xref: /openbmc/linux/arch/riscv/include/asm/pgtable.h (revision d15cb3da)
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 #define KERN_VIRT_SIZE		(UL(-1))
17 #else
18 
19 #define ADDRESS_SPACE_END	(UL(-1))
20 
21 #ifdef CONFIG_64BIT
22 /* Leave 2GB for kernel and BPF at the end of the address space */
23 #define KERNEL_LINK_ADDR	(ADDRESS_SPACE_END - SZ_2G + 1)
24 #else
25 #define KERNEL_LINK_ADDR	PAGE_OFFSET
26 #endif
27 
28 /* Number of entries in the page global directory */
29 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
30 /* Number of entries in the page table */
31 #define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
32 
33 /*
34  * Half of the kernel address space (half of the entries of the page global
35  * directory) is for the direct mapping.
36  */
37 #define KERN_VIRT_SIZE          ((PTRS_PER_PGD / 2 * PGDIR_SIZE) / 2)
38 
39 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
40 #define VMALLOC_END      PAGE_OFFSET
41 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
42 
43 #define BPF_JIT_REGION_SIZE	(SZ_128M)
44 #ifdef CONFIG_64BIT
45 #define BPF_JIT_REGION_START	(BPF_JIT_REGION_END - BPF_JIT_REGION_SIZE)
46 #define BPF_JIT_REGION_END	(MODULES_END)
47 #else
48 #define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
49 #define BPF_JIT_REGION_END	(VMALLOC_END)
50 #endif
51 
52 /* Modules always live before the kernel */
53 #ifdef CONFIG_64BIT
54 /* This is used to define the end of the KASAN shadow region */
55 #define MODULES_LOWEST_VADDR	(KERNEL_LINK_ADDR - SZ_2G)
56 #define MODULES_VADDR		(PFN_ALIGN((unsigned long)&_end) - SZ_2G)
57 #define MODULES_END		(PFN_ALIGN((unsigned long)&_start))
58 #endif
59 
60 /*
61  * Roughly size the vmemmap space to be large enough to fit enough
62  * struct pages to map half the virtual address space. Then
63  * position vmemmap directly below the VMALLOC region.
64  */
65 #ifdef CONFIG_64BIT
66 #define VA_BITS		(pgtable_l4_enabled ? 48 : 39)
67 #else
68 #define VA_BITS		32
69 #endif
70 
71 #define VMEMMAP_SHIFT \
72 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
73 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
74 #define VMEMMAP_END	VMALLOC_START
75 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
76 
77 /*
78  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
79  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
80  */
81 #define vmemmap		((struct page *)VMEMMAP_START)
82 
83 #define PCI_IO_SIZE      SZ_16M
84 #define PCI_IO_END       VMEMMAP_START
85 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
86 
87 #define FIXADDR_TOP      PCI_IO_START
88 #ifdef CONFIG_64BIT
89 #define FIXADDR_SIZE     PMD_SIZE
90 #else
91 #define FIXADDR_SIZE     PGDIR_SIZE
92 #endif
93 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
94 
95 #endif
96 
97 #ifdef CONFIG_XIP_KERNEL
98 #define XIP_OFFSET		SZ_32M
99 #define XIP_OFFSET_MASK		(SZ_32M - 1)
100 #else
101 #define XIP_OFFSET		0
102 #endif
103 
104 #ifndef __ASSEMBLY__
105 
106 #include <asm-generic/pgtable-nop4d.h>
107 #include <asm/page.h>
108 #include <asm/tlbflush.h>
109 #include <linux/mm_types.h>
110 
111 #ifdef CONFIG_64BIT
112 #include <asm/pgtable-64.h>
113 #else
114 #include <asm/pgtable-32.h>
115 #endif /* CONFIG_64BIT */
116 
117 #ifdef CONFIG_XIP_KERNEL
118 #define XIP_FIXUP(addr) ({							\
