[RFC 1/3] ARM: Allow unmapping of fixed PCI I/O mappings

[Thierry Reding <thierry.reding@gmail.com>]

The new pci_iounmap_io() function can be used to unmap a fixed PCI I/O
mapping as established by pci_ioremap_io(). This will be useful to
support unbinding of PCI host drivers.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 arch/arm/include/asm/io.h | 1 +
 arch/arm/mm/ioremap.c     | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index d070741..80c3826 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -172,6 +172,7 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
 #define PCI_IO_VIRT_BASE	0xfee00000
 
 extern int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr);
+extern void pci_iounmap_io(unsigned int offset);
 
 /*
  * Now, pick up the machine-defined IO definitions
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index f123d6e..c7504c9 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -448,4 +448,10 @@ int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
 				  __pgprot(get_mem_type(MT_DEVICE)->prot_pte));
 }
 EXPORT_SYMBOL_GPL(pci_ioremap_io);
+
+void pci_iounmap_io(unsigned int offset)
+{
+	unmap_kernel_range(PCI_IO_VIRT_BASE + offset, SZ_64K);
+}
+EXPORT_SYMBOL_GPL(pci_iounmap_io);
 #endif
-- 
1.8.3.4