xref: /freebsd/sys/compat/linuxkpi/common/src/linux_page.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
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 #include <linux/shmem_fs.h>
66 
67 void
68 si_meminfo(struct sysinfo *si)
69 {
70 	si->totalram = physmem;
71 	si->totalhigh = 0;
72 	si->mem_unit = PAGE_SIZE;
73 }
74 
75 void *
76 linux_page_address(struct page *page)
77 {
78 
79 	if (page->object != kernel_object) {
80 		return (PMAP_HAS_DMAP ?
81 		    ((void *)(uintptr_t)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(page))) :
82 		    NULL);
83 	}
84 	return ((void *)(uintptr_t)(VM_MIN_KERNEL_ADDRESS +
85 	    IDX_TO_OFF(page->pindex)));
86 }
87 
88 vm_page_t
89 linux_alloc_pages(gfp_t flags, unsigned int order)
90 {
91 	vm_page_t page;
92 
93 	if (PMAP_HAS_DMAP) {
94 		unsigned long npages = 1UL << order;
95 		int req = VM_ALLOC_WIRED;
96 
97 		if ((flags & M_ZERO) != 0)
98 			req |= VM_ALLOC_ZERO;
99 		if (order == 0 && (flags & GFP_DMA32) == 0) {
100 			page = vm_page_alloc_noobj(req);
101 			if (page == NULL)
102 				return (NULL);
103 		} else {
104 			vm_paddr_t pmax = (flags & GFP_DMA32) ?
105 			    BUS_SPACE_MAXADDR_32BIT : BUS_SPACE_MAXADDR;
106 		retry:
107 			page = vm_page_alloc_noobj_contig(req, npages, 0, pmax,
108 			    PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
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 	} else {
122 		vm_offset_t vaddr;
123 
124 		vaddr = linux_alloc_kmem(flags, order);
125 		if (vaddr == 0)
126 			return (NULL);
127 
128 		page = PHYS_TO_VM_PAGE(vtophys((void *)vaddr));
129 
130 		KASSERT(vaddr == (vm_offset_t)page_address(page),
131 		    ("Page address mismatch"));
132 	}
133 
134 	return (page);
135 }
136 
137 void
138 linux_free_pages(vm_page_t page, unsigned int order)
139 {
140 	if (PMAP_HAS_DMAP) {
141 		unsigned long npages = 1UL << order;
142 		unsigned long x;
143 
144 		for (x = 0; x != npages; x++) {
145 			vm_page_t pgo = page + x;
146 
147 			if (vm_page_unwire_noq(pgo))
148 				vm_page_free(pgo);
149 		}
150 	} else {
151 		vm_offset_t vaddr;
152 
153 		vaddr = (vm_offset_t)page_address(page);
154 
155 		linux_free_kmem(vaddr, order);
156 	}
157 }
158 
159 vm_offset_t
160 linux_alloc_kmem(gfp_t flags, unsigned int order)
161 {
162 	size_t size = ((size_t)PAGE_SIZE) << order;
163 	vm_offset_t addr;
164 
165 	if ((flags & GFP_DMA32) == 0) {
166 		addr = kmem_malloc(size, flags & GFP_NATIVE_MASK);
167 	} else {
168 		addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
169 		    BUS_SPACE_MAXADDR_32BIT, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
170 	}
171 	return (addr);
172 }
173 
174 void
175 linux_free_kmem(vm_offset_t addr, unsigned int order)
176 {
177 	size_t size = ((size_t)PAGE_SIZE) << order;
178 
179 	kmem_free(addr, size);
180 }
181 
182 static int
183 linux_get_user_pages_internal(vm_map_t map, unsigned long start, int nr_pages,
184     int write, struct page **pages)
185 {
186 	vm_prot_t prot;
187 	size_t len;
188 	int count;
189 
190 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
191 	len = ptoa((vm_offset_t)nr_pages);
192 	count = vm_fault_quick_hold_pages(map, start, len, prot, pages, nr_pages);
193 	return (count == -1 ? -EFAULT : nr_pages);
194 }
195 
196 int
197 __get_user_pages_fast(unsigned long start, int nr_pages, int write,
198     struct page **pages)
199 {
200 	vm_map_t map;
201 	vm_page_t *mp;
202 	vm_offset_t va;
203 	vm_offset_t end;
204 	vm_prot_t prot;
205 	int count;
206 
207 	if (nr_pages == 0 || in_interrupt())
208 		return (0);
209 
210 	MPASS(pages != NULL);
211 	map = &curthread->td_proc->p_vmspace->vm_map;
212 	end = start + ptoa((vm_offset_t)nr_pages);
213 	if (!vm_map_range_valid(map, start, end))
214 		return (-EINVAL);
215 	prot = write ? (VM_PROT_READ | VM_PROT_WRITE) : VM_PROT_READ;
216 	for (count = 0, mp = pages, va = start; va < end;
217 	    mp++, va += PAGE_SIZE, count++) {
218 		*mp = pmap_extract_and_hold(map->pmap, va, prot);
219 		if (*mp == NULL)
220 			break;
221 
222 		if ((prot & VM_PROT_WRITE) != 0 &&
223 		    (*mp)->dirty != VM_PAGE_BITS_ALL) {
224 			/*
225 			 * Explicitly dirty the physical page.  Otherwise, the
226 			 * caller's changes may go unnoticed because they are
227 			 * performed through an unmanaged mapping or by a DMA
228 			 * operation.
