DEBUG, "SMI#: Entering S0 (On)\n");
		break;
	case ACPI_S1:
		printk(BIOS_DEBUG, "SMI#: Entering S1 (Assert STPCLK#)\n");
		break;
	case ACPI_S3:
		printk(BIOS_DEBUG, "SMI#: Entering S3 (Suspend-To-RAM)\n");

		/* 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");

		/* Turn off backlight if needed */
		backlight_off();

		/* Disable all GPE */
		disable_all_gpe();

		/* Always set the flag in case CMOS was changed on runtime. For
		 * "KEEP", switch to "OFF" - KEEP is software emulated
		 */
		reg8 = pci_read_config8(PCH_DEV_LPC, GEN_PMCON_3);
		if (s5pwr == MAINBOARD_POWER_ON)
			reg8 &= ~1;
		else
			reg8 |= 1;
		pci_write_config8(PCH_DEV_LPC, GEN_PMCON_3, reg8);

		/* also iterates over all bridges on bus 0 */
		busmaster_disable_on_bus(0);
		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.
	 */
	enable_pm1_control(SLP_EN);

	/* Make sure to stop executing code here for S3/S4/S5 */
	if (slp_typ >= ACPI_S3)
		halt();

	/*
	 * 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.
	 */
	reg32 = inl(pmbase + PM1_CNT);
	if (reg32 & SCI_EN) {
		/* The OS is not an ACPI OS, so we set the state to S0 */
		disable_pm1_control(SLP_EN | SLP_TYP);
	}
}

/*
 * Look for Synchronous IO SMI and use save state from that
 * core in case we are not running on the same core that
 * initiated the IO transaction.
 */
static em64t101_smm_state_save_area_t *smi_apmc_find_state_save(u8 cmd)
{
	em64t101_smm_state_save_area_t *state;
	int node;

	/* 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);

		/* Check for Synchronous IO (bit0 == 1) */
		if (!(state->io_misc_info & (1 << 0)))
			continue;

		/* Make sure it was a write (bit4 == 0) */
		if (state->io_misc_info & (1 << 4))
			continue;

		/* Check for APMC IO port */
		if (((state->io_misc_info >> 16) & 0xff) != APM_CNT)
			continue;

		/* Check AX against the requested command */
		if ((state->rax & 0xff) != cmd)
			continue;

		return state;
	}

	return NULL;
}

static void southbridge_smi_gsmi(void)
{
	u32 *ret, *param;
	u8 sub_command;
	em64t101_smm_state_save_area_t *io_smi =
		smi_apmc_find_state_save(APM_CNT_ELOG_GSMI);

	if (!io_smi)
		return;

	/* Command and return value in EAX */
	ret = (u32 *)&io_smi->rax;
	sub_command = (u8)(*ret >> 8);

	/* Parameter buffer in EBX */
	param = (u32 *)&io_smi->rbx;

	/* drivers/elog/gsmi.c */
	*ret = gsmi_exec(sub_command, param);
}

static void southbridge_smi_store(void)
{
	u8 sub_command, ret;
	em64t101_smm_state_save_area_t *io_smi =
		smi_apmc_find_state_save(APM_CNT_SMMSTORE);
	uint32_t reg_ebx;

	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 */
	ret = smmstore_exec(sub_command, (void *)reg_ebx);
	io_smi->rax = ret;
}

static void southbridge_smi_apmc(void)
{
	u8 reg8;
	em64t101_smm_state_save_area_t *state;

