xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 086ce467adec42d58414fdb4d54c2b6819cf0c07) 
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2016 Matthew Macy (mmacy@mattmacy.io)
4  * Copyright (c) 2017 Mellanox Technologies, Ltd.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/malloc.h>
32 #include <sys/kernel.h>
33 #include <sys/sysctl.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/rwlock.h>
37 #include <sys/proc.h>
38 #include <sys/sched.h>
39 #include <sys/memrange.h>
40 
41 #include <machine/bus.h>
42 
43 #include <vm/vm.h>
44 #include <vm/pmap.h>
45 #include <vm/vm_param.h>
46 #include <vm/vm_kern.h>
47 #include <vm/vm_object.h>
48 #include <vm/vm_map.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pageout.h>
51 #include <vm/vm_pager.h>
52 #include <vm/vm_radix.h>
53 #include <vm/vm_reserv.h>
54 #include <vm/vm_extern.h>
55 
56 #include <vm/uma.h>
57 #include <vm/uma_int.h>
58 
59 #include <linux/gfp.h>
60 #include <linux/mm.h>
61 #include <linux/preempt.h>
62 #include <linux/fs.h>
63 #include <linux/shmem_fs.h>
64 #include <linux/kernel.h>
65 #include <linux/idr.h>
66 #include <linux/io.h>
67 #include <linux/io-mapping.h>
68 
69 #ifdef __i386__
70 DEFINE_IDR(mtrr_idr);
71 static MALLOC_DEFINE(M_LKMTRR, "idr", "Linux MTRR compat");
72 extern int pat_works;
73 #endif
74 
75 void
76 si_meminfo(struct sysinfo *si)
77 {
78 	si->totalram = physmem;
79 	si->freeram = vm_free_count();
80 	si->totalhigh = 0;
81 	si->freehigh = 0;
82 	si->mem_unit = PAGE_SIZE;
83 }
84 
85 void *
86 linux_page_address(const struct page *page)
87 {
88 
89 	if (page->object != kernel_object) {
90 		return (PMAP_HAS_DMAP ?
91 		    ((void *)(uintptr_t)PHYS_TO_DMAP(page_to_phys(page))) :
92 		    NULL);
93 	}
94 	return ((void *)(uintptr_t)(VM_MIN_KERNEL_ADDRESS +
95 	    IDX_TO_OFF(page->pindex)));
96 }
97 
98 struct page *
99 linux_alloc_pages(gfp_t flags, unsigned int order)
100 {
101 	struct page *page;
102 
103 	if (PMAP_HAS_DMAP) {
104 		unsigned long npages = 1UL << order;
105 		int req = VM_ALLOC_WIRED;
106 
107 		if ((flags & M_ZERO) != 0)
108 			req |= VM_ALLOC_ZERO;
109 
110 		if (order == 0 && (flags & GFP_DMA32) == 0) {
111 			page = vm_page_alloc_noobj(req);
112 			if (page == NULL)
113 				return (NULL);
114 		} else {
115 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
116 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
117 
118 			if ((flags & __GFP_NORETRY) != 0)
119 				req |= VM_ALLOC_NORECLAIM;
120 
121 		retry:
122 			page = vm_page_alloc_noobj_contig(req, npages, 0, pmax,
123 			    PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
124 			if (page == NULL) {
125 				if ((flags & (M_WAITOK | __GFP_NORETRY)) ==
126 				    M_WAITOK) {
127 					int err = vm_page_reclaim_contig(req,
128 					    npages, 0, pmax, PAGE_SIZE, 0);
129 					if (err == ENOMEM)
130 						vm_wait(NULL);
131 					else if (err != 0)
132 						return (NULL);
133 					flags &= ~M_WAITOK;
134 					goto retry;
135 				}
136 				return (NULL);
137 			}
138 		}
139 	} else {
140 		vm_offset_t vaddr;
141 
142 		vaddr = linux_alloc_kmem(flags, order);
143 		if (vaddr == 0)
144 			return (NULL);
145 
146 		page = virt_to_page((void *)vaddr);
147 
148 		KASSERT(vaddr == (vm_offset_t)page_address(page),
149 		    ("Page address mismatch"));
150 	}
151 
152 	return (page);
153 }
154 
155 static void
156 _linux_free_kmem(vm_offset_t addr, unsigned int order)
157 {
158 	size_t size = ((size_t)PAGE_SIZE) << order;
159 
160 	kmem_free((void *)addr, size);
161 }
162 
163 void
164 linux_free_pages(struct page *page, unsigned int order)
165 {
166 	if (PMAP_HAS_DMAP) {
167 		unsigned long npages = 1UL << order;
168 		unsigned long x;
169 
170 		for (x = 0; x != npages; x++) {
171 			vm_page_t pgo = page + x;
172 
173 			/*
174 			 * The "free page" function is used in several
175 			 * contexts.
