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(void *ptr, void *src, int size)
119 memcpy(*bufptr, src, size);
124 static int seq_copy_in_user(void *ptr, void *src, int size)
126 char __user **bufptr = ptr;
128 if (copy_to_user(*bufptr, src, size))
134 int snd_seq_expand_var_event(const struct snd_seq_event *event, int count, char *buf,
135 int in_kernel, int size_aligned)
140 if ((len = get_var_len(event)) < 0)
143 if (size_aligned > 0)
144 newlen = roundup(len, size_aligned);
148 if (event->data.ext.len & SNDRV_SEQ_EXT_USRPTR) {
151 if (copy_from_user(buf, (void __force __user *)event->data.ext.ptr, len))
155 err = snd_seq_dump_var_event(event,
156 in_kernel ? seq_copy_in_kernel : seq_copy_in_user,
158 return err < 0 ? err : newlen;
160 EXPORT_SYMBOL(snd_seq_expand_var_event);
163 * release this cell, free extended data if available
166 static inline void free_cell(struct snd_seq_pool *pool,
167 struct snd_seq_event_cell *cell)
169 cell->next = pool->free;
171 atomic_dec(&pool->counter);
174 void snd_seq_cell_free(struct snd_seq_event_cell * cell)
177 struct snd_seq_pool *pool;
179 if (snd_BUG_ON(!cell))
182 if (snd_BUG_ON(!pool))
185 spin_lock_irqsave(&pool->lock, flags);
186 free_cell(pool, cell);
187 if (snd_seq_ev_is_variable(&cell->event)) {
188 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
189 struct snd_seq_event_cell *curp, *nextptr;
190 curp = cell->event.data.ext.ptr;
191 for (; curp; curp = nextptr) {
192 nextptr = curp->next;
193 curp->next = pool->free;
194 free_cell(pool, curp);
198 if (waitqueue_active(&pool->output_sleep)) {
199 /* has enough space now? */
200 if (snd_seq_output_ok(pool))
201 wake_up(&pool->output_sleep);
203 spin_unlock_irqrestore(&pool->lock, flags);
208 * allocate an event cell.
210 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
211 struct snd_seq_event_cell **cellp,
212 int nonblock, struct file *file,
213 struct mutex *mutexp)
215 struct snd_seq_event_cell *cell;
218 wait_queue_entry_t wait;
225 init_waitqueue_entry(&wait, current);
226 spin_lock_irqsave(&pool->lock, flags);
227 if (pool->ptr == NULL) { /* not initialized */
228 pr_debug("ALSA: seq: pool is not initialized\n");
232 while (pool->free == NULL && ! nonblock && ! pool->closing) {
234 set_current_state(TASK_INTERRUPTIBLE);
235 add_wait_queue(&pool->output_sleep, &wait);
236 spin_unlock_irqrestore(&pool->lock, flags);
238 mutex_unlock(mutexp);
242 spin_lock_irqsave(&pool->lock, flags);
243 remove_wait_queue(&pool->output_sleep, &wait);
245 if (signal_pending(current)) {
250 if (pool->closing) { /* closing.. */
258 pool->free = cell->next;
259 atomic_inc(&pool->counter);
260 used = atomic_read(&pool->counter);
261 if (pool->max_used < used)
262 pool->max_used = used;
263 pool->event_alloc_success++;
264 /* clear cell pointers */
268 pool->event_alloc_failures++;
272 spin_unlock_irqrestore(&pool->lock, flags);
278 * duplicate the event to a cell.
