xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 6683132d54bd6d589889e43dabdc53d35e38a028)
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 #ifdef __GFP_NOTWIRED
97 		if ((flags & __GFP_NOTWIRED) != 0)
98 			req &= ~VM_ALLOC_WIRED;
99 #endif
100 		if ((flags & M_ZERO) != 0)
101 			req |= VM_ALLOC_ZERO;
102 		if (order == 0 && (flags & GFP_DMA32) == 0) {
103 			page = vm_page_alloc(NULL, 0, req);
104 			if (page == NULL)
105 				return (NULL);
106 		} else {
107 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
108 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
109 		retry:
110 			page = vm_page_alloc_contig(NULL, 0, req,
111 			    npages, 0, pmax, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
112 
113 			if (page == NULL) {
114 				if (flags & M_WAITOK) {
115 					if (!vm_page_reclaim_contig(req,
116 					    npages, 0, pmax, PAGE_SIZE, 0)) {
117 						vm_wait(NULL);
118 					}
119 					flags &= ~M_WAITOK;
120 					goto retry;
121 				}
122 				return (NULL);
123 			}
124 		}
125 		if (flags & M_ZERO) {
126 			unsigned long x;
127 
128 			for (x = 0; x != npages; x++) {
129 				vm_page_t pgo = page + x;
130 
131 				if ((pgo->flags & PG_ZERO) == 0)
132 					pmap_zero_page(pgo);
133 			}
134 		}
135 	} else {
136 		vm_offset_t vaddr;
137 
138 		vaddr = linux_alloc_kmem(flags, order);
139 		if (vaddr == 0)
140 			return (NULL);
141 
142 		page = PHYS_TO_VM_PAGE(vtophys((void *)vaddr));
143 
144 		KASSERT(vaddr == (vm_offset_t)page_address(page),
145 		    ("Page address mismatch"));
146 	}
147 
148 	return (page);
149 }
150 
151 void
152 linux_free_pages(vm_page_t page, unsigned int order)
153 {
154 	if (PMAP_HAS_DMAP) {
155 		unsigned long npages = 1UL << order;
156 		unsigned long x;
157 
158 		for (x = 0; x != npages; x++) {
159 			vm_page_t pgo = page + x;
160 
161 			vm_page_lock(pgo);
162 			if (vm_page_unwire_noq(pgo))
163 				vm_page_free(pgo);
164 			vm_page_unlock(pgo);
165 		}
166 	} else {
167 		vm_offset_t vaddr;
168 
169 		vaddr = (vm_offset_t)page_address(page);
170 
171 		linux_free_kmem(vaddr, order);
172 	}
173 }
174 
175 vm_offset_t
176 linux_alloc_kmem(gfp_t flags, unsigned int order)
177 {
178 	size_t size = ((size_t)PAGE_SIZE) << order;
179 	vm_offset_t addr;
180 
181 	if ((flags & GFP_DMA32) == 0) {
182 		addr = kmem_malloc(size, flags & GFP_NATIVE_MASK);
183 	} else {
184 		addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
185 		    BUS_SPACE_MAXADDR_32BIT, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
186 	}
187 	return (addr);
188 }
189 
190 void
191 linux_free_kmem(vm_offset_t addr, unsigned int order)
192 {
193 	size_t size = ((size_t)PAGE_SIZE) << order;
194 
195 	kmem_free(addr, size);
196 }
197 
198 static int
199 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
200     int write, struct page **pages)
201 {
202 	vm_prot_t prot;
203 	size_t len;
204 	int count;
205 	int i;
206 
207 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
208 	len = ((size_t)nr_pages) << PAGE_SHIFT;
209 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
210 	if (count == -1)
211 		return (-EFAULT);
212 
213 	for (i = 0; i != nr_pages; i++) {
214 		struct page *pg = pages[i];
215 
216 		vm_page_lock(pg);
217 		vm_page_wire(pg);
218 		vm_page_unhold(pg);
219 		vm_page_unlock(pg);
220 	}
221 	return (nr_pages);
222 }
223 
224 int
225 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
226     struct page **pages)
227 {
228 	vm_map_t map;
229 	vm_page_t *mp;
230 	vm_offset_t va;
231 	vm_offset_t end;
232 	vm_prot_t prot;
233 	int count;
234 
235 	if (nr_pages == 0 || in_interrupt())
236 		return (0);
237 
238 	MPASS(pages != NULL);
239 	va = start;
240 	map = &curthread->td_proc->p_vmspace->vm_map;
241 	end = start + (((size_t)nr_pages) << PAGE_SHIFT);
242 	if (start < vm_map_min(map) || end > vm_map_max(map))
243 		return (-EINVAL);
244 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
245 	for (count = 0, mp = pages, va = start; va < end;
246 	    mp++, va += PAGE_SIZE, count++) {
247 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
248 		if (*mp == NULL)
249 			break;
250 
251 		vm_page_lock(*mp);
252 		vm_page_wire(*mp);
253 		vm_page_unhold(*mp);
254 		vm_page_unlock(*mp);
255 
256 		if ((prot & VM_PROT_WRITE) != 0 &&
257 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
258 			/*
259 			 * Explicitly dirty the physical page.  Otherwise, the
260 			 * caller's changes may go unnoticed because they are
261 			 * performed through an unmanaged mapping or by a DMA
262 			 * operation.
