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

#include <cbmem.h>
#include <console/console.h>
#include <device/pci_def.h>
#include <device/pci_ops.h>
#include <stdint.h>
#include <device/device.h>
#include <boot/tables.h>
#include <acpi/acpi.h>
#include <northbridge/intel/x4x/memmap.h>
#include <northbridge/intel/x4x/chip.h>
#include <northbridge/intel/x4x/x4x.h>
#include <cpu/intel/smm_reloc.h>
#include <cpu/intel/speedstep.h>
#include <cpu/x86/smm.h>

static void mch_domain_read_resources(struct device *dev)
{
	u8 index;
	u64 tom, touud;
	u32 tolud;

	index = 3;

	pci_domain_read_resources(dev);

	struct device *mch = pcidev_on_root(0, 0);

	/* Top of Upper Usable DRAM, including remap */
	touud = pci_read_config16(mch, D0F0_TOUUD);
	touud <<= 20;

	/* Top of Lower Usable DRAM */
	tolud = pci_read_config16(mch, D0F0_TOLUD) & 0xfff0;
	tolud <<= 16;

	/* Top of Memory - does not account for any UMA */
	tom = pci_read_config16(mch, D0F0_TOM) & 0x01ff;
	tom <<= 26;

	printk(BIOS_DEBUG, "TOUUD 0x%llx TOLUD 0x%08x TOM 0x%llx\n", touud, tolud, tom);

	/* Report the memory regions */
	ram_from_to(dev, index++, 0, 0xa0000);
	mmio_from_to(dev, index++, 0xa0000, 0xc0000);
	reserved_ram_from_to(dev, index++, 0xc0000, 1 * MiB);
	ram_from_to(dev, index++, 1 * MiB, cbmem_top());

	/*
	 * If >= 4GB installed then memory from TOLUD to 4GB
	 * is remapped above TOM, TOUUD will account for both
	 */
	upper_ram_end(dev, index++, touud);

	uintptr_t tseg_base;
	size_t tseg_size;
	smm_region(&tseg_base, &tseg_size);
	mmio_from_to(dev, index++, tseg_base, tolud);
	reserved_ram_from_to(dev, index++, cbmem_top(), tseg_base);

	/* Reserve high memory where the NB BARs are up to 4GiB */
	mmio_from_to(dev, index++, DEFAULT_HECIBAR, 4ull * GiB);

	mmconf_resource(dev, index++);
}

static void mch_domain_set_resources(struct device *dev)
{
	struct resource *res;

	for (res = dev->resource_list; res; res = res->next)
		report_resource_stored(dev, res, "");

	assign_resources(dev->downstream);
}

static void mch_domain_init(struct device *dev)
{
	/* Enable SERR */
	pci_or_config16(dev, PCI_COMMAND, PCI_COMMAND_SERR);
}

static const char *northbridge_acpi_name(const struct device *dev)
{
	if (dev->path.type == DEVICE_PATH_DOMAIN)
		return "PCI0";

	if (!is_pci_dev_on_bus(dev, 0))
		return NULL;

	switch (dev->path.pci.devfn) {
	case PCI_DEVFN(0, 0):
		return "MCHC";
	}

	return NULL;
}

void northbridge_write_smram(u8 smram)
{
	struct device *dev = pcidev_on_root(0, 0);

	if (!dev)
		die("could not find pci 00:00.0!\n");

	pci_write_config8(dev, D0F0_SMRAM, smram);
}

struct device_operations x4x_pci_domain_ops = {
	.read_resources   = mch_domain_read_resources,
	.set_resources    = mch_domain_set_resources,
	.init             = mch_domain_init,
	.scan_bus         = pci_host_bridge_scan_bus,
	.write_acpi_tables = northbridge_write_acpi_tables,
	.acpi_fill_ssdt   = generate_cpu_entries,
	.acpi_name        = northbridge_acpi_name,
};

struct device_operations x4x_cpu_bus_ops = {
	.read_resources   = noop_read_resources,
	.set_resources    = noop_set_resources,
	.init             = mp_cpu_bus_init,
};

static void hide_pci_fn(const int dev_bit_base, const struct device *dev)
{
	if (!dev || dev->enabled)
		return;
	const unsigned int fn = PCI_FUNC(dev->path.pci.devfn);
	const struct device *const d0f0 = pcidev_on_root(0, 0);
	pci_update_config32(d0f0, D0F0_DEVEN, ~(1 << (dev_bit_base + fn)), 0);
}

static void hide_pci_dev(const int dev, int functions, const int dev_bit_base)
{
	for (; functions >= 0; functions--)
		hide_pci_fn(dev_bit_base, pcidev_on_root(dev, functions));
}

static void x4x_init(void *const chip_info)
{
	struct device *const d0f0 = pcidev_on_root(0x0, 0);

	/* Hide internal functions based on devicetree info. */
	hide_pci_dev(6, 0, 13); /* PEG1: only on P45 */
	hide_pci_dev(3, 3, 6); /* ME */
	hide_pci_dev(2, 1, 3); /* IGD */
	hide_pci_dev(1, 0, 1); /* PEG0 */

	const u32 deven = pci_read_config32(d0f0, D0F0_DEVEN);
	if (!(deven & (0xf << 6)))
		pci_write_config32(d0f0, D0F0_DEVEN, deven & ~(1 << 14));
}

struct chip_operations northbridge_intel_x4x_ops = {
	.name = "Intel 4-Series Northbridge",
	.init = x4x_init,
};

bool northbridge_support_slfm(void)
{
	return false;
}