xref: /linux/arch/riscv/include/asm/pgtable.h (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
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 #define PCI_IO_SIZE      SZ_16M
97 #define PCI_IO_END       VMEMMAP_START
98 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
99 
100 #define FIXADDR_TOP      PCI_IO_START
101 #ifdef CONFIG_64BIT
102 #define MAX_FDT_SIZE	 PMD_SIZE
103 #define FIX_FDT_SIZE	 (MAX_FDT_SIZE + SZ_2M)
104 #define FIXADDR_SIZE     (PMD_SIZE + FIX_FDT_SIZE)
105 #else
106 #define MAX_FDT_SIZE	 PGDIR_SIZE
107 #define FIX_FDT_SIZE	 MAX_FDT_SIZE
108 #define FIXADDR_SIZE     (PGDIR_SIZE + FIX_FDT_SIZE)
109 #endif
110 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
111 
112 #endif
113 
114 #ifndef __ASSEMBLER__
115 
116 #include <asm/page.h>
117 #include <asm/tlbflush.h>
118 #include <linux/mm_types.h>
119 #include <asm/compat.h>
120 #include <asm/cpufeature.h>
121 
122 #define __page_val_to_pfn(_val)  (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
123 
124 #ifdef CONFIG_64BIT
125 #include <asm/pgtable-64.h>
126 
127 #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
128 #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
129 #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
130 #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
131 #else
132 #include <asm/pgtable-32.h>
133 #endif /* CONFIG_64BIT */
134 
135 #include <linux/page_table_check.h>
136 
137 #ifdef CONFIG_XIP_KERNEL
138 #define XIP_FIXUP(addr) ({							\
139 	extern char _sdata[], _start[], _end[];					\
140 	uintptr_t __rom_start_data = CONFIG_XIP_PHYS_ADDR			\
141 				+ (uintptr_t)&_sdata - (uintptr_t)&_start;	\
142 	uintptr_t __rom_end_data = CONFIG_XIP_PHYS_ADDR				\
143 				+ (uintptr_t)&_end - (uintptr_t)&_start;	\
144 	uintptr_t __a = (uintptr_t)(addr);					\
145 	(__a >= __rom_start_data && __a < __rom_end_data) ?			\
146 		__a - __rom_start_data + CONFIG_PHYS_RAM_BASE :	__a;		\
147 	})
148 #else
149 #define XIP_FIXUP(addr)		(addr)
150 #endif /* CONFIG_XIP_KERNEL */
151 
152 struct pt_alloc_ops {
153 	pte_t *(*get_pte_virt)(phys_addr_t pa);
154 	phys_addr_t (*alloc_pte)(uintptr_t va);
155 #ifndef __PAGETABLE_PMD_FOLDED
156 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
157 	phys_addr_t (*alloc_pmd)(uintptr_t va);
158 	pud_t *(*get_pud_virt)(phys_addr_t pa);
159 	phys_addr_t (*alloc_pud)(uintptr_t va);
160 	p4d_t *(*get_p4d_virt)(phys_addr_t pa);
161 	phys_addr_t (*alloc_p4d)(uintptr_t va);
162 #endif
163 };
164 
165 extern struct pt_alloc_ops pt_ops __meminitdata;
166 
167 #ifdef CONFIG_MMU
168 /* Number of PGD entries that a user-mode program can use */
169 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
170 
171 /* Page protection bits */
172 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
173 
174 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
175 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
176 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
177 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
178 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
179 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
180 					 _PAGE_EXEC | _PAGE_WRITE)
181 #define PAGE_SHADOWSTACK       __pgprot(_PAGE_BASE | _PAGE_WRITE)
182 
183 #define PAGE_COPY		PAGE_READ
184 #define PAGE_COPY_EXEC		PAGE_READ_EXEC
185 #define PAGE_SHARED		PAGE_WRITE
186 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
187 
188 #define _PAGE_KERNEL		(_PAGE_READ \
189 				| _PAGE_WRITE \
190 				| _PAGE_PRESENT \
191 				| _PAGE_ACCESSED \
192 				| _PAGE_DIRTY \
193 				| _PAGE_GLOBAL)
194 
195 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
196 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
197 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
198 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
199 					 | _PAGE_EXEC)
200 
201 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
202 
203 #define _PAGE_KERNEL_NC ((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_NOCACHE)
204 #define _PAGE_IOREMAP	((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_IO)
205 #define PAGE_KERNEL_IO		__pgprot(_PAGE_IOREMAP)
206 
207 extern pgd_t swapper_pg_dir[];
208 extern pgd_t trampoline_pg_dir[];
209 extern pgd_t early_pg_dir[];
210 
211 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
212 static inline int pmd_present(pmd_t pmd)
213 {
214 	/*
215 	 * Checking for _PAGE_LEAF is needed too because:
216 	 * When splitting a THP, split_huge_page() will temporarily clear
217 	 * the present bit, in this situation, pmd_present() and
218 	 * pmd_trans_huge() still needs to return true.
