xref: /openbmc/linux/arch/riscv/include/asm/pgtable.h (revision ff689fd21cb13098305bae3f8d0c0065df2e2fc1)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_PGTABLE_H
7 #define _ASM_RISCV_PGTABLE_H
8 
9 #include <linux/mmzone.h>
10 #include <linux/sizes.h>
11 
12 #include <asm/pgtable-bits.h>
13 
14 #ifndef CONFIG_MMU
15 #define KERNEL_LINK_ADDR	PAGE_OFFSET
16 #define KERN_VIRT_SIZE		(UL(-1))
17 #else
18 
19 #define ADDRESS_SPACE_END	(UL(-1))
20 
21 #ifdef CONFIG_64BIT
22 /* Leave 2GB for kernel and BPF at the end of the address space */
23 #define KERNEL_LINK_ADDR	(ADDRESS_SPACE_END - SZ_2G + 1)
24 #else
25 #define KERNEL_LINK_ADDR	PAGE_OFFSET
26 #endif
27 
28 /* Number of entries in the page global directory */
29 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
30 /* Number of entries in the page table */
31 #define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
32 
33 /*
34  * Half of the kernel address space (half of the entries of the page global
35  * directory) is for the direct mapping.
36  */
37 #define KERN_VIRT_SIZE          ((PTRS_PER_PGD / 2 * PGDIR_SIZE) / 2)
38 
39 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
40 #define VMALLOC_END      PAGE_OFFSET
41 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
42 
43 #define BPF_JIT_REGION_SIZE	(SZ_128M)
44 #ifdef CONFIG_64BIT
45 #define BPF_JIT_REGION_START	(BPF_JIT_REGION_END - BPF_JIT_REGION_SIZE)
46 #define BPF_JIT_REGION_END	(MODULES_END)
47 #else
48 #define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
49 #define BPF_JIT_REGION_END	(VMALLOC_END)
50 #endif
51 
52 /* Modules always live before the kernel */
53 #ifdef CONFIG_64BIT
54 /* This is used to define the end of the KASAN shadow region */
55 #define MODULES_LOWEST_VADDR	(KERNEL_LINK_ADDR - SZ_2G)
56 #define MODULES_VADDR		(PFN_ALIGN((unsigned long)&_end) - SZ_2G)
57 #define MODULES_END		(PFN_ALIGN((unsigned long)&_start))
58 #endif
59 
60 /*
61  * Roughly size the vmemmap space to be large enough to fit enough
62  * struct pages to map half the virtual address space. Then
63  * position vmemmap directly below the VMALLOC region.
64  */
65 #ifdef CONFIG_64BIT
66 #define VA_BITS		(pgtable_l5_enabled ? \
67 				57 : (pgtable_l4_enabled ? 48 : 39))
68 #else
69 #define VA_BITS		32
70 #endif
71 
72 #define VMEMMAP_SHIFT \
73 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
74 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
75 #define VMEMMAP_END	VMALLOC_START
76 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
77 
78 /*
79  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
80  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
81  */
82 #define vmemmap		((struct page *)VMEMMAP_START)
83 
84 #define PCI_IO_SIZE      SZ_16M
85 #define PCI_IO_END       VMEMMAP_START
86 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
87 
88 #define FIXADDR_TOP      PCI_IO_START
89 #ifdef CONFIG_64BIT
90 #define FIXADDR_SIZE     PMD_SIZE
91 #else
92 #define FIXADDR_SIZE     PGDIR_SIZE
93 #endif
94 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
95 
96 #endif
97 
98 #ifdef CONFIG_XIP_KERNEL
99 #define XIP_OFFSET		SZ_32M
100 #define XIP_OFFSET_MASK		(SZ_32M - 1)
101 #else
102 #define XIP_OFFSET		0
103 #endif
104 
105 #ifndef __ASSEMBLY__
106 
107 #include <asm/page.h>
108 #include <asm/tlbflush.h>
109 #include <linux/mm_types.h>
110 
111 #define __page_val_to_pfn(_val)  (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
112 
113 #ifdef CONFIG_64BIT
