xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 86aa9539fef591a363b06a0ebd3aa7a07f4c1579)
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 
202 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
203 	len = ((size_t)nr_pages) << PAGE_SHIFT;
204 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
205 	return (count == -1 ? -EFAULT : nr_pages);
206 }
207 
208 int
209 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
210     struct page **pages)
211 {
212 	vm_map_t map;
213 	vm_page_t *mp;
214 	vm_offset_t va;
215 	vm_offset_t end;
216 	vm_prot_t prot;
217 	int count;
218 
219 	if (nr_pages == 0 || in_interrupt())
220 		return (0);
221 
222 	MPASS(pages != NULL);
223 	va = start;
224 	map = &curthread->td_proc->p_vmspace->vm_map;
225 	end = start + (((size_t)nr_pages) << PAGE_SHIFT);
226 	if (start < vm_map_min(map) || end > vm_map_max(map))
227 		return (-EINVAL);
228 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
229 	for (count = 0, mp = pages, va = start; va < end;
230 	    mp++, va += PAGE_SIZE, count++) {
231 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
232 		if (*mp == NULL)
233 			break;
234 
235 		if ((prot & VM_PROT_WRITE) != 0 &&
236 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
237 			/*
238 			 * Explicitly dirty the physical page.  Otherwise, the
239 			 * caller's changes may go unnoticed because they are
240 			 * performed through an unmanaged mapping or by a DMA
241 			 * operation.
242 			 *
243 			 * The object lock is not held here.
244 			 * See vm_page_clear_dirty_mask().
245 			 */
246 			vm_page_dirty(*mp);
247 		}
248 	}
249 	return (count);
250 }
251 
252 long
253 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
254     unsigned long start, unsigned long nr_pages, int gup_flags,
255     struct page **pages, struct vm_area_struct **vmas)
256 {
257 	vm_map_t map;
258 
259 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
260 	return (linux_get_user_pages_internal(map, start, nr_pages,
261 	    !!(gup_flags & FOLL_WRITE), pages));
262 }
263 
264 long
265 get_user_pages(unsigned long start, unsigned long nr_pages, int gup_flags,
266     struct page **pages, struct vm_area_struct **vmas)
267 {
268 	vm_map_t map;
269 
270 	map = &curthread->td_proc->p_vmspace->vm_map;
271 	return (linux_get_user_pages_internal(map, start, nr_pages,
272 	    !!(gup_flags & FOLL_WRITE), pages));
273 }
274 
275 int
276 is_vmalloc_addr(const void *addr)
277 {
278 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
279 }
280 
281 struct page *
282 linux_shmem_read_mapping_page_gfp(vm_object_t obj, int pindex, gfp_t gfp)
283 {
284 	vm_page_t page;
285 	int rv;
286 
287 	if ((gfp & GFP_NOWAIT) != 0)
288 		panic("GFP_NOWAIT is unimplemented");
289 
290 	VM_OBJECT_WLOCK(obj);
291 	page = vm_page_grab(obj, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
292 	    VM_ALLOC_WIRED);
293 	if (page->valid != VM_PAGE_BITS_ALL) {
294 		vm_page_xbusy(page);
295 		if (vm_pager_has_page(obj, pindex, NULL, NULL)) {
296 			rv = vm_pager_get_pages(obj, &page, 1, NULL, NULL);
297 			if (rv != VM_PAGER_OK) {
298 				vm_page_lock(page);
299 				vm_page_unwire_noq(page);
300 				vm_page_free(page);
301 				vm_page_unlock(page);
302 				VM_OBJECT_WUNLOCK(obj);
303 				return (ERR_PTR(-EINVAL));
304 			}
305 			MPASS(page->valid == VM_PAGE_BITS_ALL);
306 		} else {
307 			pmap_zero_page(page);
308 			page->valid = VM_PAGE_BITS_ALL;
309 			page->dirty = 0;
310 		}
311 		vm_page_xunbusy(page);
312 	}
313 	VM_OBJECT_WUNLOCK(obj);
314 	return (page);
315 }
316 
317 struct linux_file *
318 linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
319 {
320 	struct fileobj {
321 		struct linux_file file __aligned(sizeof(void *));
322 		struct vnode vnode __aligned(sizeof(void *));
323 	};
324 	struct fileobj *fileobj;
325 	struct linux_file *filp;
326 	struct vnode *vp;
327 	int error;
328 
329 	fileobj = kzalloc(sizeof(*fileobj), GFP_KERNEL);
330 	if (fileobj == NULL) {
331 		error = -ENOMEM;
332 		goto err_0;
333 	}
334 	filp = &fileobj->file;
335 	vp = &fileobj->vnode;
336 
337 	filp->f_count = 1;
338 	filp->f_vnode = vp;
339 	filp->f_shmem = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
340 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
341 	if (filp->f_shmem == NULL) {
342 		error = -ENOMEM;
343 		goto err_1;
344 	}
345 	return (filp);
346 err_1:
347 	kfree(filp);
348 err_0:
349 	return (ERR_PTR(error));
350 }
351 
352 static vm_ooffset_t
353 linux_invalidate_mapping_pages_sub(vm_object_t obj, vm_pindex_t start,
354     vm_pindex_t end, int flags)
355 {
356 	int start_count, end_count;
357 
358 	VM_OBJECT_WLOCK(obj);
359 	start_count = obj->resident_page_count;
360 	vm_object_page_remove(obj, start, end, flags);
361 	end_count = obj->resident_page_count;
362 	VM_OBJECT_WUNLOCK(obj);
363 	return (start_count - end_count);
364 }
365 
366 unsigned long
367 linux_invalidate_mapping_pages(vm_object_t obj, pgoff_t start, pgoff_t end)
368 {
369 
370 	return (linux_invalidate_mapping_pages_sub(obj, start, end, OBJPR_CLEANONLY));
371 }
372 
373 void
374 linux_shmem_truncate_range(vm_object_t obj, loff_t lstart, loff_t lend)
375 {
376 	vm_pindex_t start = OFF_TO_IDX(lstart + PAGE_SIZE - 1);
377 	vm_pindex_t end = OFF_TO_IDX(lend + 1);
378 
379 	(void) linux_invalidate_mapping_pages_sub(obj, start, end, 0);
380 }
381