xref: /linux/arch/riscv/include/asm/pgtable.h (revision 570f7e331f5febb30f1384817463c7e42b65ca7d)
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()	\
414 	riscv_has_extension_unlikely(RISCV_ISA_EXT_SVRSW60T59B)
415 
416 static inline bool pte_uffd(pte_t pte)
417 {
418 	return !!(pte_val(pte) & _PAGE_UFFD);
419 }
420 
421 static inline pte_t pte_mkuffd(pte_t pte)
422 {
423 	return pte_wrprotect(__pte(pte_val(pte) | _PAGE_UFFD));
424 }
425 
426 static inline pte_t pte_clear_uffd(pte_t pte)
427 {
428 	return __pte(pte_val(pte) & ~(_PAGE_UFFD));
429 }
430 
431 static inline bool pte_swp_uffd(pte_t pte)
432 {
433 	return !!(pte_val(pte) & _PAGE_SWP_UFFD);
434 }
435 
436 static inline pte_t pte_swp_mkuffd(pte_t pte)
437 {
438 	return __pte(pte_val(pte) | _PAGE_SWP_UFFD);
439 }
440 
441 static inline pte_t pte_swp_clear_uffd(pte_t pte)
442 {
443 	return __pte(pte_val(pte) & ~(_PAGE_SWP_UFFD));
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_ARCH_HAS_PTE_PROTNONE
538 static inline int pte_protnone(pte_t pte)
539 {
540 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
541 }
542 
543 static inline int pmd_protnone(pmd_t pmd)
544 {
545 	return pte_protnone(pmd_pte(pmd));
546 }
547 #endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
548 
549 /* Modify page protection bits */
550 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
551 {
552 	unsigned long newprot_val = pgprot_val(newprot);
553 
554 	ALT_THEAD_PMA(newprot_val);
555 
556 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val);
557 }
558 
559 #define pgd_ERROR(e) \
560 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
561 
562 
563 /* Commit new configuration to MMU hardware */
564 static inline void update_mmu_cache_range(struct vm_fault *vmf,
565 		struct vm_area_struct *vma, unsigned long address,
566 		pte_t *ptep, unsigned int nr)
567 {
568 	unsigned long asid = get_mm_asid(vma->vm_mm);
569 
570 	/*
571 	 * Svvptc guarantees that the new valid pte will be visible within
572 	 * a bounded timeframe, so when the uarch does not cache invalid
573 	 * entries, we don't have to do anything.
574 	 */
575 	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SVVPTC))
576 		return;
577 
578 	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SVINVAL)) {
579 		local_sfence_w_inval();
580 		while (nr--)
581 			local_sinval_vma(address + nr * PAGE_SIZE, asid);
582 		local_sfence_inval_ir();
583 		return;
584 	}
585 
586 	/*
587 	 * The kernel assumes that TLBs don't cache invalid entries, but
588 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
589 	 * cache flush; it is necessary even after writing invalid entries.
590 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
591 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
592 	 */
593 	while (nr--)
594 		local_flush_tlb_page_asid(address + nr * PAGE_SIZE, asid);
595 
596 }
597 #define update_mmu_cache(vma, addr, ptep) \
598 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
599 
600 #define update_mmu_tlb_range(vma, addr, ptep, nr) \
601 	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
602 
603 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
604 		unsigned long address, pmd_t *pmdp)
605 {
606 	pte_t *ptep = (pte_t *)pmdp;
607 
608 	update_mmu_cache(vma, address, ptep);
609 }
610 
611 #define __HAVE_ARCH_PTE_SAME
612 static inline int pte_same(pte_t pte_a, pte_t pte_b)
613 {
614 	return pte_val(pte_a) == pte_val(pte_b);
615 }
616 
617 /*
618  * Certain architectures need to do special things when PTEs within
619  * a page table are directly modified.  Thus, the following hook is
620  * made available.