114 #include <asm/pgtable-64.h>
115 #else
116 #include <asm/pgtable-32.h>
117 #endif /* CONFIG_64BIT */
118 
119 #ifdef CONFIG_XIP_KERNEL
120 #define XIP_FIXUP(addr) ({							\
121 	uintptr_t __a = (uintptr_t)(addr);					\
122 	(__a >= CONFIG_XIP_PHYS_ADDR && \
123 	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
124 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
125 		__a;								\
126 	})
127 #else
128 #define XIP_FIXUP(addr)		(addr)
129 #endif /* CONFIG_XIP_KERNEL */
130 
131 struct pt_alloc_ops {
132 	pte_t *(*get_pte_virt)(phys_addr_t pa);
133 	phys_addr_t (*alloc_pte)(uintptr_t va);
134 #ifndef __PAGETABLE_PMD_FOLDED
135 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
136 	phys_addr_t (*alloc_pmd)(uintptr_t va);
137 	pud_t *(*get_pud_virt)(phys_addr_t pa);
138 	phys_addr_t (*alloc_pud)(uintptr_t va);
139 	p4d_t *(*get_p4d_virt)(phys_addr_t pa);
140 	phys_addr_t (*alloc_p4d)(uintptr_t va);
141 #endif
142 };
143 
144 extern struct pt_alloc_ops pt_ops __initdata;
145 
146 #ifdef CONFIG_MMU
147 /* Number of PGD entries that a user-mode program can use */
148 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
149 
150 /* Page protection bits */
151 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
152 
153 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
154 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
155 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
156 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
157 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
158 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
159 					 _PAGE_EXEC | _PAGE_WRITE)
160 
161 #define PAGE_COPY		PAGE_READ
162 #define PAGE_COPY_EXEC		PAGE_EXEC
163 #define PAGE_COPY_READ_EXEC	PAGE_READ_EXEC
164 #define PAGE_SHARED		PAGE_WRITE
165 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
166 
167 #define _PAGE_KERNEL		(_PAGE_READ \
168 				| _PAGE_WRITE \
169 				| _PAGE_PRESENT \
170 				| _PAGE_ACCESSED \
171 				| _PAGE_DIRTY \
172 				| _PAGE_GLOBAL)
173 
174 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
175 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
176 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
177 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
178 					 | _PAGE_EXEC)
179 
180 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
181 
182 #define _PAGE_IOREMAP	((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_IO)
183 #define PAGE_KERNEL_IO		__pgprot(_PAGE_IOREMAP)
184 
185 extern pgd_t swapper_pg_dir[];
186 
187 /* MAP_PRIVATE permissions: xwr (copy-on-write) */
188 #define __P000	PAGE_NONE
189 #define __P001	PAGE_READ
190 #define __P010	PAGE_COPY
191 #define __P011	PAGE_COPY
192 #define __P100	PAGE_EXEC
193 #define __P101	PAGE_READ_EXEC
194 #define __P110	PAGE_COPY_EXEC
195 #define __P111	PAGE_COPY_READ_EXEC
196 
197 /* MAP_SHARED permissions: xwr */
198 #define __S000	PAGE_NONE
199 #define __S001	PAGE_READ
200 #define __S010	PAGE_SHARED
201 #define __S011	PAGE_SHARED
202 #define __S100	PAGE_EXEC
203 #define __S101	PAGE_READ_EXEC
204 #define __S110	PAGE_SHARED_EXEC
205 #define __S111	PAGE_SHARED_EXEC
206 
207 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
208 static inline int pmd_present(pmd_t pmd)
209 {
210 	/*
211 	 * Checking for _PAGE_LEAF is needed too because:
212 	 * When splitting a THP, split_huge_page() will temporarily clear
213 	 * the present bit, in this situation, pmd_present() and
214 	 * pmd_trans_huge() still needs to return true.
