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/sx.h>
48
49#include <vm/vm.h>
50#include <vm/vm_param.h>
51#include <vm/vm_object.h>
52#include <vm/vm_page.h>
53#include <vm/vm_pager.h>
54#include <vm/uma.h>
55
56static void dev_pager_init(void);
57static vm_object_t dev_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
58    vm_ooffset_t, struct ucred *);
59static void dev_pager_dealloc(vm_object_t);
60static int dev_pager_getpages(vm_object_t, vm_page_t *, int, int);
61static void dev_pager_putpages(vm_object_t, vm_page_t *, int,
62		boolean_t, int *);
63static boolean_t dev_pager_haspage(vm_object_t, vm_pindex_t, int *,
64		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()
103{
104	TAILQ_INIT(&dev_pager_object_list);
105	mtx_init(&dev_pager_mtx, "dev_pager list", NULL, MTX_DEF);
106}
107
108vm_object_t
109cdev_pager_lookup(void *handle)
110{
111	vm_object_t object;
112
113	mtx_lock(&dev_pager_mtx);
114	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
115	mtx_unlock(&dev_pager_mtx);
116	return (object);
117}
118
119vm_object_t
120cdev_pager_allocate(void *handle, enum obj_type tp, struct cdev_pager_ops *ops,
121    vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
122{
123	vm_object_t object, object1;
124	vm_pindex_t pindex;
125	u_short color;
126
127	if (tp != OBJT_DEVICE && tp != OBJT_MGTDEVICE)
128		return (NULL);
129
130	/*
131	 * Offset should be page aligned.
132	 */
133	if (foff & PAGE_MASK)
134		return (NULL);
135
136	size = round_page(size);
137	pindex = OFF_TO_IDX(foff + size);
138
139	if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
140		return (NULL);
141	mtx_lock(&dev_pager_mtx);
142
143	/*
144	 * Look up pager, creating as necessary.
145	 */
146	object1 = NULL;
147	object = vm_pager_object_lookup(&dev_pager_object_list, handle);
148	if (object == NULL) {
149		/*
150		 * Allocate object and associate it with the pager.  Initialize
151		 * the object's pg_color based upon the physical address of the
152		 * device's memory.
153		 */
154		mtx_unlock(&dev_pager_mtx);
155		object1 = vm_object_allocate(tp, pindex);
156		object1->flags |= OBJ_COLORED;
157		object1->pg_color = color;
158		object1->handle = handle;
159		object1->un_pager.devp.ops = ops;
160		TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
161		mtx_lock(&dev_pager_mtx);
162		object = vm_pager_object_lookup(&dev_pager_object_list, handle);
163		if (object != NULL) {
164			/*
165			 * We raced with other thread while allocating object.
166			 */
167			if (pindex > object->size)
168				object->size = pindex;
169		} else {
170			object = object1;
171			object1 = NULL;
172			object->handle = handle;
173			TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
174			    pager_object_list);
175			KASSERT(object->type == tp,
176		("Inconsistent device pager type %p %d", object, tp));
177		}
178	} else {
179		if (pindex > object->size)
180			object->size = pindex;
181	}
182	mtx_unlock(&dev_pager_mtx);
183	if (object1 != NULL) {
184		object1->handle = object1;
185		mtx_lock(&dev_pager_mtx);
186		TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
187		    pager_object_list);
188		mtx_unlock(&dev_pager_mtx);
189		vm_object_deallocate(object1);
190	}
191	return (object);
192}
193
194static vm_object_t
195dev_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
196    vm_ooffset_t foff, struct ucred *cred)
197{
198
199	return (cdev_pager_allocate(handle, OBJT_DEVICE, &old_dev_pager_ops,
200	    size, prot, foff, cred));
201}
202
203void
204cdev_pager_free_page(vm_object_t object, vm_page_t m)
205{
206
207	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
208	if (object->type == OBJT_MGTDEVICE) {
209		KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m));
210		pmap_remove_all(m);
211		vm_page_lock(m);
212		vm_page_remove(m);
213		vm_page_unlock(m);
214	} else if (object->type == OBJT_DEVICE)
215		dev_pager_free_page(object, m);
216}
217
218static void
219dev_pager_free_page(vm_object_t object, vm_page_t m)
220{
221
222	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
223	KASSERT((object->type == OBJT_DEVICE &&
224	    (m->oflags & VPO_UNMANAGED) != 0),
225	    ("Managed device or page obj %p m %p", object, m));
226	TAILQ_REMOVE(&object->un_pager.devp.devp_pglist, m, pageq);
227	vm_page_putfake(m);
228}
229
230static void
231dev_pager_dealloc(object)
232	vm_object_t object;
233{
234	vm_page_t m;
235
236	VM_OBJECT_UNLOCK(object);
237	object->un_pager.devp.ops->cdev_pg_dtor(object->handle);
238
239	mtx_lock(&dev_pager_mtx);
240	TAILQ_REMOVE(&dev_pager_object_list, object, pager_object_list);
241	mtx_unlock(&dev_pager_mtx);
242	VM_OBJECT_LOCK(object);
243
244	if (object->type == OBJT_DEVICE) {
245		/*
246		 * Free up our fake pages.
