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("$FreeBSD$");
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,
64		boolean_t, int *);
65static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
66		int *);
67static void dev_pager_free_page(vm_object_t object, vm_page_t m);
68
69/* list of device pager objects */
70static struct pagerlst dev_pager_object_list;
71/* protect list manipulation */
72static struct mtx dev_pager_mtx;
73
74struct pagerops devicepagerops = {
75	.pgo_init =	dev_pager_init,
76	.pgo_alloc =	dev_pager_alloc,
77	.pgo_dealloc =	dev_pager_dealloc,
78	.pgo_getpages =	dev_pager_getpages,
79	.pgo_putpages =	dev_pager_putpages,
80	.pgo_haspage =	dev_pager_haspage,
81};
82
83struct pagerops mgtdevicepagerops = {
84	.pgo_alloc =	dev_pager_alloc,
85	.pgo_dealloc =	dev_pager_dealloc,
86	.pgo_getpages =	dev_pager_getpages,
87	.pgo_putpages =	dev_pager_putpages,
88	.pgo_haspage =	dev_pager_haspage,
89};
90
91static int old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
92    vm_ooffset_t foff, struct ucred *cred, u_short *color);
93static void old_dev_pager_dtor(void *handle);
94static int old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset,
95    int prot, vm_page_t *mres);
96
97static struct cdev_pager_ops old_dev_pager_ops = {
98	.cdev_pg_ctor =	old_dev_pager_ctor,
99	.cdev_pg_dtor =	old_dev_pager_dtor,
100	.cdev_pg_fault = old_dev_pager_fault
101};
102
103static void
104dev_pager_init()
105{
106	TAILQ_INIT(&dev_pager_object_list);
107	mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
108}
109
110vm_object_t
111cdev_pager_lookup(void *handle)
112{
113	vm_object_t object;
114
115	mtx_lock(&dev_pager_mtx);
116	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
117	mtx_unlock(&dev_pager_mtx);
118	return (object);
119}
120
121vm_object_t
122cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops,
123    vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
124{
125	vm_object_t object, object1;
126	vm_pindex_t pindex;
127	u_short color;
128
129	if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
130		return (NULL);
131
132	/*
133	 * Offset should be page aligned.
134	 */
135	if (foff & PAGE_MASK)
136		return (NULL);
137
138	size = round_page(size);
139	pindex = OFF_TO_IDX(foff + size);
140
141	if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
142		return (NULL);
143	mtx_lock(&dev_pager_mtx);
144
145	/*
146	 * Look up pager, creating as necessary.
147	 */
148	object1 = NULL;
149	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
150	if (object == NULL) {
151		/*
152		 * Allocate object and associate it with the pager.  Initialize
153		 * the object's pg_color based upon the physical address of the
154		 * device's memory.
155		 */
156		mtx_unlock(&dev_pager_mtx);
157		object1 = vm_object_allocate(tp, pindex);
158		object1->flags |= OBJ_COLORED;
159		object1->pg_color = color;
160		object1->handle = handle;
161		object1->un_pager.devp.ops = ops;
162		object1->un_pager.devp.dev = handle;
163		TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
164		mtx_lock(&dev_pager_mtx);
165		object = vm_pager_object_lookup(&dev_pager_object_list, handle);
166		if (object != NULL) {
167			/*
168			 * We raced with other thread while allocating object.
