[mirror_ubuntu-jammy-kernel.git] / drivers / pci / of.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * PCI <-> OF mapping helpers
 *
 * Copyright 2011 IBM Corp.
 */
#define pr_fmt(fmt)	"PCI: OF: " fmt

#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include "pci.h"

#ifdef CONFIG_PCI
void pci_set_of_node(struct pci_dev *dev)
{
	if (!dev->bus->dev.of_node)
		return;
	dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
						    dev->devfn);
	if (dev->dev.of_node)
		dev->dev.fwnode = &dev->dev.of_node->fwnode;
}

void pci_release_of_node(struct pci_dev *dev)
{
	of_node_put(dev->dev.of_node);
	dev->dev.of_node = NULL;
	dev->dev.fwnode = NULL;
}

void pci_set_bus_of_node(struct pci_bus *bus)
{
	struct device_node *node;

	if (bus->self == NULL) {
		node = pcibios_get_phb_of_node(bus);
	} else {
		node = of_node_get(bus->self->dev.of_node);
		if (node && of_property_read_bool(node, "external-facing"))
			bus->self->untrusted = true;
	}

	bus->dev.of_node = node;

	if (bus->dev.of_node)
		bus->dev.fwnode = &bus->dev.of_node->fwnode;
}

void pci_release_bus_of_node(struct pci_bus *bus)
{
	of_node_put(bus->dev.of_node);
	bus->dev.of_node = NULL;
	bus->dev.fwnode = NULL;
}

struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
{
	/* This should only be called for PHBs */
	if (WARN_ON(bus->self || bus->parent))
		return NULL;

	/*
	 * Look for a node pointer in either the intermediary device we
	 * create above the root bus or its own parent. Normally only
	 * the later is populated.
	 */
	if (bus->bridge->of_node)
		return of_node_get(bus->bridge->of_node);
	if (bus->bridge->parent && bus->bridge->parent->of_node)
		return of_node_get(bus->bridge->parent->of_node);
	return NULL;
}

struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
{
#ifdef CONFIG_IRQ_DOMAIN
	struct irq_domain *d;

	if (!bus->dev.of_node)
		return NULL;

	/* Start looking for a phandle to an MSI controller. */
	d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
	if (d)
		return d;

	/*
	 * If we don't have an msi-parent property, look for a domain
	 * directly attached to the host bridge.
	 */
	d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
	if (d)
		return d;

	return irq_find_host(bus->dev.of_node);
#else
	return NULL;
#endif
}

static inline int __of_pci_pci_compare(struct device_node *node,
				       unsigned int data)
{
	int devfn;

	devfn = of_pci_get_devfn(node);
	if (devfn < 0)
		return 0;

	return devfn == data;
}

struct device_node *of_pci_find_child_device(struct device_node *parent,
					     unsigned int devfn)
{
	struct device_node *node, *node2;

	for_each_child_of_node(parent, node) {
		if (__of_pci_pci_compare(node, devfn))
			return node;
		/*
		 * Some OFs create a parent node "multifunc-device" as
		 * a fake root for all functions of a multi-function
		 * device we go down them as well.
		 */
		if (of_node_name_eq(node, "multifunc-device")) {
			for_each_child_of_node(node, node2) {
				if (__of_pci_pci_compare(node2, devfn)) {
					of_node_put(node);
					return node2;
				}
			}
		}
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_child_device);

/**
 * of_pci_get_devfn() - Get device and function numbers for a device node
 * @np: device node
 *
 * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
 * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
 * and function numbers respectively. On error a negative error code is
 * returned.
 */
int of_pci_get_devfn(struct device_node *np)
{
	u32 reg[5];
	int error;

	error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
	if (error)
		return error;

	return (reg[0] >> 8) & 0xff;
}
EXPORT_SYMBOL_GPL(of_pci_get_devfn);

/**
 * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
 * @node: device node
 * @res: address to a struct resource to return the bus-range
 *
 * Returns 0 on success or a negative error-code on failure.
 */
int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
{
	u32 bus_range[2];
	int error;

	error = of_property_read_u32_array(node, "bus-range", bus_range,
					   ARRAY_SIZE(bus_range));
	if (error)
		return error;

	res->name = node->name;
	res->start = bus_range[0];
	res->end = bus_range[1];
	res->flags = IORESOURCE_BUS;

	return 0;
}
EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);

/**
 * This function will try to obtain the host bridge domain number by
 * finding a property called "linux,pci-domain" of the given device node.
 *
 * @node: device tree node with the domain information
 *
 * Returns the associated domain number from DT in the range [0-0xffff], or
 * a negative value if the required property is not found.
 */
int of_get_pci_domain_nr(struct device_node *node)
{
	u32 domain;
	int error;

	error = of_property_read_u32(node, "linux,pci-domain", &domain);
	if (error)
		return error;

	return (u16)domain;
}
EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);

