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

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * linux/arch/unicore32/include/asm/pgtable.h
   4 *
   5 * Code specific to PKUnity SoC and UniCore ISA
   6 *
   7 * Copyright (C) 2001-2010 GUAN Xue-tao
   8 */
   9#ifndef __UNICORE_PGTABLE_H__
  10#define __UNICORE_PGTABLE_H__
  11
  12#define __ARCH_USE_5LEVEL_HACK
  13#include <asm-generic/pgtable-nopmd.h>
  14#include <asm/cpu-single.h>
  15
  16#include <asm/memory.h>
  17#include <asm/pgtable-hwdef.h>
  18
  19/*
  20 * Just any arbitrary offset to the start of the vmalloc VM area: the
  21 * current 8MB value just means that there will be a 8MB "hole" after the
  22 * physical memory until the kernel virtual memory starts.  That means that
  23 * any out-of-bounds memory accesses will hopefully be caught.
  24 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  25 * area for the same reason. ;)
  26 *
  27 * Note that platforms may override VMALLOC_START, but they must provide
  28 * VMALLOC_END.  VMALLOC_END defines the (exclusive) limit of this space,
  29 * which may not overlap IO space.
  30 */
  31#ifndef VMALLOC_START
  32#define VMALLOC_OFFSET          SZ_8M
  33#define VMALLOC_START           (((unsigned long)high_memory + VMALLOC_OFFSET) \
  34                                        & ~(VMALLOC_OFFSET-1))
  35#define VMALLOC_END             (0xff000000UL)
  36#endif
  37
  38#define PTRS_PER_PTE            1024
  39#define PTRS_PER_PGD            1024
  40
  41/*
  42 * PGDIR_SHIFT determines what a third-level page table entry can map
  43 */
  44#define PGDIR_SHIFT             22
  45
  46#ifndef __ASSEMBLY__
  47extern void __pte_error(const char *file, int line, unsigned long val);
  48extern void __pgd_error(const char *file, int line, unsigned long val);
  49
  50#define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  51#define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
  52#endif /* !__ASSEMBLY__ */
  53
  54#define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  55#define PGDIR_MASK              (~(PGDIR_SIZE-1))
  56
  57/*
  58 * This is the lowest virtual address we can permit any user space
  59 * mapping to be mapped at.  This is particularly important for
  60 * non-high vector CPUs.
  61 */
  62#define FIRST_USER_ADDRESS      PAGE_SIZE
  63
  64#define FIRST_USER_PGD_NR       1
  65#define USER_PTRS_PER_PGD       ((TASK_SIZE/PGDIR_SIZE) - FIRST_USER_PGD_NR)
  66
  67/*
  68 * section address mask and size definitions.
  69 */
  70#define SECTION_SHIFT           22
  71#define SECTION_SIZE            (1UL << SECTION_SHIFT)
  72#define SECTION_MASK            (~(SECTION_SIZE-1))
  73
  74#ifndef __ASSEMBLY__
  75
  76/*
  77 * The pgprot_* and protection_map entries will be fixed up in runtime
  78 * to include the cachable bits based on memory policy, as well as any
  79 * architecture dependent bits.
