1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/hugetlb.h>
3 #include <linux/err.h>
4
5 #ifdef CONFIG_RISCV_ISA_SVNAPOT
6 pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
7 {
8 unsigned long pte_num;
9 int i;
10 pte_t orig_pte = ptep_get(ptep);
11
12 if (!pte_present(orig_pte) || !pte_napot(orig_pte))
13 return orig_pte;
14
15 pte_num = napot_pte_num(napot_cont_order(orig_pte));
16
17 for (i = 0; i < pte_num; i++, ptep++) {
18 pte_t pte = ptep_get(ptep);
19
20 if (pte_dirty(pte))
21 orig_pte = pte_mkdirty(orig_pte);
22
23 if (pte_young(pte))
24 orig_pte = pte_mkyoung(orig_pte);
25 }
26
27 return orig_pte;
28 }
29
30 pte_t *huge_pte_alloc(struct mm_struct *mm,
31 struct vm_area_struct *vma,
32 unsigned long addr,
33 unsigned long sz)
34 {
35 unsigned long order;
36 pte_t *pte = NULL;
37 pgd_t *pgd;
38 p4d_t *p4d;
39 pud_t *pud;
40 pmd_t *pmd;
41
42 pgd = pgd_offset(mm, addr);
43 p4d = p4d_alloc(mm, pgd, addr);
44 if (!p4d)
45 return NULL;
46
47 pud = pud_alloc(mm, p4d, addr);
48 if (!pud)
49 return NULL;
50
51 if (sz == PUD_SIZE) {
52 pte = (pte_t *)pud;
53 goto out;
54 }
55
56 if (sz == PMD_SIZE) {
57 if (want_pmd_share(vma, addr) && pud_none(pudp_get(pud)))
58 pte = huge_pmd_share(mm, vma, addr, pud);
59 else
60 pte = (pte_t *)pmd_alloc(mm, pud, addr);
61 goto out;
62 }
63
64 pmd = pmd_alloc(mm, pud, addr);
65 if (!pmd)
66 return NULL;
67
68 for_each_napot_order(order) {
69 if (napot_cont_size(order) == sz) {
70 pte = pte_alloc_huge(mm, pmd, addr & napot_cont_mask(order));
71 break;
72 }
73 }
74
75 out:
76 if (pte) {
77 pte_t pteval = ptep_get_lockless(pte);
78
79 WARN_ON_ONCE(pte_present(pteval) && !pte_huge(pteval));
80 }
81 return pte;
82 }
83
84 pte_t *huge_pte_offset(struct mm_struct *mm,
85 unsigned long addr,
86 unsigned long sz)
87 {
88 unsigned long order;
89 pte_t *pte = NULL;
90 pgd_t *pgd;
91 p4d_t *p4d;
92 pud_t *pud;
93 pmd_t *pmd;
94
95 pgd = pgd_offset(mm, addr);
96 if (!pgd_present(pgdp_get(pgd)))
97 return NULL;
98
99 p4d = p4d_offset(pgd, addr);
100 if (!p4d_present(p4dp_get(p4d)))
101 return NULL;
102
103 pud = pud_offset(p4d, addr);
104 if (sz == PUD_SIZE)
105 /* must be pud huge, non-present or none */
106 return (pte_t *)pud;
107
108 if (!pud_present(pudp_get(pud)))
109 return NULL;
110
111 pmd = pmd_offset(pud, addr);
112 if (sz == PMD_SIZE)
113 /* must be pmd huge, non-present or none */
114 return (pte_t *)pmd;
115
116 if (!pmd_present(pmdp_get(pmd)))
117 return NULL;
118
119 for_each_napot_order(order) {
120 if (napot_cont_size(order) == sz) {
121 pte = pte_offset_huge(pmd, addr & napot_cont_mask(order));
122 break;
123 }
124 }
125 return pte;
126 }
127
128 unsigned long hugetlb_mask_last_page(struct hstate *h)
129 {
130 unsigned long hp_size = huge_page_size(h);
131
132 switch (hp_size) {
133 #ifndef __PAGETABLE_PMD_FOLDED
134 case PUD_SIZE:
135 return P4D_SIZE - PUD_SIZE;
136 #endif
137 case PMD_SIZE:
138 return PUD_SIZE - PMD_SIZE;
139 case napot_cont_size(NAPOT_CONT64KB_ORDER):
140 return PMD_SIZE - napot_cont_size(NAPOT_CONT64KB_ORDER);
141 default:
142 break;
143 }
144
145 return 0UL;
146 }
147
148 static pte_t get_clear_contig(struct mm_struct *mm,
149 unsigned long addr,
150 pte_t *ptep,
151 unsigned long pte_num)
152 {
153 pte_t orig_pte = ptep_get(ptep);
154 unsigned long i;
155
156 for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {
157 pte_t pte = ptep_get_and_clear(mm, addr, ptep);
158
159 if (pte_dirty(pte))
