linux/arch/powerpc/include/asm/page.h
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   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
  86extern phys_addr_t memstart_addr;
  87extern 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 */
 152typedef 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)
 160typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 161#else
 162typedef struct { pte_t pte; } real_pte_t;
 163#endif
 164
 165/* PMD level */
 166#ifdef CONFIG_PPC64
 167typedef 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
 173typedef 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 */
 180typedef 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 */
 185typedef 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
 195typedef 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)
 200typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 201#else
 202typedef pte_t real_pte_t;
 203#endif
 204
 205
 206#ifdef CONFIG_PPC64
 207typedef unsigned long pmd_t;
 208#define pmd_val(x)      (x)
 209#define __pmd(x)        (x)
 210
 211#ifndef CONFIG_PPC_64K_PAGES
 212typedef 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
 218typedef unsigned long pgd_t;
 219#define pgd_val(x)      (x)
 220#define pgprot_val(x)   (x)
 221
 222typedef unsigned long pgprot_t;
 223#define __pgd(x)        (x)
 224#define __pgprot(x)     (x)
 225
 226#endif
 227
 228struct page;
 229extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 230extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 231                struct page *p);
 232extern int page_is_ram(unsigned long pfn);
 233
 234struct vm_area_struct;
 235
 236typedef struct page *pgtable_t;
 237
 238#include <asm-generic/memory_model.h>
 239#endif /* __ASSEMBLY__ */
 240
 241#endif /* _ASM_POWERPC_PAGE_H */
 242