xref: /linux/arch/riscv/include/asm/pgtable.h (revision d639d9fa162aadec1ae9980c4dcf6e50bd2f8290)
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 #ifdef CONFIG_RELOCATABLE
16 #define KERNEL_LINK_ADDR	UL(0)
17 #else
18 #define KERNEL_LINK_ADDR	_AC(CONFIG_PHYS_RAM_BASE, UL)
19 #endif
20 #define KERN_VIRT_SIZE		(UL(-1))
21 #else
22 
23 #define ADDRESS_SPACE_END	(UL(-1))
24 
25 #ifdef CONFIG_64BIT
26 /* Leave 2GB for kernel and BPF at the end of the address space */
27 #define KERNEL_LINK_ADDR	(ADDRESS_SPACE_END - SZ_2G + 1)
28 #else
29 #define KERNEL_LINK_ADDR	PAGE_OFFSET
30 #endif
31 
32 /* Number of entries in the page global directory */
33 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
34 /* Number of entries in the page table */
35 #define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
36 
37 /*
38  * Half of the kernel address space (1/4 of the entries of the page global
39  * directory) is for the direct mapping.
40  */
41 #define KERN_VIRT_SIZE          ((PTRS_PER_PGD / 2 * PGDIR_SIZE) / 2)
42 
43 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
44 #define VMALLOC_END      PAGE_OFFSET
45 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
46 
47 #define BPF_JIT_REGION_SIZE	(SZ_128M)
48 #ifdef CONFIG_64BIT
49 #define BPF_JIT_REGION_START	(BPF_JIT_REGION_END - BPF_JIT_REGION_SIZE)
50 #define BPF_JIT_REGION_END	(MODULES_END)
51 #else
52 #define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
53 #define BPF_JIT_REGION_END	(VMALLOC_END)
54 #endif
55 
56 /* Modules always live before the kernel */
57 #ifdef CONFIG_64BIT
58 /* This is used to define the end of the KASAN shadow region */
59 #define MODULES_LOWEST_VADDR	(KERNEL_LINK_ADDR - SZ_2G)
60 #define MODULES_VADDR		(PFN_ALIGN((unsigned long)&_end) - SZ_2G)
61 #define MODULES_END		(PFN_ALIGN((unsigned long)&_start))
62 #else
63 #define MODULES_VADDR		VMALLOC_START
64 #define MODULES_END		VMALLOC_END
65 #endif
66 
67 /*
68  * Roughly size the vmemmap space to be large enough to fit enough
69  * struct pages to map half the virtual address space. Then
70  * position vmemmap directly below the VMALLOC region.
71  */
72 #define VA_BITS_SV32 32
73 #ifdef CONFIG_64BIT
74 #define VA_BITS_SV39 39
75 #define VA_BITS_SV48 48
76 #define VA_BITS_SV57 57
77 
78 #define VA_BITS		(pgtable_l5_enabled ? \
79 				VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39))
80 #else
81 #define VA_BITS		VA_BITS_SV32
82 #endif
83 
84 #define VMEMMAP_SHIFT \
85 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
86 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
87 #define VMEMMAP_END	VMALLOC_START
88 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
89 
90 /*
91  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
92  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
93  */
94 #define vmemmap		((struct page *)VMEMMAP_START - vmemmap_start_pfn)
95 
96 /* Needed to limit get_free_mem_region() */
97 #if defined(CONFIG_FLATMEM)
98 #define DIRECT_MAP_PHYSMEM_END (phys_ram_base + KERN_VIRT_SIZE - 1)
99 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
100 #define DIRECT_MAP_PHYSMEM_END \
101 	((vmemmap_start_pfn + VMEMMAP_SIZE / sizeof(struct page)) * PAGE_SIZE - 1)
102 #elif defined(CONFIG_SPARSEMEM)
103 /* DIRECT_MAP_PHYSMEM_END is not limited by VA space assignment in this case */
104 #endif
105 
106 #define PCI_IO_SIZE      SZ_16M
107 #define PCI_IO_END       VMEMMAP_START
108 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
109 
110 #define FIXADDR_TOP      PCI_IO_START
111 #ifdef CONFIG_64BIT
112 #define MAX_FDT_SIZE	 PMD_SIZE
113 #define FIX_FDT_SIZE	 (MAX_FDT_SIZE + SZ_2M)
114 #define FIXADDR_SIZE     (PMD_SIZE + FIX_FDT_SIZE)
115 #else
116 #define MAX_FDT_SIZE	 PGDIR_SIZE
117 #define FIX_FDT_SIZE	 MAX_FDT_SIZE
118 #define FIXADDR_SIZE     (PGDIR_SIZE + FIX_FDT_SIZE)
119 #endif
120 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
121 
122 #endif
123 
124 #ifndef __ASSEMBLER__
125 
126 #include <asm/page.h>
127 #include <asm/tlbflush.h>
128 #include <linux/mm_types.h>
129 #include <asm/compat.h>
130 #include <asm/cpufeature.h>
131 
132 #define __page_val_to_pfn(_val)  (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
133 
134 #ifdef CONFIG_64BIT
135 #include <asm/pgtable-64.h>
136 
137 #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
138 #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
139 #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
140 #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
141 #else
142 #include <asm/pgtable-32.h>
143 #endif /* CONFIG_64BIT */
144 
145 #include <linux/page_table_check.h>
146 
147 struct pt_alloc_ops {
148 	pte_t *(*get_pte_virt)(phys_addr_t pa);
