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v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  ALSA sequencer Memory Manager
  4 *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
  5 *                        Jaroslav Kysela <perex@perex.cz>
  6 *                2000 by Takashi Iwai <tiwai@suse.de>
  7 */
  8
  9#include <linux/init.h>
 10#include <linux/export.h>
 11#include <linux/slab.h>
 12#include <linux/sched/signal.h>
 13#include <linux/mm.h>
 14#include <sound/core.h>
 15
 16#include <sound/seq_kernel.h>
 17#include "seq_memory.h"
 18#include "seq_queue.h"
 19#include "seq_info.h"
 20#include "seq_lock.h"
 21
 22static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
 23{
 24	return pool->total_elements - atomic_read(&pool->counter);
 25}
 26
 27static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
 28{
 29	return snd_seq_pool_available(pool) >= pool->room;
 30}
 31
 32/*
 33 * Variable length event:
 34 * The event like sysex uses variable length type.
 35 * The external data may be stored in three different formats.
 36 * 1) kernel space
 37 *    This is the normal case.
 38 *      ext.data.len = length
 39 *      ext.data.ptr = buffer pointer
 40 * 2) user space
 41 *    When an event is generated via read(), the external data is
 42 *    kept in user space until expanded.
 43 *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
 44 *      ext.data.ptr = userspace pointer
 45 * 3) chained cells
 46 *    When the variable length event is enqueued (in prioq or fifo),
 47 *    the external data is decomposed to several cells.
 48 *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
 49 *      ext.data.ptr = the additiona cell head
 50 *         -> cell.next -> cell.next -> ..
 51 */
 52
 53/*
 54 * exported:
 55 * call dump function to expand external data.
 56 */
 57
 58static int get_var_len(const struct snd_seq_event *event)
 59{
 60	if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
 61		return -EINVAL;
 62
 63	return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
 64}
 65
 66int snd_seq_dump_var_event(const struct snd_seq_event *event,
 67			   snd_seq_dump_func_t func, void *private_data)
 68{
 69	int len, err;
 70	struct snd_seq_event_cell *cell;
 71
 72	if ((len = get_var_len(event)) <= 0)
 
 73		return len;
 74
 75	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
 76		char buf[32];
 77		char __user *curptr = (char __force __user *)event->data.ext.ptr;
 78		while (len > 0) {
 79			int size = sizeof(buf);
 80			if (len < size)
 81				size = len;
 82			if (copy_from_user(buf, curptr, size))
 83				return -EFAULT;
 84			err = func(private_data, buf, size);
 85			if (err < 0)
 86				return err;
 87			curptr += size;
 88			len -= size;
 89		}
 90		return 0;
 91	}
 92	if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
 93		return func(private_data, event->data.ext.ptr, len);
 94
 95	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
 96	for (; len > 0 && cell; cell = cell->next) {
 97		int size = sizeof(struct snd_seq_event);
 98		if (len < size)
 99			size = len;
100		err = func(private_data, &cell->event, size);
101		if (err < 0)
102			return err;
103		len -= size;
104	}
105	return 0;
106}
107EXPORT_SYMBOL(snd_seq_dump_var_event);
108
109
110/*
111 * exported:
112 * expand the variable length event to linear buffer space.