/**
 * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 *                           is present and valid
 */
void of_pci_check_probe_only(void)
{
	u32 val;
	int ret;

	ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
	if (ret) {
		if (ret == -ENODATA || ret == -EOVERFLOW)
			pr_warn("linux,pci-probe-only without valid value, ignoring\n");
		return;
	}

	if (val)
		pci_add_flags(PCI_PROBE_ONLY);
	else
		pci_clear_flags(PCI_PROBE_ONLY);

	pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
}
EXPORT_SYMBOL_GPL(of_pci_check_probe_only);

/**
 * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
 *                                           host bridge resources from DT
 * @dev: host bridge device
 * @busno: bus number associated with the bridge root bus
 * @bus_max: maximum number of buses for this bridge
 * @resources: list where the range of resources will be added after DT parsing
 * @io_base: pointer to a variable that will contain on return the physical
 * address for the start of the I/O range. Can be NULL if the caller doesn't
 * expect I/O ranges to be present in the device tree.
 *
 * This function will parse the "ranges" property of a PCI host bridge device
 * node and setup the resource mapping based on its content. It is expected
 * that the property conforms with the Power ePAPR document.
 *
 * It returns zero if the range parsing has been successful or a standard error
 * value if it failed.
 */
static int devm_of_pci_get_host_bridge_resources(struct device *dev,
			unsigned char busno, unsigned char bus_max,
			struct list_head *resources,
			struct list_head *ib_resources,
			resource_size_t *io_base)
{
	struct device_node *dev_node = dev->of_node;
	struct resource *res, tmp_res;
	struct resource *bus_range;
	struct of_pci_range range;
	struct of_pci_range_parser parser;
	const char *range_type;
	int err;

	if (io_base)
		*io_base = (resource_size_t)OF_BAD_ADDR;

	bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
	if (!bus_range)
		return -ENOMEM;

	dev_info(dev, "host bridge %pOF ranges:\n", dev_node);

	err = of_pci_parse_bus_range(dev_node, bus_range);
	if (err) {
		bus_range->start = busno;
		bus_range->end = bus_max;
		bus_range->flags = IORESOURCE_BUS;
		dev_info(dev, "  No bus range found for %pOF, using %pR\n",
			 dev_node, bus_range);
	} else {
		if (bus_range->end > bus_range->start + bus_max)
			bus_range->end = bus_range->start + bus_max;
	}
	pci_add_resource(resources, bus_range);

	/* Check for ranges property */
	err = of_pci_range_parser_init(&parser, dev_node);
	if (err)
		goto failed;

	dev_dbg(dev, "Parsing ranges property...\n");
	for_each_of_pci_range(&parser, &range) {
		/* Read next ranges element */
		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
			range_type = "IO";
		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
			range_type = "MEM";
		else
			range_type = "err";
		dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
			 range_type, range.cpu_addr,
			 range.cpu_addr + range.size - 1, range.pci_addr);

		/*
		 * If we failed translation or got a zero-sized region
		 * then skip this range
		 */
		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
			continue;

		err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
		if (err)
			continue;

		res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
		if (!res) {
			err = -ENOMEM;
			goto failed;
		}

		if (resource_type(res) == IORESOURCE_IO) {
			if (!io_base) {
				dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
					dev_node);
				err = -EINVAL;
				goto failed;
			}
			if (*io_base != (resource_size_t)OF_BAD_ADDR)
				dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
					 dev_node);
			*io_base = range.cpu_addr;
		}

		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
	}

	/* Check for dma-ranges property */
	if (!ib_resources)
		return 0;
	err = of_pci_dma_range_parser_init(&parser, dev_node);
	if (err)
		return 0;

	dev_dbg(dev, "Parsing dma-ranges property...\n");
	for_each_of_pci_range(&parser, &range) {
		struct resource_entry *entry;
		/*
		 * If we failed translation or got a zero-sized region
		 * then skip this range
		 */
		if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) ||
		    range.cpu_addr == OF_BAD_ADDR || range.size == 0)
			continue;

		dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
			 "IB MEM", range.cpu_addr,
			 range.cpu_addr + range.size - 1, range.pci_addr);


		err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
		if (err)
			continue;

		res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
		if (!res) {
			err = -ENOMEM;
			goto failed;
		}