119 	uintptr_t __a = (uintptr_t)(addr);					\
120 	(__a >= CONFIG_XIP_PHYS_ADDR && \
121 	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
122 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
123 		__a;								\
124 	})
125 #else
126 #define XIP_FIXUP(addr)		(addr)
127 #endif /* CONFIG_XIP_KERNEL */
128 
129 struct pt_alloc_ops {
130 	pte_t *(*get_pte_virt)(phys_addr_t pa);
131 	phys_addr_t (*alloc_pte)(uintptr_t va);
132 #ifndef __PAGETABLE_PMD_FOLDED
133 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
134 	phys_addr_t (*alloc_pmd)(uintptr_t va);
135 	pud_t *(*get_pud_virt)(phys_addr_t pa);
136 	phys_addr_t (*alloc_pud)(uintptr_t va);
137 #endif
138 };
139 
140 extern struct pt_alloc_ops pt_ops __initdata;
141 
142 #ifdef CONFIG_MMU
143 /* Number of PGD entries that a user-mode program can use */
144 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
145 
146 /* Page protection bits */
147 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
148 
149 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
150 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
151 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
152 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
153 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
154 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
155 					 _PAGE_EXEC | _PAGE_WRITE)
156 
157 #define PAGE_COPY		PAGE_READ
158 #define PAGE_COPY_EXEC		PAGE_EXEC
159 #define PAGE_COPY_READ_EXEC	PAGE_READ_EXEC
160 #define PAGE_SHARED		PAGE_WRITE
161 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
162 
163 #define _PAGE_KERNEL		(_PAGE_READ \
164 				| _PAGE_WRITE \
165 				| _PAGE_PRESENT \
166 				| _PAGE_ACCESSED \
167 				| _PAGE_DIRTY \
168 				| _PAGE_GLOBAL)
169 
170 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
171 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
172 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
173 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
174 					 | _PAGE_EXEC)
175 
176 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
177 
178 /*
179  * The RISC-V ISA doesn't yet specify how to query or modify PMAs, so we can't
180  * change the properties of memory regions.
181  */
182 #define _PAGE_IOREMAP _PAGE_KERNEL
183 
184 extern pgd_t swapper_pg_dir[];
185 
186 /* MAP_PRIVATE permissions: xwr (copy-on-write) */
187 #define __P000	PAGE_NONE
188 #define __P001	PAGE_READ
189 #define __P010	PAGE_COPY
190 #define __P011	PAGE_COPY
191 #define __P100	PAGE_EXEC
192 #define __P101	PAGE_READ_EXEC
193 #define __P110	PAGE_COPY_EXEC
194 #define __P111	PAGE_COPY_READ_EXEC
195 
196 /* MAP_SHARED permissions: xwr */
197 #define __S000	PAGE_NONE
198 #define __S001	PAGE_READ
199 #define __S010	PAGE_SHARED
200 #define __S011	PAGE_SHARED
201 #define __S100	PAGE_EXEC
202 #define __S101	PAGE_READ_EXEC
203 #define __S110	PAGE_SHARED_EXEC
204 #define __S111	PAGE_SHARED_EXEC
205 
206 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
207 static inline int pmd_present(pmd_t pmd)
208 {
209 	/*
210 	 * Checking for _PAGE_LEAF is needed too because:
211 	 * When splitting a THP, split_huge_page() will temporarily clear
212 	 * the present bit, in this situation, pmd_present() and
213 	 * pmd_trans_huge() still needs to return true.
