1 /*
2  *  ALSA sequencer Memory Manager
3  *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
4  *                        Jaroslav Kysela <perex@perex.cz>
5  *                2000 by Takashi Iwai <tiwai@suse.de>
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #include <linux/init.h>
24 #include <linux/export.h>
25 #include <linux/slab.h>
26 #include <linux/vmalloc.h>
27 #include <sound/core.h>
28 
29 #include <sound/seq_kernel.h>
30 #include "seq_memory.h"
31 #include "seq_queue.h"
32 #include "seq_info.h"
33 #include "seq_lock.h"
34 
snd_seq_pool_available(struct snd_seq_pool * pool)35 static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
36 {
37 	return pool->total_elements - atomic_read(&pool->counter);
38 }
39 
snd_seq_output_ok(struct snd_seq_pool * pool)40 static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
41 {
42 	return snd_seq_pool_available(pool) >= pool->room;
43 }
44 
45 /*
46  * Variable length event:
47  * The event like sysex uses variable length type.
48  * The external data may be stored in three different formats.
49  * 1) kernel space
50  *    This is the normal case.
51  *      ext.data.len = length
52  *      ext.data.ptr = buffer pointer
53  * 2) user space
54  *    When an event is generated via read(), the external data is
55  *    kept in user space until expanded.
56  *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
57  *      ext.data.ptr = userspace pointer
58  * 3) chained cells
59  *    When the variable length event is enqueued (in prioq or fifo),
60  *    the external data is decomposed to several cells.
61  *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
62  *      ext.data.ptr = the additiona cell head
63  *         -> cell.next -> cell.next -> ..
64  */
65 
66 /*
67  * exported:
68  * call dump function to expand external data.
69  */
70 
get_var_len(const struct snd_seq_event * event)71 static int get_var_len(const struct snd_seq_event *event)
72 {
73 	if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
74 		return -EINVAL;
75 
76 	return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
77 }
78 
snd_seq_dump_var_event(const struct snd_seq_event * event,snd_seq_dump_func_t func,void * private_data)79 int snd_seq_dump_var_event(const struct snd_seq_event *event,
80 			   snd_seq_dump_func_t func, void *private_data)
81 {
82 	int len, err;
83 	struct snd_seq_event_cell *cell;
84 
85 	if ((len = get_var_len(event)) <= 0)
86 		return len;
87 
88 	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
89 		char buf[32];
90 		char __user *curptr = (char __force __user *)event->data.ext.ptr;
91 		while (len > 0) {
92 			int size = sizeof(buf);
93 			if (len < size)
94 				size = len;
95 			if (copy_from_user(buf, curptr, size))
96 				return -EFAULT;
97 			err = func(private_data, buf, size);
98 			if (err < 0)
99 				return err;
100 			curptr += size;
101 			len -= size;
102 		}
103 		return 0;
104 	} if (! (event->data.ext.len & SNDRV_SEQ_EXT_CHAINED)) {
105 		return func(private_data, event->data.ext.ptr, len);
106 	}
107 
108 	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
109 	for (; len > 0 && cell; cell = cell->next) {
110 		int size = sizeof(struct snd_seq_event);
111 		if (len < size)
112 			size = len;
113 		err = func(private_data, &cell->event, size);
114 		if (err < 0)
115 			return err;
116 		len -= size;
117 	}
118 	return 0;
119 }
120 
121 EXPORT_SYMBOL(snd_seq_dump_var_event);
122 
123 
124 /*
125  * exported:
126  * expand the variable length event to linear buffer space.
