Several platforms use a rather generic version of parsing
the device tree to find the host bridge ranges. Move that
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@xxxxxxx>
Cc: Catalin Marinas <Catalin.Marinas@xxxxxxx>
Cc: Will Deacon <Will.Deacon@xxxxxxx>
---
drivers/pci/host-bridge.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/pci/probe.c | 11 ++++++
include/linux/pci.h | 14 ++++++++
3 files changed, 117 insertions(+)
diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 06ace62..9d11deb 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -6,6 +6,7 @@
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
+#include <linux/of_address.h>
#include "pci.h"
@@ -91,3 +92,94 @@ 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
+ *
+ * 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 will then apply their filtering based on the limitations
+ * of each platform. One general restriction seems to be the number of IO space
+ * ranges, the PCI framework makes intensive use of struct resource management,
+ * and for IORESOURCE_IO types they can only be requested if they are contained
+ * within the global ioport_resource, so that should be limited to one IO space
+ * range.
+ */
+static int pci_host_bridge_of_get_ranges(struct device_node *dev,
+ struct list_head *resources)
+{
+ 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
+ * (some FW try to feed us with non sensical zero sized regions
+ * such as power3 which look like some kind of attempt
+ * at exposing the VGA memory hole) 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);
+
+ pci_add_resource_offset(resources, res,
+ range.cpu_addr - range.pci_addr);
+ }
+
+ /* Apply architecture specific fixups for the ranges */
+ pcibios_fixup_bridge_ranges(resources);
+
+ return 0;
+
+bridge_ranges_nomem:
+ pci_free_resource_list(resources);
+ return err;
+}
+
+struct pci_host_bridge *
+pci_host_bridge_of_init(struct device *parent, int busno, struct pci_ops *ops,
+ void *host_data, struct list_head *resources)
+{
+ struct pci_bus *root_bus;
+ struct pci_host_bridge *bridge;
+
+ /* first parse the host bridge bus ranges */
+ if (pci_host_bridge_of_get_ranges(parent->of_node, resources))
+ return NULL;
+
+ /* then create the root bus */
+ root_bus = pci_create_root_bus(parent, busno, ops, host_data, resources);
+ if (!root_bus)
+ return NULL;
+
+ bridge = to_pci_host_bridge(root_bus->bridge);
+
+ return bridge;
+}
+EXPORT_SYMBOL(pci_host_bridge_of_init);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 6e34498..16febae 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1787,6 +1787,17 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
list_for_each_entry_safe(window, n, resources, list) {
list_move_tail(&window->list, &bridge->windows);
res = window->res;
+ /*
+ * IO resources are stored in the kernel with a CPU start
+ * address of zero. Adjust the data accordingly and remember
+ * the offset
+ */
+ if (resource_type(res) == IORESOURCE_IO) {
+ bridge->io_offset = res->start;
+ res->end -= res->start;
+ window->offset -= res->start;
+ res->start = 0;
+ }
offset = window->offset;
if (res->flags & IORESOURCE_BUS)
pci_bus_insert_busn_res(b, bus, res->end);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index fb57c89..8953997 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -394,6 +394,8 @@ struct pci_host_bridge_window {
struct pci_host_bridge {
struct device dev;
struct pci_bus *bus; /* root bus */
+ resource_size_t io_offset; /* CPU address offset for io resources */
+ int domain_nr;
struct list_head windows; /* pci_host_bridge_windows */
void (*release_fn)(struct pci_host_bridge *);
void *release_data;
@@ -1762,11 +1764,23 @@ 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 *
+pci_host_bridge_of_init(struct device *parent, int busno, struct pci_ops *ops,
+ void *host_data, struct list_head *resources);
+
+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, struct list_head *resources)
+{
+ return NULL;
+}
#endif /* CONFIG_OF */
#ifdef CONFIG_EEH
--
1.8.5.3
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