xref: /openbmc/linux/arch/riscv/include/asm/pgtable.h (revision 0aa6b294)
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 #else
17 
18 #define ADDRESS_SPACE_END	(UL(-1))
19 
20 #ifdef CONFIG_64BIT
21 /* Leave 2GB for kernel and BPF at the end of the address space */
22 #define KERNEL_LINK_ADDR	(ADDRESS_SPACE_END - SZ_2G + 1)
23 #else
24 #define KERNEL_LINK_ADDR	PAGE_OFFSET
25 #endif
26 
27 /* Number of entries in the page global directory */
28 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
29 /* Number of entries in the page table */
30 #define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
31 
32 /*
33  * Half of the kernel address space (half of the entries of the page global
34  * directory) is for the direct mapping.
35  */
36 #define KERN_VIRT_SIZE          ((PTRS_PER_PGD / 2 * PGDIR_SIZE) / 2)
37 
38 #define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
39 #define VMALLOC_END      PAGE_OFFSET
40 #define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
41 
42 #define BPF_JIT_REGION_SIZE	(SZ_128M)
43 #ifdef CONFIG_64BIT
44 #define BPF_JIT_REGION_START	(BPF_JIT_REGION_END - BPF_JIT_REGION_SIZE)
45 #define BPF_JIT_REGION_END	(MODULES_END)
46 #else
47 #define BPF_JIT_REGION_START	(PAGE_OFFSET - BPF_JIT_REGION_SIZE)
48 #define BPF_JIT_REGION_END	(VMALLOC_END)
49 #endif
50 
51 /* Modules always live before the kernel */
52 #ifdef CONFIG_64BIT
53 /* This is used to define the end of the KASAN shadow region */
54 #define MODULES_LOWEST_VADDR	(KERNEL_LINK_ADDR - SZ_2G)
55 #define MODULES_VADDR		(PFN_ALIGN((unsigned long)&_end) - SZ_2G)
56 #define MODULES_END		(PFN_ALIGN((unsigned long)&_start))
57 #endif
58 
59 /*
60  * Roughly size the vmemmap space to be large enough to fit enough
61  * struct pages to map half the virtual address space. Then
62  * position vmemmap directly below the VMALLOC region.
63  */
64 #ifdef CONFIG_64BIT
65 #define VA_BITS		(pgtable_l4_enabled ? 48 : 39)
66 #else
67 #define VA_BITS		32
68 #endif
69 
70 #define VMEMMAP_SHIFT \
71 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
72 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
73 #define VMEMMAP_END	VMALLOC_START
74 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
75 
76 /*
77  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
78  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
79  */
80 #define vmemmap		((struct page *)VMEMMAP_START)
81 
82 #define PCI_IO_SIZE      SZ_16M
83 #define PCI_IO_END       VMEMMAP_START
84 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
85 
86 #define FIXADDR_TOP      PCI_IO_START
87 #ifdef CONFIG_64BIT
88 #define FIXADDR_SIZE     PMD_SIZE
89 #else
90 #define FIXADDR_SIZE     PGDIR_SIZE
91 #endif
92 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
93 
94 #endif
95 
96 #ifdef CONFIG_XIP_KERNEL
97 #define XIP_OFFSET		SZ_32M
98 #define XIP_OFFSET_MASK		(SZ_32M - 1)
99 #else
100 #define XIP_OFFSET		0
101 #endif
102 
103 #ifndef __ASSEMBLY__
104 
105 #include <asm-generic/pgtable-nop4d.h>
106 #include <asm/page.h>
107 #include <asm/tlbflush.h>
108 #include <linux/mm_types.h>
109 
110 #ifdef CONFIG_64BIT
111 #include <asm/pgtable-64.h>
112 #else
113 #include <asm/pgtable-32.h>
114 #endif /* CONFIG_64BIT */
115 
116 #ifdef CONFIG_XIP_KERNEL
117 #define XIP_FIXUP(addr) ({							\
