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)
235 struct snd_seq_pool *pool;
237 if (snd_BUG_ON(!cell))
240 if (snd_BUG_ON(!pool))
243 guard(spinlock_irqsave)(&pool->lock);
244 free_cell(pool, cell);
245 if (snd_seq_ev_is_variable(&cell->event)) {
246 if (cell->event.data.ext.len & SNDRV_SEQ_EXT_CHAINED) {
247 struct snd_seq_event_cell *curp, *nextptr;
248 curp = cell->event.data.ext.ptr;
249 for (; curp; curp = nextptr) {
250 nextptr = curp->next;
251 curp->next = pool->free;
252 free_cell(pool, curp);
256 if (waitqueue_active(&pool->output_sleep)) {
257 /* has enough space now? */
258 if (snd_seq_output_ok(pool))
259 wake_up(&pool->output_sleep);
265 * allocate an event cell.
267 static int snd_seq_cell_alloc(struct snd_seq_pool *pool,
268 struct snd_seq_event_cell **cellp,
269 int nonblock, struct file *file,
270 struct mutex *mutexp)
272 struct snd_seq_event_cell *cell;
275 wait_queue_entry_t wait;
282 init_waitqueue_entry(&wait, current);
283 spin_lock_irqsave(&pool->lock, flags);
284 if (pool->ptr == NULL) { /* not initialized */
285 pr_debug("ALSA: seq: pool is not initialized\n");
289 while (pool->free == NULL && ! nonblock && ! pool->closing) {
291 set_current_state(TASK_INTERRUPTIBLE);
292 add_wait_queue(&pool->output_sleep, &wait);
293 spin_unlock_irqrestore(&pool->lock, flags);
295 mutex_unlock(mutexp);
299 spin_lock_irqsave(&pool->lock, flags);
300 remove_wait_queue(&pool->output_sleep, &wait);
302 if (signal_pending(current)) {
307 if (pool->closing) { /* closing.. */
315 pool->free = cell->next;
316 atomic_inc(&pool->counter);
317 used = atomic_read(&pool->counter);
318 if (pool->max_used < used)
319 pool->max_used = used;
320 pool->event_alloc_success++;
321 /* clear cell pointers */
325 pool->event_alloc_failures++;
329 spin_unlock_irqrestore(&pool->lock, flags);
335 * duplicate the event to a cell.
336 * if the event has external data, the data is decomposed to additional
339 int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
340 struct snd_seq_event_cell **cellp, int nonblock,
341 struct file *file, struct mutex *mutexp)
345 struct snd_seq_event_cell *cell;
352 if (snd_seq_ev_is_variable(event)) {
353 extlen = event->data.ext.len & ~SNDRV_SEQ_EXT_MASK;
354 ncells = DIV_ROUND_UP(extlen, sizeof(struct snd_seq_event));
356 if (ncells >= pool->total_elements)
359 err = snd_seq_cell_alloc(pool, &cell, nonblock, file, mutexp);
364 size = snd_seq_event_packet_size(event);
365 memcpy(&cell->ump, event, size);
366 #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
367 if (size < sizeof(cell->event))
368 cell->ump.raw.extra = 0;
372 if (snd_seq_ev_is_variable(event)) {
374 int is_chained = event->data.ext.len & SNDRV_SEQ_EXT_CHAINED;
375 int is_usrptr = event->data.ext.len & SNDRV_SEQ_EXT_USRPTR;
376 struct snd_seq_event_cell *src, *tmp, *tail;
379 cell->event.data.ext.len = extlen | SNDRV_SEQ_EXT_CHAINED;
380 cell->event.data.ext.ptr = NULL;
382 src = (struct snd_seq_event_cell *)event->data.ext.ptr;
383 buf = (char *)event->data.ext.ptr;
386 while (ncells-- > 0) {
387 size = sizeof(struct snd_seq_event);
390 err = snd_seq_cell_alloc(pool, &tmp, nonblock, file,
394 if (cell->event.data.ext.ptr == NULL)
395 cell->event.data.ext.ptr = tmp;
400 if (is_chained && src) {
401 tmp->event = src->event;
403 } else if (is_usrptr) {
404 if (copy_from_user(&tmp->event, (char __force __user *)buf, size)) {
409 memcpy(&tmp->event, buf, size);
420 snd_seq_cell_free(cell);
426 int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file,
429 poll_wait(file, &pool->output_sleep, wait);
430 return snd_seq_output_ok(pool);
434 /* allocate room specified number of events */
435 int snd_seq_pool_init(struct snd_seq_pool *pool)
438 struct snd_seq_event_cell *cellptr;
440 if (snd_BUG_ON(!pool))
443 cellptr = kvmalloc_array(pool->size,
444 sizeof(struct snd_seq_event_cell),
449 /* add new cells to the free cell list */
450 guard(spinlock_irq)(&pool->lock);
459 for (cell = 0; cell < pool->size; cell++) {
460 cellptr = pool->ptr + cell;
461 cellptr->pool = pool;
462 cellptr->next = pool->free;
463 pool->free = cellptr;
465 pool->room = (pool->size + 1) / 2;
467 /* init statistics */
469 pool->total_elements = pool->size;
473 /* refuse the further insertion to the pool */
474 void snd_seq_pool_mark_closing(struct snd_seq_pool *pool)
476 if (snd_BUG_ON(!pool))
478 guard(spinlock_irqsave)(&pool->lock);
483 int snd_seq_pool_done(struct snd_seq_pool *pool)
485 struct snd_seq_event_cell *ptr;
487 if (snd_BUG_ON(!pool))
490 /* wait for closing all threads */
491 if (waitqueue_active(&pool->output_sleep))
492 wake_up(&pool->output_sleep);
494 while (atomic_read(&pool->counter) > 0)
495 schedule_timeout_uninterruptible(1);
497 /* release all resources */
498 scoped_guard(spinlock_irq, &pool->lock) {
502 pool->total_elements = 0;
507 guard(spinlock_irq)(&pool->lock);
514 /* init new memory pool */
515 struct snd_seq_pool *snd_seq_pool_new(int poolsize)
517 struct snd_seq_pool *pool;
519 /* create pool block */
520 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
523 spin_lock_init(&pool->lock);
526 pool->total_elements = 0;
527 atomic_set(&pool->counter, 0);
529 init_waitqueue_head(&pool->output_sleep);
531 pool->size = poolsize;
533 /* init statistics */
538 /* remove memory pool */
539 int snd_seq_pool_delete(struct snd_seq_pool **ppool)
541 struct snd_seq_pool *pool = *ppool;
546 snd_seq_pool_mark_closing(pool);
547 snd_seq_pool_done(pool);
552 /* exported to seq_clientmgr.c */
553 void snd_seq_info_pool(struct snd_info_buffer *buffer,
554 struct snd_seq_pool *pool, char *space)
558 snd_iprintf(buffer, "%sPool size : %d\n", space, pool->total_elements);
559 snd_iprintf(buffer, "%sCells in use : %d\n", space, atomic_read(&pool->counter));
560 snd_iprintf(buffer, "%sPeak cells in use : %d\n", space, pool->max_used);
561 snd_iprintf(buffer, "%sAlloc success : %d\n", space, pool->event_alloc_success);
562 snd_iprintf(buffer, "%sAlloc failures : %d\n", space, pool->event_alloc_failures);