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