android_kernel_xiaomi_sm8350/include/asm-mn10300/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

129 lines
3.6 KiB
C

/* MN10300 Page table definitions
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_PAGE_H
#define _ASM_PAGE_H
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#ifndef __ASSEMBLY__
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE - 1))
#else
#define PAGE_SIZE +(1 << PAGE_SHIFT) /* unary plus marks an
* immediate val not an addr */
#define PAGE_MASK +(~(PAGE_SIZE - 1))
#endif
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#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(addr, vaddr, page) clear_page(addr)
#define copy_user_page(vto, vfrom, vaddr, to) copy_page(vto, vfrom)
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct page *pgtable_t;
#define PTE_MASK PAGE_MASK
#define HPAGE_SHIFT 22
#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
#define pte_val(x) ((x).pte)
#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) })
#include <asm-generic/pgtable-nopmd.h>
#endif /* !__ASSEMBLY__ */
/*
* This handles the memory map.. We could make this a config
* option, but too many people screw it up, and too few need
* it.
*
* A __PAGE_OFFSET of 0xC0000000 means that the kernel has
* a virtual address space of one gigabyte, which limits the
* amount of physical memory you can use to about 950MB.
*/
#ifndef __ASSEMBLY__
/* Pure 2^n version of get_order */
static inline int get_order(unsigned long size) __attribute__((const));
static inline int get_order(unsigned long size)
{
int order;
size = (size - 1) >> (PAGE_SHIFT - 1);
order = -1;
do {
size >>= 1;
order++;
} while (size);
return order;
}
#endif /* __ASSEMBLY__ */
#include <asm/page_offset.h>
#define __PAGE_OFFSET (PAGE_OFFSET_RAW)
#define PAGE_OFFSET ((unsigned long) __PAGE_OFFSET)
/*
* main RAM and kernel working space are coincident at 0x90000000, but to make
* life more interesting, there's also an uncached virtual shadow at 0xb0000000
* - these mappings are fixed in the MMU
*/
#define __pfn_disp (CONFIG_KERNEL_RAM_BASE_ADDRESS >> PAGE_SHIFT)
#define __pa(x) ((unsigned long)(x))
#define __va(x) ((void *)(unsigned long)(x))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define pfn_to_page(pfn) (mem_map + ((pfn) - __pfn_disp))
#define page_to_pfn(page) ((unsigned long)((page) - mem_map) + __pfn_disp)
#define pfn_valid(pfn) \
({ \
unsigned long __pfn = (pfn) - __pfn_disp; \
__pfn < max_mapnr; \
})
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
#define VM_DATA_DEFAULT_FLAGS \
(VM_READ | VM_WRITE | \
((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#endif /* __KERNEL__ */
#endif /* _ASM_PAGE_H */