From 4d7d6936eb29af7cca330937808312aa5f61454d Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Thu, 13 Dec 2007 12:56:33 +0100 Subject: Introduce map_physmem() and unmap_physmem() map_physmem() returns a virtual address which can be used to access a given physical address without involving the cache. unmap_physmem() should be called when the virtual address returned by map_physmem() is no longer needed. This patch adds a stub implementation which simply returns the physical address cast to a uchar * for all architectures except AVR32, which converts the physical address to an uncached virtual mapping. unmap_physmem() is a no-op on all architectures, but if any architecture needs to do such mappings through the TLB, this is the hook where those TLB entries can be invalidated. Signed-off-by: Haavard Skinnemoen --- include/asm-i386/io.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'include/asm-i386/io.h') diff --git a/include/asm-i386/io.h b/include/asm-i386/io.h index e64d788..db4f442 100644 --- a/include/asm-i386/io.h +++ b/include/asm-i386/io.h @@ -205,4 +205,30 @@ static inline void sync(void) { } +/* + * Given a physical address and a length, return a virtual address + * that can be used to access the memory range with the caching + * properties specified by "flags". + */ +typedef unsigned long phys_addr_t; + +#define MAP_NOCACHE (0) +#define MAP_WRCOMBINE (0) +#define MAP_WRBACK (0) +#define MAP_WRTHROUGH (0) + +static inline void * +map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags) +{ + return (void *)paddr; +} + +/* + * Take down a mapping set up by map_physmem(). + */ +static inline void unmap_physmem(void *vaddr, unsigned long flags) +{ + +} + #endif -- cgit v1.1