176 			 *
177 			 * Some pages are allocated by `linux_alloc_pages()`
178 			 * above, but not all of them are. For instance in the
179 			 * DRM drivers, some pages come from
180 			 * `shmem_read_mapping_page_gfp()`.
181 			 *
182 			 * That's why we need to check if the page is managed
183 			 * or not here.
184 			 */
185 			if ((pgo->oflags & VPO_UNMANAGED) == 0) {
186 				vm_page_unwire(pgo, PQ_ACTIVE);
187 			} else {
188 				if (vm_page_unwire_noq(pgo))
189 					vm_page_free(pgo);
190 			}
191 		}
192 	} else {
193 		vm_offset_t vaddr;
194 
195 		vaddr = (vm_offset_t)page_address(page);
196 
197 		_linux_free_kmem(vaddr, order);
198 	}
199 }
200 
201 void
202 linux_release_pages(release_pages_arg arg, int nr)
203 {
204 	int i;
205 
206 	CTASSERT(offsetof(struct folio, page) == 0);
207 
208 	for (i = 0; i < nr; i++)
209 		__free_page(arg.pages[i]);
210 }
211 
212 vm_offset_t
213 linux_alloc_kmem(gfp_t flags, unsigned int order)
214 {
215 	size_t size = ((size_t)PAGE_SIZE) << order;
216 	void *addr;
217 
218 	addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
219 	    ((flags & GFP_DMA32) == 0) ? -1UL : BUS_SPACE_MAXADDR_32BIT,
220 	    PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
221 
222 	return ((vm_offset_t)addr);
223 }
224 
225 void
226 linux_free_kmem(vm_offset_t addr, unsigned int order)
227 {
228 	KASSERT((addr & ~PAGE_MASK) == 0,
229 	    ("%s: addr %p is not page aligned", __func__, (void *)addr));
230 
231 	if (addr >= VM_MIN_KERNEL_ADDRESS && addr < VM_MAX_KERNEL_ADDRESS) {
232 		_linux_free_kmem(addr, order);
233 	} else {
234 		vm_page_t page;
235 
236 		page = PHYS_TO_VM_PAGE(DMAP_TO_PHYS(addr));
237 		linux_free_pages(page, order);
238 	}
239 }
240 
241 static int
242 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
243     int write, struct page **pages)
244 {
245 	vm_prot_t prot;
246 	size_t len;
247 	int count;
248 
249 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
250 	len = ptoa((vm_offset_t)nr_pages);
251 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
252 	return (count == -1 ? -EFAULT : nr_pages);
253 }
254 
255 int
256 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
257     struct page **pages)
258 {
259 	vm_map_t map;
260 	vm_page_t *mp;
261 	vm_offset_t va;
262 	vm_offset_t end;
263 	vm_prot_t prot;
264 	int count;
265 
266 	if (nr_pages == 0 || in_interrupt())
267 		return (0);
268 
269 	MPASS(pages != NULL);
270 	map = &curthread->td_proc->p_vmspace->vm_map;
271 	end = start + ptoa((vm_offset_t)nr_pages);
272 	if (!vm_map_range_valid(map, start, end))
273 		return (-EINVAL);
274 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
275 	for (count = 0, mp = pages, va = start; va < end;
276 	    mp++, va += PAGE_SIZE, count++) {
277 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
278 		if (*mp == NULL)
279 			break;
280 
281 		if ((prot & VM_PROT_WRITE) != 0 &&
282 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
283 			/*
284 			 * Explicitly dirty the physical page.  Otherwise, the
285 			 * caller's changes may go unnoticed because they are
286 			 * performed through an unmanaged mapping or by a DMA
287 			 * operation.