		/* Keep the resource list sorted */
		resource_list_for_each_entry(entry, ib_resources)
			if (entry->res->start > res->start)
				break;

		pci_add_resource_offset(&entry->node, res,
					res->start - range.pci_addr);
	}

	return 0;

failed:
	pci_free_resource_list(resources);
	return err;
}

#if IS_ENABLED(CONFIG_OF_IRQ)
/**
 * of_irq_parse_pci - Resolve the interrupt for a PCI device
 * @pdev:       the device whose interrupt is to be resolved
 * @out_irq:    structure of_phandle_args filled by this function
 *
 * This function resolves the PCI interrupt for a given PCI device. If a
 * device-node exists for a given pci_dev, it will use normal OF tree
 * walking. If not, it will implement standard swizzling and walk up the
 * PCI tree until an device-node is found, at which point it will finish
 * resolving using the OF tree walking.
 */
static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
{
	struct device_node *dn, *ppnode;
	struct pci_dev *ppdev;
	__be32 laddr[3];
	u8 pin;
	int rc;

	/*
	 * Check if we have a device node, if yes, fallback to standard
	 * device tree parsing
	 */
	dn = pci_device_to_OF_node(pdev);
	if (dn) {
		rc = of_irq_parse_one(dn, 0, out_irq);
		if (!rc)
			return rc;
	}

	/*
	 * Ok, we don't, time to have fun. Let's start by building up an
	 * interrupt spec.  we assume #interrupt-cells is 1, which is standard
	 * for PCI. If you do different, then don't use that routine.
	 */
	rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
	if (rc != 0)
		goto err;
	/* No pin, exit with no error message. */
	if (pin == 0)
		return -ENODEV;

	/* Now we walk up the PCI tree */
	for (;;) {
		/* Get the pci_dev of our parent */
		ppdev = pdev->bus->self;

		/* Ouch, it's a host bridge... */
		if (ppdev == NULL) {
			ppnode = pci_bus_to_OF_node(pdev->bus);

			/* No node for host bridge ? give up */
			if (ppnode == NULL) {
				rc = -EINVAL;
				goto err;
			}
		} else {
			/* We found a P2P bridge, check if it has a node */
			ppnode = pci_device_to_OF_node(ppdev);
		}

		/*
		 * Ok, we have found a parent with a device-node, hand over to
		 * the OF parsing code.
		 * We build a unit address from the linux device to be used for
		 * resolution. Note that we use the linux bus number which may
		 * not match your firmware bus numbering.
		 * Fortunately, in most cases, interrupt-map-mask doesn't
		 * include the bus number as part of the matching.
		 * You should still be careful about that though if you intend
		 * to rely on this function (you ship a firmware that doesn't
		 * create device nodes for all PCI devices).
		 */
		if (ppnode)
			break;

		/*
		 * We can only get here if we hit a P2P bridge with no node;
		 * let's do standard swizzling and try again
		 */
		pin = pci_swizzle_interrupt_pin(pdev, pin);
		pdev = ppdev;
	}

	out_irq->np = ppnode;
	out_irq->args_count = 1;
	out_irq->args[0] = pin;
	laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
	laddr[1] = laddr[2] = cpu_to_be32(0);
	rc = of_irq_parse_raw(laddr, out_irq);
	if (rc)
		goto err;
	return 0;
err:
	if (rc == -ENOENT) {
		dev_warn(&pdev->dev,
			"%s: no interrupt-map found, INTx interrupts not available\n",
			__func__);
		pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
			__func__);
	} else {
		dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
	}
	return rc;
}

/**
 * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
 * @dev: The PCI device needing an IRQ
 * @slot: PCI slot number; passed when used as map_irq callback. Unused
 * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
 *
 * @slot and @pin are unused, but included in the function so that this
 * function can be used directly as the map_irq callback to
 * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
 */
int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
{
	struct of_phandle_args oirq;
	int ret;

	ret = of_irq_parse_pci(dev, &oirq);
	if (ret)
		return 0; /* Proper return code 0 == NO_IRQ */

	return irq_create_of_mapping(&oirq);
}
EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
#endif	/* CONFIG_OF_IRQ */

int pci_parse_request_of_pci_ranges(struct device *dev,
				    struct list_head *resources,
				    struct list_head *ib_resources,
				    struct resource **bus_range)
{
	int err, res_valid = 0;
	resource_size_t iobase;
	struct resource_entry *win, *tmp;

