1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 buffer queues.
4 Copyright (C) 2003-2004 Kevin Thayer <nufan_wfk at yahoo.com>
5 Copyright (C) 2004 Chris Kennedy <c@groovy.org>
6 Copyright (C) 2005-2007 Hans Verkuil <hverkuil@xs4all.nl>
7
8 */
9
10 #include "ivtv-driver.h"
11 #include "ivtv-queue.h"
12
ivtv_buf_copy_from_user(struct ivtv_stream * s,struct ivtv_buffer * buf,const char __user * src,int copybytes)13 int ivtv_buf_copy_from_user(struct ivtv_stream *s, struct ivtv_buffer *buf, const char __user *src, int copybytes)
14 {
15 if (s->buf_size - buf->bytesused < copybytes)
16 copybytes = s->buf_size - buf->bytesused;
17 if (copy_from_user(buf->buf + buf->bytesused, src, copybytes)) {
18 return -EFAULT;
19 }
20 buf->bytesused += copybytes;
21 return copybytes;
22 }
23
ivtv_buf_swap(struct ivtv_buffer * buf)24 void ivtv_buf_swap(struct ivtv_buffer *buf)
25 {
26 int i;
27
28 for (i = 0; i < buf->bytesused; i += 4)
29 swab32s((u32 *)(buf->buf + i));
30 }
31
ivtv_queue_init(struct ivtv_queue * q)32 void ivtv_queue_init(struct ivtv_queue *q)
33 {
34 INIT_LIST_HEAD(&q->list);
35 q->buffers = 0;
36 q->length = 0;
37 q->bytesused = 0;
38 }
39
ivtv_enqueue(struct ivtv_stream * s,struct ivtv_buffer * buf,struct ivtv_queue * q)40 void ivtv_enqueue(struct ivtv_stream *s, struct ivtv_buffer *buf, struct ivtv_queue *q)
41 {
42 unsigned long flags;
43
44 /* clear the buffer if it is going to be enqueued to the free queue */
45 if (q == &s->q_free) {
46 buf->bytesused = 0;
47 buf->readpos = 0;
48 buf->b_flags = 0;
49 buf->dma_xfer_cnt = 0;
50 }
51 spin_lock_irqsave(&s->qlock, flags);
52 list_add_tail(&buf->list, &q->list);
53 q->buffers++;
54 q->length += s->buf_size;
55 q->bytesused += buf->bytesused - buf->readpos;
56 spin_unlock_irqrestore(&s->qlock, flags);
57 }
58
ivtv_dequeue(struct ivtv_stream * s,struct ivtv_queue * q)59 struct ivtv_buffer *ivtv_dequeue(struct ivtv_stream *s, struct ivtv_queue *q)
60 {
61 struct ivtv_buffer *buf = NULL;
62 unsigned long flags;
63
64 spin_lock_irqsave(&s->qlock, flags);
65 if (!list_empty(&q->list)) {
66 buf = list_entry(q->list.next, struct ivtv_buffer, list);
67 list_del_init(q->list.next);
68 q->buffers--;
69 q->length -= s->buf_size;
70 q->bytesused -= buf->bytesused - buf->readpos;
71 }
72 spin_unlock_irqrestore(&s->qlock, flags);
73 return buf;
74 }
75
ivtv_queue_move_buf(struct ivtv_stream * s,struct ivtv_queue * from,struct ivtv_queue * to,int clear)76 static void ivtv_queue_move_buf(struct ivtv_stream *s, struct ivtv_queue *from,
77 struct ivtv_queue *to, int clear)
78 {
79 struct ivtv_buffer *buf = list_entry(from->list.next, struct ivtv_buffer, list);
80
81 list_move_tail(from->list.next, &to->list);
82 from->buffers--;
83 from->length -= s->buf_size;
84 from->bytesused -= buf->bytesused - buf->readpos;
85 /* special handling for q_free */
86 if (clear)
87 buf->bytesused = buf->readpos = buf->b_flags = buf->dma_xfer_cnt = 0;
88 to->buffers++;
89 to->length += s->buf_size;
90 to->bytesused += buf->bytesused - buf->readpos;
91 }
92
93 /* Move 'needed_bytes' worth of buffers from queue 'from' into queue 'to'.
