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 #ifndef __ASSEMBLY__
  40 #ifdef CONFIG_HUGETLB_PAGE
  41 extern unsigned int HPAGE_SHIFT;
  42 #else
  43 #define HPAGE_SHIFT PAGE_SHIFT
  44 #endif
  45 #define HPAGE_SIZE              ((1UL) << HPAGE_SHIFT)
  46 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
  47 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
  48 #define HUGE_MAX_HSTATE         (MMU_PAGE_COUNT-1)
  49 #endif
  50
  51 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
  52 #define __HAVE_ARCH_GATE_AREA           1
  53
  54 /*
  55  * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
  56  * assign PAGE_MASK to a larger type it gets extended the way we want
  57  * (i.e. with 1s in the high bits)
  58  */
  59 #define PAGE_MASK      (~((1 << PAGE_SHIFT) - 1))
  60
  61 /*
  62  * KERNELBASE is the virtual address of the start of the kernel, it's often
  63  * the same as PAGE_OFFSET, but _might not be_.
  64  *
  65  * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
  66  *
  67  * PAGE_OFFSET is the virtual address of the start of lowmem.
  68  *
  69  * PHYSICAL_START is the physical address of the start of the kernel.
  70  *
  71  * MEMORY_START is the physical address of the start of lowmem.
  72  *
  73  * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
  74  * ppc32 and based on how they are set we determine MEMORY_START.
  75  *
  76  * For the linear mapping the following equation should be true:
  77  * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
  78  *
  79  * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
  80  *
  81  * There are two was to determine a physical address from a virtual one:
  82  * va = pa + PAGE_OFFSET - MEMORY_START
  83  * va = pa + KERNELBASE - PHYSICAL_START
  84  *
  85  * If you want to know something's offset from the start of the kernel you
  86  * should subtract KERNELBASE.
  87  *
  88  * If you want to test if something's a kernel address, use is_kernel_addr().
  89  */
  90
  91 #define KERNELBASE      ASM_CONST(CONFIG_KERNEL_START)
  92 #define PAGE_OFFSET     ASM_CONST(CONFIG_PAGE_OFFSET)
  93 #define LOAD_OFFSET     ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
  94
  95 #if defined(CONFIG_RELOCATABLE)
  96 #ifndef __ASSEMBLY__
  97
  98 extern phys_addr_t memstart_addr;
  99 extern phys_addr_t kernstart_addr;
 100 #endif
 101 #define PHYSICAL_START  kernstart_addr
 102 #else
 103 #define PHYSICAL_START  ASM_CONST(CONFIG_PHYSICAL_START)
 104 #endif
 105
 106 #ifdef CONFIG_PPC64
 107 #define MEMORY_START    0UL
 108 #elif defined(CONFIG_RELOCATABLE)
 109 #define MEMORY_START    memstart_addr
 110 #else
 111 #define MEMORY_START    (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
 112 #endif
 113
 114 #ifdef CONFIG_FLATMEM
 115 #define ARCH_PFN_OFFSET         ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
 116 #define pfn_valid(pfn)          ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
 117 #endif
 118
 119 #define virt_to_page(kaddr)     pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 120 #define pfn_to_kaddr(pfn)       __va((pfn) << PAGE_SHIFT)
 121 #define virt_addr_valid(kaddr)  pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
 122
 123 /*
 124  * On Book-E parts we need __va to parse the device tree and we can't
 125  * determine MEMORY_START until then.  However we can determine PHYSICAL_START
 126  * from information at hand (program counter, TLB lookup).
 127  *
 128  * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
 129  * the other definitions for __va & __pa.
 130  */
 131 #ifdef CONFIG_BOOKE
 132 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) - PHYSICAL_START + KERNELBASE))
 133 #define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE)
 134 #else
 135 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
 136 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
 137 #endif
 138
 139 /*
 140  * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
 141  * and needs to be executable.  This means the whole heap ends
 142  * up being executable.
 143  */
 144 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
 145                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 146
 147 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
 148                                  VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 149
 150 #ifdef __powerpc64__
 151 #include <asm/page_64.h>
 152 #else
 153 #include <asm/page_32.h>
 154 #endif
 155
 156 /* align addr on a size boundary - adjust address up/down if needed */
 157 #define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
 158 #define _ALIGN_DOWN(addr,size)  ((addr)&(~((size)-1)))
 159
 160 /* align addr on a size boundary - adjust address up if needed */
 161 #define _ALIGN(addr,size)     _ALIGN_UP(addr,size)
 162
 163 /*
 164  * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
 165  * "kernelness", use is_kernel_addr() - it should do what you want.
 166  */
 167 #ifdef CONFIG_PPC_BOOK3E_64
 168 #define is_kernel_addr(x)       ((x) >= 0x8000000000000000ul)
 169 #else
 170 #define is_kernel_addr(x)       ((x) >= PAGE_OFFSET)
 171 #endif
 172
 173 /*
 174  * Use the top bit of the higher-level page table entries to indicate whether
 175  * the entries we point to contain hugepages.  This works because we know that
 176  * the page tables live in kernel space.  If we ever decide to support having
 177  * page tables at arbitrary addresses, this breaks and will have to change.