127  */
128 
seq_copy_in_kernel(char ** bufptr,const void * src,int size)129 static int seq_copy_in_kernel(char **bufptr, const void *src, int size)
130 {
131 	memcpy(*bufptr, src, size);
132 	*bufptr += size;
133 	return 0;
134 }
135 
seq_copy_in_user(char __user ** bufptr,const void * src,int size)136 static int seq_copy_in_user(char __user **bufptr, const void *src, int size)
137 {
138 	if (copy_to_user(*bufptr, src, size))
139 		return -EFAULT;
140 	*bufptr += size;
141 	return 0;
142 }
143 
snd_seq_expand_var_event(const struct snd_seq_event * event,int count,char * buf,int in_kernel,int size_aligned)144 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
145 			     int in_kernel, int size_aligned)
146 {
147 	int len, newlen;
148 	int err;
149 
150 	if ((len = get_var_len(event)) < 0)
151 		return len;
152 	newlen = len;
153 	if (size_aligned > 0)
154 		newlen = roundup(len, size_aligned);
155 	if (count < newlen)
156 		return -EAGAIN;
157 
158 	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
159 		if (! in_kernel)
160 			return -EINVAL;
161 		if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
162 			return -EFAULT;
163 		return newlen;
164 	}
165 	err = snd_seq_dump_var_event(event,
166 				     in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel :
167 				     (snd_seq_dump_func_t)seq_copy_in_user,
168 				     &buf);
169 	return err < 0 ? err : newlen;
170 }
171 
172 EXPORT_SYMBOL(snd_seq_expand_var_event);
173 
174 /*
175  * release this cell, free extended data if available
176  */
177 
free_cell(struct snd_seq_pool * pool,struct snd_seq_event_cell * cell)178 static inline void free_cell(struct snd_seq_pool *pool,
179 			     struct snd_seq_event_cell *cell)
180 {
181 	cell->next = pool->free;
182 	pool->free = cell;
183 	atomic_dec(&pool->counter);
184 }
185 
snd_seq_cell_free(struct snd_seq_event_cell * cell)186 void snd_seq_cell_free(struct snd_seq_event_cell * cell)
187 {
188 	unsigned long flags;
189 	struct snd_seq_pool *pool;
190 
191 	if (snd_BUG_ON(!cell))
192 		return;
193 	pool = cell->pool;
194 	if (snd_BUG_ON(!pool))
195 		return;
196 
197 	spin_lock_irqsave(&pool->lock, flags);
198 	free_cell(pool, cell);
199 	if (snd_seq_ev_is_variable(&cell->event)) {
200 		if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
201 			struct snd_seq_event_cell *curp, *nextptr;
202 			curp = cell->event.data.ext.ptr;
203 			for (; curp; curp = nextptr) {
204 				nextptr = curp->next;
205 				curp->next = pool->free;
206 				free_cell(pool, curp);
207 			}
208 		}
209 	}
210 	if (waitqueue_active(&pool->output_sleep)) {
211 		/* has enough space now? */
212 		if (snd_seq_output_ok(pool))
213 			wake_up(&pool->output_sleep);
214 	}
215 	spin_unlock_irqrestore(&pool->lock, flags);
216 }
217 
218 
219 /*
220  * allocate an event cell.
221  */
snd_seq_cell_alloc(struct snd_seq_pool * pool,struct snd_seq_event_cell ** cellp,int nonblock,struct file * file)222 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
223 			      struct snd_seq_event_cell **cellp,
224 			      int nonblock, struct file *file)
225 {
226 	struct snd_seq_event_cell *cell;
227 	unsigned long flags;
228 	int err = -EAGAIN;
229 	wait_queue_t wait;
230 
231 	if (pool == NULL)
232 		return -EINVAL;
233 
234 	*cellp = NULL;
235 
236 	init_waitqueue_entry(&wait, current);
237 	spin_lock_irqsave(&pool->lock, flags);
238 	if (pool->ptr == NULL) {	/* not initialized */
239 		snd_printd("seq: pool is not initialized\n");
240 		err = -EINVAL;
241 		goto __error;
242 	}
243 	while (pool->free == NULL && ! nonblock && ! pool->closing) {
244 
245 		set_current_state(TASK_INTERRUPTIBLE);
246 		add_wait_queue(&pool->output_sleep, &wait);
247 		spin_unlock_irq(&pool->lock);
248 		schedule();
249 		spin_lock_irq(&pool->lock);
250 		remove_wait_queue(&pool->output_sleep, &wait);
251 		/* interrupted? */
252 		if (signal_pending(current)) {
253 			err = -ERESTARTSYS;
254 			goto __error;
255 		}
256 	}
257 	if (pool->closing) { /* closing.. */
258 		err = -ENOMEM;
259 		goto __error;
260 	}
261 
262 	cell = pool->free;
263 	if (cell) {
264 		int used;
265 		pool->free = cell->next;
266 		atomic_inc(&pool->counter);
267 		used = atomic_read(&pool->counter);
268 		if (pool->max_used < used)
269 			pool->max_used = used;
270 		pool->event_alloc_success++;
271 		/* clear cell pointers */
272 		cell->next = NULL;
273 		err = 0;
274 	} else
275 		pool->event_alloc_failures++;
276 	*cellp = cell;
277 
278 __error:
279 	spin_unlock_irqrestore(&pool->lock, flags);
280 	return err;
281 }
282 
283 
284 /*
285  * duplicate the event to a cell.
