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 #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) && defined(CONFIG_FLATMEM)
  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 #define MEMORY_START    memstart_addr
  81 #else
  82 #define PHYSICAL_START  ASM_CONST(CONFIG_PHYSICAL_START)
  83 #define MEMORY_START    (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
  84 #endif
  85
  86 #ifdef CONFIG_FLATMEM
  87 #define ARCH_PFN_OFFSET         (MEMORY_START >> PAGE_SHIFT)
  88 #define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr))
  89 #endif
  90
  91 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
  92 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
  93 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
  94
  95 #define __va(x) ((void *)((unsigned long)(x) - PHYSICAL_START + KERNELBASE))
  96 #define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
  97
  98 /*
  99  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
 100  * and needs to be executable.  This means the whole heap ends
 101  * up being executable.
 102  */
 103 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
 104                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 105
 106 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
 107                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 108
 109 #ifdef __powerpc64__
 110 #include <asm/page_64.h>
 111 #else
 112 #include <asm/page_32.h>
 113 #endif
 114
 115 /* align addr on a size boundary - adjust address up/down if needed */
 116 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
 117 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
 118
 119 /* align addr on a size boundary - adjust address up if needed */
 120 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
 121
 122 /*
 123  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 124  * "kernelness", use is_kernel_addr() - it should do what you want.
 125  */
 126 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 127
 128 #ifndef __ASSEMBLY__
 129
 130 #undef STRICT_MM_TYPECHECKS
 131
 132 #ifdef STRICT_MM_TYPECHECKS
 133 /* These are used to make use of C type-checking. */
 134
 135 /* PTE level */
 136 typedef struct { pte_basic_t pte; } pte_t;
 137 #define pte_val(x)      ((x).pte)
 138 #define __pte(x)        ((pte_t) { (x) })
 139
 140 /* 64k pages additionally define a bigger "real PTE" type that gathers
 141  * the "second half" part of the PTE for pseudo 64k pages
 142  */
 143 #ifdef CONFIG_PPC_64K_PAGES
 144 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 145 #else
 146 typedef struct { pte_t pte; } real_pte_t;
 147 #endif
 148
 149 /* PMD level */
 150 #ifdef CONFIG_PPC64
 151 typedef struct { unsigned long pmd; } pmd_t;
 152 #define pmd_val(x)      ((x).pmd)
 153 #define __pmd(x)        ((pmd_t) { (x) })
 154
 155 /* PUD level exusts only on 4k pages */
 156 #ifndef CONFIG_PPC_64K_PAGES
 157 typedef struct { unsigned long pud; } pud_t;
 158 #define pud_val(x)      ((x).pud)
 159 #define __pud(x)        ((pud_t) { (x) })
 160 #endif /* !CONFIG_PPC_64K_PAGES */
 161 #endif /* CONFIG_PPC64 */
 162
 163 /* PGD level */
 164 typedef struct { unsigned long pgd; } pgd_t;
 165 #define pgd_val(x)      ((x).pgd)
 166 #define __pgd(x)        ((pgd_t) { (x) })
 167
 168 /* Page protection bits */
 169 typedef struct { unsigned long pgprot; } pgprot_t;
 170 #define pgprot_val(x)   ((x).pgprot)
 171 #define __pgprot(x)     ((pgprot_t) { (x) })
 172
 173 #else
 174
 175 /*
 176  * .. while these make it easier on the compiler
 177  */
 178
 179 typedef pte_basic_t pte_t;
 180 #define pte_val(x)      (x)
 181 #define __pte(x)        (x)
 182
 183 #ifdef CONFIG_PPC_64K_PAGES
 184 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 185 #else
 186 typedef unsigned long real_pte_t;
 187 #endif
 188
 189
 190 #ifdef CONFIG_PPC64
 191 typedef unsigned long pmd_t;
 192 #define pmd_val(x)      (x)
 193 #define __pmd(x)        (x)
 194
 195 #ifndef CONFIG_PPC_64K_PAGES
 196 typedef unsigned long pud_t;
 197 #define pud_val(x)      (x)
 198 #define __pud(x)        (x)
 199 #endif /* !CONFIG_PPC_64K_PAGES */
 200 #endif /* CONFIG_PPC64 */
 201
 202 typedef unsigned long pgd_t;
 203 #define pgd_val(x)      (x)
 204 #define pgprot_val(x)   (x)
 205
 206 typedef unsigned long pgprot_t;
 207 #define __pgd(x)        (x)
 208 #define __pgprot(x)     (x)
 209
 210 #endif
 211
 212 struct page;
 213 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 214 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 215                 struct page *p);
 216 extern int page_is_ram(unsigned long pfn);
 217
 218 struct vm_area_struct;
 219
 220 typedef struct page *pgtable_t;
 221
 222 #include <asm-generic/memory_model.h>
 223 #endif /* __ASSEMBLY__ */
 224
 225 #endif /* _ASM_POWERPC_PAGE_H */