xref: /linux/arch/riscv/include/asm/pgtable.h (revision a3a02a52bcfcbcc4a637d4b68bf1bc391c9fad02)
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 (1/4 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 #else
59 #define MODULES_VADDR		VMALLOC_START
60 #define MODULES_END		VMALLOC_END
61 #endif
62 
63 /*
64  * Roughly size the vmemmap space to be large enough to fit enough
65  * struct pages to map half the virtual address space. Then
66  * position vmemmap directly below the VMALLOC region.
67  */
68 #define VA_BITS_SV32 32
69 #ifdef CONFIG_64BIT
70 #define VA_BITS_SV39 39
71 #define VA_BITS_SV48 48
72 #define VA_BITS_SV57 57
73 
74 #define VA_BITS		(pgtable_l5_enabled ? \
75 				VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39))
76 #else
77 #define VA_BITS		VA_BITS_SV32
78 #endif
79 
80 #define VMEMMAP_SHIFT \
81 	(VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
82 #define VMEMMAP_SIZE	BIT(VMEMMAP_SHIFT)
83 #define VMEMMAP_END	VMALLOC_START
84 #define VMEMMAP_START	(VMALLOC_START - VMEMMAP_SIZE)
85 
86 /*
87  * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
88  * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
89  */
90 #define vmemmap		((struct page *)VMEMMAP_START - (phys_ram_base >> PAGE_SHIFT))
91 
92 #define PCI_IO_SIZE      SZ_16M
93 #define PCI_IO_END       VMEMMAP_START
94 #define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
95 
96 #define FIXADDR_TOP      PCI_IO_START
97 #ifdef CONFIG_64BIT
98 #define MAX_FDT_SIZE	 PMD_SIZE
99 #define FIX_FDT_SIZE	 (MAX_FDT_SIZE + SZ_2M)
100 #define FIXADDR_SIZE     (PMD_SIZE + FIX_FDT_SIZE)
101 #else
102 #define MAX_FDT_SIZE	 PGDIR_SIZE
103 #define FIX_FDT_SIZE	 MAX_FDT_SIZE
104 #define FIXADDR_SIZE     (PGDIR_SIZE + FIX_FDT_SIZE)
105 #endif
106 #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
107 
108 #endif
109 
110 #ifdef CONFIG_XIP_KERNEL
111 #define XIP_OFFSET		SZ_32M
112 #define XIP_OFFSET_MASK		(SZ_32M - 1)
113 #else
114 #define XIP_OFFSET		0
115 #endif
116 
117 #ifndef __ASSEMBLY__
118 
119 #include <asm/page.h>
120 #include <asm/tlbflush.h>
121 #include <linux/mm_types.h>
122 #include <asm/compat.h>
123 
124 #define __page_val_to_pfn(_val)  (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT)
125 
126 #ifdef CONFIG_64BIT
127 #include <asm/pgtable-64.h>
128 
129 #define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1))
130 #define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
131 #define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
132 
133 #define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
134 #define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
135 #define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
136 #define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
137 #else
138 #include <asm/pgtable-32.h>
139 #endif /* CONFIG_64BIT */
140 
141 #include <linux/page_table_check.h>
142 
143 #ifdef CONFIG_XIP_KERNEL
144 #define XIP_FIXUP(addr) ({							\
145 	uintptr_t __a = (uintptr_t)(addr);					\
146 	(__a >= CONFIG_XIP_PHYS_ADDR && \
147 	 __a < CONFIG_XIP_PHYS_ADDR + XIP_OFFSET * 2) ?	\
148 		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
149 		__a;								\
150 	})
151 #else
152 #define XIP_FIXUP(addr)		(addr)
153 #endif /* CONFIG_XIP_KERNEL */
154 
155 struct pt_alloc_ops {
156 	pte_t *(*get_pte_virt)(phys_addr_t pa);
157 	phys_addr_t (*alloc_pte)(uintptr_t va);
158 #ifndef __PAGETABLE_PMD_FOLDED
159 	pmd_t *(*get_pmd_virt)(phys_addr_t pa);
