linux/arch/arm/include/asm/page.h

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/*
* arch/arm/include/asm/page.h
*
* Copyright (C) 1995-2003 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _ASMARM_PAGE_H
#define _ASMARM_PAGE_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__
#ifndef CONFIG_MMU
#include "page-nommu.h"
#else
#include <asm/glue.h>
/*
* User Space Model
* ================
*
* This section selects the correct set of functions for dealing with
* page-based copying and clearing for user space for the particular
* processor(s) we're building for.
*
* We have the following to choose from:
* v4wt - ARMv4 with writethrough cache, without minicache
* v4wb - ARMv4 with writeback cache, without minicache
* v4_mc - ARMv4 with minicache
* xscale - Xscale
* xsc3 - XScalev3
*/
#undef _USER
#undef MULTI_USER
#ifdef CONFIG_CPU_COPY_V4WT
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4wt
# endif
#endif
#ifdef CONFIG_CPU_COPY_V4WB
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4wb
# endif
#endif
#ifdef CONFIG_CPU_COPY_FEROCEON
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER feroceon
# endif
#endif
#ifdef CONFIG_CPU_COPY_FA
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER fa
# endif
#endif
#ifdef CONFIG_CPU_SA1100
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER v4_mc
# endif
#endif
#ifdef CONFIG_CPU_XSCALE
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER xscale_mc
# endif
#endif
#ifdef CONFIG_CPU_XSC3
# ifdef _USER
# define MULTI_USER 1
# else
# define _USER xsc3_mc
# endif
#endif
#ifdef CONFIG_CPU_COPY_V6
# define MULTI_USER 1
#endif
#if !defined(_USER) && !defined(MULTI_USER)
#error Unknown user operations model
#endif
struct page;
struct vm_area_struct;
struct cpu_user_fns {
void (*cpu_clear_user_highpage)(struct page *page, unsigned long vaddr);
void (*cpu_copy_user_highpage)(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma);
};
#ifdef MULTI_USER
extern struct cpu_user_fns cpu_user;
#define __cpu_clear_user_highpage cpu_user.cpu_clear_user_highpage
#define __cpu_copy_user_highpage cpu_user.cpu_copy_user_highpage
#else
#define __cpu_clear_user_highpage __glue(_USER,_clear_user_highpage)
#define __cpu_copy_user_highpage __glue(_USER,_copy_user_highpage)
extern void __cpu_clear_user_highpage(struct page *page, unsigned long vaddr);
extern void __cpu_copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma);
#endif
#define clear_user_highpage(page,vaddr) \
__cpu_clear_user_highpage(page, vaddr)
#define __HAVE_ARCH_COPY_USER_HIGHPAGE
#define copy_user_highpage(to,from,vaddr,vma) \
__cpu_copy_user_highpage(to, from, vaddr, vma)
#define clear_page(page) memset((void *)(page), 0, PAGE_SIZE)
extern void copy_page(void *to, const void *from);
#define __HAVE_ARCH_GATE_AREA 1
#ifdef CONFIG_ARM_LPAE
#include <asm/pgtable-3level-types.h>
#else
#include <asm/pgtable-2level-types.h>
#endif
#endif /* CONFIG_MMU */
typedef struct page *pgtable_t;
ARM: 6913/1: sparsemem: allow pfn_valid to be overridden when using SPARSEMEM In commit eb33575c ("[ARM] Double check memmap is actually valid with a memmap has unexpected holes V2"), a new function, memmap_valid_within, was introduced to mmzone.h so that holes in the memmap which pass pfn_valid in SPARSEMEM configurations can be detected and avoided. The fix to this problem checks that the pfn <-> page linkages are correct by calculating the page for the pfn and then checking that page_to_pfn on that page returns the original pfn. Unfortunately, in SPARSEMEM configurations, this results in reading from the page flags to determine the correct section. Since the memmap here has been freed, junk is read from memory and the check is no longer robust. In the best case, reading from /proc/pagetypeinfo will give you the wrong answer. In the worst case, you get SEGVs, Kernel OOPses and hung CPUs. Furthermore, ioremap implementations that use pfn_valid to disallow the remapping of normal memory will break. This patch allows architectures to provide their own pfn_valid function instead of using the default implementation used by sparsemem. The architecture-specific version is aware of the memmap state and will return false when passed a pfn for a freed page within a valid section. Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-19 20:21:14 +08:00
#ifdef CONFIG_HAVE_ARCH_PFN_VALID
extern int pfn_valid(unsigned long);
#endif
#include <asm/memory.h>
#endif /* !__ASSEMBLY__ */
#define VM_DATA_DEFAULT_FLAGS \
(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#include <asm-generic/getorder.h>
#endif