xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 5437b0ff6d557daf6c35e1307a5737139bc12f9a) 
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(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 		if (order == 0 && (flags & GFP_DMA32) == 0) {
110 			page = vm_page_alloc_noobj(req);
111 			if (page == NULL)
112 				return (NULL);
113 		} else {
114 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
115 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
116 		retry:
117 			page = vm_page_alloc_noobj_contig(req, npages, 0, pmax,
118 			    PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
119 			if (page == NULL) {
120 				if ((flags & (M_WAITOK | __GFP_NORETRY)) ==
121 				    M_WAITOK) {
122 					int err = vm_page_reclaim_contig(req,
123 					    npages, 0, pmax, PAGE_SIZE, 0);
124 					if (err == ENOMEM)
125 						vm_wait(NULL);
126 					else if (err != 0)
127 						return (NULL);
128 					flags &= ~M_WAITOK;
129 					goto retry;
130 				}
131 				return (NULL);
132 			}
133 		}
134 	} else {
135 		vm_offset_t vaddr;
136 
137 		vaddr = linux_alloc_kmem(flags, order);
138 		if (vaddr == 0)
139 			return (NULL);
140 
141 		page = virt_to_page((void *)vaddr);
142 
143 		KASSERT(vaddr == (vm_offset_t)page_address(page),
144 		    ("Page address mismatch"));
145 	}
146 
147 	return (page);
148 }
149 
150 static void
151 _linux_free_kmem(vm_offset_t addr, unsigned int order)
152 {
153 	size_t size = ((size_t)PAGE_SIZE) << order;
154 
155 	kmem_free((void *)addr, size);
156 }
157 
158 void
159 linux_free_pages(struct page *page, unsigned int order)
160 {
161 	if (PMAP_HAS_DMAP) {
162 		unsigned long npages = 1UL << order;
163 		unsigned long x;
164 
165 		for (x = 0; x != npages; x++) {
166 			vm_page_t pgo = page + x;
167 
168 			if (vm_page_unwire_noq(pgo))
169 				vm_page_free(pgo);
170 		}
171 	} else {
172 		vm_offset_t vaddr;
173 
174 		vaddr = (vm_offset_t)page_address(page);
175 
176 		_linux_free_kmem(vaddr, order);
177 	}
178 }
179 
180 vm_offset_t
181 linux_alloc_kmem(gfp_t flags, unsigned int order)
182 {
183 	size_t size = ((size_t)PAGE_SIZE) << order;
184 	void *addr;
185 
186 	addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
187 	    ((flags & GFP_DMA32) == 0) ? -1UL : BUS_SPACE_MAXADDR_32BIT,
188 	    PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
189 
190 	return ((vm_offset_t)addr);
191 }
192 
193 void
194 linux_free_kmem(vm_offset_t addr, unsigned int order)
195 {
196 	KASSERT((addr & ~PAGE_MASK) == 0,
197 	    ("%s: addr %p is not page aligned", __func__, (void *)addr));
198 
199 	if (addr >= VM_MIN_KERNEL_ADDRESS && addr < VM_MAX_KERNEL_ADDRESS) {
200 		_linux_free_kmem(addr, order);
201 	} else {
202 		vm_page_t page;
203 
204 		page = PHYS_TO_VM_PAGE(DMAP_TO_PHYS(addr));
205 		linux_free_pages(page, order);
206 	}
207 }
208 
209 static int
210 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
211     int write, struct page **pages)
212 {
213 	vm_prot_t prot;
214 	size_t len;
215 	int count;
216 
217 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
218 	len = ptoa((vm_offset_t)nr_pages);
219 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
220 	return (count == -1 ? -EFAULT : nr_pages);
221 }
222 
223 int
224 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
225     struct page **pages)
226 {
227 	vm_map_t map;
228 	vm_page_t *mp;
229 	vm_offset_t va;
230 	vm_offset_t end;
231 	vm_prot_t prot;
232 	int count;
233 
234 	if (nr_pages == 0 || in_interrupt())
235 		return (0);
236 
237 	MPASS(pages != NULL);
238 	map = &curthread->td_proc->p_vmspace->vm_map;
239 	end = start + ptoa((vm_offset_t)nr_pages);
240 	if (!vm_map_range_valid(map, start, end))
241 		return (-EINVAL);
242 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
243 	for (count = 0, mp = pages, va = start; va < end;
244 	    mp++, va += PAGE_SIZE, count++) {
245 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
246 		if (*mp == NULL)
247 			break;
248 
249 		if ((prot & VM_PROT_WRITE) != 0 &&
250 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
251 			/*
252 			 * Explicitly dirty the physical page.  Otherwise, the
253 			 * caller's changes may go unnoticed because they are
254 			 * performed through an unmanaged mapping or by a DMA
255 			 * operation.
