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

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2012 Regents of the University of California
   4 */
   5
   6#ifndef _ASM_RISCV_PGTABLE_H
   7#define _ASM_RISCV_PGTABLE_H
   8
   9#include <linux/mmzone.h>
  10#include <linux/sizes.h>
  11
  12#include <asm/pgtable-bits.h>
  13
  14#ifndef CONFIG_MMU
  15#define KERNEL_LINK_ADDR        PAGE_OFFSET
  16#else
  17
  18#define ADDRESS_SPACE_END       (UL(-1))
  19
  20#ifdef CONFIG_64BIT
  21/* Leave 2GB for kernel and BPF at the end of the address space */
  22#define KERNEL_LINK_ADDR        (ADDRESS_SPACE_END - SZ_2G + 1)
  23#else
  24#define KERNEL_LINK_ADDR        PAGE_OFFSET
  25#endif
  26
  27#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
  28#define VMALLOC_END      (PAGE_OFFSET - 1)
  29#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
  30
  31#define BPF_JIT_REGION_SIZE     (SZ_128M)
  32#ifdef CONFIG_64BIT
  33#define BPF_JIT_REGION_START    (BPF_JIT_REGION_END - BPF_JIT_REGION_SIZE)
  34#define BPF_JIT_REGION_END      (MODULES_END)
  35#else
  36#define BPF_JIT_REGION_START    (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
  37#define BPF_JIT_REGION_END      (VMALLOC_END)
  38#endif
  39
  40/* Modules always live before the kernel */
  41#ifdef CONFIG_64BIT
  42#define MODULES_VADDR   (PFN_ALIGN((unsigned long)&_end) - SZ_2G)
  43#define MODULES_END     (PFN_ALIGN((unsigned long)&_start))
  44#endif
  45
  46/*
  47 * Roughly size the vmemmap space to be large enough to fit enough
  48 * struct pages to map half the virtual address space. Then
  49 * position vmemmap directly below the VMALLOC region.
  50 */
  51#define VMEMMAP_SHIFT \
  52        (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
  53#define VMEMMAP_SIZE    BIT(VMEMMAP_SHIFT)
  54#define VMEMMAP_END     (VMALLOC_START - 1)
  55#define VMEMMAP_START   (VMALLOC_START - VMEMMAP_SIZE)
  56
  57/*
  58 * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
  59 * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
  60 */
  61#define vmemmap         ((struct page *)VMEMMAP_START)
  62
  63#define PCI_IO_SIZE      SZ_16M
  64#define PCI_IO_END       VMEMMAP_START
  65#define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
  66
  67#define FIXADDR_TOP      PCI_IO_START
  68#ifdef CONFIG_64BIT
  69#define FIXADDR_SIZE     PMD_SIZE
  70#else
  71#define FIXADDR_SIZE     PGDIR_SIZE
  72#endif
  73#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
  74
  75#endif
  76
  77#ifdef CONFIG_XIP_KERNEL
  78#define XIP_OFFSET              SZ_8M
  79#else
  80#define XIP_OFFSET              0
  81#endif
  82
  83#ifndef __ASSEMBLY__
  84
  85/* Page Upper Directory not used in RISC-V */
  86#include <asm-generic/pgtable-nopud.h>
  87#include <asm/page.h>
  88#include <asm/tlbflush.h>
  89#include <linux/mm_types.h>
  90
  91#ifdef CONFIG_64BIT
  92#include <asm/pgtable-64.h>
  93#else
  94#include <asm/pgtable-32.h>
  95#endif /* CONFIG_64BIT */
  96
  97#ifdef CONFIG_XIP_KERNEL
  98#define XIP_FIXUP(addr) ({                                                      \
  99        uintptr_t __a = (uintptr_t)(addr);                                      \
 100        (__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?  \
 101                __a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
 102                __a;                                                            \
