61 lines
1.3 KiB
C
61 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_TTY_BUFFER_H
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#define _LINUX_TTY_BUFFER_H
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#include <linux/atomic.h>
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#include <linux/llist.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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struct tty_buffer {
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union {
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struct tty_buffer *next;
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struct llist_node free;
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};
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int used;
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int size;
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int commit;
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int lookahead; /* Lazy update on recv, can become less than "read" */
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int read;
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int flags;
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/* Data points here */
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unsigned long data[];
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};
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/* Values for .flags field of tty_buffer */
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#define TTYB_NORMAL 1 /* buffer has no flags buffer */
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static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
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{
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return ((unsigned char *)b->data) + ofs;
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}
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static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
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{
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return (char *)char_buf_ptr(b, ofs) + b->size;
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}
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struct tty_bufhead {
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struct tty_buffer *head; /* Queue head */
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struct work_struct work;
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struct mutex lock;
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atomic_t priority;
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struct tty_buffer sentinel;
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struct llist_head free; /* Free queue head */
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atomic_t mem_used; /* In-use buffers excluding free list */
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int mem_limit;
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struct tty_buffer *tail; /* Active buffer */
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};
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/*
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* When a break, frame error, or parity error happens, these codes are
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* stuffed into the flags buffer.
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*/
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#define TTY_NORMAL 0
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#define TTY_BREAK 1
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#define TTY_FRAME 2
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#define TTY_PARITY 3
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#define TTY_OVERRUN 4
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#endif
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