621  */
622 static inline void set_pte(pte_t *ptep, pte_t pteval)
623 {
624 	WRITE_ONCE(*ptep, pteval);
625 }
626 
627 void flush_icache_pte(struct mm_struct *mm, pte_t pte);
628 
629 static inline void __set_pte_at(struct mm_struct *mm, pte_t *ptep, pte_t pteval)
630 {
631 	if (pte_present(pteval) && pte_exec(pteval))
632 		flush_icache_pte(mm, pteval);
633 
634 	set_pte(ptep, pteval);
635 }
636 
637 #define PFN_PTE_SHIFT		_PAGE_PFN_SHIFT
638 
639 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
640 		pte_t *ptep, pte_t pteval, unsigned int nr)
641 {
642 	page_table_check_ptes_set(mm, addr, ptep, pteval, nr);
643 
644 	for (;;) {
645 		__set_pte_at(mm, ptep, pteval);
646 		if (--nr == 0)
647 			break;
648 		ptep++;
649 		pte_val(pteval) += 1 << _PAGE_PFN_SHIFT;
650 	}
651 }
652 #define set_ptes set_ptes
653 
654 static inline void pte_clear(struct mm_struct *mm,
655 	unsigned long addr, pte_t *ptep)
656 {
657 	__set_pte_at(mm, ptep, __pte(0));
658 }
659 
660 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS	/* defined in mm/pgtable.c */
661 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
662 				 pte_t *ptep, pte_t entry, int dirty);
663 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG	/* defined in mm/pgtable.c */
664 bool ptep_test_and_clear_young(struct vm_area_struct *vma,
665 		unsigned long address, pte_t *ptep);
666 
667 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
668 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
669 				       unsigned long address, pte_t *ptep)
670 {
671 #ifdef CONFIG_SMP
672 	pte_t pte = __pte(xchg(&ptep->pte, 0));
673 #else
674 	pte_t pte = *ptep;
675 
676 	set_pte(ptep, __pte(0));
677 #endif
678 
679 	page_table_check_pte_clear(mm, address, pte);
680 
681 	return pte;
682 }
683 
684 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
685 static inline void ptep_set_wrprotect(struct mm_struct *mm,
686 				      unsigned long address, pte_t *ptep)
687 {
688 	pte_t read_pte = READ_ONCE(*ptep);
689 	/*
690 	 * ptep_set_wrprotect can be called for shadow stack ranges too.
691 	 * shadow stack memory is XWR = 010 and thus clearing _PAGE_WRITE will lead to
692 	 * encoding 000b which is wrong encoding with V = 1. This should lead to page fault
693 	 * but we dont want this wrong configuration to be set in page tables.
694 	 */
695 	atomic_long_set((atomic_long_t *)ptep,
696 			((pte_val(read_pte) & ~(unsigned long)_PAGE_WRITE) | _PAGE_READ));
697 }
698 
699 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
700 static inline bool ptep_clear_flush_young(struct vm_area_struct *vma,
701 		unsigned long address, pte_t *ptep)
702 {
703 	/*
704 	 * This comment is borrowed from x86, but applies equally to RISC-V:
705 	 *
706 	 * Clearing the accessed bit without a TLB flush
707 	 * doesn't cause data corruption. [ It could cause incorrect
708 	 * page aging and the (mistaken) reclaim of hot pages, but the
709 	 * chance of that should be relatively low. ]
710 	 *
711 	 * So as a performance optimization don't flush the TLB when
712 	 * clearing the accessed bit, it will eventually be flushed by
713 	 * a context switch or a VM operation anyway. [ In the rare
714 	 * event of it not getting flushed for a long time the delay
715 	 * shouldn't really matter because there's no real memory
716 	 * pressure for swapout to react to. ]
717 	 */
718 	return ptep_test_and_clear_young(vma, address, ptep);
719 }
720 
721 #define pgprot_nx pgprot_nx
722 static inline pgprot_t pgprot_nx(pgprot_t _prot)
723 {
724 	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
725 }
726 
727 #define pgprot_noncached pgprot_noncached
728 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
729 {
730 	unsigned long prot = pgprot_val(_prot);
731 
732 	prot &= ~_PAGE_MTMASK;
733 	prot |= _PAGE_IO;
734 
735 	return __pgprot(prot);
736 }
737 
738 #define pgprot_writecombine pgprot_writecombine
739 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
740 {
741 	unsigned long prot = pgprot_val(_prot);
742 
743 	prot &= ~_PAGE_MTMASK;
744 	prot |= _PAGE_NOCACHE;
745 
746 	return __pgprot(prot);
747 }
748 
749 #define pgprot_dmacoherent pgprot_writecombine
750 
751 /*
752  * Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By
753  * default the M-mode firmware enables the hardware updating scheme when only Svadu is present in
754  * DT.
