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#define __ARCH_USE_5LEVEL_HACK
  16#include <asm-generic/pgtable-nopmd.h>
  17#include <asm/cpu-single.h>
  18
  19#include <asm/memory.h>
  20#include <asm/pgtable-hwdef.h>
  21
  22/*
  23 * Just any arbitrary offset to the start of the vmalloc VM area: the
  24 * current 8MB value just means that there will be a 8MB "hole" after the
  25 * physical memory until the kernel virtual memory starts.  That means that
  26 * any out-of-bounds memory accesses will hopefully be caught.
  27 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  28 * area for the same reason. ;)
  29 *
  30 * Note that platforms may override VMALLOC_START, but they must provide
  31 * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  32 * which may not overlap IO space.
  33 */
  34#ifndef VMALLOC_START
  35#define VMALLOC_OFFSET          SZ_8M
  36#define VMALLOC_START           (((unsigned long)high_memory + VMALLOC_OFFSET) \
  37                                        & ~(VMALLOC_OFFSET-1))
  38#define VMALLOC_END             (0xff000000UL)
  39#endif
  40
  41#define PTRS_PER_PTE            1024
  42#define PTRS_PER_PGD            1024
  43
  44/*
  45 * PGDIR_SHIFT determines what a third-level page table entry can map
  46 */
  47#define PGDIR_SHIFT             22
  48
  49#ifndef __ASSEMBLY__
  50extern void __pte_error(const char *file, int line, unsigned long val);
  51extern void __pgd_error(const char *file, int line, unsigned long val);
  52
  53#define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  54#define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
  55#endif /* !__ASSEMBLY__ */
  56
  57#define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  58#define PGDIR_MASK              (~(PGDIR_SIZE-1))
  59
  60/*
  61 * This is the lowest virtual address we can permit any user space
  62 * mapping to be mapped at.  This is particularly important for
  63 * non-high vector CPUs.
  64 */
  65#define FIRST_USER_ADDRESS      PAGE_SIZE
  66
  67#define FIRST_USER_PGD_NR       1
  68#define USER_PTRS_PER_PGD       ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
  69
  70/*
  71 * section address mask and size definitions.
  72 */
  73#define SECTION_SHIFT           22
  74#define SECTION_SIZE            (1UL << SECTION_SHIFT)
  75#define SECTION_MASK            (~(SECTION_SIZE-1))
  76
  77#ifndef __ASSEMBLY__
  78
  79/*
  80 * The pgprot_* and protection_map entries will be fixed up in runtime
  81 * to include the cachable bits based on memory policy, as well as any
  82 * architecture dependent bits.
  83 */
  84#define _PTE_DEFAULT            (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)
  85
  86extern pgprot_t pgprot_user;
  87extern pgprot_t pgprot_kernel;
  88
  89#define PAGE_NONE               pgprot_user
  90#define PAGE_SHARED             __pgprot(pgprot_val(pgprot_user | PTE_READ \
  91                                                                | PTE_WRITE))
  92#define PAGE_SHARED_EXEC        __pgprot(pgprot_val(pgprot_user | PTE_READ \
  93                                                                | PTE_WRITE \
  94                                                                | PTE_EXEC))
  95#define PAGE_COPY               __pgprot(pgprot_val(pgprot_user | PTE_READ)
  96#define PAGE_COPY_EXEC          __pgprot(pgprot_val(pgprot_user | PTE_READ \
  97                                                                | PTE_EXEC))
  98#define PAGE_READONLY           __pgprot(pgprot_val(pgprot_user | PTE_READ))
  99#define PAGE_READONLY_EXEC      __pgprot(pgprot_val(pgprot_user | PTE_READ \
 100                                                                | PTE_EXEC))
 101#define PAGE_KERNEL             pgprot_kernel
 102#define PAGE_KERNEL_EXEC        __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))
 103
 104#define __PAGE_NONE             __pgprot(_PTE_DEFAULT)
 105#define __PAGE_SHARED           __pgprot(_PTE_DEFAULT | PTE_READ \
 106                                                        | PTE_WRITE)
 107#define __PAGE_SHARED_EXEC      __pgprot(_PTE_DEFAULT | PTE_READ \
 108                                                        | PTE_WRITE \
 109                                                        | PTE_EXEC)
 110#define __PAGE_COPY             __pgprot(_PTE_DEFAULT | PTE_READ)
 111#define __PAGE_COPY_EXEC        __pgprot(_PTE_DEFAULT | PTE_READ \
 112                                                        | PTE_EXEC)
 113#define __PAGE_READONLY         __pgprot(_PTE_DEFAULT | PTE_READ)
 114#define __PAGE_READONLY_EXEC    __pgprot(_PTE_DEFAULT | PTE_READ \
 115                                                        | PTE_EXEC)
 116
 117#endif /* __ASSEMBLY__ */
 118
 119/*
 120 * The table below defines the page protection levels that we insert into our
 121 * Linux page table version.  These get translated into the best that the
 122 * architecture can perform.  Note that on UniCore hardware:
 123 *  1) We cannot do execute protection
 124 *  2) If we could do execute protection, then read is implied
 125 *  3) write implies read permissions
 126 */
 127#define __P000  __PAGE_NONE
 128#define __P001  __PAGE_READONLY
 129#define __P010  __PAGE_COPY
 130#define __P011  __PAGE_COPY
 131#define __P100  __PAGE_READONLY_EXEC
 132#define __P101  __PAGE_READONLY_EXEC
 133#define __P110  __PAGE_COPY_EXEC
 134#define __P111  __PAGE_COPY_EXEC
 135
 136#define __S000  __PAGE_NONE
 137#define __S001  __PAGE_READONLY
 138#define __S010  __PAGE_SHARED
 139#define __S011  __PAGE_SHARED
 140#define __S100  __PAGE_READONLY_EXEC
 141#define __S101  __PAGE_READONLY_EXEC
 142#define __S110  __PAGE_SHARED_EXEC
 143#define __S111  __PAGE_SHARED_EXEC
 144
 145#ifndef __ASSEMBLY__
 146/*
 147 * ZERO_PAGE is a global shared page that is always zero: used
 148 * for zero-mapped memory areas etc..
