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

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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: Liviu Dudau <Liviu.Dudau@arm.com>
[make io_base parameter optional]
Signed-off-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Bjorn 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>
This commit is contained in:
Liviu Dudau 2014-09-29 15:29:28 +01:00 committed by Bjorn Helgaas
parent 41e5c0f81d
commit cbe4097f8a
2 changed files with 123 additions and 0 deletions
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117
drivers/of/of_pci.c
View file

@ -1,7 +1,9 @@
#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);

6
include/linux/of_pci.h
View file

@ -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);