	INIT_LIST_HEAD(resources);
	if (ib_resources)
		INIT_LIST_HEAD(ib_resources);
	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources,
						    ib_resources, &iobase);
	if (err)
		return err;

	err = devm_request_pci_bus_resources(dev, resources);
	if (err)
		goto out_release_res;

	resource_list_for_each_entry_safe(win, tmp, resources) {
		struct resource *res = win->res;

		switch (resource_type(res)) {
		case IORESOURCE_IO:
			err = devm_pci_remap_iospace(dev, res, iobase);
			if (err) {
				dev_warn(dev, "error %d: failed to map resource %pR\n",
					 err, res);
				resource_list_destroy_entry(win);
			}
			break;
		case IORESOURCE_MEM:
			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
			break;
		case IORESOURCE_BUS:
			if (bus_range)
				*bus_range = res;
			break;
		}
	}

	if (res_valid)
		return 0;

	dev_err(dev, "non-prefetchable memory resource required\n");
	err = -EINVAL;

 out_release_res:
	pci_free_resource_list(resources);
	return err;
}
EXPORT_SYMBOL_GPL(pci_parse_request_of_pci_ranges);

#endif /* CONFIG_PCI */

/**
 * This function will try to find the limitation of link speed by finding
 * a property called "max-link-speed" of the given device node.
 *
 * @node: device tree node with the max link speed information
 *
 * Returns the associated max link speed from DT, or a negative value if the
 * required property is not found or is invalid.
 */
int of_pci_get_max_link_speed(struct device_node *node)
{
	u32 max_link_speed;

	if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
	    max_link_speed > 4)
		return -EINVAL;