219 	 */
220 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
221 }
222 #else
223 static inline int pmd_present(pmd_t pmd)
224 {
225 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
226 }
227 #endif
228 
229 static inline int pmd_none(pmd_t pmd)
230 {
231 	return (pmd_val(pmd) == 0);
232 }
233 
234 static inline int pmd_bad(pmd_t pmd)
235 {
236 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
237 }
238 
239 #define pmd_leaf	pmd_leaf
240 static inline bool pmd_leaf(pmd_t pmd)
241 {
242 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
243 }
244 
245 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
246 {
247 	WRITE_ONCE(*pmdp, pmd);
248 }
249 
250 static inline void pmd_clear(pmd_t *pmdp)
251 {
252 	set_pmd(pmdp, __pmd(0));
253 }
254 
255 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
256 {
257 	unsigned long prot_val = pgprot_val(prot);
258 
259 	ALT_THEAD_PMA(prot_val);
260 
261 	return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val);
262 }
263 
264 static inline unsigned long _pgd_pfn(pgd_t pgd)
265 {
266 	return __page_val_to_pfn(pgd_val(pgd));
267 }
268 
269 static inline struct page *pmd_page(pmd_t pmd)
270 {
271 	return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
272 }
273 
274 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
275 {
276 	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
277 }
278 
279 static inline pte_t pmd_pte(pmd_t pmd)
280 {
281 	return __pte(pmd_val(pmd));
282 }
283 
284 static inline pte_t pud_pte(pud_t pud)
285 {
286 	return __pte(pud_val(pud));
287 }
288 
289 #ifdef CONFIG_RISCV_ISA_SVNAPOT
290 
291 static __always_inline bool has_svnapot(void)
292 {
293 	return riscv_has_extension_likely(RISCV_ISA_EXT_SVNAPOT);
294 }
295 
296 static inline unsigned long pte_napot(pte_t pte)
297 {
298 	return pte_val(pte) & _PAGE_NAPOT;
299 }
300 
301 static inline pte_t pte_mknapot(pte_t pte, unsigned int order)
302 {
303 	int pos = order - 1 + _PAGE_PFN_SHIFT;
304 	unsigned long napot_bit = BIT(pos);
305 	unsigned long napot_mask = ~GENMASK(pos, _PAGE_PFN_SHIFT);
306 
307 	return __pte((pte_val(pte) & napot_mask) | napot_bit | _PAGE_NAPOT);
308 }
309 
310 #else
311 
312 static __always_inline bool has_svnapot(void) { return false; }
313 
314 static inline unsigned long pte_napot(pte_t pte)
315 {
316 	return 0;
317 }
318 
319 #endif /* CONFIG_RISCV_ISA_SVNAPOT */
320 
321 /* Yields the page frame number (PFN) of a page table entry */
322 static inline unsigned long pte_pfn(pte_t pte)
323 {
324 	unsigned long res  = __page_val_to_pfn(pte_val(pte));
325 
326 	if (has_svnapot() && pte_napot(pte))
327 		res = res & (res - 1UL);
328 
329 	return res;
330 }
331 
332 #define pte_page(x)     pfn_to_page(pte_pfn(x))
333 
334 /* Constructs a page table entry */
335 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
336 {
337 	unsigned long prot_val = pgprot_val(prot);
338 
339 	ALT_THEAD_PMA(prot_val);
340 
341 	return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val);
342 }
343 
344 #define pte_pgprot pte_pgprot
345 static inline pgprot_t pte_pgprot(pte_t pte)
346 {
347 	unsigned long pfn = pte_pfn(pte);
348 
349 	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
350 }
351 
352 static inline int pte_present(pte_t pte)
353 {
354 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
355 }
356 
357 #define pte_accessible pte_accessible
358 static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
359 {
360 	if (pte_val(a) & _PAGE_PRESENT)
361 		return true;
362 
363 	if ((pte_val(a) & _PAGE_PROT_NONE) &&
364 	    atomic_read(&mm->tlb_flush_pending))
365 		return true;
366 
367 	return false;
368 }
369 
370 static inline int pte_none(pte_t pte)
371 {
372 	return (pte_val(pte) == 0);
373 }
374 
375 static inline int pte_write(pte_t pte)
376 {
377 	return pte_val(pte) & _PAGE_WRITE;
378 }
379 
380 static inline int pte_exec(pte_t pte)
381 {
382 	return pte_val(pte) & _PAGE_EXEC;
383 }
384 
385 static inline int pte_user(pte_t pte)
386 {
387 	return pte_val(pte) & _PAGE_USER;
388 }
389 
390 static inline int pte_huge(pte_t pte)
391 {
392 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
393 }
394 
395 static inline int pte_dirty(pte_t pte)
