arch/tile/include/asm/pgtable.h

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  *
  14  * This file contains the functions and defines necessary to modify and use
  15  * the TILE page table tree.
  16  */
  17
  18 #ifndef _ASM_TILE_PGTABLE_H
  19 #define _ASM_TILE_PGTABLE_H
  20
  21 #include <hv/hypervisor.h>
  22
  23 #ifndef __ASSEMBLY__
  24
  25 #include <linux/bitops.h>
  26 #include <linux/threads.h>
  27 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/spinlock.h>
  30 #include <asm/processor.h>
  31 #include <asm/fixmap.h>
  32
  33 struct mm_struct;
  34 struct vm_area_struct;
  35
  36 /*
  37  * ZERO_PAGE is a global shared page that is always zero: used
  38  * for zero-mapped memory areas etc..
  39  */
  40 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
  41 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  42
  43 extern pgd_t swapper_pg_dir[];
  44 extern pgprot_t swapper_pgprot;
  45 extern struct kmem_cache *pgd_cache;
  46 extern spinlock_t pgd_lock;
  47 extern struct list_head pgd_list;
  48
  49 /*
  50  * The very last slots in the pgd_t are for addresses unusable by Linux
  51  * (pgd_addr_invalid() returns true).  So we use them for the list structure.
  52  * The x86 code we are modelled on uses the page->private/index fields
  53  * (older 2.6 kernels) or the lru list (newer 2.6 kernels), but since
  54  * our pgds are so much smaller than a page, it seems a waste to
  55  * spend a whole page on each pgd.
  56  */
  57 #define PGD_LIST_OFFSET \
  58   ((PTRS_PER_PGD * sizeof(pgd_t)) - sizeof(struct list_head))
  59 #define pgd_to_list(pgd) \
  60   ((struct list_head *)((char *)(pgd) + PGD_LIST_OFFSET))
  61 #define list_to_pgd(list) \
  62   ((pgd_t *)((char *)(list) - PGD_LIST_OFFSET))
  63
  64 extern void pgtable_cache_init(void);
  65 extern void paging_init(void);
  66 extern void set_page_homes(void);
  67
  68 #define FIRST_USER_ADDRESS      0
  69
  70 #define _PAGE_PRESENT           HV_PTE_PRESENT
  71 #define _PAGE_HUGE_PAGE         HV_PTE_PAGE
  72 #define _PAGE_READABLE          HV_PTE_READABLE
  73 #define _PAGE_WRITABLE          HV_PTE_WRITABLE
  74 #define _PAGE_EXECUTABLE        HV_PTE_EXECUTABLE
  75 #define _PAGE_ACCESSED          HV_PTE_ACCESSED
  76 #define _PAGE_DIRTY             HV_PTE_DIRTY
  77 #define _PAGE_GLOBAL            HV_PTE_GLOBAL
  78 #define _PAGE_USER              HV_PTE_USER
  79
  80 /*
  81  * All the "standard" bits.  Cache-control bits are managed elsewhere.
  82  * This is used to test for valid level-2 page table pointers by checking
  83  * all the bits, and to mask away the cache control bits for mprotect.
  84  */
  85 #define _PAGE_ALL (\
  86   _PAGE_PRESENT | \
  87   _PAGE_HUGE_PAGE | \
  88   _PAGE_READABLE | \
  89   _PAGE_WRITABLE | \
  90   _PAGE_EXECUTABLE | \
  91   _PAGE_ACCESSED | \
  92   _PAGE_DIRTY | \
  93   _PAGE_GLOBAL | \
  94   _PAGE_USER \
  95 )
  96
  97 #define PAGE_NONE \
  98         __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
  99 #define PAGE_SHARED \
 100         __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
 101                  _PAGE_USER | _PAGE_ACCESSED)
 102
 103 #define PAGE_SHARED_EXEC \
 104         __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
 105                  _PAGE_EXECUTABLE | _PAGE_USER | _PAGE_ACCESSED)
 106 #define PAGE_COPY_NOEXEC \
 107         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
 108 #define PAGE_COPY_EXEC \
 109         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
 110                  _PAGE_READABLE | _PAGE_EXECUTABLE)
 111 #define PAGE_COPY \
 112         PAGE_COPY_NOEXEC
 113 #define PAGE_READONLY \
 114         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
 115 #define PAGE_READONLY_EXEC \
 116         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
 117                  _PAGE_READABLE | _PAGE_EXECUTABLE)
 118
 119 #define _PAGE_KERNEL_RO \
 120  (_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_READABLE | _PAGE_ACCESSED)
 121 #define _PAGE_KERNEL \
 122  (_PAGE_KERNEL_RO | _PAGE_WRITABLE | _PAGE_DIRTY)
 123 #define _PAGE_KERNEL_EXEC       (_PAGE_KERNEL_RO | _PAGE_EXECUTABLE)
 124
 125 #define PAGE_KERNEL             __pgprot(_PAGE_KERNEL)
 126 #define PAGE_KERNEL_RO          __pgprot(_PAGE_KERNEL_RO)
 127 #define PAGE_KERNEL_EXEC        __pgprot(_PAGE_KERNEL_EXEC)
 128
 129 #define page_to_kpgprot(p) PAGE_KERNEL
 130
 131 /*
 132  * We could tighten these up, but for now writable or executable
 133  * implies readable.