215 	 */
216 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
217 }
218 #else
219 static inline int pmd_present(pmd_t pmd)
220 {
221 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
222 }
223 #endif
224 
225 static inline int pmd_none(pmd_t pmd)
226 {
227 	return (pmd_val(pmd) == 0);
228 }
229 
230 static inline int pmd_bad(pmd_t pmd)
231 {
232 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
233 }
234 
235 #define pmd_leaf	pmd_leaf
236 static inline int pmd_leaf(pmd_t pmd)
237 {
238 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
239 }
240 
241 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
242 {
243 	*pmdp = pmd;
244 }
245 
246 static inline void pmd_clear(pmd_t *pmdp)
247 {
248 	set_pmd(pmdp, __pmd(0));
249 }
250 
251 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
252 {
253 	return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
254 }
255 
256 static inline unsigned long _pgd_pfn(pgd_t pgd)
257 {
258 	return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
259 }
260 
261 static inline struct page *pmd_page(pmd_t pmd)
262 {
263 	return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
264 }
265 
266 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
267 {
268 	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
269 }
270 
271 static inline pte_t pmd_pte(pmd_t pmd)
272 {
273 	return __pte(pmd_val(pmd));
274 }
275 
276 static inline pte_t pud_pte(pud_t pud)
277 {
278 	return __pte(pud_val(pud));
279 }
280 
281 /* Yields the page frame number (PFN) of a page table entry */
282 static inline unsigned long pte_pfn(pte_t pte)
283 {
284 	return __page_val_to_pfn(pte_val(pte));
285 }
286 
287 #define pte_page(x)     pfn_to_page(pte_pfn(x))
288 
289 /* Constructs a page table entry */
290 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
291 {
292 	return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
293 }
294 
295 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
296 
297 static inline int pte_present(pte_t pte)
298 {
299 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
300 }
301 
302 static inline int pte_none(pte_t pte)
303 {
304 	return (pte_val(pte) == 0);
305 }
306 
307 static inline int pte_write(pte_t pte)
308 {
309 	return pte_val(pte) & _PAGE_WRITE;
310 }
311 
312 static inline int pte_exec(pte_t pte)
313 {
314 	return pte_val(pte) & _PAGE_EXEC;
315 }
316 
317 static inline int pte_huge(pte_t pte)
318 {
319 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
320 }
321 
322 static inline int pte_dirty(pte_t pte)
323 {
324 	return pte_val(pte) & _PAGE_DIRTY;
325 }
326 
327 static inline int pte_young(pte_t pte)
328 {
329 	return pte_val(pte) & _PAGE_ACCESSED;
330 }
331 
332 static inline int pte_special(pte_t pte)
333 {
334 	return pte_val(pte) & _PAGE_SPECIAL;
335 }
336 
337 /* static inline pte_t pte_rdprotect(pte_t pte) */
338 
339 static inline pte_t pte_wrprotect(pte_t pte)
340 {
341 	return __pte(pte_val(pte) & ~(_PAGE_WRITE));
342 }
343 
344 /* static inline pte_t pte_mkread(pte_t pte) */
345 
346 static inline pte_t pte_mkwrite(pte_t pte)
347 {
348 	return __pte(pte_val(pte) | _PAGE_WRITE);
349 }
350 
351 /* static inline pte_t pte_mkexec(pte_t pte) */
352 
353 static inline pte_t pte_mkdirty(pte_t pte)
354 {
355 	return __pte(pte_val(pte) | _PAGE_DIRTY);
356 }
357 
358 static inline pte_t pte_mkclean(pte_t pte)
359 {
360 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
361 }
362 
363 static inline pte_t pte_mkyoung(pte_t pte)
364 {
365 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
366 }
367 
368 static inline pte_t pte_mkold(pte_t pte)
369 {
370 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
371 }
372 
373 static inline pte_t pte_mkspecial(pte_t pte)
374 {
375 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
376 }
377 
378 static inline pte_t pte_mkhuge(pte_t pte)
379 {
380 	return pte;
381 }
382 
383 #ifdef CONFIG_NUMA_BALANCING
384 /*
385  * See the comment in include/asm-generic/pgtable.h
386  */
387 static inline int pte_protnone(pte_t pte)
388 {
389 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
390 }
391 
392 static inline int pmd_protnone(pmd_t pmd)
393 {
394 	return pte_protnone(pmd_pte(pmd));
395 }
396 #endif
397 
398 /* Modify page protection bits */
399 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
400 {
401 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
402 }
403 
404 #define pgd_ERROR(e) \
405 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
406 
407 
408 /* Commit new configuration to MMU hardware */
409 static inline void update_mmu_cache(struct vm_area_struct *vma,
410 	unsigned long address, pte_t *ptep)
411 {
412 	/*
413 	 * The kernel assumes that TLBs don't cache invalid entries, but
414 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
415 	 * cache flush; it is necessary even after writing invalid entries.
416 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
417 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
418 	 */
419 	local_flush_tlb_page(address);
420 }
421 
422 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
423 		unsigned long address, pmd_t *pmdp)
424 {
425 	pte_t *ptep = (pte_t *)pmdp;
426 
427 	update_mmu_cache(vma, address, ptep);
428 }
429 
430 #define __HAVE_ARCH_PTE_SAME
431 static inline int pte_same(pte_t pte_a, pte_t pte_b)
432 {
433 	return pte_val(pte_a) == pte_val(pte_b);
434 }
435 
436 /*
437  * Certain architectures need to do special things when PTEs within
438  * a page table are directly modified.  Thus, the following hook is
439  * made available.
