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

#include <commonlib/helpers.h>
#include <console/console.h>
#include <acpi/acpi.h>
#include <stdint.h>
#include <delay.h>
#include <cpu/intel/haswell/haswell.h>
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_def.h>
#include <device/pci_ids.h>
#include <device/pci_ops.h>
#include <boot/tables.h>
#include <security/intel/txt/txt_register.h>

#include "chip.h"
#include "haswell.h"

static int get_pcie_bar(struct device *dev, unsigned int index, u32 *base, u32 *len)
{
	u32 pciexbar_reg, mask;

	*base = 0;
	*len = 0;

	pciexbar_reg = pci_read_config32(dev, index);

	if (!(pciexbar_reg & (1 << 0)))
		return 0;

	switch ((pciexbar_reg >> 1) & 3) {
	case 0: /* 256MB */
		mask = (1UL << 31) | (1 << 30) | (1 << 29) | (1 << 28);
		*base = pciexbar_reg & mask;
		*len = 256 * 1024 * 1024;
		return 1;
	case 1: /* 128M */
		mask = (1UL << 31) | (1 << 30) | (1 << 29) | (1 << 28);
		mask |= (1 << 27);
		*base = pciexbar_reg & mask;
		*len = 128 * 1024 * 1024;
		return 1;
	case 2: /* 64M */
		mask = (1UL << 31) | (1 << 30) | (1 << 29) | (1 << 28);
		mask |= (1 << 27) | (1 << 26);
		*base = pciexbar_reg & mask;
		*len = 64 * 1024 * 1024;
		return 1;
	}

	return 0;
}

int decode_pcie_bar(u32 *const base, u32 *const len)
{
	return get_pcie_bar(pcidev_on_root(0, 0), PCIEXBAR, base, len);
}

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

	if (dev->path.type != DEVICE_PATH_PCI || dev->bus->secondary != 0)
		return NULL;

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

	return NULL;
}

/*
 * TODO: We could determine how many PCIe busses we need in the bar.
 *       For now, that number is hardcoded to a max of 64.
 */
static struct device_operations pci_domain_ops = {
	.read_resources    = pci_domain_read_resources,
	.set_resources     = pci_domain_set_resources,
	.scan_bus          = pci_domain_scan_bus,
	.acpi_name         = northbridge_acpi_name,
	.write_acpi_tables = northbridge_write_acpi_tables,
};

static int get_bar(struct device *dev, unsigned int index, u32 *base, u32 *len)
{
	u32 bar = pci_read_config32(dev, index);

	/* If not enabled don't report it */
	if (!(bar & 0x1))
		return 0;

	/* Knock down the enable bit */
	*base = bar & ~1;

	return 1;
}

/*
 * There are special BARs that actually are programmed in the MCHBAR. These Intel special
 * features, but they do consume resources that need to be accounted for.
 */
static int get_bar_in_mchbar(struct device *dev, unsigned int index, u32 *base, u32 *len)
{
	u32 bar = MCHBAR32(index);

	/* If not enabled don't report it */
	if (!(bar & 0x1))
		return 0;

	/* Knock down the enable bit */
	*base = bar & ~1;

	return 1;
}

struct fixed_mmio_descriptor {
	unsigned int index;
	u32 size;
	int (*get_resource)(struct device *dev, unsigned int index, u32 *base, u32 *size);
	const char *description;
};

#define SIZE_KB(x) ((x) * 1024)
struct fixed_mmio_descriptor mc_fixed_resources[] = {
	{ PCIEXBAR, SIZE_KB(0),  get_pcie_bar,      "PCIEXBAR" },
	{ MCHBAR,   SIZE_KB(32), get_bar,           "MCHBAR"   },
	{ DMIBAR,   SIZE_KB(4),  get_bar,           "DMIBAR"   },
	{ EPBAR,    SIZE_KB(4),  get_bar,           "EPBAR"    },
	{ GDXCBAR,  SIZE_KB(4),  get_bar_in_mchbar, "GDXCBAR"  },
	{ EDRAMBAR, SIZE_KB(16), get_bar_in_mchbar, "EDRAMBAR" },
};
#undef SIZE_KB