118 	uintptr_t __a = (uintptr_t)(addr);					\
119 	(__a >= CONFIG_XIP_PHYS_ADDR && \
120 	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
121 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
122 		__a;								\
123 	})
124 #else
125 #define XIP_FIXUP(addr)		(addr)
126 #endif /* CONFIG_XIP_KERNEL */
127 
128 struct pt_alloc_ops {
129 	pte_t *(*get_pte_virt)(phys_addr_t pa);
130 	phys_addr_t (*alloc_pte)(uintptr_t va);
131 #ifndef __PAGETABLE_PMD_FOLDED
132 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
133 	phys_addr_t (*alloc_pmd)(uintptr_t va);
134 	pud_t *(*get_pud_virt)(phys_addr_t pa);
135 	phys_addr_t (*alloc_pud)(uintptr_t va);
136 #endif
137 };
138 
139 extern struct pt_alloc_ops pt_ops __initdata;
140 
141 #ifdef CONFIG_MMU
142 /* Number of PGD entries that a user-mode program can use */
143 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
144 
145 /* Page protection bits */
146 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
147 
148 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
149 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
150 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
151 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
152 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
153 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
154 					 _PAGE_EXEC | _PAGE_WRITE)
155 
156 #define PAGE_COPY		PAGE_READ
157 #define PAGE_COPY_EXEC		PAGE_EXEC
158 #define PAGE_COPY_READ_EXEC	PAGE_READ_EXEC
159 #define PAGE_SHARED		PAGE_WRITE
160 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
161 
162 #define _PAGE_KERNEL		(_PAGE_READ \
163 				| _PAGE_WRITE \
164 				| _PAGE_PRESENT \
165 				| _PAGE_ACCESSED \
166 				| _PAGE_DIRTY \
167 				| _PAGE_GLOBAL)
168 
169 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
170 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
171 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
172 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
173 					 | _PAGE_EXEC)
174 
175 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
176 
177 /*
178  * The RISC-V ISA doesn't yet specify how to query or modify PMAs, so we can't
179  * change the properties of memory regions.
180  */
181 #define _PAGE_IOREMAP _PAGE_KERNEL
182 
183 extern pgd_t swapper_pg_dir[];
184 
185 /* MAP_PRIVATE permissions: xwr (copy-on-write) */
186 #define __P000	PAGE_NONE
187 #define __P001	PAGE_READ
188 #define __P010	PAGE_COPY
189 #define __P011	PAGE_COPY
190 #define __P100	PAGE_EXEC
191 #define __P101	PAGE_READ_EXEC
192 #define __P110	PAGE_COPY_EXEC
193 #define __P111	PAGE_COPY_READ_EXEC
194 
195 /* MAP_SHARED permissions: xwr */
196 #define __S000	PAGE_NONE
197 #define __S001	PAGE_READ
198 #define __S010	PAGE_SHARED
199 #define __S011	PAGE_SHARED
200 #define __S100	PAGE_EXEC
201 #define __S101	PAGE_READ_EXEC
202 #define __S110	PAGE_SHARED_EXEC
203 #define __S111	PAGE_SHARED_EXEC
204 
205 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
206 static inline int pmd_present(pmd_t pmd)
207 {
208 	/*
209 	 * Checking for _PAGE_LEAF is needed too because:
210 	 * When splitting a THP, split_huge_page() will temporarily clear
211 	 * the present bit, in this situation, pmd_present() and
212 	 * pmd_trans_huge() still needs to return true.
