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 <linux/config.h>
  15 #include <asm/asm-compat.h>
  16
  17 /*
  18  * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software
  19  * page size. When using 64K pages however, whether we are really supporting
  20  * 64K pages in HW or not is irrelevant to those definitions.
  21  */
  22 #ifdef CONFIG_PPC_64K_PAGES
  23 #define PAGE_SHIFT              16
  24 #else
  25 #define PAGE_SHIFT              12
  26 #endif
  27
  28 #define PAGE_SIZE               (ASM_CONST(1) << PAGE_SHIFT)
  29
  30 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
  31 #define __HAVE_ARCH_GATE_AREA           1
  32
  33 /*
  34  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  35  * assign PAGE_MASK to a larger type it gets extended the way we want
  36  * (i.e. with 1s in the high bits)
  37  */
  38 #define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
  39
  40 /*
  41  * KERNELBASE is the virtual address of the start of the kernel, it's often
  42  * the same as PAGE_OFFSET, but _might not be_.
  43  *
  44  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  45  *
  46  * To get a physical address from a virtual one you subtract PAGE_OFFSET,
  47  * _not_ KERNELBASE.
  48  *
  49  * If you want to know something's offset from the start of the kernel you
  50  * should subtract KERNELBASE.
  51  *
  52  * If you want to test if something's a kernel address, use is_kernel_addr().
  53  */
  54
  55 #ifdef CONFIG_CRASH_DUMP
  56 /* Kdump kernel runs at 32 MB, change at your peril. */
  57 #define PHYSICAL_START  0x2000000
  58 #else
  59 #define PHYSICAL_START  0x0
  60 #endif
  61
  62 #define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
  63 #define KERNELBASE      (PAGE_OFFSET + PHYSICAL_START)
  64
  65 #ifdef CONFIG_DISCONTIGMEM
  66 #define page_to_pfn(page)       discontigmem_page_to_pfn(page)
  67 #define pfn_to_page(pfn)        discontigmem_pfn_to_page(pfn)
  68 #define pfn_valid(pfn)          discontigmem_pfn_valid(pfn)
  69 #endif
  70
  71 #ifdef CONFIG_FLATMEM
  72 #define pfn_to_page(pfn)        (mem_map + (pfn))
  73 #define page_to_pfn(page)       ((unsigned long)((page) - mem_map))
  74 #define pfn_valid(pfn)          ((pfn) < max_mapnr)
  75 #endif
  76
  77 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  78 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
  79 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  80
  81 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
  82 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
  83
  84 /*
  85  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
  86  * and needs to be executable.  This means the whole heap ends
  87  * up being executable.
  88  */
  89 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
  90                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  91
  92 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
  93                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  94
  95 #ifdef __powerpc64__
  96 #include <asm/page_64.h>
  97 #else
  98 #include <asm/page_32.h>
  99 #endif
 100
 101 /* align addr on a size boundary - adjust address up/down if needed */
 102 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
 103 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
 104
 105 /* align addr on a size boundary - adjust address up if needed */
 106 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
 107
 108 /* to align the pointer to the (next) page boundary */
 109 #define PAGE_ALIGN(addr)        _ALIGN(addr, PAGE_SIZE)
 110
 111 /*
 112  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 113  * "kernelness", use is_kernel_addr() - it should do what you want.
 114  */
 115 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 116
 117 #ifndef __ASSEMBLY__
 118
 119 #undef STRICT_MM_TYPECHECKS
 120
 121 #ifdef STRICT_MM_TYPECHECKS
 122 /* These are used to make use of C type-checking. */
 123
 124 /* PTE level */
 125 typedef struct { pte_basic_t pte; } pte_t;
 126 #define pte_val(x)      ((x).pte)
 127 #define __pte(x)        ((pte_t) { (x) })
 128
 129 /* 64k pages additionally define a bigger "real PTE" type that gathers
 130  * the "second half" part of the PTE for pseudo 64k pages
 131  */
 132 #ifdef CONFIG_PPC_64K_PAGES
 133 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 134 #else
 135 typedef struct { pte_t pte; } real_pte_t;
 136 #endif
 137
 138 /* PMD level */
 139 typedef struct { unsigned long pmd; } pmd_t;
 140 #define pmd_val(x)      ((x).pmd)
 141 #define __pmd(x)        ((pmd_t) { (x) })
 142
 143 /* PUD level exusts only on 4k pages */
 144 #ifndef CONFIG_PPC_64K_PAGES
 145 typedef struct { unsigned long pud; } pud_t;
 146 #define pud_val(x)      ((x).pud)
 147 #define __pud(x)        ((pud_t) { (x) })
 148 #endif
 149
 150 /* PGD level */
 151 typedef struct { unsigned long pgd; } pgd_t;
 152 #define pgd_val(x)      ((x).pgd)
 153 #define __pgd(x)        ((pgd_t) { (x) })
 154
 155 /* Page protection bits */
 156 typedef struct { unsigned long pgprot; } pgprot_t;
 157 #define pgprot_val(x)   ((x).pgprot)
 158 #define __pgprot(x)     ((pgprot_t) { (x) })
 159
 160 #else
 161
 162 /*
 163  * .. while these make it easier on the compiler
 164  */
 165
 166 typedef pte_basic_t pte_t;
 167 #define pte_val(x)      (x)
 168 #define __pte(x)        (x)
 169
 170 #ifdef CONFIG_PPC_64K_PAGES
 171 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 172 #else
 173 typedef unsigned long real_pte_t;
 174 #endif
 175
 176
 177 typedef unsigned long pmd_t;
 178 #define pmd_val(x)      (x)
 179 #define __pmd(x)        (x)
 180
 181 #if defined(CONFIG_PPC64) && !defined(CONFIG_PPC_64K_PAGES)
 182 typedef unsigned long pud_t;
 183 #define pud_val(x)      (x)
 184 #define __pud(x)        (x)
 185 #endif
 186
 187 typedef unsigned long pgd_t;
 188 #define pgd_val(x)      (x)
 189 #define pgprot_val(x)   (x)
 190
 191 typedef unsigned long pgprot_t;
 192 #define __pgd(x)        (x)
 193 #define __pgprot(x)     (x)
 194
 195 #endif
 196
 197 struct page;
 198 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 199 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 200                 struct page *p);
 201 extern int page_is_ram(unsigned long pfn);
 202
 203 #endif /* __ASSEMBLY__ */
 204
 205 #endif /* __KERNEL__ */
 206
 207 #endif /* _ASM_POWERPC_PAGE_H */