149 	phys_addr_t (*alloc_pte)(uintptr_t va);
150 #ifndef __PAGETABLE_PMD_FOLDED
151 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
152 	phys_addr_t (*alloc_pmd)(uintptr_t va);
153 	pud_t *(*get_pud_virt)(phys_addr_t pa);
154 	phys_addr_t (*alloc_pud)(uintptr_t va);
155 	p4d_t *(*get_p4d_virt)(phys_addr_t pa);
156 	phys_addr_t (*alloc_p4d)(uintptr_t va);
157 #endif
158 };
159 
160 extern struct pt_alloc_ops pt_ops __meminitdata;
161 
162 #ifdef CONFIG_MMU
163 /* Number of PGD entries that a user-mode program can use */
164 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
165 
166 /* Page protection bits */
167 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
168 
169 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
170 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
171 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
172 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
173 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
174 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
175 					 _PAGE_EXEC | _PAGE_WRITE)
176 #define PAGE_SHADOWSTACK       __pgprot(_PAGE_BASE | _PAGE_WRITE)
177 
178 #define PAGE_COPY		PAGE_READ
179 #define PAGE_COPY_EXEC		PAGE_READ_EXEC
180 #define PAGE_SHARED		PAGE_WRITE
181 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
182 
183 #define _PAGE_KERNEL		(_PAGE_READ \
184 				| _PAGE_WRITE \
185 				| _PAGE_PRESENT \
186 				| _PAGE_ACCESSED \
187 				| _PAGE_DIRTY \
188 				| _PAGE_GLOBAL)
189 
190 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
191 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
192 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
193 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
194 					 | _PAGE_EXEC)
195 
196 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
197 
198 #define _PAGE_KERNEL_NC ((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_NOCACHE)
199 #define _PAGE_IOREMAP	((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_IO)
200 #define PAGE_KERNEL_IO		__pgprot(_PAGE_IOREMAP)
201 
202 extern pgd_t swapper_pg_dir[];
203 extern pgd_t trampoline_pg_dir[];
204 extern pgd_t early_pg_dir[];
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 bool 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 	WRITE_ONCE(*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 	unsigned long prot_val = pgprot_val(prot);
253 
254 	ALT_THEAD_PMA(prot_val);
255 
256 	return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val);
257 }
258 
259 static inline unsigned long _pgd_pfn(pgd_t pgd)
260 {
261 	return __page_val_to_pfn(pgd_val(pgd));
262 }
263 
264 static inline struct page *pmd_page(pmd_t pmd)
265 {
266 	return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
267 }
268 
269 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
270 {
271 	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
272 }
273 
274 static inline pte_t pmd_pte(pmd_t pmd)
275 {
276 	return __pte(pmd_val(pmd));
277 }
278 
279 static inline pte_t pud_pte(pud_t pud)
280 {
281 	return __pte(pud_val(pud));
282 }
283 
284 #ifdef CONFIG_RISCV_ISA_SVNAPOT
285 
286 static __always_inline bool has_svnapot(void)
287 {
288 	return riscv_has_extension_likely(RISCV_ISA_EXT_SVNAPOT);
289 }
290 
291 static inline unsigned long pte_napot(pte_t pte)
292 {
293 	return pte_val(pte) & _PAGE_NAPOT;
294 }
295 
296 static inline pte_t pte_mknapot(pte_t pte, unsigned int order)
297 {
298 	int pos = order - 1 + _PAGE_PFN_SHIFT;
299 	unsigned long napot_bit = BIT(pos);
300 	unsigned long napot_mask = ~GENMASK(pos, _PAGE_PFN_SHIFT);
301 
302 	return __pte((pte_val(pte) & napot_mask) | napot_bit | _PAGE_NAPOT);
303 }
304 
305 #else
306 
307 static __always_inline bool has_svnapot(void) { return false; }
308 
309 static inline unsigned long pte_napot(pte_t pte)
310 {
311 	return 0;
312 }
313 
314 #endif /* CONFIG_RISCV_ISA_SVNAPOT */
315 
316 /* Yields the page frame number (PFN) of a page table entry */
317 static inline unsigned long pte_pfn(pte_t pte)
318 {
319 	unsigned long res  = __page_val_to_pfn(pte_val(pte));
320 
321 	if (has_svnapot() && pte_napot(pte))
322 		res = res & (res - 1UL);
323 
324 	return res;
325 }
326 
327 #define pte_page(x)     pfn_to_page(pte_pfn(x))
328 
329 /* Constructs a page table entry */
330 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
331 {
332 	unsigned long prot_val = pgprot_val(prot);
333 
334 	ALT_THEAD_PMA(prot_val);
335 
336 	return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val);
337 }
338 
339 #define pte_pgprot pte_pgprot
340 static inline pgprot_t pte_pgprot(pte_t pte)
341 {
342 	unsigned long pfn = pte_pfn(pte);
343 
344 	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
