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Commit cbe4097f authored by Liviu Dudau's avatar Liviu Dudau Committed by Bjorn Helgaas
Browse files

of/pci: Add support for parsing PCI host bridge resources from DT 



Provide a function to parse the PCI DT ranges that can be used to create a
pci_host_bridge structure together with its associated bus.

Signed-off-by: default avatarLiviu Dudau <Liviu.Dudau@arm.com>
[make io_base parameter optional]
Signed-off-by: default avatarRobert Richter <rrichter@cavium.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
parent 41e5c0f8

drivers/of/of_pci.c

+117 −0
Original line number Diff line number Diff line 
#include <linux/kernel.h>

#include <linux/export.h>

#include <linux/of.h>

#include <linux/of_address.h>

#include <linux/of_pci.h>

#include <linux/slab.h>



static inline int __of_pci_pci_compare(struct device_node *node,

				       unsigned int data)
@@ -114,6 +116,121 @@ int of_get_pci_domain_nr(struct device_node *node) 
}

EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);



#if defined(CONFIG_OF_ADDRESS)

/**

 * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT

 * @dev: device node of the host bridge having the range property

 * @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 IO ranges to be present in the device tree.

 *

 * It is the caller's job to free the @resources list.

 *

 * 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.

 */

int of_pci_get_host_bridge_resources(struct device_node *dev,

			unsigned char busno, unsigned char bus_max,

			struct list_head *resources, resource_size_t *io_base)

{

	struct resource *res;

	struct resource *bus_range;

	struct of_pci_range range;

	struct of_pci_range_parser parser;

	char range_type[4];

	int err;



	if (io_base)

		*io_base = (resource_size_t)OF_BAD_ADDR;



	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);

	if (!bus_range)

		return -ENOMEM;



	pr_info("PCI host bridge %s ranges:\n", dev->full_name);



	err = of_pci_parse_bus_range(dev, bus_range);

	if (err) {

		bus_range->start = busno;

		bus_range->end = bus_max;

		bus_range->flags = IORESOURCE_BUS;

		pr_info("  No bus range found for %s, using %pR\n",

			dev->full_name, 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);

	if (err)

		goto parse_failed;



	pr_debug("Parsing ranges property...\n");

	for_each_of_pci_range(&parser, &range) {

		/* Read next ranges element */

		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)

			snprintf(range_type, 4, " IO");

		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)

			snprintf(range_type, 4, "MEM");

		else

			snprintf(range_type, 4, "err");

		pr_info("  %s %#010llx..%#010llx -> %#010llx\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;



		res = kzalloc(sizeof(struct resource), GFP_KERNEL);

		if (!res) {

			err = -ENOMEM;

			goto parse_failed;

		}



		err = of_pci_range_to_resource(&range, dev, res);

		if (err)

			goto conversion_failed;



		if (resource_type(res) == IORESOURCE_IO) {

			if (!io_base) {

				pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",

					dev->full_name);

				err = -EINVAL;

				goto conversion_failed;

			}

			if (*io_base != (resource_size_t)OF_BAD_ADDR)

				pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",

					dev->full_name);

			*io_base = range.cpu_addr;

		}



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

	}



	return 0;



conversion_failed:

	kfree(res);

parse_failed:

	pci_free_resource_list(resources);

	return err;

}

EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);

#endif /* CONFIG_OF_ADDRESS */



#ifdef CONFIG_PCI_MSI



static LIST_HEAD(of_pci_msi_chip_list);

include/linux/of_pci.h

+6 −0
Original line number Diff line number Diff line
@@ -52,6 +52,12 @@ of_get_pci_domain_nr(struct device_node *node) 
}

#endif



#if defined(CONFIG_OF_ADDRESS)

int of_pci_get_host_bridge_resources(struct device_node *dev,

			unsigned char busno, unsigned char bus_max,

			struct list_head *resources, resource_size_t *io_base);

#endif



#if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)

int of_pci_msi_chip_add(struct msi_chip *chip);

void of_pci_msi_chip_remove(struct msi_chip *chip);