/* Add all known fixed MMIO ranges that hang off the host bridge/memory controller device. */
static void mc_add_fixed_mmio_resources(struct device *dev)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(mc_fixed_resources); i++) {
		u32 base;
		u32 size;
		struct resource *resource;
		unsigned int index;

		size = mc_fixed_resources[i].size;
		index = mc_fixed_resources[i].index;
		if (!mc_fixed_resources[i].get_resource(dev, index, &base, &size))
			continue;

		resource = new_resource(dev, mc_fixed_resources[i].index);
		resource->flags = IORESOURCE_MEM | IORESOURCE_FIXED | IORESOURCE_STORED |
				  IORESOURCE_RESERVE | IORESOURCE_ASSIGNED;

		resource->base = base;
		resource->size = size;
		printk(BIOS_DEBUG, "%s: Adding %s @ %x 0x%08lx-0x%08lx.\n",
		       __func__, mc_fixed_resources[i].description, index,
		       (unsigned long)base, (unsigned long)(base + size - 1));
	}
}

/*
 * Host Memory Map:
 *
 * +--------------------------+ TOUUD
 * |                          |
 * +--------------------------+ 4GiB
 * |     PCI Address Space    |
 * +--------------------------+ TOLUD (also maps into MC address space)
 * |     iGD                  |
 * +--------------------------+ BDSM
 * |     GTT                  |
 * +--------------------------+ BGSM
 * |     TSEG                 |
 * +--------------------------+ TSEGMB
 * |     DPR                  |
 * +--------------------------+ (DPR top - DPR size)
 * |     Usage DRAM           |
 * +--------------------------+ 0
 *
 * Some of the base registers above can be equal, making the size of the regions within 0.
 * This is because the memory controller internally subtracts the base registers from each
 * other to determine sizes of the regions. In other words, the memory map regions are always
 * in a fixed order, no matter what sizes they have.
 */

struct map_entry {
	int reg;
	int is_64_bit;
	int is_limit;
	const char *description;
};

static void read_map_entry(struct device *dev, struct map_entry *entry, uint64_t *result)
{
	uint64_t value;
	uint64_t mask;

	/* All registers have a 1MiB granularity */
	mask = ((1ULL << 20) - 1);
	mask = ~mask;

	value = 0;

	if (entry->is_64_bit) {
		value = pci_read_config32(dev, entry->reg + 4);
		value <<= 32;
	}

	value |= pci_read_config32(dev, entry->reg);
	value &= mask;

	if (entry->is_limit)
		value |= ~mask;

	*result = value;
}

#define MAP_ENTRY(reg_, is_64_, is_limit_, desc_) \
	{ \
		.reg = reg_,           \
		.is_64_bit = is_64_,   \
		.is_limit = is_limit_, \
		.description = desc_,  \
	}

#define MAP_ENTRY_BASE_32(reg_, desc_)	MAP_ENTRY(reg_, 0, 0, desc_)
#define MAP_ENTRY_BASE_64(reg_, desc_)	MAP_ENTRY(reg_, 1, 0, desc_)
#define MAP_ENTRY_LIMIT_64(reg_, desc_)	MAP_ENTRY(reg_, 1, 1, desc_)

enum {
	TOM_REG,
	TOUUD_REG,
	MESEG_BASE_REG,
	MESEG_LIMIT_REG,
	REMAP_BASE_REG,
	REMAP_LIMIT_REG,
	TOLUD_REG,
	BGSM_REG,
	BDSM_REG,
	TSEG_REG,
	/* Must be last */
	NUM_MAP_ENTRIES,
};