  80 */
  81#define _PTE_DEFAULT            (PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE)
  82
  83extern pgprot_t pgprot_user;
  84extern pgprot_t pgprot_kernel;
  85
  86#define PAGE_NONE               pgprot_user
  87#define PAGE_SHARED             __pgprot(pgprot_val(pgprot_user | PTE_READ \
  88                                                                | PTE_WRITE))
  89#define PAGE_SHARED_EXEC        __pgprot(pgprot_val(pgprot_user | PTE_READ \
  90                                                                | PTE_WRITE \
  91                                                                | PTE_EXEC))
  92#define PAGE_COPY               __pgprot(pgprot_val(pgprot_user | PTE_READ)
  93#define PAGE_COPY_EXEC          __pgprot(pgprot_val(pgprot_user | PTE_READ \
  94                                                                | PTE_EXEC))
  95#define PAGE_READONLY           __pgprot(pgprot_val(pgprot_user | PTE_READ))
  96#define PAGE_READONLY_EXEC      __pgprot(pgprot_val(pgprot_user | PTE_READ \
  97                                                                | PTE_EXEC))
  98#define PAGE_KERNEL             pgprot_kernel
  99#define PAGE_KERNEL_EXEC        __pgprot(pgprot_val(pgprot_kernel | PTE_EXEC))
 100
 101#define __PAGE_NONE             __pgprot(_PTE_DEFAULT)
 102#define __PAGE_SHARED           __pgprot(_PTE_DEFAULT | PTE_READ \
 103                                                        | PTE_WRITE)
 104#define __PAGE_SHARED_EXEC      __pgprot(_PTE_DEFAULT | PTE_READ \
 105                                                        | PTE_WRITE \
 106                                                        | PTE_EXEC)
 107#define __PAGE_COPY             __pgprot(_PTE_DEFAULT | PTE_READ)
 108#define __PAGE_COPY_EXEC        __pgprot(_PTE_DEFAULT | PTE_READ \
 109                                                        | PTE_EXEC)
 110#define __PAGE_READONLY         __pgprot(_PTE_DEFAULT | PTE_READ)
 111#define __PAGE_READONLY_EXEC    __pgprot(_PTE_DEFAULT | PTE_READ \
 112                                                        | PTE_EXEC)
 113
 114#endif /* __ASSEMBLY__ */
 115
 116/*
 117 * The table below defines the page protection levels that we insert into our
 118 * Linux page table version.  These get translated into the best that the
 119 * architecture can perform.  Note that on UniCore hardware:
 120 *  1) We cannot do execute protection
 121 *  2) If we could do execute protection, then read is implied
 122 *  3) write implies read permissions
 123 */
 124#define __P000  __PAGE_NONE
 125#define __P001  __PAGE_READONLY
 126#define __P010  __PAGE_COPY
 127#define __P011  __PAGE_COPY
 128#define __P100  __PAGE_READONLY_EXEC
 129#define __P101  __PAGE_READONLY_EXEC
 130#define __P110  __PAGE_COPY_EXEC
 131#define __P111  __PAGE_COPY_EXEC
 132
 133#define __S000  __PAGE_NONE
 134#define __S001  __PAGE_READONLY
 135#define __S010  __PAGE_SHARED
 136#define __S011  __PAGE_SHARED
 137#define __S100  __PAGE_READONLY_EXEC
 138#define __S101  __PAGE_READONLY_EXEC
 139#define __S110  __PAGE_SHARED_EXEC
 140#define __S111  __PAGE_SHARED_EXEC
 141
 142#ifndef __ASSEMBLY__
 143/*
 144 * ZERO_PAGE is a global shared page that is always zero: used
 145 * for zero-mapped memory areas etc..
 146 */
 147extern struct page *empty_zero_page;
 148#define ZERO_PAGE(vaddr)                (empty_zero_page)
 149
 150#define pte_pfn(pte)                    (pte_val(pte) >> PAGE_SHIFT)
 151#define pfn_pte(pfn, prot)              (__pte(((pfn) << PAGE_SHIFT) \
 152                                                | pgprot_val(prot)))
 153
 154#define pte_none(pte)                   (!pte_val(pte))
 155#define pte_clear(mm, addr, ptep)       set_pte(ptep, __pte(0))
 156#define pte_page(pte)                   (pfn_to_page(pte_pfn(pte)))
 157#define pte_offset_kernel(dir, addr)    (pmd_page_vaddr(*(dir)) \
 158                                                + __pte_index(addr))
 159
 160#define pte_offset_map(dir, addr)       (pmd_page_vaddr(*(dir)) \
 161                                                + __pte_index(addr))
 162#define pte_unmap(pte)                  do { } while (0)
 163
 164#define set_pte(ptep, pte)      cpu_set_pte(ptep, pte)
 165
 166#define set_pte_at(mm, addr, ptep, pteval)      \
 167        do {                                    \
 168                set_pte(ptep, pteval);          \
 169        } while (0)
 170
 171/*
 172 * The following only work if pte_present() is true.
 173 * Undefined behaviour if not..
