1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SPARC64 Huge TLB page support.
4 *
5 * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
6 */
7
8#include <linux/fs.h>
9#include <linux/mm.h>
10#include <linux/sched/mm.h>
11#include <linux/hugetlb.h>
12#include <linux/pagemap.h>
13#include <linux/sysctl.h>
14
15#include <asm/mman.h>
16#include <asm/pgalloc.h>
17#include <asm/tlb.h>
18#include <asm/tlbflush.h>
19#include <asm/cacheflush.h>
20#include <asm/mmu_context.h>
21
22/* Slightly simplified from the non-hugepage variant because by
23 * definition we don't have to worry about any page coloring stuff
24 */
25
26static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
27							unsigned long addr,
28							unsigned long len,
29							unsigned long pgoff,
30							unsigned long flags)
31{
32	struct hstate *h = hstate_file(filp);
33	unsigned long task_size = TASK_SIZE;
34	struct vm_unmapped_area_info info;
35
36	if (test_thread_flag(TIF_32BIT))
37		task_size = STACK_TOP32;
38
39	info.flags = 0;
40	info.length = len;
41	info.low_limit = TASK_UNMAPPED_BASE;
42	info.high_limit = min(task_size, VA_EXCLUDE_START);
43	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
44	info.align_offset = 0;
45	addr = vm_unmapped_area(&info);
46
47	if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
48		VM_BUG_ON(addr != -ENOMEM);
49		info.low_limit = VA_EXCLUDE_END;
50		info.high_limit = task_size;
51		addr = vm_unmapped_area(&info);
52	}
53
54	return addr;
55}
56
57static unsigned long
58hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
59				  const unsigned long len,
60				  const unsigned long pgoff,
61				  const unsigned long flags)
62{
63	struct hstate *h = hstate_file(filp);
64	struct mm_struct *mm = current->mm;
65	unsigned long addr = addr0;
66	struct vm_unmapped_area_info info;
67
68	/* This should only ever run for 32-bit processes.  */
69	BUG_ON(!test_thread_flag(TIF_32BIT));
70
71	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
72	info.length = len;
73	info.low_limit = PAGE_SIZE;
74	info.high_limit = mm->mmap_base;
75	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
76	info.align_offset = 0;
77	addr = vm_unmapped_area(&info);
78
79	/*
80	 * A failed mmap() very likely causes application failure,
81	 * so fall back to the bottom-up function here. This scenario
82	 * can happen with large stack limits and large mmap()
83	 * allocations.
84	 */
85	if (addr & ~PAGE_MASK) {
86		VM_BUG_ON(addr != -ENOMEM);
87		info.flags = 0;
88		info.low_limit = TASK_UNMAPPED_BASE;
89		info.high_limit = STACK_TOP32;
90		addr = vm_unmapped_area(&info);
91	}
92
93	return addr;
94}
95
96unsigned long
97hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
98		unsigned long len, unsigned long pgoff, unsigned long flags)
99{
100	struct hstate *h = hstate_file(file);
101	struct mm_struct *mm = current->mm;
102	struct vm_area_struct *vma;
103	unsigned long task_size = TASK_SIZE;
104
105	if (test_thread_flag(TIF_32BIT))
106		task_size = STACK_TOP32;
107
108	if (len & ~huge_page_mask(h))
109		return -EINVAL;
110	if (len > task_size)
111		return -ENOMEM;
112
113	if (flags & MAP_FIXED) {
114		if (prepare_hugepage_range(file, addr, len))
115			return -EINVAL;
116		return addr;
117	}
118
119	if (addr) {
120		addr = ALIGN(addr, huge_page_size(h));
121		vma = find_vma(mm, addr);
122		if (task_size - len >= addr &&
123		    (!vma || addr + len <= vm_start_gap(vma)))
124			return addr;
125	}
126	if (mm->get_unmapped_area == arch_get_unmapped_area)
127		return hugetlb_get_unmapped_area_bottomup(file, addr, len,
128				pgoff, flags);
129	else
130		return hugetlb_get_unmapped_area_topdown(file, addr, len,
131				pgoff, flags);
132}
133
134static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
135{
136	return entry;
137}
138
139static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
140{
141	unsigned long hugepage_size = _PAGE_SZ4MB_4V;
142
143	pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;
144
145	switch (shift) {
146	case HPAGE_16GB_SHIFT:
147		hugepage_size = _PAGE_SZ16GB_4V;
148		pte_val(entry) |= _PAGE_PUD_HUGE;
149		break;
150	case HPAGE_2GB_SHIFT:
151		hugepage_size = _PAGE_SZ2GB_4V;
152		pte_val(entry) |= _PAGE_PMD_HUGE;
153		break;
154	case HPAGE_256MB_SHIFT:
155		hugepage_size = _PAGE_SZ256MB_4V;
156		pte_val(entry) |= _PAGE_PMD_HUGE;
157		break;
158	case HPAGE_SHIFT:
159		pte_val(entry) |= _PAGE_PMD_HUGE;
160		break;
161	case HPAGE_64K_SHIFT:
162		hugepage_size = _PAGE_SZ64K_4V;
163		break;
164	default:
165		WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift);
166	}
167
168	pte_val(entry) = pte_val(entry) | hugepage_size;
169	return entry;
170}
171
172static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift)
173{
174	if (tlb_type == hypervisor)
175		return sun4v_hugepage_shift_to_tte(entry, shift);
176	else
177		return sun4u_hugepage_shift_to_tte(entry, shift);
178}
179
180pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
181			 struct page *page, int writeable)
182{
183	unsigned int shift = huge_page_shift(hstate_vma(vma));
184	pte_t pte;
185
186	pte = hugepage_shift_to_tte(entry, shift);
187
188#ifdef CONFIG_SPARC64
189	/* If this vma has ADI enabled on it, turn on TTE.mcd
190	 */
191	if (vma->vm_flags & VM_SPARC_ADI)
192		return pte_mkmcd(pte);
193	else
194		return pte_mknotmcd(pte);
195#else
196	return pte;
197#endif
198}
199
200static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
201{
202	unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
203	unsigned int shift;
204
205	switch (tte_szbits) {
206	case _PAGE_SZ16GB_4V:
207		shift = HPAGE_16GB_SHIFT;
208		break;
209	case _PAGE_SZ2GB_4V:
210		shift = HPAGE_2GB_SHIFT;
211		break;
212	case _PAGE_SZ256MB_4V:
213		shift = HPAGE_256MB_SHIFT;
214		break;
215	case _PAGE_SZ4MB_4V:
216		shift = REAL_HPAGE_SHIFT;
217		break;
218	case _PAGE_SZ64K_4V:
219		shift = HPAGE_64K_SHIFT;
220		break;
221	default:
222		shift = PAGE_SHIFT;
223		break;
224	}
225	return shift;
226}
227
228static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
229{
230	unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
231	unsigned int shift;
232
233	switch (tte_szbits) {
234	case _PAGE_SZ256MB_4U:
235		shift = HPAGE_256MB_SHIFT;
236		break;
237	case _PAGE_SZ4MB_4U:
238		shift = REAL_HPAGE_SHIFT;
239		break;
240	case _PAGE_SZ64K_4U:
241		shift = HPAGE_64K_SHIFT;
242		break;
243	default:
244		shift = PAGE_SHIFT;
245		break;
246	}
247	return shift;
248}
249
250static unsigned int huge_tte_to_shift(pte_t entry)
251{
252	unsigned long shift;
253
254	if (tlb_type == hypervisor)
255		shift = sun4v_huge_tte_to_shift(entry);
256	else
257		shift = sun4u_huge_tte_to_shift(entry);
258
259	if (shift == PAGE_SHIFT)
260		WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
261			  pte_val(entry));
262
263	return shift;
264}
265
266static unsigned long huge_tte_to_size(pte_t pte)
267{
268	unsigned long size = 1UL << huge_tte_to_shift(pte);
269
270	if (size == REAL_HPAGE_SIZE)
271		size = HPAGE_SIZE;
272	return size;
273}
274
275pte_t *huge_pte_alloc(struct mm_struct *mm,
276			unsigned long addr, unsigned long sz)
277{
278	pgd_t *pgd;
279	p4d_t *p4d;
280	pud_t *pud;
281	pmd_t *pmd;
282
283	pgd = pgd_offset(mm, addr);
284	p4d = p4d_offset(pgd, addr);
285	pud = pud_alloc(mm, p4d, addr);
286	if (!pud)
287		return NULL;
288	if (sz >= PUD_SIZE)
289		return (pte_t *)pud;
290	pmd = pmd_alloc(mm, pud, addr);
291	if (!pmd)
292		return NULL;
293	if (sz >= PMD_SIZE)
294		return (pte_t *)pmd;
295	return pte_alloc_map(mm, pmd, addr);
296}
297
298pte_t *huge_pte_offset(struct mm_struct *mm,
299		       unsigned long addr, unsigned long sz)
300{
301	pgd_t *pgd;
302	p4d_t *p4d;
303	pud_t *pud;
304	pmd_t *pmd;
305
306	pgd = pgd_offset(mm, addr);
307	if (pgd_none(*pgd))
308		return NULL;
309	p4d = p4d_offset(pgd, addr);
310	if (p4d_none(*p4d))
311		return NULL;
312	pud = pud_offset(p4d, addr);
313	if (pud_none(*pud))
314		return NULL;
315	if (is_hugetlb_pud(*pud))
316		return (pte_t *)pud;
317	pmd = pmd_offset(pud, addr);
318	if (pmd_none(*pmd))
319		return NULL;
320	if (is_hugetlb_pmd(*pmd))
321		return (pte_t *)pmd;
322	return pte_offset_map(pmd, addr);
323}
324
325void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
326		     pte_t *ptep, pte_t entry)
327{
328	unsigned int nptes, orig_shift, shift;
329	unsigned long i, size;
330	pte_t orig;
331
332	size = huge_tte_to_size(entry);
333
334	shift = PAGE_SHIFT;
335	if (size >= PUD_SIZE)
336		shift = PUD_SHIFT;
337	else if (size >= PMD_SIZE)
338		shift = PMD_SHIFT;
339	else
340		shift = PAGE_SHIFT;
341
342	nptes = size >> shift;
343
344	if (!pte_present(*ptep) && pte_present(entry))
345		mm->context.hugetlb_pte_count += nptes;
346
347	addr &= ~(size - 1);
348	orig = *ptep;