263 			 *
264 			 * The object lock is not held here.
265 			 * See vm_page_clear_dirty_mask().
266 			 */
267 			vm_page_dirty(*mp);
268 		}
269 	}
270 	return (count);
271 }
272 
273 long
274 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
275     unsigned long start, unsigned long nr_pages, int gup_flags,
276     struct page **pages, struct vm_area_struct **vmas)
277 {
278 	vm_map_t map;
279 
280 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
281 	return (linux_get_user_pages_internal(map, start, nr_pages,
282 	    !!(gup_flags & FOLL_WRITE), pages));
283 }
284 
285 long
286 get_user_pages(unsigned long start, unsigned long nr_pages, int gup_flags,
287     struct page **pages, struct vm_area_struct **vmas)
288 {
289 	vm_map_t map;
290 
291 	map = &curthread->td_proc->p_vmspace->vm_map;
292 	return (linux_get_user_pages_internal(map, start, nr_pages,
293 	    !!(gup_flags & FOLL_WRITE), pages));
294 }
295 
296 int
297 is_vmalloc_addr(const void *addr)
298 {
299 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
300 }
301 
302 struct page *
303 linux_shmem_read_mapping_page_gfp(vm_object_t obj, int pindex, gfp_t gfp)
304 {
305 	vm_page_t page;
306 	int rv;
307 
308 	if ((gfp & GFP_NOWAIT) != 0)
309 		panic("GFP_NOWAIT is unimplemented");
310 
311 	VM_OBJECT_WLOCK(obj);
312 	page = vm_page_grab(obj, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
313 	    VM_ALLOC_WIRED);
314 	if (page->valid != VM_PAGE_BITS_ALL) {
315 		vm_page_xbusy(page);
316 		if (vm_pager_has_page(obj, pindex, NULL, NULL)) {
317 			rv = vm_pager_get_pages(obj, &page, 1, NULL, NULL);
318 			if (rv != VM_PAGER_OK) {
319 				vm_page_lock(page);
320 				vm_page_unwire_noq(page);
321 				vm_page_free(page);
322 				vm_page_unlock(page);
323 				VM_OBJECT_WUNLOCK(obj);
324 				return (ERR_PTR(-EINVAL));
325 			}
326 			MPASS(page->valid == VM_PAGE_BITS_ALL);
327 		} else {
328 			pmap_zero_page(page);
329 			page->valid = VM_PAGE_BITS_ALL;
330 			page->dirty = 0;
331 		}
332 		vm_page_xunbusy(page);
333 	}
334 	VM_OBJECT_WUNLOCK(obj);
335 	return (page);
336 }
337 
338 struct linux_file *
339 linux_shmem_file_setup(const char *name, loff_t size, unsigned long flags)
340 {
341 	struct fileobj {
342 		struct linux_file file __aligned(sizeof(void *));
343 		struct vnode vnode __aligned(sizeof(void *));
344 	};
345 	struct fileobj *fileobj;
346 	struct linux_file *filp;
347 	struct vnode *vp;
348 	int error;
349 
350 	fileobj = kzalloc(sizeof(*fileobj), GFP_KERNEL);
351 	if (fileobj == NULL) {
352 		error = -ENOMEM;
353 		goto err_0;
354 	}
355 	filp = &fileobj->file;
356 	vp = &fileobj->vnode;
357 
358 	filp->f_count = 1;
359 	filp->f_vnode = vp;
360 	filp->f_shmem = vm_pager_allocate(OBJT_DEFAULT, NULL, size,
361 	    VM_PROT_READ | VM_PROT_WRITE, 0, curthread->td_ucred);
362 	if (filp->f_shmem == NULL) {
363 		error = -ENOMEM;
364 		goto err_1;
365 	}
366 	return (filp);
367 err_1:
368 	kfree(filp);
369 err_0:
370 	return (ERR_PTR(error));
371 }
372 
373 static vm_ooffset_t
374 linux_invalidate_mapping_pages_sub(vm_object_t obj, vm_pindex_t start,
375     vm_pindex_t end, int flags)
376 {
377 	int start_count, end_count;
378 
379 	VM_OBJECT_WLOCK(obj);
380 	start_count = obj->resident_page_count;
381 	vm_object_page_remove(obj, start, end, flags);
382 	end_count = obj->resident_page_count;
383 	VM_OBJECT_WUNLOCK(obj);
384 	return (start_count - end_count);
385 }
386 
387 unsigned long
388 linux_invalidate_mapping_pages(vm_object_t obj, pgoff_t start, pgoff_t end)
389 {
390 
391 	return (linux_invalidate_mapping_pages_sub(obj, start, end, OBJPR_CLEANONLY));
392 }
393 
394 void
395 linux_shmem_truncate_range(vm_object_t obj, loff_t lstart, loff_t lend)
396 {
397 	vm_pindex_t start = OFF_TO_IDX(lstart + PAGE_SIZE - 1);
398 	vm_pindex_t end = OFF_TO_IDX(lend + 1);
399 
400 	(void) linux_invalidate_mapping_pages_sub(obj, start, end, 0);
401 }
402