Commit | Line | Data |
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9e48565d AC |
1 | /* |
2 | * Tty port functions | |
3 | */ | |
4 | ||
5 | #include <linux/types.h> | |
6 | #include <linux/errno.h> | |
7 | #include <linux/tty.h> | |
8 | #include <linux/tty_driver.h> | |
9 | #include <linux/tty_flip.h> | |
10 | #include <linux/timer.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/wait.h> | |
16 | #include <linux/bitops.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
19 | ||
20 | void tty_port_init(struct tty_port *port) | |
21 | { | |
22 | memset(port, 0, sizeof(*port)); | |
23 | init_waitqueue_head(&port->open_wait); | |
24 | init_waitqueue_head(&port->close_wait); | |
25 | mutex_init(&port->mutex); | |
4a90f09b | 26 | spin_lock_init(&port->lock); |
9e48565d AC |
27 | port->close_delay = (50 * HZ) / 100; |
28 | port->closing_wait = (3000 * HZ) / 100; | |
29 | } | |
30 | EXPORT_SYMBOL(tty_port_init); | |
31 | ||
32 | int tty_port_alloc_xmit_buf(struct tty_port *port) | |
33 | { | |
34 | /* We may sleep in get_zeroed_page() */ | |
35 | mutex_lock(&port->mutex); | |
36 | if (port->xmit_buf == NULL) | |
37 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
38 | mutex_unlock(&port->mutex); | |
39 | if (port->xmit_buf == NULL) | |
40 | return -ENOMEM; | |
41 | return 0; | |
42 | } | |
43 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
44 | ||
45 | void tty_port_free_xmit_buf(struct tty_port *port) | |
46 | { | |
47 | mutex_lock(&port->mutex); | |
48 | if (port->xmit_buf != NULL) { | |
49 | free_page((unsigned long)port->xmit_buf); | |
50 | port->xmit_buf = NULL; | |
51 | } | |
52 | mutex_unlock(&port->mutex); | |
53 | } | |
54 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
55 | ||
56 | ||
4a90f09b AC |
57 | /** |
58 | * tty_port_tty_get - get a tty reference | |
59 | * @port: tty port | |
60 | * | |
61 | * Return a refcount protected tty instance or NULL if the port is not | |
62 | * associated with a tty (eg due to close or hangup) | |
63 | */ | |
64 | ||
65 | struct tty_struct *tty_port_tty_get(struct tty_port *port) | |
66 | { | |
67 | unsigned long flags; | |
68 | struct tty_struct *tty; | |
69 | ||
70 | spin_lock_irqsave(&port->lock, flags); | |
71 | tty = tty_kref_get(port->tty); | |
72 | spin_unlock_irqrestore(&port->lock, flags); | |
73 | return tty; | |
74 | } | |
75 | EXPORT_SYMBOL(tty_port_tty_get); | |
76 | ||
77 | /** | |
78 | * tty_port_tty_set - set the tty of a port | |
79 | * @port: tty port | |
80 | * @tty: the tty | |
81 | * | |
82 | * Associate the port and tty pair. Manages any internal refcounts. | |
83 | * Pass NULL to deassociate a port | |
84 | */ | |
85 | ||
86 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) | |
87 | { | |
88 | unsigned long flags; | |
89 | ||
90 | spin_lock_irqsave(&port->lock, flags); | |
91 | if (port->tty) | |
92 | tty_kref_put(port->tty); | |
93 | port->tty = tty; | |
94 | spin_unlock_irqrestore(&port->lock, flags); | |
95 | } | |
96 | EXPORT_SYMBOL(tty_port_tty_set); |