1/*-
2 * Copyright (c) 1990 University of Utah.
3 * Copyright (c) 1991, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	@(#)device_pager.c	8.1 (Berkeley) 6/11/93
35 */
36
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: stable/10/sys/vm/device_pager.c 320439 2017-06-28 06:13:58Z alc $");
39
40#include <sys/param.h>
41#include <sys/systm.h>
42#include <sys/conf.h>
43#include <sys/lock.h>
44#include <sys/proc.h>
45#include <sys/mutex.h>
46#include <sys/mman.h>
47#include <sys/rwlock.h>
48#include <sys/sx.h>
49
50#include <vm/vm.h>
51#include <vm/vm_param.h>
52#include <vm/vm_object.h>
53#include <vm/vm_page.h>
54#include <vm/vm_pager.h>
55#include <vm/vm_phys.h>
56#include <vm/uma.h>
57
58static void dev_pager_init(void);
59static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
60    vm_ooffset_t, struct ucred *);
61static void dev_pager_dealloc(vm_object_t);
62static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
63static void dev_pager_putpages(vm_object_t, vm_page_t *, int, int, int *);
64static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *, int *);
65static void dev_pager_free_page(vm_object_t object, vm_page_t m);
66
67/* list of device pager objects */
68static struct pagerlst dev_pager_object_list;
69/* protect list manipulation */
70static struct mtx dev_pager_mtx;
71
72struct pagerops devicepagerops = {
73	.pgo_init =	dev_pager_init,
74	.pgo_alloc =	dev_pager_alloc,
75	.pgo_dealloc =	dev_pager_dealloc,
76	.pgo_getpages =	dev_pager_getpages,
77	.pgo_putpages =	dev_pager_putpages,
78	.pgo_haspage =	dev_pager_haspage,
79};
80
81struct pagerops mgtdevicepagerops = {
82	.pgo_alloc =	dev_pager_alloc,
83	.pgo_dealloc =	dev_pager_dealloc,
84	.pgo_getpages =	dev_pager_getpages,
85	.pgo_putpages =	dev_pager_putpages,
86	.pgo_haspage =	dev_pager_haspage,
87};
88
89static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
90    vm_ooffset_t foff, struct ucred *cred, u_short *color);
91static void old_dev_pager_dtor(void *handle);
92static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
93    int prot, vm_page_t *mres);
94
95static struct cdev_pager_ops old_dev_pager_ops = {
96	.cdev_pg_ctor =	old_dev_pager_ctor,
97	.cdev_pg_dtor =	old_dev_pager_dtor,
98	.cdev_pg_fault = old_dev_pager_fault
99};
100
101static void
102dev_pager_init(void)
103{
104
105	TAILQ_INIT(&dev_pager_object_list);
106	mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
107}
108
109vm_object_t
110cdev_pager_lookup(void *handle)
111{
112	vm_object_t object;
113
114	mtx_lock(&dev_pager_mtx);
115	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
116	mtx_unlock(&dev_pager_mtx);
117	return (object);
118}
119
120vm_object_t
121cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops,
122    vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
123{
124	vm_object_t object, object1;
125	vm_pindex_t pindex;
126	u_short color;
127
128	if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
129		return (NULL);
130
131	/*
132	 * Offset should be page aligned.
133	 */
134	if (foff & PAGE_MASK)
135		return (NULL);
136
137	size = round_page(size);
138	pindex = OFF_TO_IDX(foff + size);
139
140	if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
141		return (NULL);
142	mtx_lock(&dev_pager_mtx);
143
144	/*
145	 * Look up pager, creating as necessary.
146	 */
147	object1 = NULL;
148	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
149	if (object == NULL) {
150		/*
151		 * Allocate object and associate it with the pager.  Initialize
152		 * the object's pg_color based upon the physical address of the
153		 * device's memory.