345 }
346 
347 static inline int pte_present(pte_t pte)
348 {
349 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
350 }
351 
352 #define pte_accessible pte_accessible
353 static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
354 {
355 	if (pte_val(a) & _PAGE_PRESENT)
356 		return true;
357 
358 	if ((pte_val(a) & _PAGE_PROT_NONE) &&
359 	    atomic_read(&mm->tlb_flush_pending))
360 		return true;
361 
362 	return false;
363 }
364 
365 static inline int pte_none(pte_t pte)
366 {
367 	return (pte_val(pte) == 0);
368 }
369 
370 static inline int pte_write(pte_t pte)
371 {
372 	return pte_val(pte) & _PAGE_WRITE;
373 }
374 
375 static inline int pte_exec(pte_t pte)
376 {
377 	return pte_val(pte) & _PAGE_EXEC;
378 }
379 
380 static inline int pte_user(pte_t pte)
381 {
382 	return pte_val(pte) & _PAGE_USER;
383 }
384 
385 static inline int pte_huge(pte_t pte)
386 {
387 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
388 }
389 
390 static inline int pte_dirty(pte_t pte)
391 {
392 	return pte_val(pte) & _PAGE_DIRTY;
393 }
394 
395 static inline int pte_young(pte_t pte)
396 {
397 	return pte_val(pte) & _PAGE_ACCESSED;
398 }
399 
400 static inline int pte_special(pte_t pte)
401 {
402 	return pte_val(pte) & _PAGE_SPECIAL;
403 }
404 
405 /* static inline pte_t pte_rdprotect(pte_t pte) */
406 
407 static inline pte_t pte_wrprotect(pte_t pte)
408 {
409 	return __pte((pte_val(pte) & ~(_PAGE_WRITE)) | (_PAGE_READ));
410 }
411 
412 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
413 #define pgtable_supports_uffd_wp()	\
414 	riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)
415 
416 static inline bool pte_uffd_wp(pte_t pte)
417 {
418 	return !!(pte_val(pte) & _PAGE_UFFD_WP);
419 }
420 
421 static inline pte_t pte_mkuffd_wp(pte_t pte)
422 {
423 	return pte_wrprotect(__pte(pte_val(pte) | _PAGE_UFFD_WP));
424 }
425 
426 static inline pte_t pte_clear_uffd_wp(pte_t pte)
427 {
428 	return __pte(pte_val(pte) & ~(_PAGE_UFFD_WP));
429 }
430 
431 static inline bool pte_swp_uffd_wp(pte_t pte)
432 {
433 	return !!(pte_val(pte) & _PAGE_SWP_UFFD_WP);
434 }
435 
436 static inline pte_t pte_swp_mkuffd_wp(pte_t pte)
437 {
438 	return __pte(pte_val(pte) | _PAGE_SWP_UFFD_WP);
439 }
440 
441 static inline pte_t pte_swp_clear_uffd_wp(pte_t pte)
442 {
443 	return __pte(pte_val(pte) & ~(_PAGE_SWP_UFFD_WP));
444 }
445 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
446 
447 /* static inline pte_t pte_mkread(pte_t pte) */
448 
449 struct vm_area_struct;
450 pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma);
451 #define pte_mkwrite pte_mkwrite
452 
453 static inline pte_t pte_mkwrite_novma(pte_t pte)
454 {
455 	return __pte(pte_val(pte) | _PAGE_WRITE);
456 }
457 
458 static inline pte_t pte_mkwrite_shstk(pte_t pte)
459 {
460 	return __pte((pte_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
461 }
462 
463 /* static inline pte_t pte_mkexec(pte_t pte) */
464 
465 static inline pte_t pte_mkdirty(pte_t pte)
466 {
467 	return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
468 }
469 
470 static inline pte_t pte_mkclean(pte_t pte)
471 {
472 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
473 }
474 
475 static inline pte_t pte_mkyoung(pte_t pte)
476 {
477 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
478 }
479 
480 static inline pte_t pte_mkold(pte_t pte)
481 {
482 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
483 }
484 
485 static inline pte_t pte_mkspecial(pte_t pte)
486 {
487 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
488 }
489 
490 static inline pte_t pte_mkhuge(pte_t pte)
491 {
492 	return pte;
493 }
494 
495 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
496 #define pgtable_supports_soft_dirty()				\
497 	(IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) &&			\
498 	 riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B))
499 
500 static inline bool pte_soft_dirty(pte_t pte)
501 {
502 	return !!(pte_val(pte) & _PAGE_SOFT_DIRTY);
503 }
504 
505 static inline pte_t pte_mksoft_dirty(pte_t pte)
506 {
507 	return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY);
508 }
509 
510 static inline pte_t pte_clear_soft_dirty(pte_t pte)
511 {
512 	return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY));
513 }
514 
515 static inline bool pte_swp_soft_dirty(pte_t pte)
516 {
517 	return !!(pte_val(pte) & _PAGE_SWP_SOFT_DIRTY);
518 }
519 
520 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
521 {
522 	return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY);
523 }
524 
525 static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
526 {
527 	return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY));
528 }
