1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * cx18 buffer queues
4 *
5 * Derived from ivtv-queue.c
6 *
7 * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
8 * Copyright (C) 2008 Andy Walls <awalls@md.metrocast.net>
9 */
10
11 #include "cx18-driver.h"
12 #include "cx18-queue.h"
13 #include "cx18-streams.h"
14 #include "cx18-scb.h"
15 #include "cx18-io.h"
16
cx18_buf_swap(struct cx18_buffer * buf)17 void cx18_buf_swap(struct cx18_buffer *buf)
18 {
19 int i;
20
21 for (i = 0; i < buf->bytesused; i += 4)
22 swab32s((u32 *)(buf->buf + i));
23 }
24
_cx18_mdl_swap(struct cx18_mdl * mdl)25 void _cx18_mdl_swap(struct cx18_mdl *mdl)
26 {
27 struct cx18_buffer *buf;
28
29 list_for_each_entry(buf, &mdl->buf_list, list) {
30 if (buf->bytesused == 0)
31 break;
32 cx18_buf_swap(buf);
33 }
34 }
35
cx18_queue_init(struct cx18_queue * q)36 void cx18_queue_init(struct cx18_queue *q)
37 {
38 INIT_LIST_HEAD(&q->list);
39 atomic_set(&q->depth, 0);
40 q->bytesused = 0;
41 }
42
_cx18_enqueue(struct cx18_stream * s,struct cx18_mdl * mdl,struct cx18_queue * q,int to_front)43 struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
44 struct cx18_queue *q, int to_front)
45 {
46 /* clear the mdl if it is not to be enqueued to the full queue */
47 if (q != &s->q_full) {
48 mdl->bytesused = 0;
49 mdl->readpos = 0;
50 mdl->m_flags = 0;
51 mdl->skipped = 0;
52 mdl->curr_buf = NULL;
53 }
54
55 /* q_busy is restricted to a max buffer count imposed by firmware */
56 if (q == &s->q_busy &&
57 atomic_read(&q->depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
58 q = &s->q_free;
59
60 spin_lock(&q->lock);
61
62 if (to_front)
63 list_add(&mdl->list, &q->list); /* LIFO */
64 else
65 list_add_tail(&mdl->list, &q->list); /* FIFO */
66 q->bytesused += mdl->bytesused - mdl->readpos;
67 atomic_inc(&q->depth);
68
69 spin_unlock(&q->lock);
70 return q;
71 }
72
cx18_dequeue(struct cx18_stream * s,struct cx18_queue * q)73 struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
74 {
75 struct cx18_mdl *mdl = NULL;
76
77 spin_lock(&q->lock);
78 if (!list_empty(&q->list)) {
79 mdl = list_first_entry(&q->list, struct cx18_mdl, list);
80 list_del_init(&mdl->list);
81 q->bytesused -= mdl->bytesused - mdl->readpos;
82 mdl->skipped = 0;
83 atomic_dec(&q->depth);
84 }
85 spin_unlock(&q->lock);
86 return mdl;
87 }
88
_cx18_mdl_update_bufs_for_cpu(struct cx18_stream * s,struct cx18_mdl * mdl)89 static void _cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
90 struct cx18_mdl *mdl)
91 {
92 struct cx18_buffer *buf;
93 u32 buf_size = s->buf_size;
94 u32 bytesused = mdl->bytesused;
95
96 list_for_each_entry(buf, &mdl->buf_list, list) {
97 buf->readpos = 0;
98 if (bytesused >= buf_size) {
99 buf->bytesused = buf_size;
100 bytesused -= buf_size;
101 } else {
102 buf->bytesused = bytesused;
103 bytesused = 0;
104 }
105 cx18_buf_sync_for_cpu(s, buf);
106 }
107 }
108
cx18_mdl_update_bufs_for_cpu(struct cx18_stream * s,struct cx18_mdl * mdl)109 static inline void cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
110 struct cx18_mdl *mdl)
111 {
112 struct cx18_buffer *buf;
113
114 if (list_is_singular(&mdl->buf_list)) {
115 buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
116 list);
117 buf->bytesused = mdl->bytesused;
118 buf->readpos = 0;
119 cx18_buf_sync_for_cpu(s, buf);
120 } else {
121 _cx18_mdl_update_bufs_for_cpu(s, mdl);
122 }
123 }
124
cx18_queue_get_mdl(struct cx18_stream * s,u32 id,u32 bytesused)125 struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
126 u32 bytesused)
127 {
128 struct cx18 *cx = s->cx;
129 struct cx18_mdl *mdl;
130 struct cx18_mdl *tmp;
131 struct cx18_mdl *ret = NULL;
132 LIST_HEAD(sweep_up);
133
134 /*
135 * We don't have to acquire multiple q locks here, because we are
136 * serialized by the single threaded work handler.
137 * MDLs from the firmware will thus remain in order as
138 * they are moved from q_busy to q_full or to the dvb ring buffer.
139 */
140 spin_lock(&s->q_busy.lock);
141 list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
142 /*
143 * We should find what the firmware told us is done,
144 * right at the front of the queue. If we don't, we likely have
145 * missed an mdl done message from the firmware.