160 orig_pte = pte_mkdirty(orig_pte);
161
162 if (pte_young(pte))
163 orig_pte = pte_mkyoung(orig_pte);
164 }
165
166 return orig_pte;
167 }
168
169 static pte_t get_clear_contig_flush(struct mm_struct *mm,
170 unsigned long addr,
171 pte_t *ptep,
172 unsigned long pte_num)
173 {
174 pte_t orig_pte = get_clear_contig(mm, addr, ptep, pte_num);
175 struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
176 bool valid = !pte_none(orig_pte);
177
178 if (valid)
179 flush_tlb_range(&vma, addr, addr + (PAGE_SIZE * pte_num));
180
181 return orig_pte;
182 }
183
184 pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
185 {
186 unsigned long order;
187
188 for_each_napot_order(order) {
189 if (shift == napot_cont_shift(order)) {
190 entry = pte_mknapot(entry, order);
191 break;
192 }
193 }
194 if (order == NAPOT_ORDER_MAX)
195 entry = pte_mkhuge(entry);
196
197 return entry;
198 }
199
200 static void clear_flush(struct mm_struct *mm,
201 unsigned long addr,
202 pte_t *ptep,
203 unsigned long pgsize,
204 unsigned long ncontig)
205 {
206 struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
207 unsigned long i, saddr = addr;
208
209 for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
210 ptep_get_and_clear(mm, addr, ptep);
211
212 flush_tlb_range(&vma, saddr, addr);
213 }
214
215 /*
216 * When dealing with NAPOT mappings, the privileged specification indicates that
217 * "if an update needs to be made, the OS generally should first mark all of the
218 * PTEs invalid, then issue SFENCE.VMA instruction(s) covering all 4 KiB regions
219 * within the range, [...] then update the PTE(s), as described in Section
220 * 4.2.1.". That's the equivalent of the Break-Before-Make approach used by
221 * arm64.
222 */
223 void set_huge_pte_at(struct mm_struct *mm,
224 unsigned long addr,
225 pte_t *ptep,
226 pte_t pte,
227 unsigned long sz)
228 {
229 unsigned long hugepage_shift, pgsize;
230 int i, pte_num;
231
232 if (sz >= PGDIR_SIZE)
233 hugepage_shift = PGDIR_SHIFT;
234 else if (sz >= P4D_SIZE)
235 hugepage_shift = P4D_SHIFT;
236 else if (sz >= PUD_SIZE)
237 hugepage_shift = PUD_SHIFT;
238 else if (sz >= PMD_SIZE)
239 hugepage_shift = PMD_SHIFT;
240 else
241 hugepage_shift = PAGE_SHIFT;
242
243 pte_num = sz >> hugepage_shift;
244 pgsize = 1 << hugepage_shift;
245
246 if (!pte_present(pte)) {
247 for (i = 0; i < pte_num; i++, ptep++, addr += pgsize)
248 set_ptes(mm, addr, ptep, pte, 1);
249 return;
250 }
251
252 if (!pte_napot(pte)) {
253 set_ptes(mm, addr, ptep, pte, 1);
254 return;
255 }
256
257 clear_flush(mm, addr, ptep, pgsize, pte_num);
258
259 for (i = 0; i < pte_num; i++, ptep++, addr += pgsize)
260 set_pte_at(mm, addr, ptep, pte);
261 }
262
263 int huge_ptep_set_access_flags(struct vm_area_struct *vma,
264 unsigned long addr,
265 pte_t *ptep,
266 pte_t pte,
267 int dirty)
268 {
269 struct mm_struct *mm = vma->vm_mm;
270 unsigned long order;
271 pte_t orig_pte;
272 int i, pte_num;
273
274 if (!pte_napot(pte))
275 return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
276
277 order = napot_cont_order(pte);
278 pte_num = napot_pte_num(order);
279 ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
280 orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
281
282 if (pte_dirty(orig_pte))
283 pte = pte_mkdirty(pte);
284
285 if (pte_young(orig_pte))
286 pte = pte_mkyoung(pte);
287
288 for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
289 set_pte_at(mm, addr, ptep, pte);