113 */
114
115static int seq_copy_in_kernel(char **bufptr, const void *src, int size)
116{
 
 
117	memcpy(*bufptr, src, size);
118	*bufptr += size;
119	return 0;
120}
121
122static int seq_copy_in_user(char __user **bufptr, const void *src, int size)
123{
 
 
124	if (copy_to_user(*bufptr, src, size))
125		return -EFAULT;
126	*bufptr += size;
127	return 0;
128}
129
130int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
131			     int in_kernel, int size_aligned)
132{
133	int len, newlen;
134	int err;
135
136	if ((len = get_var_len(event)) < 0)
 
137		return len;
138	newlen = len;
139	if (size_aligned > 0)
140		newlen = roundup(len, size_aligned);
141	if (count < newlen)
142		return -EAGAIN;
143
144	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
145		if (! in_kernel)
146			return -EINVAL;
147		if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
148			return -EFAULT;
149		return newlen;
150	}
151	err = snd_seq_dump_var_event(event,
152				     in_kernel ? (snd_seq_dump_func_t)seq_copy_in_kernel :
153				     (snd_seq_dump_func_t)seq_copy_in_user,
154				     &buf);
155	return err < 0 ? err : newlen;
156}
157EXPORT_SYMBOL(snd_seq_expand_var_event);
158
159/*
160 * release this cell, free extended data if available
161 */
162
163static inline void free_cell(struct snd_seq_pool *pool,
164			     struct snd_seq_event_cell *cell)
165{
166	cell->next = pool->free;
167	pool->free = cell;
168	atomic_dec(&pool->counter);
169}
170
171void snd_seq_cell_free(struct snd_seq_event_cell * cell)
172{
173	unsigned long flags;
174	struct snd_seq_pool *pool;
175
176	if (snd_BUG_ON(!cell))
177		return;
178	pool = cell->pool;
179	if (snd_BUG_ON(!pool))
180		return;
181
182	spin_lock_irqsave(&pool->lock, flags);
183	free_cell(pool, cell);
184	if (snd_seq_ev_is_variable(&cell->event)) {
185		if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
186			struct snd_seq_event_cell *curp, *nextptr;
187			curp = cell->event.data.ext.ptr;
188			for (; curp; curp = nextptr) {
189				nextptr = curp->next;
190				curp->next = pool->free;
191				free_cell(pool, curp);
192			}
193		}
194	}
195	if (waitqueue_active(&pool->output_sleep)) {
196		/* has enough space now? */
197		if (snd_seq_output_ok(pool))
198			wake_up(&pool->output_sleep);
199	}
200	spin_unlock_irqrestore(&pool->lock, flags);
201}
202
203
204/*
205 * allocate an event cell.
206 */
207static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
208			      struct snd_seq_event_cell **cellp,
209			      int nonblock, struct file *file,
210			      struct mutex *mutexp)
211{
212	struct snd_seq_event_cell *cell;
213	unsigned long flags;
214	int err = -EAGAIN;
215	wait_queue_entry_t wait;
216
217	if (pool == NULL)
218		return -EINVAL;
219
220	*cellp = NULL;
221
222	init_waitqueue_entry(&wait, current);
223	spin_lock_irqsave(&pool->lock, flags);
224	if (pool->ptr == NULL) {	/* not initialized */
225		pr_debug("ALSA: seq: pool is not initialized\n");
226		err = -EINVAL;
227		goto __error;
228	}
229	while (pool->free == NULL && ! nonblock && ! pool->closing) {
230
231		set_current_state(TASK_INTERRUPTIBLE);
232		add_wait_queue(&pool->output_sleep, &wait);
233		spin_unlock_irqrestore(&pool->lock, flags);
234		if (mutexp)
235			mutex_unlock(mutexp);
236		schedule();
237		if (mutexp)
238			mutex_lock(mutexp);
239		spin_lock_irqsave(&pool->lock, flags);
240		remove_wait_queue(&pool->output_sleep, &wait);
241		/* interrupted? */
242		if (signal_pending(current)) {
243			err = -ERESTARTSYS;
244			goto __error;
245		}
246	}
247	if (pool->closing) { /* closing.. */
248		err = -ENOMEM;
249		goto __error;
250	}
251
252	cell = pool->free;
253	if (cell) {
254		int used;
255		pool->free = cell->next;
256		atomic_inc(&pool->counter);
257		used = atomic_read(&pool->counter);
258		if (pool->max_used < used)
259			pool->max_used = used;
260		pool->event_alloc_success++;
261		/* clear cell pointers */
262		cell->next = NULL;
263		err = 0;
264	} else
265		pool->event_alloc_failures++;
266	*cellp = cell;
267
268__error:
269	spin_unlock_irqrestore(&pool->lock, flags);
270	return err;
271}
272
273
274/*
275 * duplicate the event to a cell.
276 * if the event has external data, the data is decomposed to additional
277 * cells.
