LXR linux/arch/unicore32/include/asm/pgtable.h

   1/*
   2 * linux/arch/unicore32/include/asm/pgtable.h
   3 *
   4 * Code specific to PKUnity SoC and UniCore ISA
   5 *
   6 * Copyright (C) 2001-2010 GUAN Xue-tao
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12#ifndef __UNICORE_PGTABLE_H__
  13#define __UNICORE_PGTABLE_H__
  14
  15#include <asm-generic/pgtable-nopmd.h>
  16#include <asm/cpu-single.h>
  17
  18#include <asm/memory.h>
  19#include <asm/pgtable-hwdef.h>
  20
  21/*
  22 * Just any arbitrary offset to the start of the vmalloc VM area: the
  23 * current 8MB value just means that there will be a 8MB "hole" after the
  24 * physical memory until the kernel virtual memory starts.  That means that
  25 * any out-of-bounds memory accesses will hopefully be caught.
  26 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  27 * area for the same reason. ;)
  28 *
  29 * Note that platforms may override VMALLOC_START, but they must provide
  30 * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  31 * which may not overlap IO space.
  32 */
  33#ifndef VMALLOC_START
  34#define VMALLOC_OFFSET          SZ_8M
  35#define VMALLOC_START           (((unsigned long)high_memory + VMALLOC_OFFSET) \
  36                                        & ~(VMALLOC_OFFSET-1))
  37#define VMALLOC_END             (0xff000000UL)
  38#endif
  39
  40#define PTRS_PER_PTE            1024
  41#define PTRS_PER_PGD            1024
  42
  43/*
  44 * PGDIR_SHIFT determines what a third-level page table entry can map
  45 */
  46#define PGDIR_SHIFT             22
  47
  48#ifndef __ASSEMBLY__
  49extern void __pte_error(const char *file, int line, unsigned long val);
  50extern void __pgd_error(const char *file, int line, unsigned long val);
  51
  52#define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  53#define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
  54#endif /* !__ASSEMBLY__ */
  55
  56#define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  57#define PGDIR_MASK              (~(PGDIR_SIZE-1))
  58
  59/*
  60 * This is the lowest virtual address we can permit any user space
  61 * mapping to be mapped at.  This is particularly important for
  62 * non-high vector CPUs.
  63 */
  64#define FIRST_USER_ADDRESS      PAGE_SIZE
  65
  66#define FIRST_USER_PGD_NR       1
  67#define USER_PTRS_PER_PGD       ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
  68
  69/*
  70 * section address mask and size definitions.
  71 */
  72#define SECTION_SHIFT           22
  73#define SECTION_SIZE            (1UL << SECTION_SHIFT)
  74#define SECTION_MASK            (~(SECTION_SIZE-1))
  75
  76#ifndef __ASSEMBLY__
  77
  78/*
  79 * The pgprot_* and protection_map entries will be fixed up in runtime
  80 * to include the cachable bits based on memory policy, as well as any
  81 * architecture dependent bits.