396 {
397 	return pte_val(pte) & _PAGE_DIRTY;
398 }
399 
400 static inline int pte_young(pte_t pte)
401 {
402 	return pte_val(pte) & _PAGE_ACCESSED;
403 }
404 
405 static inline int pte_special(pte_t pte)
406 {
407 	return pte_val(pte) & _PAGE_SPECIAL;
408 }
409 
410 /* static inline pte_t pte_rdprotect(pte_t pte) */
411 
412 static inline pte_t pte_wrprotect(pte_t pte)
413 {
414 	return __pte((pte_val(pte) & ~(_PAGE_WRITE)) | (_PAGE_READ));
415 }
416 
417 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
418 #define pgtable_supports_uffd_wp()	\
419 	riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)
420 
421 static inline bool pte_uffd_wp(pte_t pte)
422 {
423 	return !!(pte_val(pte) & _PAGE_UFFD_WP);
424 }
425 
426 static inline pte_t pte_mkuffd_wp(pte_t pte)
427 {
428 	return pte_wrprotect(__pte(pte_val(pte) | _PAGE_UFFD_WP));
429 }
430 
431 static inline pte_t pte_clear_uffd_wp(pte_t pte)
432 {
433 	return __pte(pte_val(pte) & ~(_PAGE_UFFD_WP));
434 }
435 
436 static inline bool pte_swp_uffd_wp(pte_t pte)
437 {
438 	return !!(pte_val(pte) & _PAGE_SWP_UFFD_WP);
439 }
440 
441 static inline pte_t pte_swp_mkuffd_wp(pte_t pte)
442 {
443 	return __pte(pte_val(pte) | _PAGE_SWP_UFFD_WP);
444 }
445 
446 static inline pte_t pte_swp_clear_uffd_wp(pte_t pte)
447 {
448 	return __pte(pte_val(pte) & ~(_PAGE_SWP_UFFD_WP));
449 }
450 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
451 
452 /* static inline pte_t pte_mkread(pte_t pte) */
453 
454 struct vm_area_struct;
455 pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma);
456 #define pte_mkwrite pte_mkwrite
457 
458 static inline pte_t pte_mkwrite_novma(pte_t pte)
459 {
460 	return __pte(pte_val(pte) | _PAGE_WRITE);
461 }
462 
463 static inline pte_t pte_mkwrite_shstk(pte_t pte)
464 {
465 	return __pte((pte_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
466 }
467 
468 /* static inline pte_t pte_mkexec(pte_t pte) */
469 
470 static inline pte_t pte_mkdirty(pte_t pte)
471 {
472 	return __pte(pte_val(pte) | _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
473 }
474 
475 static inline pte_t pte_mkclean(pte_t pte)
476 {
477 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
478 }
479 
480 static inline pte_t pte_mkyoung(pte_t pte)
481 {
482 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
483 }
484 
485 static inline pte_t pte_mkold(pte_t pte)
486 {
487 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
488 }
489 
490 static inline pte_t pte_mkspecial(pte_t pte)
491 {
492 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
493 }
494 
495 static inline pte_t pte_mkhuge(pte_t pte)
496 {
497 	return pte;
498 }
499 
500 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
501 #define pgtable_supports_soft_dirty()				\
502 	(IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) &&			\
503 	 riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B))
504 
505 static inline bool pte_soft_dirty(pte_t pte)
506 {
507 	return !!(pte_val(pte) & _PAGE_SOFT_DIRTY);
508 }
509 
510 static inline pte_t pte_mksoft_dirty(pte_t pte)
511 {
512 	return __pte(pte_val(pte) | _PAGE_SOFT_DIRTY);
513 }
514 
515 static inline pte_t pte_clear_soft_dirty(pte_t pte)
516 {
517 	return __pte(pte_val(pte) & ~(_PAGE_SOFT_DIRTY));
518 }
519 
520 static inline bool pte_swp_soft_dirty(pte_t pte)
521 {
522 	return !!(pte_val(pte) & _PAGE_SWP_SOFT_DIRTY);
523 }
524 
525 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
526 {
527 	return __pte(pte_val(pte) | _PAGE_SWP_SOFT_DIRTY);
528 }
529 
530 static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
531 {
532 	return __pte(pte_val(pte) & ~(_PAGE_SWP_SOFT_DIRTY));
533 }
534 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
535 
536 #ifdef CONFIG_RISCV_ISA_SVNAPOT
537 #define pte_leaf_size(pte)	(pte_napot(pte) ?				\
538 					napot_cont_size(napot_cont_order(pte)) :\
539 					PAGE_SIZE)
540 #endif
541 
542 #ifdef CONFIG_NUMA_BALANCING
543 /*
544  * See the comment in include/asm-generic/pgtable.h
545  */
546 static inline int pte_protnone(pte_t pte)
547 {
548 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
549 }
550 
551 static inline int pmd_protnone(pmd_t pmd)
552 {
