ARM: Add fixed PCI i/o mapping

This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.

This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 4f55f5062ab7..8727802f8661 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -36,6 +36,7 @@
 #include <asm/system_info.h>
 
 #include <asm/mach/map.h>
+#include <asm/mach/pci.h>
 #include "mm.h"
 
 int ioremap_page(unsigned long virt, unsigned long phys,
@@ -383,3 +384,16 @@ void __arm_iounmap(volatile void __iomem *io_addr)
         arch_iounmap(io_addr);
 }
 EXPORT_SYMBOL(__arm_iounmap);
+
+#ifdef CONFIG_PCI
+int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
+{
+        BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT);
+
+        return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
+                                  PCI_IO_VIRT_BASE + offset + SZ_64K,
+                                  phys_addr,
+                                  __pgprot(get_mem_type(MT_DEVICE)->prot_pte));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_io);
+#endif