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 */
 109 typedef 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
 117 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 118 #else
 119 typedef struct { pte_t pte; } real_pte_t;
 120 #endif
 121
 122 /* PMD level */
 123 #ifdef CONFIG_PPC64
 124 typedef 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
 130 typedef 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 */
 137 typedef 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 */
 142 typedef 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
 152 typedef pte_basic_t pte_t;
 153 #define pte_val(x)      (x)
 154 #define __pte(x)        (x)
 155
 156 #ifdef CONFIG_PPC_64K_PAGES
 157 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 158 #else
 159 typedef unsigned long real_pte_t;
 160 #endif
 161
 162
 163 #ifdef CONFIG_PPC64
 164 typedef unsigned long pmd_t;
 165 #define pmd_val(x)      (x)
 166 #define __pmd(x)        (x)
 167
 168 #ifndef CONFIG_PPC_64K_PAGES
 169 typedef 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
 175 typedef unsigned long pgd_t;
 176 #define pgd_val(x)      (x)
 177 #define pgprot_val(x)   (x)
 178
 179 typedef unsigned long pgprot_t;
 180 #define __pgd(x)        (x)
 181 #define __pgprot(x)     (x)
 182
 183 #endif
 184
 185 struct page;
 186 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 187 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 188                 struct page *p);
 189 extern int page_is_ram(unsigned long pfn);
 190
 191 struct vm_area_struct;
 192
 193 typedef struct page *pgtable_t;
 194
 195 #include <asm-generic/memory_model.h>
 196 #endif /* __ASSEMBLY__ */
 197
 198 #endif /* _ASM_POWERPC_PAGE_H */