xref: /openbmc/linux/arch/riscv/include/asm/pgtable.h (revision 5b4fc395)
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_l5_enabled ? \
67 				57 : (pgtable_l4_enabled ? 48 : 39))
68 #else
69 #define VA_BITS		32
70 #endif
71 
72 #define VMEMMAP_SHIFT \
73 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
74 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
75 #define VMEMMAP_END	VMALLOC_START
76 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
77 
78 /*
79  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
80  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
81  */
82 #define vmemmap		((struct page *)VMEMMAP_START)
83 
84 #define PCI_IO_SIZE      SZ_16M
85 #define PCI_IO_END       VMEMMAP_START
86 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
87 
88 #define FIXADDR_TOP      PCI_IO_START
89 #ifdef CONFIG_64BIT
90 #define FIXADDR_SIZE     PMD_SIZE
91 #else
92 #define FIXADDR_SIZE     PGDIR_SIZE
93 #endif
94 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
95 
96 #endif
97 
98 #ifdef CONFIG_XIP_KERNEL
99 #define XIP_OFFSET		SZ_32M
100 #define XIP_OFFSET_MASK		(SZ_32M - 1)
101 #else
102 #define XIP_OFFSET		0
103 #endif
104 
105 #ifndef __ASSEMBLY__
106 
107 #include <asm/page.h>
108 #include <asm/tlbflush.h>
109 #include <linux/mm_types.h>
110 
111 #define __page_val_to_pfn(_val)  (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
112 
113 #ifdef CONFIG_64BIT
114 #include <asm/pgtable-64.h>
115 #else
116 #include <asm/pgtable-32.h>
117 #endif /* CONFIG_64BIT */
118 
119 #include <linux/page_table_check.h>
120 
121 #ifdef CONFIG_XIP_KERNEL
122 #define XIP_FIXUP(addr) ({							\
123 	uintptr_t __a = (uintptr_t)(addr);					\
124 	(__a >= CONFIG_XIP_PHYS_ADDR && \
125 	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
126 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
127 		__a;								\
128 	})
129 #else
130 #define XIP_FIXUP(addr)		(addr)
131 #endif /* CONFIG_XIP_KERNEL */
132 
133 struct pt_alloc_ops {
134 	pte_t *(*get_pte_virt)(phys_addr_t pa);
135 	phys_addr_t (*alloc_pte)(uintptr_t va);
136 #ifndef __PAGETABLE_PMD_FOLDED
137 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
138 	phys_addr_t (*alloc_pmd)(uintptr_t va);
139 	pud_t *(*get_pud_virt)(phys_addr_t pa);
140 	phys_addr_t (*alloc_pud)(uintptr_t va);
141 	p4d_t *(*get_p4d_virt)(phys_addr_t pa);
142 	phys_addr_t (*alloc_p4d)(uintptr_t va);
143 #endif
144 };
145 
146 extern struct pt_alloc_ops pt_ops __initdata;
147 
148 #ifdef CONFIG_MMU
149 /* Number of PGD entries that a user-mode program can use */
150 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
151 
152 /* Page protection bits */
153 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
154 
155 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
156 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
157 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
158 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
159 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
160 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
161 					 _PAGE_EXEC | _PAGE_WRITE)
162 
163 #define PAGE_COPY		PAGE_READ
164 #define PAGE_COPY_EXEC		PAGE_EXEC
165 #define PAGE_COPY_READ_EXEC	PAGE_READ_EXEC
166 #define PAGE_SHARED		PAGE_WRITE
167 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
168 
169 #define _PAGE_KERNEL		(_PAGE_READ \
170 				| _PAGE_WRITE \
171 				| _PAGE_PRESENT \
172 				| _PAGE_ACCESSED \
173 				| _PAGE_DIRTY \
174 				| _PAGE_GLOBAL)
175 
176 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
177 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
178 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
179 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
180 					 | _PAGE_EXEC)
181 
182 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
183 
184 #define _PAGE_IOREMAP	((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_IO)
185 #define PAGE_KERNEL_IO		__pgprot(_PAGE_IOREMAP)
186 
187 extern pgd_t swapper_pg_dir[];
188 
189 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
190 static inline int pmd_present(pmd_t pmd)
191 {
192 	/*
193 	 * Checking for _PAGE_LEAF is needed too because:
194 	 * When splitting a THP, split_huge_page() will temporarily clear
195 	 * the present bit, in this situation, pmd_present() and
196 	 * pmd_trans_huge() still needs to return true.
