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 static int dump_var_event(const struct snd_seq_event *event,
67 snd_seq_dump_func_t func, void *private_data,
68 int offset, int maxlen)
71 struct snd_seq_event_cell *cell;
73 len = get_var_len(event);
78 if (maxlen && len > offset + maxlen)
79 len = offset + maxlen;
81 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
83 char __user *curptr = (char __force __user *)event->data.ext.ptr;
87 int size = sizeof(buf);
90 if (copy_from_user(buf, curptr, size))
92 err = func(private_data, buf, size);
100 if (!(event->data.ext.len & SNDRV_SEQ_EXT_CHAINED))
101 return func(private_data, event->data.ext.ptr + offset,
104 cell = (struct snd_seq_event_cell *)event->data.ext.ptr;
105 for (; len > 0 && cell; cell = cell->next) {
106 int size = sizeof(struct snd_seq_event);
107 char *curptr = (char *)&cell->event;
109 if (offset >= size) {
116 err = func(private_data, curptr + offset, size - offset);
125 int snd_seq_dump_var_event(const struct snd_seq_event *event,
126 snd_seq_dump_func_t func, void *private_data)
128 return dump_var_event(event, func, private_data, 0, 0);
130 EXPORT_SYMBOL(snd_seq_dump_var_event);
135 * expand the variable length event to linear buffer space.
138 static int seq_copy_in_kernel(void *ptr, void *src, int size)
142 memcpy(*bufptr, src, size);
147 static int seq_copy_in_user(void *ptr, void *src, int size)
149 char __user **bufptr = ptr;
151 if (copy_to_user(*bufptr, src, size))
157 static int expand_var_event(const struct snd_seq_event *event,
158 int offset, int size, char *buf, bool in_kernel)
160 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
163 if (copy_from_user(buf,
164 (char __force __user *)event->data.ext.ptr + offset,
169 return dump_var_event(event,
170 in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
174 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
175 int in_kernel, int size_aligned)
177 int len, newlen, err;
179 len = get_var_len(event);
183 if (size_aligned > 0)
184 newlen = roundup(len, size_aligned);
187 err = expand_var_event(event, 0, len, buf, in_kernel);
192 memset(buf + len, 0, newlen - len);
193 else if (clear_user((__force void __user *)buf + len,
199 EXPORT_SYMBOL(snd_seq_expand_var_event);
201 int snd_seq_expand_var_event_at(const struct snd_seq_event *event, int count,
202 char *buf, int offset)
206 len = get_var_len(event);
214 err = expand_var_event(event, offset, count, buf, true);
219 EXPORT_SYMBOL_GPL(snd_seq_expand_var_event_at);
222 * release this cell, free extended data if available
225 static inline void free_cell(struct snd_seq_pool *pool,
226 struct snd_seq_event_cell *cell)
228 cell->next = pool->free;
230 atomic_dec(&pool->counter);
233 void snd_seq_cell_free(struct snd_seq_event_cell * cell)
236 struct snd_seq_pool *pool;
238 if (snd_BUG_ON(!cell))
241 if (snd_BUG_ON(!pool))
244 spin_lock_irqsave(&pool->lock, flags);
245 free_cell(pool, cell);
246 if (snd_seq_ev_is_variable(&cell->event)) {
247 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
248 struct snd_seq_event_cell *curp, *nextptr;
249 curp = cell->event.data.ext.ptr;
250 for (; curp; curp = nextptr) {
251 nextptr = curp->next;
252 curp->next = pool->free;
253 free_cell(pool, curp);
257 if (waitqueue_active(&pool->output_sleep)) {
258 /* has enough space now? */
259 if (snd_seq_output_ok(pool))
260 wake_up(&pool->output_sleep);
262 spin_unlock_irqrestore(&pool->lock, flags);
267 * allocate an event cell.
269 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
270 struct snd_seq_event_cell **cellp,
271 int nonblock, struct file *file,
272 struct mutex *mutexp)
274 struct snd_seq_event_cell *cell;
277 wait_queue_entry_t wait;
284 init_waitqueue_entry(&wait, current);
285 spin_lock_irqsave(&pool->lock, flags);
286 if (pool->ptr == NULL) { /* not initialized */
287 pr_debug("ALSA: seq: pool is not initialized\n");
291 while (pool->free == NULL && ! nonblock && ! pool->closing) {
293 set_current_state(TASK_INTERRUPTIBLE);
294 add_wait_queue(&pool->output_sleep, &wait);
295 spin_unlock_irqrestore(&pool->lock, flags);
297 mutex_unlock(mutexp);
301 spin_lock_irqsave(&pool->lock, flags);
302 remove_wait_queue(&pool->output_sleep, &wait);
304 if (signal_pending(current)) {
309 if (pool->closing) { /* closing.. */
317 pool->free = cell->next;
318 atomic_inc(&pool->counter);
319 used = atomic_read(&pool->counter);
320 if (pool->max_used < used)
321 pool->max_used = used;
322 pool->event_alloc_success++;
323 /* clear cell pointers */
327 pool->event_alloc_failures++;
331 spin_unlock_irqrestore(&pool->lock, flags);
337 * duplicate the event to a cell.
