xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision e4456411a8c2d4a9bfbccd60f2cf914fd402f817)
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/rwlock.h>
40 #include <sys/proc.h>
41 #include <sys/sched.h>
42 
43 #include <machine/bus.h>
44 
45 #include <vm/vm.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_param.h>
48 #include <vm/vm_kern.h>
49 #include <vm/vm_object.h>
50 #include <vm/vm_map.h>
51 #include <vm/vm_page.h>
52 #include <vm/vm_pageout.h>
53 #include <vm/vm_pager.h>
54 #include <vm/vm_radix.h>
55 #include <vm/vm_reserv.h>
56 #include <vm/vm_extern.h>
57 
58 #include <vm/uma.h>
59 #include <vm/uma_int.h>
60 
61 #include <linux/gfp.h>
62 #include <linux/mm.h>
63 #include <linux/preempt.h>
64 #include <linux/fs.h>
65 
66 void *
67 linux_page_address(struct page *page)
68 {
69 
70 	if (page->object != kmem_object && page->object != kernel_object) {
71 		return (PMAP_HAS_DMAP ?
72 		    ((void *)(uintptr_t)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(page))) :
73 		    NULL);
74 	}
75 	return ((void *)(uintptr_t)(VM_MIN_KERNEL_ADDRESS +
76 	    IDX_TO_OFF(page->pindex)));
77 }
78 
79 vm_page_t
80 linux_alloc_pages(gfp_t flags, unsigned int order)
81 {
82 	vm_page_t page;
83 
84 	if (PMAP_HAS_DMAP) {
85 		unsigned long npages = 1UL << order;
86 		int req = (flags & M_ZERO) ? (VM_ALLOC_ZERO | VM_ALLOC_NOOBJ |
87 		    VM_ALLOC_NORMAL) : (VM_ALLOC_NOOBJ | VM_ALLOC_NORMAL);
88 
89 		if (order == 0 && (flags & GFP_DMA32) == 0) {
90 			page = vm_page_alloc(NULL, 0, req);
91 			if (page == NULL)
92 				return (NULL);
93 		} else {
94 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
95 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
96 		retry:
97 			page = vm_page_alloc_contig(NULL, 0, req,
98 			    npages, 0, pmax, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
99 
100 			if (page == NULL) {
101 				if (flags & M_WAITOK) {
102 					if (!vm_page_reclaim_contig(req,
103 					    npages, 0, pmax, PAGE_SIZE, 0)) {
104 						vm_wait(NULL);
105 					}
106 					flags &= ~M_WAITOK;
107 					goto retry;
108 				}
109 				return (NULL);
110 			}
111 		}
112 		if (flags & M_ZERO) {
113 			unsigned long x;
114 
115 			for (x = 0; x != npages; x++) {
116 				vm_page_t pgo = page + x;
117 
118 				if ((pgo->flags & PG_ZERO) == 0)
119 					pmap_zero_page(pgo);
120 			}
121 		}
122 	} else {
123 		vm_offset_t vaddr;
124 
125 		vaddr = linux_alloc_kmem(flags, order);
126 		if (vaddr == 0)
127 			return (NULL);
128 
129 		page = PHYS_TO_VM_PAGE(vtophys((void *)vaddr));
130 
131 		KASSERT(vaddr == (vm_offset_t)page_address(page),
132 		    ("Page address mismatch"));
133 	}
134 
135 	return (page);
136 }
137 
138 void
139 linux_free_pages(vm_page_t page, unsigned int order)
140 {
141 	if (PMAP_HAS_DMAP) {
142 		unsigned long npages = 1UL << order;
143 		unsigned long x;
144 
