1 // SPDX-License-Identifier: GPL-2.0-or-later
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>
9 #include <linux/init.h>
10 #include <linux/export.h>
11 #include <linux/slab.h>
12 #include <linux/sched/signal.h>
14 #include <sound/core.h>
16 #include <sound/seq_kernel.h>
17 #include "seq_memory.h"
18 #include "seq_queue.h"
22 static inline int snd_seq_pool_available(struct snd_seq_pool *pool)
24 return pool->total_elements - atomic_read(&pool->counter);
27 static inline int snd_seq_output_ok(struct snd_seq_pool *pool)
29 return snd_seq_pool_available(pool) >= pool->room;
33 * Variable length event:
34 * The event like sysex uses variable length type.
35 * The external data may be stored in three different formats.
37 * This is the normal case.
38 * ext.data.len = length
39 * ext.data.ptr = buffer pointer
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
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 -> ..
55 * call dump function to expand external data.
58 static int get_var_len(const struct snd_seq_event *event)
60 if ((event->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
63 return event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
66 int snd_seq_dump_var_event(const struct snd_seq_event *event,
67 snd_seq_dump_func_t func, void *private_data)
70 struct snd_seq_event_cell *cell;
72 if ((len = get_var_len(event)) <= 0)
75 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
77 char __user *curptr = (char __force __user *)event->data.ext.ptr;
79 int size = sizeof(buf);
82 if (copy_from_user(buf, curptr, size))
84 err = func(private_data, buf, size);
92 if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
93 return func(private_data, event->data.ext.ptr, len);
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);
100 err = func(private_data, &cell->event, size);
107 EXPORT_SYMBOL(snd_seq_dump_var_event);
112 * expand the variable length event to linear buffer space.
115 static int seq_copy_in_kernel(char **bufptr, const void *src, int size)
117 memcpy(*bufptr, src, size);
122 static int seq_copy_in_user(char __user **bufptr, const void *src, int size)
124 if (copy_to_user(*bufptr, src, size))
130 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
131 int in_kernel, int size_aligned)
136 if ((len = get_var_len(event)) < 0)
139 if (size_aligned > 0)
140 newlen = roundup(len, size_aligned);
144 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
147 if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
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,
155 return err < 0 ? err : newlen;
157 EXPORT_SYMBOL(snd_seq_expand_var_event);
160 * release this cell, free extended data if available
163 static inline void free_cell(struct snd_seq_pool *pool,
164 struct snd_seq_event_cell *cell)
166 cell->next = pool->free;
168 atomic_dec(&pool->counter);
171 void snd_seq_cell_free(struct snd_seq_event_cell * cell)
174 struct snd_seq_pool *pool;
176 if (snd_BUG_ON(!cell))
179 if (snd_BUG_ON(!pool))
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);
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);
200 spin_unlock_irqrestore(&pool->lock, flags);
205 * allocate an event cell.
207 static 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)
212 struct snd_seq_event_cell *cell;
215 wait_queue_entry_t wait;
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");
229 while (pool->free == NULL && ! nonblock && ! pool->closing) {
231 set_current_state(TASK_INTERRUPTIBLE);
232 add_wait_queue(&pool->output_sleep, &wait);
233 spin_unlock_irqrestore(&pool->lock, flags);
235 mutex_unlock(mutexp);
239 spin_lock_irqsave(&pool->lock, flags);
240 remove_wait_queue(&pool->output_sleep, &wait);
242 if (signal_pending(current)) {
247 if (pool->closing) { /* closing.. */
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 */
265 pool->event_alloc_failures++;
269 spin_unlock_irqrestore(&pool->lock, flags);
275 * duplicate the event to a cell.
276 * if the event has external data, the data is decomposed to additional
279 int 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)
285 struct snd_seq_event_cell *cell;
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);
295 if (ncells >= pool->total_elements)
298 err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
303 cell->event = *event;
306 if (snd_seq_ev_is_variable(event)) {
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;
313 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
314 cell->event.data.ext.ptr = NULL;
316 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
317 buf = (char *)event->data.ext.ptr;
320 while (ncells-- > 0) {
321 int size = sizeof(struct snd_seq_event);
324 err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
328 if (cell->event.data.ext.ptr == NULL)
329 cell->event.data.ext.ptr = tmp;
334 if (is_chained && src) {
335 tmp->event = src->event;
337 } else if (is_usrptr) {
338 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
343 memcpy(&tmp->event, buf, size);
354 snd_seq_cell_free(cell);
360 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
363 poll_wait(file, &pool->output_sleep, wait);
364 return snd_seq_output_ok(pool);
368 /* allocate room specified number of events */
369 int snd_seq_pool_init(struct snd_seq_pool *pool)
372 struct snd_seq_event_cell *cellptr;
374 if (snd_BUG_ON(!pool))
377 cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
382 /* add new cells to the free cell list */
383 spin_lock_irq(&pool->lock);
385 spin_unlock_irq(&pool->lock);
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;
399 pool->room = (pool->size + 1) / 2;
401 /* init statistics */
403 pool->total_elements = pool->size;
404 spin_unlock_irq(&pool->lock);
408 /* refuse the further insertion to the pool */
409 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
413 if (snd_BUG_ON(!pool))
415 spin_lock_irqsave(&pool->lock, flags);
417 spin_unlock_irqrestore(&pool->lock, flags);
421 int snd_seq_pool_done(struct snd_seq_pool *pool)
423 struct snd_seq_event_cell *ptr;
425 if (snd_BUG_ON(!pool))
428 /* wait for closing all threads */
429 if (waitqueue_active(&pool->output_sleep))
430 wake_up(&pool->output_sleep);
432 while (atomic_read(&pool->counter) > 0)
433 schedule_timeout_uninterruptible(1);
435 /* release all resources */
436 spin_lock_irq(&pool->lock);
440 pool->total_elements = 0;
441 spin_unlock_irq(&pool->lock);
445 spin_lock_irq(&pool->lock);
447 spin_unlock_irq(&pool->lock);
453 /* init new memory pool */
454 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
456 struct snd_seq_pool *pool;
458 /* create pool block */
459 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
462 spin_lock_init(&pool->lock);
465 pool->total_elements = 0;
466 atomic_set(&pool->counter, 0);
468 init_waitqueue_head(&pool->output_sleep);
470 pool->size = poolsize;
472 /* init statistics */
477 /* remove memory pool */
478 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
480 struct snd_seq_pool *pool = *ppool;
485 snd_seq_pool_mark_closing(pool);
486 snd_seq_pool_done(pool);
491 /* exported to seq_clientmgr.c */
492 void snd_seq_info_pool(struct snd_info_buffer *buffer,
493 struct snd_seq_pool *pool, char *space)
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);