256 			 *
257 			 * The object lock is not held here.
258 			 * See vm_page_clear_dirty_mask().
259 			 */
260 			vm_page_dirty(*mp);
261 		}
262 	}
263 	return (count);
264 }
265 
266 long
267 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
268     unsigned long start, unsigned long nr_pages, unsigned int gup_flags,
269     struct page **pages, struct vm_area_struct **vmas)
270 {
271 	vm_map_t map;
272 
273 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
274 	return (linux_get_user_pages_internal(map, start, nr_pages,
275 	    !!(gup_flags & FOLL_WRITE), pages));
276 }
277 
278 long
279 lkpi_get_user_pages(unsigned long start, unsigned long nr_pages,
280     unsigned int gup_flags, struct page **pages)
281 {
282 	vm_map_t map;
283 
284 	map = &curthread->td_proc->p_vmspace->vm_map;
285 	return (linux_get_user_pages_internal(map, start, nr_pages,
286 	    !!(gup_flags & FOLL_WRITE), pages));
287 }
288 
289 int
290 is_vmalloc_addr(const void *addr)
291 {
292 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
293 }
294 
295 vm_fault_t
296 lkpi_vmf_insert_pfn_prot_locked(struct vm_area_struct *vma, unsigned long addr,
297     unsigned long pfn, pgprot_t prot)
298 {
299 	struct pctrie_iter pages;
300 	vm_object_t vm_obj = vma->vm_obj;
301 	vm_object_t tmp_obj;
302 	vm_page_t page;
303 	vm_pindex_t pindex;
304 
305 	VM_OBJECT_ASSERT_WLOCKED(vm_obj);
306 	vm_page_iter_init(&pages, vm_obj);
307 	pindex = OFF_TO_IDX(addr - vma->vm_start);
308 	if (vma->vm_pfn_count == 0)
309 		vma->vm_pfn_first = pindex;
310 	MPASS(pindex <= OFF_TO_IDX(vma->vm_end));
311 
312 retry:
313 	page = vm_page_grab_iter(vm_obj, pindex, VM_ALLOC_NOCREAT, &pages);
314 	if (page == NULL) {
315 		page = PHYS_TO_VM_PAGE(IDX_TO_OFF(pfn));
316 		if (!vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL)) {
317 			pctrie_iter_reset(&pages);
318 			goto retry;
319 		}
320 		if (page->object != NULL) {
321 			tmp_obj = page->object;
322 			vm_page_xunbusy(page);
323 			VM_OBJECT_WUNLOCK(vm_obj);
324 			VM_OBJECT_WLOCK(tmp_obj);
325 			if (page->object == tmp_obj &&
326 			    vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL)) {
327 				KASSERT(page->object == tmp_obj,
328 				    ("page has changed identity"));
329 				KASSERT((page->oflags & VPO_UNMANAGED) == 0,
330 				    ("page does not belong to shmem"));
331 				vm_pager_page_unswapped(page);
332 				if (pmap_page_is_mapped(page)) {
