/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2017 Advanced Micro Devices, Inc.
 * Copyright (C) 2014 Alexandru Gagniuc <mr.nuke.me@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <console/console.h>
#include <cpu/x86/smm.h>
#include <cpu/x86/cache.h>
#include <arch/acpi.h>
#include <arch/hlt.h>
#include <delay.h>
#include <device/pci_def.h>
#include <soc/smi.h>
#include <soc/southbridge.h>
#include <elog.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)
{
	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;
}

static void southbridge_smi_gsmi(void)
{
	u8 sub_command;
	amd64_smm_state_save_area_t *io_smi;
	u32 reg_ebx;

	io_smi = find_save_state(ELOG_GSMI_APM_CNT);
	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);
}

static void sb_apmc_smi_handler(void)
{
	u32 reg32;
	const uint8_t cmd = inb(pm_acpi_smi_cmd_port());

	switch (cmd) {
	case APM_CNT_ACPI_ENABLE:
		reg32 = acpi_read32(MMIO_ACPI_PM1_CNT_BLK);
		reg32 |= (1 << 0);	/* SCI_EN */
		acpi_write32(MMIO_ACPI_PM1_CNT_BLK, reg32);
		break;
	case APM_CNT_ACPI_DISABLE:
		reg32 = acpi_read32(MMIO_ACPI_PM1_CNT_BLK);
		reg32 &= ~(1 << 0);	/* clear SCI_EN */
		acpi_write32(MMIO_ACPI_PM1_CNT_BLK, reg32);
		break;
	case ELOG_GSMI_APM_CNT:
		if (IS_ENABLED(CONFIG_ELOG_GSMI))
			southbridge_smi_gsmi();
		break;
	}

	mainboard_smi_apmc(cmd);
}

static void disable_all_smi_status(void)
{
	smi_write32(SMI_SCI_STATUS, smi_read32(SMI_SCI_STATUS));
	smi_write32(SMI_REG_SMISTS0, smi_read32(SMI_REG_SMISTS0));
	smi_write32(SMI_REG_SMISTS1, smi_read32(SMI_REG_SMISTS1));
	smi_write32(SMI_REG_SMISTS2, smi_read32(SMI_REG_SMISTS2));
	smi_write32(SMI_REG_SMISTS3, smi_read32(SMI_REG_SMISTS3));
	smi_write32(SMI_REG_SMISTS4, smi_read32(SMI_REG_SMISTS4));
}

static void sb_slp_typ_handler(void)
{
	uint32_t pci_ctrl, reg32;
	uint16_t pm1cnt, reg16;
	uint8_t slp_typ, rst_ctrl;

	/* Figure out SLP_TYP */
	pm1cnt = acpi_read16(MMIO_ACPI_PM1_CNT_BLK);
	printk(BIOS_SPEW, "SMI#: SLP = 0x%04x\n", pm1cnt);
	slp_typ = acpi_sleep_from_pm1(pm1cnt);

	/* Do any mainboard sleep handling */
	mainboard_smi_sleep(slp_typ);

	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");
		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");
		break;
	default:
		printk(BIOS_DEBUG, "SMI#: ERROR: SLP_TYP reserved\n");
		break;
	}

	if (slp_typ >= ACPI_S3) {
		/* Sleep Type Elog S3, S4, and S5 entry */
		if (IS_ENABLED(CONFIG_ELOG_GSMI))
			elog_add_event_byte(ELOG_TYPE_ACPI_ENTER, slp_typ);

		wbinvd();

		disable_all_smi_status();

		/* Do not send SMI before AcpiPm1CntBlkx00[SlpTyp] */
		pci_ctrl = pm_read32(PM_PCI_CTRL);
		pci_ctrl &= ~FORCE_SLPSTATE_RETRY;
		pci_ctrl |= FORCE_STPCLK_RETRY;
		pm_write32(PM_PCI_CTRL, pci_ctrl);

		/* Enable SlpTyp */
		rst_ctrl = pm_read8(PM_RST_CTRL1);
		rst_ctrl |= SLPTYPE_CONTROL_EN;
		pm_write8(PM_RST_CTRL1, rst_ctrl);