 103        })
 104#else
 105#define XIP_FIXUP(addr)         (addr)
 106#endif /* CONFIG_XIP_KERNEL */
 107
 108#ifdef CONFIG_MMU
 109/* Number of entries in the page global directory */
 110#define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
 111/* Number of entries in the page table */
 112#define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
 113
 114/* Number of PGD entries that a user-mode program can use */
 115#define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
 116
 117/* Page protection bits */
 118#define _PAGE_BASE      (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
 119
 120#define PAGE_NONE               __pgprot(_PAGE_PROT_NONE)
 121#define PAGE_READ               __pgprot(_PAGE_BASE | _PAGE_READ)
 122#define PAGE_WRITE              __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
 123#define PAGE_EXEC               __pgprot(_PAGE_BASE | _PAGE_EXEC)
 124#define PAGE_READ_EXEC          __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
 125#define PAGE_WRITE_EXEC         __pgprot(_PAGE_BASE | _PAGE_READ |      \
 126                                         _PAGE_EXEC | _PAGE_WRITE)
 127
 128#define PAGE_COPY               PAGE_READ
 129#define PAGE_COPY_EXEC          PAGE_EXEC
 130#define PAGE_COPY_READ_EXEC     PAGE_READ_EXEC
 131#define PAGE_SHARED             PAGE_WRITE
 132#define PAGE_SHARED_EXEC        PAGE_WRITE_EXEC
 133
 134#define _PAGE_KERNEL            (_PAGE_READ \
 135                                | _PAGE_WRITE \
 136                                | _PAGE_PRESENT \
 137                                | _PAGE_ACCESSED \
 138                                | _PAGE_DIRTY \
 139                                | _PAGE_GLOBAL)
 140
 141#define PAGE_KERNEL             __pgprot(_PAGE_KERNEL)
 142#define PAGE_KERNEL_READ        __pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
 143#define PAGE_KERNEL_EXEC        __pgprot(_PAGE_KERNEL | _PAGE_EXEC)
 144#define PAGE_KERNEL_READ_EXEC   __pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
 145                                         | _PAGE_EXEC)
 146
 147#define PAGE_TABLE              __pgprot(_PAGE_TABLE)
 148
 149/*
 150 * The RISC-V ISA doesn't yet specify how to query or modify PMAs, so we can't
 151 * change the properties of memory regions.
 152 */
 153#define _PAGE_IOREMAP _PAGE_KERNEL
 154
 155extern pgd_t swapper_pg_dir[];
 156
 157/* MAP_PRIVATE permissions: xwr (copy-on-write) */
 158#define __P000  PAGE_NONE
 159#define __P001  PAGE_READ
 160#define __P010  PAGE_COPY
 161#define __P011  PAGE_COPY
 162#define __P100  PAGE_EXEC
 163#define __P101  PAGE_READ_EXEC
 164#define __P110  PAGE_COPY_EXEC
 165#define __P111  PAGE_COPY_READ_EXEC
 166
 167/* MAP_SHARED permissions: xwr */
 168#define __S000  PAGE_NONE
 169#define __S001  PAGE_READ
 170#define __S010  PAGE_SHARED
 171#define __S011  PAGE_SHARED
 172#define __S100  PAGE_EXEC
 173#define __S101  PAGE_READ_EXEC
 174#define __S110  PAGE_SHARED_EXEC
 175#define __S111  PAGE_SHARED_EXEC
 176
 177#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 178static inline int pmd_present(pmd_t pmd)
 179{
 180        /*
 181         * Checking for _PAGE_LEAF is needed too because:
 182         * When splitting a THP, split_huge_page() will temporarily clear
 183         * the present bit, in this situation, pmd_present() and
 184         * pmd_trans_huge() still needs to return true.