  82 */
  83#define _PTE_DEFAULT            (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)
  84
  85extern pgprot_t pgprot_user;
  86extern pgprot_t pgprot_kernel;
  87
  88#define PAGE_NONE               pgprot_user
  89#define PAGE_SHARED             __pgprot(pgprot_val(pgprot_user | PTE_READ \
  90                                                                | PTE_WRITE)
  91#define PAGE_SHARED_EXEC        __pgprot(pgprot_val(pgprot_user | PTE_READ \
  92                                                                | PTE_WRITE \
  93                                                                | PTE_EXEC)
  94#define PAGE_COPY               __pgprot(pgprot_val(pgprot_user | PTE_READ)
  95#define PAGE_COPY_EXEC          __pgprot(pgprot_val(pgprot_user | PTE_READ \
  96                                                                | PTE_EXEC)
  97#define PAGE_READONLY           __pgprot(pgprot_val(pgprot_user | PTE_READ)
  98#define PAGE_READONLY_EXEC      __pgprot(pgprot_val(pgprot_user | PTE_READ \
  99                                                                | PTE_EXEC)
 100#define PAGE_KERNEL             pgprot_kernel
 101#define PAGE_KERNEL_EXEC        __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))
 102
 103#define __PAGE_NONE             __pgprot(_PTE_DEFAULT)
 104#define __PAGE_SHARED           __pgprot(_PTE_DEFAULT | PTE_READ \
 105                                                        | PTE_WRITE)
 106#define __PAGE_SHARED_EXEC      __pgprot(_PTE_DEFAULT | PTE_READ \
 107                                                        | PTE_WRITE \
 108                                                        | PTE_EXEC)
 109#define __PAGE_COPY             __pgprot(_PTE_DEFAULT | PTE_READ)
 110#define __PAGE_COPY_EXEC        __pgprot(_PTE_DEFAULT | PTE_READ \
 111                                                        | PTE_EXEC)
 112#define __PAGE_READONLY         __pgprot(_PTE_DEFAULT | PTE_READ)
 113#define __PAGE_READONLY_EXEC    __pgprot(_PTE_DEFAULT | PTE_READ \
 114                                                        | PTE_EXEC)
 115
 116#endif /* __ASSEMBLY__ */
 117
 118/*
 119 * The table below defines the page protection levels that we insert into our
 120 * Linux page table version.  These get translated into the best that the
 121 * architecture can perform.  Note that on UniCore hardware:
 122 *  1) We cannot do execute protection
 123 *  2) If we could do execute protection, then read is implied
 124 *  3) write implies read permissions
 125 */
 126#define __P000  __PAGE_NONE
 127#define __P001  __PAGE_READONLY
 128#define __P010  __PAGE_COPY
 129#define __P011  __PAGE_COPY
 130#define __P100  __PAGE_READONLY_EXEC
 131#define __P101  __PAGE_READONLY_EXEC
 132#define __P110  __PAGE_COPY_EXEC
 133#define __P111  __PAGE_COPY_EXEC
 134
 135#define __S000  __PAGE_NONE
 136#define __S001  __PAGE_READONLY
 137#define __S010  __PAGE_SHARED
 138#define __S011  __PAGE_SHARED
 139#define __S100  __PAGE_READONLY_EXEC
 140#define __S101  __PAGE_READONLY_EXEC
 141#define __S110  __PAGE_SHARED_EXEC
 142#define __S111  __PAGE_SHARED_EXEC
 143
 144#ifndef __ASSEMBLY__
 145/*
 146 * ZERO_PAGE is a global shared page that is always zero: used
 147 * for zero-mapped memory areas etc..
 148 */
 149extern struct page *empty_zero_page;
 150#define ZERO_PAGE(vaddr)                (empty_zero_page)
 151
 152#define pte_pfn(pte)                    (pte_val(pte) >> PAGE_SHIFT)
 153#define pfn_pte(pfn, prot)              (__pte(((pfn) << PAGE_SHIFT) \
 154                                                | pgprot_val(prot)))
 155
 156#define pte_none(pte)                   (!pte_val(pte))
 157#define pte_clear(mm, addr, ptep)       set_pte(ptep, __pte(0))
 158#define pte_page(pte)                   (pfn_to_page(pte_pfn(pte)))
 159#define pte_offset_kernel(dir, addr)    (pmd_page_vaddr(*(dir)) \
 160                                                + __pte_index(addr))
 161
 162#define pte_offset_map(dir, addr)       (pmd_page_vaddr(*(dir)) \
 163                                                + __pte_index(addr))
 164#define pte_unmap(pte)                  do { } while (0)
 165
 166#define set_pte(ptep, pte)      cpu_set_pte(ptep, pte)
 167
 168#define set_pte_at(mm, addr, ptep, pteval)      \
 169        do {                                    \
 170                set_pte(ptep, pteval);          \
 171        } while (0)
 172
 173/*
 174 * The following only work if pte_present() is true.
 175 * Undefined behaviour if not..
