linux/include/asm-m68knommu/page.h
Andrea Righi 27ac792ca0 PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit
boundary. For example:

	u64 val = PAGE_ALIGN(size);

always returns a value < 4GB even if size is greater than 4GB.

The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for
example):

#define PAGE_SHIFT      12
#define PAGE_SIZE       (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK       (~(PAGE_SIZE-1))
...
#define PAGE_ALIGN(addr)       (((addr)+PAGE_SIZE-1)&PAGE_MASK)

The "~" is performed on a 32-bit value, so everything in "and" with
PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary.
Using the ALIGN() macro seems to be the right way, because it uses
typeof(addr) for the mask.

Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in
include/linux/mm.h.

See also lkml discussion: http://lkml.org/lkml/2008/6/11/237

[akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c]
[akpm@linux-foundation.org: fix v850]
[akpm@linux-foundation.org: fix powerpc]
[akpm@linux-foundation.org: fix arm]
[akpm@linux-foundation.org: fix mips]
[akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c]
[akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c]
[akpm@linux-foundation.org: fix powerpc]
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00

78 lines
2.2 KiB
C

#ifndef _M68KNOMMU_PAGE_H
#define _M68KNOMMU_PAGE_H
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT (12)
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#include <asm/setup.h>
#ifndef __ASSEMBLY__
#define get_user_page(vaddr) __get_free_page(GFP_KERNEL)
#define free_user_page(page, addr) free_page(addr)
#define clear_page(page) memset((page), 0, PAGE_SIZE)
#define copy_page(to,from) memcpy((to), (from), PAGE_SIZE)
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \
alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr)
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd[16]; } pmd_t;
typedef struct { unsigned long pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct page *pgtable_t;
#define pte_val(x) ((x).pte)
#define pmd_val(x) ((&x)->pmd[0])
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
extern unsigned long memory_start;
extern unsigned long memory_end;
#endif /* !__ASSEMBLY__ */
#include <asm/page_offset.h>
#define PAGE_OFFSET (PAGE_OFFSET_RAW)
#ifndef __ASSEMBLY__
#define __pa(vaddr) virt_to_phys((void *)(vaddr))
#define __va(paddr) phys_to_virt((unsigned long)(paddr))
#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 pfn_to_page(pfn) virt_to_page(pfn_to_virt(pfn))
#define page_to_pfn(page) virt_to_pfn(page_to_virt(page))
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
((void *)(kaddr) < (void *)memory_end))
#endif /* __ASSEMBLY__ */
#include <asm-generic/page.h>
#endif /* _M68KNOMMU_PAGE_H */