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-rw-r--r--include/linux/pci.h12
-rw-r--r--include/linux/types.h12
2 files changed, 19 insertions, 5 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8d..956f74b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -577,9 +577,15 @@ int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
int reg, int len, u32 val);
+#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
+typedef u64 pci_bus_addr_t;
+#else
+typedef u32 pci_bus_addr_t;
+#endif
+
struct pci_bus_region {
- dma_addr_t start;
- dma_addr_t end;
+ pci_bus_addr_t start;
+ pci_bus_addr_t end;
};
struct pci_dynids {
@@ -1128,7 +1134,7 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
-static inline dma_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
+static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
{
struct pci_bus_region region;
diff --git a/include/linux/types.h b/include/linux/types.h
index 59698be..8715287 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -139,12 +139,20 @@ typedef unsigned long blkcnt_t;
*/
#define pgoff_t unsigned long
-/* A dma_addr_t can hold any valid DMA or bus address for the platform */
+/*
+ * A dma_addr_t can hold any valid DMA address, i.e., any address returned
+ * by the DMA API.
+ *
+ * If the DMA API only uses 32-bit addresses, dma_addr_t need only be 32
+ * bits wide. Bus addresses, e.g., PCI BARs, may be wider than 32 bits,
+ * but drivers do memory-mapped I/O to ioremapped kernel virtual addresses,
+ * so they don't care about the size of the actual bus addresses.
+ */
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
typedef u64 dma_addr_t;
#else
typedef u32 dma_addr_t;
-#endif /* dma_addr_t */
+#endif
typedef unsigned __bitwise__ gfp_t;
typedef unsigned __bitwise__ fmode_t;
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