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 <linux/pfn.h>
  31 #include <asm/processor.h>
  32 #include <asm/fixmap.h>
  33 #include <asm/page.h>
  34
  35 struct mm_struct;
  36 struct vm_area_struct;
  37
  38 /*
  39  * ZERO_PAGE is a global shared page that is always zero: used
  40  * for zero-mapped memory areas etc..
  41  */
  42 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
  43 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  44
  45 extern pgd_t swapper_pg_dir[];
  46 extern pgprot_t swapper_pgprot;
  47 extern struct kmem_cache *pgd_cache;
  48 extern spinlock_t pgd_lock;
  49 extern struct list_head pgd_list;
  50
  51 /*
  52  * The very last slots in the pgd_t are for addresses unusable by Linux
  53  * (pgd_addr_invalid() returns true).  So we use them for the list structure.
  54  * The x86 code we are modelled on uses the page->private/index fields
  55  * (older 2.6 kernels) or the lru list (newer 2.6 kernels), but since
  56  * our pgds are so much smaller than a page, it seems a waste to
  57  * spend a whole page on each pgd.
  58  */
  59 #define PGD_LIST_OFFSET \
  60   ((PTRS_PER_PGD * sizeof(pgd_t)) - sizeof(struct list_head))
  61 #define pgd_to_list(pgd) \
  62   ((struct list_head *)((char *)(pgd) + PGD_LIST_OFFSET))
  63 #define list_to_pgd(list) \
  64   ((pgd_t *)((char *)(list) - PGD_LIST_OFFSET))
  65
  66 extern void pgtable_cache_init(void);
  67 extern void paging_init(void);
  68 extern void set_page_homes(void);
  69
  70 #define FIRST_USER_ADDRESS      0UL
  71
  72 #define _PAGE_PRESENT           HV_PTE_PRESENT
  73 #define _PAGE_HUGE_PAGE         HV_PTE_PAGE
  74 #define _PAGE_SUPER_PAGE        HV_PTE_SUPER
  75 #define _PAGE_READABLE          HV_PTE_READABLE
  76 #define _PAGE_WRITABLE          HV_PTE_WRITABLE
  77 #define _PAGE_EXECUTABLE        HV_PTE_EXECUTABLE
  78 #define _PAGE_ACCESSED          HV_PTE_ACCESSED
  79 #define _PAGE_DIRTY             HV_PTE_DIRTY
  80 #define _PAGE_GLOBAL            HV_PTE_GLOBAL
  81 #define _PAGE_USER              HV_PTE_USER
  82
  83 /*
  84  * All the "standard" bits.  Cache-control bits are managed elsewhere.
  85  * This is used to test for valid level-2 page table pointers by checking
  86  * all the bits, and to mask away the cache control bits for mprotect.
  87  */
  88 #define _PAGE_ALL (\
  89   _PAGE_PRESENT | \
  90   _PAGE_HUGE_PAGE | \
  91   _PAGE_SUPER_PAGE | \
  92   _PAGE_READABLE | \
  93   _PAGE_WRITABLE | \
  94   _PAGE_EXECUTABLE | \
  95   _PAGE_ACCESSED | \
  96   _PAGE_DIRTY | \
  97   _PAGE_GLOBAL | \
  98   _PAGE_USER \
  99 )
 100
 101 #define PAGE_NONE \
 102         __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
 103 #define PAGE_SHARED \
 104         __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
 105                  _PAGE_USER | _PAGE_ACCESSED)
 106
 107 #define PAGE_SHARED_EXEC \
 108         __pgprot(_PAGE_PRESENT | _PAGE_READABLE | _PAGE_WRITABLE | \
 109                  _PAGE_EXECUTABLE | _PAGE_USER | _PAGE_ACCESSED)
 110 #define PAGE_COPY_NOEXEC \
 111         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
 112 #define PAGE_COPY_EXEC \
 113         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
 114                  _PAGE_READABLE | _PAGE_EXECUTABLE)
 115 #define PAGE_COPY \
 116         PAGE_COPY_NOEXEC
 117 #define PAGE_READONLY \
 118         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_READABLE)
 119 #define PAGE_READONLY_EXEC \
 120         __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | \
 121                  _PAGE_READABLE | _PAGE_EXECUTABLE)
 122
 123 #define _PAGE_KERNEL_RO \
 124  (_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_READABLE | _PAGE_ACCESSED)
 125 #define _PAGE_KERNEL \
 126  (_PAGE_KERNEL_RO | _PAGE_WRITABLE | _PAGE_DIRTY)
 127 #define _PAGE_KERNEL_EXEC       (_PAGE_KERNEL_RO | _PAGE_EXECUTABLE)
 128
 129 #define PAGE_KERNEL             __pgprot(_PAGE_KERNEL)
 130 #define PAGE_KERNEL_RO          __pgprot(_PAGE_KERNEL_RO)
 131 #define PAGE_KERNEL_EXEC        __pgprot(_PAGE_KERNEL_EXEC)
 132
 133 #define page_to_kpgprot(p) PAGE_KERNEL
 134
 135 /*
 136  * We could tighten these up, but for now writable or executable
 137  * implies readable.
