LXR linux/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 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#ifdef CONFIG_PPC_BOOK3E_64
 143#define is_kernel_addr(x)       ((x) >= 0x8000000000000000ul)
 144#else
 145#define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 146#endif
 147
 148#ifndef __ASSEMBLY__
 149
 150#undef STRICT_MM_TYPECHECKS
 151
 152#ifdef STRICT_MM_TYPECHECKS
 153/* These are used to make use of C type-checking. */
 154
 155/* PTE level */
 156typedef struct { pte_basic_t pte; } pte_t;
 157#define pte_val(x)      ((x).pte)
 158#define __pte(x)        ((pte_t) { (x) })
 159
 160/* 64k pages additionally define a bigger "real PTE" type that gathers
 161 * the "second half" part of the PTE for pseudo 64k pages
 162 */
 163#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 164typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 165#else
 166typedef struct { pte_t pte; } real_pte_t;
 167#endif
 168
 169/* PMD level */
 170#ifdef CONFIG_PPC64
 171typedef struct { unsigned long pmd; } pmd_t;
 172#define pmd_val(x)      ((x).pmd)
 173#define __pmd(x)        ((pmd_t) { (x) })
 174
 175/* PUD level exusts only on 4k pages */
 176#ifndef CONFIG_PPC_64K_PAGES
 177typedef struct { unsigned long pud; } pud_t;
 178#define pud_val(x)      ((x).pud)
 179#define __pud(x)        ((pud_t) { (x) })
 180#endif /* !CONFIG_PPC_64K_PAGES */
 181#endif /* CONFIG_PPC64 */
 182
 183/* PGD level */
 184typedef struct { unsigned long pgd; } pgd_t;
 185#define pgd_val(x)      ((x).pgd)
 186#define __pgd(x)        ((pgd_t) { (x) })
 187
 188/* Page protection bits */
 189typedef struct { unsigned long pgprot; } pgprot_t;
 190#define pgprot_val(x)   ((x).pgprot)
 191#define __pgprot(x)     ((pgprot_t) { (x) })
 192
 193#else
 194
 195/*
 196 * .. while these make it easier on the compiler
 197 */
 198
 199typedef pte_basic_t pte_t;
 200#define pte_val(x)      (x)
 201#define __pte(x)        (x)
 202
 203#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 204typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 205#else
 206typedef pte_t real_pte_t;
 207#endif
 208
 209
 210#ifdef CONFIG_PPC64
 211typedef unsigned long pmd_t;
 212#define pmd_val(x)      (x)
 213#define __pmd(x)        (x)
 214
 215#ifndef CONFIG_PPC_64K_PAGES
 216typedef unsigned long pud_t;
 217#define pud_val(x)      (x)
 218#define __pud(x)        (x)
 219#endif /* !CONFIG_PPC_64K_PAGES */
 220#endif /* CONFIG_PPC64 */
 221
 222typedef unsigned long pgd_t;
 223#define pgd_val(x)      (x)
 224#define pgprot_val(x)   (x)
 225
 226typedef unsigned long pgprot_t;
 227#define __pgd(x)        (x)
 228#define __pgprot(x)     (x)
 229
 230#endif
 231
 232struct page;
 233extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 234extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 235                struct page *p);
 236extern int page_is_ram(unsigned long pfn);
 237
 238#ifdef CONFIG_PPC_SMLPAR
 239void arch_free_page(struct page *page, int order);
 240#define HAVE_ARCH_FREE_PAGE
 241#endif
 242
 243struct vm_area_struct;
 244
 245typedef struct page *pgtable_t;
 246
 247#include <asm-generic/memory_model.h>
 248#endif /* __ASSEMBLY__ */
 249
 250#endif /* _ASM_POWERPC_PAGE_H */
 251