		/*
		 * Before the final command, check if there's pending wake
		 * event. Read enable first, so that reading the actual status
		 * is as close as possible to entering S3. The idea is to
		 * minimize the opportunity for a wake event to happen before
		 * actually entering S3. If there's a pending wake event, log
		 * it and continue normal path. S3 will fail and the wake event
		 * becomes a SCI.
		 */
		if (IS_ENABLED(CONFIG_ELOG_GSMI)) {
			reg16 = acpi_read16(MMIO_ACPI_PM1_EN);
			reg16 &= acpi_read16(MMIO_ACPI_PM1_STS);
			if (reg16)
				elog_add_extended_event(
						ELOG_SLEEP_PENDING_PM1_WAKE,
						(u32)reg16);

			reg32 = acpi_read32(MMIO_ACPI_GPE0_EN);
			reg32 &= acpi_read32(MMIO_ACPI_GPE0_STS);
			if (reg32)
				elog_add_extended_event(
						ELOG_SLEEP_PENDING_GPE0_WAKE,
						reg32);
		} /* if (IS_ENABLED(CONFIG_ELOG_GSMI)) */

		/*
		 * An IO cycle is required to trigger the STPCLK/STPGNT
		 * handshake when the Pm1 write is reissued.
		 */
		outw(pm1cnt | SLP_EN, pm_acpi_pm_cnt_blk());
		hlt();
	}
}

int southbridge_io_trap_handler(int smif)
{
	return 0;
}

/*
 * Table of functions supported in the SMI handler.  Note that SMI source setup
 * in southbridge.c is unrelated to this list.
 */
static const struct smi_sources_t smi_sources[] = {
	{ .type = SMITYPE_SMI_CMD_PORT, .handler = sb_apmc_smi_handler },
	{ .type = SMITYPE_SLP_TYP, .handler = sb_slp_typ_handler},
};

static void process_smi_sci(void)
{
	const uint32_t status = smi_read32(SMI_SCI_STATUS);

	/* Clear events to prevent re-entering SMI if event isn't handled */
	smi_write32(SMI_SCI_STATUS, status);
}

static void *get_source_handler(int source)
{
	int i;

	for (i = 0 ; i < ARRAY_SIZE(smi_sources) ; i++)
		if (smi_sources[i].type == source)
			return smi_sources[i].handler;

	return NULL;
}

static void process_smi_sources(uint32_t reg)
{
	const uint32_t status = smi_read32(reg);
	int bit_zero = 32 / sizeof(uint32_t) * (reg - SMI_REG_SMISTS0);
	void (*source_handler)(void);
	int i;

	for (i = 0 ; i < 32 ; i++) {
		if (status & (1 << i)) {
			source_handler = get_source_handler(i + bit_zero);
			if (source_handler)
				source_handler();
		}
	}

	if (reg == SMI_REG_SMISTS0)
		if (status & GEVENT_MASK)
			/* Gevent[23:0] are assumed to be mainboard-specific */
			mainboard_smi_gpi(status & GEVENT_MASK);

	/* Clear all events in this register */
	smi_write32(reg, status);
}

void southbridge_smi_handler(void)
{
	const uint16_t smi_src = smi_read16(SMI_REG_POINTER);

	if (smi_src & SMI_STATUS_SRC_SCI)
		process_smi_sci();
	if (smi_src & SMI_STATUS_SRC_0)
		process_smi_sources(SMI_REG_SMISTS0);
	if (smi_src & SMI_STATUS_SRC_1)
		process_smi_sources(SMI_REG_SMISTS1);
	if (smi_src & SMI_STATUS_SRC_2)
		process_smi_sources(SMI_REG_SMISTS2);
	if (smi_src & SMI_STATUS_SRC_3)
		process_smi_sources(SMI_REG_SMISTS3);
	if (smi_src & SMI_STATUS_SRC_4)
		process_smi_sources(SMI_REG_SMISTS4);
}

void southbridge_smi_set_eos(void)
{
	uint32_t reg = smi_read32(SMI_REG_SMITRIG0);
	reg |= SMITRG0_EOS;
	smi_write32(SMI_REG_SMITRIG0, reg);
}