278 */
279int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
280		      struct snd_seq_event_cell **cellp, int nonblock,
281		      struct file *file, struct mutex *mutexp)
282{
283	int ncells, err;
284	unsigned int extlen;
285	struct snd_seq_event_cell *cell;
286
287	*cellp = NULL;
288
289	ncells = 0;
290	extlen = 0;
291	if (snd_seq_ev_is_variable(event)) {
292		extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
293		ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
294	}
295	if (ncells >= pool->total_elements)
296		return -ENOMEM;
297
298	err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
299	if (err < 0)
300		return err;
301
302	/* copy the event */
303	cell->event = *event;
304
305	/* decompose */
306	if (snd_seq_ev_is_variable(event)) {
307		int len = extlen;
308		int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
309		int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
310		struct snd_seq_event_cell *src, *tmp, *tail;
311		char *buf;
312
313		cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
314		cell->event.data.ext.ptr = NULL;
315
316		src = (struct snd_seq_event_cell *)event->data.ext.ptr;
317		buf = (char *)event->data.ext.ptr;
318		tail = NULL;
319
320		while (ncells-- > 0) {
321			int size = sizeof(struct snd_seq_event);
322			if (len < size)
323				size = len;
324			err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
325						 mutexp);
326			if (err < 0)
327				goto __error;
328			if (cell->event.data.ext.ptr == NULL)
329				cell->event.data.ext.ptr = tmp;
330			if (tail)
331				tail->next = tmp;
332			tail = tmp;
333			/* copy chunk */
334			if (is_chained && src) {
335				tmp->event = src->event;
336				src = src->next;
337			} else if (is_usrptr) {
338				if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
339					err = -EFAULT;
340					goto __error;
341				}
342			} else {
343				memcpy(&tmp->event, buf, size);
344			}
345			buf += size;
346			len -= size;
347		}
348	}
349
350	*cellp = cell;
351	return 0;
352
353__error:
354	snd_seq_cell_free(cell);
355	return err;
356}
357  
358
359/* poll wait */
360int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
361			   poll_table *wait)
362{
363	poll_wait(file, &pool->output_sleep, wait);
364	return snd_seq_output_ok(pool);
365}
366
367
368/* allocate room specified number of events */
369int snd_seq_pool_init(struct snd_seq_pool *pool)
370{
371	int cell;
372	struct snd_seq_event_cell *cellptr;
373
374	if (snd_BUG_ON(!pool))
375		return -EINVAL;
376
377	cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
378				 GFP_KERNEL);
379	if (!cellptr)
380		return -ENOMEM;
381
382	/* add new cells to the free cell list */
383	spin_lock_irq(&pool->lock);
384	if (pool->ptr) {
385		spin_unlock_irq(&pool->lock);
386		kvfree(cellptr);
387		return 0;
388	}
389
390	pool->ptr = cellptr;
391	pool->free = NULL;
392
393	for (cell = 0; cell < pool->size; cell++) {
394		cellptr = pool->ptr + cell;
395		cellptr->pool = pool;
396		cellptr->next = pool->free;
397		pool->free = cellptr;
398	}
399	pool->room = (pool->size + 1) / 2;
400
401	/* init statistics */
402	pool->max_used = 0;
403	pool->total_elements = pool->size;
404	spin_unlock_irq(&pool->lock);
405	return 0;
406}
407
408/* refuse the further insertion to the pool */
409void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
410{
411	unsigned long flags;
412
413	if (snd_BUG_ON(!pool))
414		return;
415	spin_lock_irqsave(&pool->lock, flags);
416	pool->closing = 1;
417	spin_unlock_irqrestore(&pool->lock, flags);
418}
419
420/* remove events */
421int snd_seq_pool_done(struct snd_seq_pool *pool)
422{
423	struct snd_seq_event_cell *ptr;
424
425	if (snd_BUG_ON(!pool))
426		return -EINVAL;