197 	 */
198 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
199 }
200 #else
201 static inline int pmd_present(pmd_t pmd)
202 {
203 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
204 }
205 #endif
206 
207 static inline int pmd_none(pmd_t pmd)
208 {
209 	return (pmd_val(pmd) == 0);
210 }
211 
212 static inline int pmd_bad(pmd_t pmd)
213 {
214 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
215 }
216 
217 #define pmd_leaf	pmd_leaf
218 static inline int pmd_leaf(pmd_t pmd)
219 {
220 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
221 }
222 
223 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
224 {
225 	*pmdp = pmd;
226 }
227 
228 static inline void pmd_clear(pmd_t *pmdp)
229 {
230 	set_pmd(pmdp, __pmd(0));
231 }
232 
233 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
234 {
235 	unsigned long prot_val = pgprot_val(prot);
236 
237 	ALT_THEAD_PMA(prot_val);
238 
239 	return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val);
240 }
241 
242 static inline unsigned long _pgd_pfn(pgd_t pgd)
243 {
244 	return __page_val_to_pfn(pgd_val(pgd));
245 }
246 
247 static inline struct page *pmd_page(pmd_t pmd)
248 {
249 	return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
250 }
251 
252 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
253 {
254 	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
255 }
256 
257 static inline pte_t pmd_pte(pmd_t pmd)
258 {
259 	return __pte(pmd_val(pmd));
260 }
261 
262 static inline pte_t pud_pte(pud_t pud)
263 {
264 	return __pte(pud_val(pud));
265 }
266 
267 /* Yields the page frame number (PFN) of a page table entry */
268 static inline unsigned long pte_pfn(pte_t pte)
269 {
270 	return __page_val_to_pfn(pte_val(pte));
271 }
272 
273 #define pte_page(x)     pfn_to_page(pte_pfn(x))
274 
275 /* Constructs a page table entry */
276 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
277 {
278 	unsigned long prot_val = pgprot_val(prot);
279 
280 	ALT_THEAD_PMA(prot_val);
281 
282 	return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val);
283 }
284 
285 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
286 
287 static inline int pte_present(pte_t pte)
288 {
289 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
290 }
291 
292 static inline int pte_none(pte_t pte)
293 {
294 	return (pte_val(pte) == 0);
295 }
296 
297 static inline int pte_write(pte_t pte)
298 {
299 	return pte_val(pte) & _PAGE_WRITE;
300 }
301 
302 static inline int pte_exec(pte_t pte)
303 {
304 	return pte_val(pte) & _PAGE_EXEC;
305 }
306 
307 static inline int pte_user(pte_t pte)
308 {
309 	return pte_val(pte) & _PAGE_USER;
310 }
311 
312 static inline int pte_huge(pte_t pte)
313 {
314 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
315 }
316 
317 static inline int pte_dirty(pte_t pte)
318 {
319 	return pte_val(pte) & _PAGE_DIRTY;
320 }
321 
322 static inline int pte_young(pte_t pte)
323 {
324 	return pte_val(pte) & _PAGE_ACCESSED;
325 }
326 
327 static inline int pte_special(pte_t pte)
328 {
329 	return pte_val(pte) & _PAGE_SPECIAL;
330 }
331 
332 /* static inline pte_t pte_rdprotect(pte_t pte) */
333 
334 static inline pte_t pte_wrprotect(pte_t pte)
335 {
336 	return __pte(pte_val(pte) & ~(_PAGE_WRITE));
337 }
338 
339 /* static inline pte_t pte_mkread(pte_t pte) */
340 
341 static inline pte_t pte_mkwrite(pte_t pte)
342 {
343 	return __pte(pte_val(pte) | _PAGE_WRITE);
344 }
345 
346 /* static inline pte_t pte_mkexec(pte_t pte) */
347 
348 static inline pte_t pte_mkdirty(pte_t pte)
349 {
350 	return __pte(pte_val(pte) | _PAGE_DIRTY);
351 }
352 
353 static inline pte_t pte_mkclean(pte_t pte)
354 {
355 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
356 }
357 
358 static inline pte_t pte_mkyoung(pte_t pte)
359 {
360 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
361 }
362 
363 static inline pte_t pte_mkold(pte_t pte)
364 {
365 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
366 }
367 
368 static inline pte_t pte_mkspecial(pte_t pte)
369 {
370 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
371 }
