1 files changed, 29 insertions, 6 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2ff9d26a078f..e19a69613d8f 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -364,9 +364,26 @@ static inline void pci_add_saved_cap(struct pci_dev *pci_dev,
         hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space);
 }
 
-#ifndef PCI_BUS_NUM_RESOURCES
-#define PCI_BUS_NUM_RESOURCES   16
-#endif
+/*
+ * The first PCI_BRIDGE_RESOURCE_NUM PCI bus resources (those that correspond
+ * to P2P or CardBus bridge windows) go in a table.  Additional ones (for
+ * buses below host bridges or subtractive decode bridges) go in the list.
+ * Use pci_bus_for_each_resource() to iterate through all the resources.
+ */
+
+/*
+ * PCI_SUBTRACTIVE_DECODE means the bridge forwards the window implicitly
+ * and there's no way to program the bridge with the details of the window.
+ * This does not apply to ACPI _CRS windows, even with the _DEC subtractive-
+ * decode bit set, because they are explicit and can be programmed with _SRS.
+ */
+#define PCI_SUBTRACTIVE_DECODE  0x1
+
+struct pci_bus_resource {
+        struct list_head list;
+        struct resource *res;
+        unsigned int flags;
+};
 
 #define PCI_REGION_FLAG_MASK    0x0fU   /* These bits of resource flags tell us the PCI region flags */
 
@@ -377,8 +394,8 @@ struct pci_bus {
         struct list_head devices;       /* list of devices on this bus */
         struct pci_dev  *self;          /* bridge device as seen by parent */
         struct list_head slots;         /* list of slots on this bus */
-        struct resource *resource[PCI_BUS_NUM_RESOURCES];
-                                        /* address space routed to this bus */
+        struct resource *resource[PCI_BRIDGE_RESOURCE_NUM];
+        struct list_head resources;     /* address space routed to this bus */
 
         struct pci_ops  *ops;           /* configuration access functions */
         void            *sysdata;       /* hook for sys-specific extension */
@@ -829,8 +846,14 @@ int pci_request_selected_regions_exclusive(struct pci_dev *, int, const char *);
 void pci_release_selected_regions(struct pci_dev *, int);
 
 /* drivers/pci/bus.c */
+void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, unsigned int flags);
+struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n);
+void pci_bus_remove_resources(struct pci_bus *bus);
+
 #define pci_bus_for_each_resource(bus, res, i)                          \
-        for (i = 0; res = bus->resource[i], i < PCI_BUS_NUM_RESOURCES; i++)
+        for (i = 0;                                                     \
+            (res = pci_bus_resource_n(bus, i)) || i < PCI_BRIDGE_RESOURCE_NUM; \
+             i++)
 
 int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
                         struct resource *res, resource_size_t size,