1// SPDX-License-Identifier: GPL-2.0
2#include <linux/hugetlb.h>
3#include <linux/err.h>
4
5#ifdef CONFIG_RISCV_ISA_SVNAPOT
6pte_t huge_ptep_get(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
30pte_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
75out:
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
84pte_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
128unsigned 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
148static 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
169static 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
184pte_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
200static 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 */
223void 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
263int 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
294pte_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
309void 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
334pte_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
349void 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
367static 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
381static __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}
391arch_initcall(napot_hugetlbpages_init);
392
393#else
394
395static bool is_napot_size(unsigned long size)
396{
397	return false;
398}
399
400#endif /*CONFIG_RISCV_ISA_SVNAPOT*/
401
402int pud_huge(pud_t pud)
403{
404	return pud_leaf(pud);
405}
406
407int pmd_huge(pmd_t pmd)
408{
409	return pmd_leaf(pmd);
410}
411
412static bool __hugetlb_valid_size(unsigned long size)
413{
414	if (size == HPAGE_SIZE)
415		return true;
416	else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
417		return true;
418	else if (is_napot_size(size))
419		return true;
420	else
421		return false;
422}
423
424bool __init arch_hugetlb_valid_size(unsigned long size)
425{
426	return __hugetlb_valid_size(size);
427}
428
429#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
430bool arch_hugetlb_migration_supported(struct hstate *h)
431{
432	return __hugetlb_valid_size(huge_page_size(h));
433}
434#endif
435
436#ifdef CONFIG_CONTIG_ALLOC
437static __init int gigantic_pages_init(void)
438{
439	/* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
440	if (IS_ENABLED(CONFIG_64BIT))
441		hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
442	return 0;
443}
444arch_initcall(gigantic_pages_init);
445#endif
446