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 #ifdef __KERNEL__
  14 #include <asm/asm-compat.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 #ifdef CONFIG_CRASH_DUMP
  55 /* Kdump kernel runs at 32 MB, change at your peril. */
  56 #define PHYSICAL_START  0x2000000
  57 #else
  58 #define PHYSICAL_START  0x0
  59 #endif
  60
  61 #define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
  62 #define KERNELBASE      (PAGE_OFFSET + PHYSICAL_START)
  63
  64 #ifdef CONFIG_DISCONTIGMEM
  65 #define page_to_pfn(page)       discontigmem_page_to_pfn(page)
  66 #define pfn_to_page(pfn)        discontigmem_pfn_to_page(pfn)
  67 #define pfn_valid(pfn)          discontigmem_pfn_valid(pfn)
  68 #endif
  69
  70 #ifdef CONFIG_FLATMEM
  71 #define pfn_valid(pfn)          ((pfn) < max_mapnr)
  72 #endif
  73
  74 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  75 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
  76 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  77
  78 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
  79 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
  80
  81 /*
  82  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
  83  * and needs to be executable.  This means the whole heap ends
  84  * up being executable.
  85  */
  86 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
  87                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  88
  89 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
  90                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  91
  92 #ifdef __powerpc64__
  93 #include <asm/page_64.h>
  94 #else
  95 #include <asm/page_32.h>
  96 #endif
  97
  98 /* align addr on a size boundary - adjust address up/down if needed */
  99 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
 100 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
 101
 102 /* align addr on a size boundary - adjust address up if needed */
 103 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
 104
 105 /* to align the pointer to the (next) page boundary */
 106 #define PAGE_ALIGN(addr)        _ALIGN(addr, PAGE_SIZE)
 107
 108 /*
 109  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 110  * "kernelness", use is_kernel_addr() - it should do what you want.
 111  */
 112 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 113
 114 #ifndef __ASSEMBLY__
 115
 116 #undef STRICT_MM_TYPECHECKS
 117
 118 #ifdef STRICT_MM_TYPECHECKS
 119 /* These are used to make use of C type-checking. */
 120
 121 /* PTE level */
 122 typedef struct { pte_basic_t pte; } pte_t;
 123 #define pte_val(x)      ((x).pte)
 124 #define __pte(x)        ((pte_t) { (x) })
 125
 126 /* 64k pages additionally define a bigger "real PTE" type that gathers
 127  * the "second half" part of the PTE for pseudo 64k pages
 128  */
 129 #ifdef CONFIG_PPC_64K_PAGES
 130 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 131 #else
 132 typedef struct { pte_t pte; } real_pte_t;
 133 #endif
 134
 135 /* PMD level */
 136 typedef struct { unsigned long pmd; } pmd_t;
 137 #define pmd_val(x)      ((x).pmd)
 138 #define __pmd(x)        ((pmd_t) { (x) })
 139
 140 /* PUD level exusts only on 4k pages */
 141 #ifndef CONFIG_PPC_64K_PAGES
 142 typedef struct { unsigned long pud; } pud_t;
 143 #define pud_val(x)      ((x).pud)
 144 #define __pud(x)        ((pud_t) { (x) })
 145 #endif
 146
 147 /* PGD level */
 148 typedef struct { unsigned long pgd; } pgd_t;
 149 #define pgd_val(x)      ((x).pgd)
 150 #define __pgd(x)        ((pgd_t) { (x) })
 151
 152 /* Page protection bits */
 153 typedef struct { unsigned long pgprot; } pgprot_t;
 154 #define pgprot_val(x)   ((x).pgprot)
 155 #define __pgprot(x)     ((pgprot_t) { (x) })
 156
 157 #else
 158
 159 /*
 160  * .. while these make it easier on the compiler
 161  */
 162
 163 typedef pte_basic_t pte_t;
 164 #define pte_val(x)      (x)
 165 #define __pte(x)        (x)
 166
 167 #ifdef CONFIG_PPC_64K_PAGES
 168 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 169 #else
 170 typedef unsigned long real_pte_t;
 171 #endif
 172
 173
 174 typedef unsigned long pmd_t;
 175 #define pmd_val(x)      (x)
 176 #define __pmd(x)        (x)
 177
 178 #if defined(CONFIG_PPC64) && !defined(CONFIG_PPC_64K_PAGES)
 179 typedef unsigned long pud_t;
 180 #define pud_val(x)      (x)
 181 #define __pud(x)        (x)
 182 #endif
 183
 184 typedef unsigned long pgd_t;
 185 #define pgd_val(x)      (x)
 186 #define pgprot_val(x)   (x)
 187
 188 typedef unsigned long pgprot_t;
 189 #define __pgd(x)        (x)
 190 #define __pgprot(x)     (x)
 191
 192 #endif
 193
 194 struct page;
 195 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 196 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 197                 struct page *p);
 198 extern int page_is_ram(unsigned long pfn);
 199
 200 #include <asm-generic/memory_model.h>
 201 #endif /* __ASSEMBLY__ */
 202
 203 #endif /* __KERNEL__ */
 204
 205 #endif /* _ASM_POWERPC_PAGE_H */