xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 8c5a9161d16094d9db474fe78ddead1325246d05)
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 si_meminfo(struct sysinfo *si)
68 {
69 	si->totalram = physmem;
70 	si->totalhigh = 0;
71 	si->mem_unit = PAGE_SIZE;
72 }
73 
74 void *
75 linux_page_address(struct page *page)
76 {
77 
78 	if (page->object != kmem_object && page->object != kernel_object) {
79 		return (PMAP_HAS_DMAP ?
80 		    ((void *)(uintptr_t)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(page))) :
81 		    NULL);
82 	}
83 	return ((void *)(uintptr_t)(VM_MIN_KERNEL_ADDRESS +
84 	    IDX_TO_OFF(page->pindex)));
85 }
86 
87 vm_page_t
88 linux_alloc_pages(gfp_t flags, unsigned int order)
89 {
90 	vm_page_t page;
91 
92 	if (PMAP_HAS_DMAP) {
93 		unsigned long npages = 1UL << order;
94 		int req = VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_NORMAL;
95 
96 		if ((flags & M_ZERO) != 0)
97 			req |= VM_ALLOC_ZERO;
98 		if (order == 0 && (flags & GFP_DMA32) == 0) {
99 			page = vm_page_alloc(NULL, 0, req);
100 			if (page == NULL)
101 				return (NULL);
102 		} else {
103 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
104 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
105 		retry:
106 			page = vm_page_alloc_contig(NULL, 0, req,
107 			    npages, 0, pmax, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
108 
109 			if (page == NULL) {
110 				if (flags & M_WAITOK) {
111 					if (!vm_page_reclaim_contig(req,
112 					    npages, 0, pmax, PAGE_SIZE, 0)) {
113 						vm_wait(NULL);
114 					}
115 					flags &= ~M_WAITOK;
116 					goto retry;
117 				}
118 				return (NULL);
119 			}
120 		}
121 		if (flags & M_ZERO) {
122 			unsigned long x;
123 
124 			for (x = 0; x != npages; x++) {
125 				vm_page_t pgo = page + x;
126 
127 				if ((pgo->flags & PG_ZERO) == 0)
128 					pmap_zero_page(pgo);
129 			}
130 		}
131 	} else {
132 		vm_offset_t vaddr;
133 
134 		vaddr = linux_alloc_kmem(flags, order);
135 		if (vaddr == 0)
136 			return (NULL);
137 
138 		page = PHYS_TO_VM_PAGE(vtophys((void *)vaddr));
139 
140 		KASSERT(vaddr == (vm_offset_t)page_address(page),
141 		    ("Page address mismatch"));
142 	}
143 
144 	return (page);
145 }
146 
147 void
148 linux_free_pages(vm_page_t page, unsigned int order)
149 {
150 	if (PMAP_HAS_DMAP) {
151 		unsigned long npages = 1UL << order;
152 		unsigned long x;
153 
154 		for (x = 0; x != npages; x++) {
155 			vm_page_t pgo = page + x;
156 
157 			vm_page_lock(pgo);
158 			if (vm_page_unwire_noq(pgo))
159 				vm_page_free(pgo);
160 			vm_page_unlock(pgo);
161 		}
162 	} else {
163 		vm_offset_t vaddr;
164 
165 		vaddr = (vm_offset_t)page_address(page);
166 
167 		linux_free_kmem(vaddr, order);
168 	}
169 }
170 
171 vm_offset_t
172 linux_alloc_kmem(gfp_t flags, unsigned int order)
173 {
174 	size_t size = ((size_t)PAGE_SIZE) << order;
175 	vm_offset_t addr;
176 
177 	if ((flags & GFP_DMA32) == 0) {
178 		addr = kmem_malloc(size, flags & GFP_NATIVE_MASK);
179 	} else {
180 		addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
181 		    BUS_SPACE_MAXADDR_32BIT, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
182 	}
183 	return (addr);
184 }
185 
186 void
187 linux_free_kmem(vm_offset_t addr, unsigned int order)
188 {
189 	size_t size = ((size_t)PAGE_SIZE) << order;
190 
191 	kmem_free(addr, size);
192 }
193 
194 static int
195 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
196     int write, struct page **pages)
197 {
198 	vm_prot_t prot;
199 	size_t len;
200 	int count;
201 	int i;
202 
203 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
204 	len = ((size_t)nr_pages) << PAGE_SHIFT;
205 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
206 	if (count == -1)
207 		return (-EFAULT);
208 
209 	for (i = 0; i != nr_pages; i++) {
210 		struct page *pg = pages[i];
211 
212 		vm_page_lock(pg);
213 		vm_page_wire(pg);
214 		vm_page_unhold(pg);
215 		vm_page_unlock(pg);
216 	}
217 	return (nr_pages);
218 }
219 
220 int
221 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
222     struct page **pages)
223 {
224 	vm_map_t map;
225 	vm_page_t *mp;
226 	vm_offset_t va;
227 	vm_offset_t end;
228 	vm_prot_t prot;
229 	int count;
230 
231 	if (nr_pages == 0 || in_interrupt())
232 		return (0);
233 
234 	MPASS(pages != NULL);
235 	va = start;
236 	map = &curthread->td_proc->p_vmspace->vm_map;
237 	end = start + (((size_t)nr_pages) << PAGE_SHIFT);
238 	if (start < vm_map_min(map) || end > vm_map_max(map))
239 		return (-EINVAL);
240 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
241 	for (count = 0, mp = pages, va = start; va < end;
242 	    mp++, va += PAGE_SIZE, count++) {
243 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
244 		if (*mp == NULL)
245 			break;
246 
247 		vm_page_lock(*mp);
248 		vm_page_wire(*mp);
249 		vm_page_unhold(*mp);
250 		vm_page_unlock(*mp);
251 
252 		if ((prot & VM_PROT_WRITE) != 0 &&
253 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
254 			/*
255 			 * Explicitly dirty the physical page.  Otherwise, the
256 			 * caller's changes may go unnoticed because they are
257 			 * performed through an unmanaged mapping or by a DMA
258 			 * operation.
