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1 | /* | |
2 | * sound/oss/midibuf.c | |
3 | * | |
4 | * Device file manager for /dev/midi# | |
5 | */ | |
6 | /* | |
7 | * Copyright (C) by Hannu Savolainen 1993-1997 | |
8 | * | |
9 | * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL) | |
10 | * Version 2 (June 1991). See the "COPYING" file distributed with this software | |
11 | * for more info. | |
12 | */ | |
13 | /* | |
14 | * Thomas Sailer : ioctl code reworked (vmalloc/vfree removed) | |
15 | */ | |
16 | #include <linux/stddef.h> | |
17 | #include <linux/kmod.h> | |
18 | #include <linux/spinlock.h> | |
19 | #include <linux/sched/signal.h> | |
20 | ||
21 | #define MIDIBUF_C | |
22 | ||
23 | #include "sound_config.h" | |
24 | ||
25 | ||
26 | /* | |
27 | * Don't make MAX_QUEUE_SIZE larger than 4000 | |
28 | */ | |
29 | ||
30 | #define MAX_QUEUE_SIZE 4000 | |
31 | ||
32 | static wait_queue_head_t midi_sleeper[MAX_MIDI_DEV]; | |
33 | static wait_queue_head_t input_sleeper[MAX_MIDI_DEV]; | |
34 | ||
35 | struct midi_buf | |
36 | { | |
37 | int len, head, tail; | |
38 | unsigned char queue[MAX_QUEUE_SIZE]; | |
39 | }; | |
40 | ||
41 | struct midi_parms | |
42 | { | |
43 | long prech_timeout; /* | |
44 | * Timeout before the first ch | |
45 | */ | |
46 | }; | |
47 | ||
48 | static struct midi_buf *midi_out_buf[MAX_MIDI_DEV] = {NULL}; | |
49 | static struct midi_buf *midi_in_buf[MAX_MIDI_DEV] = {NULL}; | |
50 | static struct midi_parms parms[MAX_MIDI_DEV]; | |
51 | ||
52 | static void midi_poll(unsigned long dummy); | |
53 | ||
54 | ||
55 | static DEFINE_TIMER(poll_timer, midi_poll, 0, 0); | |
56 | ||
57 | static volatile int open_devs; | |
58 | static DEFINE_SPINLOCK(lock); | |
59 | ||
60 | #define DATA_AVAIL(q) (q->len) | |
61 | #define SPACE_AVAIL(q) (MAX_QUEUE_SIZE - q->len) | |
62 | ||
63 | #define QUEUE_BYTE(q, data) \ | |
64 | if (SPACE_AVAIL(q)) \ | |
65 | { \ | |
66 | unsigned long flags; \ | |
67 | spin_lock_irqsave(&lock, flags); \ | |
68 | q->queue[q->tail] = (data); \ | |
69 | q->len++; q->tail = (q->tail+1) % MAX_QUEUE_SIZE; \ | |
70 | spin_unlock_irqrestore(&lock, flags); \ | |
71 | } | |
72 | ||
73 | #define REMOVE_BYTE(q, data) \ | |
74 | if (DATA_AVAIL(q)) \ | |
75 | { \ | |
76 | unsigned long flags; \ | |
77 | spin_lock_irqsave(&lock, flags); \ | |
78 | data = q->queue[q->head]; \ | |
79 | q->len--; q->head = (q->head+1) % MAX_QUEUE_SIZE; \ | |
80 | spin_unlock_irqrestore(&lock, flags); \ | |
81 | } | |
82 | ||
83 | static void drain_midi_queue(int dev) | |
84 | { | |
85 | ||
86 | /* | |
87 | * Give the Midi driver time to drain its output queues | |
88 | */ | |
89 | ||
90 | if (midi_devs[dev]->buffer_status != NULL) | |
91 | wait_event_interruptible_timeout(midi_sleeper[dev], | |
92 | !midi_devs[dev]->buffer_status(dev), HZ/10); | |
93 | } | |
94 | ||
95 | static void midi_input_intr(int dev, unsigned char data) | |
96 | { | |
97 | if (midi_in_buf[dev] == NULL) | |
98 | return; | |
99 | ||
100 | if (data == 0xfe) /* | |
101 | * Active sensing | |
102 | */ | |
