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