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8d29e002 JS |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_TTY_BUFFER_H | |
3 | #define _LINUX_TTY_BUFFER_H | |
4 | ||
5 | #include <linux/atomic.h> | |
6 | #include <linux/llist.h> | |
7 | #include <linux/mutex.h> | |
8 | #include <linux/workqueue.h> | |
9 | ||
10 | struct tty_buffer { | |
11 | union { | |
12 | struct tty_buffer *next; | |
13 | struct llist_node free; | |
14 | }; | |
b97552eb JSS |
15 | unsigned int used; |
16 | unsigned int size; | |
17 | unsigned int commit; | |
18 | unsigned int lookahead; /* Lazy update on recv, can become less than "read" */ | |
19 | unsigned int read; | |
2e2b4b89 | 20 | bool flags; |
8d29e002 | 21 | /* Data points here */ |
d4d13ff3 | 22 | u8 data[] __aligned(sizeof(unsigned long)); |
8d29e002 JS |
23 | }; |
24 | ||
5db35be9 | 25 | static inline u8 *char_buf_ptr(struct tty_buffer *b, unsigned int ofs) |
8d29e002 | 26 | { |
d4d13ff3 | 27 | return b->data + ofs; |
8d29e002 JS |
28 | } |
29 | ||
5db35be9 | 30 | static inline u8 *flag_buf_ptr(struct tty_buffer *b, unsigned int ofs) |
8d29e002 | 31 | { |
892bc209 | 32 | return char_buf_ptr(b, ofs) + b->size; |
8d29e002 JS |
33 | } |
34 | ||
35 | struct tty_bufhead { | |
36 | struct tty_buffer *head; /* Queue head */ | |
37 | struct work_struct work; | |
38 | struct mutex lock; | |
39 | atomic_t priority; | |
40 | struct tty_buffer sentinel; | |
41 | struct llist_head free; /* Free queue head */ | |
42 | atomic_t mem_used; /* In-use buffers excluding free list */ | |
43 | int mem_limit; | |
44 | struct tty_buffer *tail; /* Active buffer */ | |
45 | }; | |
46 | ||
47 | /* | |
48 | * When a break, frame error, or parity error happens, these codes are | |
49 | * stuffed into the flags buffer. | |
50 | */ | |
51 | #define TTY_NORMAL 0 | |
52 | #define TTY_BREAK 1 | |
53 | #define TTY_FRAME 2 | |
54 | #define TTY_PARITY 3 | |
55 | #define TTY_OVERRUN 4 | |
56 | ||
57 | #endif |