	return max_link_speed;
}
EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
Commit	Line	Data
736759ef	1	// SPDX-License-Identifier: GPL-2.0+
98d9f30c BH	2	/*
	3	* PCI <-> OF mapping helpers
	4	*
	5	* Copyright 2011 IBM Corp.
98d9f30c	6	*/
4670d610	7	#define pr_fmt(fmt) "PCI: OF: " fmt
98d9f30c	8
b165e2b6	9	#include <linux/irqdomain.h>
98d9f30c BH	10	#include <linux/kernel.h>
	11	#include <linux/pci.h>
	12	#include <linux/of.h>
c8d17588	13	#include <linux/of_irq.h>
4670d610	14	#include <linux/of_address.h>
98d9f30c BH	15	#include <linux/of_pci.h>
	16	#include "pci.h"
	17
40e5d614	18	#ifdef CONFIG_PCI
98d9f30c BH	19	void pci_set_of_node(struct pci_dev *dev)
	20	{
	21	if (!dev->bus->dev.of_node)
	22	return;
	23	dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
	24	dev->devfn);
59b099a6 JPB	25	if (dev->dev.of_node)
59b099a6 JPB	26	dev->dev.fwnode = &dev->dev.of_node->fwnode;
98d9f30c BH	27	}
	28
	29	void pci_release_of_node(struct pci_dev *dev)
	30	{
	31	of_node_put(dev->dev.of_node);
	32	dev->dev.of_node = NULL;
59b099a6	33	dev->dev.fwnode = NULL;
98d9f30c BH	34	}
	35
	36	void pci_set_bus_of_node(struct pci_bus *bus)
	37	{
9cb30a71 JPB	38	struct device_node *node;
	39
	40	if (bus->self == NULL) {
	41	node = pcibios_get_phb_of_node(bus);
	42	} else {
	43	node = of_node_get(bus->self->dev.of_node);
	44	if (node && of_property_read_bool(node, "external-facing"))
	45	bus->self->untrusted = true;
	46	}
59b099a6	47
9cb30a71	48	bus->dev.of_node = node;
59b099a6 JPB	49
	50	if (bus->dev.of_node)
	51	bus->dev.fwnode = &bus->dev.of_node->fwnode;
98d9f30c BH	52	}
	53
	54	void pci_release_bus_of_node(struct pci_bus *bus)
	55	{
	56	of_node_put(bus->dev.of_node);
	57	bus->dev.of_node = NULL;
59b099a6	58	bus->dev.fwnode = NULL;
98d9f30c BH	59	}
	60
	61	struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
	62	{
	63	/* This should only be called for PHBs */
	64	if (WARN_ON(bus->self \|\| bus->parent))
	65	return NULL;
	66
4670d610 RH	67	/*
	68	* Look for a node pointer in either the intermediary device we
	69	* create above the root bus or its own parent. Normally only
98d9f30c BH	70	* the later is populated.
	71	*/
	72	if (bus->bridge->of_node)
	73	return of_node_get(bus->bridge->of_node);
69566dd8	74	if (bus->bridge->parent && bus->bridge->parent->of_node)
98d9f30c BH	75	return of_node_get(bus->bridge->parent->of_node);
	76	return NULL;
	77	}
b165e2b6 MZ	78
	79	struct irq_domain pci_host_bridge_of_msi_domain(struct pci_bus bus)
	80	{
	81	#ifdef CONFIG_IRQ_DOMAIN
b165e2b6 MZ	82	struct irq_domain *d;
	83
	84	if (!bus->dev.of_node)
	85	return NULL;
	86
	87	/* Start looking for a phandle to an MSI controller. */
c8d17588 MZ	88	d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
	89	if (d)
	90	return d;
471c931c MZ	91
	92	/*
	93	* If we don't have an msi-parent property, look for a domain
	94	* directly attached to the host bridge.
	95	*/
c8d17588	96	d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
b165e2b6 MZ	97	if (d)
	98	return d;
	99
c8d17588	100	return irq_find_host(bus->dev.of_node);
b165e2b6 MZ	101	#else
	102	return NULL;
	103	#endif
	104	}
4670d610	105
4670d610 RH	106	static inline int __of_pci_pci_compare(struct device_node *node,
	107	unsigned int data)
	108	{
	109	int devfn;
	110
	111	devfn = of_pci_get_devfn(node);
	112	if (devfn < 0)
	113	return 0;
	114
	115	return devfn == data;
	116	}
	117
	118	struct device_node of_pci_find_child_device(struct device_node parent,
	119	unsigned int devfn)
	120	{
	121	struct device_node node, node2;
	122
	123	for_each_child_of_node(parent, node) {
	124	if (__of_pci_pci_compare(node, devfn))
	125	return node;
	126	/*
	127	* Some OFs create a parent node "multifunc-device" as
	128	* a fake root for all functions of a multi-function
	129	* device we go down them as well.
	130	*/
83a50d3a	131	if (of_node_name_eq(node, "multifunc-device")) {
4670d610 RH	132	for_each_child_of_node(node, node2) {
	133	if (__of_pci_pci_compare(node2, devfn)) {
	134	of_node_put(node);
	135	return node2;
	136	}
	137	}
	138	}
	139	}
	140	return NULL;
	141	}
	142	EXPORT_SYMBOL_GPL(of_pci_find_child_device);
	143
	144	/**
	145	* of_pci_get_devfn() - Get device and function numbers for a device node
	146	* @np: device node
	147	*
	148	* Parses a standard 5-cell PCI resource and returns an 8-bit value that can
	149	* be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
	150	* and function numbers respectively. On error a negative error code is
	151	* returned.
	152	*/
	153	int of_pci_get_devfn(struct device_node *np)
	154	{
	155	u32 reg[5];
	156	int error;
	157
	158	error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
	159	if (error)
	160	return error;
	161
	162	return (reg[0] >> 8) & 0xff;
	163	}