288 			 *
289 			 * The object lock is not held here.
290 			 * See vm_page_clear_dirty_mask().
291 			 */
292 			vm_page_dirty(*mp);
293 		}
294 	}
295 	return (count);
296 }
297 
298 long
299 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
300     unsigned long start, unsigned long nr_pages, unsigned int gup_flags,
301     struct page **pages, struct vm_area_struct **vmas)
302 {
303 	vm_map_t map;
304 
305 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
306 	return (linux_get_user_pages_internal(map, start, nr_pages,
307 	    !!(gup_flags & FOLL_WRITE), pages));
308 }
309 
310 long
311 lkpi_get_user_pages(unsigned long start, unsigned long nr_pages,
312     unsigned int gup_flags, struct page **pages)
313 {
314 	vm_map_t map;
315 
316 	map = &curthread->td_proc->p_vmspace->vm_map;
317 	return (linux_get_user_pages_internal(map, start, nr_pages,
318 	    !!(gup_flags & FOLL_WRITE), pages));
319 }
320 
321 int
322 is_vmalloc_addr(const void *addr)
323 {
324 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
325 }
326 
327 vm_fault_t
328 lkpi_vmf_insert_pfn_prot_locked(struct vm_area_struct *vma, unsigned long addr,
329     unsigned long pfn, pgprot_t prot)
330 {
331 	struct pctrie_iter pages;
332 	vm_object_t vm_obj = vma->vm_obj;
333 	vm_object_t tmp_obj;
334 	vm_page_t page;
335 	vm_pindex_t pindex;
336 
337 	VM_OBJECT_ASSERT_WLOCKED(vm_obj);
338 	vm_page_iter_init(&pages, vm_obj);
339 	pindex = OFF_TO_IDX(addr - vma->vm_start);
340 	if (vma->vm_pfn_count == 0)
341 		vma->vm_pfn_first = pindex;
342 	MPASS(pindex <= OFF_TO_IDX(vma->vm_end));
343 
344 retry:
345 	page = vm_page_grab_iter(vm_obj, pindex, VM_ALLOC_NOCREAT, &pages);
346 	if (page == NULL) {
347 		page = PHYS_TO_VM_PAGE(IDX_TO_OFF(pfn));
348 		if (!vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL)) {
349 			pctrie_iter_reset(&pages);
350 			goto retry;
351 		}
352 		if (page->object != NULL) {
353 			tmp_obj = page->object;
354 			vm_page_xunbusy(page);
355 			VM_OBJECT_WUNLOCK(vm_obj);
356 			VM_OBJECT_WLOCK(tmp_obj);
357 			if (page->object == tmp_obj &&
358 			    vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL)) {
359 				KASSERT(page->object == tmp_obj,
360 				    ("page has changed identity"));
361 				KASSERT((page->oflags & VPO_UNMANAGED) == 0,
362 				    ("page does not belong to shmem"));
363 				vm_pager_page_unswapped(page);
364 				if (pmap_page_is_mapped(page)) {