755  */
756 #define arch_has_hw_pte_young arch_has_hw_pte_young
757 static inline bool arch_has_hw_pte_young(void)
758 {
759 	return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
760 }
761 
762 /*
763  * THP functions
764  */
765 static inline pmd_t pte_pmd(pte_t pte)
766 {
767 	return __pmd(pte_val(pte));
768 }
769 
770 static inline pud_t pte_pud(pte_t pte)
771 {
772 	return __pud(pte_val(pte));
773 }
774 
775 static inline pmd_t pmd_mkhuge(pmd_t pmd)
776 {
777 	return pmd;
778 }
779 
780 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
781 {
782 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
783 }
784 
785 #define __pmd_to_phys(pmd)  (__page_val_to_pfn(pmd_val(pmd)) << PAGE_SHIFT)
786 
787 static inline unsigned long pmd_pfn(pmd_t pmd)
788 {
789 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
790 }
791 
792 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
793 
794 #define pud_pfn pud_pfn
795 static inline unsigned long pud_pfn(pud_t pud)
796 {
797 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
798 }
799 
800 #define pmd_pgprot pmd_pgprot
801 static inline pgprot_t pmd_pgprot(pmd_t pmd)
802 {
803 	return pte_pgprot(pmd_pte(pmd));
804 }
805 
806 #define pud_pgprot pud_pgprot
807 static inline pgprot_t pud_pgprot(pud_t pud)
808 {
809 	return pte_pgprot(pud_pte(pud));
810 }
811 
812 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
813 {
814 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
815 }
816 
817 #define pmd_write pmd_write
818 static inline int pmd_write(pmd_t pmd)
819 {
820 	return pte_write(pmd_pte(pmd));
821 }
822 
823 #define pud_write pud_write
824 static inline int pud_write(pud_t pud)
825 {
826 	return pte_write(pud_pte(pud));
827 }
828 
829 #define pmd_dirty pmd_dirty
830 static inline int pmd_dirty(pmd_t pmd)
831 {
832 	return pte_dirty(pmd_pte(pmd));
833 }
834 
835 #define pmd_young pmd_young
836 static inline int pmd_young(pmd_t pmd)
837 {
838 	return pte_young(pmd_pte(pmd));
839 }
840 
841 static inline int pmd_user(pmd_t pmd)
842 {
843 	return pte_user(pmd_pte(pmd));
844 }
845 
846 static inline pmd_t pmd_mkold(pmd_t pmd)
847 {
848 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
849 }
850 
851 static inline pmd_t pmd_mkyoung(pmd_t pmd)
852 {
853 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
854 }
855 
856 pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
857 #define pmd_mkwrite pmd_mkwrite
858 
859 static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
860 {
861 	return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)));
862 }
863 
864 static inline pmd_t pmd_mkwrite_shstk(pmd_t pte)
865 {
866 	return __pmd((pmd_val(pte) & ~(_PAGE_LEAF)) | _PAGE_WRITE);
867 }
868 
869 static inline pmd_t pmd_wrprotect(pmd_t pmd)
870 {
871 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
872 }
873 
874 static inline pmd_t pmd_mkclean(pmd_t pmd)
875 {
876 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
877 }
878 
879 static inline pmd_t pmd_mkdirty(pmd_t pmd)
880 {
881 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
882 }
883 
884 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
885 static inline bool pmd_special(pmd_t pmd)
886 {
887 	return pte_special(pmd_pte(pmd));
888 }
889 
890 static inline pmd_t pmd_mkspecial(pmd_t pmd)
891 {
892 	return pte_pmd(pte_mkspecial(pmd_pte(pmd)));
893 }
894 #endif
895 
896 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
897 static inline bool pud_special(pud_t pud)
898 {
899 	return pte_special(pud_pte(pud));
900 }
901 
902 static inline pud_t pud_mkspecial(pud_t pud)
903 {
904 	return pte_pud(pte_mkspecial(pud_pte(pud)));
905 }
906 #endif
907 
908 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
909 static inline bool pmd_uffd(pmd_t pmd)
910 {