440  */
441 static inline void set_pte(pte_t *ptep, pte_t pteval)
442 {
443 	*ptep = pteval;
444 }
445 
446 void flush_icache_pte(pte_t pte);
447 
448 static inline void set_pte_at(struct mm_struct *mm,
449 	unsigned long addr, pte_t *ptep, pte_t pteval)
450 {
451 	if (pte_present(pteval) && pte_exec(pteval))
452 		flush_icache_pte(pteval);
453 
454 	set_pte(ptep, pteval);
455 }
456 
457 static inline void pte_clear(struct mm_struct *mm,
458 	unsigned long addr, pte_t *ptep)
459 {
460 	set_pte_at(mm, addr, ptep, __pte(0));
461 }
462 
463 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
464 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
465 					unsigned long address, pte_t *ptep,
466 					pte_t entry, int dirty)
467 {
468 	if (!pte_same(*ptep, entry))
469 		set_pte_at(vma->vm_mm, address, ptep, entry);
470 	/*
471 	 * update_mmu_cache will unconditionally execute, handling both
472 	 * the case that the PTE changed and the spurious fault case.
473 	 */
474 	return true;
475 }
476 
477 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
478 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
479 				       unsigned long address, pte_t *ptep)
480 {
481 	return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
482 }
483 
484 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
485 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
486 					    unsigned long address,
487 					    pte_t *ptep)
488 {
489 	if (!pte_young(*ptep))
490 		return 0;
491 	return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
492 }
493 
494 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
495 static inline void ptep_set_wrprotect(struct mm_struct *mm,
496 				      unsigned long address, pte_t *ptep)
497 {
498 	atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
499 }
500 
501 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
502 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
503 					 unsigned long address, pte_t *ptep)
504 {
505 	/*
506 	 * This comment is borrowed from x86, but applies equally to RISC-V:
507 	 *
508 	 * Clearing the accessed bit without a TLB flush
509 	 * doesn't cause data corruption. [ It could cause incorrect
510 	 * page aging and the (mistaken) reclaim of hot pages, but the
511 	 * chance of that should be relatively low. ]
512 	 *
513 	 * So as a performance optimization don't flush the TLB when
514 	 * clearing the accessed bit, it will eventually be flushed by
515 	 * a context switch or a VM operation anyway. [ In the rare
516 	 * event of it not getting flushed for a long time the delay
517 	 * shouldn't really matter because there's no real memory
518 	 * pressure for swapout to react to. ]
519 	 */
520 	return ptep_test_and_clear_young(vma, address, ptep);
521 }
522 
523 #define pgprot_noncached pgprot_noncached
524 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
525 {
526 	unsigned long prot = pgprot_val(_prot);
527 
528 	prot &= ~_PAGE_MTMASK;
529 	prot |= _PAGE_IO;
530 
531 	return __pgprot(prot);
532 }
533 
534 #define pgprot_writecombine pgprot_writecombine
535 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
536 {
537 	unsigned long prot = pgprot_val(_prot);
538 
539 	prot &= ~_PAGE_MTMASK;
540 	prot |= _PAGE_NOCACHE;
541 
542 	return __pgprot(prot);
543 }
544 
545 /*
546  * THP functions
547  */
548 static inline pmd_t pte_pmd(pte_t pte)
549 {
550 	return __pmd(pte_val(pte));
551 }
552 
553 static inline pmd_t pmd_mkhuge(pmd_t pmd)
554 {
555 	return pmd;
556 }
557 
558 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
559 {
560 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
561 }
562 
563 #define __pmd_to_phys(pmd)  (pmd_val(pmd) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
564 
565 static inline unsigned long pmd_pfn(pmd_t pmd)
566 {
567 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
568 }
569 
570 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
571 {
572 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
573 }
574 
575 #define pmd_write pmd_write
576 static inline int pmd_write(pmd_t pmd)
577 {
578 	return pte_write(pmd_pte(pmd));
579 }
580 
581 static inline int pmd_dirty(pmd_t pmd)
582 {
583 	return pte_dirty(pmd_pte(pmd));
584 }
585 
586 static inline int pmd_young(pmd_t pmd)
587 {
588 	return pte_young(pmd_pte(pmd));
589 }
590 
591 static inline pmd_t pmd_mkold(pmd_t pmd)
592 {
593 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
594 }
595 
596 static inline pmd_t pmd_mkyoung(pmd_t pmd)
597 {
598 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
599 }
600 
601 static inline pmd_t pmd_mkwrite(pmd_t pmd)
602 {
603 	return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
604 }
605 
606 static inline pmd_t pmd_wrprotect(pmd_t pmd)
607 {
608 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
609 }
610 
611 static inline pmd_t pmd_mkclean(pmd_t pmd)
612 {
613 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
614 }
615 
616 static inline pmd_t pmd_mkdirty(pmd_t pmd)
617 {
618 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
619 }
620 
621 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
622 				pmd_t *pmdp, pmd_t pmd)
623 {