553 	return pte_protnone(pmd_pte(pmd));
554 }
555 #endif
556 
557 /* Modify page protection bits */
558 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
559 {
560 	unsigned long newprot_val = pgprot_val(newprot);
561 
562 	ALT_THEAD_PMA(newprot_val);
563 
564 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val);
565 }
566 
567 #define pgd_ERROR(e) \
568 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
569 
570 
571 /* Commit new configuration to MMU hardware */
572 static inline void update_mmu_cache_range(struct vm_fault *vmf,
573 		struct vm_area_struct *vma, unsigned long address,
574 		pte_t *ptep, unsigned int nr)
575 {
576 	/*
577 	 * Svvptc guarantees that the new valid pte will be visible within
578 	 * a bounded timeframe, so when the uarch does not cache invalid
579 	 * entries, we don't have to do anything.
580 	 */
581 	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SVVPTC))
582 		return;
583 
584 	/*
585 	 * The kernel assumes that TLBs don't cache invalid entries, but
586 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
587 	 * cache flush; it is necessary even after writing invalid entries.
588 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
589 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
590 	 */
591 	while (nr--)
592 		local_flush_tlb_page(address + nr * PAGE_SIZE);
593 
594 }
595 #define update_mmu_cache(vma, addr, ptep) \
596 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
597 
598 #define update_mmu_tlb_range(vma, addr, ptep, nr) \
599 	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
600 
601 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
602 		unsigned long address, pmd_t *pmdp)
603 {
604 	pte_t *ptep = (pte_t *)pmdp;
605 
606 	update_mmu_cache(vma, address, ptep);
607 }
608 
609 #define __HAVE_ARCH_PTE_SAME
610 static inline int pte_same(pte_t pte_a, pte_t pte_b)
611 {
612 	return pte_val(pte_a) == pte_val(pte_b);
613 }
614 
615 /*
616  * Certain architectures need to do special things when PTEs within
617  * a page table are directly modified.  Thus, the following hook is
618  * made available.
619  */
620 static inline void set_pte(pte_t *ptep, pte_t pteval)
621 {
622 	WRITE_ONCE(*ptep, pteval);
623 }
624 
625 void flush_icache_pte(struct mm_struct *mm, pte_t pte);
626 
627 static inline void __set_pte_at(struct mm_struct *mm, pte_t *ptep, pte_t pteval)
628 {
629 	if (pte_present(pteval) && pte_exec(pteval))
630 		flush_icache_pte(mm, pteval);
631 
632 	set_pte(ptep, pteval);
633 }
634 
635 #define PFN_PTE_SHIFT		_PAGE_PFN_SHIFT
636 
637 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
638 		pte_t *ptep, pte_t pteval, unsigned int nr)
639 {
640 	page_table_check_ptes_set(mm, addr, ptep, pteval, nr);
641 
642 	for (;;) {
643 		__set_pte_at(mm, ptep, pteval);
644 		if (--nr == 0)
645 			break;
646 		ptep++;
647 		pte_val(pteval) += 1 << _PAGE_PFN_SHIFT;
648 	}
649 }
650 #define set_ptes set_ptes
651 
652 static inline void pte_clear(struct mm_struct *mm,
653 	unsigned long addr, pte_t *ptep)
654 {
655 	__set_pte_at(mm, ptep, __pte(0));
656 }
657 
658 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS	/* defined in mm/pgtable.c */
659 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
660 				 pte_t *ptep, pte_t entry, int dirty);
661 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG	/* defined in mm/pgtable.c */
662 extern int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long address,
663 				     pte_t *ptep);
664 
665 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
666 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
667 				       unsigned long address, pte_t *ptep)
668 {
669 #ifdef CONFIG_SMP
670 	pte_t pte = __pte(xchg(&ptep->pte, 0));
671 #else
672 	pte_t pte = *ptep;
673 
674 	set_pte(ptep, __pte(0));
675 #endif
676 
677 	page_table_check_pte_clear(mm, address, pte);
678 
679 	return pte;
680 }
681 
682 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
683 static inline void ptep_set_wrprotect(struct mm_struct *mm,
684 				      unsigned long address, pte_t *ptep)
685 {
686 	pte_t read_pte = READ_ONCE(*ptep);
687 	/*
688 	 * ptep_set_wrprotect can be called for shadow stack ranges too.