 185         */
 186        return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
 187}
 188#else
 189static inline int pmd_present(pmd_t pmd)
 190{
 191        return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
 192}
 193#endif
 194
 195static inline int pmd_none(pmd_t pmd)
 196{
 197        return (pmd_val(pmd) == 0);
 198}
 199
 200static inline int pmd_bad(pmd_t pmd)
 201{
 202        return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
 203}
 204
 205#define pmd_leaf        pmd_leaf
 206static inline int pmd_leaf(pmd_t pmd)
 207{
 208        return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
 209}
 210
 211static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 212{
 213        *pmdp = pmd;
 214}
 215
 216static inline void pmd_clear(pmd_t *pmdp)
 217{
 218        set_pmd(pmdp, __pmd(0));
 219}
 220
 221static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
 222{
 223        return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
 224}
 225
 226static inline unsigned long _pgd_pfn(pgd_t pgd)
 227{
 228        return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
 229}
 230
 231static inline struct page *pmd_page(pmd_t pmd)
 232{
 233        return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
 234}
 235
 236static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 237{
 238        return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
 239}
 240
 241static inline pte_t pmd_pte(pmd_t pmd)
 242{
 243        return __pte(pmd_val(pmd));
 244}
 245
 246static inline pte_t pud_pte(pud_t pud)
 247{
 248        return __pte(pud_val(pud));
 249}
 250
 251/* Yields the page frame number (PFN) of a page table entry */
 252static inline unsigned long pte_pfn(pte_t pte)
 253{
 254        return (pte_val(pte) >> _PAGE_PFN_SHIFT);
 255}
 256
 257#define pte_page(x)     pfn_to_page(pte_pfn(x))
 258
 259/* Constructs a page table entry */
 260static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 261{
 262        return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
 263}
 264
 265#define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
 266
 267static inline int pte_present(pte_t pte)
 268{
 269        return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
 270}
 271
 272static inline int pte_none(pte_t pte)
 273{
 274        return (pte_val(pte) == 0);
 275}
 276
 277static inline int pte_write(pte_t pte)
 278{
 279        return pte_val(pte) & _PAGE_WRITE;
 280}
 281
 282static inline int pte_exec(pte_t pte)
 283{
 284        return pte_val(pte) & _PAGE_EXEC;
 285}
 286
 287static inline int pte_huge(pte_t pte)
 288{
 289        return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
 290}
 291
 292static inline int pte_dirty(pte_t pte)
 293{
 294        return pte_val(pte) & _PAGE_DIRTY;
 295}
 296
 297static inline int pte_young(pte_t pte)
 298{
 299        return pte_val(pte) & _PAGE_ACCESSED;
 300}
 301
 302static inline int pte_special(pte_t pte)
 303{
 304        return pte_val(pte) & _PAGE_SPECIAL;
 305}
 306
 307/* static inline pte_t pte_rdprotect(pte_t pte) */
 308
 309static inline pte_t pte_wrprotect(pte_t pte)
 310{
 311        return __pte(pte_val(pte) & ~(_PAGE_WRITE));
 312}
 313
 314/* static inline pte_t pte_mkread(pte_t pte) */
 315
 316static inline pte_t pte_mkwrite(pte_t pte)
 317{
 318        return __pte(pte_val(pte) | _PAGE_WRITE);
 319}
 320
 321/* static inline pte_t pte_mkexec(pte_t pte) */
 322
 323static inline pte_t pte_mkdirty(pte_t pte)
 324{
 325        return __pte(pte_val(pte) | _PAGE_DIRTY);
 326}
 327
 328static inline pte_t pte_mkclean(pte_t pte)
 329{
 330        return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
 331}
 332
 333static inline pte_t pte_mkyoung(pte_t pte)
 334{
 335        return __pte(pte_val(pte) | _PAGE_ACCESSED);
 336}
 337
 338static inline pte_t pte_mkold(pte_t pte)
 339{
 340        return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
 341}
 342
 343static inline pte_t pte_mkspecial(pte_t pte)
 344{
 345        return __pte(pte_val(pte) | _PAGE_SPECIAL);
 346}
 347
 348static inline pte_t pte_mkhuge(pte_t pte)
 349{
 350        return pte;
 351}
 352
 353#ifdef CONFIG_NUMA_BALANCING
 354/*
 355 * See the comment in include/asm-generic/pgtable.h
 356 */
 357static inline int pte_protnone(pte_t pte)
 358{
 359        return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
 360}
 361
 362static inline int pmd_protnone(pmd_t pmd)
 363{
 364        return pte_protnone(pmd_pte(pmd));
 365}
 366#endif
 367
 368/* Modify page protection bits */
 369static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 370{
 371        return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
 372}
 373
 374#define pgd_ERROR(e) \
 375        pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
 376
 377
 378/* Commit new configuration to MMU hardware */
 379static inline void update_mmu_cache(struct vm_area_struct *vma,
 380        unsigned long address, pte_t *ptep)
 381{
 382        /*
 383         * The kernel assumes that TLBs don't cache invalid entries, but
 384         * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
 385         * cache flush; it is necessary even after writing invalid entries.
 386         * Relying on flush_tlb_fix_spurious_fault would suffice, but
 387         * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
 388         */
 389        local_flush_tlb_page(address);
 390}
 391
 392static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 393                unsigned long address, pmd_t *pmdp)
 394{
 395        pte_t *ptep = (pte_t *)pmdp;
 396
 397        update_mmu_cache(vma, address, ptep);
 398}
 399
 400#define __HAVE_ARCH_PTE_SAME
 401static inline int pte_same(pte_t pte_a, pte_t pte_b)
 402{
 403        return pte_val(pte_a) == pte_val(pte_b);
 404}
 405
 406/*
 407 * Certain architectures need to do special things when PTEs within
 408 * a page table are directly modified.  Thus, the following hook is
 409 * made available.
