PCI: Add pci_bus_addr_t
David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows
to fit in upstream windows") fails to boot on sparc/T5-8:
pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000)
The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA
addresses, i.e., bus addresses returned via the DMA API (dma_map_single(),
etc.), while the PCI core assumed dma_addr_t could hold *any* bus address,
including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so
dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so
they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that
tripped over this mismatch.
Add pci_bus_addr_t, which is wide enough to hold any PCI bus address,
including both raw BAR values and DMA addresses. This will be 64 bits
on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then
dma_addr_t only needs to be wide enough to hold addresses from the DMA API.
[bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at
least as wide as dma_addr_t, documentation]
Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows")
Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB")
Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com
Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231
Reported-by: David Ahern <david.ahern@oracle.com>
Tested-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
CC: stable@vger.kernel.org # v3.19+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_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 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 @@
*/
#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;