145 		for (x = 0; x != npages; x++) {
146 			vm_page_t pgo = page + x;
147 
148 			vm_page_lock(pgo);
149 			vm_page_free(pgo);
150 			vm_page_unlock(pgo);
151 		}
152 	} else {
153 		vm_offset_t vaddr;
154 
155 		vaddr = (vm_offset_t)page_address(page);
156 
157 		linux_free_kmem(vaddr, order);
158 	}
159 }
160 
161 vm_offset_t
162 linux_alloc_kmem(gfp_t flags, unsigned int order)
163 {
164 	size_t size = ((size_t)PAGE_SIZE) << order;
165 	vm_offset_t addr;
166 
167 	if ((flags & GFP_DMA32) == 0) {
168 		addr = kmem_malloc(size, flags & GFP_NATIVE_MASK);
169 	} else {
170 		addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
171 		    BUS_SPACE_MAXADDR_32BIT, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
172 	}
173 	return (addr);
174 }
175 
176 void
177 linux_free_kmem(vm_offset_t addr, unsigned int order)
178 {
179 	size_t size = ((size_t)PAGE_SIZE) << order;
180 
181 	kmem_free(addr, size);
182 }
183 
184 static int
185 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
186     int write, struct page **pages)
187 {
188 	vm_prot_t prot;
189 	size_t len;
190 	int count;
191 	int i;
192 
193 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
194 	len = ((size_t)nr_pages) << PAGE_SHIFT;
195 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
196 	if (count == -1)
197 		return (-EFAULT);
198 
199 	for (i = 0; i != nr_pages; i++) {
200 		struct page *pg = pages[i];
201 
202 		vm_page_lock(pg);
203 		vm_page_wire(pg);
204 		vm_page_unhold(pg);
205 		vm_page_unlock(pg);
206 	}
207 	return (nr_pages);
208 }
209 
210 int
211 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
212     struct page **pages)
213 {
214 	vm_map_t map;
215 	vm_page_t *mp;
216 	vm_offset_t va;
217 	vm_offset_t end;
218 	vm_prot_t prot;
219 	int count;
220 
221 	if (nr_pages == 0 || in_interrupt())
222 		return (0);
223 
224 	MPASS(pages != NULL);
225 	va = start;
226 	map = &curthread->td_proc->p_vmspace->vm_map;
227 	end = start + (((size_t)nr_pages) << PAGE_SHIFT);
228 	if (start < vm_map_min(map) || end > vm_map_max(map))
229 		return (-EINVAL);
230 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
231 	for (count = 0, mp = pages, va = start; va < end;
232 	    mp++, va += PAGE_SIZE, count++) {
233 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
234 		if (*mp == NULL)
235 			break;
236 
237 		vm_page_lock(*mp);
238 		vm_page_wire(*mp);
239 		vm_page_unhold(*mp);
240 		vm_page_unlock(*mp);
241 
242 		if ((prot & VM_PROT_WRITE) != 0 &&
243 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
244 			/*
245 			 * Explicitly dirty the physical page.  Otherwise, the
246 			 * caller's changes may go unnoticed because they are
247 			 * performed through an unmanaged mapping or by a DMA
248 			 * operation.
249 			 *
250 			 * The object lock is not held here.
251 			 * See vm_page_clear_dirty_mask().