 410 */
 411static inline void set_pte(pte_t *ptep, pte_t pteval)
 412{
 413        *ptep = pteval;
 414}
 415
 416void flush_icache_pte(pte_t pte);
 417
 418static inline void set_pte_at(struct mm_struct *mm,
 419        unsigned long addr, pte_t *ptep, pte_t pteval)
 420{
 421        if (pte_present(pteval) && pte_exec(pteval))
 422                flush_icache_pte(pteval);
 423
 424        set_pte(ptep, pteval);
 425}
 426
 427static inline void pte_clear(struct mm_struct *mm,
 428        unsigned long addr, pte_t *ptep)
 429{
 430        set_pte_at(mm, addr, ptep, __pte(0));
 431}
 432
 433#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 434static inline int ptep_set_access_flags(struct vm_area_struct *vma,
 435                                        unsigned long address, pte_t *ptep,
 436                                        pte_t entry, int dirty)
 437{
 438        if (!pte_same(*ptep, entry))
 439                set_pte_at(vma->vm_mm, address, ptep, entry);
 440        /*
 441         * update_mmu_cache will unconditionally execute, handling both
 442         * the case that the PTE changed and the spurious fault case.
 443         */
 444        return true;
 445}
 446
 447#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 448static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 449                                       unsigned long address, pte_t *ptep)
 450{
 451        return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
 452}
 453
 454#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 455static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 456                                            unsigned long address,
 457                                            pte_t *ptep)
 458{
 459        if (!pte_young(*ptep))
 460                return 0;
 461        return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
 462}
 463
 464#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 465static inline void ptep_set_wrprotect(struct mm_struct *mm,
 466                                      unsigned long address, pte_t *ptep)
 467{
 468        atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
 469}
 470
 471#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 472static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 473                                         unsigned long address, pte_t *ptep)
 474{
 475        /*
 476         * This comment is borrowed from x86, but applies equally to RISC-V:
 477         *
 478         * Clearing the accessed bit without a TLB flush
 479         * doesn't cause data corruption. [ It could cause incorrect
 480         * page aging and the (mistaken) reclaim of hot pages, but the
 481         * chance of that should be relatively low. ]
 482         *
 483         * So as a performance optimization don't flush the TLB when
 484         * clearing the accessed bit, it will eventually be flushed by
 485         * a context switch or a VM operation anyway. [ In the rare
 486         * event of it not getting flushed for a long time the delay
 487         * shouldn't really matter because there's no real memory
 488         * pressure for swapout to react to. ]
 489         */
 490        return ptep_test_and_clear_young(vma, address, ptep);
 491}
 492
 493/*
 494 * THP functions
 495 */
 496static inline pmd_t pte_pmd(pte_t pte)
 497{
 498        return __pmd(pte_val(pte));
 499}
 500
 501static inline pmd_t pmd_mkhuge(pmd_t pmd)
 502{
 503        return pmd;
 504}
 505
 506static inline pmd_t pmd_mkinvalid(pmd_t pmd)
 507{
 508        return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
 509}
 510
 511#define __pmd_to_phys(pmd)  (pmd_val(pmd) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
 512
 513static inline unsigned long pmd_pfn(pmd_t pmd)
 514{
 515        return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
 516}
 517
 518static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 519{
 520        return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
 521}
 522
 523#define pmd_write pmd_write
 524static inline int pmd_write(pmd_t pmd)
 525{
 526        return pte_write(pmd_pte(pmd));
 527}
 528
 529static inline int pmd_dirty(pmd_t pmd)
 530{
 531        return pte_dirty(pmd_pte(pmd));
 532}
 533
 534static inline int pmd_young(pmd_t pmd)
 535{
 536        return pte_young(pmd_pte(pmd));
 537}
 538
 539static inline pmd_t pmd_mkold(pmd_t pmd)
 540{
 541        return pte_pmd(pte_mkold(pmd_pte(pmd)));
 542}
 543
 544static inline pmd_t pmd_mkyoung(pmd_t pmd)
 545{
 546        return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
 547}
 548
 549static inline pmd_t pmd_mkwrite(pmd_t pmd)
 550{
 551        return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
 552}
 553
 554static inline pmd_t pmd_wrprotect(pmd_t pmd)
 555{
 556        return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
 557}
 558
 559static inline pmd_t pmd_mkclean(pmd_t pmd)
 560{
 561        return pte_pmd(pte_mkclean(pmd_pte(pmd)));
 562}
 563
 564static inline pmd_t pmd_mkdirty(pmd_t pmd)