290
291 return true;
292 }
293
294 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
295 unsigned long addr,
296 pte_t *ptep)
297 {
298 pte_t orig_pte = ptep_get(ptep);
299 int pte_num;
300
301 if (!pte_napot(orig_pte))
302 return ptep_get_and_clear(mm, addr, ptep);
303
304 pte_num = napot_pte_num(napot_cont_order(orig_pte));
305
306 return get_clear_contig(mm, addr, ptep, pte_num);
307 }
308
309 void huge_ptep_set_wrprotect(struct mm_struct *mm,
310 unsigned long addr,
311 pte_t *ptep)
312 {
313 pte_t pte = ptep_get(ptep);
314 unsigned long order;
315 pte_t orig_pte;
316 int i, pte_num;
317
318 if (!pte_napot(pte)) {
319 ptep_set_wrprotect(mm, addr, ptep);
320 return;
321 }
322
323 order = napot_cont_order(pte);
324 pte_num = napot_pte_num(order);
325 ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
326 orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
327
328 orig_pte = pte_wrprotect(orig_pte);
329
330 for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
331 set_pte_at(mm, addr, ptep, orig_pte);
332 }
333
334 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
335 unsigned long addr,
336 pte_t *ptep)
337 {
338 pte_t pte = ptep_get(ptep);
339 int pte_num;
340
341 if (!pte_napot(pte))
342 return ptep_clear_flush(vma, addr, ptep);
343
344 pte_num = napot_pte_num(napot_cont_order(pte));
345
346 return get_clear_contig_flush(vma->vm_mm, addr, ptep, pte_num);
347 }
348
349 void huge_pte_clear(struct mm_struct *mm,
350 unsigned long addr,
351 pte_t *ptep,
352 unsigned long sz)
353 {
354 pte_t pte = ptep_get(ptep);
355 int i, pte_num;
356
357 if (!pte_napot(pte)) {
358 pte_clear(mm, addr, ptep);
359 return;
360 }
361
362 pte_num = napot_pte_num(napot_cont_order(pte));
363 for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
364 pte_clear(mm, addr, ptep);
365 }
366
367 static bool is_napot_size(unsigned long size)
368 {
369 unsigned long order;
370
371 if (!has_svnapot())
372 return false;
373
374 for_each_napot_order(order) {
375 if (size == napot_cont_size(order))
376 return true;
377 }
378 return false;
379 }
380
381 static __init int napot_hugetlbpages_init(void)
382 {
383 if (has_svnapot()) {
384 unsigned long order;
385
386 for_each_napot_order(order)
387 hugetlb_add_hstate(order);
388 }
389 return 0;
390 }
391 arch_initcall(napot_hugetlbpages_init);
392
393 #else
394
395 static bool is_napot_size(unsigned long size)
396 {
397 return false;
398 }
399
400 #endif /*CONFIG_RISCV_ISA_SVNAPOT*/
401
402 static bool __hugetlb_valid_size(unsigned long size)
403 {
404 if (size == HPAGE_SIZE)
405 return true;
406 else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
407 return true;
408 else if (is_napot_size(size))
409 return true;
410 else
411 return false;
412 }
413
414 bool __init arch_hugetlb_valid_size(unsigned long size)
415 {
416 return __hugetlb_valid_size(size);
417 }
418
419 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
420 bool arch_hugetlb_migration_supported(struct hstate *h)
421 {
422 return __hugetlb_valid_size(huge_page_size(h));
423 }
424 #endif
425
426 #ifdef CONFIG_CONTIG_ALLOC
427 static __init int gigantic_pages_init(void)
428 {
429 /* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
430 if (IS_ENABLED(CONFIG_64BIT))
431 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
432 return 0;
433 }
434 arch_initcall(gigantic_pages_init);
435 #endif
436
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