 174 */
 175#define pte_present(pte)        (pte_val(pte) & PTE_PRESENT)
 176#define pte_write(pte)          (pte_val(pte) & PTE_WRITE)
 177#define pte_dirty(pte)          (pte_val(pte) & PTE_DIRTY)
 178#define pte_young(pte)          (pte_val(pte) & PTE_YOUNG)
 179#define pte_exec(pte)           (pte_val(pte) & PTE_EXEC)
 180#define pte_special(pte)        (0)
 181
 182#define PTE_BIT_FUNC(fn, op) \
 183static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
 184
 185PTE_BIT_FUNC(wrprotect, &= ~PTE_WRITE);
 186PTE_BIT_FUNC(mkwrite,   |= PTE_WRITE);
 187PTE_BIT_FUNC(mkclean,   &= ~PTE_DIRTY);
 188PTE_BIT_FUNC(mkdirty,   |= PTE_DIRTY);
 189PTE_BIT_FUNC(mkold,     &= ~PTE_YOUNG);
 190PTE_BIT_FUNC(mkyoung,   |= PTE_YOUNG);
 191
 192static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 193
 194/*
 195 * Mark the prot value as uncacheable.
 196 */
 197#define pgprot_noncached(prot)          \
 198        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 199#define pgprot_writecombine(prot)       \
 200        __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE)
 201
 202#define pmd_none(pmd)           (!pmd_val(pmd))
 203#define pmd_present(pmd)        (pmd_val(pmd) & PMD_PRESENT)
 204#define pmd_bad(pmd)            (((pmd_val(pmd) &               \
 205                                (PMD_PRESENT | PMD_TYPE_MASK))  \
 206                                != (PMD_PRESENT | PMD_TYPE_TABLE)))
 207
 208#define set_pmd(pmdpd, pmdval)          \
 209        do {                            \
 210                *(pmdpd) = pmdval;      \
 211        } while (0)
 212
 213#define pmd_clear(pmdp)                 \
 214        do {                            \
 215                set_pmd(pmdp, __pmd(0));\
 216                clean_pmd_entry(pmdp);  \
 217        } while (0)
 218
 219#define pmd_page_vaddr(pmd) ((pte_t *)__va(pmd_val(pmd) & PAGE_MASK))
 220#define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
 221
 222/*
 223 * Conversion functions: convert a page and protection to a page entry,
 224 * and a page entry and page directory to the page they refer to.
 225 */
 226#define mk_pte(page, prot)      pfn_pte(page_to_pfn(page), prot)
 227
 228/* to find an entry in a page-table-directory */
 229#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 230
 231#define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))
 232
 233/* to find an entry in a kernel page-table-directory */
 234#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 235
 236/* Find an entry in the third-level page table.. */
 237#define __pte_index(addr)       (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 238
 239static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 240{
 241        const unsigned long mask = PTE_EXEC | PTE_WRITE | PTE_READ;
 242        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 243        return pte;
 244}
 245
 246extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 247
 248/*
 249 * Encode and decode a swap entry.  Swap entries are stored in the Linux
 250 * page tables as follows:
 251 *
 252 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 253 *   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
 254 *   <--------------- offset --------------> <--- type --> 0 0 0 0 0
 255 *
 256 * This gives us up to 127 swap files and 32GB per swap file.  Note that
 257 * the offset field is always non-zero.
 258 */
 259#define __SWP_TYPE_SHIFT        5
 260#define __SWP_TYPE_BITS         7
 261#define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 262#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 263
 264#define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT)          \
 265                                & __SWP_TYPE_MASK)
 266#define __swp_offset(x)         ((x).val >> __SWP_OFFSET_SHIFT)
 267#define __swp_entry(type, offset) ((swp_entry_t) {                      \
 268                                ((type) << __SWP_TYPE_SHIFT) |          \
 269                                ((offset) << __SWP_OFFSET_SHIFT) })
 270
 271#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 272#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 273
 274/*
 275 * It is an error for the kernel to have more swap files than we can
 276 * encode in the PTEs.  This ensures that we know when MAX_SWAPFILES
 277 * is increased beyond what we presently support.
 278 */
 279#define MAX_SWAPFILES_CHECK()   \
 280        BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 281
 282/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 283/* FIXME: this is not correct */
 284#define kern_addr_valid(addr)   (1)
 285
 286#include <asm-generic/pgtable.h>
 287
 288#endif /* !__ASSEMBLY__ */
 289
 290#endif /* __UNICORE_PGTABLE_H__ */
 291