911 	return pte_uffd(pmd_pte(pmd));
912 }
913 
914 static inline pmd_t pmd_mkuffd(pmd_t pmd)
915 {
916 	return pte_pmd(pte_mkuffd(pmd_pte(pmd)));
917 }
918 
919 static inline pmd_t pmd_clear_uffd(pmd_t pmd)
920 {
921 	return pte_pmd(pte_clear_uffd(pmd_pte(pmd)));
922 }
923 
924 static inline bool pmd_swp_uffd(pmd_t pmd)
925 {
926 	return pte_swp_uffd(pmd_pte(pmd));
927 }
928 
929 static inline pmd_t pmd_swp_mkuffd(pmd_t pmd)
930 {
931 	return pte_pmd(pte_swp_mkuffd(pmd_pte(pmd)));
932 }
933 
934 static inline pmd_t pmd_swp_clear_uffd(pmd_t pmd)
935 {
936 	return pte_pmd(pte_swp_clear_uffd(pmd_pte(pmd)));
937 }
938 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
939 
940 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
941 static inline bool pmd_soft_dirty(pmd_t pmd)
942 {
943 	return pte_soft_dirty(pmd_pte(pmd));
944 }
945 
946 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
947 {
948 	return pte_pmd(pte_mksoft_dirty(pmd_pte(pmd)));
949 }
950 
951 static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
952 {
953 	return pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd)));
954 }
955 
956 #ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
957 static inline bool pmd_swp_soft_dirty(pmd_t pmd)
958 {
959 	return pte_swp_soft_dirty(pmd_pte(pmd));
960 }
961 
962 static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
963 {
964 	return pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd)));
965 }
966 
967 static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
968 {
969 	return pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd)));
970 }
971 #endif /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
972 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
973 
974 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
975 				pmd_t *pmdp, pmd_t pmd)
976 {
977 	page_table_check_pmd_set(mm, addr, pmdp, pmd);
978 	return __set_pte_at(mm, (pte_t *)pmdp, pmd_pte(pmd));
979 }
980 
981 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
982 				pud_t *pudp, pud_t pud)
983 {
984 	page_table_check_pud_set(mm, addr, pudp, pud);
985 	return __set_pte_at(mm, (pte_t *)pudp, pud_pte(pud));
986 }
987 
988 #ifdef CONFIG_PAGE_TABLE_CHECK
989 static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
990 {
991 	return pte_present(pte) && pte_user(pte);
992 }
993 
994 static inline bool pmd_user_accessible_page(struct mm_struct *mm, unsigned long addr, pmd_t pmd)
995 {
996 	return pmd_leaf(pmd) && pmd_user(pmd);
997 }
998 
999 static inline bool pud_user_accessible_page(struct mm_struct *mm, unsigned long addr, pud_t pud)
1000 {
1001 	return pud_leaf(pud) && pud_user(pud);
1002 }
1003 #endif
1004 
1005 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1006 static inline int pmd_trans_huge(pmd_t pmd)
1007 {
1008 	return pmd_leaf(pmd);
1009 }
1010 
1011 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
1012 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
1013 					unsigned long address, pmd_t *pmdp,
1014 					pmd_t entry, int dirty)
1015 {
1016 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
1017 }
1018 
1019 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
1020 static inline bool pmdp_test_and_clear_young(struct vm_area_struct *vma,
1021 		unsigned long address, pmd_t *pmdp)
1022 {
1023 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
1024 }
1025 
1026 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
1027 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
1028 					unsigned long address, pmd_t *pmdp)
1029 {
1030 #ifdef CONFIG_SMP
1031 	pmd_t pmd = __pmd(xchg(&pmdp->pmd, 0));
1032 #else
1033 	pmd_t pmd = *pmdp;
1034 
1035 	pmd_clear(pmdp);
1036 #endif
1037 
1038 	page_table_check_pmd_clear(mm, address, pmd);
1039 
1040 	return pmd;