 138  */
 139 #define __P000  PAGE_NONE
 140 #define __P001  PAGE_READONLY
 141 #define __P010  PAGE_COPY      /* this is write-only, which we won't support */
 142 #define __P011  PAGE_COPY
 143 #define __P100  PAGE_READONLY_EXEC
 144 #define __P101  PAGE_READONLY_EXEC
 145 #define __P110  PAGE_COPY_EXEC
 146 #define __P111  PAGE_COPY_EXEC
 147
 148 #define __S000  PAGE_NONE
 149 #define __S001  PAGE_READONLY
 150 #define __S010  PAGE_SHARED
 151 #define __S011  PAGE_SHARED
 152 #define __S100  PAGE_READONLY_EXEC
 153 #define __S101  PAGE_READONLY_EXEC
 154 #define __S110  PAGE_SHARED_EXEC
 155 #define __S111  PAGE_SHARED_EXEC
 156
 157 /*
 158  * All the normal _PAGE_ALL bits are ignored for PMDs, except PAGE_PRESENT
 159  * and PAGE_HUGE_PAGE, which must be one and zero, respectively.
 160  * We set the ignored bits to zero.
 161  */
 162 #define _PAGE_TABLE     _PAGE_PRESENT
 163
 164 /* Inherit the caching flags from the old protection bits. */
 165 #define pgprot_modify(oldprot, newprot) \
 166   (pgprot_t) { ((oldprot).val & ~_PAGE_ALL) | (newprot).val }
 167
 168 /* Just setting the PFN to zero suffices. */
 169 #define pte_pgprot(x) hv_pte_set_pa((x), 0)
 170
 171 /*
 172  * For PTEs and PDEs, we must clear the Present bit first when
 173  * clearing a page table entry, so clear the bottom half first and
 174  * enforce ordering with a barrier.
 175  */
 176 static inline void __pte_clear(pte_t *ptep)
 177 {
 178 #ifdef __tilegx__
 179         ptep->val = 0;
 180 #else
 181         u32 *tmp = (u32 *)ptep;
 182         tmp[0] = 0;
 183         barrier();
 184         tmp[1] = 0;
 185 #endif
 186 }
 187 #define pte_clear(mm, addr, ptep) __pte_clear(ptep)
 188
 189 /*
 190  * The following only work if pte_present() is true.
 191  * Undefined behaviour if not..
 192  */
 193 #define pte_present hv_pte_get_present
 194 #define pte_mknotpresent hv_pte_clear_present
 195 #define pte_user hv_pte_get_user
 196 #define pte_read hv_pte_get_readable
 197 #define pte_dirty hv_pte_get_dirty
 198 #define pte_young hv_pte_get_accessed
 199 #define pte_write hv_pte_get_writable
 200 #define pte_exec hv_pte_get_executable
 201 #define pte_huge hv_pte_get_page
 202 #define pte_super hv_pte_get_super
 203 #define pte_rdprotect hv_pte_clear_readable
 204 #define pte_exprotect hv_pte_clear_executable
 205 #define pte_mkclean hv_pte_clear_dirty
 206 #define pte_mkold hv_pte_clear_accessed
 207 #define pte_wrprotect hv_pte_clear_writable
 208 #define pte_mksmall hv_pte_clear_page
 209 #define pte_mkread hv_pte_set_readable
 210 #define pte_mkexec hv_pte_set_executable
 211 #define pte_mkdirty hv_pte_set_dirty
 212 #define pte_mkyoung hv_pte_set_accessed
 213 #define pte_mkwrite hv_pte_set_writable
 214 #define pte_mkhuge hv_pte_set_page
 215 #define pte_mksuper hv_pte_set_super
 216
 217 #define pte_special(pte) 0
 218 #define pte_mkspecial(pte) (pte)
 219
 220 /*
 221  * Use some spare bits in the PTE for user-caching tags.
