PCI: OF: Add generic function to parse and allocate PCI resources

The patch moves the gen_pci_parse_request_of_pci_ranges() function from
drivers/pci/host/pci-host-common.c into drivers/pci/of.c to easily share
common source code between PCI host drivers.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

3 files changed, 62 insertions, 47 deletions

diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
index 44a47d4f0b8f..efd904d93562 100644
--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -24,50 +24,6 @@
 #include <linux/pci-ecam.h>
 #include <linux/platform_device.h>
 
-static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
-                       struct list_head *resources, struct resource **bus_range)
-{
-        int err, res_valid = 0;
-        struct device_node *np = dev->of_node;
-        resource_size_t iobase;
-        struct resource_entry *win, *tmp;
-
-        err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
-        if (err)
-                return err;
-
-        err = devm_request_pci_bus_resources(dev, resources);
-        if (err)
-                return err;
-
-        resource_list_for_each_entry_safe(win, tmp, resources) {
-                struct resource *res = win->res;
-
-                switch (resource_type(res)) {
-                case IORESOURCE_IO:
-                        err = pci_remap_iospace(res, iobase);
-                        if (err) {
-                                dev_warn(dev, "error %d: failed to map resource %pR\n",
-                                         err, res);
-                                resource_list_destroy_entry(win);
-                        }
-                        break;
-                case IORESOURCE_MEM:
-                        res_valid |= !(res->flags & IORESOURCE_PREFETCH);
-                        break;
-                case IORESOURCE_BUS:
-                        *bus_range = res;
-                        break;
-                }
-        }
-
-        if (res_valid)
-                return 0;
-
-        dev_err(dev, "non-prefetchable memory resource required\n");
-        return -EINVAL;
-}
-
 static void gen_pci_unmap_cfg(void *ptr)
 {
         pci_ecam_free((struct pci_config_window *)ptr);
@@ -82,9 +38,9 @@ static struct pci_config_window *gen_pci_init(struct device *dev,
         struct pci_config_window *cfg;
 
         /* Parse our PCI ranges and request their resources */
-        err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
+        err = pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
         if (err)
-                goto err_out;
+                return ERR_PTR(err);
 
         err = of_address_to_resource(dev->of_node, 0, &cfgres);
         if (err) {
@@ -135,7 +91,6 @@ int pci_host_common_probe(struct platform_device *pdev,
         of_pci_check_probe_only();
 
         /* Parse and map our Configuration Space windows */
-        INIT_LIST_HEAD(&resources);
         cfg = gen_pci_init(dev, &resources, ops);
         if (IS_ERR(cfg))
                 return PTR_ERR(cfg);
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index e112da11630e..54e210501b73 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -88,3 +88,54 @@ struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
         return NULL;
 #endif
 }
+
+int pci_parse_request_of_pci_ranges(struct device *dev,
+                                    struct list_head *resources,
+                                    struct resource **bus_range)
+{
+        int err, res_valid = 0;
+        struct device_node *np = dev->of_node;
+        resource_size_t iobase;
+        struct resource_entry *win, *tmp;
+
+        INIT_LIST_HEAD(resources);
+        err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
+        if (err)
+                return err;
+
+        err = devm_request_pci_bus_resources(dev, resources);
+        if (err)
+                goto out_release_res;
+
+        resource_list_for_each_entry_safe(win, tmp, resources) {
+                struct resource *res = win->res;
+
+                switch (resource_type(res)) {
+                case IORESOURCE_IO:
+                        err = pci_remap_iospace(res, iobase);
+                        if (err) {
+                                dev_warn(dev, "error %d: failed to map resource %pR\n",
+                                         err, res);
+                                resource_list_destroy_entry(win);
+                        }
+                        break;
+                case IORESOURCE_MEM:
+                        res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+                        break;
+                case IORESOURCE_BUS:
+                        if (bus_range)
+                                *bus_range = res;
+                        break;
+                }
+        }
+
+        if (res_valid)
+                return 0;
+
+        dev_err(dev, "non-prefetchable memory resource required\n");
+        err = -EINVAL;
+
+ out_release_res:
+        pci_free_resource_list(resources);
+        return err;
+}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c170c9250c8b..c7a701abbf17 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2182,6 +2182,9 @@ void pci_release_of_node(struct pci_dev *dev);
 void pci_set_bus_of_node(struct pci_bus *bus);
 void pci_release_bus_of_node(struct pci_bus *bus);
 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus);
+int pci_parse_request_of_pci_ranges(struct device *dev,
+                                    struct list_head *resources,
+                                    struct resource **bus_range);
 
 /* Arch may override this (weak) */
 struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus);
@@ -2206,6 +2209,12 @@ static inline struct device_node *
 pci_device_to_OF_node(const struct pci_dev *pdev) { return NULL; }
 static inline struct irq_domain *
 pci_host_bridge_of_msi_domain(struct pci_bus *bus) { return NULL; }
+static inline int pci_parse_request_of_pci_ranges(struct device *dev,
+                                                  struct list_head *resources,
+                                                  struct resource **bus_range)
+{
+        return -EINVAL;
+}
 #endif  /* CONFIG_OF */
 
 #ifdef CONFIG_ACPI