xref: /netbsd-src/sys/dev/dtv/dtv_buffer.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /* $NetBSD: dtv_buffer.c,v 1.7 2011/08/09 01:42:24 jmcneill Exp $ */
2 
3 /*-
4  * Copyright (c) 2011 Jared D. McNeill <jmcneill@invisible.ca>
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, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by Jared D. McNeill.
18  * 4. Neither the name of The NetBSD Foundation nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: dtv_buffer.c,v 1.7 2011/08/09 01:42:24 jmcneill Exp $");
37 
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/types.h>
41 #include <sys/conf.h>
42 #include <sys/device.h>
43 #include <sys/vnode.h>
44 #include <sys/poll.h>
45 #include <sys/select.h>
46 
47 #include <dev/dtv/dtvvar.h>
48 
49 #define	BLOCK_SIZE	DTV_DEFAULT_BLOCKSIZE
50 #define	BLOCK_ALIGN(a)	(((a) + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1))
51 
52 static void
53 dtv_buffer_write(struct dtv_softc *sc, const uint8_t *buf, size_t buflen)
54 {
55 	struct dtv_stream *ds = &sc->sc_stream;
56 	struct dtv_buffer *db;
57 	struct dtv_scatter_io sio;
58 	size_t resid = buflen, avail;
59        	off_t offset = 0;
60 
61 	KASSERT(buflen == TS_PKTLEN);
62 
63 	while (resid > 0) {
64 		mutex_enter(&ds->ds_ingress_lock);
65 
66 		if (SIMPLEQ_EMPTY(&ds->ds_ingress)) {
67 			aprint_debug_dev(sc->sc_dev,
68 			    "dropping sample (%zu)\n", resid);
69 			mutex_exit(&ds->ds_ingress_lock);
70 			return;
71 		}
72 
73 		db = SIMPLEQ_FIRST(&ds->ds_ingress);
74 		mutex_exit(&ds->ds_ingress_lock);
75 
76 		avail = min(db->db_length - db->db_bytesused, resid);
77 		if (dtv_scatter_io_init(&ds->ds_data,
78 		    db->db_offset + db->db_bytesused, avail, &sio)) {
79 			dtv_scatter_io_copyin(&sio, buf + offset);
80 			db->db_bytesused += (avail - sio.sio_resid);
81 			offset += (avail - sio.sio_resid);
82 			resid -= (avail - sio.sio_resid);
83 		}
84 
85 		if (db->db_bytesused == db->db_length) {
86 			mutex_enter(&ds->ds_ingress_lock);
87 			SIMPLEQ_REMOVE_HEAD(&ds->ds_ingress, db_entries);
88 			mutex_exit(&ds->ds_ingress_lock);
89 			mutex_enter(&ds->ds_egress_lock);
90 			SIMPLEQ_INSERT_TAIL(&ds->ds_egress, db, db_entries);
91 			selnotify(&ds->ds_sel, 0, 0);
92 			cv_broadcast(&ds->ds_sample_cv);
93 			mutex_exit(&ds->ds_egress_lock);
94 		}
95 	}
96 }
97 
98 void
99 dtv_buffer_submit(void *priv, const struct dtv_payload *payload)
100 {
101 	struct dtv_softc *sc = priv;
102 	struct dtv_ts *ts = &sc->sc_ts;
103 	const uint8_t *tspkt;
104 	unsigned int npkts, i;
105 
106 	tspkt = payload->data;
107 	npkts = payload->size / TS_PKTLEN;
108 	for (i = 0; i < npkts; i++) {
109 		if (TS_HAS_SYNC(tspkt)) {
110 			if (ts->ts_pidfilter[TS_PID(tspkt)]) {
111 				dtv_buffer_write(sc, tspkt, TS_PKTLEN);
112 			}
113 			dtv_demux_write(sc, tspkt, TS_PKTLEN);