 222  */
 223 #define pte_set_forcecache hv_pte_set_client0
 224 #define pte_get_forcecache hv_pte_get_client0
 225 #define pte_clear_forcecache hv_pte_clear_client0
 226 #define pte_set_anyhome hv_pte_set_client1
 227 #define pte_get_anyhome hv_pte_get_client1
 228 #define pte_clear_anyhome hv_pte_clear_client1
 229
 230 /*
 231  * A migrating PTE has PAGE_PRESENT clear but all the other bits preserved.
 232  */
 233 #define pte_migrating hv_pte_get_migrating
 234 #define pte_mkmigrate(x) hv_pte_set_migrating(hv_pte_clear_present(x))
 235 #define pte_donemigrate(x) hv_pte_set_present(hv_pte_clear_migrating(x))
 236
 237 #define pte_ERROR(e) \
 238         pr_err("%s:%d: bad pte 0x%016llx\n", __FILE__, __LINE__, pte_val(e))
 239 #define pgd_ERROR(e) \
 240         pr_err("%s:%d: bad pgd 0x%016llx\n", __FILE__, __LINE__, pgd_val(e))
 241
 242 /* Return PA and protection info for a given kernel VA. */
 243 int va_to_cpa_and_pte(void *va, phys_addr_t *cpa, pte_t *pte);
 244
 245 /*
 246  * __set_pte() ensures we write the 64-bit PTE with 32-bit words in
 247  * the right order on 32-bit platforms and also allows us to write
 248  * hooks to check valid PTEs, etc., if we want.
 249  */
 250 void __set_pte(pte_t *ptep, pte_t pte);
 251
 252 /*
 253  * set_pte() sets the given PTE and also sanity-checks the
 254  * requested PTE against the page homecaching.  Unspecified parts
 255  * of the PTE are filled in when it is written to memory, i.e. all
 256  * caching attributes if "!forcecache", or the home cpu if "anyhome".
 257  */
 258 extern void set_pte(pte_t *ptep, pte_t pte);
 259 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
 260 #define set_pte_atomic(pteptr, pteval) set_pte(pteptr, pteval)
 261
 262 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 263
 264 static inline int pte_none(pte_t pte)
 265 {
 266         return !pte.val;
 267 }
 268
 269 static inline unsigned long pte_pfn(pte_t pte)
 270 {
 271         return PFN_DOWN(hv_pte_get_pa(pte));
 272 }
 273
 274 /* Set or get the remote cache cpu in a pgprot with remote caching. */
 275 extern pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu);
 276 extern int get_remote_cache_cpu(pgprot_t prot);
 277
 278 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 279 {
 280         return hv_pte_set_pa(prot, PFN_PHYS(pfn));
 281 }
 282
 283 /* Support for priority mappings. */
 284 extern void start_mm_caching(struct mm_struct *mm);
 285 extern void check_mm_caching(struct mm_struct *prev, struct mm_struct *next);
 286
 287 /*
 288  * Encode and de-code a swap entry (see <linux/swapops.h>).
 289  * We put the swap file type+offset in the 32 high bits;
 290  * I believe we can just leave the low bits clear.
 291  */
 292 #define __swp_type(swp)         ((swp).val & 0x1f)
 293 #define __swp_offset(swp)       ((swp).val >> 5)
 294 #define __swp_entry(type, off)  ((swp_entry_t) { (type) | ((off) << 5) })
 295 #define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).val >> 32 })
 296 #define __swp_entry_to_pte(swp) ((pte_t) { (((long long) ((swp).val)) << 32) })
 297
 298 /*
 299  * Conversion functions: convert a page and protection to a page entry,
 300  * and a page entry and page directory to the page they refer to.