154		 */
155		mtx_unlock(&dev_pager_mtx);
156		object1 = vm_object_allocate(tp, pindex);
157		object1->flags |= OBJ_COLORED;
158		object1->pg_color = color;
159		object1->handle = handle;
160		object1->un_pager.devp.ops = ops;
161		object1->un_pager.devp.dev = handle;
162		TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
163		mtx_lock(&dev_pager_mtx);
164		object = vm_pager_object_lookup(&dev_pager_object_list, handle);
165		if (object != NULL) {
166			/*
167			 * We raced with other thread while allocating object.
168			 */
169			if (pindex > object->size)
170				object->size = pindex;
171		} else {
172			object = object1;
173			object1 = NULL;
174			object->handle = handle;
175			TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
176			    pager_object_list);
177			KASSERT(object->type == tp,
178		("Inconsistent device pager type %p %d", object, tp));
179		}
180	} else {
181		if (pindex > object->size)
182			object->size = pindex;
183	}
184	mtx_unlock(&dev_pager_mtx);
185	if (object1 != NULL) {
186		object1->handle = object1;
187		mtx_lock(&dev_pager_mtx);
188		TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
189		    pager_object_list);
190		mtx_unlock(&dev_pager_mtx);
191		vm_object_deallocate(object1);
192	}
193	return (object);
194}
195
196static vm_object_t
197dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
198    vm_ooffset_t foff, struct ucred *cred)
199{
200
201	return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
202	    size, prot, foff, cred));
203}
204
205void
206cdev_pager_free_page(vm_object_t object, vm_page_t m)
207{
208
209	VM_OBJECT_ASSERT_WLOCKED(object);
210	if (object->type == OBJT_MGTDEVICE) {
211		KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
212		pmap_remove_all(m);
213		vm_page_lock(m);
214		vm_page_remove(m);
215		vm_page_unlock(m);
216	} else if (object->type == OBJT_DEVICE)
217		dev_pager_free_page(object, m);
218}
219
220static void
221dev_pager_free_page(vm_object_t object, vm_page_t m)
222{
223
224	VM_OBJECT_ASSERT_WLOCKED(object);
225	KASSERT((object->type == OBJT_DEVICE &&
226	    (m->oflags & VPO_UNMANAGED) != 0),
227	    ("Managed device or page obj %p m %p", object, m));
228	TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q);
229	vm_page_putfake(m);
230}
231
232static void
233dev_pager_dealloc(vm_object_t object)
234{
235	vm_page_t m;
236
237	VM_OBJECT_WUNLOCK(object);
238	object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev);
239
240	mtx_lock(&dev_pager_mtx);
241	TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
242	mtx_unlock(&dev_pager_mtx);
243	VM_OBJECT_WLOCK(object);
244
245	if (object->type == OBJT_DEVICE) {
246		/*
247		 * Free up our fake pages.
248		 */
249		while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
250		    != NULL)
251			dev_pager_free_page(object, m);
252	}
253	object->handle = NULL;
254	object->type = OBJT_DEAD;
255}
256
257static int
258dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage)
259{
260	int error, i;
261
262	VM_OBJECT_ASSERT_WLOCKED(object);
263	error = object->un_pager.devp.ops->cdev_pg_fault(object,
264	    IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]);
265
266	VM_OBJECT_ASSERT_WLOCKED(object);
267
268	for (i = 0; i < count; i++) {
269		if (i != reqpage) {
270			vm_page_lock(ma[i]);
271			vm_page_free(ma[i]);
272			vm_page_unlock(ma[i]);
273		}
274	}
275
276	if (error == VM_PAGER_OK) {
277		KASSERT((object->type == OBJT_DEVICE &&
278		     (ma[reqpage]->oflags & VPO_UNMANAGED) != 0) ||
279		    (object->type == OBJT_MGTDEVICE &&
280		     (ma[reqpage]->oflags & VPO_UNMANAGED) == 0),
281		    ("Wrong page type %p %p", ma[reqpage], object));
282		if (object->type == OBJT_DEVICE) {
283			TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
284			    ma[reqpage], plinks.q);
285		}
286	}
287
288	return (error);
289}
290
291static int
292old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
293    vm_page_t *mres)
294{
295	vm_paddr_t paddr;
296	vm_page_t m_paddr, page;
297	struct cdev *dev;
298	struct cdevsw *csw;
299	struct file *fpop;
300	struct thread *td;
301	vm_memattr_t memattr, memattr1;
302	int ref, ret;
303
304	memattr = object->memattr;
305
306	VM_OBJECT_WUNLOCK(object);
307
308	dev = object->handle;
309	csw = dev_refthread(dev, &ref);
310	if (csw == NULL) {
311		VM_OBJECT_WLOCK(object);
312		return (VM_PAGER_FAIL);
313	}
314	td = curthread;
315	fpop = td->td_fpop;
316	td->td_fpop = NULL;
317	ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
318	td->td_fpop = fpop;
319	dev_relthread(dev, ref);
320	if (ret != 0) {
321		printf(
322	    "WARNING: dev_pager_getpage: map function returns error %d", ret);
323		VM_OBJECT_WLOCK(object);
324		return (VM_PAGER_FAIL);
325	}
326
327	/* If "paddr" is a real page, perform a sanity check on "memattr". */
328	if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
329	    (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) {
330		/*
331		 * For the /dev/mem d_mmap routine to return the
332		 * correct memattr, pmap_page_get_memattr() needs to
333		 * be called, which we do there.