 134  */
 135 #define __P000  PAGE_NONE
 136 #define __P001  PAGE_READONLY
 137 #define __P010  PAGE_COPY      /* this is write-only, which we won't support */
 138 #define __P011  PAGE_COPY
 139 #define __P100  PAGE_READONLY_EXEC
 140 #define __P101  PAGE_READONLY_EXEC
 141 #define __P110  PAGE_COPY_EXEC
 142 #define __P111  PAGE_COPY_EXEC
 143
 144 #define __S000  PAGE_NONE
 145 #define __S001  PAGE_READONLY
 146 #define __S010  PAGE_SHARED
 147 #define __S011  PAGE_SHARED
 148 #define __S100  PAGE_READONLY_EXEC
 149 #define __S101  PAGE_READONLY_EXEC
 150 #define __S110  PAGE_SHARED_EXEC
 151 #define __S111  PAGE_SHARED_EXEC
 152
 153 /*
 154  * All the normal _PAGE_ALL bits are ignored for PMDs, except PAGE_PRESENT
 155  * and PAGE_HUGE_PAGE, which must be one and zero, respectively.
 156  * We set the ignored bits to zero.
 157  */
 158 #define _PAGE_TABLE     _PAGE_PRESENT
 159
 160 /* Inherit the caching flags from the old protection bits. */
 161 #define pgprot_modify(oldprot, newprot) \
 162   (pgprot_t) { ((oldprot).val & ~_PAGE_ALL) | (newprot).val }
 163
 164 /* Just setting the PFN to zero suffices. */
 165 #define pte_pgprot(x) hv_pte_set_pfn((x), 0)
 166
 167 /*
 168  * For PTEs and PDEs, we must clear the Present bit first when
 169  * clearing a page table entry, so clear the bottom half first and
 170  * enforce ordering with a barrier.
 171  */
 172 static inline void __pte_clear(pte_t *ptep)
 173 {
 174 #ifdef __tilegx__
 175         ptep->val = 0;
 176 #else
 177         u32 *tmp = (u32 *)ptep;
 178         tmp[0] = 0;
 179         barrier();
 180         tmp[1] = 0;
 181 #endif
 182 }
 183 #define pte_clear(mm, addr, ptep) __pte_clear(ptep)
 184
 185 /*
 186  * The following only work if pte_present() is true.
 187  * Undefined behaviour if not..
 188  */
 189 #define pte_present hv_pte_get_present
 190 #define pte_user hv_pte_get_user
 191 #define pte_read hv_pte_get_readable
 192 #define pte_dirty hv_pte_get_dirty
 193 #define pte_young hv_pte_get_accessed
 194 #define pte_write hv_pte_get_writable
 195 #define pte_exec hv_pte_get_executable
 196 #define pte_huge hv_pte_get_page
 197 #define pte_rdprotect hv_pte_clear_readable
 198 #define pte_exprotect hv_pte_clear_executable
 199 #define pte_mkclean hv_pte_clear_dirty
 200 #define pte_mkold hv_pte_clear_accessed
 201 #define pte_wrprotect hv_pte_clear_writable
 202 #define pte_mksmall hv_pte_clear_page
 203 #define pte_mkread hv_pte_set_readable
 204 #define pte_mkexec hv_pte_set_executable
 205 #define pte_mkdirty hv_pte_set_dirty
 206 #define pte_mkyoung hv_pte_set_accessed
 207 #define pte_mkwrite hv_pte_set_writable
 208 #define pte_mkhuge hv_pte_set_page
 209
 210 #define pte_special(pte) 0
 211 #define pte_mkspecial(pte) (pte)
 212
 213 /*
 214  * Use some spare bits in the PTE for user-caching tags.
 215  */
 216 #define pte_set_forcecache hv_pte_set_client0
 217 #define pte_get_forcecache hv_pte_get_client0
 218 #define pte_clear_forcecache hv_pte_clear_client0
 219 #define pte_set_anyhome hv_pte_set_client1
 220 #define pte_get_anyhome hv_pte_get_client1
 221 #define pte_clear_anyhome hv_pte_clear_client1
 222
 223 /*
 224  * A migrating PTE has PAGE_PRESENT clear but all the other bits preserved.
