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