	164	EXPORT_SYMBOL_GPL(of_pci_get_devfn);
	165
	166	/**
	167	* of_pci_parse_bus_range() - parse the bus-range property of a PCI device
	168	* @node: device node
	169	* @res: address to a struct resource to return the bus-range
	170	*
	171	* Returns 0 on success or a negative error-code on failure.
	172	*/
	173	int of_pci_parse_bus_range(struct device_node node, struct resource res)
	174	{
	175	u32 bus_range[2];
	176	int error;
	177
	178	error = of_property_read_u32_array(node, "bus-range", bus_range,
	179	ARRAY_SIZE(bus_range));
	180	if (error)
	181	return error;
	182
	183	res->name = node->name;
	184	res->start = bus_range[0];
	185	res->end = bus_range[1];
	186	res->flags = IORESOURCE_BUS;
	187
	188	return 0;
	189	}
	190	EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
	191
	192	/**
	193	* This function will try to obtain the host bridge domain number by
	194	* finding a property called "linux,pci-domain" of the given device node.
	195	*
196	* @node: device tree node with the domain information
197	*
198	* Returns the associated domain number from DT in the range [0-0xffff], or
199	* a negative value if the required property is not found.
200	*/
201	int of_get_pci_domain_nr(struct device_node *node)
202	{
203	u32 domain;
204	int error;
205
206	error = of_property_read_u32(node, "linux,pci-domain", &domain);
207	if (error)
208	return error;
209
210	return (u16)domain;
211	}
212	EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
213
4670d610 RH	214	/**
	215	* of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
	216	* is present and valid
	217	*/
	218	void of_pci_check_probe_only(void)
	219	{
	220	u32 val;
	221	int ret;
	222
	223	ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
	224	if (ret) {
	225	if (ret == -ENODATA \|\| ret == -EOVERFLOW)
	226	pr_warn("linux,pci-probe-only without valid value, ignoring\n");
	227	return;
	228	}
	229
	230	if (val)
	231	pci_add_flags(PCI_PROBE_ONLY);
	232	else
	233	pci_clear_flags(PCI_PROBE_ONLY);
	234
	235	pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
	236	}
	237	EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
	238
4670d610	239	/**
5bd51b35 JK	240	* devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
5bd51b35 JK	241	* host bridge resources from DT
055f87a2	242	* @dev: host bridge device
4670d610 RH	243	* @busno: bus number associated with the bridge root bus
	244	* @bus_max: maximum number of buses for this bridge
	245	* @resources: list where the range of resources will be added after DT parsing
	246	* @io_base: pointer to a variable that will contain on return the physical
	247	* address for the start of the I/O range. Can be NULL if the caller doesn't
	248	* expect I/O ranges to be present in the device tree.
	249	*
4670d610 RH	250	* This function will parse the "ranges" property of a PCI host bridge device
	251	* node and setup the resource mapping based on its content. It is expected
	252	* that the property conforms with the Power ePAPR document.
	253	*
	254	* It returns zero if the range parsing has been successful or a standard error
	255	* value if it failed.
	256	*/
3b55809c	257	static int devm_of_pci_get_host_bridge_resources(struct device *dev,
4670d610	258	unsigned char busno, unsigned char bus_max,
331f6345 RH	259	struct list_head *resources,
	260	struct list_head *ib_resources,
	261	resource_size_t *io_base)
4670d610	262	{
055f87a2	263	struct device_node *dev_node = dev->of_node;
93c9a7f8	264	struct resource *res, tmp_res;
4670d610 RH	265	struct resource *bus_range;
	266	struct of_pci_range range;
	267	struct of_pci_range_parser parser;
331f6345	268	const char *range_type;
4670d610 RH	269	int err;
	270
	271	if (io_base)
	272	*io_base = (resource_size_t)OF_BAD_ADDR;
	273
5bd51b35	274	bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
4670d610 RH	275	if (!bus_range)
	276	return -ENOMEM;
	277
d9c5d5ac	278	dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
4670d610	279
126b7de6	280	err = of_pci_parse_bus_range(dev_node, bus_range);
4670d610 RH	281	if (err) {
	282	bus_range->start = busno;
	283	bus_range->end = bus_max;
	284	bus_range->flags = IORESOURCE_BUS;
d9c5d5ac JK	285	dev_info(dev, " No bus range found for %pOF, using %pR\n",
d9c5d5ac JK	286	dev_node, bus_range);
4670d610 RH	287	} else {
	288	if (bus_range->end > bus_range->start + bus_max)
	289	bus_range->end = bus_range->start + bus_max;
	290	}
	291	pci_add_resource(resources, bus_range);
	292
	293	/* Check for ranges property */
126b7de6	294	err = of_pci_range_parser_init(&parser, dev_node);
4670d610	295	if (err)
5bd51b35	296	goto failed;
4670d610	297
d9c5d5ac	298	dev_dbg(dev, "Parsing ranges property...\n");
4670d610 RH	299	for_each_of_pci_range(&parser, &range) {
	300	/* Read next ranges element */