160 	phys_addr_t (*alloc_pmd)(uintptr_t va);
161 	pud_t *(*get_pud_virt)(phys_addr_t pa);
162 	phys_addr_t (*alloc_pud)(uintptr_t va);
163 	p4d_t *(*get_p4d_virt)(phys_addr_t pa);
164 	phys_addr_t (*alloc_p4d)(uintptr_t va);
165 #endif
166 };
167 
168 extern struct pt_alloc_ops pt_ops __meminitdata;
169 
170 #ifdef CONFIG_MMU
171 /* Number of PGD entries that a user-mode program can use */
172 #define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
173 
174 /* Page protection bits */
175 #define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
176 
177 #define PAGE_NONE		__pgprot(_PAGE_PROT_NONE | _PAGE_READ)
178 #define PAGE_READ		__pgprot(_PAGE_BASE | _PAGE_READ)
179 #define PAGE_WRITE		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
180 #define PAGE_EXEC		__pgprot(_PAGE_BASE | _PAGE_EXEC)
181 #define PAGE_READ_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
182 #define PAGE_WRITE_EXEC		__pgprot(_PAGE_BASE | _PAGE_READ |	\
183 					 _PAGE_EXEC | _PAGE_WRITE)
184 
185 #define PAGE_COPY		PAGE_READ
186 #define PAGE_COPY_EXEC		PAGE_READ_EXEC
187 #define PAGE_SHARED		PAGE_WRITE
188 #define PAGE_SHARED_EXEC	PAGE_WRITE_EXEC
189 
190 #define _PAGE_KERNEL		(_PAGE_READ \
191 				| _PAGE_WRITE \
192 				| _PAGE_PRESENT \
193 				| _PAGE_ACCESSED \
194 				| _PAGE_DIRTY \
195 				| _PAGE_GLOBAL)
196 
197 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
198 #define PAGE_KERNEL_READ	__pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
199 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL | _PAGE_EXEC)
200 #define PAGE_KERNEL_READ_EXEC	__pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \
201 					 | _PAGE_EXEC)
202 
203 #define PAGE_TABLE		__pgprot(_PAGE_TABLE)
204 
205 #define _PAGE_IOREMAP	((_PAGE_KERNEL & ~_PAGE_MTMASK) | _PAGE_IO)
206 #define PAGE_KERNEL_IO		__pgprot(_PAGE_IOREMAP)
207 
208 extern pgd_t swapper_pg_dir[];
209 extern pgd_t trampoline_pg_dir[];
210 extern pgd_t early_pg_dir[];
211 
212 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
213 static inline int pmd_present(pmd_t pmd)
214 {
215 	/*
216 	 * Checking for _PAGE_LEAF is needed too because:
217 	 * When splitting a THP, split_huge_page() will temporarily clear
218 	 * the present bit, in this situation, pmd_present() and
219 	 * pmd_trans_huge() still needs to return true.
220 	 */
221 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE | _PAGE_LEAF));
222 }
223 #else
224 static inline int pmd_present(pmd_t pmd)
225 {
226 	return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
227 }
228 #endif
229 
230 static inline int pmd_none(pmd_t pmd)
231 {
232 	return (pmd_val(pmd) == 0);
233 }
234 
235 static inline int pmd_bad(pmd_t pmd)
236 {
237 	return !pmd_present(pmd) || (pmd_val(pmd) & _PAGE_LEAF);
238 }
239 
240 #define pmd_leaf	pmd_leaf
241 static inline bool pmd_leaf(pmd_t pmd)
242 {
243 	return pmd_present(pmd) && (pmd_val(pmd) & _PAGE_LEAF);
244 }
245 
246 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
247 {
248 	WRITE_ONCE(*pmdp, pmd);
249 }
250 
251 static inline void pmd_clear(pmd_t *pmdp)
252 {
253 	set_pmd(pmdp, __pmd(0));
254 }
255 
256 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
257 {
258 	unsigned long prot_val = pgprot_val(prot);
259 
260 	ALT_THEAD_PMA(prot_val);
261 
262 	return __pgd((pfn << _PAGE_PFN_SHIFT) | prot_val);
263 }
264 
265 static inline unsigned long _pgd_pfn(pgd_t pgd)
266 {
267 	return __page_val_to_pfn(pgd_val(pgd));