94 If 'needed_bytes' == 0, then move all buffers from 'from' into 'to'.
95 If 'steal' != NULL, then buffers may also taken from that queue if
96 needed, but only if 'from' is the free queue.
97
98 The buffer is automatically cleared if it goes to the free queue. It is
99 also cleared if buffers need to be taken from the 'steal' queue and
100 the 'from' queue is the free queue.
101
102 When 'from' is q_free, then needed_bytes is compared to the total
103 available buffer length, otherwise needed_bytes is compared to the
104 bytesused value. For the 'steal' queue the total available buffer
105 length is always used.
106
107 -ENOMEM is returned if the buffers could not be obtained, 0 if all
108 buffers where obtained from the 'from' list and if non-zero then
109 the number of stolen buffers is returned. */
ivtv_queue_move(struct ivtv_stream * s,struct ivtv_queue * from,struct ivtv_queue * steal,struct ivtv_queue * to,int needed_bytes)110 int ivtv_queue_move(struct ivtv_stream *s, struct ivtv_queue *from, struct ivtv_queue *steal,
111 struct ivtv_queue *to, int needed_bytes)
112 {
113 unsigned long flags;
114 int rc = 0;
115 int from_free = from == &s->q_free;
116 int to_free = to == &s->q_free;
117 int bytes_available, bytes_steal;
118
119 spin_lock_irqsave(&s->qlock, flags);
120 if (needed_bytes == 0) {
121 from_free = 1;
122 needed_bytes = from->length;
123 }
124
125 bytes_available = from_free ? from->length : from->bytesused;
126 bytes_steal = (from_free && steal) ? steal->length : 0;
127
128 if (bytes_available + bytes_steal < needed_bytes) {
129 spin_unlock_irqrestore(&s->qlock, flags);
130 return -ENOMEM;
131 }
132 while (steal && bytes_available < needed_bytes) {
133 struct ivtv_buffer *buf = list_entry(steal->list.prev, struct ivtv_buffer, list);
134 u16 dma_xfer_cnt = buf->dma_xfer_cnt;
135
136 /* move buffers from the tail of the 'steal' queue to the tail of the
137 'from' queue. Always copy all the buffers with the same dma_xfer_cnt
138 value, this ensures that you do not end up with partial frame data
139 if one frame is stored in multiple buffers. */
140 while (dma_xfer_cnt == buf->dma_xfer_cnt) {
141 list_move_tail(steal->list.prev, &from->list);
142 rc++;
143 steal->buffers--;
144 steal->length -= s->buf_size;
145 steal->bytesused -= buf->bytesused - buf->readpos;
146 buf->bytesused = buf->readpos = buf->b_flags = buf->dma_xfer_cnt = 0;
147 from->buffers++;
148 from->length += s->buf_size;
149 bytes_available += s->buf_size;
150 if (list_empty(&steal->list))
151 break;
152 buf = list_entry(steal->list.prev, struct ivtv_buffer, list);
153 }
154 }
155 if (from_free) {
156 u32 old_length = to->length;
157
158 while (to->length - old_length < needed_bytes) {
159 ivtv_queue_move_buf(s, from, to, 1);
160 }
161 }
162 else {
163 u32 old_bytesused = to->bytesused;
164
165 while (to->bytesused - old_bytesused < needed_bytes) {
166 ivtv_queue_move_buf(s, from, to, to_free);
167 }
168 }
169 spin_unlock_irqrestore(&s->qlock, flags);
170 return rc;
171 }
172
ivtv_flush_queues(struct ivtv_stream * s)173 void ivtv_flush_queues(struct ivtv_stream *s)
174 {
175 ivtv_queue_move(s, &s->q_io, NULL, &s->q_free, 0);
176 ivtv_queue_move(s, &s->q_full, NULL, &s->q_free, 0);
177 ivtv_queue_move(s, &s->q_dma, NULL, &s->q_free, 0);