338 * if the event has external data, the data is decomposed to additional
341 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
342 struct snd_seq_event_cell **cellp, int nonblock,
343 struct file *file, struct mutex *mutexp)
347 struct snd_seq_event_cell *cell;
354 if (snd_seq_ev_is_variable(event)) {
355 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
356 ncells = DIV_ROUND_UP(extlen, sizeof(struct snd_seq_event));
358 if (ncells >= pool->total_elements)
361 err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
366 size = snd_seq_event_packet_size(event);
367 memcpy(&cell->ump, event, size);
368 #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
369 if (size < sizeof(cell->event))
370 cell->ump.raw.extra = 0;
374 if (snd_seq_ev_is_variable(event)) {
376 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
377 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
378 struct snd_seq_event_cell *src, *tmp, *tail;
381 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
382 cell->event.data.ext.ptr = NULL;
384 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
385 buf = (char *)event->data.ext.ptr;
388 while (ncells-- > 0) {
389 size = sizeof(struct snd_seq_event);
392 err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
396 if (cell->event.data.ext.ptr == NULL)
397 cell->event.data.ext.ptr = tmp;
402 if (is_chained && src) {
403 tmp->event = src->event;
405 } else if (is_usrptr) {
406 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
411 memcpy(&tmp->event, buf, size);
422 snd_seq_cell_free(cell);
428 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
431 poll_wait(file, &pool->output_sleep, wait);
432 return snd_seq_output_ok(pool);
436 /* allocate room specified number of events */
437 int snd_seq_pool_init(struct snd_seq_pool *pool)
440 struct snd_seq_event_cell *cellptr;
442 if (snd_BUG_ON(!pool))
445 cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
450 /* add new cells to the free cell list */
451 spin_lock_irq(&pool->lock);
453 spin_unlock_irq(&pool->lock);
461 for (cell = 0; cell < pool->size; cell++) {
462 cellptr = pool->ptr + cell;
463 cellptr->pool = pool;
464 cellptr->next = pool->free;
465 pool->free = cellptr;
467 pool->room = (pool->size + 1) / 2;
469 /* init statistics */
471 pool->total_elements = pool->size;
472 spin_unlock_irq(&pool->lock);
476 /* refuse the further insertion to the pool */
477 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
481 if (snd_BUG_ON(!pool))
483 spin_lock_irqsave(&pool->lock, flags);
485 spin_unlock_irqrestore(&pool->lock, flags);
489 int snd_seq_pool_done(struct snd_seq_pool *pool)
491 struct snd_seq_event_cell *ptr;
493 if (snd_BUG_ON(!pool))
496 /* wait for closing all threads */
497 if (waitqueue_active(&pool->output_sleep))
498 wake_up(&pool->output_sleep);
500 while (atomic_read(&pool->counter) > 0)
501 schedule_timeout_uninterruptible(1);
503 /* release all resources */
504 spin_lock_irq(&pool->lock);
508 pool->total_elements = 0;
509 spin_unlock_irq(&pool->lock);
513 spin_lock_irq(&pool->lock);
515 spin_unlock_irq(&pool->lock);
521 /* init new memory pool */
522 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
524 struct snd_seq_pool *pool;
526 /* create pool block */
527 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
530 spin_lock_init(&pool->lock);
533 pool->total_elements = 0;
534 atomic_set(&pool->counter, 0);
536 init_waitqueue_head(&pool->output_sleep);
538 pool->size = poolsize;
540 /* init statistics */
545 /* remove memory pool */
546 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
548 struct snd_seq_pool *pool = *ppool;
553 snd_seq_pool_mark_closing(pool);
554 snd_seq_pool_done(pool);
559 /* exported to seq_clientmgr.c */
560 void snd_seq_info_pool(struct snd_info_buffer *buffer,
561 struct snd_seq_pool *pool, char *space)
565 snd_iprintf(buffer, "%sPool size : %d\n", space, pool->total_elements);
566 snd_iprintf(buffer, "%sCells in use : %d\n", space, atomic_read(&pool->counter));
567 snd_iprintf(buffer, "%sPeak cells in use : %d\n", space, pool->max_used);
568 snd_iprintf(buffer, "%sAlloc success : %d\n", space, pool->event_alloc_success);
569 snd_iprintf(buffer, "%sAlloc failures : %d\n", space, pool->event_alloc_failures);