286  * if the event has external data, the data is decomposed to additional
287  * cells.
288  */
snd_seq_event_dup(struct snd_seq_pool * pool,struct snd_seq_event * event,struct snd_seq_event_cell ** cellp,int nonblock,struct file * file)289 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
290 		      struct snd_seq_event_cell **cellp, int nonblock,
291 		      struct file *file)
292 {
293 	int ncells, err;
294 	unsigned int extlen;
295 	struct snd_seq_event_cell *cell;
296 
297 	*cellp = NULL;
298 
299 	ncells = 0;
300 	extlen = 0;
301 	if (snd_seq_ev_is_variable(event)) {
302 		extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
303 		ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
304 	}
305 	if (ncells >= pool->total_elements)
306 		return -ENOMEM;
307 
308 	err = snd_seq_cell_alloc(pool, &cell, nonblock, file);
309 	if (err < 0)
310 		return err;
311 
312 	/* copy the event */
313 	cell->event = *event;
314 
315 	/* decompose */
316 	if (snd_seq_ev_is_variable(event)) {
317 		int len = extlen;
318 		int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
319 		int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
320 		struct snd_seq_event_cell *src, *tmp, *tail;
321 		char *buf;
322 
323 		cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
324 		cell->event.data.ext.ptr = NULL;
325 
326 		src = (struct snd_seq_event_cell *)event->data.ext.ptr;
327 		buf = (char *)event->data.ext.ptr;
328 		tail = NULL;
329 
330 		while (ncells-- > 0) {
331 			int size = sizeof(struct snd_seq_event);
332 			if (len < size)
333 				size = len;
334 			err = snd_seq_cell_alloc(pool, &tmp, nonblock, file);
335 			if (err < 0)
336 				goto __error;
337 			if (cell->event.data.ext.ptr == NULL)
338 				cell->event.data.ext.ptr = tmp;
339 			if (tail)
340 				tail->next = tmp;
341 			tail = tmp;
342 			/* copy chunk */
343 			if (is_chained && src) {
344 				tmp->event = src->event;
345 				src = src->next;
346 			} else if (is_usrptr) {
347 				if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
348 					err = -EFAULT;
349 					goto __error;
350 				}
351 			} else {
352 				memcpy(&tmp->event, buf, size);
353 			}
354 			buf += size;
355 			len -= size;
356 		}
357 	}
358 
359 	*cellp = cell;
360 	return 0;
361 
362 __error:
363 	snd_seq_cell_free(cell);
364 	return err;
365 }
366 
367 
368 /* poll wait */
snd_seq_pool_poll_wait(struct snd_seq_pool * pool,struct file * file,poll_table * wait)369 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
370 			   poll_table *wait)
371 {
372 	poll_wait(file, &pool->output_sleep, wait);
373 	return snd_seq_output_ok(pool);
374 }
375 
376 
377 /* allocate room specified number of events */
snd_seq_pool_init(struct snd_seq_pool * pool)378 int snd_seq_pool_init(struct snd_seq_pool *pool)
379 {
380 	int cell;
381 	struct snd_seq_event_cell *cellptr;
382 	unsigned long flags;
383 
384 	if (snd_BUG_ON(!pool))
385 		return -EINVAL;
386 	if (pool->ptr)			/* should be atomic? */
387 		return 0;
388 
389 	pool->ptr = vmalloc(sizeof(struct snd_seq_event_cell) * pool->size);
390 	if (pool->ptr == NULL) {
391 		snd_printd("seq: malloc for sequencer events failed\n");
392 		return -ENOMEM;
393 	}
394 
395 	/* add new cells to the free cell list */
396 	spin_lock_irqsave(&pool->lock, flags);
397 	pool->free = NULL;
398 
399 	for (cell = 0; cell < pool->size; cell++) {
400 		cellptr = pool->ptr + cell;