333 					vm_page_xunbusy(page);
334 					VM_OBJECT_WUNLOCK(tmp_obj);
335 					printf("%s: page rename failed: page "
336 					    "is mapped\n", __func__);
337 					VM_OBJECT_WLOCK(vm_obj);
338 					return (VM_FAULT_NOPAGE);
339 				}
340 				vm_page_remove(page);
341 			}
342 			VM_OBJECT_WUNLOCK(tmp_obj);
343 			pctrie_iter_reset(&pages);
344 			VM_OBJECT_WLOCK(vm_obj);
345 			goto retry;
346 		}
347 		if (vm_page_iter_insert(page, vm_obj, pindex, &pages) != 0) {
348 			vm_page_xunbusy(page);
349 			return (VM_FAULT_OOM);
350 		}
351 		vm_page_valid(page);
352 	}
353 	pmap_page_set_memattr(page, pgprot2cachemode(prot));
354 	vma->vm_pfn_count++;
355 
356 	return (VM_FAULT_NOPAGE);
357 }
358 
359 int
360 lkpi_remap_pfn_range(struct vm_area_struct *vma, unsigned long start_addr,
361     unsigned long start_pfn, unsigned long size, pgprot_t prot)
362 {
363 	vm_object_t vm_obj;
364 	unsigned long addr, pfn;
365 	int err = 0;
366 
367 	vm_obj = vma->vm_obj;
368 
369 	VM_OBJECT_WLOCK(vm_obj);
370 	for (addr = start_addr, pfn = start_pfn;
371 	    addr < start_addr + size;
372 	    addr += PAGE_SIZE) {
373 		vm_fault_t ret;
374 retry:
375 		ret = lkpi_vmf_insert_pfn_prot_locked(vma, addr, pfn, prot);
376 
377 		if ((ret & VM_FAULT_OOM) != 0) {
378 			VM_OBJECT_WUNLOCK(vm_obj);
379 			vm_wait(NULL);
380 			VM_OBJECT_WLOCK(vm_obj);
381 			goto retry;
382 		}
383 
384 		if ((ret & VM_FAULT_ERROR) != 0) {
385 			err = -EFAULT;
386 			break;
387 		}
388 
389 		pfn++;
390 	}
391 	VM_OBJECT_WUNLOCK(vm_obj);
392 
393 	if (unlikely(err)) {
394 		zap_vma_ptes(vma, start_addr,
395 		    (pfn - start_pfn) << PAGE_SHIFT);
396 		return (err);
397 	}
398 
399 	return (0);
400 }
401 
402 int
403 lkpi_io_mapping_map_user(struct io_mapping *iomap,
404     struct vm_area_struct *vma, unsigned long addr,
405     unsigned long pfn, unsigned long size)
406 {
407 	pgprot_t prot;
408 	int ret;
409 
410 	prot = cachemode2protval(iomap->attr);
411 	ret = lkpi_remap_pfn_range(vma, addr, pfn, size, prot);
412 
413 	return (ret);
414 }
415 
416 /*
417  * Although FreeBSD version of unmap_mapping_range has semantics and types of
418  * parameters compatible with Linux version, the values passed in are different
419  * @obj should match to vm_private_data field of vm_area_struct returned by
420  *      mmap file operation handler, see linux_file_mmap_single() sources
421  * @holelen should match to size of area to be munmapped.