 176 */
 177#define pte_present(pte)        (pte_val(pte) & PTE_PRESENT)
 178#define pte_write(pte)          (pte_val(pte) & PTE_WRITE)
 179#define pte_dirty(pte)          (pte_val(pte) & PTE_DIRTY)
 180#define pte_young(pte)          (pte_val(pte) & PTE_YOUNG)
 181#define pte_exec(pte)           (pte_val(pte) & PTE_EXEC)
 182#define pte_special(pte)        (0)
 183
 184#define PTE_BIT_FUNC(fn, op) \
 185static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 186
 187PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
 188PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
 189PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
 190PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
 191PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
 192PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);
 193
 194static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 195
 196/*
 197 * Mark the prot value as uncacheable.
 198 */
 199#define pgprot_noncached(prot)          \
 200        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 201#define pgprot_writecombine(prot)       \
 202        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 203#define pgprot_dmacoherent(prot)        \
 204        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 205
 206#define pmd_none(pmd)           (!pmd_val(pmd))
 207#define pmd_present(pmd)        (pmd_val(pmd) & PMD_PRESENT)
 208#define pmd_bad(pmd)            (((pmd_val(pmd) &               \
 209                                (PMD_PRESENT | PMD_TYPE_MASK))  \
 210                                != (PMD_PRESENT | PMD_TYPE_TABLE)))
 211
 212#define set_pmd(pmdpd, pmdval)          \
 213        do {                            \
 214                *(pmdpd) = pmdval;      \
 215        } while (0)
 216
 217#define pmd_clear(pmdp)                 \
 218        do {                            \
 219                set_pmd(pmdp, __pmd(0));\
 220                clean_pmd_entry(pmdp);  \
 221        } while (0)
 222
 223#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
 224#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
 225
 226/*
 227 * Conversion functions: convert a page and protection to a page entry,
 228 * and a page entry and page directory to the page they refer to.
 229 */
 230#define mk_pte(page, prot)      pfn_pte(page_to_pfn(page), prot)
 231
 232/* to find an entry in a page-table-directory */
 233#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 234
 235#define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))
 236
 237/* to find an entry in a kernel page-table-directory */
 238#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 239
 240/* Find an entry in the third-level page table.. */
 241#define __pte_index(addr)       (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 242
 243static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 244{
 245        const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
 246        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 247        return pte;
 248}
 249
 250extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 251
 252/*
 253 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 254 * page tables as follows:
 255 *
 256 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 257 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
 258 *   <--------------- offset --------------> <--- type --> 0 0 0 0 0
 259 *
 260 * This gives us up to 127 swap files and 32GB per swap file.  Note that
 261 * the offset field is always non-zero.
 262 */
 263#define __SWP_TYPE_SHIFT        5
 264#define __SWP_TYPE_BITS         7
 265#define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 266#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 267
 268#define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT)          \
 269                                & __SWP_TYPE_MASK)
 270#define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 271#define __swp_entry(type, offset) ((swp_entry_t) {                      \
 272                                ((type) << __SWP_TYPE_SHIFT) |          \
 273                                ((offset) << __SWP_OFFSET_SHIFT) })
 274
 275#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 276#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 277
 278/*
 279 * It is an error for the kernel to have more swap files than we can
 280 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 281 * is increased beyond what we presently support.
 282 */
 283#define MAX_SWAPFILES_CHECK()   \
 284        BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 285
 286/*
 287 * Encode and decode a file entry.  File entries are stored in the Linux
 288 * page tables as follows:
 289 *
 290 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 291 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
 292 *   <----------------------- offset ----------------------> 1 0 0 0
 293 */
 294#define pte_file(pte)           (pte_val(pte) & PTE_FILE)
 295#define pte_to_pgoff(x)         (pte_val(x) >> 4)
 296#define pgoff_to_pte(x)         __pte(((x) << 4) | PTE_FILE)
 297
 298#define PTE_FILE_MAX_BITS       28
 299
 300/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 301/* FIXME: this is not correct */
 302#define kern_addr_valid(addr)   (1)
 303
 304#include <asm-generic/pgtable.h>
 305
 306#define pgtable_cache_init() do { } while (0)
 307
 308#endif /* !__ASSEMBLY__ */
 309
 310#endif /* __UNICORE_PGTABLE_H__ */
 311