401 		cellptr->pool = pool;
402 		cellptr->next = pool->free;
403 		pool->free = cellptr;
404 	}
405 	pool->room = (pool->size + 1) / 2;
406 
407 	/* init statistics */
408 	pool->max_used = 0;
409 	pool->total_elements = pool->size;
410 	spin_unlock_irqrestore(&pool->lock, flags);
411 	return 0;
412 }
413 
414 /* remove events */
snd_seq_pool_done(struct snd_seq_pool * pool)415 int snd_seq_pool_done(struct snd_seq_pool *pool)
416 {
417 	unsigned long flags;
418 	struct snd_seq_event_cell *ptr;
419 	int max_count = 5 * HZ;
420 
421 	if (snd_BUG_ON(!pool))
422 		return -EINVAL;
423 
424 	/* wait for closing all threads */
425 	spin_lock_irqsave(&pool->lock, flags);
426 	pool->closing = 1;
427 	spin_unlock_irqrestore(&pool->lock, flags);
428 
429 	if (waitqueue_active(&pool->output_sleep))
430 		wake_up(&pool->output_sleep);
431 
432 	while (atomic_read(&pool->counter) > 0) {
433 		if (max_count == 0) {
434 			snd_printk(KERN_WARNING "snd_seq_pool_done timeout: %d cells remain\n", atomic_read(&pool->counter));
435 			break;
436 		}
437 		schedule_timeout_uninterruptible(1);
438 		max_count--;
439 	}
440 
441 	/* release all resources */
442 	spin_lock_irqsave(&pool->lock, flags);
443 	ptr = pool->ptr;
444 	pool->ptr = NULL;
445 	pool->free = NULL;
446 	pool->total_elements = 0;
447 	spin_unlock_irqrestore(&pool->lock, flags);
448 
449 	vfree(ptr);
450 
451 	spin_lock_irqsave(&pool->lock, flags);
452 	pool->closing = 0;
453 	spin_unlock_irqrestore(&pool->lock, flags);
454 
455 	return 0;
456 }
457 
458 
459 /* init new memory pool */
snd_seq_pool_new(int poolsize)460 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
461 {
462 	struct snd_seq_pool *pool;
463 
464 	/* create pool block */
465 	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
466 	if (pool == NULL) {
467 		snd_printd("seq: malloc failed for pool\n");
468 		return NULL;
469 	}
470 	spin_lock_init(&pool->lock);
471 	pool->ptr = NULL;
472 	pool->free = NULL;
473 	pool->total_elements = 0;
474 	atomic_set(&pool->counter, 0);
475 	pool->closing = 0;
476 	init_waitqueue_head(&pool->output_sleep);
477 
478 	pool->size = poolsize;
479 
480 	/* init statistics */
481 	pool->max_used = 0;
482 	return pool;
483 }
484 
485 /* remove memory pool */
snd_seq_pool_delete(struct snd_seq_pool ** ppool)486 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
487 {
488 	struct snd_seq_pool *pool = *ppool;
489 
490 	*ppool = NULL;
491 	if (pool == NULL)
492 		return 0;
493 	snd_seq_pool_done(pool);
494 	kfree(pool);
495 	return 0;
496 }
497 
498 /* initialize sequencer memory */
snd_sequencer_memory_init(void)499 int __init snd_sequencer_memory_init(void)
500 {
501 	return 0;
502 }
503 
504 /* release sequencer memory */
snd_sequencer_memory_done(void)505 void __exit snd_sequencer_memory_done(void)
506 {
507 }
508 
509 
510 /* exported to seq_clientmgr.c */
snd_seq_info_pool(struct snd_info_buffer * buffer,struct snd_seq_pool * pool,char * space)511 void snd_seq_info_pool(struct snd_info_buffer *buffer,
512 		       struct snd_seq_pool *pool, char *space)
513 {
514 	if (pool == NULL)
515 		return;
516 	snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
517 	snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
518 	snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
519 	snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
520 	snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
521 }
522