334		 */
335		if ((csw->d_flags & D_MEM) == 0) {
336			printf("WARNING: Device driver %s has set "
337			    "\"memattr\" inconsistently (drv %u pmap %u).\n",
338			    csw->d_name, memattr, memattr1);
339		}
340		memattr = memattr1;
341	}
342	if (((*mres)->flags & PG_FICTITIOUS) != 0) {
343		/*
344		 * If the passed in result page is a fake page, update it with
345		 * the new physical address.
346		 */
347		page = *mres;
348		VM_OBJECT_WLOCK(object);
349		vm_page_updatefake(page, paddr, memattr);
350	} else {
351		/*
352		 * Replace the passed in reqpage page with our own fake page and
353		 * free up the all of the original pages.
354		 */
355		page = vm_page_getfake(paddr, memattr);
356		VM_OBJECT_WLOCK(object);
357		if (vm_page_replace(page, object, (*mres)->pindex) != *mres)
358			panic("old_dev_pager_fault: invalid page replacement");
359		vm_page_lock(*mres);
360		vm_page_free(*mres);
361		vm_page_unlock(*mres);
362		*mres = page;
363	}
364	page->valid = VM_PAGE_BITS_ALL;
365	return (VM_PAGER_OK);
366}
367
368static void
369dev_pager_putpages(vm_object_t object, vm_page_t *m, int count, int flags,
370    int *rtvals)
371{
372
373	panic("dev_pager_putpage called");
374}
375
376static boolean_t
377dev_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
378    int *after)
379{
380
381	if (before != NULL)
382		*before = 0;
383	if (after != NULL)
384		*after = 0;
385	return (TRUE);
386}
387
388static int
389old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
390    vm_ooffset_t foff, struct ucred *cred, u_short *color)
391{
392	struct cdev *dev;
393	struct cdevsw *csw;
394	vm_memattr_t dummy;
395	vm_ooffset_t off;
396	vm_paddr_t paddr;
397	unsigned int npages;
398	int ref;
399
400	/*
401	 * Make sure this device can be mapped.
402	 */
403	dev = handle;
404	csw = dev_refthread(dev, &ref);
405	if (csw == NULL)
406		return (ENXIO);
407
408	/*
409	 * Check that the specified range of the device allows the desired
410	 * protection.
411	 *
412	 * XXX assumes VM_PROT_* == PROT_*
413	 */
414	npages = OFF_TO_IDX(size);
415	paddr = 0; /* Make paddr initialized for the case of size == 0. */
416	for (off = foff; npages--; off += PAGE_SIZE) {
417		if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
418			dev_relthread(dev, ref);
419			return (EINVAL);
420		}
421	}
422
423	dev_ref(dev);
424	dev_relthread(dev, ref);
425	*color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
426	return (0);
427}
428
429static void
430old_dev_pager_dtor(void *handle)
431{
432
433	dev_rel(handle);
434}
435