/* SPDX-License-Identifier: GPL-2.0-or-later */

#include <assert.h>
#include <console/console.h>
#include <post.h>
#include <device/pci.h>
#include <soc/chip_common.h>
#include <soc/soc_util.h>
#include <soc/util.h>
#include <stdlib.h>

static const STACK_RES *domain_to_stack_res(const struct device *dev)
{
	assert(dev->path.type == DEVICE_PATH_DOMAIN);
	const union xeon_domain_path dn = {
		.domain_path = dev->path.domain.domain
	};

	const IIO_UDS *hob = get_iio_uds();
	assert(hob != NULL);

	return &hob->PlatformData.IIO_resource[dn.socket].StackRes[dn.stack];
}

/**
 * Find a device of a given vendor and type for the specified socket.
 * The function iterates over all PCI domains of the specified socket
 * and matches the PCI vendor and device ID.
 *
 * @param socket The socket where to search for the device.
 * @param vendor A PCI vendor ID (e.g. 0x8086 for Intel).
 * @param device A PCI device ID.
 * @return Pointer to the device struct.
 */
struct device *dev_find_device_on_socket(uint8_t socket, u16 vendor, u16 device)
{
	struct device *domain, *dev = NULL;
	union xeon_domain_path dn;

	while ((dev = dev_find_device(vendor, device, dev))) {
		domain = dev_get_pci_domain(dev);
		if (!domain)
			continue;
		dn.domain_path = domain->path.domain.domain;
		if (dn.socket != socket)
			continue;
		return dev;
	}

	return NULL;
}

/**
 * Returns the socket ID where the specified device is connected to.
 * This is an integer in the range [0, CONFIG_MAX_SOCKET).
 *
 * @param dev The device to look up
 *
 * @return Socket ID the device is attached to, negative number on error.
 */
int iio_pci_domain_socket_from_dev(struct device *dev)
{
	struct device *domain;
	union xeon_domain_path dn;

	if (dev->path.type == DEVICE_PATH_DOMAIN)
		domain = dev;
	else
		domain = dev_get_pci_domain(dev);

	if (!domain)
		return -1;

	dn.domain_path = domain->path.domain.domain;

	return dn.socket;
}

/**
 * Returns the stack ID where the specified device is connected to.
 * This is an integer in the range [0, MAX_IIO_STACK).
 *
 * @param dev The device to look up
 *
 * @return Stack ID the device is attached to, negative number on error.
 */
int iio_pci_domain_stack_from_dev(struct device *dev)
{
	struct device *domain;
	union xeon_domain_path dn;

	if (dev->path.type == DEVICE_PATH_DOMAIN)
		domain = dev;
	else
		domain = dev_get_pci_domain(dev);

	if (!domain)
		return -1;

	dn.domain_path = domain->path.domain.domain;

	return dn.stack;
}

void iio_pci_domain_read_resources(struct device *dev)
{
	struct resource *res;
	const STACK_RES *sr = domain_to_stack_res(dev);

	if (!sr)
		return;

	int index = 0;

	if (dev->path.domain.domain == 0) {
		/* The 0 - 0xfff IO range is not reported by the HOB but still gets decoded */
		res = new_resource(dev, index++);
		res->base = 0;
		res->size = 0x1000;
		res->limit = 0xfff;
		res->flags = IORESOURCE_IO | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED;
	}

	if (sr->PciResourceIoBase < sr->PciResourceIoLimit) {
		res = new_resource(dev, index++);
		res->base = sr->PciResourceIoBase;
		res->limit = sr->PciResourceIoLimit;
		res->size = res->limit - res->base + 1;
		res->flags = IORESOURCE_IO | IORESOURCE_ASSIGNED;
	}

	if (sr->PciResourceMem32Base < sr->PciResourceMem32Limit) {
		res = new_resource(dev, index++);
		res->base = sr->PciResourceMem32Base;
		res->limit = sr->PciResourceMem32Limit;
		res->size = res->limit - res->base + 1;
		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
	}