 301  */
 302
 303 #define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 304
 305 /*
 306  * If we are doing an mprotect(), just accept the new vma->vm_page_prot
 307  * value and combine it with the PFN from the old PTE to get a new PTE.
 308  */
 309 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 310 {
 311         return pfn_pte(pte_pfn(pte), newprot);
 312 }
 313
 314 /*
 315  * The pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 316  *
 317  * This macro returns the index of the entry in the pgd page which would
 318  * control the given virtual address.
 319  */
 320 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 321
 322 /*
 323  * pgd_offset() returns a (pgd_t *)
 324  * pgd_index() is used get the offset into the pgd page's array of pgd_t's.
 325  */
 326 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
 327
 328 /*
 329  * A shortcut which implies the use of the kernel's pgd, instead
 330  * of a process's.
 331  */
 332 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 333
 334 #define pte_offset_map(dir, address) pte_offset_kernel(dir, address)
 335 #define pte_unmap(pte) do { } while (0)
 336
 337 /* Clear a non-executable kernel PTE and flush it from the TLB. */
 338 #define kpte_clear_flush(ptep, vaddr)           \
 339 do {                                            \
 340         pte_clear(&init_mm, (vaddr), (ptep));   \
 341         local_flush_tlb_page(FLUSH_NONEXEC, (vaddr), PAGE_SIZE); \
 342 } while (0)
 343
 344 /*
 345  * The kernel page tables contain what we need, and we flush when we
 346  * change specific page table entries.
 347  */
 348 #define update_mmu_cache(vma, address, pte) do { } while (0)
 349
 350 #ifdef CONFIG_FLATMEM
 351 #define kern_addr_valid(addr)   (1)
 352 #endif /* CONFIG_FLATMEM */
 353
 354 extern void vmalloc_sync_all(void);
 355
 356 #endif /* !__ASSEMBLY__ */
 357
 358 #ifdef __tilegx__
 359 #include <asm/pgtable_64.h>
 360 #else
 361 #include <asm/pgtable_32.h>
 362 #endif
 363
 364 #ifndef __ASSEMBLY__
 365
 366 static inline int pmd_none(pmd_t pmd)
 367 {
 368         /*
 369          * Only check low word on 32-bit platforms, since it might be
 370          * out of sync with upper half.
 371          */
 372         return (unsigned long)pmd_val(pmd) == 0;
 373 }
 374
 375 static inline int pmd_present(pmd_t pmd)
 376 {
 377         return pmd_val(pmd) & _PAGE_PRESENT;
 378 }
 379
 380 static inline int pmd_bad(pmd_t pmd)
 381 {
 382         return ((pmd_val(pmd) & _PAGE_ALL) != _PAGE_TABLE);
 383 }
 384
 385 static inline unsigned long pages_to_mb(unsigned long npg)
 386 {
 387         return npg >> (20 - PAGE_SHIFT);
 388 }
 389
 390 /*
 391  * The pmd can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 392  *
 393  * This function returns the index of the entry in the pmd which would
 394  * control the given virtual address.
 395  */
 396 static inline unsigned long pmd_index(unsigned long address)
 397 {
 398         return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
 399 }
 400
 401 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 402 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 403                                             unsigned long address,
 404                                             pmd_t *pmdp)
 405 {
 406         return ptep_test_and_clear_young(vma, address, pmdp_ptep(pmdp));
 407 }
 408
 409 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
 410 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 411                                       unsigned long address, pmd_t *pmdp)
 412 {
 413         ptep_set_wrprotect(mm, address, pmdp_ptep(pmdp));
 414 }
 415
 416
 417 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 418 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 419                                             unsigned long address,
 420                                             pmd_t *pmdp)
 421 {
 422         return pte_pmd(ptep_get_and_clear(mm, address, pmdp_ptep(pmdp)));
 423 }
 424
 425 static inline void __set_pmd(pmd_t *pmdp, pmd_t pmdval)
 426 {
 427         set_pte(pmdp_ptep(pmdp), pmd_pte(pmdval));
 428 }
 429
 430 #define set_pmd_at(mm, addr, pmdp, pmdval) __set_pmd(pmdp, pmdval)
 431
 432 /* Create a pmd from a PTFN. */
 433 static inline pmd_t ptfn_pmd(unsigned long ptfn, pgprot_t prot)
 434 {
 435         return pte_pmd(hv_pte_set_ptfn(prot, ptfn));
 436 }
 437
 438 /* Return the page-table frame number (ptfn) that a pmd_t points at. */
 439 #define pmd_ptfn(pmd) hv_pte_get_ptfn(pmd_pte(pmd))
 440
 441 /*
 442  * A given kernel pmd_t maps to a specific virtual address (either a
 443  * kernel huge page or a kernel pte_t table).  Since kernel pte_t
 444  * tables can be aligned at sub-page granularity, this function can
 445  * return non-page-aligned pointers, despite its name.