static struct map_entry memory_map[NUM_MAP_ENTRIES] = {
	[TOM_REG]         = MAP_ENTRY_BASE_64(TOM, "TOM"),
	[TOUUD_REG]       = MAP_ENTRY_BASE_64(TOUUD, "TOUUD"),
	[MESEG_BASE_REG]  = MAP_ENTRY_BASE_64(MESEG_BASE, "MESEG_BASE"),
	[MESEG_LIMIT_REG] = MAP_ENTRY_LIMIT_64(MESEG_LIMIT, "MESEG_LIMIT"),
	[REMAP_BASE_REG]  = MAP_ENTRY_BASE_64(REMAPBASE, "REMAP_BASE"),
	[REMAP_LIMIT_REG] = MAP_ENTRY_LIMIT_64(REMAPLIMIT, "REMAP_LIMIT"),
	[TOLUD_REG]       = MAP_ENTRY_BASE_32(TOLUD, "TOLUD"),
	[BDSM_REG]        = MAP_ENTRY_BASE_32(BDSM, "BDSM"),
	[BGSM_REG]        = MAP_ENTRY_BASE_32(BGSM, "BGSM"),
	[TSEG_REG]        = MAP_ENTRY_BASE_32(TSEG, "TSEGMB"),
};

static void mc_read_map_entries(struct device *dev, uint64_t *values)
{
	int i;
	for (i = 0; i < NUM_MAP_ENTRIES; i++) {
		read_map_entry(dev, &memory_map[i], &values[i]);
	}
}

static void mc_report_map_entries(struct device *dev, uint64_t *values)
{
	int i;
	for (i = 0; i < NUM_MAP_ENTRIES; i++) {
		printk(BIOS_DEBUG, "MC MAP: %s: 0x%llx\n",
		       memory_map[i].description, values[i]);
	}
	/* One can validate the BDSM and BGSM against the GGC */
	printk(BIOS_DEBUG, "MC MAP: GGC: 0x%x\n", pci_read_config16(dev, GGC));
}

static void mc_add_dram_resources(struct device *dev, int *resource_cnt)
{
	unsigned long base_k, size_k, touud_k, index;
	struct resource *resource;
	uint64_t mc_values[NUM_MAP_ENTRIES];

	/* Read in the MAP registers and report their values */
	mc_read_map_entries(dev, &mc_values[0]);
	mc_report_map_entries(dev, &mc_values[0]);

	/* The DPR register is special */
	const union dpr_register dpr = {
		.raw = pci_read_config32(dev, DPR),
	};
	printk(BIOS_DEBUG, "MC MAP: DPR: 0x%x\n", dpr.raw);

	/*
	 * These are the host memory ranges that should be added:
	 * - 0 -> 0xa0000:    cacheable
	 * - 0xc0000 -> TSEG: cacheable
	 * - TSEG -> BGSM:    cacheable with standard MTRRs and reserved
	 * - BGSM -> TOLUD:   not cacheable with standard MTRRs and reserved
	 * - 4GiB -> TOUUD:   cacheable
	 *
	 * The default SMRAM space is reserved so that the range doesn't have to be saved
	 * during S3 Resume. Once marked reserved the OS cannot use the memory. This is a
	 * bit of an odd place to reserve the region, but the CPU devices don't have
	 * dev_ops->read_resources() called on them.
	 *
	 * The range 0xa0000 -> 0xc0000 does not have any resources associated with it to
	 * handle legacy VGA memory. If this range is not omitted the mtrr code will setup
	 * the area as cacheable, causing VGA access to not work.
	 *
	 * The TSEG region is mapped as cacheable so that one can perform SMRAM relocation
	 * faster. Once the SMRR is enabled, the SMRR takes precedence over the existing
	 * MTRRs covering this region.
	 *
	 * It should be noted that cacheable entry types need to be added in order. The reason
	 * is that the current MTRR code assumes this and falls over itself if it isn't.
	 *
	 * The resource index starts low and should not meet or exceed PCI_BASE_ADDRESS_0.
	 */
	index = *resource_cnt;

	/* 0 - > 0xa0000 */
	base_k = 0;
	size_k = (0xa0000 >> 10) - base_k;
	ram_resource(dev, index++, base_k, size_k);

	/* 0xc0000 -> DPR base */
	base_k = 0xc0000 >> 10;
	size_k = (unsigned long)(mc_values[TSEG_REG] >> 10) - (base_k + dpr.size);
	ram_resource(dev, index++, base_k, size_k);

	/* DPR base -> TSEG */
	if (dpr.size) {
		resource = new_resource(dev, index++);
		resource->base = (dpr.top - dpr.size) * MiB;
		resource->size = dpr.size * MiB;
		resource->flags = IORESOURCE_MEM | IORESOURCE_STORED | IORESOURCE_CACHEABLE |
				  IORESOURCE_RESERVE | IORESOURCE_ASSIGNED | IORESOURCE_FIXED;
	}