279 * if the event has external data, the data is decomposed to additional
282 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
283 struct snd_seq_event_cell **cellp, int nonblock,
284 struct file *file, struct mutex *mutexp)
288 struct snd_seq_event_cell *cell;
294 if (snd_seq_ev_is_variable(event)) {
295 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
296 ncells = (extlen + sizeof(struct snd_seq_event) - 1) / sizeof(struct snd_seq_event);
298 if (ncells >= pool->total_elements)
301 err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
306 cell->event = *event;
309 if (snd_seq_ev_is_variable(event)) {
311 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
312 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
313 struct snd_seq_event_cell *src, *tmp, *tail;
316 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
317 cell->event.data.ext.ptr = NULL;
319 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
320 buf = (char *)event->data.ext.ptr;
323 while (ncells-- > 0) {
324 int size = sizeof(struct snd_seq_event);
327 err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
331 if (cell->event.data.ext.ptr == NULL)
332 cell->event.data.ext.ptr = tmp;
337 if (is_chained && src) {
338 tmp->event = src->event;
340 } else if (is_usrptr) {
341 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
346 memcpy(&tmp->event, buf, size);
357 snd_seq_cell_free(cell);
363 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
366 poll_wait(file, &pool->output_sleep, wait);
367 return snd_seq_output_ok(pool);
371 /* allocate room specified number of events */
372 int snd_seq_pool_init(struct snd_seq_pool *pool)
375 struct snd_seq_event_cell *cellptr;
377 if (snd_BUG_ON(!pool))
380 cellptr = kvmalloc_array(sizeof(struct snd_seq_event_cell), pool->size,
385 /* add new cells to the free cell list */
386 spin_lock_irq(&pool->lock);
388 spin_unlock_irq(&pool->lock);
396 for (cell = 0; cell < pool->size; cell++) {
397 cellptr = pool->ptr + cell;
398 cellptr->pool = pool;
399 cellptr->next = pool->free;
400 pool->free = cellptr;
402 pool->room = (pool->size + 1) / 2;
404 /* init statistics */
406 pool->total_elements = pool->size;
407 spin_unlock_irq(&pool->lock);
411 /* refuse the further insertion to the pool */
412 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
416 if (snd_BUG_ON(!pool))
418 spin_lock_irqsave(&pool->lock, flags);
420 spin_unlock_irqrestore(&pool->lock, flags);
424 int snd_seq_pool_done(struct snd_seq_pool *pool)
426 struct snd_seq_event_cell *ptr;
428 if (snd_BUG_ON(!pool))
431 /* wait for closing all threads */
432 if (waitqueue_active(&pool->output_sleep))
433 wake_up(&pool->output_sleep);
435 while (atomic_read(&pool->counter) > 0)
436 schedule_timeout_uninterruptible(1);
438 /* release all resources */
439 spin_lock_irq(&pool->lock);
443 pool->total_elements = 0;
444 spin_unlock_irq(&pool->lock);
448 spin_lock_irq(&pool->lock);
450 spin_unlock_irq(&pool->lock);
456 /* init new memory pool */
457 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
459 struct snd_seq_pool *pool;
461 /* create pool block */
462 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
465 spin_lock_init(&pool->lock);
468 pool->total_elements = 0;
469 atomic_set(&pool->counter, 0);
471 init_waitqueue_head(&pool->output_sleep);
473 pool->size = poolsize;
475 /* init statistics */
480 /* remove memory pool */
481 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
483 struct snd_seq_pool *pool = *ppool;
488 snd_seq_pool_mark_closing(pool);
489 snd_seq_pool_done(pool);
494 /* exported to seq_clientmgr.c */
495 void snd_seq_info_pool(struct snd_info_buffer *buffer,
496 struct snd_seq_pool *pool, char *space)
500 snd_iprintf(buffer, "%sPool size : %d\n", space, pool->total_elements);
501 snd_iprintf(buffer, "%sCells in use : %d\n", space, atomic_read(&pool->counter));
502 snd_iprintf(buffer, "%sPeak cells in use : %d\n", space, pool->max_used);
503 snd_iprintf(buffer, "%sAlloc success : %d\n", space, pool->event_alloc_success);
504 snd_iprintf(buffer, "%sAlloc failures : %d\n", space, pool->event_alloc_failures);