arch/powerpc/include/asm/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 #ifndef __ASSEMBLY__
  14 #include <linux/types.h>
  15 #else
  16 #include <asm/types.h>
  17 #endif
  18 #include <asm/asm-compat.h>
  19 #include <asm/kdump.h>
  20
  21 /*
  22  * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
  23  * on PPC44x). For PPC64 we support either 4K or 64K software
  24  * page size. When using 64K pages however, whether we are really supporting
  25  * 64K pages in HW or not is irrelevant to those definitions.
  26  */
  27 #if defined(CONFIG_PPC_256K_PAGES)
  28 #define PAGE_SHIFT              18
  29 #elif defined(CONFIG_PPC_64K_PAGES)
  30 #define PAGE_SHIFT              16
  31 #elif defined(CONFIG_PPC_16K_PAGES)
  32 #define PAGE_SHIFT              14
  33 #else
  34 #define PAGE_SHIFT              12
  35 #endif
  36
  37 #define PAGE_SIZE               (ASM_CONST(1) << PAGE_SHIFT)
  38
  39 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
  40 #define __HAVE_ARCH_GATE_AREA           1
  41
  42 /*
  43  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  44  * assign PAGE_MASK to a larger type it gets extended the way we want
  45  * (i.e. with 1s in the high bits)
  46  */
  47 #define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
  48
  49 /*
  50  * KERNELBASE is the virtual address of the start of the kernel, it's often
  51  * the same as PAGE_OFFSET, but _might not be_.
  52  *
  53  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  54  *
  55  * PAGE_OFFSET is the virtual address of the start of lowmem.
  56  *
  57  * PHYSICAL_START is the physical address of the start of the kernel.
  58  *
  59  * MEMORY_START is the physical address of the start of lowmem.
  60  *
  61  * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
  62  * ppc32 and based on how they are set we determine MEMORY_START.
  63  *
  64  * For the linear mapping the following equation should be true:
  65  * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
  66  *
  67  * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
  68  *
  69  * There are two was to determine a physical address from a virtual one:
  70  * va = pa + PAGE_OFFSET - MEMORY_START
  71  * va = pa + KERNELBASE - PHYSICAL_START
  72  *
  73  * If you want to know something's offset from the start of the kernel you
  74  * should subtract KERNELBASE.
  75  *
  76  * If you want to test if something's a kernel address, use is_kernel_addr().
  77  */
  78
  79 #define KERNELBASE      ASM_CONST(CONFIG_KERNEL_START)
  80 #define PAGE_OFFSET     ASM_CONST(CONFIG_PAGE_OFFSET)
  81 #define LOAD_OFFSET     ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
  82
  83 #if defined(CONFIG_RELOCATABLE)
  84 #ifndef __ASSEMBLY__
  85
  86 extern phys_addr_t memstart_addr;
  87 extern phys_addr_t kernstart_addr;
  88 #endif
  89 #define PHYSICAL_START  kernstart_addr
  90 #else
  91 #define PHYSICAL_START  ASM_CONST(CONFIG_PHYSICAL_START)
  92 #endif
  93
  94 #ifdef CONFIG_PPC64
  95 #define MEMORY_START    0UL
  96 #elif defined(CONFIG_RELOCATABLE)
  97 #define MEMORY_START    memstart_addr
  98 #else
  99 #define MEMORY_START    (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
 100 #endif
 101
 102 #ifdef CONFIG_FLATMEM
 103 #define ARCH_PFN_OFFSET         (MEMORY_START >> PAGE_SHIFT)
 104 #define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
 105 #endif
 106
 107 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 108 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 109 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 110
 111 #define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - MEMORY_START))
 112 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
 113
 114 /*
 115  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
 116  * and needs to be executable.  This means the whole heap ends
 117  * up being executable.