624 	return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
625 }
626 
627 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
628 				pud_t *pudp, pud_t pud)
629 {
630 	return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
631 }
632 
633 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
634 static inline int pmd_trans_huge(pmd_t pmd)
635 {
636 	return pmd_leaf(pmd);
637 }
638 
639 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
640 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
641 					unsigned long address, pmd_t *pmdp,
642 					pmd_t entry, int dirty)
643 {
644 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
645 }
646 
647 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
648 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
649 					unsigned long address, pmd_t *pmdp)
650 {
651 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
652 }
653 
654 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
655 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
656 					unsigned long address, pmd_t *pmdp)
657 {
658 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
659 }
660 
661 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
662 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
663 					unsigned long address, pmd_t *pmdp)
664 {
665 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
666 }
667 
668 #define pmdp_establish pmdp_establish
669 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
670 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
671 {
672 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
673 }
674 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
675 
676 /*
677  * Encode and decode a swap entry
678  *
679  * Format of swap PTE:
680  *	bit            0:	_PAGE_PRESENT (zero)
681  *	bit       1 to 3:       _PAGE_LEAF (zero)
682  *	bit            5:	_PAGE_PROT_NONE (zero)
683  *	bits      6 to 10:	swap type
684  *	bits 10 to XLEN-1:	swap offset
685  */
686 #define __SWP_TYPE_SHIFT	6
687 #define __SWP_TYPE_BITS		5
688 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
689 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
690 
691 #define MAX_SWAPFILES_CHECK()	\
692 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
693 
694 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
695 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
696 #define __swp_entry(type, offset) ((swp_entry_t) \
697 	{ ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
698 
699 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
700 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
701 
702 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
703 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
704 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
705 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
706 
707 /*
708  * In the RV64 Linux scheme, we give the user half of the virtual-address space
709  * and give the kernel the other (upper) half.
710  */
711 #ifdef CONFIG_64BIT
712 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
713 #else
714 #define KERN_VIRT_START	FIXADDR_START
715 #endif
716 
717 /*
718  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
719  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
720  * Task size is:
721  * -     0x9fc00000 (~2.5GB) for RV32.
722  * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
723  * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
724  *
725  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
726  * Instruction Set Manual Volume II: Privileged Architecture" states that
727  * "load and store effective addresses, which are 64bits, must have bits
728  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
729  */
730 #ifdef CONFIG_64BIT
731 #define TASK_SIZE      (PGDIR_SIZE * PTRS_PER_PGD / 2)
732 #define TASK_SIZE_MIN  (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
733 #else
734 #define TASK_SIZE	FIXADDR_START
735 #define TASK_SIZE_MIN	TASK_SIZE
736 #endif
737 
738 #else /* CONFIG_MMU */
739 
740 #define PAGE_SHARED		__pgprot(0)
741 #define PAGE_KERNEL		__pgprot(0)
742 #define swapper_pg_dir		NULL
743 #define TASK_SIZE		0xffffffffUL
744 #define VMALLOC_START		0
745 #define VMALLOC_END		TASK_SIZE
746 
747 #endif /* !CONFIG_MMU */
748 
749 #define kern_addr_valid(addr)   (1) /* FIXME */
750 
751 extern char _start[];
752 extern void *_dtb_early_va;
753 extern uintptr_t _dtb_early_pa;
754 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
755 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
756 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
757 #else
758 #define dtb_early_va	_dtb_early_va
759 #define dtb_early_pa	_dtb_early_pa
760 #endif /* CONFIG_XIP_KERNEL */
761 extern u64 satp_mode;
762 extern bool pgtable_l4_enabled;
763 
764 void paging_init(void);
765 void misc_mem_init(void);
766 
767 /*
768  * ZERO_PAGE is a global shared page that is always zero,
769  * used for zero-mapped memory areas, etc.
770  */
771 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
772 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
773 
774 #endif /* !__ASSEMBLY__ */
775 
776 #endif /* _ASM_RISCV_PGTABLE_H */
777