kernel-fxtec-pro1x/include/asm-um/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

125 lines
3.5 KiB
C

/*
* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
* Copyright 2003 PathScale, Inc.
* Licensed under the GPL
*/
#ifndef __UM_PAGE_H
#define __UM_PAGE_H
#include <linux/const.h>
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#ifndef __ASSEMBLY__
struct page;
#include <linux/types.h>
#include <asm/vm-flags.h>
/*
* These are used to make use of C type-checking..
*/
#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
#define copy_page(to,from) memcpy((void *)(to), (void *)(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)
#if defined(CONFIG_3_LEVEL_PGTABLES) && !defined(CONFIG_64BIT)
typedef struct { unsigned long pte_low, pte_high; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pgd; } pgd_t;
#define pte_val(x) ((x).pte_low | ((unsigned long long) (x).pte_high << 32))
#define pte_get_bits(pte, bits) ((pte).pte_low & (bits))
#define pte_set_bits(pte, bits) ((pte).pte_low |= (bits))
#define pte_clear_bits(pte, bits) ((pte).pte_low &= ~(bits))
#define pte_copy(to, from) ({ (to).pte_high = (from).pte_high; \
smp_wmb(); \
(to).pte_low = (from).pte_low; })
#define pte_is_zero(pte) (!((pte).pte_low & ~_PAGE_NEWPAGE) && !(pte).pte_high)
#define pte_set_val(pte, phys, prot) \
({ (pte).pte_high = (phys) >> 32; \
(pte).pte_low = (phys) | pgprot_val(prot); })
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) } )
typedef unsigned long long pfn_t;
typedef unsigned long long phys_t;
#else
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pgd; } pgd_t;
#ifdef CONFIG_3_LEVEL_PGTABLES
typedef struct { unsigned long pmd; } pmd_t;
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) } )
#endif
#define pte_val(x) ((x).pte)
#define pte_get_bits(p, bits) ((p).pte & (bits))
#define pte_set_bits(p, bits) ((p).pte |= (bits))
#define pte_clear_bits(p, bits) ((p).pte &= ~(bits))
#define pte_copy(to, from) ((to).pte = (from).pte)
#define pte_is_zero(p) (!((p).pte & ~_PAGE_NEWPAGE))
#define pte_set_val(p, phys, prot) (p).pte = (phys | pgprot_val(prot))
typedef unsigned long pfn_t;
typedef unsigned long phys_t;
#endif
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct page *pgtable_t;
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
extern unsigned long uml_physmem;
#define PAGE_OFFSET (uml_physmem)
#define KERNELBASE PAGE_OFFSET
#define __va_space (8*1024*1024)
#include "mem.h"
/* Cast to unsigned long before casting to void * to avoid a warning from
* mmap_kmem about cutting a long long down to a void *. Not sure that
* casting is the right thing, but 32-bit UML can't have 64-bit virtual
* addresses
*/
#define __pa(virt) to_phys((void *) (unsigned long) (virt))
#define __va(phys) to_virt((unsigned long) (phys))
#define phys_to_pfn(p) ((pfn_t) ((p) >> PAGE_SHIFT))
#define pfn_to_phys(pfn) ((phys_t) ((pfn) << PAGE_SHIFT))
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#define virt_addr_valid(v) pfn_valid(phys_to_pfn(__pa(v)))
extern struct page *arch_validate(struct page *page, gfp_t mask, int order);
#define HAVE_ARCH_VALIDATE
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
#endif /* __ASSEMBLY__ */
#endif /* __UM_PAGE_H */