427
428	/* wait for closing all threads */
429	if (waitqueue_active(&pool->output_sleep))
430		wake_up(&pool->output_sleep);
431
432	while (atomic_read(&pool->counter) > 0)
433		schedule_timeout_uninterruptible(1);
434	
435	/* release all resources */
436	spin_lock_irq(&pool->lock);
437	ptr = pool->ptr;
438	pool->ptr = NULL;
439	pool->free = NULL;
440	pool->total_elements = 0;
441	spin_unlock_irq(&pool->lock);
442
443	kvfree(ptr);
444
445	spin_lock_irq(&pool->lock);
446	pool->closing = 0;
447	spin_unlock_irq(&pool->lock);
448
449	return 0;
450}
451
452
453/* init new memory pool */
454struct snd_seq_pool *snd_seq_pool_new(int poolsize)
455{
456	struct snd_seq_pool *pool;
457
458	/* create pool block */
459	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
460	if (!pool)
461		return NULL;
462	spin_lock_init(&pool->lock);
463	pool->ptr = NULL;
464	pool->free = NULL;
465	pool->total_elements = 0;
466	atomic_set(&pool->counter, 0);
467	pool->closing = 0;
468	init_waitqueue_head(&pool->output_sleep);
469	
470	pool->size = poolsize;
471
472	/* init statistics */
473	pool->max_used = 0;
474	return pool;
475}
476
477/* remove memory pool */
478int snd_seq_pool_delete(struct snd_seq_pool **ppool)
479{
480	struct snd_seq_pool *pool = *ppool;
481
482	*ppool = NULL;
483	if (pool == NULL)
484		return 0;
485	snd_seq_pool_mark_closing(pool);
486	snd_seq_pool_done(pool);
487	kfree(pool);
488	return 0;
489}
490
491/* exported to seq_clientmgr.c */
492void snd_seq_info_pool(struct snd_info_buffer *buffer,
493		       struct snd_seq_pool *pool, char *space)
494{
495	if (pool == NULL)
496		return;
497	snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
498	snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
499	snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
500	snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
501	snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
502}
v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  ALSA sequencer Memory Manager
  4 *  Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
  5 *                        Jaroslav Kysela <perex@perex.cz>
  6 *                2000 by Takashi Iwai <tiwai@suse.de>
  7 */
  8
  9#include <linux/init.h>
 10#include <linux/export.h>
 11#include <linux/slab.h>
 12#include <linux/sched/signal.h>
 13#include <linux/mm.h>
 14#include <sound/core.h>
 15
 16#include <sound/seq_kernel.h>
 17#include "seq_memory.h"
 18#include "seq_queue.h"
 19#include "seq_info.h"
 20#include "seq_lock.h"
 21
 22static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
 23{
 24	return pool->total_elements - atomic_read(&pool->counter);
 25}
 26
 27static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
 28{
 29	return snd_seq_pool_available(pool) >= pool->room;
 30}
 31
 32/*
 33 * Variable length event:
 34 * The event like sysex uses variable length type.
 35 * The external data may be stored in three different formats.
 36 * 1) kernel space
 37 *    This is the normal case.
 38 *      ext.data.len = length
 39 *      ext.data.ptr = buffer pointer
 40 * 2) user space
 41 *    When an event is generated via read(), the external data is
 42 *    kept in user space until expanded.
 43 *      ext.data.len = length | SNDRV_SEQ_EXT_USRPTR
 44 *      ext.data.ptr = userspace pointer
 45 * 3) chained cells
 46 *    When the variable length event is enqueued (in prioq or fifo),
 47 *    the external data is decomposed to several cells.
 48 *      ext.data.len = length | SNDRV_SEQ_EXT_CHAINED
 49 *      ext.data.ptr = the additiona cell head
 50 *         -> cell.next -> cell.next -> ..
 51 */
 52
 53/*
 54 * exported:
 55 * call dump function to expand external data.