	if (sr->PciResourceMem64Base < sr->PciResourceMem64Limit) {
		res = new_resource(dev, index++);
		res->base = sr->PciResourceMem64Base;
		res->limit = sr->PciResourceMem64Limit;
		res->size = res->limit - res->base + 1;
		res->flags = IORESOURCE_MEM | IORESOURCE_ASSIGNED;
	}
}

void iio_pci_domain_scan_bus(struct device *dev)
{
	const STACK_RES *sr = domain_to_stack_res(dev);
	if (!sr)
		return;

	struct bus *bus = alloc_bus(dev);
	bus->secondary = sr->BusBase;
	bus->subordinate = sr->BusBase;
	bus->max_subordinate = sr->BusLimit;

	printk(BIOS_SPEW, "Scanning IIO stack %d: busses %x-%x\n", dev->path.domain.domain,
	       dev->downstream->secondary, dev->downstream->max_subordinate);
	pci_host_bridge_scan_bus(dev);
}

/*
 * Used by IIO stacks for PCIe bridges. Those contain 1 PCI host bridges,
 *  all the bus numbers on the IIO stack can be used for this bridge
 */
static struct device_operations iio_pcie_domain_ops = {
	.read_resources = iio_pci_domain_read_resources,
	.set_resources = pci_domain_set_resources,
	.scan_bus = iio_pci_domain_scan_bus,
};

/*
 * Used by UBOX stacks. Those contain multiple PCI host bridges, each having
 * only one bus with UBOX devices. UBOX devices have no resources.
 */
static struct device_operations ubox_pcie_domain_ops = {
	.read_resources = noop_read_resources,
	.set_resources = noop_set_resources,
	.scan_bus = pci_host_bridge_scan_bus,
};

/*
 * On the first Xeon-SP generations there are no separate UBOX stacks,
 * and the UBOX devices reside on the first and second IIO. Starting
 * with 3rd gen Xeon-SP the UBOX devices are located on their own IIO.
 */
static void soc_create_ubox_domains(const union xeon_domain_path dp, struct bus *upstream,
				    const unsigned int bus_base, const unsigned int bus_limit)
{
	union xeon_domain_path new_path = {
		.domain_path = dp.domain_path
	};

	for (int i = bus_base; i <= bus_limit; i++) {
		new_path.bus = i;

		struct device_path path = {
			.type = DEVICE_PATH_DOMAIN,
			.domain = {
				.domain = new_path.domain_path,
			},
		};
		struct device *const domain = alloc_dev(upstream, &path);
		if (!domain)
			die("%s: out of memory.\n", __func__);

		domain->ops = &ubox_pcie_domain_ops;

		struct bus *const bus = alloc_bus(domain);
		bus->secondary = i;
		bus->subordinate = bus->secondary;
		bus->max_subordinate = bus->secondary;
	}
}

/* Attach stack as domains */
void attach_iio_stacks(struct device *dev)
{
	const IIO_UDS *hob = get_iio_uds();
	union xeon_domain_path dn = { .domain_path = 0 };
	if (!hob)
		return;

	for (int s = 0; s < hob->PlatformData.numofIIO; ++s) {
		for (int x = 0; x < MAX_LOGIC_IIO_STACK; ++x) {
			if (s == 0 && x == 0)
				continue;

			const STACK_RES *ri = &hob->PlatformData.IIO_resource[s].StackRes[x];
			if (ri->BusBase > ri->BusLimit)
				continue;

			/* Prepare domain path */
			dn.socket = s;
			dn.stack = x;
			dn.bus = ri->BusBase;

			if (is_ubox_stack_res(ri)) {
				soc_create_ubox_domains(dn, dev->upstream, ri->BusBase, ri->BusLimit);
			} else if (is_pcie_iio_stack_res(ri)) {
				struct device_path path;
				path.type = DEVICE_PATH_DOMAIN;
				path.domain.domain = dn.domain_path;
				struct device *iio_domain = alloc_dev(dev->upstream, &path);
				if (iio_domain == NULL)
					die("%s: out of memory.\n", __func__);

				iio_domain->ops = &iio_pcie_domain_ops;
			} else if (CONFIG(HAVE_IOAT_DOMAINS))
				soc_create_ioat_domains(dn, dev->upstream, ri);
		}
	}
}