114 		}
115 		tspkt += TS_PKTLEN;
116 	}
117 }
118 
119 static struct dtv_buffer *
120 dtv_buffer_alloc(void)
121 {
122 	return kmem_alloc(sizeof(struct dtv_buffer), KM_SLEEP);
123 }
124 
125 static void
126 dtv_buffer_free(struct dtv_buffer *db)
127 {
128 	kmem_free(db, sizeof(*db));
129 }
130 
131 int
132 dtv_buffer_realloc(struct dtv_softc *sc, size_t bufsize)
133 {
134 	struct dtv_stream *ds = &sc->sc_stream;
135 	unsigned int i, nbufs, oldnbufs, minnbufs;
136 	struct dtv_buffer **oldbuf;
137 	off_t offset;
138 	int error;
139 
140 	nbufs = BLOCK_ALIGN(bufsize) / BLOCK_SIZE;
141 
142 	error = dtv_scatter_buf_set_size(&ds->ds_data, bufsize);
143 	if (error)
144 		return error;
145 
146 	oldnbufs = ds->ds_nbufs;
147 	oldbuf = ds->ds_buf;
148 
149 	ds->ds_nbufs = nbufs;
150 	if (nbufs > 0) {
151 		ds->ds_buf = kmem_alloc(sizeof(struct dtv_buffer *) * nbufs,
152 		    KM_SLEEP);
153 		if (ds->ds_buf == NULL) {
154 			ds->ds_nbufs = oldnbufs;
155 			ds->ds_buf = oldbuf;
156 			return ENOMEM;
157 		}
158 	} else {
159 		ds->ds_buf = NULL;
160 	}
161 
162 	minnbufs = min(nbufs, oldnbufs);
163 	for (i = 0; i < minnbufs; i++)
164 		ds->ds_buf[i] = oldbuf[i];
165 	for (; i < nbufs; i++)
166 		ds->ds_buf[i] = dtv_buffer_alloc();
167 	for (; i < oldnbufs; i++) {
168 		dtv_buffer_free(oldbuf[i]);
169 		oldbuf[i] = NULL;
170 	}
171 	if (oldbuf != NULL)
172 		kmem_free(oldbuf, sizeof(struct dtv_buffer *) * oldnbufs);
173 
174 	offset = 0;
175 	for (i = 0; i < nbufs; i++) {
176 		ds->ds_buf[i]->db_offset = offset;
177 		ds->ds_buf[i]->db_bytesused = 0;
178 		ds->ds_buf[i]->db_length = BLOCK_SIZE;
179 		offset += BLOCK_SIZE;
180 	}
181 
182 	return 0;
183 }
184 
185 static struct dtv_buffer *
186 dtv_stream_dequeue(struct dtv_stream *ds)
187 {
188 	struct dtv_buffer *db;
189 
190 	if (!SIMPLEQ_EMPTY(&ds->ds_egress)) {
191 		db = SIMPLEQ_FIRST(&ds->ds_egress);
192 		SIMPLEQ_REMOVE_HEAD(&ds->ds_egress, db_entries);
193 		return db;
194 	}
195 
196 	return NULL;
197 }
198 
199 static void
200 dtv_stream_enqueue(struct dtv_stream *ds, struct dtv_buffer *db)
201 {
202 	db->db_bytesused = 0;
203 	SIMPLEQ_INSERT_TAIL(&ds->ds_ingress, db, db_entries);
204 }
205 
206 int
207 dtv_buffer_setup(struct dtv_softc *sc)
208 {
209 	struct dtv_stream *ds = &sc->sc_stream;
210 	unsigned int i;
211 
212 	mutex_enter(&ds->ds_ingress_lock);
213 	for (i = 0; i < ds->ds_nbufs; i++)
214 		dtv_stream_enqueue(ds, ds->ds_buf[i]);
215 	mutex_exit(&ds->ds_ingress_lock);
216 
217 	return 0;
218 }
219 
220 int
221 dtv_buffer_destroy(struct dtv_softc *sc)
222 {
223 	struct dtv_stream *ds = &sc->sc_stream;
224 
225 	mutex_enter(&ds->ds_ingress_lock);
226 	while (SIMPLEQ_FIRST(&ds->ds_ingress))
227 		SIMPLEQ_REMOVE_HEAD(&ds->ds_ingress, db_entries);
228 	mutex_exit(&ds->ds_ingress_lock);