229 			 *
230 			 * The object lock is not held here.
231 			 * See vm_page_clear_dirty_mask().
232 			 */
233 			vm_page_dirty(*mp);
234 		}
235 	}
236 	return (count);
237 }
238 
239 long
240 get_user_pages_remote(struct task_struct *task, struct mm_struct *mm,
241     unsigned long start, unsigned long nr_pages, int gup_flags,
242     struct page **pages, struct vm_area_struct **vmas)
243 {
244 	vm_map_t map;
245 
246 	map = &task->task_thread->td_proc->p_vmspace->vm_map;
247 	return (linux_get_user_pages_internal(map, start, nr_pages,
248 	    !!(gup_flags & FOLL_WRITE), pages));
249 }
250 
251 long
252 get_user_pages(unsigned long start, unsigned long nr_pages, int gup_flags,
253     struct page **pages, struct vm_area_struct **vmas)
254 {
255 	vm_map_t map;
256 
257 	map = &curthread->td_proc->p_vmspace->vm_map;
258 	return (linux_get_user_pages_internal(map, start, nr_pages,
259 	    !!(gup_flags & FOLL_WRITE), pages));
260 }
261 
262 int
263 is_vmalloc_addr(const void *addr)
264 {
265 	return (vtoslab((vm_offset_t)addr & ~UMA_SLAB_MASK) != NULL);
266 }
267 
268 vm_fault_t
269 lkpi_vmf_insert_pfn_prot_locked(struct vm_area_struct *vma, unsigned long addr,
270     unsigned long pfn, pgprot_t prot)
271 {
272 	vm_object_t vm_obj = vma->vm_obj;
273 	vm_object_t tmp_obj;
274 	vm_page_t page;
275 	vm_pindex_t pindex;
276 
277 	VM_OBJECT_ASSERT_WLOCKED(vm_obj);
278 	pindex = OFF_TO_IDX(addr - vma->vm_start);
279 	if (vma->vm_pfn_count == 0)
280 		vma->vm_pfn_first = pindex;
281 	MPASS(pindex <= OFF_TO_IDX(vma->vm_end));
282 
283 retry:
284 	page = vm_page_grab(vm_obj, pindex, VM_ALLOC_NOCREAT);
285 	if (page == NULL) {
286 		page = PHYS_TO_VM_PAGE(IDX_TO_OFF(pfn));
287 		if (!vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL))
288 			goto retry;
289 		if (page->object != NULL) {
290 			tmp_obj = page->object;
291 			vm_page_xunbusy(page);
292 			VM_OBJECT_WUNLOCK(vm_obj);
293 			VM_OBJECT_WLOCK(tmp_obj);
294 			if (page->object == tmp_obj &&
295 			    vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL)) {
296 				KASSERT(page->object == tmp_obj,
297 				    ("page has changed identity"));
298 				KASSERT((page->oflags & VPO_UNMANAGED) == 0,
299 				    ("page does not belong to shmem"));
300 				vm_pager_page_unswapped(page);
301 				if (pmap_page_is_mapped(page)) {
302 					vm_page_xunbusy(page);
303 					VM_OBJECT_WUNLOCK(tmp_obj);
304 					printf("%s: page rename failed: page "
305 					    "is mapped\n", __func__);
306 					VM_OBJECT_WLOCK(vm_obj);
307 					return (VM_FAULT_NOPAGE);
308 				}
309 				vm_page_remove(page);
310 			}
311 			VM_OBJECT_WUNLOCK(tmp_obj);
312 			VM_OBJECT_WLOCK(vm_obj);
313 			goto retry;
314 		}
315 		if (vm_page_insert(page, vm_obj, pindex)) {
316 			vm_page_xunbusy(page);
317 			return (VM_FAULT_OOM);
318 		}
319 		vm_page_valid(page);
320 	}
321 	pmap_page_set_memattr(page, pgprot2cachemode(prot));
322 	vma->vm_pfn_count++;
323 
324 	return (VM_FAULT_NOPAGE);
325 }
326 
327 /*
328  * Although FreeBSD version of unmap_mapping_range has semantics and types of
329  * parameters compatible with Linux version, the values passed in are different
330  * @obj should match to vm_private_data field of vm_area_struct returned by
331  *      mmap file operation handler, see linux_file_mmap_single() sources
332  * @holelen should match to size of area to be munmapped.
333  */
334 void
335 lkpi_unmap_mapping_range(void *obj, loff_t const holebegin __unused,
336     loff_t const holelen, int even_cows __unused)
337 {
338 	vm_object_t devobj;
339 	vm_page_t page;
340 	int i, page_count;
341 
342 	devobj = cdev_pager_lookup(obj);
343 	if (devobj != NULL) {
344 		page_count = OFF_TO_IDX(holelen);
345 
346 		VM_OBJECT_WLOCK(devobj);
347 retry:
348 		for (i = 0; i < page_count; i++) {
349 			page = vm_page_lookup(devobj, i);
350 			if (page == NULL)
351 				continue;
352 			if (!vm_page_busy_acquire(page, VM_ALLOC_WAITFAIL))
353 				goto retry;
354 			cdev_pager_free_page(devobj, page);
355 		}
356 		VM_OBJECT_WUNLOCK(devobj);
357 		vm_object_deallocate(devobj);
358 	}
359 }
360