349	orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
350
351	for (i = 0; i < nptes; i++)
352		ptep[i] = __pte(pte_val(entry) + (i << shift));
353
354	maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
355	/* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
356	if (size == HPAGE_SIZE)
357		maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
358				    orig_shift);
359}
360
361pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
362			      pte_t *ptep)
363{
364	unsigned int i, nptes, orig_shift, shift;
365	unsigned long size;
366	pte_t entry;
367
368	entry = *ptep;
369	size = huge_tte_to_size(entry);
370
371	shift = PAGE_SHIFT;
372	if (size >= PUD_SIZE)
373		shift = PUD_SHIFT;
374	else if (size >= PMD_SIZE)
375		shift = PMD_SHIFT;
376	else
377		shift = PAGE_SHIFT;
378
379	nptes = size >> shift;
380	orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
381
382	if (pte_present(entry))
383		mm->context.hugetlb_pte_count -= nptes;
384
385	addr &= ~(size - 1);
386	for (i = 0; i < nptes; i++)
387		ptep[i] = __pte(0UL);
388
389	maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
390	/* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
391	if (size == HPAGE_SIZE)
392		maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
393				    orig_shift);
394
395	return entry;
396}
397
398int pmd_huge(pmd_t pmd)
399{
400	return !pmd_none(pmd) &&
401		(pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
402}
403
404int pud_huge(pud_t pud)
405{
406	return !pud_none(pud) &&
407		(pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
408}
409
410static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
411			   unsigned long addr)
412{
413	pgtable_t token = pmd_pgtable(*pmd);
414
415	pmd_clear(pmd);
416	pte_free_tlb(tlb, token, addr);
417	mm_dec_nr_ptes(tlb->mm);
418}
419
420static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
421				   unsigned long addr, unsigned long end,
422				   unsigned long floor, unsigned long ceiling)
423{
424	pmd_t *pmd;
425	unsigned long next;
426	unsigned long start;
427
428	start = addr;
429	pmd = pmd_offset(pud, addr);
430	do {
431		next = pmd_addr_end(addr, end);
432		if (pmd_none(*pmd))
433			continue;
434		if (is_hugetlb_pmd(*pmd))
435			pmd_clear(pmd);
436		else
437			hugetlb_free_pte_range(tlb, pmd, addr);
438	} while (pmd++, addr = next, addr != end);
439
440	start &= PUD_MASK;
441	if (start < floor)
442		return;
443	if (ceiling) {
444		ceiling &= PUD_MASK;
445		if (!ceiling)
446			return;
447	}
448	if (end - 1 > ceiling - 1)
449		return;
450
451	pmd = pmd_offset(pud, start);
452	pud_clear(pud);
453	pmd_free_tlb(tlb, pmd, start);
454	mm_dec_nr_pmds(tlb->mm);
455}
456
457static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
458				   unsigned long addr, unsigned long end,
459				   unsigned long floor, unsigned long ceiling)
460{
461	pud_t *pud;
462	unsigned long next;
463	unsigned long start;
464
465	start = addr;
466	pud = pud_offset(p4d, addr);
467	do {
468		next = pud_addr_end(addr, end);
469		if (pud_none_or_clear_bad(pud))
470			continue;
471		if (is_hugetlb_pud(*pud))
472			pud_clear(pud);
473		else
474			hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
475					       ceiling);
476	} while (pud++, addr = next, addr != end);
477
478	start &= PGDIR_MASK;
479	if (start < floor)
480		return;
481	if (ceiling) {
482		ceiling &= PGDIR_MASK;
483		if (!ceiling)
484			return;
485	}
486	if (end - 1 > ceiling - 1)
487		return;
488
489	pud = pud_offset(p4d, start);
490	p4d_clear(p4d);
491	pud_free_tlb(tlb, pud, start);
492	mm_dec_nr_puds(tlb->mm);
493}
494
495void hugetlb_free_pgd_range(struct mmu_gather *tlb,
496			    unsigned long addr, unsigned long end,
497			    unsigned long floor, unsigned long ceiling)
498{
499	pgd_t *pgd;
500	p4d_t *p4d;
501	unsigned long next;
502
503	addr &= PMD_MASK;
504	if (addr < floor) {
505		addr += PMD_SIZE;
506		if (!addr)
507			return;
508	}
509	if (ceiling) {
510		ceiling &= PMD_MASK;
511		if (!ceiling)
512			return;
513	}
514	if (end - 1 > ceiling - 1)
515		end -= PMD_SIZE;
516	if (addr > end - 1)
517		return;
518
519	pgd = pgd_offset(tlb->mm, addr);
520	p4d = p4d_offset(pgd, addr);
521	do {
522		next = p4d_addr_end(addr, end);
523		if (p4d_none_or_clear_bad(p4d))
524			continue;
525		hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
526	} while (p4d++, addr = next, addr != end);
527}
528