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29#include <linux/errno.h>
30#include <linux/kernel.h>
31#include <linux/module.h>
32#include <linux/sched.h>
33#include <linux/string.h>
34#include <asm/uaccess.h>
35
36#include "dvb_ringbuffer.h"
37
38#define PKT_READY 0
39#define PKT_DISPOSED 1
40
41
42void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len)
43{
44 rbuf->pread=rbuf->pwrite=0;
45 rbuf->data=data;
46 rbuf->size=len;
47 rbuf->error=0;
48
49 init_waitqueue_head(&rbuf->queue);
50
51 spin_lock_init(&(rbuf->lock));
52}
53
54
55
56int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf)
57{
58 return (rbuf->pread==rbuf->pwrite);
59}
60
61
62
63ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf)
64{
65 ssize_t free;
66
67 free = rbuf->pread - rbuf->pwrite;
68 if (free <= 0)
69 free += rbuf->size;
70 return free-1;
71}
72
73
74
75ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf)
76{
77 ssize_t avail;
78
79 avail = rbuf->pwrite - rbuf->pread;
80 if (avail < 0)
81 avail += rbuf->size;
82 return avail;
83}
84
85
86
87void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf)
88{
89 rbuf->pread = rbuf->pwrite;
90 rbuf->error = 0;
91}
92
93void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf)
94{
95 rbuf->pread = rbuf->pwrite = 0;
96 rbuf->error = 0;
97}
98
99void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf)
100{
101 unsigned long flags;
102
103 spin_lock_irqsave(&rbuf->lock, flags);
104 dvb_ringbuffer_flush(rbuf);
105 spin_unlock_irqrestore(&rbuf->lock, flags);
106
107 wake_up(&rbuf->queue);
108}
109
110ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf, u8 __user *buf, size_t len)
111{
112 size_t todo = len;
113 size_t split;
114
115 split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
116 if (split > 0) {
117 if (copy_to_user(buf, rbuf->data+rbuf->pread, split))
118 return -EFAULT;
119 buf += split;
120 todo -= split;
121 rbuf->pread = 0;
122 }
123 if (copy_to_user(buf, rbuf->data+rbuf->pread, todo))
124 return -EFAULT;
125
126 rbuf->pread = (rbuf->pread + todo) % rbuf->size;
127
128 return len;
129}
130
131void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, size_t len)
132{
133 size_t todo = len;
134 size_t split;
135
136 split = (rbuf->pread + len > rbuf->size) ? rbuf->size - rbuf->pread : 0;
137 if (split > 0) {
138 memcpy(buf, rbuf->data+rbuf->pread, split);
139 buf += split;
140 todo -= split;
141 rbuf->pread = 0;
142 }
143 memcpy(buf, rbuf->data+rbuf->pread, todo);
144
145 rbuf->pread = (rbuf->pread + todo) % rbuf->size;
146}
147
148
149ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, size_t len)
150{
151 size_t todo = len;
152 size_t split;
153
154 split = (rbuf->pwrite + len > rbuf->size) ? rbuf->size - rbuf->pwrite : 0;
155
156 if (split > 0) {
157 memcpy(rbuf->data+rbuf->pwrite, buf, split);
158 buf += split;
159 todo -= split;
160 rbuf->pwrite = 0;
161 }
162 memcpy(rbuf->data+rbuf->pwrite, buf, todo);
163 rbuf->pwrite = (rbuf->pwrite + todo) % rbuf->size;
164
165 return len;
166}
167
168ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, size_t len)
169{
170 int status;
171 ssize_t oldpwrite = rbuf->pwrite;
172
173 DVB_RINGBUFFER_WRITE_BYTE(rbuf, len >> 8);
174 DVB_RINGBUFFER_WRITE_BYTE(rbuf, len & 0xff);
175 DVB_RINGBUFFER_WRITE_BYTE(rbuf, PKT_READY);