372 
373 static inline pte_t pte_mkhuge(pte_t pte)
374 {
375 	return pte;
376 }
377 
378 #ifdef CONFIG_NUMA_BALANCING
379 /*
380  * See the comment in include/asm-generic/pgtable.h
381  */
382 static inline int pte_protnone(pte_t pte)
383 {
384 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
385 }
386 
387 static inline int pmd_protnone(pmd_t pmd)
388 {
389 	return pte_protnone(pmd_pte(pmd));
390 }
391 #endif
392 
393 /* Modify page protection bits */
394 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
395 {
396 	unsigned long newprot_val = pgprot_val(newprot);
397 
398 	ALT_THEAD_PMA(newprot_val);
399 
400 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val);
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 set_pte_at(struct mm_struct *mm,
457 	unsigned long addr, pte_t *ptep, pte_t pteval)
458 {
459 	page_table_check_pte_set(mm, addr, ptep, pteval);
460 	__set_pte_at(mm, addr, ptep, pteval);
461 }
462 
463 static inline void pte_clear(struct mm_struct *mm,
464 	unsigned long addr, pte_t *ptep)
465 {
466 	__set_pte_at(mm, addr, ptep, __pte(0));
467 }
468 
469 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
470 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
471 					unsigned long address, pte_t *ptep,
472 					pte_t entry, int dirty)
473 {
474 	if (!pte_same(*ptep, entry))
475 		set_pte_at(vma->vm_mm, address, ptep, entry);
476 	/*
477 	 * update_mmu_cache will unconditionally execute, handling both
478 	 * the case that the PTE changed and the spurious fault case.
479 	 */
480 	return true;
481 }
482 
483 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
484 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
485 				       unsigned long address, pte_t *ptep)
486 {
487 	pte_t pte = __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
488 
489 	page_table_check_pte_clear(mm, address, pte);
490 
491 	return pte;
492 }
493 
494 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
495 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
496 					    unsigned long address,
497 					    pte_t *ptep)
498 {
499 	if (!pte_young(*ptep))
500 		return 0;
501 	return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
502 }
503 
504 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
505 static inline void ptep_set_wrprotect(struct mm_struct *mm,
506 				      unsigned long address, pte_t *ptep)
507 {
508 	atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
509 }
510 
511 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
512 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
513 					 unsigned long address, pte_t *ptep)
514 {
515 	/*
516 	 * This comment is borrowed from x86, but applies equally to RISC-V:
517 	 *
518 	 * Clearing the accessed bit without a TLB flush
519 	 * doesn't cause data corruption. [ It could cause incorrect
520 	 * page aging and the (mistaken) reclaim of hot pages, but the
521 	 * chance of that should be relatively low. ]
522 	 *
523 	 * So as a performance optimization don't flush the TLB when
524 	 * clearing the accessed bit, it will eventually be flushed by
525 	 * a context switch or a VM operation anyway. [ In the rare
526 	 * event of it not getting flushed for a long time the delay
527 	 * shouldn't really matter because there's no real memory
528 	 * pressure for swapout to react to. ]
529 	 */
530 	return ptep_test_and_clear_young(vma, address, ptep);
531 }
532 
533 #define pgprot_noncached pgprot_noncached
534 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
535 {
536 	unsigned long prot = pgprot_val(_prot);
537 
538 	prot &= ~_PAGE_MTMASK;
539 	prot |= _PAGE_IO;
540 
541 	return __pgprot(prot);
542 }
543 
544 #define pgprot_writecombine pgprot_writecombine
545 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
546 {
547 	unsigned long prot = pgprot_val(_prot);
548 
549 	prot &= ~_PAGE_MTMASK;
550 	prot |= _PAGE_NOCACHE;
551 
552 	return __pgprot(prot);
553 }
554 
555 /*
556  * THP functions
557  */
558 static inline pmd_t pte_pmd(pte_t pte)
559 {
560 	return __pmd(pte_val(pte));