529 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
530 
531 #ifdef CONFIG_RISCV_ISA_SVNAPOT
532 #define pte_leaf_size(pte)	(pte_napot(pte) ?				\
533 					napot_cont_size(napot_cont_order(pte)) :\
534 					PAGE_SIZE)
535 #endif
536 
537 #ifdef CONFIG_NUMA_BALANCING
538 /*
539  * See the comment in include/asm-generic/pgtable.h
540  */
541 static inline int pte_protnone(pte_t pte)
542 {
543 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
544 }
545 
546 static inline int pmd_protnone(pmd_t pmd)
547 {
548 	return pte_protnone(pmd_pte(pmd));
549 }
550 #endif
551 
552 /* Modify page protection bits */
553 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
554 {
555 	unsigned long newprot_val = pgprot_val(newprot);
556 
557 	ALT_THEAD_PMA(newprot_val);
558 
559 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val);
560 }
561 
562 #define pgd_ERROR(e) \
563 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
564 
565 
566 /* Commit new configuration to MMU hardware */
567 static inline void update_mmu_cache_range(struct vm_fault *vmf,
568 		struct vm_area_struct *vma, unsigned long address,
569 		pte_t *ptep, unsigned int nr)
570 {
571 	/*
572 	 * Svvptc guarantees that the new valid pte will be visible within
573 	 * a bounded timeframe, so when the uarch does not cache invalid
574 	 * entries, we don't have to do anything.
575 	 */
576 	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SVVPTC))
577 		return;
578 
579 	/*
580 	 * The kernel assumes that TLBs don't cache invalid entries, but
581 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
582 	 * cache flush; it is necessary even after writing invalid entries.
583 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
584 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
585 	 */
586 	while (nr--)
587 		local_flush_tlb_page(address + nr * PAGE_SIZE);
588 
589 }
590 #define update_mmu_cache(vma, addr, ptep) \
591 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
592 
593 #define update_mmu_tlb_range(vma, addr, ptep, nr) \
594 	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
595 
596 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
597 		unsigned long address, pmd_t *pmdp)
598 {
599 	pte_t *ptep = (pte_t *)pmdp;
600 
601 	update_mmu_cache(vma, address, ptep);
602 }
603 
604 #define __HAVE_ARCH_PTE_SAME
605 static inline int pte_same(pte_t pte_a, pte_t pte_b)
606 {
607 	return pte_val(pte_a) == pte_val(pte_b);
608 }
609 
610 /*
611  * Certain architectures need to do special things when PTEs within
612  * a page table are directly modified.  Thus, the following hook is
613  * made available.
614  */
615 static inline void set_pte(pte_t *ptep, pte_t pteval)
616 {
617 	WRITE_ONCE(*ptep, pteval);
618 }
619 
620 void flush_icache_pte(struct mm_struct *mm, pte_t pte);
621 
622 static inline void __set_pte_at(struct mm_struct *mm, pte_t *ptep, pte_t pteval)
623 {
624 	if (pte_present(pteval) && pte_exec(pteval))
625 		flush_icache_pte(mm, pteval);
626 
627 	set_pte(ptep, pteval);
628 }
629 
630 #define PFN_PTE_SHIFT		_PAGE_PFN_SHIFT
631 
632 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
633 		pte_t *ptep, pte_t pteval, unsigned int nr)
634 {
635 	page_table_check_ptes_set(mm, addr, ptep, pteval, nr);
636 
637 	for (;;) {
638 		__set_pte_at(mm, ptep, pteval);
639 		if (--nr == 0)
640 			break;
641 		ptep++;
642 		pte_val(pteval) += 1 << _PAGE_PFN_SHIFT;
643 	}
644 }
645 #define set_ptes set_ptes
646 
647 static inline void pte_clear(struct mm_struct *mm,
648 	unsigned long addr, pte_t *ptep)
649 {
650 	__set_pte_at(mm, ptep, __pte(0));
651 }
652 
653 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS	/* defined in mm/pgtable.c */
654 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
655 				 pte_t *ptep, pte_t entry, int dirty);
656 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG	/* defined in mm/pgtable.c */
657 bool ptep_test_and_clear_young(struct vm_area_struct *vma,
658 		unsigned long address, pte_t *ptep);
659 
660 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
661 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
662 				       unsigned long address, pte_t *ptep)
663 {
664 #ifdef CONFIG_SMP
665 	pte_t pte = __pte(xchg(&ptep->pte, 0));
666 #else
667 	pte_t pte = *ptep;
668 
669 	set_pte(ptep, __pte(0));
670 #endif
671 
672 	page_table_check_pte_clear(mm, address, pte);
673 
674 	return pte;
675 }
676 
677 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
678 static inline void ptep_set_wrprotect(struct mm_struct *mm,
679 				      unsigned long address, pte_t *ptep)
680 {
681 	pte_t read_pte = READ_ONCE(*ptep);
682 	/*
683 	 * ptep_set_wrprotect can be called for shadow stack ranges too.
