[PATCH v4 02/24] fixed generic page.h for non-zero PAGE_OFFSET

From: Mark Salter
Date: Tue Oct 04 2011 - 12:44:20 EST

asm-generic/page.h had several problems when used with a non-zero PAGE_OFFSET.
This patch adds a default ARCH_PFN_OFFSET and fixes the __va, __pa, and
pfn_valid macros to work with non-zero PAGE_OFFSETs.

Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
include/asm-generic/page.h | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/asm-generic/page.h b/include/asm-generic/page.h
index 351889d..37d1fe2 100644
--- a/include/asm-generic/page.h
+++ b/include/asm-generic/page.h
@@ -71,10 +71,14 @@ extern unsigned long memory_end;
#define PAGE_OFFSET (0)

#ifndef __ASSEMBLY__

-#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
-#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
+#define __va(x) ((void *)((unsigned long) (x)))
+#define __pa(x) ((unsigned long) (x))

#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT)
@@ -86,7 +90,7 @@ extern unsigned long memory_end;
#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)

-#define pfn_valid(pfn) ((pfn) < max_mapnr)
+#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr)

#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
((void *)(kaddr) < (void *)memory_end))

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