 56 */
 57
 58static int get_var_len(const struct snd_seq_event *event)
 59{
 60	if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
 61		return -EINVAL;
 62
 63	return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
 64}
 65
 66int snd_seq_dump_var_event(const struct snd_seq_event *event,
 67			   snd_seq_dump_func_t func, void *private_data)
 68{
 69	int len, err;
 70	struct snd_seq_event_cell *cell;
 71
 72	len = get_var_len(event);
 73	if (len <= 0)
 74		return len;
 75
 76	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
 77		char buf[32];
 78		char __user *curptr = (char __force __user *)event->data.ext.ptr;
 79		while (len > 0) {
 80			int size = sizeof(buf);
 81			if (len < size)
 82				size = len;
 83			if (copy_from_user(buf, curptr, size))
 84				return -EFAULT;
 85			err = func(private_data, buf, size);
 86			if (err < 0)
 87				return err;
 88			curptr += size;
 89			len -= size;
 90		}
 91		return 0;
 92	}
 93	if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
 94		return func(private_data, event->data.ext.ptr, len);
 95
 96	cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
 97	for (; len > 0 && cell; cell = cell->next) {
 98		int size = sizeof(struct snd_seq_event);
 99		if (len < size)
100			size = len;
101		err = func(private_data, &cell->event, size);
102		if (err < 0)
103			return err;
104		len -= size;
105	}
106	return 0;
107}
108EXPORT_SYMBOL(snd_seq_dump_var_event);
109
110
111/*
112 * exported:
113 * expand the variable length event to linear buffer space.
114 */
115
116static int seq_copy_in_kernel(void *ptr, void *src, int size)
117{
118	char **bufptr = ptr;
119
120	memcpy(*bufptr, src, size);
121	*bufptr += size;
122	return 0;
123}
124
125static int seq_copy_in_user(void *ptr, void *src, int size)
126{
127	char __user **bufptr = ptr;
128
129	if (copy_to_user(*bufptr, src, size))
130		return -EFAULT;
131	*bufptr += size;
132	return 0;
133}
134
135int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
136			     int in_kernel, int size_aligned)
137{
138	int len, newlen;
139	int err;
140
141	len = get_var_len(event);
142	if (len < 0)
143		return len;
144	newlen = len;
145	if (size_aligned > 0)
146		newlen = roundup(len, size_aligned);
147	if (count < newlen)
148		return -EAGAIN;
149
150	if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
151		if (! in_kernel)
152			return -EINVAL;
153		if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
154			return -EFAULT;
155		return newlen;
156	}
157	err = snd_seq_dump_var_event(event,
158				     in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
 
159				     &buf);
160	return err < 0 ? err : newlen;
161}
162EXPORT_SYMBOL(snd_seq_expand_var_event);
163
164/*
165 * release this cell, free extended data if available
166 */
167
168static inline void free_cell(struct snd_seq_pool *pool,
169			     struct snd_seq_event_cell *cell)
170{
171	cell->next = pool->free;
172	pool->free = cell;
173	atomic_dec(&pool->counter);
174}
175
176void snd_seq_cell_free(struct snd_seq_event_cell * cell)
177{
178	unsigned long flags;
179	struct snd_seq_pool *pool;
180
181	if (snd_BUG_ON(!cell))
182		return;
183	pool = cell->pool;
184	if (snd_BUG_ON(!pool))
185		return;
186
187	spin_lock_irqsave(&pool->lock, flags);
188	free_cell(pool, cell);
189	if (snd_seq_ev_is_variable(&cell->event)) {
190		if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
191			struct snd_seq_event_cell *curp, *nextptr;
192			curp = cell->event.data.ext.ptr;
193			for (; curp; curp = nextptr) {
194				nextptr = curp->next;
195				curp->next = pool->free;
196				free_cell(pool, curp);
197			}
198		}
199	}
200	if (waitqueue_active(&pool->output_sleep)) {
201		/* has enough space now? */
202		if (snd_seq_output_ok(pool))
203			wake_up(&pool->output_sleep);
204	}
205	spin_unlock_irqrestore(&pool->lock, flags);
206}
207
208
209/*
210 * allocate an event cell.