 118  */
 119 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
 120                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 121
 122 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
 123                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 124
 125 #ifdef __powerpc64__
 126 #include <asm/page_64.h>
 127 #else
 128 #include <asm/page_32.h>
 129 #endif
 130
 131 /* align addr on a size boundary - adjust address up/down if needed */
 132 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
 133 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
 134
 135 /* align addr on a size boundary - adjust address up if needed */
 136 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
 137
 138 /*
 139  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 140  * "kernelness", use is_kernel_addr() - it should do what you want.
 141  */
 142 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 143
 144 #ifndef __ASSEMBLY__
 145
 146 #undef STRICT_MM_TYPECHECKS
 147
 148 #ifdef STRICT_MM_TYPECHECKS
 149 /* These are used to make use of C type-checking. */
 150
 151 /* PTE level */
 152 typedef struct { pte_basic_t pte; } pte_t;
 153 #define pte_val(x)      ((x).pte)
 154 #define __pte(x)        ((pte_t) { (x) })
 155
 156 /* 64k pages additionally define a bigger "real PTE" type that gathers
 157  * the "second half" part of the PTE for pseudo 64k pages
 158  */
 159 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 160 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 161 #else
 162 typedef struct { pte_t pte; } real_pte_t;
 163 #endif
 164
 165 /* PMD level */
 166 #ifdef CONFIG_PPC64
 167 typedef struct { unsigned long pmd; } pmd_t;
 168 #define pmd_val(x)      ((x).pmd)
 169 #define __pmd(x)        ((pmd_t) { (x) })
 170
 171 /* PUD level exusts only on 4k pages */
 172 #ifndef CONFIG_PPC_64K_PAGES
 173 typedef struct { unsigned long pud; } pud_t;
 174 #define pud_val(x)      ((x).pud)
 175 #define __pud(x)        ((pud_t) { (x) })
 176 #endif /* !CONFIG_PPC_64K_PAGES */
 177 #endif /* CONFIG_PPC64 */
 178
 179 /* PGD level */
 180 typedef struct { unsigned long pgd; } pgd_t;
 181 #define pgd_val(x)      ((x).pgd)
 182 #define __pgd(x)        ((pgd_t) { (x) })
 183
 184 /* Page protection bits */
 185 typedef struct { unsigned long pgprot; } pgprot_t;
 186 #define pgprot_val(x)   ((x).pgprot)
 187 #define __pgprot(x)     ((pgprot_t) { (x) })
 188
 189 #else
 190
 191 /*
 192  * .. while these make it easier on the compiler
 193  */
 194
 195 typedef pte_basic_t pte_t;
 196 #define pte_val(x)      (x)
 197 #define __pte(x)        (x)
 198
 199 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 200 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 201 #else
 202 typedef pte_t real_pte_t;
 203 #endif
 204
 205
 206 #ifdef CONFIG_PPC64
 207 typedef unsigned long pmd_t;
 208 #define pmd_val(x)      (x)
 209 #define __pmd(x)        (x)
 210
 211 #ifndef CONFIG_PPC_64K_PAGES
 212 typedef unsigned long pud_t;
 213 #define pud_val(x)      (x)
 214 #define __pud(x)        (x)
 215 #endif /* !CONFIG_PPC_64K_PAGES */
 216 #endif /* CONFIG_PPC64 */
 217
 218 typedef unsigned long pgd_t;
 219 #define pgd_val(x)      (x)
 220 #define pgprot_val(x)   (x)
 221
 222 typedef unsigned long pgprot_t;
 223 #define __pgd(x)        (x)
 224 #define __pgprot(x)     (x)
 225
 226 #endif
 227
 228 struct page;
 229 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 230 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 231                 struct page *p);
 232 extern int page_is_ram(unsigned long pfn);
 233
 234 struct vm_area_struct;
 235
 236 typedef struct page *pgtable_t;
 237
 238 #include <asm-generic/memory_model.h>
 239 #endif /* __ASSEMBLY__ */
 240
 241 #endif /* _ASM_POWERPC_PAGE_H */