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 | */ |
6 | #ifndef __SND_SEQ_MEMORYMGR_H |
7 | #define __SND_SEQ_MEMORYMGR_H |
8 | |
9 | #include <sound/seq_kernel.h> |
10 | #include <linux/poll.h> |
11 | |
12 | struct snd_info_buffer; |
13 | |
14 | /* aliasing for legacy and UMP event packet handling */ |
15 | union __snd_seq_event { |
16 | struct snd_seq_event legacy; |
17 | #if IS_ENABLED(CONFIG_SND_SEQ_UMP) |
18 | struct snd_seq_ump_event ump; |
19 | #endif |
20 | struct { |
21 | struct snd_seq_event event; |
22 | #if IS_ENABLED(CONFIG_SND_SEQ_UMP) |
23 | u32 ; |
24 | #endif |
25 | } __packed raw; |
26 | }; |
27 | |
28 | /* container for sequencer event (internal use) */ |
29 | struct snd_seq_event_cell { |
30 | union { |
31 | struct snd_seq_event event; |
32 | union __snd_seq_event ump; |
33 | }; |
34 | struct snd_seq_pool *pool; /* used pool */ |
35 | struct snd_seq_event_cell *next; /* next cell */ |
36 | }; |
37 | |
38 | /* design note: the pool is a contiguous block of memory, if we dynamicly |
39 | want to add additional cells to the pool be better store this in another |
40 | pool as we need to know the base address of the pool when releasing |
41 | memory. */ |
42 | |
43 | struct snd_seq_pool { |
44 | struct snd_seq_event_cell *ptr; /* pointer to first event chunk */ |
45 | struct snd_seq_event_cell *free; /* pointer to the head of the free list */ |
46 | |
47 | int total_elements; /* pool size actually allocated */ |
48 | atomic_t counter; /* cells free */ |
49 | |
50 | int size; /* pool size to be allocated */ |
51 | int room; /* watermark for sleep/wakeup */ |
52 | |
53 | int closing; |
54 | |
55 | /* statistics */ |
56 | int max_used; |
57 | int event_alloc_nopool; |
58 | int event_alloc_failures; |
59 | int event_alloc_success; |
60 | |
61 | /* Write locking */ |
62 | wait_queue_head_t output_sleep; |
63 | |
64 | /* Pool lock */ |
65 | spinlock_t lock; |
66 | }; |
67 | |
68 | void snd_seq_cell_free(struct snd_seq_event_cell *cell); |
69 | |
70 | int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event, |
71 | struct snd_seq_event_cell **cellp, int nonblock, |
72 | struct file *file, struct mutex *mutexp); |
73 | |
74 | /* return number of unused (free) cells */ |
75 | static inline int snd_seq_unused_cells(struct snd_seq_pool *pool) |
76 | { |
77 | return pool ? pool->total_elements - atomic_read(v: &pool->counter) : 0; |
78 | } |
79 | |
80 | /* return total number of allocated cells */ |
81 | static inline int snd_seq_total_cells(struct snd_seq_pool *pool) |
82 | { |
83 | return pool ? pool->total_elements : 0; |
84 | } |
85 | |
86 | /* init pool - allocate events */ |
87 | int snd_seq_pool_init(struct snd_seq_pool *pool); |
88 | |
89 | /* done pool - free events */ |
90 | void snd_seq_pool_mark_closing(struct snd_seq_pool *pool); |
91 | int snd_seq_pool_done(struct snd_seq_pool *pool); |
92 | |
93 | /* create pool */ |
94 | struct snd_seq_pool *snd_seq_pool_new(int poolsize); |
95 | |
96 | /* remove pool */ |
97 | int snd_seq_pool_delete(struct snd_seq_pool **pool); |
98 | |
99 | /* polling */ |
100 | int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file, poll_table *wait); |
101 | |
102 | void snd_seq_info_pool(struct snd_info_buffer *buffer, |
103 | struct snd_seq_pool *pool, char *space); |
104 | |
105 | #endif |
106 | |