211 */
212static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
213			      struct snd_seq_event_cell **cellp,
214			      int nonblock, struct file *file,
215			      struct mutex *mutexp)
216{
217	struct snd_seq_event_cell *cell;
218	unsigned long flags;
219	int err = -EAGAIN;
220	wait_queue_entry_t wait;
221
222	if (pool == NULL)
223		return -EINVAL;
224
225	*cellp = NULL;
226
227	init_waitqueue_entry(&wait, current);
228	spin_lock_irqsave(&pool->lock, flags);
229	if (pool->ptr == NULL) {	/* not initialized */
230		pr_debug("ALSA: seq: pool is not initialized\n");
231		err = -EINVAL;
232		goto __error;
233	}
234	while (pool->free == NULL && ! nonblock && ! pool->closing) {
235
236		set_current_state(TASK_INTERRUPTIBLE);
237		add_wait_queue(&pool->output_sleep, &wait);
238		spin_unlock_irqrestore(&pool->lock, flags);
239		if (mutexp)
240			mutex_unlock(mutexp);
241		schedule();
242		if (mutexp)
243			mutex_lock(mutexp);
244		spin_lock_irqsave(&pool->lock, flags);
245		remove_wait_queue(&pool->output_sleep, &wait);
246		/* interrupted? */
247		if (signal_pending(current)) {
248			err = -ERESTARTSYS;
249			goto __error;
250		}
251	}
252	if (pool->closing) { /* closing.. */
253		err = -ENOMEM;
254		goto __error;
255	}
256
257	cell = pool->free;
258	if (cell) {
259		int used;
260		pool->free = cell->next;
261		atomic_inc(&pool->counter);
262		used = atomic_read(&pool->counter);
263		if (pool->max_used < used)
264			pool->max_used = used;
265		pool->event_alloc_success++;
266		/* clear cell pointers */
267		cell->next = NULL;
268		err = 0;
269	} else
270		pool->event_alloc_failures++;
271	*cellp = cell;
272
273__error:
274	spin_unlock_irqrestore(&pool->lock, flags);
275	return err;
276}
277
278
279/*
280 * duplicate the event to a cell.
281 * if the event has external data, the data is decomposed to additional
282 * cells.
283 */
284int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
285		      struct snd_seq_event_cell **cellp, int nonblock,
286		      struct file *file, struct mutex *mutexp)
287{
288	int ncells, err;
289	unsigned int extlen;
290	struct snd_seq_event_cell *cell;
291
292	*cellp = NULL;
293
294	ncells = 0;
295	extlen = 0;
296	if (snd_seq_ev_is_variable(event)) {
297		extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
298		ncells = DIV_ROUND_UP(extlen, sizeof(struct snd_seq_event));
299	}
300	if (ncells >= pool->total_elements)
301		return -ENOMEM;
302
303	err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
304	if (err < 0)
305		return err;
306
307	/* copy the event */
308	cell->event = *event;
309
310	/* decompose */
311	if (snd_seq_ev_is_variable(event)) {
312		int len = extlen;
313		int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
314		int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
315		struct snd_seq_event_cell *src, *tmp, *tail;
316		char *buf;
317
318		cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
319		cell->event.data.ext.ptr = NULL;
320
321		src = (struct snd_seq_event_cell *)event->data.ext.ptr;
322		buf = (char *)event->data.ext.ptr;
323		tail = NULL;
324
325		while (ncells-- > 0) {
326			int size = sizeof(struct snd_seq_event);
327			if (len < size)
328				size = len;
329			err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
330						 mutexp);
331			if (err < 0)
332				goto __error;
333			if (cell->event.data.ext.ptr == NULL)
334				cell->event.data.ext.ptr = tmp;
335			if (tail)
336				tail->next = tmp;
337			tail = tmp;
338			/* copy chunk */
339			if (is_chained && src) {
340				tmp->event = src->event;
341				src = src->next;
342			} else if (is_usrptr) {
343				if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
344					err = -EFAULT;
345					goto __error;
346				}
347			} else {
348				memcpy(&tmp->event, buf, size);
349			}
350			buf += size;