268 }
269 
270 static inline struct page *pmd_page(pmd_t pmd)
271 {
272 	return pfn_to_page(__page_val_to_pfn(pmd_val(pmd)));
273 }
274 
275 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
276 {
277 	return (unsigned long)pfn_to_virt(__page_val_to_pfn(pmd_val(pmd)));
278 }
279 
280 static inline pte_t pmd_pte(pmd_t pmd)
281 {
282 	return __pte(pmd_val(pmd));
283 }
284 
285 static inline pte_t pud_pte(pud_t pud)
286 {
287 	return __pte(pud_val(pud));
288 }
289 
290 #ifdef CONFIG_RISCV_ISA_SVNAPOT
291 #include <asm/cpufeature.h>
292 
293 static __always_inline bool has_svnapot(void)
294 {
295 	return riscv_has_extension_likely(RISCV_ISA_EXT_SVNAPOT);
296 }
297 
298 static inline unsigned long pte_napot(pte_t pte)
299 {
300 	return pte_val(pte) & _PAGE_NAPOT;
301 }
302 
303 static inline pte_t pte_mknapot(pte_t pte, unsigned int order)
304 {
305 	int pos = order - 1 + _PAGE_PFN_SHIFT;
306 	unsigned long napot_bit = BIT(pos);
307 	unsigned long napot_mask = ~GENMASK(pos, _PAGE_PFN_SHIFT);
308 
309 	return __pte((pte_val(pte) & napot_mask) | napot_bit | _PAGE_NAPOT);
310 }
311 
312 #else
313 
314 static __always_inline bool has_svnapot(void) { return false; }
315 
316 static inline unsigned long pte_napot(pte_t pte)
317 {
318 	return 0;
319 }
320 
321 #endif /* CONFIG_RISCV_ISA_SVNAPOT */
322 
323 /* Yields the page frame number (PFN) of a page table entry */
324 static inline unsigned long pte_pfn(pte_t pte)
325 {
326 	unsigned long res  = __page_val_to_pfn(pte_val(pte));
327 
328 	if (has_svnapot() && pte_napot(pte))
329 		res = res & (res - 1UL);
330 
331 	return res;
332 }
333 
334 #define pte_page(x)     pfn_to_page(pte_pfn(x))
335 
336 /* Constructs a page table entry */
337 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
338 {
339 	unsigned long prot_val = pgprot_val(prot);
340 
341 	ALT_THEAD_PMA(prot_val);
342 
343 	return __pte((pfn << _PAGE_PFN_SHIFT) | prot_val);
344 }
345 
346 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
347 
348 static inline int pte_present(pte_t pte)
349 {
350 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
351 }
352 
353 #define pte_accessible pte_accessible
354 static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
355 {
356 	if (pte_val(a) & _PAGE_PRESENT)
357 		return true;
358 
359 	if ((pte_val(a) & _PAGE_PROT_NONE) &&
360 	    atomic_read(&mm->tlb_flush_pending))
361 		return true;
362 
363 	return false;
364 }
365 
366 static inline int pte_none(pte_t pte)
367 {
368 	return (pte_val(pte) == 0);
369 }
370 
371 static inline int pte_write(pte_t pte)
372 {
373 	return pte_val(pte) & _PAGE_WRITE;
374 }
375 
376 static inline int pte_exec(pte_t pte)
377 {
378 	return pte_val(pte) & _PAGE_EXEC;
379 }
380 
381 static inline int pte_user(pte_t pte)
382 {
383 	return pte_val(pte) & _PAGE_USER;
384 }
385 
386 static inline int pte_huge(pte_t pte)
387 {
388 	return pte_present(pte) && (pte_val(pte) & _PAGE_LEAF);
389 }
390 
391 static inline int pte_dirty(pte_t pte)
392 {
393 	return pte_val(pte) & _PAGE_DIRTY;
394 }
395 
396 static inline int pte_young(pte_t pte)
397 {
398 	return pte_val(pte) & _PAGE_ACCESSED;
399 }
400 
401 static inline int pte_special(pte_t pte)
402 {
403 	return pte_val(pte) & _PAGE_SPECIAL;
404 }
405 
406 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
407 static inline int pte_devmap(pte_t pte)
408 {
409 	return pte_val(pte) & _PAGE_DEVMAP;
410 }
411 #endif
412 
413 /* static inline pte_t pte_rdprotect(pte_t pte) */
