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