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2e2b4b8961
The struct tty_buffer has flags which is only used for storing TTYB_NORMAL. There is also a few quite confusing operations for checking the presense of TTYB_NORMAL. Simplify things by converting flags to bool. Despite the name remaining the same, the meaning of "flags" is altered slightly by this change. Previously it referred to flags of the buffer (only TTYB_NORMAL being used as a flag). After this change, flags tell whether the buffer contains/should be allocated with flags array along with character data array. It is much more suitable name that TTYB_NORMAL was for this purpose, thus the name remains. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20221019105504.16800-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
57 lines
1.3 KiB
C
57 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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bool flags;
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/* Data points here */
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unsigned long data[];
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};
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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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