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__
  49 extern void __pte_error(const char *file, int line, unsigned long val);
  50 extern 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
  85 extern pgprot_t pgprot_user;
  86 extern 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  */
 149 extern 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) \
 185 static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 186
 187 PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
 188 PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
 189 PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
 190 PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
 191 PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
 192 PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);
 193
 194 static 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
 243 static 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
 250 extern 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 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 287 /* FIXME: this is not correct */
 288 #define kern_addr_valid(addr)   (1)
 289
 290 #include <asm-generic/pgtable.h>
 291
 292 #define pgtable_cache_init() do { } while (0)
 293
 294 #endif /* !__ASSEMBLY__ */
 295
 296 #endif /* __UNICORE_PGTABLE_H__ */