linux/include/asm-sh/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

182 lines
5.4 KiB
C

#ifndef __ASM_SH_PAGE_H
#define __ASM_SH_PAGE_H
/*
* Copyright (C) 1999 Niibe Yutaka
*/
#include <linux/const.h>
/* PAGE_SHIFT determines the page size */
#if defined(CONFIG_PAGE_SIZE_4KB)
# define PAGE_SHIFT 12
#elif defined(CONFIG_PAGE_SIZE_8KB)
# define PAGE_SHIFT 13
#elif defined(CONFIG_PAGE_SIZE_64KB)
# define PAGE_SHIFT 16
#else
# error "Bogus kernel page size?"
#endif
#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#define PTE_MASK PAGE_MASK
#if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
#define HPAGE_SHIFT 16
#elif defined(CONFIG_HUGETLB_PAGE_SIZE_256K)
#define HPAGE_SHIFT 18
#elif defined(CONFIG_HUGETLB_PAGE_SIZE_1MB)
#define HPAGE_SHIFT 20
#elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
#define HPAGE_SHIFT 22
#elif defined(CONFIG_HUGETLB_PAGE_SIZE_64MB)
#define HPAGE_SHIFT 26
#elif defined(CONFIG_HUGETLB_PAGE_SIZE_512MB)
#define HPAGE_SHIFT 29
#endif
#ifdef CONFIG_HUGETLB_PAGE
#define HPAGE_SIZE (1UL << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE-1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT-PAGE_SHIFT)
#endif
#ifndef __ASSEMBLY__
extern unsigned long shm_align_mask;
extern unsigned long max_low_pfn, min_low_pfn;
extern unsigned long memory_start, memory_end;
extern void clear_page(void *to);
extern void copy_page(void *to, void *from);
#if !defined(CONFIG_CACHE_OFF) && defined(CONFIG_MMU) && \
(defined(CONFIG_CPU_SH5) || defined(CONFIG_CPU_SH4) || \
defined(CONFIG_SH7705_CACHE_32KB))
struct page;
struct vm_area_struct;
extern void clear_user_page(void *to, unsigned long address, struct page *page);
extern void copy_user_page(void *to, void *from, unsigned long address,
struct page *page);
#if defined(CONFIG_CPU_SH4)
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
#endif
#else
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
#endif
/*
* These are used to make use of C type-checking..
*/
#ifdef CONFIG_X2TLB
typedef struct { unsigned long pte_low, pte_high; } pte_t;
typedef struct { unsigned long long pgprot; } pgprot_t;
typedef struct { unsigned long long pgd; } pgd_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; })
#elif defined(CONFIG_SUPERH32)
typedef struct { unsigned long pte_low; } pte_t;
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct { unsigned long pgd; } pgd_t;
#define pte_val(x) ((x).pte_low)
#define __pte(x) ((pte_t) { (x) } )
#else
typedef struct { unsigned long long pte_low; } pte_t;
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct { unsigned long pgd; } pgd_t;
#define pte_val(x) ((x).pte_low)
#define __pte(x) ((pte_t) { (x) } )
#endif
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
typedef struct page *pgtable_t;
#endif /* !__ASSEMBLY__ */
/*
* __MEMORY_START and SIZE are the physical addresses and size of RAM.
*/
#define __MEMORY_START CONFIG_MEMORY_START
#define __MEMORY_SIZE CONFIG_MEMORY_SIZE
/*
* PAGE_OFFSET is the virtual address of the start of kernel address
* space.
*/
#define PAGE_OFFSET CONFIG_PAGE_OFFSET
/*
* Virtual to physical RAM address translation.
*
* In 29 bit mode, the physical offset of RAM from address 0 is visible in
* the kernel virtual address space, and thus we don't have to take
* this into account when translating. However in 32 bit mode this offset
* is not visible (it is part of the PMB mapping) and so needs to be
* added or subtracted as required.
*/
#ifdef CONFIG_32BIT
#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET+__MEMORY_START)
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET-__MEMORY_START))
#else
#define __pa(x) ((unsigned long)(x)-PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
#endif
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
/*
* PFN = physical frame number (ie PFN 0 == physical address 0)
* PFN_START is the PFN of the first page of RAM. By defining this we
* don't have struct page entries for the portion of address space
* between physical address 0 and the start of RAM.
*/
#define PFN_START (__MEMORY_START >> PAGE_SHIFT)
#define ARCH_PFN_OFFSET (PFN_START)
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) >= min_low_pfn && (pfn) < max_low_pfn)
#endif
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
/* vDSO support */
#ifdef CONFIG_VSYSCALL
#define __HAVE_ARCH_GATE_AREA
#endif
/*
* Some drivers need to perform DMA into kmalloc'ed buffers
* and so we have to increase the kmalloc minalign for this.
*/
#define ARCH_KMALLOC_MINALIGN L1_CACHE_BYTES
#ifdef CONFIG_SUPERH64
/*
* While BYTES_PER_WORD == 4 on the current sh64 ABI, GCC will still
* happily generate {ld/st}.q pairs, requiring us to have 8-byte
* alignment to avoid traps. The kmalloc alignment is gauranteed by
* virtue of L1_CACHE_BYTES, requiring this to only be special cased
* for slab caches.
*/
#define ARCH_SLAB_MINALIGN 8
#endif
#endif /* __ASM_SH_PAGE_H */