kernel-ark/include/asm-frv/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

79 lines
2.2 KiB
C

#ifndef _ASM_PAGE_H
#define _ASM_PAGE_H
#include <asm/virtconvert.h>
#include <asm/mem-layout.h>
#include <asm/sections.h>
#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(pgaddr) memset((pgaddr), 0, PAGE_SIZE)
#define copy_page(to,from) memcpy((to), (from), PAGE_SIZE)
#define clear_user_page(pgaddr, vaddr, page) memset((pgaddr), 0, PAGE_SIZE)
#define copy_user_page(vto, vfrom, vaddr, topg) memcpy((vto), (vfrom), PAGE_SIZE)
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long ste[64];} pmd_t;
typedef struct { pmd_t pue[1]; } pud_t;
typedef struct { pud_t pge[1]; } 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).ste[0])
#define pud_val(x) ((x).pue[0])
#define pgd_val(x) ((x).pge[0])
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pud(x) ((pud_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#define PTE_MASK PAGE_MASK
#define devmem_is_allowed(pfn) 1
#define __pa(vaddr) virt_to_phys((void *) (unsigned long) (vaddr))
#define __va(paddr) phys_to_virt((unsigned long) (paddr))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
extern unsigned long max_low_pfn;
extern unsigned long min_low_pfn;
extern unsigned long max_pfn;
#ifdef CONFIG_MMU
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#else
#define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT)
#define pfn_valid(pfn) ((pfn) >= min_low_pfn && (pfn) < max_low_pfn)
#endif
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#ifdef CONFIG_MMU
#define VM_DATA_DEFAULT_FLAGS \
(VM_READ | VM_WRITE | \
((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#endif
#endif /* __ASSEMBLY__ */
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
#endif /* _ASM_PAGE_H */