214 	 */
215 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
216 }
217 #else
218 static inline int pmd_present(pmd_t pmd)
219 {
220 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
221 }
222 #endif
223 
224 static inline int pmd_none(pmd_t pmd)
225 {
226 	return (pmd_val(pmd) == 0);
227 }
228 
229 static inline int pmd_bad(pmd_t pmd)
230 {
231 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
232 }
233 
234 #define pmd_leaf	pmd_leaf
235 static inline int pmd_leaf(pmd_t pmd)
236 {
237 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
238 }
239 
240 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
241 {
242 	*pmdp = pmd;
243 }
244 
245 static inline void pmd_clear(pmd_t *pmdp)
246 {
247 	set_pmd(pmdp, __pmd(0));
248 }
249 
250 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
251 {
252 	return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
253 }
254 
255 static inline unsigned long _pgd_pfn(pgd_t pgd)
256 {
257 	return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
258 }
259 
260 static inline struct page *pmd_page(pmd_t pmd)
261 {
262 	return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
263 }
264 
265 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
266 {
267 	return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
268 }
269 
270 static inline pte_t pmd_pte(pmd_t pmd)
271 {
272 	return __pte(pmd_val(pmd));
273 }
274 
275 static inline pte_t pud_pte(pud_t pud)
276 {
277 	return __pte(pud_val(pud));
278 }
279 
280 /* Yields the page frame number (PFN) of a page table entry */
281 static inline unsigned long pte_pfn(pte_t pte)
282 {
283 	return (pte_val(pte) >> _PAGE_PFN_SHIFT);
284 }
285 
286 #define pte_page(x)     pfn_to_page(pte_pfn(x))
287 
288 /* Constructs a page table entry */
289 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
290 {
291 	return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
292 }
293 
294 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
295 
296 static inline int pte_present(pte_t pte)
297 {
298 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
299 }
300 
301 static inline int pte_none(pte_t pte)
302 {
303 	return (pte_val(pte) == 0);
304 }
305 
306 static inline int pte_write(pte_t pte)
307 {
308 	return pte_val(pte) & _PAGE_WRITE;
309 }
310 
311 static inline int pte_exec(pte_t pte)
312 {
313 	return pte_val(pte) & _PAGE_EXEC;
314 }
315 
316 static inline int pte_huge(pte_t pte)
317 {
318 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
319 }
320 
321 static inline int pte_dirty(pte_t pte)
322 {
323 	return pte_val(pte) & _PAGE_DIRTY;
324 }
325 
326 static inline int pte_young(pte_t pte)
327 {
328 	return pte_val(pte) & _PAGE_ACCESSED;
329 }
330 
331 static inline int pte_special(pte_t pte)
332 {
333 	return pte_val(pte) & _PAGE_SPECIAL;
334 }
335 
336 /* static inline pte_t pte_rdprotect(pte_t pte) */
337 
338 static inline pte_t pte_wrprotect(pte_t pte)
339 {
340 	return __pte(pte_val(pte) & ~(_PAGE_WRITE));
341 }
342 
343 /* static inline pte_t pte_mkread(pte_t pte) */
344 
345 static inline pte_t pte_mkwrite(pte_t pte)
346 {
347 	return __pte(pte_val(pte) | _PAGE_WRITE);
348 }
349 
350 /* static inline pte_t pte_mkexec(pte_t pte) */
351 
352 static inline pte_t pte_mkdirty(pte_t pte)
353 {
354 	return __pte(pte_val(pte) | _PAGE_DIRTY);
355 }
356 
357 static inline pte_t pte_mkclean(pte_t pte)
358 {
359 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
360 }
361 
362 static inline pte_t pte_mkyoung(pte_t pte)
363 {
364 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
365 }
366 
367 static inline pte_t pte_mkold(pte_t pte)
368 {
369 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
370 }
371 
372 static inline pte_t pte_mkspecial(pte_t pte)
373 {
374 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
375 }
376 
377 static inline pte_t pte_mkhuge(pte_t pte)
378 {
379 	return pte;
380 }
381 
382 #ifdef CONFIG_NUMA_BALANCING
383 /*
384  * See the comment in include/asm-generic/pgtable.h
385  */
386 static inline int pte_protnone(pte_t pte)
387 {
388 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
389 }
390 
391 static inline int pmd_protnone(pmd_t pmd)
392 {
393 	return pte_protnone(pmd_pte(pmd));
394 }
395 #endif
396 
397 /* Modify page protection bits */
398 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
399 {
400 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
401 }
402 
403 #define pgd_ERROR(e) \
404 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
405 
406 
407 /* Commit new configuration to MMU hardware */
408 static inline void update_mmu_cache(struct vm_area_struct *vma,
409 	unsigned long address, pte_t *ptep)
410 {
411 	/*
412 	 * The kernel assumes that TLBs don't cache invalid entries, but
413 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
414 	 * cache flush; it is necessary even after writing invalid entries.
415 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
416 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
417 	 */
418 	local_flush_tlb_page(address);
419 }
420 
421 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
422 		unsigned long address, pmd_t *pmdp)
423 {
424 	pte_t *ptep = (pte_t *)pmdp;
425 
426 	update_mmu_cache(vma, address, ptep);
427 }
428 
429 #define __HAVE_ARCH_PTE_SAME
430 static inline int pte_same(pte_t pte_a, pte_t pte_b)
431 {
432 	return pte_val(pte_a) == pte_val(pte_b);
433 }
434 
435 /*
436  * Certain architectures need to do special things when PTEs within
437  * a page table are directly modified.  Thus, the following hook is
438  * made available.