176 status = dvb_ringbuffer_write(rbuf, buf, len);
177
178 if (status < 0) rbuf->pwrite = oldpwrite;
179 return status;
180}
181
182ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf, size_t idx,
183 int offset, u8 __user *buf, size_t len)
184{
185 size_t todo;
186 size_t split;
187 size_t pktlen;
188
189 pktlen = rbuf->data[idx] << 8;
190 pktlen |= rbuf->data[(idx + 1) % rbuf->size];
191 if (offset > pktlen) return -EINVAL;
192 if ((offset + len) > pktlen) len = pktlen - offset;
193
194 idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
195 todo = len;
196 split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
197 if (split > 0) {
198 if (copy_to_user(buf, rbuf->data+idx, split))
199 return -EFAULT;
200 buf += split;
201 todo -= split;
202 idx = 0;
203 }
204 if (copy_to_user(buf, rbuf->data+idx, todo))
205 return -EFAULT;
206
207 return len;
208}
209
210ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
211 int offset, u8* buf, size_t len)
212{
213 size_t todo;
214 size_t split;
215 size_t pktlen;
216
217 pktlen = rbuf->data[idx] << 8;
218 pktlen |= rbuf->data[(idx + 1) % rbuf->size];
219 if (offset > pktlen) return -EINVAL;
220 if ((offset + len) > pktlen) len = pktlen - offset;
221
222 idx = (idx + DVB_RINGBUFFER_PKTHDRSIZE + offset) % rbuf->size;
223 todo = len;
224 split = ((idx + len) > rbuf->size) ? rbuf->size - idx : 0;
225 if (split > 0) {
226 memcpy(buf, rbuf->data+idx, split);
227 buf += split;
228 todo -= split;
229 idx = 0;
230 }
231 memcpy(buf, rbuf->data+idx, todo);
232 return len;
233}
234
235void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx)
236{
237 size_t pktlen;
238
239 rbuf->data[(idx + 2) % rbuf->size] = PKT_DISPOSED;
240
241
242 while(dvb_ringbuffer_avail(rbuf) > DVB_RINGBUFFER_PKTHDRSIZE) {
243 if (DVB_RINGBUFFER_PEEK(rbuf, 2) == PKT_DISPOSED) {
244 pktlen = DVB_RINGBUFFER_PEEK(rbuf, 0) << 8;
245 pktlen |= DVB_RINGBUFFER_PEEK(rbuf, 1);
246 DVB_RINGBUFFER_SKIP(rbuf, pktlen + DVB_RINGBUFFER_PKTHDRSIZE);
247 } else {
248
249 break;
250 }
251 }
252}
253
254ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen)
255{
256 int consumed;
257 int curpktlen;
258 int curpktstatus;
259
260 if (idx == -1) {
261 idx = rbuf->pread;
262 } else {
263 curpktlen = rbuf->data[idx] << 8;
264 curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
265 idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
266 }
267
268 consumed = (idx - rbuf->pread) % rbuf->size;
269
270 while((dvb_ringbuffer_avail(rbuf) - consumed) > DVB_RINGBUFFER_PKTHDRSIZE) {
271
272 curpktlen = rbuf->data[idx] << 8;
273 curpktlen |= rbuf->data[(idx + 1) % rbuf->size];
274 curpktstatus = rbuf->data[(idx + 2) % rbuf->size];
275
276 if (curpktstatus == PKT_READY) {
277 *pktlen = curpktlen;
278 return idx;
279 }
280
281 consumed += curpktlen + DVB_RINGBUFFER_PKTHDRSIZE;
282 idx = (idx + curpktlen + DVB_RINGBUFFER_PKTHDRSIZE) % rbuf->size;
283 }
284
285
286 return -1;
287}
288
289
290
291EXPORT_SYMBOL(dvb_ringbuffer_init);
292EXPORT_SYMBOL(dvb_ringbuffer_empty);
293EXPORT_SYMBOL(dvb_ringbuffer_free);
294EXPORT_SYMBOL(dvb_ringbuffer_avail);
295EXPORT_SYMBOL(dvb_ringbuffer_flush_spinlock_wakeup);
296EXPORT_SYMBOL(dvb_ringbuffer_read_user);
297EXPORT_SYMBOL(dvb_ringbuffer_read);
298EXPORT_SYMBOL(dvb_ringbuffer_write);
299