365 					vm_page_xunbusy(page);
366 					VM_OBJECT_WUNLOCK(tmp_obj);
367 					printf("%s: page rename failed: page "
368 					    "is mapped\n", __func__);
369 					VM_OBJECT_WLOCK(vm_obj);
370 					return (VM_FAULT_NOPAGE);
371 				}
372 				vm_page_remove(page);
373 			}
374 			VM_OBJECT_WUNLOCK(tmp_obj);
375 			pctrie_iter_reset(&pages);
376 			VM_OBJECT_WLOCK(vm_obj);
377 			goto retry;
378 		}
379 		if (vm_page_iter_insert(page, vm_obj, pindex, &pages) != 0) {
380 			vm_page_xunbusy(page);
381 			return (VM_FAULT_OOM);
382 		}
383 		vm_page_valid(page);
384 	}
385 	pmap_page_set_memattr(page, pgprot2cachemode(prot));
386 	vma->vm_pfn_count++;
387 
388 	return (VM_FAULT_NOPAGE);
389 }
390 
391 int
392 lkpi_remap_pfn_range(struct vm_area_struct *vma, unsigned long start_addr,
393     unsigned long start_pfn, unsigned long size, pgprot_t prot)
394 {
395 	vm_object_t vm_obj;
396 	unsigned long addr, pfn;
397 	int err = 0;
398 
399 	vm_obj = vma->vm_obj;
400 
401 	VM_OBJECT_WLOCK(vm_obj);
402 	for (addr = start_addr, pfn = start_pfn;
403 	    addr < start_addr + size;
404 	    addr += PAGE_SIZE) {
405 		vm_fault_t ret;
406 retry:
407 		ret = lkpi_vmf_insert_pfn_prot_locked(vma, addr, pfn, prot);
408 
409 		if ((ret & VM_FAULT_OOM) != 0) {
410 			VM_OBJECT_WUNLOCK(vm_obj);
411 			vm_wait(NULL);
412 			VM_OBJECT_WLOCK(vm_obj);
413 			goto retry;
414 		}
415 
416 		if ((ret & VM_FAULT_ERROR) != 0) {
417 			err = -EFAULT;
418 			break;
419 		}
420 
421 		pfn++;
422 	}
423 	VM_OBJECT_WUNLOCK(vm_obj);
424 
425 	if (unlikely(err)) {
426 		zap_vma_ptes(vma, start_addr,
427 		    (pfn - start_pfn) << PAGE_SHIFT);
428 		return (err);
429 	}
430 
431 	return (0);
432 }
433 
434 int
435 lkpi_io_mapping_map_user(struct io_mapping *iomap,
436     struct vm_area_struct *vma, unsigned long addr,
437     unsigned long pfn, unsigned long size)
438 {
439 	pgprot_t prot;
440 	int ret;
441 
442 	prot = cachemode2protval(iomap->attr);
443 	ret = lkpi_remap_pfn_range(vma, addr, pfn, size, prot);
444 
445 	return (ret);
446 }
447 
448 /*
449  * Although FreeBSD version of unmap_mapping_range has semantics and types of
450  * parameters compatible with Linux version, the values passed in are different
451  * @obj should match to vm_private_data field of vm_area_struct returned by
452  *      mmap file operation handler, see linux_file_mmap_single() sources
453  * @holelen should match to size of area to be munmapped.