561 }
562 
563 static inline pmd_t pmd_mkhuge(pmd_t pmd)
564 {
565 	return pmd;
566 }
567 
568 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
569 {
570 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
571 }
572 
573 #define __pmd_to_phys(pmd)  (__page_val_to_pfn(pmd_val(pmd)) << PAGE_SHIFT)
574 
575 static inline unsigned long pmd_pfn(pmd_t pmd)
576 {
577 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
578 }
579 
580 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
581 
582 static inline unsigned long pud_pfn(pud_t pud)
583 {
584 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
585 }
586 
587 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
588 {
589 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
590 }
591 
592 #define pmd_write pmd_write
593 static inline int pmd_write(pmd_t pmd)
594 {
595 	return pte_write(pmd_pte(pmd));
596 }
597 
598 static inline int pmd_dirty(pmd_t pmd)
599 {
600 	return pte_dirty(pmd_pte(pmd));
601 }
602 
603 static inline int pmd_young(pmd_t pmd)
604 {
605 	return pte_young(pmd_pte(pmd));
606 }
607 
608 static inline int pmd_user(pmd_t pmd)
609 {
610 	return pte_user(pmd_pte(pmd));
611 }
612 
613 static inline pmd_t pmd_mkold(pmd_t pmd)
614 {
615 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
616 }
617 
618 static inline pmd_t pmd_mkyoung(pmd_t pmd)
619 {
620 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
621 }
622 
623 static inline pmd_t pmd_mkwrite(pmd_t pmd)
624 {
625 	return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
626 }
627 
628 static inline pmd_t pmd_wrprotect(pmd_t pmd)
629 {
630 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
631 }
632 
633 static inline pmd_t pmd_mkclean(pmd_t pmd)
634 {
635 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
636 }
637 
638 static inline pmd_t pmd_mkdirty(pmd_t pmd)
639 {
640 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
641 }
642 
643 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
644 				pmd_t *pmdp, pmd_t pmd)
645 {
646 	page_table_check_pmd_set(mm, addr, pmdp, pmd);
647 	return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
648 }
649 
650 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
651 				pud_t *pudp, pud_t pud)
652 {
653 	page_table_check_pud_set(mm, addr, pudp, pud);
654 	return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
655 }
656 
657 #ifdef CONFIG_PAGE_TABLE_CHECK
658 static inline bool pte_user_accessible_page(pte_t pte)
659 {
660 	return pte_present(pte) && pte_user(pte);
661 }
662 
663 static inline bool pmd_user_accessible_page(pmd_t pmd)
664 {
665 	return pmd_leaf(pmd) && pmd_user(pmd);
666 }
667 
668 static inline bool pud_user_accessible_page(pud_t pud)
669 {
670 	return pud_leaf(pud) && pud_user(pud);
671 }
672 #endif
673 
674 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
675 static inline int pmd_trans_huge(pmd_t pmd)
676 {
677 	return pmd_leaf(pmd);
678 }
679 
680 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
681 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
682 					unsigned long address, pmd_t *pmdp,
683 					pmd_t entry, int dirty)
684 {
685 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
686 }
687 
688 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
689 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
690 					unsigned long address, pmd_t *pmdp)
691 {
692 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
693 }
694 
695 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
696 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
697 					unsigned long address, pmd_t *pmdp)
698 {
699 	pmd_t pmd = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0));
700 
701 	page_table_check_pmd_clear(mm, address, pmd);
702 
703 	return pmd;
704 }
705 
706 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
707 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
708 					unsigned long address, pmd_t *pmdp)
709 {
710 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
711 }
712 
713 #define pmdp_establish pmdp_establish