 565{
 566        return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
 567}
 568
 569static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 570                                pmd_t *pmdp, pmd_t pmd)
 571{
 572        return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
 573}
 574
 575static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
 576                                pud_t *pudp, pud_t pud)
 577{
 578        return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
 579}
 580
 581#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 582static inline int pmd_trans_huge(pmd_t pmd)
 583{
 584        return pmd_leaf(pmd);
 585}
 586
 587#define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
 588static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 589                                        unsigned long address, pmd_t *pmdp,
 590                                        pmd_t entry, int dirty)
 591{
 592        return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
 593}
 594
 595#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 596static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 597                                        unsigned long address, pmd_t *pmdp)
 598{
 599        return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
 600}
 601
 602#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 603static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 604                                        unsigned long address, pmd_t *pmdp)
 605{
 606        return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
 607}
 608
 609#define __HAVE_ARCH_PMDP_SET_WRPROTECT
 610static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 611                                        unsigned long address, pmd_t *pmdp)
 612{
 613        ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
 614}
 615
 616#define pmdp_establish pmdp_establish
 617static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 618                                unsigned long address, pmd_t *pmdp, pmd_t pmd)
 619{
 620        return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
 621}
 622#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 623
 624/*
 625 * Encode and decode a swap entry
 626 *
 627 * Format of swap PTE:
 628 *      bit            0:       _PAGE_PRESENT (zero)
 629 *      bit            1:       _PAGE_PROT_NONE (zero)
 630 *      bits      2 to 6:       swap type
 631 *      bits 7 to XLEN-1:       swap offset
 632 */
 633#define __SWP_TYPE_SHIFT        2
 634#define __SWP_TYPE_BITS         5
 635#define __SWP_TYPE_MASK         ((1UL << __SWP_TYPE_BITS) - 1)
 636#define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 637
 638#define MAX_SWAPFILES_CHECK()   \
 639        BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 640
 641#define __swp_type(x)   (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 642#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
 643#define __swp_entry(type, offset) ((swp_entry_t) \
 644        { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 645
 646#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 647#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
 648
 649/*
 650 * In the RV64 Linux scheme, we give the user half of the virtual-address space
 651 * and give the kernel the other (upper) half.
 652 */
 653#ifdef CONFIG_64BIT
 654#define KERN_VIRT_START (-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
 655#else
 656#define KERN_VIRT_START FIXADDR_START
 657#endif
 658
 659/*
 660 * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
 661 * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
 662 */
 663#ifdef CONFIG_64BIT
 664#define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2)
 665#else
 666#define TASK_SIZE FIXADDR_START
 667#endif
 668
 669#else /* CONFIG_MMU */
 670
 671#define PAGE_SHARED             __pgprot(0)
 672#define PAGE_KERNEL             __pgprot(0)
 673#define swapper_pg_dir          NULL
 674#define TASK_SIZE               0xffffffffUL
 675#define VMALLOC_START           0
 676#define VMALLOC_END             TASK_SIZE
 677
 678#endif /* !CONFIG_MMU */
 679
 680#define kern_addr_valid(addr)   (1) /* FIXME */
 681
 682extern char _start[];
 683extern void *_dtb_early_va;
 684extern uintptr_t _dtb_early_pa;
 685#if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
 686#define dtb_early_va    (*(void **)XIP_FIXUP(&_dtb_early_va))
 687#define dtb_early_pa    (*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
 688#else
 689#define dtb_early_va    _dtb_early_va
 690#define dtb_early_pa    _dtb_early_pa
 691#endif /* CONFIG_XIP_KERNEL */
 692
 693void paging_init(void);
 694void misc_mem_init(void);
 695
 696/*
 697 * ZERO_PAGE is a global shared page that is always zero,
 698 * used for zero-mapped memory areas, etc.
 699 */
 700extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 701#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 702
 703#endif /* !__ASSEMBLY__ */
 704
 705#endif /* _ASM_RISCV_PGTABLE_H */
 706