	/* Emulate B2 register as the FADT / Linux expects it */

	reg8 = inb(APM_CNT);
	switch (reg8) {
	case APM_CNT_CST_CONTROL:
		printk(BIOS_DEBUG, "C-state control\n");
		break;
	case APM_CNT_PST_CONTROL:
		printk(BIOS_DEBUG, "P-state control\n");
		break;
	case APM_CNT_ACPI_DISABLE:
		disable_pm1_control(SCI_EN);
		printk(BIOS_DEBUG, "SMI#: ACPI disabled.\n");
		break;
	case APM_CNT_ACPI_ENABLE:
		enable_pm1_control(SCI_EN);
		printk(BIOS_DEBUG, "SMI#: ACPI enabled.\n");
		break;
	case APM_CNT_GNVS_UPDATE:
		if (smm_initialized) {
			printk(BIOS_DEBUG,
			       "SMI#: SMM structures already initialized!\n");
			return;
		}
		state = smi_apmc_find_state_save(reg8);
		if (state) {
			/* EBX in the state save contains the GNVS pointer */
			gnvs = (struct global_nvs *)((u32)state->rbx);
			if (smm_points_to_smram(gnvs, sizeof(*gnvs))) {
				printk(BIOS_ERR, "SMI#: ERROR: GNVS overlaps SMM\n");
				return;
			}
			smm_initialized = 1;
			printk(BIOS_DEBUG, "SMI#: Setting GNVS to %p\n", gnvs);
		}
		break;
	case APM_CNT_ELOG_GSMI:
		if (CONFIG(ELOG_GSMI))
			southbridge_smi_gsmi();
		break;
	case APM_CNT_SMMSTORE:
		if (CONFIG(SMMSTORE))
			southbridge_smi_store();
		break;
	}

	mainboard_smi_apmc(reg8);
}

static void southbridge_smi_pm1(void)
{
	u16 pm1_sts = clear_pm1_status();

	/* While OSPM is not active, poweroff immediately
	 * on a power button event.
	 */
	if (pm1_sts & PWRBTN_STS) {
		/* power button pressed */
		elog_gsmi_add_event(ELOG_TYPE_POWER_BUTTON);
		disable_pm1_control(-1UL);
		enable_pm1_control(SLP_EN | (SLP_TYP_S5 << 10));
	}
}

static void southbridge_smi_gpe0(void)
{
	clear_gpe_status();
}

static void southbridge_smi_gpi(void)
{
	mainboard_smi_gpi(clear_alt_smi_status());

	/* Clear again after mainboard handler */
	clear_alt_smi_status();
}

static void southbridge_smi_mc(void)
{
	u32 reg32 = inl(get_pmbase() + SMI_EN);

	/* Are microcontroller SMIs enabled? */
	if ((reg32 & MCSMI_EN) == 0)
		return;

	printk(BIOS_DEBUG, "Microcontroller SMI.\n");
}

static void southbridge_smi_tco(void)
{
	u32 tco_sts = clear_tco_status();

	/* Any TCO event? */
	if (!tco_sts)
		return;

	// BIOSWR
	if (tco_sts & (1 << 8)) {
		u8 bios_cntl = pci_read_config16(PCH_DEV_LPC, BIOS_CNTL);

		if (bios_cntl & 1) {
			/*
			 * 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 back to RO\n");
			pci_write_config32(PCH_DEV_LPC, BIOS_CNTL,  (bios_cntl & ~1));
		} /* No else for now? */
	} else if (tco_sts & (1 << 3)) { /* TIMEOUT */
		/* Handle TCO timeout */
		printk(BIOS_DEBUG, "TCO Timeout.\n");
	}
}

static void southbridge_smi_periodic(void)
{
	u32 reg32 = inl(get_pmbase() + SMI_EN);

	/* Are periodic SMIs enabled? */
	if ((reg32 & PERIODIC_EN) == 0)
		return;

	printk(BIOS_DEBUG, "Periodic SMI.\n");
}

static void southbridge_smi_monitor(void)
{
#define IOTRAP(x) (trap_sts & (1 << x))
	u32 trap_sts, trap_cycle;
	u32 mask = 0;
	int i;

	trap_sts = RCBA32(0x1e00); // TRSR - Trap Status Register
	RCBA32(0x1e00) = trap_sts; // Clear trap(s) in TRSR

	trap_cycle = RCBA32(0x1e10);
	for (i = 16; i < 20; i++) {
		if (trap_cycle & (1 << i))
			mask |= (0xff << ((i - 16) << 2));
	}

