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

#include <arch/io.h>
#include <device/pci_ops.h>
#include <console/console.h>
#include <delay.h>
#include <halt.h>

#include "me.h"
#include "pch.h"

static const char *me_ack_values[] = {
	[ME_HFS_ACK_NO_DID]	= "No DID Ack received",
	[ME_HFS_ACK_RESET]	= "Non-power cycle reset",
	[ME_HFS_ACK_PWR_CYCLE]	= "Power cycle reset",
	[ME_HFS_ACK_S3]		= "Go to S3",
	[ME_HFS_ACK_S4]		= "Go to S4",
	[ME_HFS_ACK_S5]		= "Go to S5",
	[ME_HFS_ACK_GBL_RESET]	= "Global Reset",
	[ME_HFS_ACK_CONTINUE]	= "Continue to boot"
};

void intel_early_me_status(void)
{
	union me_hfs hfs = { .raw = pci_read_config32(PCH_ME_DEV, PCI_ME_HFS) };
	union me_hfs2 hfs2 = { .raw = pci_read_config32(PCH_ME_DEV, PCI_ME_HFS2) };

	intel_me_status(hfs, hfs2);
}

int intel_early_me_init(void)
{
	int count;
	union me_uma uma;
	union me_hfs hfs;

	printk(BIOS_INFO, "Intel ME early init\n");

	/* Wait for ME UMA SIZE VALID bit to be set */
	/* FIXME: ME9 BGW indicates a 5 sec poll timeout. */
	for (count = ME_RETRY; count > 0; --count) {
		uma.raw = pci_read_config32(PCH_ME_DEV, PCI_ME_UMA);
		if (uma.valid)
			break;
		udelay(ME_DELAY);
	}
	if (!count) {
		printk(BIOS_ERR, "ME is not ready!\n");
		return -1;
	}

	/* Check for valid firmware */
	hfs.raw = pci_read_config32(PCH_ME_DEV, PCI_ME_HFS);
	if (hfs.fpt_bad) {
		printk(BIOS_WARNING, "ME has bad firmware\n");
		return -1;
	}

	printk(BIOS_INFO, "Intel ME firmware is ready\n");
	return 0;
}

int intel_early_me_uma_size(void)
{
	union me_uma uma = { .raw = pci_read_config32(PCH_ME_DEV, PCI_ME_UMA) };

	if (uma.valid) {
		printk(BIOS_DEBUG, "ME: Requested %uMB UMA\n", uma.size);
		return uma.size;
	}

	printk(BIOS_DEBUG, "ME: Invalid UMA size\n");
	return 0;
}

static inline void set_global_reset(int enable)
{
	u32 pmir = pci_read_config32(PCH_LPC_DEV, PMIR);

	/* CF9GR indicates a Global Reset */
	if (enable)
		pmir |= PMIR_CF9GR;
	else
		pmir &= ~PMIR_CF9GR;

	pci_write_config32(PCH_LPC_DEV, PMIR, pmir);
}

int intel_early_me_init_done(u8 status)
{
	u8 reset;
	int count;
	u32 mebase_l, mebase_h;
	union me_hfs hfs;
	union me_did did = {
		.init_done = ME_INIT_DONE,
		.status = status
	};

	/* MEBASE from MESEG_BASE[35:20] */
	mebase_l = pci_read_config32(PCI_CPU_DEVICE, PCI_CPU_MEBASE_L);
	mebase_h = pci_read_config32(PCI_CPU_DEVICE, PCI_CPU_MEBASE_H) & 0xf;
	did.uma_base = (mebase_l >> 20) | (mebase_h << 12);

	/* Send message to ME */
	printk(BIOS_DEBUG, "ME: Sending Init Done with status: %d, "
	       "UMA base: 0x%04x\n", status, did.uma_base);

	pci_write_config32(PCH_ME_DEV, PCI_ME_H_GS, did.raw);

	/*
	 * The ME firmware does not respond with an ACK when NOMEM or ERROR
	 * are sent.
	 */
	if (status == ME_INIT_STATUS_NOMEM || status == ME_INIT_STATUS_ERROR)
		return 0;

	/* Must wait for ME acknowledgement */
	for (count = ME_RETRY; count > 0; --count) {
		hfs.raw = pci_read_config32(PCH_ME_DEV, PCI_ME_HFS);
		if (hfs.bios_msg_ack)
			break;
		udelay(ME_DELAY);
	}
	if (!count) {
		printk(BIOS_ERR, "ME failed to respond\n");
		return -1;
	}

	/* Return the requested BIOS action */
	printk(BIOS_NOTICE, "ME: Requested BIOS Action: %s\n",
	       me_ack_values[hfs.ack_data]);

	/* Check status after acknowledgement */
	intel_early_me_status();

	reset = 0;
	switch (hfs.ack_data) {
	case ME_HFS_ACK_CONTINUE:
		/* Continue to boot */
		return 0;
	case ME_HFS_ACK_RESET:
		/* Non-power cycle reset */
		set_global_reset(0);
		reset = 0x06;
		break;
	case ME_HFS_ACK_PWR_CYCLE:
		/* Power cycle reset */
		set_global_reset(0);
		reset = 0x0e;
		break;
	case ME_HFS_ACK_GBL_RESET:
		/* Global reset */
		set_global_reset(1);
		reset = 0x0e;
		break;
	case ME_HFS_ACK_S3:
	case ME_HFS_ACK_S4:
	case ME_HFS_ACK_S5:
		break;
	}

	/* Perform the requested reset */
	if (reset) {
		outb(reset, 0xcf9);
		halt();
	}
	return -1;
}