PCI: Add pci_remap_iospace() to map bus I/O resources

Add pci_remap_iospace() to map bus I/O resources into the CPU virtual
address space.  Architectures with special needs may provide their own
version, but most should be able to use this one.

This function is useful for PCI host bridge drivers that need to map the
PCI I/O resources into virtual memory space.

[bhelgaas: phys_addr description, drop temporary "err" variable]
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
CC: Arnd Bergmann <arnd@arndb.de>

2 files changed, 7 insertions, 0 deletions

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 53b2acc38213..977e545a64c3 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -249,6 +249,10 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 #define pgprot_writecombine pgprot_noncached
 #endif
 
+#ifndef pgprot_device
+#define pgprot_device pgprot_noncached
+#endif
+
 /*
  * When walking page tables, get the address of the next boundary,
  * or the end address of the range if that comes earlier.  Although no
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 150da2d644e7..b4995fdfffb1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1100,6 +1100,9 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
                                                   resource_size_t),
                         void *alignf_data);
 
+
+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)
 {
         struct pci_bus_region region;