103 | return; /* | |
104 | * Ignore | |
105 | */ | |
106 | ||
107 | if (SPACE_AVAIL(midi_in_buf[dev])) { | |
108 | QUEUE_BYTE(midi_in_buf[dev], data); | |
109 | wake_up(&input_sleeper[dev]); | |
110 | } | |
111 | } | |
112 | ||
113 | static void midi_output_intr(int dev) | |
114 | { | |
115 | /* | |
116 | * Currently NOP | |
117 | */ | |
118 | } | |
119 | ||
120 | static void midi_poll(unsigned long dummy) | |
121 | { | |
122 | unsigned long flags; | |
123 | int dev; | |
124 | ||
125 | spin_lock_irqsave(&lock, flags); | |
126 | if (open_devs) | |
127 | { | |
128 | for (dev = 0; dev < num_midis; dev++) | |
129 | if (midi_devs[dev] != NULL && midi_out_buf[dev] != NULL) | |
130 | { | |
131 | while (DATA_AVAIL(midi_out_buf[dev])) | |
132 | { | |
133 | int ok; | |
134 | int c = midi_out_buf[dev]->queue[midi_out_buf[dev]->head]; | |
135 | ||
136 | spin_unlock_irqrestore(&lock,flags);/* Give some time to others */ | |
137 | ok = midi_devs[dev]->outputc(dev, c); | |
138 | spin_lock_irqsave(&lock, flags); | |
139 | if (!ok) | |
140 | break; | |
141 | midi_out_buf[dev]->head = (midi_out_buf[dev]->head + 1) % MAX_QUEUE_SIZE; | |
142 | midi_out_buf[dev]->len--; | |
143 | } | |
144 | ||
145 | if (DATA_AVAIL(midi_out_buf[dev]) < 100) | |
146 | wake_up(&midi_sleeper[dev]); | |
147 | } | |
148 | poll_timer.expires = (1) + jiffies; | |
149 | add_timer(&poll_timer); | |
150 | /* | |
151 | * Come back later | |
152 | */ | |
153 | } | |
154 | spin_unlock_irqrestore(&lock, flags); | |
155 | } | |
156 | ||
157 | int MIDIbuf_open(int dev, struct file *file) | |
158 | { | |
159 | int mode, err; | |
160 | ||
161 | dev = dev >> 4; | |
162 | mode = translate_mode(file); | |
163 | ||
164 | if (num_midis > MAX_MIDI_DEV) | |
165 | { | |
166 | printk(KERN_ERR "midi: Too many midi interfaces\n"); | |
167 | num_midis = MAX_MIDI_DEV; | |
168 | } | |
169 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) | |
170 | return -ENXIO; | |
171 | /* | |
172 | * Interrupts disabled. Be careful | |
173 | */ | |
174 | ||
175 | module_put(midi_devs[dev]->owner); | |
176 | ||
177 | if ((err = midi_devs[dev]->open(dev, mode, | |
178 | midi_input_intr, midi_output_intr)) < 0) | |
179 | return err; | |
180 | ||
181 | parms[dev].prech_timeout = MAX_SCHEDULE_TIMEOUT; | |
182 | midi_in_buf[dev] = vmalloc(sizeof(struct midi_buf)); | |
183 | ||
184 | if (midi_in_buf[dev] == NULL) | |
185 | { | |
186 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); | |
187 | midi_devs[dev]->close(dev); | |
188 | return -EIO; | |
189 | } | |
190 | midi_in_buf[dev]->len = midi_in_buf[dev]->head = midi_in_buf[dev]->tail = 0; | |
191 | ||
192 | midi_out_buf[dev] = vmalloc(sizeof(struct midi_buf)); | |
193 | ||
194 | if (midi_out_buf[dev] == NULL) | |
195 | { | |
196 | printk(KERN_WARNING "midi: Can't allocate buffer\n"); | |
197 | midi_devs[dev]->close(dev); | |
198 | vfree(midi_in_buf[dev]); | |
199 | midi_in_buf[dev] = NULL; | |
200 | return -EIO; | |
201 | } | |
202 | midi_out_buf[dev]->len = midi_out_buf[dev]->head = midi_out_buf[dev]->tail = 0; | |
