linux/include/asm-mips/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

192 lines
5.0 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 1999, 2000, 03 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_PAGE_H
#define _ASM_PAGE_H
#include <spaces.h>
/*
* PAGE_SHIFT determines the page size
*/
#ifdef CONFIG_PAGE_SIZE_4KB
#define PAGE_SHIFT 12
#endif
#ifdef CONFIG_PAGE_SIZE_8KB
#define PAGE_SHIFT 13
#endif
#ifdef CONFIG_PAGE_SIZE_16KB
#define PAGE_SHIFT 14
#endif
#ifdef CONFIG_PAGE_SIZE_64KB
#define PAGE_SHIFT 16
#endif
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
#ifndef __ASSEMBLY__
#include <linux/pfn.h>
#include <asm/io.h>
extern void build_clear_page(void);
extern void build_copy_page(void);
/*
* It's normally defined only for FLATMEM config but it's
* used in our early mem init code for all memory models.
* So always define it.
*/
#define ARCH_PFN_OFFSET PFN_UP(PHYS_OFFSET)
extern void clear_page(void * page);
extern void copy_page(void * to, void * from);
extern unsigned long shm_align_mask;
static inline unsigned long pages_do_alias(unsigned long addr1,
unsigned long addr2)
{
return (addr1 ^ addr2) & shm_align_mask;
}
struct page;
static inline void clear_user_page(void *addr, unsigned long vaddr,
struct page *page)
{
extern void (*flush_data_cache_page)(unsigned long addr);
clear_page(addr);
if (pages_do_alias((unsigned long) addr, vaddr & PAGE_MASK))
flush_data_cache_page((unsigned long)addr);
}
extern void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
struct page *to);
struct vm_area_struct;
extern void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma);
#define __HAVE_ARCH_COPY_USER_HIGHPAGE
/*
* These are used to make use of C type-checking..
*/
#ifdef CONFIG_64BIT_PHYS_ADDR
#ifdef CONFIG_CPU_MIPS32
typedef struct { unsigned long pte_low, pte_high; } pte_t;
#define pte_val(x) ((x).pte_low | ((unsigned long long)(x).pte_high << 32))
#define __pte(x) ({ pte_t __pte = {(x), ((unsigned long long)(x)) >> 32}; __pte; })
#else
typedef struct { unsigned long long pte; } pte_t;
#define pte_val(x) ((x).pte)
#define __pte(x) ((pte_t) { (x) } )
#endif
#else
typedef struct { unsigned long pte; } pte_t;
#define pte_val(x) ((x).pte)
#define __pte(x) ((pte_t) { (x) } )
#endif
typedef struct page *pgtable_t;
/*
* For 3-level pagetables we defines these ourselves, for 2-level the
* definitions are supplied by <asm-generic/pgtable-nopmd.h>.
*/
#ifdef CONFIG_64BIT
typedef struct { unsigned long pmd; } pmd_t;
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) } )
#endif
/*
* Right now we don't support 4-level pagetables, so all pud-related
* definitions come from <asm-generic/pgtable-nopud.h>.
*/
/*
* Finall the top of the hierarchy, the pgd
*/
typedef struct { unsigned long pgd; } pgd_t;
#define pgd_val(x) ((x).pgd)
#define __pgd(x) ((pgd_t) { (x) } )
/*
* Manipulate page protection bits
*/
typedef struct { unsigned long pgprot; } pgprot_t;
#define pgprot_val(x) ((x).pgprot)
#define __pgprot(x) ((pgprot_t) { (x) } )
/*
* On R4000-style MMUs where a TLB entry is mapping a adjacent even / odd
* pair of pages we only have a single global bit per pair of pages. When
* writing to the TLB make sure we always have the bit set for both pages
* or none. This macro is used to access the `buddy' of the pte we're just
* working on.
*/
#define ptep_buddy(x) ((pte_t *)((unsigned long)(x) ^ sizeof(pte_t)))
#endif /* !__ASSEMBLY__ */
/*
* __pa()/__va() should be used only during mem init.
*/
#ifdef CONFIG_64BIT
#define __pa(x) \
({ \
unsigned long __x = (unsigned long)(x); \
__x < CKSEG0 ? XPHYSADDR(__x) : CPHYSADDR(__x); \
})
#else
#define __pa(x) \
((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
#endif
#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
#elif defined(CONFIG_SPARSEMEM)
/* pfn_valid is defined in linux/mmzone.h */
#elif defined(CONFIG_NEED_MULTIPLE_NODES)
#define pfn_valid(pfn) \
({ \
unsigned long __pfn = (pfn); \
int __n = pfn_to_nid(__pfn); \
((__n >= 0) ? (__pfn < NODE_DATA(__n)->node_start_pfn + \
NODE_DATA(__n)->node_spanned_pages) \
: 0); \
})
#endif
#define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(virt_to_phys(kaddr)))
#define virt_addr_valid(kaddr) pfn_valid(PFN_DOWN(virt_to_phys(kaddr)))
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#define UNCAC_ADDR(addr) ((addr) - PAGE_OFFSET + UNCAC_BASE)
#define CAC_ADDR(addr) ((addr) - UNCAC_BASE + PAGE_OFFSET)
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
#endif /* _ASM_PAGE_H */