684 	 * shadow stack memory is XWR = 010 and thus clearing _PAGE_WRITE will lead to
685 	 * encoding 000b which is wrong encoding with V = 1. This should lead to page fault
686 	 * but we dont want this wrong configuration to be set in page tables.
687 	 */
688 	atomic_long_set((atomic_long_t *)ptep,
689 			((pte_val(read_pte) & ~(unsigned long)_PAGE_WRITE) | _PAGE_READ));
690 }
691 
692 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
693 static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
694 		unsigned long address, pte_t *ptep)
695 {
696 	/*
697 	 * This comment is borrowed from x86, but applies equally to RISC-V:
698 	 *
699 	 * Clearing the accessed bit without a TLB flush
700 	 * doesn't cause data corruption. [ It could cause incorrect
701 	 * page aging and the (mistaken) reclaim of hot pages, but the
702 	 * chance of that should be relatively low. ]
703 	 *
704 	 * So as a performance optimization don't flush the TLB when
705 	 * clearing the accessed bit, it will eventually be flushed by
706 	 * a context switch or a VM operation anyway. [ In the rare
707 	 * event of it not getting flushed for a long time the delay
708 	 * shouldn't really matter because there's no real memory
709 	 * pressure for swapout to react to. ]
710 	 */
711 	return ptep_test_and_clear_young(vma, address, ptep);
712 }
713 
714 #define pgprot_nx pgprot_nx
715 static inline pgprot_t pgprot_nx(pgprot_t _prot)
716 {
717 	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
718 }
719 
720 #define pgprot_noncached pgprot_noncached
721 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
722 {
723 	unsigned long prot = pgprot_val(_prot);
724 
725 	prot &= ~_PAGE_MTMASK;
726 	prot |= _PAGE_IO;
727 
728 	return __pgprot(prot);
729 }
730 
731 #define pgprot_writecombine pgprot_writecombine
732 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
733 {
734 	unsigned long prot = pgprot_val(_prot);
735 
736 	prot &= ~_PAGE_MTMASK;
737 	prot |= _PAGE_NOCACHE;
738 
739 	return __pgprot(prot);
740 }
741 
742 #define pgprot_dmacoherent pgprot_writecombine
743 
744 /*
745  * Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By
746  * default the M-mode firmware enables the hardware updating scheme when only Svadu is present in
747  * DT.
748  */
749 #define arch_has_hw_pte_young arch_has_hw_pte_young
750 static inline bool arch_has_hw_pte_young(void)
751 {
752 	return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
753 }
754 
755 /*
756  * THP functions
757  */
758 static inline pmd_t pte_pmd(pte_t pte)
759 {
760 	return __pmd(pte_val(pte));
761 }
762 
763 static inline pud_t pte_pud(pte_t pte)
764 {
765 	return __pud(pte_val(pte));
766 }
767 
768 static inline pmd_t pmd_mkhuge(pmd_t pmd)
769 {
770 	return pmd;
771 }
772 
773 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
774 {
775 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
776 }
777 
778 #define __pmd_to_phys(pmd)  (__page_val_to_pfn(pmd_val(pmd)) << PAGE_SHIFT)
779 
780 static inline unsigned long pmd_pfn(pmd_t pmd)
781 {
782 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
783 }
784 
785 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
786 
787 #define pud_pfn pud_pfn
788 static inline unsigned long pud_pfn(pud_t pud)
789 {
790 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
791 }
792 
793 #define pmd_pgprot pmd_pgprot
794 static inline pgprot_t pmd_pgprot(pmd_t pmd)
795 {
796 	return pte_pgprot(pmd_pte(pmd));
797 }
798 
799 #define pud_pgprot pud_pgprot
800 static inline pgprot_t pud_pgprot(pud_t pud)
801 {
802 	return pte_pgprot(pud_pte(pud));
803 }
804 
805 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
806 {
807 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
808 }
809 
810 #define pmd_write pmd_write
811 static inline int pmd_write(pmd_t pmd)
812 {
813 	return pte_write(pmd_pte(pmd));
814 }
815 
816 #define pud_write pud_write
817 static inline int pud_write(pud_t pud)
818 {
819 	return pte_write(pud_pte(pud));
820 }
821 
822 #define pmd_dirty pmd_dirty
823 static inline int pmd_dirty(pmd_t pmd)
824 {
825 	return pte_dirty(pmd_pte(pmd));
826 }
827 
828 #define pmd_young pmd_young
829 static inline int pmd_young(pmd_t pmd)
830 {
831 	return pte_young(pmd_pte(pmd));
832 }
833 
834 static inline int pmd_user(pmd_t pmd)
835 {
836 	return pte_user(pmd_pte(pmd));
837 }
838 
839 static inline pmd_t pmd_mkold(pmd_t pmd)
840 {
841 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
842 }
843 
844 static inline pmd_t pmd_mkyoung(pmd_t pmd)
845 {
