18d29e002SJiri Slaby /* SPDX-License-Identifier: GPL-2.0 */ 28d29e002SJiri Slaby #ifndef _LINUX_TTY_BUFFER_H 38d29e002SJiri Slaby #define _LINUX_TTY_BUFFER_H 48d29e002SJiri Slaby 58d29e002SJiri Slaby #include <linux/atomic.h> 68d29e002SJiri Slaby #include <linux/llist.h> 78d29e002SJiri Slaby #include <linux/mutex.h> 88d29e002SJiri Slaby #include <linux/workqueue.h> 98d29e002SJiri Slaby 108d29e002SJiri Slaby struct tty_buffer { 118d29e002SJiri Slaby union { 128d29e002SJiri Slaby struct tty_buffer *next; 138d29e002SJiri Slaby struct llist_node free; 148d29e002SJiri Slaby }; 158d29e002SJiri Slaby int used; 168d29e002SJiri Slaby int size; 178d29e002SJiri Slaby int commit; 186bb6fa69SIlpo Järvinen int lookahead; /* Lazy update on recv, can become less than "read" */ 198d29e002SJiri Slaby int read; 20*2e2b4b89SIlpo Järvinen bool flags; 218d29e002SJiri Slaby /* Data points here */ 228d29e002SJiri Slaby unsigned long data[]; 238d29e002SJiri Slaby }; 248d29e002SJiri Slaby 258d29e002SJiri Slaby static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs) 268d29e002SJiri Slaby { 278d29e002SJiri Slaby return ((unsigned char *)b->data) + ofs; 288d29e002SJiri Slaby } 298d29e002SJiri Slaby 308d29e002SJiri Slaby static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs) 318d29e002SJiri Slaby { 328d29e002SJiri Slaby return (char *)char_buf_ptr(b, ofs) + b->size; 338d29e002SJiri Slaby } 348d29e002SJiri Slaby 358d29e002SJiri Slaby struct tty_bufhead { 368d29e002SJiri Slaby struct tty_buffer *head; /* Queue head */ 378d29e002SJiri Slaby struct work_struct work; 388d29e002SJiri Slaby struct mutex lock; 398d29e002SJiri Slaby atomic_t priority; 408d29e002SJiri Slaby struct tty_buffer sentinel; 418d29e002SJiri Slaby struct llist_head free; /* Free queue head */ 428d29e002SJiri Slaby atomic_t mem_used; /* In-use buffers excluding free list */ 438d29e002SJiri Slaby int mem_limit; 448d29e002SJiri Slaby struct tty_buffer *tail; /* Active buffer */ 458d29e002SJiri Slaby }; 468d29e002SJiri Slaby 478d29e002SJiri Slaby /* 488d29e002SJiri Slaby * When a break, frame error, or parity error happens, these codes are 498d29e002SJiri Slaby * stuffed into the flags buffer. 508d29e002SJiri Slaby */ 518d29e002SJiri Slaby #define TTY_NORMAL 0 528d29e002SJiri Slaby #define TTY_BREAK 1 538d29e002SJiri Slaby #define TTY_FRAME 2 548d29e002SJiri Slaby #define TTY_PARITY 3 558d29e002SJiri Slaby #define TTY_OVERRUN 4 568d29e002SJiri Slaby 578d29e002SJiri Slaby #endif 58