689 	 * shadow stack memory is XWR = 010 and thus clearing _PAGE_WRITE will lead to
690 	 * encoding 000b which is wrong encoding with V = 1. This should lead to page fault
691 	 * but we dont want this wrong configuration to be set in page tables.
692 	 */
693 	atomic_long_set((atomic_long_t *)ptep,
694 			((pte_val(read_pte) & ~(unsigned long)_PAGE_WRITE) | _PAGE_READ));
695 }
696 
697 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
698 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
699 					 unsigned long address, pte_t *ptep)
700 {
701 	/*
702 	 * This comment is borrowed from x86, but applies equally to RISC-V:
703 	 *
704 	 * Clearing the accessed bit without a TLB flush
705 	 * doesn't cause data corruption. [ It could cause incorrect
706 	 * page aging and the (mistaken) reclaim of hot pages, but the
707 	 * chance of that should be relatively low. ]
708 	 *
709 	 * So as a performance optimization don't flush the TLB when
710 	 * clearing the accessed bit, it will eventually be flushed by
711 	 * a context switch or a VM operation anyway. [ In the rare
712 	 * event of it not getting flushed for a long time the delay
713 	 * shouldn't really matter because there's no real memory
714 	 * pressure for swapout to react to. ]
715 	 */
716 	return ptep_test_and_clear_young(vma, address, ptep);
717 }
718 
719 #define pgprot_nx pgprot_nx
720 static inline pgprot_t pgprot_nx(pgprot_t _prot)
721 {
722 	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
723 }
724 
725 #define pgprot_noncached pgprot_noncached
726 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
727 {
728 	unsigned long prot = pgprot_val(_prot);
729 
730 	prot &= ~_PAGE_MTMASK;
731 	prot |= _PAGE_IO;
732 
733 	return __pgprot(prot);
734 }
735 
736 #define pgprot_writecombine pgprot_writecombine
737 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
738 {
739 	unsigned long prot = pgprot_val(_prot);
740 
741 	prot &= ~_PAGE_MTMASK;
742 	prot |= _PAGE_NOCACHE;
743 
744 	return __pgprot(prot);
745 }
746 
747 #define pgprot_dmacoherent pgprot_writecombine
748 
749 /*
750  * Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By
751  * default the M-mode firmware enables the hardware updating scheme when only Svadu is present in
752  * DT.
753  */
754 #define arch_has_hw_pte_young arch_has_hw_pte_young
755 static inline bool arch_has_hw_pte_young(void)
756 {
757 	return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
758 }
759 
760 /*
761  * THP functions
762  */
763 static inline pmd_t pte_pmd(pte_t pte)
764 {
765 	return __pmd(pte_val(pte));
766 }
767 
768 static inline pud_t pte_pud(pte_t pte)
769 {
770 	return __pud(pte_val(pte));
771 }
772 
773 static inline pmd_t pmd_mkhuge(pmd_t pmd)
774 {
775 	return pmd;
776 }
777 
778 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
779 {
780 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
781 }
782 
783 #define __pmd_to_phys(pmd)  (__page_val_to_pfn(pmd_val(pmd)) << PAGE_SHIFT)
784 
785 static inline unsigned long pmd_pfn(pmd_t pmd)
786 {
787 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
788 }
789 
790 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
791 
792 #define pud_pfn pud_pfn
793 static inline unsigned long pud_pfn(pud_t pud)
794 {
795 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
796 }
797 
798 #define pmd_pgprot pmd_pgprot
799 static inline pgprot_t pmd_pgprot(pmd_t pmd)
800 {
801 	return pte_pgprot(pmd_pte(pmd));
802 }
803 
804 #define pud_pgprot pud_pgprot
805 static inline pgprot_t pud_pgprot(pud_t pud)
806 {
807 	return pte_pgprot(pud_pte(pud));
808 }
809 
810 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
811 {
812 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
813 }
814 
815 #define pmd_write pmd_write
816 static inline int pmd_write(pmd_t pmd)
817 {
818 	return pte_write(pmd_pte(pmd));
819 }
820 
821 #define pud_write pud_write
822 static inline int pud_write(pud_t pud)
823 {
824 	return pte_write(pud_pte(pud));
825 }
826 
827 #define pmd_dirty pmd_dirty
828 static inline int pmd_dirty(pmd_t pmd)
829 {
830 	return pte_dirty(pmd_pte(pmd));
831 }
832 
833 #define pmd_young pmd_young
834 static inline int pmd_young(pmd_t pmd)
835 {
836 	return pte_young(pmd_pte(pmd));
837 }
838 
839 static inline int pmd_user(pmd_t pmd)
840 {
841 	return pte_user(pmd_pte(pmd));
842 }
843 
844 static inline pmd_t pmd_mkold(pmd_t pmd)
845 {
846 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
847 }
848 
849 static inline pmd_t pmd_mkyoung(pmd_t pmd)
850 {