259 			 *
260 			 * The object lock is not held here.
261 			 * See vm_page_clear_dirty_mask().
262 			 */
263 			vm_page_dirty(*mp);
264 		}
265 	}
266 	return (count);
267 }
268 
269 long
270 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
271     unsigned long start, unsigned long nr_pages, int gup_flags,
272     struct page **pages, struct vm_area_struct **vmas)
273 {
274 	vm_map_t map;
275 
276 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
277 	return (linux_get_user_pages_internal(map, start, nr_pages,
278 	    !!(gup_flags & FOLL_WRITE), pages));
279 }
280 
281 long
282 get_user_pages(unsigned long start, unsigned long nr_pages, int gup_flags,
283     struct page **pages, struct vm_area_struct **vmas)
284 {
285 	vm_map_t map;
286 
287 	map = &curthread->td_proc->p_vmspace->vm_map;
288 	return (linux_get_user_pages_internal(map, start, nr_pages,
289 	    !!(gup_flags & FOLL_WRITE), pages));
290 }
291 
292 int
293 is_vmalloc_addr(const void *addr)
294 {
295 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
296 }
297 
298 struct page *
299 linux_shmem_read_mapping_page_gfp(vm_object_t obj, int pindex, gfp_t gfp)
300 {
301 	vm_page_t page;
302 	int rv;
303 
304 	if ((gfp & GFP_NOWAIT) != 0)
305 		panic("GFP_NOWAIT is unimplemented");
306 
307 	VM_OBJECT_WLOCK(obj);
308 	page = vm_page_grab(obj, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
309 	    VM_ALLOC_WIRED);
310 	if (page->valid != VM_PAGE_BITS_ALL) {
311 		vm_page_xbusy(page);
312 		if (vm_pager_has_page(obj, pindex, NULL, NULL)) {
313 			rv = vm_pager_get_pages(obj, &page, 1, NULL, NULL);
314 			if (rv != VM_PAGER_OK) {
315 				vm_page_lock(page);
316 				vm_page_unwire_noq(page);
317 				vm_page_free(page);
318 				vm_page_unlock(page);
319 				VM_OBJECT_WUNLOCK(obj);
320 				return (ERR_PTR(-EINVAL));
321 			}
322 			MPASS(page->valid == VM_PAGE_BITS_ALL);
323 		} else {
324 			pmap_zero_page(page);
325 			page->valid = VM_PAGE_BITS_ALL;
326 			page->dirty = 0;
327 		}
328 		vm_page_xunbusy(page);
329 	}
330 	VM_OBJECT_WUNLOCK(obj);
331 	return (page);
332 }
333 
334 struct linux_file *
335 linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
336 {
337 	struct fileobj {
338 		struct linux_file file __aligned(sizeof(void *));
339 		struct vnode vnode __aligned(sizeof(void *));
340 	};
341 	struct fileobj *fileobj;
342 	struct linux_file *filp;
343 	struct vnode *vp;
344 	int error;
345 
346 	fileobj = kzalloc(sizeof(*fileobj), GFP_KERNEL);
347 	if (fileobj == NULL) {
348 		error = -ENOMEM;
349 		goto err_0;
350 	}
351 	filp = &fileobj->file;
352 	vp = &fileobj->vnode;
353 
354 	filp->f_count = 1;
355 	filp->f_vnode = vp;
356 	filp->f_shmem = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
357 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
358 	if (filp->f_shmem == NULL) {
359 		error = -ENOMEM;
360 		goto err_1;
361 	}
362 	return (filp);
363 err_1:
364 	kfree(filp);
365 err_0:
366 	return (ERR_PTR(error));
367 }
368 
369 static vm_ooffset_t
370 linux_invalidate_mapping_pages_sub(vm_object_t obj, vm_pindex_t start,
371     vm_pindex_t end, int flags)
372 {
373 	int start_count, end_count;
374 
375 	VM_OBJECT_WLOCK(obj);
376 	start_count = obj->resident_page_count;
377 	vm_object_page_remove(obj, start, end, flags);
378 	end_count = obj->resident_page_count;
379 	VM_OBJECT_WUNLOCK(obj);
380 	return (start_count - end_count);
381 }
382 
383 unsigned long
384 linux_invalidate_mapping_pages(vm_object_t obj, pgoff_t start, pgoff_t end)
385 {
386 
387 	return (linux_invalidate_mapping_pages_sub(obj, start, end, OBJPR_CLEANONLY));
388 }
389 
390 void
391 linux_shmem_truncate_range(vm_object_t obj, loff_t lstart, loff_t lend)
392 {
393 	vm_pindex_t start = OFF_TO_IDX(lstart + PAGE_SIZE - 1);
394 	vm_pindex_t end = OFF_TO_IDX(lend + 1);
395 
396 	(void) linux_invalidate_mapping_pages_sub(obj, start, end, 0);
397 }
398