	/* TSEG -> BGSM */
	resource = new_resource(dev, index++);
	resource->base = mc_values[TSEG_REG];
	resource->size = mc_values[BGSM_REG] - resource->base;
	resource->flags = IORESOURCE_MEM | IORESOURCE_FIXED | IORESOURCE_STORED |
			  IORESOURCE_RESERVE | IORESOURCE_ASSIGNED | IORESOURCE_CACHEABLE;

	/* BGSM -> TOLUD. If the IGD is disabled, BGSM can equal TOLUD. */
	if (mc_values[BGSM_REG] != mc_values[TOLUD_REG]) {
		resource = new_resource(dev, index++);
		resource->base = mc_values[BGSM_REG];
		resource->size = mc_values[TOLUD_REG] - resource->base;
		resource->flags = IORESOURCE_MEM | IORESOURCE_FIXED | IORESOURCE_STORED |
				  IORESOURCE_RESERVE | IORESOURCE_ASSIGNED;
	}

	/* 4GiB -> TOUUD */
	base_k = 4096 * 1024; /* 4GiB */
	touud_k = mc_values[TOUUD_REG] >> 10;
	size_k = touud_k - base_k;
	if (touud_k > base_k)
		ram_resource(dev, index++, base_k, size_k);

	/* Reserve everything between A segment and 1MB:
	 *
	 * 0xa0000 - 0xbffff: Legacy VGA
	 * 0xc0000 - 0xfffff: RAM
	 */
	mmio_resource(dev, index++, (0xa0000 >> 10), (0xc0000 - 0xa0000) >> 10);
	reserved_ram_resource(dev, index++, (0xc0000 >> 10), (0x100000 - 0xc0000) >> 10);

#if CONFIG(CHROMEOS_RAMOOPS)
	reserved_ram_resource(dev, index++,
			CONFIG_CHROMEOS_RAMOOPS_RAM_START >> 10,
			CONFIG_CHROMEOS_RAMOOPS_RAM_SIZE  >> 10);
#endif
	*resource_cnt = index;
}

static void mc_read_resources(struct device *dev)
{
	int index = 0;
	const bool vtd_capable = !(pci_read_config32(dev, CAPID0_A) & VTD_DISABLE);

	/* Read standard PCI resources */
	pci_dev_read_resources(dev);

	/* Add all fixed MMIO resources */
	mc_add_fixed_mmio_resources(dev);

	/* Add VT-d MMIO resources, if capable */
	if (vtd_capable) {
		mmio_resource(dev, index++, GFXVT_BASE_ADDRESS / KiB, GFXVT_BASE_SIZE / KiB);
		mmio_resource(dev, index++, VTVC0_BASE_ADDRESS / KiB, VTVC0_BASE_SIZE / KiB);
	}

	/* Calculate and add DRAM resources */
	mc_add_dram_resources(dev, &index);
}

/*
 * The Mini-HD audio device is disabled whenever the IGD is. This is because it provides
 * audio over the integrated graphics port(s), which requires the IGD to be functional.
 */
static void disable_devices(void)
{
	static const struct {
		const unsigned int devfn;
		const u32 mask;
		const char *const name;
	} nb_devs[] = {
		{ PCI_DEVFN(1, 2), DEVEN_D1F2EN, "PEG12" },
		{ PCI_DEVFN(1, 1), DEVEN_D1F1EN, "PEG11" },
		{ PCI_DEVFN(1, 0), DEVEN_D1F0EN, "PEG10" },
		{ PCI_DEVFN(2, 0), DEVEN_D2EN | DEVEN_D3EN, "IGD" },
		{ PCI_DEVFN(3, 0), DEVEN_D3EN, "Mini-HD audio" },
		{ PCI_DEVFN(4, 0), DEVEN_D4EN, "\"device 4\"" },
		{ PCI_DEVFN(7, 0), DEVEN_D7EN, "\"device 7\"" },
	};

