2 * Copyright (C) 2012 Regents of the University of California
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.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #ifndef _ASM_RISCV_PGTABLE_H
15 #define _ASM_RISCV_PGTABLE_H
17 #include <linux/mmzone.h>
19 #include <asm/pgtable-bits.h>
25 /* Page Upper Directory not used in RISC-V */
26 #include <asm-generic/pgtable-nopud.h>
28 #include <asm/tlbflush.h>
29 #include <linux/mm_types.h>
32 #include <asm/pgtable-64.h>
34 #include <asm/pgtable-32.h>
35 #endif /* CONFIG_64BIT */
37 /* Number of entries in the page global directory */
38 #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t))
39 /* Number of entries in the page table */
40 #define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
42 /* Number of PGD entries that a user-mode program can use */
43 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
44 #define FIRST_USER_ADDRESS 0
46 /* Page protection bits */
47 #define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
49 #define PAGE_NONE __pgprot(0)
50 #define PAGE_READ __pgprot(_PAGE_BASE | _PAGE_READ)
51 #define PAGE_WRITE __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
52 #define PAGE_EXEC __pgprot(_PAGE_BASE | _PAGE_EXEC)
53 #define PAGE_READ_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
54 #define PAGE_WRITE_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | \
55 _PAGE_EXEC | _PAGE_WRITE)
57 #define PAGE_COPY PAGE_READ
58 #define PAGE_COPY_EXEC PAGE_EXEC
59 #define PAGE_COPY_READ_EXEC PAGE_READ_EXEC
60 #define PAGE_SHARED PAGE_WRITE
61 #define PAGE_SHARED_EXEC PAGE_WRITE_EXEC
63 #define _PAGE_KERNEL (_PAGE_READ \
69 #define PAGE_KERNEL __pgprot(_PAGE_KERNEL)
70 #define PAGE_KERNEL_EXEC __pgprot(_PAGE_KERNEL | _PAGE_EXEC)
72 extern pgd_t swapper_pg_dir[];
74 /* MAP_PRIVATE permissions: xwr (copy-on-write) */
75 #define __P000 PAGE_NONE
76 #define __P001 PAGE_READ
77 #define __P010 PAGE_COPY
78 #define __P011 PAGE_COPY
79 #define __P100 PAGE_EXEC
80 #define __P101 PAGE_READ_EXEC
81 #define __P110 PAGE_COPY_EXEC
82 #define __P111 PAGE_COPY_READ_EXEC
84 /* MAP_SHARED permissions: xwr */
85 #define __S000 PAGE_NONE
86 #define __S001 PAGE_READ
87 #define __S010 PAGE_SHARED
88 #define __S011 PAGE_SHARED
89 #define __S100 PAGE_EXEC
90 #define __S101 PAGE_READ_EXEC
91 #define __S110 PAGE_SHARED_EXEC
92 #define __S111 PAGE_SHARED_EXEC
95 * ZERO_PAGE is a global shared page that is always zero,
96 * used for zero-mapped memory areas, etc.
98 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
99 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
101 static inline int pmd_present(pmd_t pmd)
103 return (pmd_val(pmd) & _PAGE_PRESENT);
106 static inline int pmd_none(pmd_t pmd)
108 return (pmd_val(pmd) == 0);
111 static inline int pmd_bad(pmd_t pmd)
113 return !pmd_present(pmd);
116 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
121 static inline void pmd_clear(pmd_t *pmdp)
123 set_pmd(pmdp, __pmd(0));
127 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
129 return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
132 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
134 /* Locate an entry in the page global directory */
135 static inline pgd_t *pgd_offset(const struct mm_struct *mm, unsigned long addr)
137 return mm->pgd + pgd_index(addr);
139 /* Locate an entry in the kernel page global directory */
140 #define pgd_offset_k(addr) pgd_offset(&init_mm, (addr))
142 static inline struct page *pmd_page(pmd_t pmd)
144 return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
147 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
149 return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
152 /* Yields the page frame number (PFN) of a page table entry */
153 static inline unsigned long pte_pfn(pte_t pte)
155 return (pte_val(pte) >> _PAGE_PFN_SHIFT);
158 #define pte_page(x) pfn_to_page(pte_pfn(x))
160 /* Constructs a page table entry */
161 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
163 return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
166 static inline pte_t mk_pte(struct page *page, pgprot_t prot)
168 return pfn_pte(page_to_pfn(page), prot);
171 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
173 static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr)
175 return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(addr);
178 #define pte_offset_map(dir, addr) pte_offset_kernel((dir), (addr))
179 #define pte_unmap(pte) ((void)(pte))
181 static inline int pte_present(pte_t pte)
183 return (pte_val(pte) & _PAGE_PRESENT);
186 static inline int pte_none(pte_t pte)
188 return (pte_val(pte) == 0);
191 static inline int pte_write(pte_t pte)
193 return pte_val(pte) & _PAGE_WRITE;
196 static inline int pte_exec(pte_t pte)
198 return pte_val(pte) & _PAGE_EXEC;
201 static inline int pte_huge(pte_t pte)
203 return pte_present(pte)
204 && (pte_val(pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
207 static inline int pte_dirty(pte_t pte)
209 return pte_val(pte) & _PAGE_DIRTY;
212 static inline int pte_young(pte_t pte)
214 return pte_val(pte) & _PAGE_ACCESSED;
217 static inline int pte_special(pte_t pte)
219 return pte_val(pte) & _PAGE_SPECIAL;
222 /* static inline pte_t pte_rdprotect(pte_t pte) */
224 static inline pte_t pte_wrprotect(pte_t pte)
226 return __pte(pte_val(pte) & ~(_PAGE_WRITE));
229 /* static inline pte_t pte_mkread(pte_t pte) */
231 static inline pte_t pte_mkwrite(pte_t pte)
233 return __pte(pte_val(pte) | _PAGE_WRITE);
236 /* static inline pte_t pte_mkexec(pte_t pte) */
238 static inline pte_t pte_mkdirty(pte_t pte)
240 return __pte(pte_val(pte) | _PAGE_DIRTY);
243 static inline pte_t pte_mkclean(pte_t pte)
245 return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
248 static inline pte_t pte_mkyoung(pte_t pte)
250 return __pte(pte_val(pte) | _PAGE_ACCESSED);
253 static inline pte_t pte_mkold(pte_t pte)
255 return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
258 static inline pte_t pte_mkspecial(pte_t pte)
260 return __pte(pte_val(pte) | _PAGE_SPECIAL);
263 /* Modify page protection bits */
264 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
266 return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
269 #define pgd_ERROR(e) \
270 pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
273 /* Commit new configuration to MMU hardware */
274 static inline void update_mmu_cache(struct vm_area_struct *vma,
275 unsigned long address, pte_t *ptep)
278 * The kernel assumes that TLBs don't cache invalid entries, but
279 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
280 * cache flush; it is necessary even after writing invalid entries.