846 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
847 }
848 
849 pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
850 #define pmd_mkwrite pmd_mkwrite
851 
852 static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
853 {
854 	return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)));
855 }
856 
857 static inline pmd_t pmd_mkwrite_shstk(pmd_t pte)
858 {
859 	return __pmd((pmd_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
860 }
861 
862 static inline pmd_t pmd_wrprotect(pmd_t pmd)
863 {
864 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
865 }
866 
867 static inline pmd_t pmd_mkclean(pmd_t pmd)
868 {
869 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
870 }
871 
872 static inline pmd_t pmd_mkdirty(pmd_t pmd)
873 {
874 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
875 }
876 
877 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
878 static inline bool pmd_special(pmd_t pmd)
879 {
880 	return pte_special(pmd_pte(pmd));
881 }
882 
883 static inline pmd_t pmd_mkspecial(pmd_t pmd)
884 {
885 	return pte_pmd(pte_mkspecial(pmd_pte(pmd)));
886 }
887 #endif
888 
889 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
890 static inline bool pud_special(pud_t pud)
891 {
892 	return pte_special(pud_pte(pud));
893 }
894 
895 static inline pud_t pud_mkspecial(pud_t pud)
896 {
897 	return pte_pud(pte_mkspecial(pud_pte(pud)));
898 }
899 #endif
900 
901 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
902 static inline bool pmd_uffd_wp(pmd_t pmd)
903 {
904 	return pte_uffd_wp(pmd_pte(pmd));
905 }
906 
907 static inline pmd_t pmd_mkuffd_wp(pmd_t pmd)
908 {
909 	return pte_pmd(pte_mkuffd_wp(pmd_pte(pmd)));
910 }
911 
912 static inline pmd_t pmd_clear_uffd_wp(pmd_t pmd)
913 {
914 	return pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd)));
915 }
916 
917 static inline bool pmd_swp_uffd_wp(pmd_t pmd)
918 {
919 	return pte_swp_uffd_wp(pmd_pte(pmd));
920 }
921 
922 static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd)
923 {
924 	return pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd)));
925 }
926 
927 static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd)
928 {
929 	return pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd)));
930 }
931 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
932 
933 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
934 static inline bool pmd_soft_dirty(pmd_t pmd)
935 {
936 	return pte_soft_dirty(pmd_pte(pmd));
937 }
938 
939 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
940 {
941 	return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd)));
942 }
943 
944 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
945 {
946 	return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd)));
947 }
948 
949 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
950 static inline bool pmd_swp_soft_dirty(pmd_t pmd)
951 {
952 	return pte_swp_soft_dirty(pmd_pte(pmd));
953 }
954 
955 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
956 {
957 	return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd)));
958 }
959 
960 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
961 {
962 	return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd)));
963 }
964 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
965 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
966 
967 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
968 				pmd_t *pmdp, pmd_t pmd)
969 {
970 	page_table_check_pmd_set(mm, addr, pmdp, pmd);
971 	return __set_pte_at(mm, (pte_t *)pmdp, pmd_pte(pmd));
972 }
973 
974 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
975 				pud_t *pudp, pud_t pud)
976 {
977 	page_table_check_pud_set(mm, addr, pudp, pud);
978 	return __set_pte_at(mm, (pte_t *)pudp, pud_pte(pud));
979 }
980 
981 #ifdef CONFIG_PAGE_TABLE_CHECK
982 static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
983 {
984 	return pte_present(pte) && pte_user(pte);
985 }
986 
987 static inline bool pmd_user_accessible_page(struct mm_struct *mm, unsigned long addr, pmd_t pmd)
988 {
989 	return pmd_leaf(pmd) && pmd_user(pmd);
990 }
991 
992 static inline bool pud_user_accessible_page(struct mm_struct *mm, unsigned long addr, pud_t pud)
993 {
994 	return pud_leaf(pud) && pud_user(pud);
995 }
996 #endif
997 
998 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
999 static inline int pmd_trans_huge(pmd_t pmd)
1000 {
1001 	return pmd_leaf(pmd);
1002 }
1003 
1004 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1005 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1006 					unsigned long address, pmd_t *pmdp,