203 | open_devs++; | |
204 | ||
205 | init_waitqueue_head(&midi_sleeper[dev]); | |
206 | init_waitqueue_head(&input_sleeper[dev]); | |
207 | ||
208 | if (open_devs < 2) /* This was first open */ | |
209 | { | |
210 | poll_timer.expires = 1 + jiffies; | |
211 | add_timer(&poll_timer); /* Start polling */ | |
212 | } | |
213 | return err; | |
214 | } | |
215 | ||
216 | void MIDIbuf_release(int dev, struct file *file) | |
217 | { | |
218 | int mode; | |
219 | ||
220 | dev = dev >> 4; | |
221 | mode = translate_mode(file); | |
222 | ||
223 | if (dev < 0 || dev >= num_midis || midi_devs[dev] == NULL) | |
224 | return; | |
225 | ||
226 | /* | |
227 | * Wait until the queue is empty | |
228 | */ | |
229 | ||
230 | if (mode != OPEN_READ) | |
231 | { | |
232 | midi_devs[dev]->outputc(dev, 0xfe); /* | |
233 | * Active sensing to shut the | |
234 | * devices | |
235 | */ | |
236 | ||
237 | wait_event_interruptible(midi_sleeper[dev], | |
238 | !DATA_AVAIL(midi_out_buf[dev])); | |
239 | /* | |
240 | * Sync | |
241 | */ | |
242 | ||
243 | drain_midi_queue(dev); /* | |
244 | * Ensure the output queues are empty | |
245 | */ | |
246 | } | |
247 | ||
248 | midi_devs[dev]->close(dev); | |
249 | ||
250 | open_devs--; | |
251 | if (open_devs == 0) | |
252 | del_timer_sync(&poll_timer); | |
253 | vfree(midi_in_buf[dev]); | |
254 | vfree(midi_out_buf[dev]); | |
255 | midi_in_buf[dev] = NULL; | |
256 | midi_out_buf[dev] = NULL; | |
257 | ||
258 | module_put(midi_devs[dev]->owner); | |
259 | } | |
260 | ||
261 | int MIDIbuf_write(int dev, struct file *file, const char __user *buf, int count) | |
262 | { | |
263 | int c, n, i; | |
264 | unsigned char tmp_data; | |
265 | ||
266 | dev = dev >> 4; | |
267 | ||
268 | if (!count) | |
269 | return 0; | |
270 | ||
271 | c = 0; | |
272 | ||
273 | while (c < count) | |
274 | { | |
275 | n = SPACE_AVAIL(midi_out_buf[dev]); | |
276 | ||
277 | if (n == 0) { /* | |
278 | * No space just now. | |
279 | */ | |
280 | ||
281 | if (file->f_flags & O_NONBLOCK) { | |
282 | c = -EAGAIN; | |
283 | goto out; | |
284 | } | |
285 | ||
286 | if (wait_event_interruptible(midi_sleeper[dev], | |
287 | SPACE_AVAIL(midi_out_buf[dev]))) | |
288 | { | |
289 | c = -EINTR; | |
290 | goto out; | |
291 | } | |
292 | n = SPACE_AVAIL(midi_out_buf[dev]); | |
293 | } | |
294 | if (n > (count - c)) | |
295 | n = count - c; | |
296 | ||
297 | for (i = 0; i < n; i++) | |
298 | { | |
299 | /* BROKE BROKE BROKE - CAN'T DO THIS WITH CLI !! */ | |
300 | /* yes, think the same, so I removed the cli() brackets | |
301 | QUEUE_BYTE is protected against interrupts */ | |
302 | if (copy_from_user((char *) &tmp_data, &(buf)[c], 1)) { | |
303 | c = -EFAULT; | |
304 | goto out; | |
305 | } | |
306 | QUEUE_BYTE(midi_out_buf[dev], tmp_data); | |
307 | c++; | |
308 | } | |
309 | } | |
310 | out: | |
311 | return c; | |
312 | } | |
313 | ||
314 | ||
315 | int MIDIbuf_read(int dev, struct file *file, char __user *buf, int count) | |
316 | { | |
317 | int n, c = 0; | |
318 | unsigned char tmp_data; | |
