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