	struct device *host_dev = pcidev_on_root(0, 0);
	u32 deven;
	size_t i;

	if (!host_dev)
		return;

	deven = pci_read_config32(host_dev, DEVEN);

	for (i = 0; i < ARRAY_SIZE(nb_devs); i++) {
		struct device *dev = pcidev_path_on_root(nb_devs[i].devfn);
		if (!dev || !dev->enabled) {
			printk(BIOS_DEBUG, "Disabling %s.\n", nb_devs[i].name);
			deven &= ~nb_devs[i].mask;
		}
	}

	pci_write_config32(host_dev, DEVEN, deven);
}

static void init_egress(void)
{
	/* VC0: Enable, ID0, TC0 */
	EPBAR32(EPVC0RCTL) = (1 << 31) | (0 << 24) | (1 << 0);

	/* No Low Priority Extended VCs, one Extended VC */
	EPBAR32(EPPVCCAP1) = (0 << 4) | (1 << 0);

	/* VC1: Enable, ID1, TC1 */
	EPBAR32(EPVC1RCTL) = (1 << 31) | (1 << 24) | (1 << 1);

	/* Poll the VC1 Negotiation Pending bit */
	while ((EPBAR16(EPVC1RSTS) & (1 << 1)) != 0)
		;
}

static void northbridge_dmi_init(void)
{
	const bool is_haswell_h = !CONFIG(INTEL_LYNXPOINT_LP);

	u16 reg16;
	u32 reg32;

	/* Steps prior to DMI ASPM */
	if (is_haswell_h) {
		/* Configure DMI De-Emphasis */
		reg16 = DMIBAR16(DMILCTL2);
		reg16 |= (1 << 6);	/* 0b: -6.0 dB, 1b: -3.5 dB */
		DMIBAR16(DMILCTL2) = reg16;

		reg32 = DMIBAR32(DMIL0SLAT);
		reg32 |= (1 << 31);
		DMIBAR32(DMIL0SLAT) = reg32;

		reg32 = DMIBAR32(DMILLTC);
		reg32 |= (1 << 29);
		DMIBAR32(DMILLTC) = reg32;

		reg32 = DMIBAR32(DMI_AFE_PM_TMR);
		reg32 &= ~0x1f;
		reg32 |= 0x13;
		DMIBAR32(DMI_AFE_PM_TMR) = reg32;
	}

	/* Clear error status bits */
	DMIBAR32(DMIUESTS) = 0xffffffff;
	DMIBAR32(DMICESTS) = 0xffffffff;

	if (is_haswell_h) {
		/* Enable ASPM L0s and L1 on SA link, should happen before PCH link */
		reg16 = DMIBAR16(DMILCTL);
		reg16 |= (1 << 1) | (1 << 0);
		DMIBAR16(DMILCTL) = reg16;
	}
}

static void northbridge_topology_init(void)
{
	const u32 eple_a[3] = { EPLE2A, EPLE3A, EPLE4A };
	const u32 eple_d[3] = { EPLE2D, EPLE3D, EPLE4D };

	u32 reg32;

	/* Set the CID1 Egress Port 0 Root Topology */
	reg32 = EPBAR32(EPESD);
	reg32 &= ~(0xff << 16);
	reg32 |= 1 << 16;
	EPBAR32(EPESD) = reg32;

	reg32 = EPBAR32(EPLE1D);
	reg32 &= ~(0xff << 16);
	reg32 |= 1 | (1 << 16);
	EPBAR32(EPLE1D) = reg32;
	EPBAR64(EPLE1A) = (uintptr_t)DEFAULT_DMIBAR;

	for (unsigned int i = 0; i <= 2; i++) {
		const struct device *const dev = pcidev_on_root(1, i);

		if (!dev || !dev->enabled)
			continue;

		EPBAR64(eple_a[i]) = (u64)PCI_DEV(0, 1, i);

		reg32 = EPBAR32(eple_d[i]);
		reg32 &= ~(0xff << 16);
		reg32 |= 1 | (1 << 16);
		EPBAR32(eple_d[i]) = reg32;

		pci_update_config32(dev, PEG_ESD, ~(0xff << 16), (1 << 16));
		pci_write_config32(dev, PEG_LE1A, (uintptr_t)DEFAULT_EPBAR);
		pci_write_config32(dev, PEG_LE1A + 4, 0);
		pci_update_config32(dev, PEG_LE1D, ~(0xff << 16), (1 << 16) | 1);