414 
415 static inline pte_t pte_wrprotect(pte_t pte)
416 {
417 	return __pte(pte_val(pte) & ~(_PAGE_WRITE));
418 }
419 
420 /* static inline pte_t pte_mkread(pte_t pte) */
421 
422 static inline pte_t pte_mkwrite_novma(pte_t pte)
423 {
424 	return __pte(pte_val(pte) | _PAGE_WRITE);
425 }
426 
427 /* static inline pte_t pte_mkexec(pte_t pte) */
428 
429 static inline pte_t pte_mkdirty(pte_t pte)
430 {
431 	return __pte(pte_val(pte) | _PAGE_DIRTY);
432 }
433 
434 static inline pte_t pte_mkclean(pte_t pte)
435 {
436 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
437 }
438 
439 static inline pte_t pte_mkyoung(pte_t pte)
440 {
441 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
442 }
443 
444 static inline pte_t pte_mkold(pte_t pte)
445 {
446 	return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
447 }
448 
449 static inline pte_t pte_mkspecial(pte_t pte)
450 {
451 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
452 }
453 
454 static inline pte_t pte_mkdevmap(pte_t pte)
455 {
456 	return __pte(pte_val(pte) | _PAGE_DEVMAP);
457 }
458 
459 static inline pte_t pte_mkhuge(pte_t pte)
460 {
461 	return pte;
462 }
463 
464 #ifdef CONFIG_RISCV_ISA_SVNAPOT
465 #define pte_leaf_size(pte)	(pte_napot(pte) ?				\
466 					napot_cont_size(napot_cont_order(pte)) :\
467 					PAGE_SIZE)
468 #endif
469 
470 #ifdef CONFIG_NUMA_BALANCING
471 /*
472  * See the comment in include/asm-generic/pgtable.h
473  */
474 static inline int pte_protnone(pte_t pte)
475 {
476 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
477 }
478 
479 static inline int pmd_protnone(pmd_t pmd)
480 {
481 	return pte_protnone(pmd_pte(pmd));
482 }
483 #endif
484 
485 /* Modify page protection bits */
486 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
487 {
488 	unsigned long newprot_val = pgprot_val(newprot);
489 
490 	ALT_THEAD_PMA(newprot_val);
491 
492 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | newprot_val);
493 }
494 
495 #define pgd_ERROR(e) \
496 	pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
497 
498 
499 /* Commit new configuration to MMU hardware */
500 static inline void update_mmu_cache_range(struct vm_fault *vmf,
501 		struct vm_area_struct *vma, unsigned long address,
502 		pte_t *ptep, unsigned int nr)
503 {
504 	/*
505 	 * The kernel assumes that TLBs don't cache invalid entries, but
506 	 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
507 	 * cache flush; it is necessary even after writing invalid entries.
508 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
509 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
510 	 */
511 	while (nr--)
512 		local_flush_tlb_page(address + nr * PAGE_SIZE);
513 }
514 #define update_mmu_cache(vma, addr, ptep) \
515 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
516 
517 #define update_mmu_tlb_range(vma, addr, ptep, nr) \
518 	update_mmu_cache_range(NULL, vma, addr, ptep, nr)
519 
520 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
521 		unsigned long address, pmd_t *pmdp)
522 {
523 	pte_t *ptep = (pte_t *)pmdp;
524 
525 	update_mmu_cache(vma, address, ptep);
526 }
527 
528 #define __HAVE_ARCH_PTE_SAME
529 static inline int pte_same(pte_t pte_a, pte_t pte_b)
530 {
531 	return pte_val(pte_a) == pte_val(pte_b);
532 }
533 
534 /*
535  * Certain architectures need to do special things when PTEs within
536  * a page table are directly modified.  Thus, the following hook is
537  * made available.