281 * Relying on flush_tlb_fix_spurious_fault would suffice, but
282 * the extra traps reduce performance. So, eagerly SFENCE.VMA.
284 local_flush_tlb_page(address);
287 #define __HAVE_ARCH_PTE_SAME
288 static inline int pte_same(pte_t pte_a, pte_t pte_b)
290 return pte_val(pte_a) == pte_val(pte_b);
294 * Certain architectures need to do special things when PTEs within
295 * a page table are directly modified. Thus, the following hook is
298 static inline void set_pte(pte_t *ptep, pte_t pteval)
303 void flush_icache_pte(pte_t pte);
305 static inline void set_pte_at(struct mm_struct *mm,
306 unsigned long addr, pte_t *ptep, pte_t pteval)
308 if (pte_present(pteval) && pte_exec(pteval))
309 flush_icache_pte(pteval);
311 set_pte(ptep, pteval);
314 static inline void pte_clear(struct mm_struct *mm,
315 unsigned long addr, pte_t *ptep)
317 set_pte_at(mm, addr, ptep, __pte(0));
320 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
321 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
322 unsigned long address, pte_t *ptep,
323 pte_t entry, int dirty)
325 if (!pte_same(*ptep, entry))
326 set_pte_at(vma->vm_mm, address, ptep, entry);
328 * update_mmu_cache will unconditionally execute, handling both
329 * the case that the PTE changed and the spurious fault case.
334 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
335 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
336 unsigned long address, pte_t *ptep)
338 return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
341 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
342 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
343 unsigned long address,
346 if (!pte_young(*ptep))
348 return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
351 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
352 static inline void ptep_set_wrprotect(struct mm_struct *mm,
353 unsigned long address, pte_t *ptep)
355 atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
358 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
359 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
360 unsigned long address, pte_t *ptep)
363 * This comment is borrowed from x86, but applies equally to RISC-V:
365 * Clearing the accessed bit without a TLB flush
366 * doesn't cause data corruption. [ It could cause incorrect
367 * page aging and the (mistaken) reclaim of hot pages, but the
368 * chance of that should be relatively low. ]
370 * So as a performance optimization don't flush the TLB when
371 * clearing the accessed bit, it will eventually be flushed by
372 * a context switch or a VM operation anyway. [ In the rare
373 * event of it not getting flushed for a long time the delay
374 * shouldn't really matter because there's no real memory
375 * pressure for swapout to react to. ]
377 return ptep_test_and_clear_young(vma, address, ptep);
381 * Encode and decode a swap entry
383 * Format of swap PTE:
384 * bit 0: _PAGE_PRESENT (zero)
385 * bit 1: reserved for future use (zero)
386 * bits 2 to 6: swap type
387 * bits 7 to XLEN-1: swap offset
389 #define __SWP_TYPE_SHIFT 2
390 #define __SWP_TYPE_BITS 5
391 #define __SWP_TYPE_MASK ((1UL << __SWP_TYPE_BITS) - 1)
392 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
394 #define MAX_SWAPFILES_CHECK() \
395 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
397 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
398 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
399 #define __swp_entry(type, offset) ((swp_entry_t) \
400 { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
402 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
403 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
405 #ifdef CONFIG_FLATMEM
406 #define kern_addr_valid(addr) (1) /* FIXME */
409 extern void paging_init(void);
411 static inline void pgtable_cache_init(void)
413 /* No page table caches to initialize */
416 #endif /* CONFIG_MMU */
418 #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
419 #define VMALLOC_END (PAGE_OFFSET - 1)
420 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
423 * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
424 * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
427 #define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2)
429 #define TASK_SIZE VMALLOC_START
432 #include <asm-generic/pgtable.h>
434 #endif /* !__ASSEMBLY__ */
436 #endif /* _ASM_RISCV_PGTABLE_H */