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 #define PAGE_OFFSET     ASM_CONST(CONFIG_KERNEL_START)
  41 #define KERNELBASE      PAGE_OFFSET
  42
  43 #ifdef CONFIG_DISCONTIGMEM
  44 #define page_to_pfn(page)       discontigmem_page_to_pfn(page)
  45 #define pfn_to_page(pfn)        discontigmem_pfn_to_page(pfn)
  46 #define pfn_valid(pfn)          discontigmem_pfn_valid(pfn)
  47 #endif
  48
  49 #ifdef CONFIG_FLATMEM
  50 #define pfn_to_page(pfn)        (mem_map + (pfn))
  51 #define page_to_pfn(page)       ((unsigned long)((page) - mem_map))
  52 #define pfn_valid(pfn)          ((pfn) < max_mapnr)
  53 #endif
  54
  55 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  56 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
  57 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  58
  59 #define __va(x) ((void *)((unsigned long)(x) + KERNELBASE))
  60 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
  61
  62 /*
  63  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
  64  * and needs to be executable.  This means the whole heap ends
  65  * up being executable.
  66  */
  67 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
  68                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  69
  70 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
  71                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
  72
  73 #ifdef __powerpc64__
  74 #include <asm/page_64.h>
  75 #else
  76 #include <asm/page_32.h>
  77 #endif
  78
  79 /* align addr on a size boundary - adjust address up/down if needed */
  80 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
  81 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
  82
  83 /* align addr on a size boundary - adjust address up if needed */
  84 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
  85
  86 /* to align the pointer to the (next) page boundary */
  87 #define PAGE_ALIGN(addr)        _ALIGN(addr, PAGE_SIZE)
  88
  89 #ifndef __ASSEMBLY__
  90
  91 #undef STRICT_MM_TYPECHECKS
  92
  93 #ifdef STRICT_MM_TYPECHECKS
  94 /* These are used to make use of C type-checking. */
  95
  96 /* PTE level */
  97 typedef struct { pte_basic_t pte; } pte_t;
  98 #define pte_val(x)      ((x).pte)
  99 #define __pte(x)        ((pte_t) { (x) })
 100
 101 /* 64k pages additionally define a bigger "real PTE" type that gathers
 102  * the "second half" part of the PTE for pseudo 64k pages
 103  */
 104 #ifdef CONFIG_PPC_64K_PAGES
 105 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 106 #else
 107 typedef struct { pte_t pte; } real_pte_t;
 108 #endif
 109
 110 /* PMD level */
 111 typedef struct { unsigned long pmd; } pmd_t;
 112 #define pmd_val(x)      ((x).pmd)
 113 #define __pmd(x)        ((pmd_t) { (x) })
 114
 115 /* PUD level exusts only on 4k pages */
 116 #ifndef CONFIG_PPC_64K_PAGES
 117 typedef struct { unsigned long pud; } pud_t;
 118 #define pud_val(x)      ((x).pud)
 119 #define __pud(x)        ((pud_t) { (x) })
 120 #endif
 121
 122 /* PGD level */
 123 typedef struct { unsigned long pgd; } pgd_t;
 124 #define pgd_val(x)      ((x).pgd)
 125 #define __pgd(x)        ((pgd_t) { (x) })
 126
 127 /* Page protection bits */
 128 typedef struct { unsigned long pgprot; } pgprot_t;
 129 #define pgprot_val(x)   ((x).pgprot)
 130 #define __pgprot(x)     ((pgprot_t) { (x) })
 131
 132 #else
 133
 134 /*
 135  * .. while these make it easier on the compiler
 136  */
 137
 138 typedef pte_basic_t pte_t;
 139 #define pte_val(x)      (x)
 140 #define __pte(x)        (x)
 141
 142 #ifdef CONFIG_PPC_64K_PAGES
 143 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 144 #else
 145 typedef unsigned long real_pte_t;
 146 #endif
 147
 148
 149 typedef unsigned long pmd_t;
 150 #define pmd_val(x)      (x)
 151 #define __pmd(x)        (x)
 152
 153 #ifndef CONFIG_PPC_64K_PAGES
 154 typedef unsigned long pud_t;
 155 #define pud_val(x)      (x)
 156 #define __pud(x)        (x)
 157 #endif
 158
 159 typedef unsigned long pgd_t;
 160 #define pgd_val(x)      (x)
 161 #define pgprot_val(x)   (x)
 162
 163 typedef unsigned long pgprot_t;
 164 #define __pgd(x)        (x)
 165 #define __pgprot(x)     (x)
 166
 167 #endif
 168
 169 struct page;
 170 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 171 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 172                 struct page *p);
 173 extern int page_is_ram(unsigned long pfn);
 174
 175 #endif /* __ASSEMBLY__ */
 176
 177 #endif /* __KERNEL__ */
 178
 179 #endif /* _ASM_POWERPC_PAGE_H */