 225  */
 226 #define pte_migrating hv_pte_get_migrating
 227 #define pte_mkmigrate(x) hv_pte_set_migrating(hv_pte_clear_present(x))
 228 #define pte_donemigrate(x) hv_pte_set_present(hv_pte_clear_migrating(x))
 229
 230 #define pte_ERROR(e) \
 231         pr_err("%s:%d: bad pte 0x%016llx.\n", __FILE__, __LINE__, pte_val(e))
 232 #define pgd_ERROR(e) \
 233         pr_err("%s:%d: bad pgd 0x%016llx.\n", __FILE__, __LINE__, pgd_val(e))
 234
 235 /* Return PA and protection info for a given kernel VA. */
 236 int va_to_cpa_and_pte(void *va, phys_addr_t *cpa, pte_t *pte);
 237
 238 /*
 239  * __set_pte() ensures we write the 64-bit PTE with 32-bit words in
 240  * the right order on 32-bit platforms and also allows us to write
 241  * hooks to check valid PTEs, etc., if we want.
 242  */
 243 void __set_pte(pte_t *ptep, pte_t pte);
 244
 245 /*
 246  * set_pte() sets the given PTE and also sanity-checks the
 247  * requested PTE against the page homecaching.  Unspecified parts
 248  * of the PTE are filled in when it is written to memory, i.e. all
 249  * caching attributes if "!forcecache", or the home cpu if "anyhome".
 250  */
 251 extern void set_pte(pte_t *ptep, pte_t pte);
 252 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
 253 #define set_pte_atomic(pteptr, pteval) set_pte(pteptr, pteval)
 254
 255 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 256
 257 static inline int pte_none(pte_t pte)
 258 {
 259         return !pte.val;
 260 }
 261
 262 static inline unsigned long pte_pfn(pte_t pte)
 263 {
 264         return hv_pte_get_pfn(pte);
 265 }
 266
 267 /* Set or get the remote cache cpu in a pgprot with remote caching. */
 268 extern pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu);
 269 extern int get_remote_cache_cpu(pgprot_t prot);
 270
 271 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 272 {
 273         return hv_pte_set_pfn(prot, pfn);
 274 }
 275
 276 /* Support for priority mappings. */
 277 extern void start_mm_caching(struct mm_struct *mm);
 278 extern void check_mm_caching(struct mm_struct *prev, struct mm_struct *next);
 279
 280 /*
 281  * Support non-linear file mappings (see sys_remap_file_pages).
 282  * This is defined by CLIENT1 set but CLIENT0 and _PAGE_PRESENT clear, and the
 283  * file offset in the 32 high bits.
 284  */
 285 #define _PAGE_FILE        HV_PTE_CLIENT1
 286 #define PTE_FILE_MAX_BITS 32
 287 #define pte_file(pte)     (hv_pte_get_client1(pte) && !hv_pte_get_client0(pte))
 288 #define pte_to_pgoff(pte) ((pte).val >> 32)
 289 #define pgoff_to_pte(off) ((pte_t) { (((long long)(off)) << 32) | _PAGE_FILE })
 290
 291 /*
 292  * Encode and de-code a swap entry (see <linux/swapops.h>).
 293  * We put the swap file type+offset in the 32 high bits;
 294  * I believe we can just leave the low bits clear.
 295  */
 296 #define __swp_type(swp)         ((swp).val & 0x1f)
 297 #define __swp_offset(swp)       ((swp).val >> 5)
 298 #define __swp_entry(type, off)  ((swp_entry_t) { (type) | ((off) << 5) })
 299 #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).val >> 32 })
 300 #define __swp_entry_to_pte(swp) ((pte_t) { (((long long) ((swp).val)) << 32) })
 301
 302 /*
 303  * Conversion functions: convert a page and protection to a page entry,
 304  * and a page entry and page directory to the page they refer to.
 305  */
 306
 307 #define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 308
 309 /*
 310  * If we are doing an mprotect(), just accept the new vma->vm_page_prot
 311  * value and combine it with the PFN from the old PTE to get a new PTE.
 312  */
 313 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 314 {
 315         return pfn_pte(hv_pte_get_pfn(pte), newprot);
 316 }
 317
 318 /*
 319  * The pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 320  *
 321  * This macro returns the index of the entry in the pgd page which would
 322  * control the given virtual address.
 323  */
 324 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 325
 326 /*
 327  * pgd_offset() returns a (pgd_t *)
 328  * pgd_index() is used get the offset into the pgd page's array of pgd_t's.
 329  */
 330 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
 331
 332 /*
 333  * A shortcut which implies the use of the kernel's pgd, instead
 334  * of a process's.