439  */
440 static inline void set_pte(pte_t *ptep, pte_t pteval)
441 {
442 	*ptep = pteval;
443 }
444 
445 void flush_icache_pte(pte_t pte);
446 
447 static inline void set_pte_at(struct mm_struct *mm,
448 	unsigned long addr, pte_t *ptep, pte_t pteval)
449 {
450 	if (pte_present(pteval) && pte_exec(pteval))
451 		flush_icache_pte(pteval);
452 
453 	set_pte(ptep, pteval);
454 }
455 
456 static inline void pte_clear(struct mm_struct *mm,
457 	unsigned long addr, pte_t *ptep)
458 {
459 	set_pte_at(mm, addr, ptep, __pte(0));
460 }
461 
462 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
463 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
464 					unsigned long address, pte_t *ptep,
465 					pte_t entry, int dirty)
466 {
467 	if (!pte_same(*ptep, entry))
468 		set_pte_at(vma->vm_mm, address, ptep, entry);
469 	/*
470 	 * update_mmu_cache will unconditionally execute, handling both
471 	 * the case that the PTE changed and the spurious fault case.
472 	 */
473 	return true;
474 }
475 
476 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
477 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
478 				       unsigned long address, pte_t *ptep)
479 {
480 	return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
481 }
482 
483 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
484 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
485 					    unsigned long address,
486 					    pte_t *ptep)
487 {
488 	if (!pte_young(*ptep))
489 		return 0;
490 	return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
491 }
492 
493 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
494 static inline void ptep_set_wrprotect(struct mm_struct *mm,
495 				      unsigned long address, pte_t *ptep)
496 {
497 	atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
498 }
499 
500 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
501 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
502 					 unsigned long address, pte_t *ptep)
503 {
504 	/*
505 	 * This comment is borrowed from x86, but applies equally to RISC-V:
506 	 *
507 	 * Clearing the accessed bit without a TLB flush
508 	 * doesn't cause data corruption. [ It could cause incorrect
509 	 * page aging and the (mistaken) reclaim of hot pages, but the
510 	 * chance of that should be relatively low. ]
511 	 *
512 	 * So as a performance optimization don't flush the TLB when
513 	 * clearing the accessed bit, it will eventually be flushed by
514 	 * a context switch or a VM operation anyway. [ In the rare
515 	 * event of it not getting flushed for a long time the delay
516 	 * shouldn't really matter because there's no real memory
517 	 * pressure for swapout to react to. ]
518 	 */
519 	return ptep_test_and_clear_young(vma, address, ptep);
520 }
521 
522 /*
523  * THP functions
524  */
525 static inline pmd_t pte_pmd(pte_t pte)
526 {
527 	return __pmd(pte_val(pte));
528 }
529 
530 static inline pmd_t pmd_mkhuge(pmd_t pmd)
531 {
532 	return pmd;
533 }
534 
535 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
536 {
537 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
538 }
539 
540 #define __pmd_to_phys(pmd)  (pmd_val(pmd) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
541 
542 static inline unsigned long pmd_pfn(pmd_t pmd)
543 {
544 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
545 }
546 
547 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
548 {
549 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
550 }
551 
552 #define pmd_write pmd_write
553 static inline int pmd_write(pmd_t pmd)
554 {
555 	return pte_write(pmd_pte(pmd));
556 }
557 
558 static inline int pmd_dirty(pmd_t pmd)
559 {
560 	return pte_dirty(pmd_pte(pmd));
561 }
562 
563 static inline int pmd_young(pmd_t pmd)
564 {
565 	return pte_young(pmd_pte(pmd));
566 }
567 
568 static inline pmd_t pmd_mkold(pmd_t pmd)
569 {
570 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
571 }
572 
573 static inline pmd_t pmd_mkyoung(pmd_t pmd)
574 {
575 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
576 }
577 
578 static inline pmd_t pmd_mkwrite(pmd_t pmd)
579 {
580 	return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
581 }
582 
583 static inline pmd_t pmd_wrprotect(pmd_t pmd)
584 {
585 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
586 }
587 
588 static inline pmd_t pmd_mkclean(pmd_t pmd)
589 {
590 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
591 }
592 
593 static inline pmd_t pmd_mkdirty(pmd_t pmd)
594 {
595 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
596 }
597 
598 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
599 				pmd_t *pmdp, pmd_t pmd)
600 {
601 	return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
602 }
603 
604 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
605 				pud_t *pudp, pud_t pud)
606 {
607 	return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
608 }
609 
610 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