	301	if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
331f6345	302	range_type = "IO";
4670d610	303	else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
331f6345	304	range_type = "MEM";
4670d610	305	else
331f6345 RH	306	range_type = "err";
331f6345 RH	307	dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
d9c5d5ac JK	308	range_type, range.cpu_addr,
d9c5d5ac JK	309	range.cpu_addr + range.size - 1, range.pci_addr);
4670d610 RH	310
	311	/*
	312	* If we failed translation or got a zero-sized region
	313	* then skip this range
	314	*/
	315	if (range.cpu_addr == OF_BAD_ADDR \|\| range.size == 0)
	316	continue;
	317
93c9a7f8 JK	318	err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
	319	if (err)
	320	continue;
	321
	322	res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
4670d610 RH	323	if (!res) {
4670d610 RH	324	err = -ENOMEM;
5bd51b35	325	goto failed;
4670d610 RH	326	}
4670d610 RH	327
4670d610 RH	328	if (resource_type(res) == IORESOURCE_IO) {
4670d610 RH	329	if (!io_base) {
d9c5d5ac	330	dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
126b7de6	331	dev_node);
4670d610	332	err = -EINVAL;
5bd51b35	333	goto failed;
4670d610 RH	334	}
4670d610 RH	335	if (*io_base != (resource_size_t)OF_BAD_ADDR)
d9c5d5ac JK	336	dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
d9c5d5ac JK	337	dev_node);
4670d610 RH	338	*io_base = range.cpu_addr;
	339	}
	340
	341	pci_add_resource_offset(resources, res, res->start - range.pci_addr);
	342	}
	343
331f6345 RH	344	/* Check for dma-ranges property */
	345	if (!ib_resources)
	346	return 0;
	347	err = of_pci_dma_range_parser_init(&parser, dev_node);
	348	if (err)
	349	return 0;
	350
	351	dev_dbg(dev, "Parsing dma-ranges property...\n");
	352	for_each_of_pci_range(&parser, &range) {
	353	struct resource_entry *entry;
	354	/*
	355	* If we failed translation or got a zero-sized region
	356	* then skip this range
	357	*/
	358	if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) \|\|
	359	range.cpu_addr == OF_BAD_ADDR \|\| range.size == 0)
	360	continue;
	361
	362	dev_info(dev, " %6s %#012llx..%#012llx -> %#012llx\n",
	363	"IB MEM", range.cpu_addr,
	364	range.cpu_addr + range.size - 1, range.pci_addr);
	365
	366
	367	err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
	368	if (err)
	369	continue;
	370
	371	res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
	372	if (!res) {
	373	err = -ENOMEM;
	374	goto failed;
	375	}
	376
	377	/* Keep the resource list sorted */
	378	resource_list_for_each_entry(entry, ib_resources)
	379	if (entry->res->start > res->start)
	380	break;
	381
	382	pci_add_resource_offset(&entry->node, res,
	383	res->start - range.pci_addr);
	384	}
	385
4670d610 RH	386	return 0;
4670d610 RH	387
5bd51b35	388	failed:
4670d610 RH	389	pci_free_resource_list(resources);
	390	return err;
	391	}
4670d610	392
4670d610 RH	393	#if IS_ENABLED(CONFIG_OF_IRQ)
	394	/**
	395	* of_irq_parse_pci - Resolve the interrupt for a PCI device
	396	* @pdev: the device whose interrupt is to be resolved
b071c1fd	397	* @out_irq: structure of_phandle_args filled by this function
4670d610 RH	398	*
	399	* This function resolves the PCI interrupt for a given PCI device. If a
	400	* device-node exists for a given pci_dev, it will use normal OF tree
	401	* walking. If not, it will implement standard swizzling and walk up the
	402	* PCI tree until an device-node is found, at which point it will finish
	403	* resolving using the OF tree walking.
	404	*/
7e297843	405	static int of_irq_parse_pci(const struct pci_dev pdev, struct of_phandle_args out_irq)
4670d610 RH	406	{
	407	struct device_node dn, ppnode;
	408	struct pci_dev *ppdev;
	409	__be32 laddr[3];
	410	u8 pin;
	411	int rc;
	412
	413	/*
	414	* Check if we have a device node, if yes, fallback to standard
	415	* device tree parsing
	416	*/
	417	dn = pci_device_to_OF_node(pdev);
	418	if (dn) {
	419	rc = of_irq_parse_one(dn, 0, out_irq);
	420	if (!rc)
	421	return rc;
	422	}
	423
	424	/*
	425	* Ok, we don't, time to have fun. Let's start by building up an
	426	* interrupt spec. we assume #interrupt-cells is 1, which is standard
	427	* for PCI. If you do different, then don't use that routine.
	428	*/
	429	rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
	430	if (rc != 0)
	431	goto err;
	432	/* No pin, exit with no error message. */
	433	if (pin == 0)
	434	return -ENODEV;
	435
	436	/* Now we walk up the PCI tree */
	437	for (;;) {
	438	/* Get the pci_dev of our parent */
	439	ppdev = pdev->bus->self;
	440
	441	/* Ouch, it's a host bridge... */
	442	if (ppdev == NULL) {
	443	ppnode = pci_bus_to_OF_node(pdev->bus);
	444
	445	/* No node for host bridge ? give up */
	446	if (ppnode == NULL) {
	447	rc = -EINVAL;
	448	goto err;
	449	}
	450	} else {