 178  */
 179 #ifdef CONFIG_PPC64
 180 #define PD_HUGE 0x8000000000000000
 181 #else
 182 #define PD_HUGE 0x80000000
 183 #endif
 184
 185 /*
 186  * Some number of bits at the level of the page table that points to
 187  * a hugepte are used to encode the size.  This masks those bits.
 188  */
 189 #define HUGEPD_SHIFT_MASK     0x3f
 190
 191 #ifndef __ASSEMBLY__
 192
 193 #undef STRICT_MM_TYPECHECKS
 194
 195 #ifdef STRICT_MM_TYPECHECKS
 196 /* These are used to make use of C type-checking. */
 197
 198 /* PTE level */
 199 typedef struct { pte_basic_t pte; } pte_t;
 200 #define pte_val(x)      ((x).pte)
 201 #define __pte(x)        ((pte_t) { (x) })
 202
 203 /* 64k pages additionally define a bigger "real PTE" type that gathers
 204  * the "second half" part of the PTE for pseudo 64k pages
 205  */
 206 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 207 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 208 #else
 209 typedef struct { pte_t pte; } real_pte_t;
 210 #endif
 211
 212 /* PMD level */
 213 #ifdef CONFIG_PPC64
 214 typedef struct { unsigned long pmd; } pmd_t;
 215 #define pmd_val(x)      ((x).pmd)
 216 #define __pmd(x)        ((pmd_t) { (x) })
 217
 218 /* PUD level exusts only on 4k pages */
 219 #ifndef CONFIG_PPC_64K_PAGES
 220 typedef struct { unsigned long pud; } pud_t;
 221 #define pud_val(x)      ((x).pud)
 222 #define __pud(x)        ((pud_t) { (x) })
 223 #endif /* !CONFIG_PPC_64K_PAGES */
 224 #endif /* CONFIG_PPC64 */
 225
 226 /* PGD level */
 227 typedef struct { unsigned long pgd; } pgd_t;
 228 #define pgd_val(x)      ((x).pgd)
 229 #define __pgd(x)        ((pgd_t) { (x) })
 230
 231 /* Page protection bits */
 232 typedef struct { unsigned long pgprot; } pgprot_t;
 233 #define pgprot_val(x)   ((x).pgprot)
 234 #define __pgprot(x)     ((pgprot_t) { (x) })
 235
 236 #else
 237
 238 /*
 239  * .. while these make it easier on the compiler
 240  */
 241
 242 typedef pte_basic_t pte_t;
 243 #define pte_val(x)      (x)
 244 #define __pte(x)        (x)
 245
 246 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
 247 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
 248 #else
 249 typedef pte_t real_pte_t;
 250 #endif
 251
 252
 253 #ifdef CONFIG_PPC64
 254 typedef unsigned long pmd_t;
 255 #define pmd_val(x)      (x)
 256 #define __pmd(x)        (x)
 257
 258 #ifndef CONFIG_PPC_64K_PAGES
 259 typedef unsigned long pud_t;
 260 #define pud_val(x)      (x)
 261 #define __pud(x)        (x)
 262 #endif /* !CONFIG_PPC_64K_PAGES */
 263 #endif /* CONFIG_PPC64 */
 264
 265 typedef unsigned long pgd_t;
 266 #define pgd_val(x)      (x)
 267 #define pgprot_val(x)   (x)
 268
 269 typedef unsigned long pgprot_t;
 270 #define __pgd(x)        (x)
 271 #define __pgprot(x)     (x)
 272
 273 #endif
 274
 275 typedef struct { signed long pd; } hugepd_t;
 276
 277 #ifdef CONFIG_HUGETLB_PAGE
 278 static inline int hugepd_ok(hugepd_t hpd)
 279 {
 280         return (hpd.pd > 0);
 281 }
 282
 283 #define is_hugepd(pdep)               (hugepd_ok(*((hugepd_t *)(pdep))))
 284 #else /* CONFIG_HUGETLB_PAGE */
 285 #define is_hugepd(pdep)                 0
 286 #endif /* CONFIG_HUGETLB_PAGE */
 287
 288 struct page;
 289 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
 290 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
 291                 struct page *p);
 292 extern int page_is_ram(unsigned long pfn);
 293
 294 #ifdef CONFIG_PPC_SMLPAR
 295 void arch_free_page(struct page *page, int order);
 296 #define HAVE_ARCH_FREE_PAGE
 297 #endif
 298
 299 struct vm_area_struct;
 300
 301 typedef struct page *pgtable_t;
 302
 303 #include <asm-generic/memory_model.h>
 304 #endif /* __ASSEMBLY__ */
 305
 306 #endif /* _ASM_POWERPC_PAGE_H */