213 	 */
214 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
215 }
216 #else
217 static inline int pmd_present(pmd_t pmd)
218 {
219 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
220 }
221 #endif
222 
223 static inline int pmd_none(pmd_t pmd)
224 {
225 	return (pmd_val(pmd) == 0);
226 }
227 
228 static inline int pmd_bad(pmd_t pmd)
229 {
230 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
231 }
232 
233 #define pmd_leaf	pmd_leaf
234 static inline int pmd_leaf(pmd_t pmd)
235 {
236 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
237 }
238 
239 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
240 {
241 	*pmdp = pmd;
242 }
243 
244 static inline void pmd_clear(pmd_t *pmdp)
245 {
246 	set_pmd(pmdp, __pmd(0));
247 }
248 
249 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
250 {
251 	return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
252 }
253 
254 static inline unsigned long _pgd_pfn(pgd_t pgd)
255 {
256 	return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
257 }
258 
259 static inline struct page *pmd_page(pmd_t pmd)
260 {
261 	return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
262 }
263 
264 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
265 {
266 	return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
267 }
268 
269 static inline pte_t pmd_pte(pmd_t pmd)
270 {
271 	return __pte(pmd_val(pmd));
272 }
273 
274 static inline pte_t pud_pte(pud_t pud)
275 {
276 	return __pte(pud_val(pud));
277 }
278 
279 /* Yields the page frame number (PFN) of a page table entry */
280 static inline unsigned long pte_pfn(pte_t pte)
281 {
282 	return (pte_val(pte) >> _PAGE_PFN_SHIFT);
283 }
284 
285 #define pte_page(x)     pfn_to_page(pte_pfn(x))
286 
287 /* Constructs a page table entry */
288 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
289 {
290 	return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
291 }
292 
293 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
294 
295 static inline int pte_present(pte_t pte)
296 {
297 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
298 }
299 
300 static inline int pte_none(pte_t pte)
301 {
302 	return (pte_val(pte) == 0);
303 }
304 
305 static inline int pte_write(pte_t pte)
306 {
307 	return pte_val(pte) & _PAGE_WRITE;
308 }
309 
310 static inline int pte_exec(pte_t pte)
311 {
312 	return pte_val(pte) & _PAGE_EXEC;
313 }
314 
315 static inline int pte_huge(pte_t pte)
316 {
317 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
318 }
319 
320 static inline int pte_dirty(pte_t pte)
321 {
322 	return pte_val(pte) & _PAGE_DIRTY;
323 }
324 
325 static inline int pte_young(pte_t pte)
326 {
327 	return pte_val(pte) & _PAGE_ACCESSED;
328 }
329 
330 static inline int pte_special(pte_t pte)
331 {
332 	return pte_val(pte) & _PAGE_SPECIAL;
333 }
334 
335 /* static inline pte_t pte_rdprotect(pte_t pte) */
336 
337 static inline pte_t pte_wrprotect(pte_t pte)
338 {
339 	return __pte(pte_val(pte) & ~(_PAGE_WRITE));
340 }
341 
342 /* static inline pte_t pte_mkread(pte_t pte) */
343 
344 static inline pte_t pte_mkwrite(pte_t pte)
345 {
346 	return __pte(pte_val(pte) | _PAGE_WRITE);
347 }
348 
349 /* static inline pte_t pte_mkexec(pte_t pte) */
350 
351 static inline pte_t pte_mkdirty(pte_t pte)
352 {
353 	return __pte(pte_val(pte) | _PAGE_DIRTY);
354 }
355 
356 static inline pte_t pte_mkclean(pte_t pte)
357 {
358 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
359 }
360 
361 static inline pte_t pte_mkyoung(pte_t pte)
362 {
363 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
364 }
365 
366 static inline pte_t pte_mkold(pte_t pte)
367 {
368 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
369 }
370 
371 static inline pte_t pte_mkspecial(pte_t pte)
372 {
373 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
374 }
375 
376 static inline pte_t pte_mkhuge(pte_t pte)
377 {
378 	return pte;
379 }
380 
381 #ifdef CONFIG_NUMA_BALANCING
382 /*
383  * See the comment in include/asm-generic/pgtable.h
384  */
385 static inline int pte_protnone(pte_t pte)
386 {
387 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
388 }
389 
390 static inline int pmd_protnone(pmd_t pmd)
391 {
392 	return pte_protnone(pmd_pte(pmd));
393 }
394 #endif
395 
396 /* Modify page protection bits */
397 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
398 {
399 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
400 }
401 
402 #define pgd_ERROR(e) \
403 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
404 
405 
406 /* Commit new configuration to MMU hardware */
407 static inline void update_mmu_cache(struct vm_area_struct *vma,
408 	unsigned long address, pte_t *ptep)
409 {
410 	/*
411 	 * The kernel assumes that TLBs don't cache invalid entries, but
412 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
413 	 * cache flush; it is necessary even after writing invalid entries.
414 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
415 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
416 	 */
417 	local_flush_tlb_page(address);
418 }
419 
420 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
421 		unsigned long address, pmd_t *pmdp)
422 {
423 	pte_t *ptep = (pte_t *)pmdp;
424 
425 	update_mmu_cache(vma, address, ptep);
426 }
427 
428 #define __HAVE_ARCH_PTE_SAME
429 static inline int pte_same(pte_t pte_a, pte_t pte_b)
430 {
431 	return pte_val(pte_a) == pte_val(pte_b);
432 }
433 
434 /*
435  * Certain architectures need to do special things when PTEs within
436  * a page table are directly modified.  Thus, the following hook is
437  * made available.
