On Thursday 27 February 2014 13:06:42 Liviu Dudau wrote:
Several platforms use a rather generic version of parsing the device tree to find the host bridge ranges. Move the common code into the generic PCI code and use it to create a pci_host_bridge structure that can be used by arch code.
Based on early attempts by Andrew Murray to unify the code. Used powerpc and microblaze PCI code as starting point.
Signed-off-by: Liviu Dudau Liviu.Dudau@arm.com
Please add Benjamin Herrenschmidt to Cc here, I think it would be helpful to get his input so we can make this work on powerpc as well.
diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c index 06ace62..feb8436 100644 --- a/drivers/pci/host-bridge.c +++ b/drivers/pci/host-bridge.c @@ -6,9 +6,13 @@ #include <linux/init.h> #include <linux/pci.h> #include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_pci.h> #include "pci.h" +static int domain_nr;
For correctness, I think you want an 'atomic_t' here and use atomic_inc_return() to get a new value.
static struct pci_bus *find_pci_root_bus(struct pci_bus *bus) { while (bus->parent) @@ -91,3 +95,133 @@ void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res, res->end = region->end + offset; } EXPORT_SYMBOL(pcibios_bus_to_resource);
+/**
- pci_host_bridge_of_get_ranges - Parse PCI host bridge resources from DT
- @dev: device node of the host bridge having the range property
- @resources: list where the range of resources will be added after DT parsing
- @io_base: pointer to a variable that will contain the physical address for
- the start of the I/O range.
- If this function returns an error then the @resources list will be freed.
- 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.
- Each architecture is then offered the chance of applying their own
- filtering of pci_host_bridge_windows based on their own restrictions by
- calling pcibios_fixup_bridge_ranges(). The filtered list of windows
- can then be used when creating a pci_host_bridge structure.
- */
+static int pci_host_bridge_of_get_ranges(struct device_node *dev,
struct list_head *resources, resource_size_t *io_base)
+{
- struct resource *res;
- struct of_pci_range range;
- struct of_pci_range_parser parser;
- int err;
- pr_info("PCI host bridge %s ranges:\n", dev->full_name);
- /* Check for ranges property */
- err = of_pci_range_parser_init(&parser, dev);
- if (err)
return err;
- pr_debug("Parsing ranges property...\n");
- for_each_of_pci_range(&parser, &range) {
/* Read next ranges element */
pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ",
range.pci_space, range.pci_addr);
pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
range.cpu_addr, range.size);
/*
* 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 bridge_ranges_nomem;
}
of_pci_range_to_resource(&range, dev, res);
if (resource_type(res) == IORESOURCE_IO)
*io_base = range.cpu_addr;
pci_add_resource_offset(resources, res,
res->start - range.pci_addr);
- }
This is not the correct resource for I/O space at all. Please talk to Will, I've been over this with him in detail and he probably understands it now. I assume you are both working in the same building.
Since this is common PCI code, you could also decide to open-code the pci_add_resource_offset() function. If you don't do that, I think you have a memory leak for the resources that you can avoid by allocating the resource and pci_host_bridge_window structures together with a single kzalloc.
- /* Apply architecture specific fixups for the ranges */
- pcibios_fixup_bridge_ranges(resources);
- return 0;
+bridge_ranges_nomem:
- pci_free_resource_list(resources);
- return err;
+}
+/**
- of_create_pci_host_bridge - Create a PCI host bridge structure using
- information passed in the DT.
- @parent: device owning this host bridge
- @ops: pci_ops associated with the host controller
- @host_data: opaque data structure used by the host controller.
- returns a pointer to the newly created pci_host_bridge structure, or
- NULL if the call failed.
- This function will try to obtain the host bridge domain number by
- using of_alias_get_id() call with "pci-domain" as a stem. If that
- fails, a local allocator will be used that will put each host bridge
- in a new domain.
- */
+struct pci_host_bridge * +of_create_pci_host_bridge(struct device *parent, struct pci_ops *ops, void *host_data) +{
- int err, domain, busno;
- struct resource bus_range;
- struct pci_bus *root_bus;
- struct pci_host_bridge *bridge;
- resource_size_t io_base;
- LIST_HEAD(res);
- domain = of_alias_get_id(parent->of_node, "pci-domain");
- if (domain == -ENODEV)
domain = domain_nr++;
- err = of_pci_parse_bus_range(parent->of_node, &bus_range);
- if (err) {
dev_info(parent, "No bus range for %s, using default [0-255]\n",
parent->of_node->full_name);
bus_range.start = 0;
bus_range.end = 255;
bus_range.flags = IORESOURCE_BUS;
- }
- busno = bus_range.start;
- pci_add_resource(&res, &bus_range);
- /* now parse the rest of host bridge bus ranges */
- if (pci_host_bridge_of_get_ranges(parent->of_node, &res, &io_base))
return NULL;
- /* then create the root bus */
- root_bus = pci_create_root_bus_in_domain(parent, domain, busno,
ops, host_data, &res);
- if (!root_bus)
return NULL;
Do we have any code that checks for conflicting domain/bus numbers here? I guess pci_create_root_bus_in_domain() will fail if you have that.
Since pci_create_root_bus_in_domain() is a new function that you just introduced, it would be helpful to change the calling conventions so it returns an error pointer instead of NULL upon failing. of_create_pci_host_bridge() can do the same, but pci_create_root_bus() should keep returning NULL so we don't have to change all the callers.
- bridge = to_pci_host_bridge(root_bus->bridge);
- bridge->io_base = io_base;
- return bridge;
+} +EXPORT_SYMBOL_GPL(of_create_pci_host_bridge); diff --git a/include/linux/pci.h b/include/linux/pci.h index 1eed009..0c5e269 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -395,6 +395,7 @@ struct pci_host_bridge { struct device dev; struct pci_bus *bus; /* root bus */ int domain_nr;
- resource_size_t io_base; /* physical address for the start of I/O area */ struct list_head windows; /* pci_host_bridge_windows */ void (*release_fn)(struct pci_host_bridge *); void *release_data;
What is the io_base used for here?
@@ -1786,11 +1787,23 @@ static inline struct device_node *pci_bus_to_OF_node(struct pci_bus *bus) return bus ? bus->dev.of_node : NULL; } +struct pci_host_bridge * +of_create_pci_host_bridge(struct device *parent, struct pci_ops *ops,
void *host_data);
+void pcibios_fixup_bridge_ranges(struct list_head *resources); #else /* CONFIG_OF */ static inline void pci_set_of_node(struct pci_dev *dev) { } static inline void pci_release_of_node(struct pci_dev *dev) { } static inline void pci_set_bus_of_node(struct pci_bus *bus) { } static inline void pci_release_bus_of_node(struct pci_bus *bus) { }
+static inline struct pci_host_bridge * +pci_host_bridge_of_init(struct device *parent, struct pci_ops *ops,
void *host_data)
+{
- return NULL;
+} #endif /* CONFIG_OF */ #ifdef CONFIG_EEH