146 * Once we skip an mdl repeatedly, relative to the size of
147 * q_busy, we have high confidence we've missed it.
148 */
149 if (mdl->id != id) {
150 mdl->skipped++;
151 if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
152 /* mdl must have fallen out of rotation */
153 CX18_WARN("Skipped %s, MDL %d, %d times - it must have dropped out of rotation\n",
154 s->name, mdl->id,
155 mdl->skipped);
156 /* Sweep it up to put it back into rotation */
157 list_move_tail(&mdl->list, &sweep_up);
158 atomic_dec(&s->q_busy.depth);
159 }
160 continue;
161 }
162 /*
163 * We pull the desired mdl off of the queue here. Something
164 * will have to put it back on a queue later.
165 */
166 list_del_init(&mdl->list);
167 atomic_dec(&s->q_busy.depth);
168 ret = mdl;
169 break;
170 }
171 spin_unlock(&s->q_busy.lock);
172
173 /*
174 * We found the mdl for which we were looking. Get it ready for
175 * the caller to put on q_full or in the dvb ring buffer.
176 */
177 if (ret != NULL) {
178 ret->bytesused = bytesused;
179 ret->skipped = 0;
180 /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
181 cx18_mdl_update_bufs_for_cpu(s, ret);
182 if (s->type != CX18_ENC_STREAM_TYPE_TS)
183 set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
184 }
185
186 /* Put any mdls the firmware is ignoring back into normal rotation */
187 list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
188 list_del_init(&mdl->list);
189 cx18_enqueue(s, mdl, &s->q_free);
190 }
191 return ret;
192 }
193
194 /* Move all mdls of a queue, while flushing the mdl */
cx18_queue_flush(struct cx18_stream * s,struct cx18_queue * q_src,struct cx18_queue * q_dst)195 static void cx18_queue_flush(struct cx18_stream *s,
196 struct cx18_queue *q_src, struct cx18_queue *q_dst)
197 {
198 struct cx18_mdl *mdl;
199
200 /* It only makes sense to flush to q_free or q_idle */
201 if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
202 return;
203
204 spin_lock(&q_src->lock);
205 spin_lock(&q_dst->lock);
206 while (!list_empty(&q_src->list)) {
207 mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
208 list_move_tail(&mdl->list, &q_dst->list);
209 mdl->bytesused = 0;
210 mdl->readpos = 0;
211 mdl->m_flags = 0;
212 mdl->skipped = 0;
213 mdl->curr_buf = NULL;
214 atomic_inc(&q_dst->depth);
215 }
216 cx18_queue_init(q_src);
217 spin_unlock(&q_src->lock);
218 spin_unlock(&q_dst->lock);
219 }
220
cx18_flush_queues(struct cx18_stream * s)221 void cx18_flush_queues(struct cx18_stream *s)
222 {
223 cx18_queue_flush(s, &s->q_busy, &s->q_free);
224 cx18_queue_flush(s, &s->q_full, &s->q_free);
225 }
226
227 /*
228 * Note, s->buf_pool is not protected by a lock,
229 * the stream better not have *anything* going on when calling this
230 */
cx18_unload_queues(struct cx18_stream * s)231 void cx18_unload_queues(struct cx18_stream *s)
232 {
233 struct cx18_queue *q_idle = &s->q_idle;
234 struct cx18_mdl *mdl;
235 struct cx18_buffer *buf;
236
237 /* Move all MDLS to q_idle */
238 cx18_queue_flush(s, &s->q_busy, q_idle);
239 cx18_queue_flush(s, &s->q_full, q_idle);
240 cx18_queue_flush(s, &s->q_free, q_idle);
241
242 /* Reset MDL id's and move all buffers back to the stream's buf_pool */
243 spin_lock(&q_idle->lock);
244 list_for_each_entry(mdl, &q_idle->list, list) {
245 while (!list_empty(&mdl->buf_list)) {
246 buf = list_first_entry(&mdl->buf_list,
247 struct cx18_buffer, list);
248 list_move_tail(&buf->list, &s->buf_pool);
249 buf->bytesused = 0;
250 buf->readpos = 0;
251 }
252 mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
253 /* all other mdl fields were cleared by cx18_queue_flush() */
254 }
255 spin_unlock(&q_idle->lock);
256 }
257
258 /*
259 * Note, s->buf_pool is not protected by a lock,
260 * the stream better not have *anything* going on when calling this
261 */
cx18_load_queues(struct cx18_stream * s)262 void cx18_load_queues(struct cx18_stream *s)
263 {
264 struct cx18 *cx = s->cx;
265 struct cx18_mdl *mdl;
266 struct cx18_buffer *buf;
267 int mdl_id;
268 int i;
269 u32 partial_buf_size;
270
271 /*
272 * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
273 * Excess MDLs are left on q_idle
274 * Excess buffers are left in buf_pool and/or on an MDL in q_idle
275 */
276 mdl_id = s->mdl_base_idx;
277 for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
278 mdl != NULL && i == s->bufs_per_mdl;
279 mdl = cx18_dequeue(s, &s->q_idle)) {
280
281 mdl->id = mdl_id;
282
283 for (i = 0; i < s->bufs_per_mdl; i++) {
284 if (list_empty(&s->buf_pool))
285 break;
286
287 buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
288 list);
289 list_move_tail(&buf->list, &mdl->buf_list);
290
291 /* update the firmware's MDL array with this buffer */
292 cx18_writel(cx, buf->dma_handle,
293 &cx->scb->cpu_mdl[mdl_id + i].paddr);
294 cx18_writel(cx, s->buf_size,
295 &cx->scb->cpu_mdl[mdl_id + i].length);
296 }
297
298 if (i == s->bufs_per_mdl) {
299 /*
300 * The encoder doesn't honor s->mdl_size. So in the
301 * case of a non-integral number of buffers to meet
302 * mdl_size, we lie about the size of the last buffer
303 * in the MDL to get the encoder to really only send
304 * us mdl_size bytes per MDL transfer.