438  */
439 static inline void set_pte(pte_t *ptep, pte_t pteval)
440 {
441 	*ptep = pteval;
442 }
443 
444 void flush_icache_pte(pte_t pte);
445 
446 static inline void set_pte_at(struct mm_struct *mm,
447 	unsigned long addr, pte_t *ptep, pte_t pteval)
448 {
449 	if (pte_present(pteval) && pte_exec(pteval))
450 		flush_icache_pte(pteval);
451 
452 	set_pte(ptep, pteval);
453 }
454 
455 static inline void pte_clear(struct mm_struct *mm,
456 	unsigned long addr, pte_t *ptep)
457 {
458 	set_pte_at(mm, addr, ptep, __pte(0));
459 }
460 
461 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
462 static inline int ptep_set_access_flags(struct vm_area_struct *vma,
463 					unsigned long address, pte_t *ptep,
464 					pte_t entry, int dirty)
465 {
466 	if (!pte_same(*ptep, entry))
467 		set_pte_at(vma->vm_mm, address, ptep, entry);
468 	/*
469 	 * update_mmu_cache will unconditionally execute, handling both
470 	 * the case that the PTE changed and the spurious fault case.
471 	 */
472 	return true;
473 }
474 
475 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
476 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
477 				       unsigned long address, pte_t *ptep)
478 {
479 	return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
480 }
481 
482 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
483 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
484 					    unsigned long address,
485 					    pte_t *ptep)
486 {
487 	if (!pte_young(*ptep))
488 		return 0;
489 	return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
490 }
491 
492 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
493 static inline void ptep_set_wrprotect(struct mm_struct *mm,
494 				      unsigned long address, pte_t *ptep)
495 {
496 	atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
497 }
498 
499 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
500 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
501 					 unsigned long address, pte_t *ptep)
502 {
503 	/*
504 	 * This comment is borrowed from x86, but applies equally to RISC-V:
505 	 *
506 	 * Clearing the accessed bit without a TLB flush
507 	 * doesn't cause data corruption. [ It could cause incorrect
508 	 * page aging and the (mistaken) reclaim of hot pages, but the
509 	 * chance of that should be relatively low. ]
510 	 *
511 	 * So as a performance optimization don't flush the TLB when
512 	 * clearing the accessed bit, it will eventually be flushed by
513 	 * a context switch or a VM operation anyway. [ In the rare
514 	 * event of it not getting flushed for a long time the delay
515 	 * shouldn't really matter because there's no real memory
516 	 * pressure for swapout to react to. ]
517 	 */
518 	return ptep_test_and_clear_young(vma, address, ptep);
519 }
520 
521 /*
522  * THP functions
523  */
524 static inline pmd_t pte_pmd(pte_t pte)
525 {
526 	return __pmd(pte_val(pte));
527 }
528 
529 static inline pmd_t pmd_mkhuge(pmd_t pmd)
530 {
531 	return pmd;
532 }
533 
534 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
535 {
536 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
537 }
538 
539 #define __pmd_to_phys(pmd)  (pmd_val(pmd) >> _PAGE_PFN_SHIFT << PAGE_SHIFT)
540 
541 static inline unsigned long pmd_pfn(pmd_t pmd)
542 {
543 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
544 }
545 
546 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
547 {
548 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
549 }
550 
551 #define pmd_write pmd_write
552 static inline int pmd_write(pmd_t pmd)
553 {
554 	return pte_write(pmd_pte(pmd));
555 }
556 
557 static inline int pmd_dirty(pmd_t pmd)
558 {
559 	return pte_dirty(pmd_pte(pmd));
560 }
561 
562 static inline int pmd_young(pmd_t pmd)
563 {
564 	return pte_young(pmd_pte(pmd));
565 }
566 
567 static inline pmd_t pmd_mkold(pmd_t pmd)
568 {
569 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
570 }
571 
572 static inline pmd_t pmd_mkyoung(pmd_t pmd)
573 {
574 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
575 }
576 
577 static inline pmd_t pmd_mkwrite(pmd_t pmd)
578 {
579 	return pte_pmd(pte_mkwrite(pmd_pte(pmd)));
580 }
581 
582 static inline pmd_t pmd_wrprotect(pmd_t pmd)
583 {
584 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
585 }
586 
587 static inline pmd_t pmd_mkclean(pmd_t pmd)
588 {
589 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
590 }
591 
592 static inline pmd_t pmd_mkdirty(pmd_t pmd)
593 {
594 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
595 }
596 
597 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
598 				pmd_t *pmdp, pmd_t pmd)
599 {
600 	return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));
601 }
602 
603 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
604 				pud_t *pudp, pud_t pud)
605 {
606 	return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));
607 }
608 
609 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