178 ivtv_queue_move(s, &s->q_predma, NULL, &s->q_free, 0);
179 }
180
ivtv_stream_alloc(struct ivtv_stream * s)181 int ivtv_stream_alloc(struct ivtv_stream *s)
182 {
183 struct ivtv *itv = s->itv;
184 int SGsize = sizeof(struct ivtv_sg_host_element) * s->buffers;
185 int i;
186
187 if (s->buffers == 0)
188 return 0;
189
190 IVTV_DEBUG_INFO("Allocate %s%s stream: %d x %d buffers (%dkB total)\n",
191 s->dma != DMA_NONE ? "DMA " : "",
192 s->name, s->buffers, s->buf_size, s->buffers * s->buf_size / 1024);
193
194 s->sg_pending = kzalloc(SGsize, GFP_KERNEL|__GFP_NOWARN);
195 if (s->sg_pending == NULL) {
196 IVTV_ERR("Could not allocate sg_pending for %s stream\n", s->name);
197 return -ENOMEM;
198 }
199 s->sg_pending_size = 0;
200
201 s->sg_processing = kzalloc(SGsize, GFP_KERNEL|__GFP_NOWARN);
202 if (s->sg_processing == NULL) {
203 IVTV_ERR("Could not allocate sg_processing for %s stream\n", s->name);
204 kfree(s->sg_pending);
205 s->sg_pending = NULL;
206 return -ENOMEM;
207 }
208 s->sg_processing_size = 0;
209
210 s->sg_dma = kzalloc(sizeof(struct ivtv_sg_element),
211 GFP_KERNEL|__GFP_NOWARN);
212 if (s->sg_dma == NULL) {
213 IVTV_ERR("Could not allocate sg_dma for %s stream\n", s->name);
214 kfree(s->sg_pending);
215 s->sg_pending = NULL;
216 kfree(s->sg_processing);
217 s->sg_processing = NULL;
218 return -ENOMEM;
219 }
220 if (ivtv_might_use_dma(s)) {
221 s->sg_handle = dma_map_single(&itv->pdev->dev, s->sg_dma,
222 sizeof(struct ivtv_sg_element),
223 DMA_TO_DEVICE);
224 ivtv_stream_sync_for_cpu(s);
225 }
226
227 /* allocate stream buffers. Initially all buffers are in q_free. */
228 for (i = 0; i < s->buffers; i++) {
229 struct ivtv_buffer *buf = kzalloc(sizeof(struct ivtv_buffer),
230 GFP_KERNEL|__GFP_NOWARN);
231
232 if (buf == NULL)
233 break;
234 buf->buf = kmalloc(s->buf_size + 256, GFP_KERNEL|__GFP_NOWARN);
235 if (buf->buf == NULL) {
236 kfree(buf);
237 break;
238 }
239 INIT_LIST_HEAD(&buf->list);
240 if (ivtv_might_use_dma(s)) {
241 buf->dma_handle = dma_map_single(&s->itv->pdev->dev,
242 buf->buf, s->buf_size + 256, s->dma);
243 ivtv_buf_sync_for_cpu(s, buf);
244 }
245 ivtv_enqueue(s, buf, &s->q_free);
246 }
247 if (i == s->buffers)
248 return 0;
249 IVTV_ERR("Couldn't allocate buffers for %s stream\n", s->name);
250 ivtv_stream_free(s);
251 return -ENOMEM;
252 }
253
ivtv_stream_free(struct ivtv_stream * s)254 void ivtv_stream_free(struct ivtv_stream *s)
255 {
256 struct ivtv_buffer *buf;
257
258 /* move all buffers to q_free */
259 ivtv_flush_queues(s);
260
261 /* empty q_free */
262 while ((buf = ivtv_dequeue(s, &s->q_free))) {
263 if (ivtv_might_use_dma(s))
264 dma_unmap_single(&s->itv->pdev->dev, buf->dma_handle,
265 s->buf_size + 256, s->dma);
266 kfree(buf->buf);
267 kfree(buf);
268 }
269
270 /* Free SG Array/Lists */
271 if (s->sg_dma != NULL) {
272 if (s->sg_handle != IVTV_DMA_UNMAPPED) {
273 dma_unmap_single(&s->itv->pdev->dev, s->sg_handle,
274 sizeof(struct ivtv_sg_element),
275 DMA_TO_DEVICE);
276 s->sg_handle = IVTV_DMA_UNMAPPED;
277 }
278 kfree(s->sg_pending);
279 kfree(s->sg_processing);
280 kfree(s->sg_dma);
281 s->sg_pending = NULL;
282 s->sg_processing = NULL;
283 s->sg_dma = NULL;
284 s->sg_pending_size = 0;
285 s->sg_processing_size = 0;
286 }
287 }
288