305 */
306 partial_buf_size = s->mdl_size % s->buf_size;
307 if (partial_buf_size) {
308 cx18_writel(cx, partial_buf_size,
309 &cx->scb->cpu_mdl[mdl_id + i - 1].length);
310 }
311 cx18_enqueue(s, mdl, &s->q_free);
312 } else {
313 /* Not enough buffers for this MDL; we won't use it */
314 cx18_push(s, mdl, &s->q_idle);
315 }
316 mdl_id += i;
317 }
318 }
319
_cx18_mdl_sync_for_device(struct cx18_stream * s,struct cx18_mdl * mdl)320 void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
321 {
322 int dma = s->dma;
323 u32 buf_size = s->buf_size;
324 struct pci_dev *pci_dev = s->cx->pci_dev;
325 struct cx18_buffer *buf;
326
327 list_for_each_entry(buf, &mdl->buf_list, list)
328 dma_sync_single_for_device(&pci_dev->dev, buf->dma_handle,
329 buf_size, dma);
330 }
331
cx18_stream_alloc(struct cx18_stream * s)332 int cx18_stream_alloc(struct cx18_stream *s)
333 {
334 struct cx18 *cx = s->cx;
335 int i;
336
337 if (s->buffers == 0)
338 return 0;
339
340 CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%d.%02d kB total)\n",
341 s->name, s->buffers, s->buf_size,
342 s->buffers * s->buf_size / 1024,
343 (s->buffers * s->buf_size * 100 / 1024) % 100);
344
345 if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
346 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
347 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
348 ((char __iomem *)cx->scb->cpu_mdl));
349
350 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
351 CX18_ERR("Max buffers = %zu\n",
352 bufsz / sizeof(struct cx18_mdl_ent));
353 return -ENOMEM;
354 }
355
356 s->mdl_base_idx = cx->free_mdl_idx;
357
358 /* allocate stream buffers and MDLs */
359 for (i = 0; i < s->buffers; i++) {
360 struct cx18_mdl *mdl;
361 struct cx18_buffer *buf;
362
363 /* 1 MDL per buffer to handle the worst & also default case */
364 mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
365 if (mdl == NULL)
366 break;
367
368 buf = kzalloc(sizeof(struct cx18_buffer),
369 GFP_KERNEL|__GFP_NOWARN);
370 if (buf == NULL) {
371 kfree(mdl);
372 break;
373 }
374
375 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
376 if (buf->buf == NULL) {
377 kfree(mdl);
378 kfree(buf);
379 break;
380 }
381
382 INIT_LIST_HEAD(&mdl->list);
383 INIT_LIST_HEAD(&mdl->buf_list);
384 mdl->id = s->mdl_base_idx; /* a somewhat safe value */
385 cx18_enqueue(s, mdl, &s->q_idle);
386
387 INIT_LIST_HEAD(&buf->list);
388 buf->dma_handle = dma_map_single(&s->cx->pci_dev->dev,
389 buf->buf, s->buf_size,
390 s->dma);
391 cx18_buf_sync_for_cpu(s, buf);
392 list_add_tail(&buf->list, &s->buf_pool);
393 }
394 if (i == s->buffers) {
395 cx->free_mdl_idx += s->buffers;
396 return 0;
397 }
398 CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
399 cx18_stream_free(s);
400 return -ENOMEM;
401 }
402
cx18_stream_free(struct cx18_stream * s)403 void cx18_stream_free(struct cx18_stream *s)
404 {
405 struct cx18_mdl *mdl;
406 struct cx18_buffer *buf;
407 struct cx18 *cx = s->cx;
408
409 CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name);
410
411 /* move all buffers to buf_pool and all MDLs to q_idle */
412 cx18_unload_queues(s);
413
414 /* empty q_idle */
415 while ((mdl = cx18_dequeue(s, &s->q_idle)))
416 kfree(mdl);
417
418 /* empty buf_pool */
419 while (!list_empty(&s->buf_pool)) {
420 buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list);
421 list_del_init(&buf->list);
422
423 dma_unmap_single(&s->cx->pci_dev->dev, buf->dma_handle,
424 s->buf_size, s->dma);
425 kfree(buf->buf);
426 kfree(buf);
427 }
428 }
429