247		 */
248		while ((m = TAILQ_FIRST(&object->un_pager.devp.devp_pglist))
249		    != NULL)
250			dev_pager_free_page(object, m);
251	}
252}
253
254static int
255dev_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int reqpage)
256{
257	int error, i;
258
259	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
260	error = object->un_pager.devp.ops->cdev_pg_fault(object,
261	    IDX_TO_OFF(ma[reqpage]->pindex), PROT_READ, &ma[reqpage]);
262
263	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
264
265	for (i = 0; i < count; i++) {
266		if (i != reqpage) {
267			vm_page_lock(ma[i]);
268			vm_page_free(ma[i]);
269			vm_page_unlock(ma[i]);
270		}
271	}
272
273	if (error == VM_PAGER_OK) {
274		KASSERT((object->type == OBJT_DEVICE &&
275		     (ma[reqpage]->oflags & VPO_UNMANAGED) != 0) ||
276		    (object->type == OBJT_MGTDEVICE &&
277		     (ma[reqpage]->oflags & VPO_UNMANAGED) == 0),
278		    ("Wrong page type %p %p", ma[reqpage], object));
279		if (object->type == OBJT_DEVICE) {
280			TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist,
281			    ma[reqpage], pageq);
282		}
283	}
284
285	return (error);
286}
287
288static int
289old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot,
290    vm_page_t *mres)
291{
292	vm_pindex_t pidx;
293	vm_paddr_t paddr;
294	vm_page_t m_paddr, page;
295	struct cdev *dev;
296	struct cdevsw *csw;
297	struct file *fpop;
298	struct thread *td;
299	vm_memattr_t memattr;
300	int ref, ret;
301
302	pidx = OFF_TO_IDX(offset);
303	memattr = object->memattr;
304
305	VM_OBJECT_UNLOCK(object);
306
307	dev = object->handle;
308	csw = dev_refthread(dev, &ref);
309	if (csw == NULL) {
310		VM_OBJECT_LOCK(object);
311		return (VM_PAGER_FAIL);
312	}
313	td = curthread;
314	fpop = td->td_fpop;
315	td->td_fpop = NULL;
316	ret = csw->d_mmap(dev, offset, &paddr, prot, &memattr);
317	td->td_fpop = fpop;
318	dev_relthread(dev, ref);
319	if (ret != 0) {
320		printf(
321	    "WARNING: dev_pager_getpage: map function returns error %d", ret);
322		VM_OBJECT_LOCK(object);
323		return (VM_PAGER_FAIL);
324	}
325
326	/* If "paddr" is a real page, perform a sanity check on "memattr". */
327	if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL &&
328	    pmap_page_get_memattr(m_paddr) != memattr) {
329		memattr = pmap_page_get_memattr(m_paddr);
330		printf(
331	    "WARNING: A device driver has set \"memattr\" inconsistently.\n");
332	}
333	if (((*mres)->flags & PG_FICTITIOUS) != 0) {
334		/*
335		 * If the passed in result page is a fake page, update it with
336		 * the new physical address.
337		 */
338		page = *mres;
339		VM_OBJECT_LOCK(object);
340		vm_page_updatefake(page, paddr, memattr);
341	} else {
342		/*
343		 * Replace the passed in reqpage page with our own fake page and
344		 * free up the all of the original pages.
345		 */
346		page = vm_page_getfake(paddr, memattr);
347		VM_OBJECT_LOCK(object);
348		vm_page_lock(*mres);
349		vm_page_free(*mres);
350		vm_page_unlock(*mres);
351		*mres = page;
352		vm_page_insert(page, object, pidx);
353	}
354	page->valid = VM_PAGE_BITS_ALL;
355	return (VM_PAGER_OK);
356}
357
358static void
359dev_pager_putpages(object, m, count, sync, rtvals)
360	vm_object_t object;
361	vm_page_t *m;
362	int count;
363	boolean_t sync;
364	int *rtvals;
365{
366
367	panic("dev_pager_putpage called");
368}
369
370static boolean_t
371dev_pager_haspage(object, pindex, before, after)
372	vm_object_t object;
373	vm_pindex_t pindex;
374	int *before;
375	int *after;
376{
377	if (before != NULL)
378		*before = 0;
379	if (after != NULL)
380		*after = 0;
381	return (TRUE);
382}
383
384static int
385old_dev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
386    vm_ooffset_t foff, struct ucred *cred, u_short *color)
387{
388	struct cdev *dev;
389	struct cdevsw *csw;
390	vm_memattr_t dummy;
391	vm_ooffset_t off;
392	vm_paddr_t paddr;
393	unsigned int npages;
394	int ref;
395
396	/*
397	 * Make sure this device can be mapped.
398	 */
399	dev = handle;
400	csw = dev_refthread(dev, &ref);
401	if (csw == NULL)
402		return (ENXIO);
403
404	/*
405	 * Check that the specified range of the device allows the desired
406	 * protection.
407	 *
408	 * XXX assumes VM_PROT_* == PROT_*
409	 */
410	npages = OFF_TO_IDX(size);
411	paddr = 0; /* Make paddr initialized for the case of size == 0. */
412	for (off = foff; npages--; off += PAGE_SIZE) {
413		if (csw->d_mmap(dev, off, &paddr, (int)prot, &dummy) != 0) {
414			dev_relthread(dev, ref);
415			return (EINVAL);
416		}
417	}
418
419	dev_ref(dev);
420	dev_relthread(dev, ref);
421	*color = atop(paddr) - OFF_TO_IDX(off - PAGE_SIZE);
422	return (0);
423}
424
425static void
426old_dev_pager_dtor(void *handle)
427{
428
429	dev_rel(handle);
430}
431