454  */
455 void
456 lkpi_unmap_mapping_range(void *obj, loff_t const holebegin __unused,
457     loff_t const holelen __unused, int even_cows __unused)
458 {
459 	vm_object_t devobj;
460 
461 	devobj = cdev_pager_lookup(obj);
462 	if (devobj != NULL) {
463 		cdev_mgtdev_pager_free_pages(devobj);
464 		vm_object_deallocate(devobj);
465 	}
466 }
467 
468 int
469 lkpi_arch_phys_wc_add(unsigned long base, unsigned long size)
470 {
471 #ifdef __i386__
472 	struct mem_range_desc *mrdesc;
473 	int error, id, act;
474 
475 	/* If PAT is available, do nothing */
476 	if (pat_works)
477 		return (0);
478 
479 	mrdesc = malloc(sizeof(*mrdesc), M_LKMTRR, M_WAITOK);
480 	mrdesc->mr_base = base;
481 	mrdesc->mr_len = size;
482 	mrdesc->mr_flags = MDF_WRITECOMBINE;
483 	strlcpy(mrdesc->mr_owner, "drm", sizeof(mrdesc->mr_owner));
484 	act = MEMRANGE_SET_UPDATE;
485 	error = mem_range_attr_set(mrdesc, &act);
486 	if (error == 0) {
487 		error = idr_get_new(&mtrr_idr, mrdesc, &id);
488 		MPASS(idr_find(&mtrr_idr, id) == mrdesc);
489 		if (error != 0) {
490 			act = MEMRANGE_SET_REMOVE;
491 			mem_range_attr_set(mrdesc, &act);
492 		}
493 	}
494 	if (error != 0) {
495 		free(mrdesc, M_LKMTRR);
496 		pr_warn(
497 		    "Failed to add WC MTRR for [%p-%p]: %d; "
498 		    "performance may suffer\n",
499 		    (void *)base, (void *)(base + size - 1), error);
500 	} else
501 		pr_warn("Successfully added WC MTRR for [%p-%p]\n",
502 		    (void *)base, (void *)(base + size - 1));
503 
504 	return (error != 0 ? -error : id + __MTRR_ID_BASE);
505 #else
506 	return (0);
507 #endif
508 }
509 
510 void
511 lkpi_arch_phys_wc_del(int reg)
512 {
513 #ifdef __i386__
514 	struct mem_range_desc *mrdesc;
515 	int act;
516 
517 	/* Check if arch_phys_wc_add() failed. */
518 	if (reg < __MTRR_ID_BASE)
519 		return;
520 
521 	mrdesc = idr_find(&mtrr_idr, reg - __MTRR_ID_BASE);
522 	MPASS(mrdesc != NULL);
523 	idr_remove(&mtrr_idr, reg - __MTRR_ID_BASE);
524 	act = MEMRANGE_SET_REMOVE;
525 	mem_range_attr_set(mrdesc, &act);
526 	free(mrdesc, M_LKMTRR);
527 #endif
528 }
529 
530 /*
531  * This is a highly simplified version of the Linux page_frag_cache.
532  * We only support up-to 1 single page as fragment size and we will
533  * always return a full page.  This may be wasteful on small objects
534  * but the only known consumer (mt76) is either asking for a half-page
535  * or a full page.  If this was to become a problem we can implement
536  * a more elaborate version.
537  */
538 void *
539 linuxkpi_page_frag_alloc(struct page_frag_cache *pfc,
540     size_t fragsz, gfp_t gfp)
541 {
542 	vm_page_t pages;
543 
544 	if (fragsz == 0)
545 		return (NULL);
546 
547 	KASSERT(fragsz <= PAGE_SIZE, ("%s: fragsz %zu > PAGE_SIZE not yet "
548 	    "supported", __func__, fragsz));
549 
550 	pages = alloc_pages(gfp, flsl(howmany(fragsz, PAGE_SIZE) - 1));
551 	if (pages == NULL)
552 		return (NULL);
553 	pfc->va = linux_page_address(pages);
554 
555 	/* Passed in as "count" to __page_frag_cache_drain(). Unused by us. */
556 	pfc->pagecnt_bias = 0;
557 
558 	return (pfc->va);
559 }
560 
561 void
562 linuxkpi_page_frag_free(void *addr)
563 {
564 	vm_page_t page;
565 
566 	page = virt_to_page(addr);
567 	linux_free_pages(page, 0);
568 }
569 
570 void
571 linuxkpi__page_frag_cache_drain(struct page *page, size_t count __unused)
572 {
573 
574 	linux_free_pages(page, 0);
575 }
576