169			 */
170			if (pindex > object->size)
171				object->size = pindex;
172		} else {
173			object = object1;
174			object1 = NULL;
175			object->handle = handle;
176			TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
177			    pager_object_list);
178			KASSERT(object->type == tp,
179		("Inconsistent device pager type %p %d", object, tp));
180		}
181	} else {
182		if (pindex > object->size)
183			object->size = pindex;
184	}
185	mtx_unlock(&dev_pager_mtx);
186	if (object1 != NULL) {
187		object1->handle = object1;
188		mtx_lock(&dev_pager_mtx);
189		TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
190		    pager_object_list);
191		mtx_unlock(&dev_pager_mtx);
192		vm_object_deallocate(object1);
193	}
194	return (object);
195}
196
197static vm_object_t
198dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
199    vm_ooffset_t foff, struct ucred *cred)
200{
201
202	return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
203	    size, prot, foff, cred));
204}
205
206void
207cdev_pager_free_page(vm_object_t object, vm_page_t m)
208{
209
210	VM_OBJECT_ASSERT_WLOCKED(object);
211	if (object->type == OBJT_MGTDEVICE) {
212		KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
213		pmap_remove_all(m);
214		vm_page_lock(m);
215		vm_page_remove(m);
216		vm_page_unlock(m);
217	} else if (object->type == OBJT_DEVICE)
218		dev_pager_free_page(object, m);
219}
220
221static void
222dev_pager_free_page(vm_object_t object, vm_page_t m)
223{
224
225	VM_OBJECT_ASSERT_WLOCKED(object);
226	KASSERT((object->type == OBJT_DEVICE &&
227	    (m->oflags & VPO_UNMANAGED) != 0),
228	    ("Managed device or page obj %p m %p", object, m));
229	TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, plinks.q);
230	vm_page_putfake(m);
231}
232
233static void
234dev_pager_dealloc(object)
235	vm_object_t object;
236{
237	vm_page_t m;
238
239	VM_OBJECT_WUNLOCK(object);
240	object->un_pager.devp.ops->cdev_pg_dtor(object->un_pager.devp.dev);
241
242	mtx_lock(&dev_pager_mtx);
243	TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
244	mtx_unlock(&dev_pager_mtx);
245	VM_OBJECT_WLOCK(object);
246
247	if (object->type == OBJT_DEVICE) {
248		/*
249		 * Free up our fake pages.
250		 */
251		while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
252		    != NULL)
253			dev_pager_free_page(object, m);
254	}
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_pindex_t pidx;
296	vm_paddr_t paddr;
297	vm_page_t m_paddr, page;
298	struct cdev *dev;
299	struct cdevsw *csw;
300	struct file *fpop;
301	struct thread *td;
302	vm_memattr_t memattr;
303	int ref, ret;
304
305	pidx = OFF_TO_IDX(offset);
306	memattr = object->memattr;
307
308	VM_OBJECT_WUNLOCK(object);
309
310	dev = object->handle;
311	csw = dev_refthread(dev, &ref);
312	if (csw == NULL) {
313		VM_OBJECT_WLOCK(object);
314		return (VM_PAGER_FAIL);
315	}
316	td = curthread;
317	fpop = td->td_fpop;
318	td->td_fpop = NULL;
319	ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
320	td->td_fpop = fpop;
321	dev_relthread(dev, ref);
322	if (ret != 0) {
323		printf(
324	    "WARNING: dev_pager_getpage: map function returns error %d", ret);
325		VM_OBJECT_WLOCK(object);
326		return (VM_PAGER_FAIL);
327	}
328
329	/* If "paddr" is a real page, perform a sanity check on "memattr". */
330	if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
331	    pmap_page_get_memattr(m_paddr) != memattr) {
332		memattr = pmap_page_get_memattr(m_paddr);
333		printf(
334	    "WARNING: A device driver has set \"memattr\" inconsistently.\n");
335	}
336	if (((*mres)->flags & PG_FICTITIOUS) != 0) {
337		/*
338		 * If the passed in result page is a fake page, update it with
339		 * the new physical address.
340		 */
341		page = *mres;
342		VM_OBJECT_WLOCK(object);
343		vm_page_updatefake(page, paddr, memattr);
344	} else {
345		/*
346		 * Replace the passed in reqpage page with our own fake page and
347		 * free up the all of the original pages.
348		 */
349		page = vm_page_getfake(paddr, memattr);
350		VM_OBJECT_WLOCK(object);
351		if (vm_page_replace(page, object, (*mres)->pindex) != *mres)
352			panic("old_dev_pager_fault: invalid page replacement");
353		vm_page_lock(*mres);
354		vm_page_free(*mres);
355		vm_page_unlock(*mres);
356		*mres = page;
357	}
358	page->valid = VM_PAGE_BITS_ALL;
359	return (VM_PAGER_OK);
360}
361
362static void
363dev_pager_putpages(object, m, count, sync, rtvals)
364	vm_object_t object;
365	vm_page_t *m;
366	int count;
367	boolean_t sync;
368	int *rtvals;
369{
370
371	panic("dev_pager_putpage called");
372}
373
374static boolean_t
375dev_pager_haspage(object, pindex, before, after)
376	vm_object_t object;
377	vm_pindex_t pindex;
378	int *before;
379	int *after;
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	for (off = foff; npages--; off += PAGE_SIZE) {
416		if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
417			dev_relthread(dev, ref);
418			return (EINVAL);
419		}
420	}
421
422	dev_ref(dev);
423	dev_relthread(dev, ref);
424	*color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
425	return (0);
426}
427
428static void
429old_dev_pager_dtor(void *handle)
430{
431
432	dev_rel(handle);
433}
434