1041 }
1042 
1043 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
1044 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
1045 					unsigned long address, pmd_t *pmdp)
1046 {
1047 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
1048 }
1049 
1050 #define pmdp_establish pmdp_establish
1051 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
1052 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
1053 {
1054 	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
1055 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
1056 }
1057 
1058 #define pmdp_collapse_flush pmdp_collapse_flush
1059 extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
1060 				 unsigned long address, pmd_t *pmdp);
1061 
1062 static inline pud_t pud_wrprotect(pud_t pud)
1063 {
1064 	return pte_pud(pte_wrprotect(pud_pte(pud)));
1065 }
1066 
1067 static inline int pud_trans_huge(pud_t pud)
1068 {
1069 	return pud_leaf(pud);
1070 }
1071 
1072 static inline int pud_dirty(pud_t pud)
1073 {
1074 	return pte_dirty(pud_pte(pud));
1075 }
1076 
1077 static inline pud_t pud_mkyoung(pud_t pud)
1078 {
1079 	return pte_pud(pte_mkyoung(pud_pte(pud)));
1080 }
1081 
1082 static inline pud_t pud_mkold(pud_t pud)
1083 {
1084 	return pte_pud(pte_mkold(pud_pte(pud)));
1085 }
1086 
1087 static inline pud_t pud_mkdirty(pud_t pud)
1088 {
1089 	return pte_pud(pte_mkdirty(pud_pte(pud)));
1090 }
1091 
1092 static inline pud_t pud_mkclean(pud_t pud)
1093 {
1094 	return pte_pud(pte_mkclean(pud_pte(pud)));
1095 }
1096 
1097 static inline pud_t pud_mkwrite(pud_t pud)
1098 {
1099 	return pte_pud(pte_mkwrite_novma(pud_pte(pud)));
1100 }
1101 
1102 static inline pud_t pud_mkhuge(pud_t pud)
1103 {
1104 	return pud;
1105 }
1106 
1107 static inline int pudp_set_access_flags(struct vm_area_struct *vma,
1108 					unsigned long address, pud_t *pudp,
1109 					pud_t entry, int dirty)
1110 {
1111 	return ptep_set_access_flags(vma, address, (pte_t *)pudp, pud_pte(entry), dirty);
1112 }
1113 
1114 static inline bool pudp_test_and_clear_young(struct vm_area_struct *vma,
1115 		unsigned long address, pud_t *pudp)
1116 {
1117 	return ptep_test_and_clear_young(vma, address, (pte_t *)pudp);
1118 }
1119 
1120 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
1121 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
1122 					    unsigned long address,  pud_t *pudp)
1123 {
1124 #ifdef CONFIG_SMP
1125 	pud_t pud = __pud(xchg(&pudp->pud, 0));
1126 #else
1127 	pud_t pud = *pudp;
1128 
1129 	pud_clear(pudp);
1130 #endif
1131 
1132 	page_table_check_pud_clear(mm, address, pud);
1133 
1134 	return pud;
1135 }
1136 
1137 static inline int pud_young(pud_t pud)
1138 {
1139 	return pte_young(pud_pte(pud));
1140 }
1141 
1142 static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
1143 					unsigned long address, pud_t *pudp)
1144 {
1145 	pte_t *ptep = (pte_t *)pudp;
1146 
1147 	update_mmu_cache(vma, address, ptep);
1148 }
1149 
1150 static inline pud_t pudp_establish(struct vm_area_struct *vma,
1151 				   unsigned long address, pud_t *pudp, pud_t pud)
1152 {
1153 	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
1154 	return __pud(atomic_long_xchg((atomic_long_t *)pudp, pud_val(pud)));
1155 }
1156 
1157 static inline pud_t pud_mkinvalid(pud_t pud)
1158 {
1159 	return __pud(pud_val(pud) & ~(_PAGE_PRESENT | _PAGE_PROT_NONE));
1160 }
1161 
1162 extern pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
1163 			     pud_t *pudp);
1164 
1165 static inline pud_t pud_modify(pud_t pud, pgprot_t newprot)
1166 {
1167 	return pte_pud(pte_modify(pud_pte(pud), newprot));
1168 }
1169 
1170 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
1171 
1172 /*
1173  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
1174  * are !pte_none() && !pte_present().