252 			 */
253 			vm_page_dirty(*mp);
254 		}
255 	}
256 	return (count);
257 }
258 
259 long
260 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
261     unsigned long start, unsigned long nr_pages, int gup_flags,
262     struct page **pages, struct vm_area_struct **vmas)
263 {
264 	vm_map_t map;
265 
266 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
267 	return (linux_get_user_pages_internal(map, start, nr_pages,
268 	    !!(gup_flags & FOLL_WRITE), pages));
269 }
270 
271 long
272 get_user_pages(unsigned long start, unsigned long nr_pages, int gup_flags,
273     struct page **pages, struct vm_area_struct **vmas)
274 {
275 	vm_map_t map;
276 
277 	map = &curthread->td_proc->p_vmspace->vm_map;
278 	return (linux_get_user_pages_internal(map, start, nr_pages,
279 	    !!(gup_flags & FOLL_WRITE), pages));
280 }
281 
282 int
283 is_vmalloc_addr(const void *addr)
284 {
285 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
286 }
287 
288 struct page *
289 linux_shmem_read_mapping_page_gfp(vm_object_t obj, int pindex, gfp_t gfp)
290 {
291 	vm_page_t page;
292 	int rv;
293 
294 	if ((gfp & GFP_NOWAIT) != 0)
295 		panic("GFP_NOWAIT is unimplemented");
296 
297 	VM_OBJECT_WLOCK(obj);
298 	page = vm_page_grab(obj, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
299 	    VM_ALLOC_WIRED);
300 	if (page->valid != VM_PAGE_BITS_ALL) {
301 		vm_page_xbusy(page);
302 		if (vm_pager_has_page(obj, pindex, NULL, NULL)) {
303 			rv = vm_pager_get_pages(obj, &page, 1, NULL, NULL);
304 			if (rv != VM_PAGER_OK) {
305 				vm_page_lock(page);
306 				vm_page_unwire(page, PQ_NONE);
307 				vm_page_free(page);
308 				vm_page_unlock(page);
309 				VM_OBJECT_WUNLOCK(obj);
310 				return (ERR_PTR(-EINVAL));
311 			}
312 			MPASS(page->valid == VM_PAGE_BITS_ALL);
313 		} else {
314 			pmap_zero_page(page);
315 			page->valid = VM_PAGE_BITS_ALL;
316 			page->dirty = 0;
317 		}
318 		vm_page_xunbusy(page);
319 	}
320 	VM_OBJECT_WUNLOCK(obj);
321 	return (page);
322 }
323 
324 struct linux_file *
325 linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
326 {
327 	struct fileobj {
328 		struct linux_file file __aligned(sizeof(void *));
329 		struct vnode vnode __aligned(sizeof(void *));
330 	};
331 	struct fileobj *fileobj;
332 	struct linux_file *filp;
333 	struct vnode *vp;
334 	int error;
335 
336 	fileobj = kzalloc(sizeof(*fileobj), GFP_KERNEL);
337 	if (fileobj == NULL) {
338 		error = -ENOMEM;
339 		goto err_0;
340 	}
341 	filp = &fileobj->file;
342 	vp = &fileobj->vnode;
343 
344 	filp->f_count = 1;
345 	filp->f_vnode = vp;
346 	filp->f_shmem = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
347 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
348 	if (filp->f_shmem == NULL) {
349 		error = -ENOMEM;
350 		goto err_1;
351 	}
352 	return (filp);
353 err_1:
354 	kfree(filp);
355 err_0:
356 	return (ERR_PTR(error));
357 }
358 
359 static vm_ooffset_t
360 linux_invalidate_mapping_pages_sub(vm_object_t obj, vm_pindex_t start,
361     vm_pindex_t end, int flags)
362 {
363 	int start_count, end_count;
364 
365 	VM_OBJECT_WLOCK(obj);
366 	start_count = obj->resident_page_count;
367 	vm_object_page_remove(obj, start, end, flags);
368 	end_count = obj->resident_page_count;
369 	VM_OBJECT_WUNLOCK(obj);
370 	return (start_count - end_count);
371 }
372 
373 unsigned long
374 linux_invalidate_mapping_pages(vm_object_t obj, pgoff_t start, pgoff_t end)
375 {
376 
377 	return (linux_invalidate_mapping_pages_sub(obj, start, end, OBJPR_CLEANONLY));
378 }
379 
380 void
381 linux_shmem_truncate_range(vm_object_t obj, loff_t lstart, loff_t lend)
382 {
383 	vm_pindex_t start = OFF_TO_IDX(lstart + PAGE_SIZE - 1);
384 	vm_pindex_t end = OFF_TO_IDX(lend + 1);
385 
386 	(void) linux_invalidate_mapping_pages_sub(obj, start, end, 0);
387 }
388