610 static inline int pmd_trans_huge(pmd_t pmd)
611 {
612 	return pmd_leaf(pmd);
613 }
614 
615 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
616 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
617 					unsigned long address, pmd_t *pmdp,
618 					pmd_t entry, int dirty)
619 {
620 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
621 }
622 
623 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
624 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
625 					unsigned long address, pmd_t *pmdp)
626 {
627 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
628 }
629 
630 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
631 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
632 					unsigned long address, pmd_t *pmdp)
633 {
634 	return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
635 }
636 
637 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
638 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
639 					unsigned long address, pmd_t *pmdp)
640 {
641 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
642 }
643 
644 #define pmdp_establish pmdp_establish
645 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
646 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
647 {
648 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
649 }
650 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
651 
652 /*
653  * Encode and decode a swap entry
654  *
655  * Format of swap PTE:
656  *	bit            0:	_PAGE_PRESENT (zero)
657  *	bit       1 to 3:       _PAGE_LEAF (zero)
658  *	bit            5:	_PAGE_PROT_NONE (zero)
659  *	bits      6 to 10:	swap type
660  *	bits 10 to XLEN-1:	swap offset
661  */
662 #define __SWP_TYPE_SHIFT	6
663 #define __SWP_TYPE_BITS		5
664 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
665 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
666 
667 #define MAX_SWAPFILES_CHECK()	\
668 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
669 
670 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
671 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
672 #define __swp_entry(type, offset) ((swp_entry_t) \
673 	{ ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
674 
675 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
676 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
677 
678 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
679 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
680 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
681 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
682 
683 /*
684  * In the RV64 Linux scheme, we give the user half of the virtual-address space
685  * and give the kernel the other (upper) half.
686  */
687 #ifdef CONFIG_64BIT
688 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
689 #else
690 #define KERN_VIRT_START	FIXADDR_START
691 #endif
692 
693 /*
694  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
695  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
696  * Task size is:
697  * -     0x9fc00000 (~2.5GB) for RV32.
698  * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
699  * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
700  *
701  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
702  * Instruction Set Manual Volume II: Privileged Architecture" states that
703  * "load and store effective addresses, which are 64bits, must have bits
704  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
705  */
706 #ifdef CONFIG_64BIT
707 #define TASK_SIZE      (PGDIR_SIZE * PTRS_PER_PGD / 2)
708 #define TASK_SIZE_MIN  (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
709 #else
710 #define TASK_SIZE	FIXADDR_START
711 #define TASK_SIZE_MIN	TASK_SIZE
712 #endif
713 
714 #else /* CONFIG_MMU */
715 
716 #define PAGE_SHARED		__pgprot(0)
717 #define PAGE_KERNEL		__pgprot(0)
718 #define swapper_pg_dir		NULL
719 #define TASK_SIZE		0xffffffffUL
720 #define VMALLOC_START		0
721 #define VMALLOC_END		TASK_SIZE
722 
723 #endif /* !CONFIG_MMU */
724 
725 #define kern_addr_valid(addr)   (1) /* FIXME */
726 
727 extern char _start[];
728 extern void *_dtb_early_va;
729 extern uintptr_t _dtb_early_pa;
730 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
731 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
732 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
733 #else
734 #define dtb_early_va	_dtb_early_va
735 #define dtb_early_pa	_dtb_early_pa
736 #endif /* CONFIG_XIP_KERNEL */
737 extern u64 satp_mode;
738 extern bool pgtable_l4_enabled;
739 
740 void paging_init(void);
741 void misc_mem_init(void);
742 
743 /*
744  * ZERO_PAGE is a global shared page that is always zero,
745  * used for zero-mapped memory areas, etc.
746  */
747 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
748 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
749 
750 #endif /* !__ASSEMBLY__ */
751 
752 #endif /* _ASM_RISCV_PGTABLE_H */
753