538  */
539 static inline void set_pte(pte_t *ptep, pte_t pteval)
540 {
541 	WRITE_ONCE(*ptep, pteval);
542 }
543 
544 void flush_icache_pte(struct mm_struct *mm, pte_t pte);
545 
546 static inline void __set_pte_at(struct mm_struct *mm, pte_t *ptep, pte_t pteval)
547 {
548 	if (pte_present(pteval) && pte_exec(pteval))
549 		flush_icache_pte(mm, pteval);
550 
551 	set_pte(ptep, pteval);
552 }
553 
554 #define PFN_PTE_SHIFT		_PAGE_PFN_SHIFT
555 
556 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
557 		pte_t *ptep, pte_t pteval, unsigned int nr)
558 {
559 	page_table_check_ptes_set(mm, ptep, pteval, nr);
560 
561 	for (;;) {
562 		__set_pte_at(mm, ptep, pteval);
563 		if (--nr == 0)
564 			break;
565 		ptep++;
566 		pte_val(pteval) += 1 << _PAGE_PFN_SHIFT;
567 	}
568 }
569 #define set_ptes set_ptes
570 
571 static inline void pte_clear(struct mm_struct *mm,
572 	unsigned long addr, pte_t *ptep)
573 {
574 	__set_pte_at(mm, ptep, __pte(0));
575 }
576 
577 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS	/* defined in mm/pgtable.c */
578 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
579 				 pte_t *ptep, pte_t entry, int dirty);
580 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG	/* defined in mm/pgtable.c */
581 extern int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long address,
582 				     pte_t *ptep);
583 
584 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
585 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
586 				       unsigned long address, pte_t *ptep)
587 {
588 	pte_t pte = __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
589 
590 	page_table_check_pte_clear(mm, pte);
591 
592 	return pte;
593 }
594 
595 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
596 static inline void ptep_set_wrprotect(struct mm_struct *mm,
597 				      unsigned long address, pte_t *ptep)
598 {
599 	atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
600 }
601 
602 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
603 static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
604 					 unsigned long address, pte_t *ptep)
605 {
606 	/*
607 	 * This comment is borrowed from x86, but applies equally to RISC-V:
608 	 *
609 	 * Clearing the accessed bit without a TLB flush
610 	 * doesn't cause data corruption. [ It could cause incorrect
611 	 * page aging and the (mistaken) reclaim of hot pages, but the
612 	 * chance of that should be relatively low. ]
613 	 *
614 	 * So as a performance optimization don't flush the TLB when
615 	 * clearing the accessed bit, it will eventually be flushed by
616 	 * a context switch or a VM operation anyway. [ In the rare
617 	 * event of it not getting flushed for a long time the delay
618 	 * shouldn't really matter because there's no real memory
619 	 * pressure for swapout to react to. ]
620 	 */
621 	return ptep_test_and_clear_young(vma, address, ptep);
622 }
623 
624 #define pgprot_nx pgprot_nx
625 static inline pgprot_t pgprot_nx(pgprot_t _prot)
626 {
627 	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
628 }
629 
630 #define pgprot_noncached pgprot_noncached
631 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
632 {
633 	unsigned long prot = pgprot_val(_prot);
634 
635 	prot &= ~_PAGE_MTMASK;
636 	prot |= _PAGE_IO;
637 
638 	return __pgprot(prot);
639 }
640 
641 #define pgprot_writecombine pgprot_writecombine
642 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
643 {
644 	unsigned long prot = pgprot_val(_prot);
645 
646 	prot &= ~_PAGE_MTMASK;
647 	prot |= _PAGE_NOCACHE;
648 
649 	return __pgprot(prot);
650 }
651 
652 /*
653  * THP functions
654  */
655 static inline pmd_t pte_pmd(pte_t pte)
656 {
657 	return __pmd(pte_val(pte));
658 }
659 
660 static inline pmd_t pmd_mkhuge(pmd_t pmd)
661 {
662 	return pmd;
663 }
664 
665 static inline pmd_t pmd_mkinvalid(pmd_t pmd)
666 {
667 	return __pmd(pmd_val(pmd) & ~(_PAGE_PRESENT|_PAGE_PROT_NONE));
668 }
669 
670 #define __pmd_to_phys(pmd)  (__page_val_to_pfn(pmd_val(pmd)) << PAGE_SHIFT)
671 
672 static inline unsigned long pmd_pfn(pmd_t pmd)
673 {
674 	return ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT);
675 }
676 
677 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
678 
679 #define pud_pfn pud_pfn
680 static inline unsigned long pud_pfn(pud_t pud)
681 {
