Commit 06d5e032 authored by Sonic Zhang's avatar Sonic Zhang Committed by Linus Torvalds

include/asm-generic/page.h: calculate virt_to_page and page_to_virt via predefined macro

On NOMMU architectures, if physical memory doesn't start from 0,
ARCH_PFN_OFFSET is defined to generate page index in mem_map array.
Because virtual address is equal to physical address, PAGE_OFFSET is
always 0.  virt_to_page and page_to_virt should not index page by
PAGE_OFFSET directly.
Signed-off-by: default avatarSonic Zhang <>
Cc: Greg Ungerer <>
Cc: Geert Uytterhoeven <>
Cc: David Howells <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 37a1c49a
......@@ -79,8 +79,8 @@ extern unsigned long memory_end;
#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
#define virt_to_page(addr) (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT))
#define page_to_virt(page) ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET)
#define virt_to_page(addr) pfn_to_page(virt_to_pfn(addr))
#define page_to_virt(page) pfn_to_virt(page_to_pfn(page))
#ifndef page_to_phys
#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)
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