	451	/* We found a P2P bridge, check if it has a node */
	452	ppnode = pci_device_to_OF_node(ppdev);
	453	}
	454
	455	/*
	456	* Ok, we have found a parent with a device-node, hand over to
	457	* the OF parsing code.
	458	* We build a unit address from the linux device to be used for
	459	* resolution. Note that we use the linux bus number which may
	460	* not match your firmware bus numbering.
	461	* Fortunately, in most cases, interrupt-map-mask doesn't
	462	* include the bus number as part of the matching.
	463	* You should still be careful about that though if you intend
	464	* to rely on this function (you ship a firmware that doesn't
	465	* create device nodes for all PCI devices).
	466	*/
	467	if (ppnode)
	468	break;
	469
470	/*
471	* We can only get here if we hit a P2P bridge with no node;
472	* let's do standard swizzling and try again
473	*/
474	pin = pci_swizzle_interrupt_pin(pdev, pin);
475	pdev = ppdev;
476	}
477
478	out_irq->np = ppnode;
479	out_irq->args_count = 1;
480	out_irq->args[0] = pin;
481	laddr[0] = cpu_to_be32((pdev->bus->number << 16) \| (pdev->devfn << 8));
482	laddr[1] = laddr[2] = cpu_to_be32(0);
483	rc = of_irq_parse_raw(laddr, out_irq);
484	if (rc)
485	goto err;
486	return 0;
487	err:
488	if (rc == -ENOENT) {
489	dev_warn(&pdev->dev,
490	"%s: no interrupt-map found, INTx interrupts not available\n",
491	__func__);
492	pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
493	__func__);
494	} else {
495	dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
496	}
497	return rc;
498	}
4670d610 RH	499
	500	/**
	501	* of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
	502	* @dev: The PCI device needing an IRQ
	503	* @slot: PCI slot number; passed when used as map_irq callback. Unused
	504	* @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
	505	*
	506	* @slot and @pin are unused, but included in the function so that this
	507	* function can be used directly as the map_irq callback to
	508	* pci_assign_irq() and struct pci_host_bridge.map_irq pointer
	509	*/
	510	int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
	511	{
	512	struct of_phandle_args oirq;
	513	int ret;
	514
	515	ret = of_irq_parse_pci(dev, &oirq);
	516	if (ret)
	517	return 0; /* Proper return code 0 == NO_IRQ */
	518
	519	return irq_create_of_mapping(&oirq);
	520	}
	521	EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
	522	#endif /* CONFIG_OF_IRQ */
c7f75aec	523
3a8f77e4 CP	524	int pci_parse_request_of_pci_ranges(struct device *dev,
3a8f77e4 CP	525	struct list_head *resources,
331f6345	526	struct list_head *ib_resources,
3a8f77e4 CP	527	struct resource **bus_range)
	528	{
	529	int err, res_valid = 0;
3a8f77e4 CP	530	resource_size_t iobase;
	531	struct resource_entry win, tmp;
	532
	533	INIT_LIST_HEAD(resources);
331f6345 RH	534	if (ib_resources)
331f6345 RH	535	INIT_LIST_HEAD(ib_resources);
5bd51b35	536	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources,
331f6345	537	ib_resources, &iobase);
3a8f77e4 CP	538	if (err)
	539	return err;
	540
	541	err = devm_request_pci_bus_resources(dev, resources);
	542	if (err)
	543	goto out_release_res;
	544
	545	resource_list_for_each_entry_safe(win, tmp, resources) {
	546	struct resource *res = win->res;
	547
	548	switch (resource_type(res)) {
	549	case IORESOURCE_IO:
a5fb9fb0	550	err = devm_pci_remap_iospace(dev, res, iobase);
3a8f77e4 CP	551	if (err) {
	552	dev_warn(dev, "error %d: failed to map resource %pR\n",
	553	err, res);
	554	resource_list_destroy_entry(win);
	555	}
	556	break;
	557	case IORESOURCE_MEM:
	558	res_valid \|= !(res->flags & IORESOURCE_PREFETCH);
	559	break;
	560	case IORESOURCE_BUS:
	561	if (bus_range)
	562	*bus_range = res;
	563	break;
	564	}
	565	}
	566
	567	if (res_valid)
	568	return 0;
	569
	570	dev_err(dev, "non-prefetchable memory resource required\n");
	571	err = -EINVAL;
	572
	573	out_release_res:
	574	pci_free_resource_list(resources);
	575	return err;
	576	}
65991f43	577	EXPORT_SYMBOL_GPL(pci_parse_request_of_pci_ranges);
c7f75aec	578
40e5d614 KVA	579	#endif /* CONFIG_PCI */
	580
	581	/**
	582	* This function will try to find the limitation of link speed by finding
	583	* a property called "max-link-speed" of the given device node.
	584	*
	585	* @node: device tree node with the max link speed information
	586	*
	587	* Returns the associated max link speed from DT, or a negative value if the
	588	* required property is not found or is invalid.
	589	*/
	590	int of_pci_get_max_link_speed(struct device_node *node)
	591	{
	592	u32 max_link_speed;
	593
	594	if (of_property_read_u32(node, "max-link-speed", &max_link_speed) \|\|
	595	max_link_speed > 4)
	596	return -EINVAL;
	597
	598	return max_link_speed;
	599	}
	600	EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);