682 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
683 }
684 
685 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
686 {
687 	return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
688 }
689 
690 #define pmd_write pmd_write
691 static inline int pmd_write(pmd_t pmd)
692 {
693 	return pte_write(pmd_pte(pmd));
694 }
695 
696 #define pud_write pud_write
697 static inline int pud_write(pud_t pud)
698 {
699 	return pte_write(pud_pte(pud));
700 }
701 
702 #define pmd_dirty pmd_dirty
703 static inline int pmd_dirty(pmd_t pmd)
704 {
705 	return pte_dirty(pmd_pte(pmd));
706 }
707 
708 #define pmd_young pmd_young
709 static inline int pmd_young(pmd_t pmd)
710 {
711 	return pte_young(pmd_pte(pmd));
712 }
713 
714 static inline int pmd_user(pmd_t pmd)
715 {
716 	return pte_user(pmd_pte(pmd));
717 }
718 
719 static inline pmd_t pmd_mkold(pmd_t pmd)
720 {
721 	return pte_pmd(pte_mkold(pmd_pte(pmd)));
722 }
723 
724 static inline pmd_t pmd_mkyoung(pmd_t pmd)
725 {
726 	return pte_pmd(pte_mkyoung(pmd_pte(pmd)));
727 }
728 
729 static inline pmd_t pmd_mkwrite_novma(pmd_t pmd)
730 {
731 	return pte_pmd(pte_mkwrite_novma(pmd_pte(pmd)));
732 }
733 
734 static inline pmd_t pmd_wrprotect(pmd_t pmd)
735 {
736 	return pte_pmd(pte_wrprotect(pmd_pte(pmd)));
737 }
738 
739 static inline pmd_t pmd_mkclean(pmd_t pmd)
740 {
741 	return pte_pmd(pte_mkclean(pmd_pte(pmd)));
742 }
743 
744 static inline pmd_t pmd_mkdirty(pmd_t pmd)
745 {
746 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
747 }
748 
749 static inline pmd_t pmd_mkdevmap(pmd_t pmd)
750 {
751 	return pte_pmd(pte_mkdevmap(pmd_pte(pmd)));
752 }
753 
754 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
755 				pmd_t *pmdp, pmd_t pmd)
756 {
757 	page_table_check_pmd_set(mm, pmdp, pmd);
758 	return __set_pte_at(mm, (pte_t *)pmdp, pmd_pte(pmd));
759 }
760 
761 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
762 				pud_t *pudp, pud_t pud)
763 {
764 	page_table_check_pud_set(mm, pudp, pud);
765 	return __set_pte_at(mm, (pte_t *)pudp, pud_pte(pud));
766 }
767 
768 #ifdef CONFIG_PAGE_TABLE_CHECK
769 static inline bool pte_user_accessible_page(pte_t pte)
770 {
771 	return pte_present(pte) && pte_user(pte);
772 }
773 
774 static inline bool pmd_user_accessible_page(pmd_t pmd)
775 {
776 	return pmd_leaf(pmd) && pmd_user(pmd);
777 }
778 
779 static inline bool pud_user_accessible_page(pud_t pud)
780 {
781 	return pud_leaf(pud) && pud_user(pud);
782 }
783 #endif
784 
785 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
786 static inline int pmd_trans_huge(pmd_t pmd)
787 {
788 	return pmd_leaf(pmd);
789 }
790 
791 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
792 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
793 					unsigned long address, pmd_t *pmdp,
794 					pmd_t entry, int dirty)
795 {
796 	return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
797 }
798 
799 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
800 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
801 					unsigned long address, pmd_t *pmdp)
802 {
803 	return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
804 }
805 
806 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
807 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
808 					unsigned long address, pmd_t *pmdp)
809 {
810 	pmd_t pmd = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0));
811 
812 	page_table_check_pmd_clear(mm, pmd);
813 
814 	return pmd;
815 }
816 
817 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
818 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
819 					unsigned long address, pmd_t *pmdp)
820 {
821 	ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
822 }
823 
824 #define pmdp_establish pmdp_establish
825 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
826 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
827 {
828 	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
829 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
830 }
831 
832 #define pmdp_collapse_flush pmdp_collapse_flush
833 extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
834 				 unsigned long address, pmd_t *pmdp);
835 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
836 
837 /*
838  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
839  * are !pte_none() && !pte_present().