1175  *
1176  * Format of swap PTE:
1177  *	bit            0:	_PAGE_PRESENT (zero)
1178  *	bit       1 to 2:	(zero)
1179  *	bit            3:	_PAGE_SWP_SOFT_DIRTY
1180  *	bit            4:	_PAGE_SWP_UFFD
1181  *	bit            5:	_PAGE_PROT_NONE (zero)
1182  *	bit            6:	exclusive marker
1183  *	bits      7 to 11:	swap type
1184  *	bits 12 to XLEN-1:	swap offset
1185  */
1186 #define __SWP_TYPE_SHIFT	7
1187 #define __SWP_TYPE_BITS		5
1188 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
1189 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
1190 
1191 #define MAX_SWAPFILES_CHECK()	\
1192 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
1193 
1194 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
1195 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
1196 #define __swp_entry(type, offset) ((swp_entry_t) \
1197 	{ (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \
1198 	  ((offset) << __SWP_OFFSET_SHIFT) })
1199 
1200 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
1201 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
1202 
1203 static inline bool pte_swp_exclusive(pte_t pte)
1204 {
1205 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
1206 }
1207 
1208 static inline pte_t pte_swp_mkexclusive(pte_t pte)
1209 {
1210 	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
1211 }
1212 
1213 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
1214 {
1215 	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
1216 }
1217 
1218 #ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
1219 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
1220 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
1221 #endif /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
1222 
1223 /*
1224  * In the RV64 Linux scheme, we give the user half of the virtual-address space
1225  * and give the kernel the other (upper) half.
1226  */
1227 #ifdef CONFIG_64BIT
1228 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
1229 #else
1230 #define KERN_VIRT_START	FIXADDR_START
1231 #endif
1232 
1233 /*
1234  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
1235  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
1236  * Task size is:
1237  * -        0x9fc00000	(~2.5GB) for RV32.
1238  * -      0x4000000000	( 256GB) for RV64 using SV39 mmu
1239  * -    0x800000000000	( 128TB) for RV64 using SV48 mmu
1240  * - 0x100000000000000	(  64PB) for RV64 using SV57 mmu
1241  *
1242  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
1243  * Instruction Set Manual Volume II: Privileged Architecture" states that
1244  * "load and store effective addresses, which are 64bits, must have bits
1245  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
1246  * Similarly for SV57, bits 63–57 must be equal to bit 56.
1247  */
1248 #ifdef CONFIG_64BIT
1249 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
1250 
1251 #ifdef CONFIG_COMPAT
1252 #define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
1253 #define TASK_SIZE	(is_compat_task() ? \
1254 			 TASK_SIZE_32 : TASK_SIZE_64)
1255 #else
1256 #define TASK_SIZE	TASK_SIZE_64
1257 #endif
1258 
1259 #else
1260 #define TASK_SIZE	FIXADDR_START
1261 #endif
1262 
1263 #else /* CONFIG_MMU */
1264 
1265 #define PAGE_SHARED		__pgprot(0)
1266 #define PAGE_KERNEL		__pgprot(0)
1267 #define swapper_pg_dir		NULL
1268 #define TASK_SIZE		_AC(-1, UL)
1269 #define VMALLOC_START		_AC(0, UL)
1270 #define VMALLOC_END		TASK_SIZE
1271 
1272 #endif /* !CONFIG_MMU */
1273 
1274 extern char _start[];
1275 extern void *_dtb_early_va;
1276 extern uintptr_t _dtb_early_pa;
1277 #define dtb_early_va	_dtb_early_va
1278 #define dtb_early_pa	_dtb_early_pa
1279 extern u64 satp_mode;
1280 
1281 void paging_init(void);
1282 void misc_mem_init(void);
1283 
1284 /*
1285  * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
1286  * TLB flush will be required as a result of the "set". For example, use
1287  * in scenarios where it is known ahead of time that the routine is
1288  * setting non-present entries, or re-setting an existing entry to the
1289  * same value. Otherwise, use the typical "set" helpers and flush the
1290  * TLB.
1291  */
1292 #define set_p4d_safe(p4dp, p4d) \
1293 ({ \
1294 	WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
1295 	set_p4d(p4dp, p4d); \
1296 })
1297 
1298 #define set_pgd_safe(pgdp, pgd) \
1299 ({ \
1300 	WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
1301 	set_pgd(pgdp, pgd); \
1302 })
1303 #endif /* !__ASSEMBLER__ */
1304 
1305 #endif /* _ASM_RISCV_PGTABLE_H */
1306