 335  */
 336 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 337
 338 #if defined(CONFIG_HIGHPTE)
 339 extern pte_t *pte_offset_map(pmd_t *, unsigned long address);
 340 #define pte_unmap(pte) kunmap_atomic(pte)
 341 #else
 342 #define pte_offset_map(dir, address) pte_offset_kernel(dir, address)
 343 #define pte_unmap(pte) do { } while (0)
 344 #endif
 345
 346 /* Clear a non-executable kernel PTE and flush it from the TLB. */
 347 #define kpte_clear_flush(ptep, vaddr)           \
 348 do {                                            \
 349         pte_clear(&init_mm, (vaddr), (ptep));   \
 350         local_flush_tlb_page(FLUSH_NONEXEC, (vaddr), PAGE_SIZE); \
 351 } while (0)
 352
 353 /*
 354  * The kernel page tables contain what we need, and we flush when we
 355  * change specific page table entries.
 356  */
 357 #define update_mmu_cache(vma, address, pte) do { } while (0)
 358
 359 #ifdef CONFIG_FLATMEM
 360 #define kern_addr_valid(addr)   (1)
 361 #endif /* CONFIG_FLATMEM */
 362
 363 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
 364                 remap_pfn_range(vma, vaddr, pfn, size, prot)
 365
 366 extern void vmalloc_sync_all(void);
 367
 368 #endif /* !__ASSEMBLY__ */
 369
 370 #ifdef __tilegx__
 371 #include <asm/pgtable_64.h>
 372 #else
 373 #include <asm/pgtable_32.h>
 374 #endif
 375
 376 #ifndef __ASSEMBLY__
 377
 378 static inline int pmd_none(pmd_t pmd)
 379 {
 380         /*
 381          * Only check low word on 32-bit platforms, since it might be
 382          * out of sync with upper half.
 383          */
 384         return (unsigned long)pmd_val(pmd) == 0;
 385 }
 386
 387 static inline int pmd_present(pmd_t pmd)
 388 {
 389         return pmd_val(pmd) & _PAGE_PRESENT;
 390 }
 391
 392 static inline int pmd_bad(pmd_t pmd)
 393 {
 394         return ((pmd_val(pmd) & _PAGE_ALL) != _PAGE_TABLE);
 395 }
 396
 397 static inline unsigned long pages_to_mb(unsigned long npg)
 398 {
 399         return npg >> (20 - PAGE_SHIFT);
 400 }
 401
 402 /*
 403  * The pmd can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 404  *
 405  * This function returns the index of the entry in the pmd which would
 406  * control the given virtual address.
 407  */
 408 static inline unsigned long pmd_index(unsigned long address)
 409 {
 410         return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
 411 }
 412
 413 /*
 414  * A given kernel pmd_t maps to a specific virtual address (either a
 415  * kernel huge page or a kernel pte_t table).  Since kernel pte_t
 416  * tables can be aligned at sub-page granularity, this function can
 417  * return non-page-aligned pointers, despite its name.
 418  */
 419 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 420 {
 421         phys_addr_t pa =
 422                 (phys_addr_t)pmd_ptfn(pmd) << HV_LOG2_PAGE_TABLE_ALIGN;
 423         return (unsigned long)__va(pa);
 424 }
 425
 426 /*
 427  * A pmd_t points to the base of a huge page or to a pte_t array.
 428  * If a pte_t array, since we can have multiple per page, we don't
 429  * have a one-to-one mapping of pmd_t's to pages.  However, this is
 430  * OK for pte_lockptr(), since we just end up with potentially one
 431  * lock being used for several pte_t arrays.
 432  */
 433 #define pmd_page(pmd) pfn_to_page(HV_PTFN_TO_PFN(pmd_ptfn(pmd)))
 434
 435 /*
 436  * The pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 437  *
 438  * This macro returns the index of the entry in the pte page which would
 439  * control the given virtual address.
 440  */
 441 static inline unsigned long pte_index(unsigned long address)
 442 {
 443         return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
 444 }
 445
 446 static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
 447 {
 448        return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
 449 }
 450
 451 static inline int pmd_huge_page(pmd_t pmd)
 452 {
 453         return pmd_val(pmd) & _PAGE_HUGE_PAGE;
 454 }
 455
 456 #include <asm-generic/pgtable.h>
 457
 458 /* Support /proc/NN/pgtable API. */
 459 struct seq_file;
 460 int arch_proc_pgtable_show(struct seq_file *m, struct mm_struct *mm,
 461                            unsigned long vaddr, pte_t *ptep, void **datap);
 462
 463 #endif /* !__ASSEMBLY__ */
 464
 465 #endif /* _ASM_TILE_PGTABLE_H */