1007 					pmd_t entry, int dirty)
1008 {
1009 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
1010 }
1011 
1012 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1013 static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
1014 		unsigned long address, pmd_t *pmdp)
1015 {
1016 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1017 }
1018 
1019 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1020 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1021 					unsigned long address, pmd_t *pmdp)
1022 {
1023 #ifdef CONFIG_SMP
1024 	pmd_t pmd = __pmd(xchg(&pmdp->pmd, 0));
1025 #else
1026 	pmd_t pmd = *pmdp;
1027 
1028 	pmd_clear(pmdp);
1029 #endif
1030 
1031 	page_table_check_pmd_clear(mm, address, pmd);
1032 
1033 	return pmd;
1034 }
1035 
1036 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1037 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1038 					unsigned long address, pmd_t *pmdp)
1039 {
1040 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1041 }
1042 
1043 #define pmdp_establish pmdp_establish
1044 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1045 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
1046 {
1047 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
1048 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
1049 }
1050 
1051 #define pmdp_collapse_flush pmdp_collapse_flush
1052 extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
1053 				 unsigned long address, pmd_t *pmdp);
1054 
1055 static inline pud_t pud_wrprotect(pud_t pud)
1056 {
1057 	return pte_pud(pte_wrprotect(pud_pte(pud)));
1058 }
1059 
1060 static inline int pud_trans_huge(pud_t pud)
1061 {
1062 	return pud_leaf(pud);
1063 }
1064 
1065 static inline int pud_dirty(pud_t pud)
1066 {
1067 	return pte_dirty(pud_pte(pud));
1068 }
1069 
1070 static inline pud_t pud_mkyoung(pud_t pud)
1071 {
1072 	return pte_pud(pte_mkyoung(pud_pte(pud)));
1073 }
1074 
1075 static inline pud_t pud_mkold(pud_t pud)
1076 {
1077 	return pte_pud(pte_mkold(pud_pte(pud)));
1078 }
1079 
1080 static inline pud_t pud_mkdirty(pud_t pud)
1081 {
1082 	return pte_pud(pte_mkdirty(pud_pte(pud)));
1083 }
1084 
1085 static inline pud_t pud_mkclean(pud_t pud)
1086 {
1087 	return pte_pud(pte_mkclean(pud_pte(pud)));
1088 }
1089 
1090 static inline pud_t pud_mkwrite(pud_t pud)
1091 {
1092 	return pte_pud(pte_mkwrite_novma(pud_pte(pud)));
1093 }
1094 
1095 static inline pud_t pud_mkhuge(pud_t pud)
1096 {
1097 	return pud;
1098 }
1099 
1100 static inline int pudp_set_access_flags(struct vm_area_struct *vma,
1101 					unsigned long address, pud_t *pudp,
1102 					pud_t entry, int dirty)
1103 {
1104 	return ptep_set_access_flags(vma, address, (pte_t *)pudp, pud_pte(entry), dirty);
1105 }
1106 
1107 static inline bool pudp_test_and_clear_young(struct vm_area_struct *vma,
1108 		unsigned long address, pud_t *pudp)
1109 {
1110 	return ptep_test_and_clear_young(vma, address, (pte_t *)pudp);
1111 }
1112 
1113 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
1114 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
1115 					    unsigned long address,  pud_t *pudp)
1116 {
1117 #ifdef CONFIG_SMP
1118 	pud_t pud = __pud(xchg(&pudp->pud, 0));
1119 #else
1120 	pud_t pud = *pudp;
1121 
1122 	pud_clear(pudp);
1123 #endif
1124 
1125 	page_table_check_pud_clear(mm, address, pud);
1126 
1127 	return pud;
1128 }
1129 
1130 static inline int pud_young(pud_t pud)
1131 {
1132 	return pte_young(pud_pte(pud));
1133 }
1134 
1135 static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
1136 					unsigned long address, pud_t *pudp)
1137 {
1138 	pte_t *ptep = (pte_t *)pudp;
1139 
1140 	update_mmu_cache(vma, address, ptep);
1141 }
1142 
1143 static inline pud_t pudp_establish(struct vm_area_struct *vma,
1144 				   unsigned long address, pud_t *pudp, pud_t pud)
1145 {
1146 	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
1147 	return __pud(atomic_long_xchg((atomic_long_t *)pudp, pud_val(pud)));
1148 }
1149 
1150 static inline pud_t pud_mkinvalid(pud_t pud)
1151 {
1152 	return __pud(pud_val(pud) & ~(_PAGE_PRESENT | _PAGE_PROT_NONE));
1153 }
1154 
1155 extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
1156 			     pud_t *pudp);
1157 
1158 static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
1159 {
1160 	return pte_pud(pte_modify(pud_pte(pud), newprot));
1161 }
1162 
1163 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1164 
1165 /*
1166  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
1167  * are !pte_none() && !pte_present().