		/* Read and write to lock register */
		pci_or_config32(dev, PEG_DCAP2, 0);
	}

	/* Set the CID1 DMI Port Root Topology */
	reg32 = DMIBAR32(DMIESD);
	reg32 &= ~(0xff << 16);
	reg32 |= 1 << 16;
	DMIBAR32(DMIESD) = reg32;

	reg32 = DMIBAR32(DMILE1D);
	reg32 &= ~(0xffff << 16);
	reg32 |= 1 | (2 << 16);
	DMIBAR32(DMILE1D) = reg32;
	DMIBAR64(DMILE1A) = (uintptr_t)DEFAULT_RCBA;

	DMIBAR64(DMILE2A) = (uintptr_t)DEFAULT_EPBAR;
	reg32 = DMIBAR32(DMILE2D);
	reg32 &= ~(0xff << 16);
	reg32 |= 1 | (1 << 16);
	DMIBAR32(DMILE2D) = reg32;

	/* Program RO and Write-Once Registers */
	DMIBAR32(DMIPVCCAP1) = DMIBAR32(DMIPVCCAP1);
	DMIBAR32(DMILCAP)    = DMIBAR32(DMILCAP);
}

static void northbridge_init(struct device *dev)
{
	u8 bios_reset_cpl, pair;

	init_egress();
	northbridge_dmi_init();
	northbridge_topology_init();

	/* Enable Power Aware Interrupt Routing. */
	pair = MCHBAR8(INTRDIRCTL);
	pair &= ~0x7;	/* Clear 2:0 */
	pair |= 0x4;	/* Fixed Priority */
	MCHBAR8(INTRDIRCTL) = pair;

	disable_devices();

	/*
	 * Set bits 0 + 1 of BIOS_RESET_CPL to indicate to the CPU
	 * that BIOS has initialized memory and power management.
	 */
	bios_reset_cpl = MCHBAR8(BIOS_RESET_CPL);
	bios_reset_cpl |= 3;
	MCHBAR8(BIOS_RESET_CPL) = bios_reset_cpl;
	printk(BIOS_DEBUG, "Set BIOS_RESET_CPL\n");

	/* Configure turbo power limits 1ms after reset complete bit. */
	mdelay(1);
	set_power_limits(28);

	/* Set here before graphics PM init. */
	MCHBAR32(MMIO_PAVP_MSG) = 0x00100001;
}

static struct device_operations mc_ops = {
	.read_resources         = mc_read_resources,
	.set_resources          = pci_dev_set_resources,
	.enable_resources       = pci_dev_enable_resources,
	.init                   = northbridge_init,
	.acpi_fill_ssdt		= generate_cpu_entries,
	.ops_pci                = &pci_dev_ops_pci,
};

static const unsigned short mc_pci_device_ids[] = {
	0x0c00, /* Desktop */
	0x0c04, /* Mobile */
	0x0a04, /* ULT */
	0x0c08, /* Server */
	0x0d00, /* Crystal Well Desktop */
	0x0d04, /* Crystal Well Mobile */
	0x0d08, /* Crystal Well Server (by extrapolation) */
	0
};

static const struct pci_driver mc_driver_hsw __pci_driver = {
	.ops     = &mc_ops,
	.vendor  = PCI_VENDOR_ID_INTEL,
	.devices = mc_pci_device_ids,
};

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

static void enable_dev(struct device *dev)
{
	/* Set the operations if it is a special bus type. */
	if (dev->path.type == DEVICE_PATH_DOMAIN) {
		dev->ops = &pci_domain_ops;
	} else if (dev->path.type == DEVICE_PATH_CPU_CLUSTER) {
		dev->ops = &cpu_bus_ops;
	}
}

struct chip_operations northbridge_intel_haswell_ops = {
	CHIP_NAME("Intel i7 (Haswell) integrated Northbridge")
	.enable_dev = enable_dev,
};