64 lines
1.2 KiB
C
64 lines
1.2 KiB
C
/*
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* linux/kernel/chr_drv/pty.c
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*
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* (C) 1991 Linus Torvalds
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*/
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/*
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* pty.c
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*
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* This module implements the pty functions
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* void mpty_write(struct tty_struct * queue);
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* void spty_write(struct tty_struct * queue);
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*/
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#include <linux/tty.h>
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#include <linux/sched.h>
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#include <asm/system.h>
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#include <asm/io.h>
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static inline void pty_copy(struct tty_struct * from, struct tty_struct * to)
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{
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char c;
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while (!from->stopped && !EMPTY(from->write_q)) {
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if (FULL(to->read_q)) {
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if (FULL(to->secondary))
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break;
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copy_to_cooked(to);
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continue;
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}
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GETCH(from->write_q,c);
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PUTCH(c,to->read_q);
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if (current->signal & ~current->blocked)
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break;
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}
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copy_to_cooked(to);
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wake_up(&from->write_q->proc_list);
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}
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/*
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* This routine gets called when tty_write has put something into
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* the write_queue. It copies the input to the output-queue of it's
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* slave.
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*/
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void mpty_write(struct tty_struct * tty)
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{
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int nr = tty - tty_table;
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if ((nr >> 6) != 2)
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printk("bad mpty\n\r");
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else
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pty_copy(tty,tty+64);
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}
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void spty_write(struct tty_struct * tty)
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{
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int nr = tty - tty_table;
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if ((nr >> 6) != 3)
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printk("bad spty\n\r");
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else
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pty_copy(tty,tty-64);
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}
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