840  *
841  * Format of swap PTE:
842  *	bit            0:	_PAGE_PRESENT (zero)
843  *	bit       1 to 3:       _PAGE_LEAF (zero)
844  *	bit            5:	_PAGE_PROT_NONE (zero)
845  *	bit            6:	exclusive marker
846  *	bits      7 to 11:	swap type
847  *	bits 12 to XLEN-1:	swap offset
848  */
849 #define __SWP_TYPE_SHIFT	7
850 #define __SWP_TYPE_BITS		5
851 #define __SWP_TYPE_MASK		((1UL << __SWP_TYPE_BITS) - 1)
852 #define __SWP_OFFSET_SHIFT	(__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
853 
854 #define MAX_SWAPFILES_CHECK()	\
855 	BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
856 
857 #define __swp_type(x)	(((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
858 #define __swp_offset(x)	((x).val >> __SWP_OFFSET_SHIFT)
859 #define __swp_entry(type, offset) ((swp_entry_t) \
860 	{ (((type) & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT) | \
861 	  ((offset) << __SWP_OFFSET_SHIFT) })
862 
863 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
864 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
865 
866 static inline int pte_swp_exclusive(pte_t pte)
867 {
868 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
869 }
870 
871 static inline pte_t pte_swp_mkexclusive(pte_t pte)
872 {
873 	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
874 }
875 
876 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
877 {
878 	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
879 }
880 
881 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
882 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
883 #define __swp_entry_to_pmd(swp) __pmd((swp).val)
884 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
885 
886 /*
887  * In the RV64 Linux scheme, we give the user half of the virtual-address space
888  * and give the kernel the other (upper) half.
889  */
890 #ifdef CONFIG_64BIT
891 #define KERN_VIRT_START	(-(BIT(VA_BITS)) + TASK_SIZE)
892 #else
893 #define KERN_VIRT_START	FIXADDR_START
894 #endif
895 
896 /*
897  * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
898  * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
899  * Task size is:
900  * -        0x9fc00000	(~2.5GB) for RV32.
901  * -      0x4000000000	( 256GB) for RV64 using SV39 mmu
902  * -    0x800000000000	( 128TB) for RV64 using SV48 mmu
903  * - 0x100000000000000	(  64PB) for RV64 using SV57 mmu
904  *
905  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
906  * Instruction Set Manual Volume II: Privileged Architecture" states that
907  * "load and store effective addresses, which are 64bits, must have bits
908  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
909  * Similarly for SV57, bits 63–57 must be equal to bit 56.
910  */
911 #ifdef CONFIG_64BIT
912 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
913 #define TASK_SIZE_MAX	LONG_MAX
914 
915 #ifdef CONFIG_COMPAT
916 #define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
917 #define TASK_SIZE	(is_compat_task() ? \
918 			 TASK_SIZE_32 : TASK_SIZE_64)
919 #else
920 #define TASK_SIZE	TASK_SIZE_64
921 #endif
922 
923 #else
924 #define TASK_SIZE	FIXADDR_START
925 #endif
926 
927 #else /* CONFIG_MMU */
928 
929 #define PAGE_SHARED		__pgprot(0)
930 #define PAGE_KERNEL		__pgprot(0)
931 #define swapper_pg_dir		NULL
932 #define TASK_SIZE		_AC(-1, UL)
933 #define VMALLOC_START		_AC(0, UL)
934 #define VMALLOC_END		TASK_SIZE
935 
936 #endif /* !CONFIG_MMU */
937 
938 extern char _start[];
939 extern void *_dtb_early_va;
940 extern uintptr_t _dtb_early_pa;
941 #if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_MMU)
942 #define dtb_early_va	(*(void **)XIP_FIXUP(&_dtb_early_va))
943 #define dtb_early_pa	(*(uintptr_t *)XIP_FIXUP(&_dtb_early_pa))
944 #else
945 #define dtb_early_va	_dtb_early_va
946 #define dtb_early_pa	_dtb_early_pa
947 #endif /* CONFIG_XIP_KERNEL */
948 extern u64 satp_mode;
949 
950 void paging_init(void);
951 void misc_mem_init(void);
952 
953 /*
954  * ZERO_PAGE is a global shared page that is always zero,
955  * used for zero-mapped memory areas, etc.
956  */
957 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
958 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
959 
960 #endif /* !__ASSEMBLY__ */
961 
962 #endif /* _ASM_RISCV_PGTABLE_H */
963