611 static inline int pmd_trans_huge(pmd_t pmd)
612 {
613 	return pmd_leaf(pmd);
614 }
615 
616 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
617 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
618 					unsigned long address, pmd_t *pmdp,
619 					pmd_t entry, int dirty)
620 {
621 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
622 }
623 
624 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
625 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
626 					unsigned long address, pmd_t *pmdp)
627 {
628 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
629 }
630 
631 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
632 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
633 					unsigned long address, pmd_t *pmdp)
634 {
635 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
636 }
637 
638 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
639 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
640 					unsigned long address, pmd_t *pmdp)
641 {
642 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
643 }
644 
645 #define pmdp_establish pmdp_establish
646 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
647 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
648 {
649 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
650 }
651 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
652 
653 /*
654  * Encode and decode a swap entry
655  *
656  * Format of swap PTE:
657  *	bit            0:	_PAGE_PRESENT (zero)
658  *	bit       1 to 3:       _PAGE_LEAF (zero)
659  *	bit            5:	_PAGE_PROT_NONE (zero)
660  *	bits      6 to 10:	swap type
661  *	bits 10 to XLEN-1:	swap offset
662  */
663 #define __SWP_TYPE_SHIFT	6
664 #define __SWP_TYPE_BITS		5
665 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
666 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
667 
668 #define MAX_SWAPFILES_CHECK()	\
669 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
670 
671 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
672 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
673 #define __swp_entry(type, offset) ((swp_entry_t) \
674 	{ ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
675 
676 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
677 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
678 
679 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
680 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
681 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
682 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
683 
684 /*
685  * In the RV64 Linux scheme, we give the user half of the virtual-address space
686  * and give the kernel the other (upper) half.
687  */
688 #ifdef CONFIG_64BIT
689 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
690 #else
691 #define KERN_VIRT_START	FIXADDR_START
692 #endif
693 
694 /*
695  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
696  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
697  * Task size is:
698  * -     0x9fc00000 (~2.5GB) for RV32.
699  * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
700  * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
701  *
702  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
703  * Instruction Set Manual Volume II: Privileged Architecture" states that
704  * "load and store effective addresses, which are 64bits, must have bits
705  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
706  */
707 #ifdef CONFIG_64BIT
708 #define TASK_SIZE      (PGDIR_SIZE * PTRS_PER_PGD / 2)
709 #define TASK_SIZE_MIN  (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
710 #else
711 #define TASK_SIZE	FIXADDR_START
712 #define TASK_SIZE_MIN	TASK_SIZE
713 #endif
714 
715 #else /* CONFIG_MMU */
716 
717 #define PAGE_SHARED		__pgprot(0)
718 #define PAGE_KERNEL		__pgprot(0)
719 #define swapper_pg_dir		NULL
720 #define TASK_SIZE		0xffffffffUL
721 #define VMALLOC_START		0
722 #define VMALLOC_END		TASK_SIZE
723 
724 #endif /* !CONFIG_MMU */
725 
726 #define kern_addr_valid(addr)   (1) /* FIXME */
727 
728 extern char _start[];
729 extern void *_dtb_early_va;
730 extern uintptr_t _dtb_early_pa;
731 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
732 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
733 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
734 #else
735 #define dtb_early_va	_dtb_early_va
736 #define dtb_early_pa	_dtb_early_pa
737 #endif /* CONFIG_XIP_KERNEL */
738 extern u64 satp_mode;
739 extern bool pgtable_l4_enabled;
740 
741 void paging_init(void);
742 void misc_mem_init(void);
743 
744 /*
745  * ZERO_PAGE is a global shared page that is always zero,
746  * used for zero-mapped memory areas, etc.
747  */
748 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
749 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
750 
751 #endif /* !__ASSEMBLY__ */
752 
753 #endif /* _ASM_RISCV_PGTABLE_H */
754