319 | ||
320 | dev = dev >> 4; | |
321 | ||
322 | if (!DATA_AVAIL(midi_in_buf[dev])) { /* | |
323 | * No data yet, wait | |
324 | */ | |
325 | if (file->f_flags & O_NONBLOCK) { | |
326 | c = -EAGAIN; | |
327 | goto out; | |
328 | } | |
329 | wait_event_interruptible_timeout(input_sleeper[dev], | |
330 | DATA_AVAIL(midi_in_buf[dev]), | |
331 | parms[dev].prech_timeout); | |
332 | ||
333 | if (signal_pending(current)) | |
334 | c = -EINTR; /* The user is getting restless */ | |
335 | } | |
336 | if (c == 0 && DATA_AVAIL(midi_in_buf[dev])) /* | |
337 | * Got some bytes | |
338 | */ | |
339 | { | |
340 | n = DATA_AVAIL(midi_in_buf[dev]); | |
341 | if (n > count) | |
342 | n = count; | |
343 | c = 0; | |
344 | ||
345 | while (c < n) | |
346 | { | |
347 | char *fixit; | |
348 | REMOVE_BYTE(midi_in_buf[dev], tmp_data); | |
349 | fixit = (char *) &tmp_data; | |
350 | /* BROKE BROKE BROKE */ | |
351 | /* yes removed the cli() brackets again | |
352 | should q->len,tail&head be atomic_t? */ | |
353 | if (copy_to_user(&(buf)[c], fixit, 1)) { | |
354 | c = -EFAULT; | |
355 | goto out; | |
356 | } | |
357 | c++; | |
358 | } | |
359 | } | |
360 | out: | |
361 | return c; | |
362 | } | |
363 | ||
364 | int MIDIbuf_ioctl(int dev, struct file *file, | |
365 | unsigned int cmd, void __user *arg) | |
366 | { | |
367 | int val; | |
368 | ||
369 | dev = dev >> 4; | |
370 | ||
371 | if (((cmd >> 8) & 0xff) == 'C') | |
372 | { | |
373 | if (midi_devs[dev]->coproc) /* Coprocessor ioctl */ | |
374 | return midi_devs[dev]->coproc->ioctl(midi_devs[dev]->coproc->devc, cmd, arg, 0); | |
375 | /* printk("/dev/midi%d: No coprocessor for this device\n", dev);*/ | |
376 | return -ENXIO; | |
377 | } | |
378 | else | |
379 | { | |
380 | switch (cmd) | |
381 | { | |
382 | case SNDCTL_MIDI_PRETIME: | |
383 | if (get_user(val, (int __user *)arg)) | |
384 | return -EFAULT; | |
385 | if (val < 0) | |
386 | val = 0; | |
387 | val = (HZ * val) / 10; | |
388 | parms[dev].prech_timeout = val; | |
389 | return put_user(val, (int __user *)arg); | |
390 | ||
391 | default: | |
392 | if (!midi_devs[dev]->ioctl) | |
393 | return -EINVAL; | |
394 | return midi_devs[dev]->ioctl(dev, cmd, arg); | |
395 | } | |
396 | } | |
397 | } | |
398 | ||
399 | /* No kernel lock - fine */ | |
400 | unsigned int MIDIbuf_poll(int dev, struct file *file, poll_table * wait) | |
401 | { | |
402 | unsigned int mask = 0; | |
403 | ||
404 | dev = dev >> 4; | |
405 | ||
406 | /* input */ | |
407 | poll_wait(file, &input_sleeper[dev], wait); | |
408 | if (DATA_AVAIL(midi_in_buf[dev])) | |
409 | mask |= POLLIN | POLLRDNORM; | |
410 | ||
411 | /* output */ | |
412 | poll_wait(file, &midi_sleeper[dev], wait); | |
413 | if (!SPACE_AVAIL(midi_out_buf[dev])) | |
414 | mask |= POLLOUT | POLLWRNORM; | |
415 | ||
416 | return mask; | |
417 | } | |
418 | ||
419 | ||
420 | int MIDIbuf_avail(int dev) | |
421 | { | |
422 | if (midi_in_buf[dev]) | |
423 | return DATA_AVAIL (midi_in_buf[dev]); | |
424 | return 0; | |
425 | } | |
426 | EXPORT_SYMBOL(MIDIbuf_avail); | |
427 |