714 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
715 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
716 {
717 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
718 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
719 }
720 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
721 
722 /*
723  * Encode and decode a swap entry
724  *
725  * Format of swap PTE:
726  *	bit            0:	_PAGE_PRESENT (zero)
727  *	bit       1 to 3:       _PAGE_LEAF (zero)
728  *	bit            5:	_PAGE_PROT_NONE (zero)
729  *	bits      6 to 10:	swap type
730  *	bits 10 to XLEN-1:	swap offset
731  */
732 #define __SWP_TYPE_SHIFT	6
733 #define __SWP_TYPE_BITS		5
734 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
735 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
736 
737 #define MAX_SWAPFILES_CHECK()	\
738 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
739 
740 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
741 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
742 #define __swp_entry(type, offset) ((swp_entry_t) \
743 	{ ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
744 
745 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
746 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
747 
748 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
749 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
750 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
751 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
752 
753 /*
754  * In the RV64 Linux scheme, we give the user half of the virtual-address space
755  * and give the kernel the other (upper) half.
756  */
757 #ifdef CONFIG_64BIT
758 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
759 #else
760 #define KERN_VIRT_START	FIXADDR_START
761 #endif
762 
763 /*
764  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
765  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
766  * Task size is:
767  * -     0x9fc00000 (~2.5GB) for RV32.
768  * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
769  * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
770  *
771  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
772  * Instruction Set Manual Volume II: Privileged Architecture" states that
773  * "load and store effective addresses, which are 64bits, must have bits
774  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
775  */
776 #ifdef CONFIG_64BIT
777 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
778 #define TASK_SIZE_MIN	(PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
779 
780 #ifdef CONFIG_COMPAT
781 #define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
782 #define TASK_SIZE	(test_thread_flag(TIF_32BIT) ? \
783 			 TASK_SIZE_32 : TASK_SIZE_64)
784 #else
785 #define TASK_SIZE	TASK_SIZE_64
786 #endif
787 
788 #else
789 #define TASK_SIZE	FIXADDR_START
790 #define TASK_SIZE_MIN	TASK_SIZE
791 #endif
792 
793 #else /* CONFIG_MMU */
794 
795 #define PAGE_SHARED		__pgprot(0)
796 #define PAGE_KERNEL		__pgprot(0)
797 #define swapper_pg_dir		NULL
798 #define TASK_SIZE		0xffffffffUL
799 #define VMALLOC_START		0
800 #define VMALLOC_END		TASK_SIZE
801 
802 #endif /* !CONFIG_MMU */
803 
804 #define kern_addr_valid(addr)   (1) /* FIXME */
805 
806 extern char _start[];
807 extern void *_dtb_early_va;
808 extern uintptr_t _dtb_early_pa;
809 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
810 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
811 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
812 #else
813 #define dtb_early_va	_dtb_early_va
814 #define dtb_early_pa	_dtb_early_pa
815 #endif /* CONFIG_XIP_KERNEL */
816 extern u64 satp_mode;
817 extern bool pgtable_l4_enabled;
818 
819 void paging_init(void);
820 void misc_mem_init(void);
821 
822 /*
823  * ZERO_PAGE is a global shared page that is always zero,
824  * used for zero-mapped memory areas, etc.
825  */
826 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
827 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
828 
829 #endif /* !__ASSEMBLY__ */
830 
831 #endif /* _ASM_RISCV_PGTABLE_H */
832