851 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
852 }
853 
854 pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
855 #define pmd_mkwrite pmd_mkwrite
856 
857 static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
858 {
859 	return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)));
860 }
861 
862 static inline pmd_t pmd_mkwrite_shstk(pmd_t pte)
863 {
864 	return __pmd((pmd_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
865 }
866 
867 static inline pmd_t pmd_wrprotect(pmd_t pmd)
868 {
869 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
870 }
871 
872 static inline pmd_t pmd_mkclean(pmd_t pmd)
873 {
874 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
875 }
876 
877 static inline pmd_t pmd_mkdirty(pmd_t pmd)
878 {
879 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
880 }
881 
882 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
883 static inline bool pmd_special(pmd_t pmd)
884 {
885 	return pte_special(pmd_pte(pmd));
886 }
887 
888 static inline pmd_t pmd_mkspecial(pmd_t pmd)
889 {
890 	return pte_pmd(pte_mkspecial(pmd_pte(pmd)));
891 }
892 #endif
893 
894 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
895 static inline bool pud_special(pud_t pud)
896 {
897 	return pte_special(pud_pte(pud));
898 }
899 
900 static inline pud_t pud_mkspecial(pud_t pud)
901 {
902 	return pte_pud(pte_mkspecial(pud_pte(pud)));
903 }
904 #endif
905 
906 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
907 static inline bool pmd_uffd_wp(pmd_t pmd)
908 {
909 	return pte_uffd_wp(pmd_pte(pmd));
910 }
911 
912 static inline pmd_t pmd_mkuffd_wp(pmd_t pmd)
913 {
914 	return pte_pmd(pte_mkuffd_wp(pmd_pte(pmd)));
915 }
916 
917 static inline pmd_t pmd_clear_uffd_wp(pmd_t pmd)
918 {
919 	return pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd)));
920 }
921 
922 static inline bool pmd_swp_uffd_wp(pmd_t pmd)
923 {
924 	return pte_swp_uffd_wp(pmd_pte(pmd));
925 }
926 
927 static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd)
928 {
929 	return pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd)));
930 }
931 
932 static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd)
933 {
934 	return pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd)));
935 }
936 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
937 
938 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
939 static inline bool pmd_soft_dirty(pmd_t pmd)
940 {
941 	return pte_soft_dirty(pmd_pte(pmd));
942 }
943 
944 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
945 {
946 	return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd)));
947 }
948 
949 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
950 {
951 	return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd)));
952 }
953 
954 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
955 static inline bool pmd_swp_soft_dirty(pmd_t pmd)
956 {
957 	return pte_swp_soft_dirty(pmd_pte(pmd));
958 }
959 
960 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
961 {
962 	return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd)));
963 }
964 
965 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
966 {
967 	return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd)));
968 }
969 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
970 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
971 
972 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
973 				pmd_t *pmdp, pmd_t pmd)
974 {
975 	page_table_check_pmd_set(mm, addr, pmdp, pmd);
976 	return __set_pte_at(mm, (pte_t *)pmdp, pmd_pte(pmd));
977 }
978 
979 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
980 				pud_t *pudp, pud_t pud)
981 {
982 	page_table_check_pud_set(mm, addr, pudp, pud);
983 	return __set_pte_at(mm, (pte_t *)pudp, pud_pte(pud));
984 }
985 
986 #ifdef CONFIG_PAGE_TABLE_CHECK
987 static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
988 {
989 	return pte_present(pte) && pte_user(pte);
990 }
991 
992 static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
993 {
994 	return pmd_leaf(pmd) && pmd_user(pmd);
995 }
996 
997 static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
998 {
999 	return pud_leaf(pud) && pud_user(pud);
1000 }
1001 #endif
1002 
1003 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1004 static inline int pmd_trans_huge(pmd_t pmd)
1005 {
1006 	return pmd_leaf(pmd);
1007 }
1008 
1009 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1010 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1011 					unsigned long address, pmd_t *pmdp,
