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.
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx>
[make io_base parameter optional]
Signed-off-by: Robert Richter <rrichter@xxxxxxxxxx>
---
drivers/of/of_pci.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_pci.h | 11 +++++
2 files changed, 126 insertions(+)
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 82d172f..c2285aa 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -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 +116,119 @@ int of_get_pci_domain_nr(struct device_node *node)
}
EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
+/**
+ * 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 busses 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 callers 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);
+
#ifdef CONFIG_PCI_MSI
static LIST_HEAD(of_pci_msi_chip_list);
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 71062e9..9ff818a 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -16,6 +16,10 @@ int of_pci_get_devfn(struct device_node *np);
int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
int of_get_pci_domain_nr(struct device_node *node);
+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);
+
#else
static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
{
@@ -50,6 +54,13 @@ of_get_pci_domain_nr(struct device_node *node)
{
return -1;
}
+
+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);
+{
+ return -EINVAL;
+}
#endif
#if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
--
2.1.0
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