422  */
423 void
424 lkpi_unmap_mapping_range(void *obj, loff_t const holebegin __unused,
425     loff_t const holelen __unused, int even_cows __unused)
426 {
427 	vm_object_t devobj;
428 
429 	devobj = cdev_pager_lookup(obj);
430 	if (devobj != NULL) {
431 		cdev_mgtdev_pager_free_pages(devobj);
432 		vm_object_deallocate(devobj);
433 	}
434 }
435 
436 int
437 lkpi_arch_phys_wc_add(unsigned long base, unsigned long size)
438 {
439 #ifdef __i386__
440 	struct mem_range_desc *mrdesc;
441 	int error, id, act;
442 
443 	/* If PAT is available, do nothing */
444 	if (pat_works)
445 		return (0);
446 
447 	mrdesc = malloc(sizeof(*mrdesc), M_LKMTRR, M_WAITOK);
448 	mrdesc->mr_base = base;
449 	mrdesc->mr_len = size;
450 	mrdesc->mr_flags = MDF_WRITECOMBINE;
451 	strlcpy(mrdesc->mr_owner, "drm", sizeof(mrdesc->mr_owner));
452 	act = MEMRANGE_SET_UPDATE;
453 	error = mem_range_attr_set(mrdesc, &act);
454 	if (error == 0) {
455 		error = idr_get_new(&mtrr_idr, mrdesc, &id);
456 		MPASS(idr_find(&mtrr_idr, id) == mrdesc);
457 		if (error != 0) {
458 			act = MEMRANGE_SET_REMOVE;
459 			mem_range_attr_set(mrdesc, &act);
460 		}
461 	}
462 	if (error != 0) {
463 		free(mrdesc, M_LKMTRR);
464 		pr_warn(
465 		    "Failed to add WC MTRR for [%p-%p]: %d; "
466 		    "performance may suffer\n",
467 		    (void *)base, (void *)(base + size - 1), error);
468 	} else
469 		pr_warn("Successfully added WC MTRR for [%p-%p]\n",
470 		    (void *)base, (void *)(base + size - 1));
471 
472 	return (error != 0 ? -error : id + __MTRR_ID_BASE);
473 #else
474 	return (0);
475 #endif
476 }
477 
478 void
479 lkpi_arch_phys_wc_del(int reg)
480 {
481 #ifdef __i386__
482 	struct mem_range_desc *mrdesc;
483 	int act;
484 
485 	/* Check if arch_phys_wc_add() failed. */
486 	if (reg < __MTRR_ID_BASE)
487 		return;
488 
489 	mrdesc = idr_find(&mtrr_idr, reg - __MTRR_ID_BASE);
490 	MPASS(mrdesc != NULL);
491 	idr_remove(&mtrr_idr, reg - __MTRR_ID_BASE);
492 	act = MEMRANGE_SET_REMOVE;
493 	mem_range_attr_set(mrdesc, &act);
494 	free(mrdesc, M_LKMTRR);
495 #endif
496 }
497 
498 /*
499  * This is a highly simplified version of the Linux page_frag_cache.
500  * We only support up-to 1 single page as fragment size and we will
501  * always return a full page.  This may be wasteful on small objects
502  * but the only known consumer (mt76) is either asking for a half-page
503  * or a full page.  If this was to become a problem we can implement
504  * a more elaborate version.
505  */
506 void *
507 linuxkpi_page_frag_alloc(struct page_frag_cache *pfc,
508     size_t fragsz, gfp_t gfp)
509 {
510 	vm_page_t pages;
511 
512 	if (fragsz == 0)
513 		return (NULL);
514 
515 	KASSERT(fragsz <= PAGE_SIZE, ("%s: fragsz %zu > PAGE_SIZE not yet "
516 	    "supported", __func__, fragsz));
517 
518 	pages = alloc_pages(gfp, flsl(howmany(fragsz, PAGE_SIZE) - 1));
519 	if (pages == NULL)
520 		return (NULL);
521 	pfc->va = linux_page_address(pages);
522 
523 	/* Passed in as "count" to __page_frag_cache_drain(). Unused by us. */
524 	pfc->pagecnt_bias = 0;
525 
526 	return (pfc->va);
527 }
528 
529 void
530 linuxkpi_page_frag_free(void *addr)
531 {
532 	vm_page_t page;
533 
534 	page = virt_to_page(addr);
535 	linux_free_pages(page, 0);
536 }
537 
538 void
539 linuxkpi__page_frag_cache_drain(struct page *page, size_t count __unused)
540 {
541 
542 	linux_free_pages(page, 0);
543 }
544