	/* IOTRAP(3) SMI function call */
	if (IOTRAP(3)) {
		if (gnvs && gnvs->smif)
			io_trap_handler(gnvs->smif); // call function smif
		return;
	}

	/* IOTRAP(2) currently unused
	 * IOTRAP(1) currently unused */

	/* IOTRAP(0) SMIC */
	if (IOTRAP(0)) {
		// It's a write
		if (!(trap_cycle & (1 << 24))) {
			printk(BIOS_DEBUG, "SMI1 command\n");
			(void)RCBA32(0x1e18);
			// data = RCBA32(0x1e18);
			// data &= mask;
			// if (smi1)
			//	southbridge_smi_command(data);
			// return;
		}
		// Fall through to debug
	}

	printk(BIOS_DEBUG, "  trapped io address = 0x%x\n",
	       trap_cycle & 0xfffc);
	for (i = 0; i < 4; i++)
		if (IOTRAP(i))
			printk(BIOS_DEBUG, "  TRAP = %d\n", i);
	printk(BIOS_DEBUG, "  AHBE = %x\n", (trap_cycle >> 16) & 0xf);
	printk(BIOS_DEBUG, "  MASK = 0x%08x\n", mask);
	printk(BIOS_DEBUG, "  read/write: %s\n",
	       (trap_cycle & (1 << 24)) ? "read" : "write");

	if (!(trap_cycle & (1 << 24))) {
		/* Write Cycle */
		printk(BIOS_DEBUG, "  iotrap written data = 0x%08x\n", RCBA32(0x1e18));
	}
#undef IOTRAP
}

typedef void (*smi_handler_t)(void);

static smi_handler_t southbridge_smi[32] = {
	NULL,			  //  [0] reserved
	NULL,			  //  [1] reserved
	NULL,			  //  [2] BIOS_STS
	NULL,			  //  [3] LEGACY_USB_STS
	southbridge_smi_sleep,	  //  [4] SLP_SMI_STS
	southbridge_smi_apmc,	  //  [5] APM_STS
	NULL,			  //  [6] SWSMI_TMR_STS
	NULL,			  //  [7] reserved
	southbridge_smi_pm1,	  //  [8] PM1_STS
	southbridge_smi_gpe0,	  //  [9] GPE0_STS
	southbridge_smi_gpi,	  // [10] GPI_STS
	southbridge_smi_mc,	  // [11] MCSMI_STS
	NULL,			  // [12] DEVMON_STS
	southbridge_smi_tco,	  // [13] TCO_STS
	southbridge_smi_periodic, // [14] PERIODIC_STS
	NULL,			  // [15] SERIRQ_SMI_STS
	NULL,			  // [16] SMBUS_SMI_STS
	NULL,			  // [17] LEGACY_USB2_STS
	NULL,			  // [18] INTEL_USB2_STS
	NULL,			  // [19] reserved
	NULL,			  // [20] PCI_EXP_SMI_STS
	southbridge_smi_monitor,  // [21] MONITOR_STS
	NULL,			  // [22] reserved
	NULL,			  // [23] reserved
	NULL,			  // [24] reserved
	NULL,			  // [25] EL_SMI_STS
	NULL,			  // [26] SPI_STS
	NULL,			  // [27] reserved
	NULL,			  // [28] reserved
	NULL,			  // [29] reserved
	NULL,			  // [30] reserved
	NULL			  // [31] reserved
};

/**
 * @brief Interrupt handler for SMI#
 */
void southbridge_smi_handler(void)
{
	int i;
	u32 smi_sts;

	/* We need to clear the SMI status registers, or we won't see what's
	 * happening in the following calls.
	 */
	smi_sts = clear_smi_status();

	/* Call SMI sub handler for each of the status bits */
	for (i = 0; i < 31; i++) {
		if (smi_sts & (1 << i)) {
			if (southbridge_smi[i]) {
				southbridge_smi[i]();
			} else {
				printk(BIOS_DEBUG,
				       "SMI_STS[%d] occurred, but no "
				       "handler available.\n", i);
			}
		}
	}
}