 446  */
 447 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 448 {
 449         phys_addr_t pa =
 450                 (phys_addr_t)pmd_ptfn(pmd) << HV_LOG2_PAGE_TABLE_ALIGN;
 451         return (unsigned long)__va(pa);
 452 }
 453
 454 /*
 455  * A pmd_t points to the base of a huge page or to a pte_t array.
 456  * If a pte_t array, since we can have multiple per page, we don't
 457  * have a one-to-one mapping of pmd_t's to pages.  However, this is
 458  * OK for pte_lockptr(), since we just end up with potentially one
 459  * lock being used for several pte_t arrays.
 460  */
 461 #define pmd_page(pmd) pfn_to_page(PFN_DOWN(HV_PTFN_TO_CPA(pmd_ptfn(pmd))))
 462
 463 static inline void pmd_clear(pmd_t *pmdp)
 464 {
 465         __pte_clear(pmdp_ptep(pmdp));
 466 }
 467
 468 #define pmd_mknotpresent(pmd)   pte_pmd(pte_mknotpresent(pmd_pte(pmd)))
 469 #define pmd_young(pmd)          pte_young(pmd_pte(pmd))
 470 #define pmd_mkyoung(pmd)        pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 471 #define pmd_mkold(pmd)          pte_pmd(pte_mkold(pmd_pte(pmd)))
 472 #define pmd_mkwrite(pmd)        pte_pmd(pte_mkwrite(pmd_pte(pmd)))
 473 #define pmd_write(pmd)          pte_write(pmd_pte(pmd))
 474 #define pmd_wrprotect(pmd)      pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 475 #define pmd_mkdirty(pmd)        pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 476 #define pmd_huge_page(pmd)      pte_huge(pmd_pte(pmd))
 477 #define pmd_mkhuge(pmd)         pte_pmd(pte_mkhuge(pmd_pte(pmd)))
 478 #define __HAVE_ARCH_PMD_WRITE
 479
 480 #define pfn_pmd(pfn, pgprot)    pte_pmd(pfn_pte((pfn), (pgprot)))
 481 #define pmd_pfn(pmd)            pte_pfn(pmd_pte(pmd))
 482 #define mk_pmd(page, pgprot)    pfn_pmd(page_to_pfn(page), (pgprot))
 483
 484 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 485 {
 486         return pfn_pmd(pmd_pfn(pmd), newprot);
 487 }
 488
 489 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 490 #define pmd_trans_huge pmd_huge_page
 491 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 492
 493 /*
 494  * The pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 495  *
 496  * This macro returns the index of the entry in the pte page which would
 497  * control the given virtual address.
 498  */
 499 static inline unsigned long pte_index(unsigned long address)
 500 {
 501         return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
 502 }
 503
 504 static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
 505 {
 506        return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
 507 }
 508
 509 #include <asm-generic/pgtable.h>
 510
 511 /* Support /proc/NN/pgtable API. */
 512 struct seq_file;
 513 int arch_proc_pgtable_show(struct seq_file *m, struct mm_struct *mm,
 514                            unsigned long vaddr, unsigned long pagesize,
 515                            pte_t *ptep, void **datap);
 516
 517 #endif /* !__ASSEMBLY__ */
 518
 519 #endif /* _ASM_TILE_PGTABLE_H */