351			len -= size;
352		}
353	}
354
355	*cellp = cell;
356	return 0;
357
358__error:
359	snd_seq_cell_free(cell);
360	return err;
361}
362  
363
364/* poll wait */
365int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
366			   poll_table *wait)
367{
368	poll_wait(file, &pool->output_sleep, wait);
369	return snd_seq_output_ok(pool);
370}
371
372
373/* allocate room specified number of events */
374int snd_seq_pool_init(struct snd_seq_pool *pool)
375{
376	int cell;
377	struct snd_seq_event_cell *cellptr;
378
379	if (snd_BUG_ON(!pool))
380		return -EINVAL;
381
382	cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
383				 GFP_KERNEL);
384	if (!cellptr)
385		return -ENOMEM;
386
387	/* add new cells to the free cell list */
388	spin_lock_irq(&pool->lock);
389	if (pool->ptr) {
390		spin_unlock_irq(&pool->lock);
391		kvfree(cellptr);
392		return 0;
393	}
394
395	pool->ptr = cellptr;
396	pool->free = NULL;
397
398	for (cell = 0; cell < pool->size; cell++) {
399		cellptr = pool->ptr + cell;
400		cellptr->pool = pool;
401		cellptr->next = pool->free;
402		pool->free = cellptr;
403	}
404	pool->room = (pool->size + 1) / 2;
405
406	/* init statistics */
407	pool->max_used = 0;
408	pool->total_elements = pool->size;
409	spin_unlock_irq(&pool->lock);
410	return 0;
411}
412
413/* refuse the further insertion to the pool */
414void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
415{
416	unsigned long flags;
417
418	if (snd_BUG_ON(!pool))
419		return;
420	spin_lock_irqsave(&pool->lock, flags);
421	pool->closing = 1;
422	spin_unlock_irqrestore(&pool->lock, flags);
423}
424
425/* remove events */
426int snd_seq_pool_done(struct snd_seq_pool *pool)
427{
428	struct snd_seq_event_cell *ptr;
429
430	if (snd_BUG_ON(!pool))
431		return -EINVAL;
432
433	/* wait for closing all threads */
434	if (waitqueue_active(&pool->output_sleep))
435		wake_up(&pool->output_sleep);
436
437	while (atomic_read(&pool->counter) > 0)
438		schedule_timeout_uninterruptible(1);
439	
440	/* release all resources */
441	spin_lock_irq(&pool->lock);
442	ptr = pool->ptr;
443	pool->ptr = NULL;
444	pool->free = NULL;
445	pool->total_elements = 0;
446	spin_unlock_irq(&pool->lock);
447
448	kvfree(ptr);
449
450	spin_lock_irq(&pool->lock);
451	pool->closing = 0;
452	spin_unlock_irq(&pool->lock);
453
454	return 0;
455}
456
457
458/* init new memory pool */
459struct snd_seq_pool *snd_seq_pool_new(int poolsize)
460{
461	struct snd_seq_pool *pool;
462
463	/* create pool block */
464	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
465	if (!pool)
466		return NULL;
467	spin_lock_init(&pool->lock);
468	pool->ptr = NULL;
469	pool->free = NULL;
470	pool->total_elements = 0;
471	atomic_set(&pool->counter, 0);
472	pool->closing = 0;
473	init_waitqueue_head(&pool->output_sleep);
474	
475	pool->size = poolsize;
476
477	/* init statistics */
478	pool->max_used = 0;
479	return pool;
480}
481
482/* remove memory pool */
483int snd_seq_pool_delete(struct snd_seq_pool **ppool)
484{
485	struct snd_seq_pool *pool = *ppool;
486
487	*ppool = NULL;
488	if (pool == NULL)
489		return 0;
490	snd_seq_pool_mark_closing(pool);
491	snd_seq_pool_done(pool);
492	kfree(pool);
493	return 0;
494}
495
496/* exported to seq_clientmgr.c */
497void snd_seq_info_pool(struct snd_info_buffer *buffer,
498		       struct snd_seq_pool *pool, char *space)
499{
500	if (pool == NULL)
501		return;
502	snd_iprintf(buffer, "%sPool size          : %d\n", space, pool->total_elements);
503	snd_iprintf(buffer, "%sCells in use       : %d\n", space, atomic_read(&pool->counter));
504	snd_iprintf(buffer, "%sPeak cells in use  : %d\n", space, pool->max_used);
505	snd_iprintf(buffer, "%sAlloc success      : %d\n", space, pool->event_alloc_success);
506	snd_iprintf(buffer, "%sAlloc failures     : %d\n", space, pool->event_alloc_failures);
507}