1012 					pmd_t entry, int dirty)
1013 {
1014 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
1015 }
1016 
1017 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1018 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
1019 					unsigned long address, pmd_t *pmdp)
1020 {
1021 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1022 }
1023 
1024 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1025 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1026 					unsigned long address, pmd_t *pmdp)
1027 {
1028 #ifdef CONFIG_SMP
1029 	pmd_t pmd = __pmd(xchg(&pmdp->pmd, 0));
1030 #else
1031 	pmd_t pmd = *pmdp;
1032 
1033 	pmd_clear(pmdp);
1034 #endif
1035 
1036 	page_table_check_pmd_clear(mm, address, pmd);
1037 
1038 	return pmd;
1039 }
1040 
1041 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1042 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1043 					unsigned long address, pmd_t *pmdp)
1044 {
1045 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1046 }
1047 
1048 #define pmdp_establish pmdp_establish
1049 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1050 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
1051 {
1052 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
1053 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
1054 }
1055 
1056 #define pmdp_collapse_flush pmdp_collapse_flush
1057 extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
1058 				 unsigned long address, pmd_t *pmdp);
1059 
1060 static inline pud_t pud_wrprotect(pud_t pud)
1061 {
1062 	return pte_pud(pte_wrprotect(pud_pte(pud)));
1063 }
1064 
1065 static inline int pud_trans_huge(pud_t pud)
1066 {
1067 	return pud_leaf(pud);
1068 }
1069 
1070 static inline int pud_dirty(pud_t pud)
1071 {
1072 	return pte_dirty(pud_pte(pud));
1073 }
1074 
1075 static inline pud_t pud_mkyoung(pud_t pud)
1076 {
1077 	return pte_pud(pte_mkyoung(pud_pte(pud)));
1078 }
1079 
1080 static inline pud_t pud_mkold(pud_t pud)
1081 {
1082 	return pte_pud(pte_mkold(pud_pte(pud)));
1083 }
1084 
1085 static inline pud_t pud_mkdirty(pud_t pud)
1086 {
1087 	return pte_pud(pte_mkdirty(pud_pte(pud)));
1088 }
1089 
1090 static inline pud_t pud_mkclean(pud_t pud)
1091 {
1092 	return pte_pud(pte_mkclean(pud_pte(pud)));
1093 }
1094 
1095 static inline pud_t pud_mkwrite(pud_t pud)
1096 {
1097 	return pte_pud(pte_mkwrite_novma(pud_pte(pud)));
1098 }
1099 
1100 static inline pud_t pud_mkhuge(pud_t pud)
1101 {
1102 	return pud;
1103 }
1104 
1105 static inline int pudp_set_access_flags(struct vm_area_struct *vma,
1106 					unsigned long address, pud_t *pudp,
1107 					pud_t entry, int dirty)
1108 {
1109 	return ptep_set_access_flags(vma, address, (pte_t *)pudp, pud_pte(entry), dirty);
1110 }
1111 
1112 static inline int pudp_test_and_clear_young(struct vm_area_struct *vma,
1113 					    unsigned long address, pud_t *pudp)
1114 {
1115 	return ptep_test_and_clear_young(vma, address, (pte_t *)pudp);
1116 }
1117 
1118 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
1119 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
1120 					    unsigned long address,  pud_t *pudp)
1121 {
1122 #ifdef CONFIG_SMP
1123 	pud_t pud = __pud(xchg(&pudp->pud, 0));
1124 #else
1125 	pud_t pud = *pudp;
1126 
1127 	pud_clear(pudp);
1128 #endif
1129 
1130 	page_table_check_pud_clear(mm, address, pud);
1131 
1132 	return pud;
1133 }
1134 
1135 static inline int pud_young(pud_t pud)
1136 {
1137 	return pte_young(pud_pte(pud));
1138 }
1139 
1140 static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
1141 					unsigned long address, pud_t *pudp)
1142 {
1143 	pte_t *ptep = (pte_t *)pudp;
1144 
1145 	update_mmu_cache(vma, address, ptep);
1146 }
1147 
1148 static inline pud_t pudp_establish(struct vm_area_struct *vma,
1149 				   unsigned long address, pud_t *pudp, pud_t pud)
1150 {
1151 	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
1152 	return __pud(atomic_long_xchg((atomic_long_t *)pudp, pud_val(pud)));
1153 }
1154 
1155 static inline pud_t pud_mkinvalid(pud_t pud)
1156 {
1157 	return __pud(pud_val(pud) & ~(_PAGE_PRESENT | _PAGE_PROT_NONE));
1158 }
1159 
1160 extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
1161 			     pud_t *pudp);
1162 
1163 static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
1164 {
1165 	return pte_pud(pte_modify(pud_pte(pud), newprot));
1166 }
1167 
1168 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1169 
1170 /*
1171  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
1172  * are !pte_none() && !pte_present().
