[PATCH v10 08/10] OF: PCI: Add support for parsing PCI host bridge resources from DT
From: Lorenzo Pieralisi <hidden>
Date: 2014-09-09 13:35:55
Also in:
linux-arch, linux-devicetree, linux-pci, lkml
On Mon, Sep 08, 2014 at 02:54:30PM +0100, Liviu Dudau wrote:
quoted hunk ↗ jump to hunk
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@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Grant Likely <redacted> Cc: Rob Herring <robh+dt@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> --- drivers/of/of_pci.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of_pci.h | 11 ++++++ 2 files changed, 113 insertions(+)diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c index a107edb..36701da 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)@@ -123,6 +125,106 @@ int of_pci_get_domain_nr(struct device_node *node, bool allocate_if_missing) } EXPORT_SYMBOL_GPL(of_pci_get_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. + * + * 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.
You should also define what it returns and when.
+ *
+ */
+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;
+
+ 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);This means that eg in the PCI generic host controller I cannot "filter" the bus resource, unless I remove it, "filter" it, and add it again. I certainly can't filter a resource that has been already added without removing it first. Thoughts ?
+
+ /* 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) {
+ kfree(res);You might want to add a label to free res to make things more uniform.
+ goto parse_failed;
+ }
+
+ if (resource_type(res) == IORESOURCE_IO) {
+ if (*io_base)You do not zero io_base in the first place so you should ask the API user to do that. Is 0 a valid value BTW ? If it is you've got to resort to something else to detect multiple IO resources. Lorenzo