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

#include <types.h>
#include <arch/io.h>
#include <device/pci_ops.h>
#include <acpi/acpi.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 <elog.h>
#include <halt.h>
#include <option.h>
#include <southbridge/intel/common/pmbase.h>
#include <smmstore.h>

#include "pmutil.h"

static int smm_initialized = 0;

u16 get_pmbase(void)
{
	return lpc_get_pmbase();
}

void gpi_route_interrupt(u8 gpi, u8 mode)
{
	u32 gpi_rout;
	if (gpi >= 16)
		return;

	alt_gpi_mask(1 << gpi, 0);
	gpe0_mask(1 << (gpi+16), 0);

	gpi_rout = pci_read_config32(PCI_DEV(0, 0x1f, 0), D31F0_GPIO_ROUT);
	gpi_rout &= ~(3 << (2 * gpi));
	gpi_rout |= ((mode & 3) << (2 * gpi));
	pci_write_config32(PCI_DEV(0, 0x1f, 0), D31F0_GPIO_ROUT, gpi_rout);

	if (mode == GPI_IS_SCI)
		gpe0_mask(0, 1 << (gpi+16));
	else if (mode == GPI_IS_SMI)
		alt_gpi_mask(0, 1 << gpi);
}

/**
 * @brief Set the EOS bit
 */
void southbridge_smi_set_eos(void)
{
	write_pmbase8(SMI_EN, read_pmbase8(SMI_EN) | 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);

			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 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);
			}
		}
	}
}

__weak void southbridge_gate_memory_reset(void)
{
}

__weak void southbridge_smm_xhci_sleep(u8 slp_type)
{
}

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

	// 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 */
	write_pmbase8(SMI_EN, read_pmbase8(SMI_EN) & ~SLP_SMI_EN);

	/* Figure out SLP_TYP */
	reg32 = read_pmbase32(PM1_CNT);
	printk(BIOS_SPEW, "SMI#: SLP = 0x%08x\n", reg32);
	slp_typ = acpi_sleep_from_pm1(reg32);

	southbridge_smm_xhci_sleep(slp_typ);

	/* 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);

	/* 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");

		/* Gate memory reset */
		southbridge_gate_memory_reset();

		/* 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");

		write_pmbase32(GPE0_EN, 0);

		/* Always set the flag in case CMOS was changed on runtime. For
		 * "KEEP", switch to "OFF" - KEEP is software emulated
		 */
		reg8 = pci_read_config8(PCI_DEV(0, 0x1f, 0), D31F0_GEN_PMCON_3);
		if (s5pwr == MAINBOARD_POWER_ON) {
			reg8 &= ~1;
		} else {
			reg8 |= 1;
		}
		pci_write_config8(PCI_DEV(0, 0x1f, 0), D31F0_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.
	 */
	write_pmbase32(PM1_CNT, reg32 | 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 = read_pmbase32(PM1_CNT);
	if (reg32 & SCI_EN) {
		/* The OS is not an ACPI OS, so we set the state to S0 */
		reg32 &= ~(SLP_EN | SLP_TYP);
		write_pmbase32(PM1_CNT, reg32);
	}
}

/*
 * 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.
 */
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);
	uintptr_t reg_rbx;

	if (!io_smi)
		return;
	/* Command and return value in EAX */
	sub_command = (io_smi->rax >> 8) & 0xff;

	/* Parameter buffer in EBX */
	reg_rbx = (uintptr_t)io_smi->rbx;

	/* drivers/smmstore/smi.c */
	ret = smmstore_exec(sub_command, (void *)reg_rbx);
	io_smi->rax = ret;
}

static int mainboard_finalized = 0;

static void southbridge_smi_apmc(void)
{
	u8 reg8;

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

	reg8 = inb(APM_CNT);
	switch (reg8) {
	case APM_CNT_CST_CONTROL:
		/* Calling this function seems to cause
		 * some kind of race condition in Linux
		 * and causes a kernel oops
		 */
		printk(BIOS_DEBUG, "C-state control\n");
		break;
	case APM_CNT_PST_CONTROL:
		/* Calling this function seems to cause
		 * some kind of race condition in Linux
		 * and causes a kernel oops
		 */
		printk(BIOS_DEBUG, "P-state control\n");
		break;
	case APM_CNT_ACPI_DISABLE:
		write_pmbase32(PM1_CNT, read_pmbase32(PM1_CNT) & ~SCI_EN);
		printk(BIOS_DEBUG, "SMI#: ACPI disabled.\n");
		break;
	case APM_CNT_ACPI_ENABLE:
		write_pmbase32(PM1_CNT, read_pmbase32(PM1_CNT) | 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;
		}
		southbridge_update_gnvs(reg8, &smm_initialized);
		break;
	case APM_CNT_FINALIZE:
		if (mainboard_finalized) {
			printk(BIOS_DEBUG, "SMI#: Already finalized\n");
			return;
		}

		southbridge_finalize_all();
		mainboard_finalized = 1;
		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;

	pm1_sts = reset_pm1_status();
	dump_pm1_status(pm1_sts);

	/* While OSPM is not active, poweroff immediately
	 * on a power button event.
	 */
	if (pm1_sts & PWRBTN_STS) {
		// power button pressed
		u32 reg32;
		reg32 = (7 << 10) | (1 << 13);
		elog_gsmi_add_event(ELOG_TYPE_POWER_BUTTON);
		write_pmbase32(PM1_CNT, reg32);
	}
}

static void southbridge_smi_gpe0(void)
{
	u32 gpe0_sts;

	gpe0_sts = reset_gpe0_status();
	dump_gpe0_status(gpe0_sts);
}

static void southbridge_smi_gpi(void)
{
	u16 reg16;

	reg16 = reset_alt_gp_smi_status();
	reg16 &= read_pmbase16(ALT_GP_SMI_EN);

	mainboard_smi_gpi(reg16);

	if (reg16)
		printk(BIOS_DEBUG, "GPI (mask %04x)\n", reg16);

	write_pmbase16(ALT_GP_SMI_STS, reg16);
}

static void southbridge_smi_mc(void)
{
	u32 reg32;

	reg32 = read_pmbase32(SMI_EN);

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

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

static void southbridge_smi_tco(void)
{
	u32 tco_sts;

	tco_sts = reset_tco_status();

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

	if (tco_sts & (1 << 8)) { // BIOSWR
		u8 bios_cntl;

		bios_cntl = pci_read_config16(PCI_DEV(0, 0x1f, 0), 0xdc);

		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(PCI_DEV(0, 0x1f, 0), 0xdc,
					(bios_cntl & ~1));
		} /* No else for now? */
	} else if (tco_sts & (1 << 3)) { /* TIMEOUT */
		/* Handle TCO timeout */
		printk(BIOS_DEBUG, "TCO Timeout.\n");
	} else {
		dump_tco_status(tco_sts);
	}
}

static void southbridge_smi_periodic(void)
{
	u32 reg32;

	reg32 = read_pmbase32(SMI_EN);

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

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

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, dump = 0;
	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 = reset_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);
				dump = 1;
			}
		}
	}

	if (dump) {
		dump_smi_status(smi_sts);
	}
}