1173  *
1174  * Format of swap PTE:
1175  *	bit            0:	_PAGE_PRESENT (zero)
1176  *	bit       1 to 2:	(zero)
1177  *	bit            3:	_PAGE_SWP_SOFT_DIRTY
1178  *	bit            4:	_PAGE_SWP_UFFD_WP
1179  *	bit            5:	_PAGE_PROT_NONE (zero)
1180  *	bit            6:	exclusive marker
1181  *	bits      7 to 11:	swap type
1182  *	bits 12 to XLEN-1:	swap offset
1183  */
1184 #define __SWP_TYPE_SHIFT	7
1185 #define __SWP_TYPE_BITS		5
1186 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
1187 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
1188 
1189 #define MAX_SWAPFILES_CHECK()	\
1190 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1191 
1192 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1193 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
1194 #define __swp_entry(type, offset) ((swp_entry_t) \
1195 	{ (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \
1196 	  ((offset) << __SWP_OFFSET_SHIFT) })
1197 
1198 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1199 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1200 
1201 static inline bool pte_swp_exclusive(pte_t pte)
1202 {
1203 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
1204 }
1205 
1206 static inline pte_t pte_swp_mkexclusive(pte_t pte)
1207 {
1208 	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
1209 }
1210 
1211 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
1212 {
1213 	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
1214 }
1215 
1216 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
1217 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
1218 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
1219 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
1220 
1221 /*
1222  * In the RV64 Linux scheme, we give the user half of the virtual-address space
1223  * and give the kernel the other (upper) half.
1224  */
1225 #ifdef CONFIG_64BIT
1226 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
1227 #else
1228 #define KERN_VIRT_START	FIXADDR_START
1229 #endif
1230 
1231 /*
1232  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
1233  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
1234  * Task size is:
1235  * -        0x9fc00000	(~2.5GB) for RV32.
1236  * -      0x4000000000	( 256GB) for RV64 using SV39 mmu
1237  * -    0x800000000000	( 128TB) for RV64 using SV48 mmu
1238  * - 0x100000000000000	(  64PB) for RV64 using SV57 mmu
1239  *
1240  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
1241  * Instruction Set Manual Volume II: Privileged Architecture" states that
1242  * "load and store effective addresses, which are 64bits, must have bits
1243  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
1244  * Similarly for SV57, bits 63–57 must be equal to bit 56.
1245  */
1246 #ifdef CONFIG_64BIT
1247 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
1248 
1249 #ifdef CONFIG_COMPAT
1250 #define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
1251 #define TASK_SIZE	(is_compat_task() ? \
1252 			 TASK_SIZE_32 : TASK_SIZE_64)
1253 #else
1254 #define TASK_SIZE	TASK_SIZE_64
1255 #endif
1256 
1257 #else
1258 #define TASK_SIZE	FIXADDR_START
1259 #endif
1260 
1261 #else /* CONFIG_MMU */
1262 
1263 #define PAGE_SHARED		__pgprot(0)
1264 #define PAGE_KERNEL		__pgprot(0)
1265 #define swapper_pg_dir		NULL
1266 #define TASK_SIZE		_AC(-1, UL)
1267 #define VMALLOC_START		_AC(0, UL)
1268 #define VMALLOC_END		TASK_SIZE
1269 
1270 #endif /* !CONFIG_MMU */
1271 
1272 extern char _start[];
1273 extern void *_dtb_early_va;
1274 extern uintptr_t _dtb_early_pa;
1275 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
1276 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
1277 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
1278 #else
1279 #define dtb_early_va	_dtb_early_va
1280 #define dtb_early_pa	_dtb_early_pa
1281 #endif /* CONFIG_XIP_KERNEL */
1282 extern u64 satp_mode;
1283 
1284 void paging_init(void);
1285 void misc_mem_init(void);
1286 
1287 /*
1288  * ZERO_PAGE is a global shared page that is always zero,
1289  * used for zero-mapped memory areas, etc.
1290  */
1291 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
1292 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
1293 
1294 /*
1295  * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
1296  * TLB flush will be required as a result of the "set". For example, use
1297  * in scenarios where it is known ahead of time that the routine is
1298  * setting non-present entries, or re-setting an existing entry to the
1299  * same value. Otherwise, use the typical "set" helpers and flush the
1300  * TLB.
1301  */
1302 #define set_p4d_safe(p4dp, p4d) \
1303 ({ \
1304 	WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
1305 	set_p4d(p4dp, p4d); \
1306 })
1307 
1308 #define set_pgd_safe(pgdp, pgd) \
1309 ({ \
1310 	WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
1311 	set_pgd(pgdp, pgd); \
1312 })
1313 #endif /* !__ASSEMBLER__ */
1314 
1315 #endif /* _ASM_RISCV_PGTABLE_H */
1316