LXR linux/include/asm-powerpc/page.h

   1#ifndef _ASM_POWERPC_PAGE_H
   2#define _ASM_POWERPC_PAGE_H
   3
   4/*
   5 * Copyright (C) 2001,2005 IBM Corporation.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the License, or (at your option) any later version.
  11 */
  12
  13#include <asm/asm-compat.h>
  14#include <asm/kdump.h>
  15
  16/*
  17 * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
  18 * page size. When using 64K pages however, whether we are really supporting
  19 * 64K pages in HW or not is irrelevant to those definitions.
  20 */
  21#ifdef CONFIG_PPC_64K_PAGES
  22#define PAGE_SHIFT              16
  23#else
  24#define PAGE_SHIFT              12
  25#endif
  26
  27#define PAGE_SIZE               (ASM_CONST(1) << PAGE_SHIFT)
  28
  29/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
  30#define __HAVE_ARCH_GATE_AREA           1
  31
  32/*
  33 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  34 * assign PAGE_MASK to a larger type it gets extended the way we want
  35 * (i.e. with 1s in the high bits)
  36 */
  37#define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
  38
  39/*
  40 * KERNELBASE is the virtual address of the start of the kernel, it's often
  41 * the same as PAGE_OFFSET, but _might not be_.
  42 *
  43 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  44 *
  45 * To get a physical address from a virtual one you subtract PAGE_OFFSET,
  46 * _not_ KERNELBASE.
  47 *
  48 * If you want to know something's offset from the start of the kernel you
  49 * should subtract KERNELBASE.
  50 *
  51 * If you want to test if something's a kernel address, use is_kernel_addr().
  52 */
  53
  54#define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
  55#define KERNELBASE      (PAGE_OFFSET + PHYSICAL_START)
  56
  57#ifdef CONFIG_FLATMEM
  58#define pfn_valid(pfn)          ((pfn) < max_mapnr)
  59#endif
  60
  61#define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  62#define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
  63#define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  64
  65#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
  66#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
  67
  68/*
  69 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
  70 * and needs to be executable.  This means the whole heap ends
  71 * up being executable.
  72 */
  73#define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
  74                                 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  75
  76#define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
  77                                 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  78
  79#ifdef __powerpc64__
  80#include <asm/page_64.h>
  81#else
  82#include <asm/page_32.h>
  83#endif
  84
  85/* align addr on a size boundary - adjust address up/down if needed */
  86#define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
  87#define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
  88
  89/* align addr on a size boundary - adjust address up if needed */
  90#define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
  91
  92/* to align the pointer to the (next) page boundary */
  93#define PAGE_ALIGN(addr)        _ALIGN(addr, PAGE_SIZE)
  94
  95/*
  96 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
  97 * "kernelness", use is_kernel_addr() - it should do what you want.
  98 */
  99#define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 100
 101#ifndef __ASSEMBLY__
 102
 103#undef STRICT_MM_TYPECHECKS
 104
 105#ifdef STRICT_MM_TYPECHECKS
 106/* These are used to make use of C type-checking. */
 107
 108/* PTE level */
 109typedef struct { pte_basic_t pte; } pte_t;
 110#define pte_val(x)      ((x).pte)
 111#define __pte(x)        ((pte_t) { (x) })
 112
 113/* 64k pages additionally define a bigger "real PTE" type that gathers
 114 * the "second half" part of the PTE for pseudo 64k pages
 115 */
 116#ifdef CONFIG_PPC_64K_PAGES
 117typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 118#else
 119typedef struct { pte_t pte; } real_pte_t;
 120#endif
 121
 122/* PMD level */
 123#ifdef CONFIG_PPC64
 124typedef struct { unsigned long pmd; } pmd_t;
 125#define pmd_val(x)      ((x).pmd)
 126#define __pmd(x)        ((pmd_t) { (x) })
 127
 128/* PUD level exusts only on 4k pages */
 129#ifndef CONFIG_PPC_64K_PAGES
 130typedef struct { unsigned long pud; } pud_t;
 131#define pud_val(x)      ((x).pud)
 132#define __pud(x)        ((pud_t) { (x) })
 133#endif /* !CONFIG_PPC_64K_PAGES */
 134#endif /* CONFIG_PPC64 */
 135
 136/* PGD level */
 137typedef struct { unsigned long pgd; } pgd_t;
 138#define pgd_val(x)      ((x).pgd)
 139#define __pgd(x)        ((pgd_t) { (x) })
 140
 141/* Page protection bits */
 142typedef struct { unsigned long pgprot; } pgprot_t;
 143#define pgprot_val(x)   ((x).pgprot)
 144#define __pgprot(x)     ((pgprot_t) { (x) })
 145
 146#else
 147
 148/*
 149 * .. while these make it easier on the compiler
 150 */
 151
 152typedef pte_basic_t pte_t;
 153#define pte_val(x)      (x)
 154#define __pte(x)        (x)
 155
 156#ifdef CONFIG_PPC_64K_PAGES
 157typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 158#else
 159typedef unsigned long real_pte_t;
 160#endif
 161
 162
 163#ifdef CONFIG_PPC64
 164typedef unsigned long pmd_t;
 165#define pmd_val(x)      (x)
 166#define __pmd(x)        (x)
 167
 168#ifndef CONFIG_PPC_64K_PAGES
 169typedef unsigned long pud_t;
 170#define pud_val(x)      (x)
 171#define __pud(x)        (x)
 172#endif /* !CONFIG_PPC_64K_PAGES */
 173#endif /* CONFIG_PPC64 */
 174
 175typedef unsigned long pgd_t;
 176#define pgd_val(x)      (x)
 177#define pgprot_val(x)   (x)
 178
 179typedef unsigned long pgprot_t;
 180#define __pgd(x)        (x)
 181#define __pgprot(x)     (x)
 182
 183#endif
 184
 185struct page;
 186extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 187extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 188                struct page *p);
 189extern int page_is_ram(unsigned long pfn);
 190
 191struct vm_area_struct;
 192
 193typedef struct page *pgtable_t;
 194
 195#include <asm-generic/memory_model.h>
 196#endif /* __ASSEMBLY__ */
 197
 198#endif /* _ASM_POWERPC_PAGE_H */
 199