 149 */
 150extern struct page *empty_zero_page;
 151#define ZERO_PAGE(vaddr)                (empty_zero_page)
 152
 153#define pte_pfn(pte)                    (pte_val(pte) >> PAGE_SHIFT)
 154#define pfn_pte(pfn, prot)              (__pte(((pfn) << PAGE_SHIFT) \
 155                                                | pgprot_val(prot)))
 156
 157#define pte_none(pte)                   (!pte_val(pte))
 158#define pte_clear(mm, addr, ptep)       set_pte(ptep, __pte(0))
 159#define pte_page(pte)                   (pfn_to_page(pte_pfn(pte)))
 160#define pte_offset_kernel(dir, addr)    (pmd_page_vaddr(*(dir)) \
 161                                                + __pte_index(addr))
 162
 163#define pte_offset_map(dir, addr)       (pmd_page_vaddr(*(dir)) \
 164                                                + __pte_index(addr))
 165#define pte_unmap(pte)                  do { } while (0)
 166
 167#define set_pte(ptep, pte)      cpu_set_pte(ptep, pte)
 168
 169#define set_pte_at(mm, addr, ptep, pteval)      \
 170        do {                                    \
 171                set_pte(ptep, pteval);          \
 172        } while (0)
 173
 174/*
 175 * The following only work if pte_present() is true.
 176 * Undefined behaviour if not..
 177 */
 178#define pte_present(pte)        (pte_val(pte) & PTE_PRESENT)
 179#define pte_write(pte)          (pte_val(pte) & PTE_WRITE)
 180#define pte_dirty(pte)          (pte_val(pte) & PTE_DIRTY)
 181#define pte_young(pte)          (pte_val(pte) & PTE_YOUNG)
 182#define pte_exec(pte)           (pte_val(pte) & PTE_EXEC)
 183#define pte_special(pte)        (0)
 184
 185#define PTE_BIT_FUNC(fn, op) \
 186static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 187
 188PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
 189PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
 190PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
 191PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
 192PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
 193PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);
 194
 195static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 196
 197/*
 198 * Mark the prot value as uncacheable.
 199 */
 200#define pgprot_noncached(prot)          \
 201        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 202#define pgprot_writecombine(prot)       \
 203        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 204#define pgprot_dmacoherent(prot)        \
 205        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 206
 207#define pmd_none(pmd)           (!pmd_val(pmd))
 208#define pmd_present(pmd)        (pmd_val(pmd) & PMD_PRESENT)
 209#define pmd_bad(pmd)            (((pmd_val(pmd) &               \
 210                                (PMD_PRESENT | PMD_TYPE_MASK))  \
 211                                != (PMD_PRESENT | PMD_TYPE_TABLE)))
 212
 213#define set_pmd(pmdpd, pmdval)          \
 214        do {                            \
 215                *(pmdpd) = pmdval;      \
 216        } while (0)
 217
 218#define pmd_clear(pmdp)                 \
 219        do {                            \
 220                set_pmd(pmdp, __pmd(0));\
 221                clean_pmd_entry(pmdp);  \
 222        } while (0)
 223
 224#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
 225#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
 226
 227/*
 228 * Conversion functions: convert a page and protection to a page entry,
 229 * and a page entry and page directory to the page they refer to.
 230 */
 231#define mk_pte(page, prot)      pfn_pte(page_to_pfn(page), prot)
 232
 233/* to find an entry in a page-table-directory */
 234#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 235
 236#define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))
 237
 238/* to find an entry in a kernel page-table-directory */
 239#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 240
 241/* Find an entry in the third-level page table.. */
 242#define __pte_index(addr)       (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 243
 244static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 245{
 246        const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
 247        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 248        return pte;
 249}
 250
 251extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 252
 253/*
 254 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 255 * page tables as follows:
 256 *
 257 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 258 *   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
 259 *   <--------------- offset --------------> <--- type --> 0 0 0 0 0
 260 *
 261 * This gives us up to 127 swap files and 32GB per swap file.  Note that
 262 * the offset field is always non-zero.
 263 */
 264#define __SWP_TYPE_SHIFT        5
 265#define __SWP_TYPE_BITS         7
 266#define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 267#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 268
 269#define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT)          \
 270                                & __SWP_TYPE_MASK)
 271#define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 272#define __swp_entry(type, offset) ((swp_entry_t) {                      \
 273                                ((type) << __SWP_TYPE_SHIFT) |          \
 274                                ((offset) << __SWP_OFFSET_SHIFT) })
 275
 276#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 277#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 278
 279/*
 280 * It is an error for the kernel to have more swap files than we can
 281 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 282 * is increased beyond what we presently support.
 283 */
 284#define MAX_SWAPFILES_CHECK()   \
 285        BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 286
 287/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 288/* FIXME: this is not correct */
 289#define kern_addr_valid(addr)   (1)
 290
 291#include <asm-generic/pgtable.h>
 292
 293#define pgtable_cache_init() do { } while (0)
 294
 295#endif /* !__ASSEMBLY__ */
 296
 297#endif /* __UNICORE_PGTABLE_H__ */
 298