229 	mutex_enter(&ds->ds_egress_lock);
230 	while (SIMPLEQ_FIRST(&ds->ds_egress))
231 		SIMPLEQ_REMOVE_HEAD(&ds->ds_egress, db_entries);
232 	mutex_exit(&ds->ds_egress_lock);
233 
234 	return 0;
235 }
236 
237 int
238 dtv_buffer_read(struct dtv_softc *sc, struct uio *uio, int flags)
239 {
240 	struct dtv_stream *ds = &sc->sc_stream;
241 	struct dtv_buffer *db;
242 	struct dtv_scatter_io sio;
243 	off_t offset;
244 	size_t len, bread = 0;
245 	int error;
246 
247 	while (uio->uio_resid > 0) {
248 retry:
249 		mutex_enter(&ds->ds_egress_lock);
250 		while (SIMPLEQ_EMPTY(&ds->ds_egress)) {
251 			if (flags & IO_NDELAY) {
252 				mutex_exit(&ds->ds_egress_lock);
253 				return EWOULDBLOCK;
254 			}
255 
256 			error = cv_wait_sig(&ds->ds_sample_cv,
257 			    &ds->ds_egress_lock);
258 			if (error) {
259 				mutex_exit(&ds->ds_egress_lock);
260 				return EINTR;
261 			}
262 		}
263 		db = SIMPLEQ_FIRST(&ds->ds_egress);
264 		mutex_exit(&ds->ds_egress_lock);
265 
266 		if (db->db_bytesused == 0) {
267 			mutex_enter(&ds->ds_egress_lock);
268 			db = dtv_stream_dequeue(ds);
269 			mutex_exit(&ds->ds_egress_lock);
270 			mutex_enter(&ds->ds_ingress_lock);
271 			dtv_stream_enqueue(ds, db);
272 			mutex_exit(&ds->ds_ingress_lock);
273 			ds->ds_bytesread = 0;
274 			goto retry;
275 		}
276 
277 		len = min(uio->uio_resid, db->db_bytesused - ds->ds_bytesread);
278 		offset = db->db_offset + ds->ds_bytesread;
279 
280 		if (dtv_scatter_io_init(&ds->ds_data, offset, len, &sio)) {
281 			error = dtv_scatter_io_uiomove(&sio, uio);
282 			if (error == EFAULT)
283 				return EFAULT;
284 			ds->ds_bytesread += (len - sio.sio_resid);
285 			bread += (len - sio.sio_resid);
286 		}
287 
288 		if (ds->ds_bytesread >= db->db_bytesused) {
289 			mutex_enter(&ds->ds_egress_lock);
290 			db = dtv_stream_dequeue(ds);
291 			mutex_exit(&ds->ds_egress_lock);
292 			mutex_enter(&ds->ds_ingress_lock);
293 			dtv_stream_enqueue(ds, db);
294 			mutex_exit(&ds->ds_ingress_lock);
295 
296 			ds->ds_bytesread = 0;
297 		}
298 	}
299 
300 	return 0;
301 }
302 
303 int
304 dtv_buffer_poll(struct dtv_softc *sc, int events, lwp_t *l)
305 {
306 	struct dtv_stream *ds = &sc->sc_stream;
307 	int revents = 0;
308 #ifdef DTV_BUFFER_DEBUG
309 	struct dtv_buffer *db;
310 	size_t bufsize = 0;
311 #endif
312 
313 	mutex_enter(&ds->ds_egress_lock);
314 	if (!SIMPLEQ_EMPTY(&ds->ds_egress)) {
315 #ifdef DTV_BUFFER_DEBUG
316 		SIMPLEQ_FOREACH(db, &ds->ds_egress, db_entries)
317 			bufsize += db->db_bytesused;
318 #endif
319 		revents |= (POLLIN | POLLOUT | POLLPRI);
320 	} else {
321 		selrecord(l, &ds->ds_sel);
322 	}
323 	mutex_exit(&ds->ds_egress_lock);
324 
325 #ifdef DTV_BUFFER_DEBUG
326 	device_printf(sc->sc_dev, "%s: bufsize=%zu\n", __func__, bufsize);
327 #endif
328 
329 	return revents;
330 }
331