1168  *
1169  * Format of swap PTE:
1170  *	bit            0:	_PAGE_PRESENT (zero)
1171  *	bit       1 to 2:	(zero)
1172  *	bit            3:	_PAGE_SWP_SOFT_DIRTY
1173  *	bit            4:	_PAGE_SWP_UFFD_WP
1174  *	bit            5:	_PAGE_PROT_NONE (zero)
1175  *	bit            6:	exclusive marker
1176  *	bits      7 to 11:	swap type
1177  *	bits 12 to XLEN-1:	swap offset
1178  */
1179 #define __SWP_TYPE_SHIFT	7
1180 #define __SWP_TYPE_BITS		5
1181 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
1182 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
1183 
1184 #define MAX_SWAPFILES_CHECK()	\
1185 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1186 
1187 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1188 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
1189 #define __swp_entry(type, offset) ((swp_entry_t) \
1190 	{ (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \
1191 	  ((offset) << __SWP_OFFSET_SHIFT) })
1192 
1193 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1194 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1195 
1196 static inline bool pte_swp_exclusive(pte_t pte)
1197 {
1198 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
1199 }
1200 
1201 static inline pte_t pte_swp_mkexclusive(pte_t pte)
1202 {
1203 	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
1204 }
1205 
1206 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
1207 {
1208 	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
1209 }
1210 
1211 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1212 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
1213 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
1214 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
1215 
1216 /*
1217  * In the RV64 Linux scheme, we give the user half of the virtual-address space
1218  * and give the kernel the other (upper) half.
1219  */
1220 #ifdef CONFIG_64BIT
1221 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
1222 #else
1223 #define KERN_VIRT_START	FIXADDR_START
1224 #endif
1225 
1226 /*
1227  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
1228  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
1229  * Task size is:
1230  * -        0x9fc00000	(~2.5GB) for RV32.
1231  * -      0x4000000000	( 256GB) for RV64 using SV39 mmu
1232  * -    0x800000000000	( 128TB) for RV64 using SV48 mmu
1233  * - 0x100000000000000	(  64PB) for RV64 using SV57 mmu
1234  *
1235  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
1236  * Instruction Set Manual Volume II: Privileged Architecture" states that
1237  * "load and store effective addresses, which are 64bits, must have bits
1238  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
1239  * Similarly for SV57, bits 63–57 must be equal to bit 56.
1240  */
1241 #ifdef CONFIG_64BIT
1242 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
1243 
1244 #ifdef CONFIG_COMPAT
1245 #define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
1246 #define TASK_SIZE	(is_compat_task() ? \
1247 			 TASK_SIZE_32 : TASK_SIZE_64)
1248 #else
1249 #define TASK_SIZE	TASK_SIZE_64
1250 #endif
1251 
1252 #else
1253 #define TASK_SIZE	FIXADDR_START
1254 #endif
1255 
1256 #else /* CONFIG_MMU */
1257 
1258 #define PAGE_SHARED		__pgprot(0)
1259 #define PAGE_KERNEL		__pgprot(0)
1260 #define swapper_pg_dir		NULL
1261 #define TASK_SIZE		_AC(-1, UL)
1262 #define VMALLOC_START		_AC(0, UL)
1263 #define VMALLOC_END		TASK_SIZE
1264 
1265 #endif /* !CONFIG_MMU */
1266 
1267 extern char _start[];
1268 extern void *_dtb_early_va;
1269 extern uintptr_t _dtb_early_pa;
1270 #define dtb_early_va	_dtb_early_va
1271 #define dtb_early_pa	_dtb_early_pa
1272 extern u64 satp_mode;
1273 
1274 void paging_init(void);
1275 void misc_mem_init(void);
1276 
1277 /*
1278  * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
1279  * TLB flush will be required as a result of the "set". For example, use
1280  * in scenarios where it is known ahead of time that the routine is
1281  * setting non-present entries, or re-setting an existing entry to the
1282  * same value. Otherwise, use the typical "set" helpers and flush the
1283  * TLB.
1284  */
1285 #define set_p4d_safe(p4dp, p4d) \
1286 ({ \
1287 	WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
1288 	set_p4d(p4dp, p4d); \
1289 })
1290 
1291 #define set_pgd_safe(pgdp, pgd) \
1292 ({ \
1293 	WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
1294 	set_pgd(pgdp, pgd); \
1295 })
1296 #endif /* !__ASSEMBLER__ */
1297 
1298 #endif /* _ASM_RISCV_PGTABLE_H */
1299