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1 /*
2 * QEMU Character device internals
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #ifndef CHARDEV_INTERNAL_H
26 #define CHARDEV_INTERNAL_H
27
28 #include "chardev/char.h"
29 #include "chardev/char-fe.h"
30 #include "qom/object.h"
31
32 #define MAX_HUB 4
33 #define MAX_MUX 4
34 #define MUX_BUFFER_SIZE 32 /* Must be a power of 2. */
35 #define MUX_BUFFER_MASK (MUX_BUFFER_SIZE - 1)
36
37 struct MuxChardev {
38 Chardev parent;
39 /* Linked frontends */
40 CharFrontend *frontends[MAX_MUX];
41 /* frontend of the underlying muxed chardev */
42 CharFrontend chr;
43 unsigned long mux_bitset;
44 int focus;
45 bool term_got_escape;
46 /* Intermediate input buffer catches escape sequences even if the
47 currently active device is not accepting any input - but only until it
48 is full as well. */
49 unsigned char buffer[MAX_MUX][MUX_BUFFER_SIZE];
50 unsigned int prod[MAX_MUX];
51 unsigned int cons[MAX_MUX];
52 int timestamps;
53
54 /* Protected by the Chardev chr_write_lock. */
55 bool linestart;
56 int64_t timestamps_start;
57 };
58 typedef struct MuxChardev MuxChardev;
59 typedef struct HubChardev HubChardev;
60 typedef struct HubCharBackend HubCharBackend;
61
62 /*
63 * Back-pointer on a hub, actual backend and its index in
64 * `hub->backends` array
65 */
66 struct HubCharBackend {
67 HubChardev *hub;
68 CharFrontend fe;
69 unsigned int be_ind;
70 };
71
72 struct HubChardev {
73 Chardev parent;
74 /* Linked backends */
75 HubCharBackend backends[MAX_HUB];
76 /*
77 * Number of backends attached to this hub. Once attached, a
78 * backend can't be detached, so the counter is only increasing.
79 * To safely remove a backend, hub has to be removed first.
80 */
81 unsigned int be_cnt;
82 /*
83 * Number of CHR_EVEN_OPENED events from all backends. Needed to
84 * send CHR_EVEN_CLOSED only when counter goes to zero.
85 */
86 unsigned int be_event_opened_cnt;
87 /*
88 * Counters of written bytes from a single frontend device
89 * to multiple backend devices.
90 */
91 unsigned int be_written[MAX_HUB];
92 unsigned int be_min_written;
93 /*
94 * Index of a backend device which got EAGAIN on last write,
95 * -1 is invalid index.
96 */
97 int be_eagain_ind;
98 };
99 typedef struct HubChardev HubChardev;
100
101 DECLARE_INSTANCE_CHECKER(MuxChardev, MUX_CHARDEV,
102 TYPE_CHARDEV_MUX)
103 DECLARE_INSTANCE_CHECKER(HubChardev, HUB_CHARDEV,
104 TYPE_CHARDEV_HUB)
105
106 #define CHARDEV_IS_MUX(chr) \
107 object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_MUX)
108 #define CHARDEV_IS_HUB(chr) \
109 object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_HUB)
110
111 bool mux_chr_attach_frontend(MuxChardev *d, CharFrontend *c,
112 unsigned int *tag, Error **errp);
113 bool mux_chr_detach_frontend(MuxChardev *d, unsigned int tag);
114 void mux_set_focus(Chardev *chr, unsigned int focus);
115 void mux_chr_send_all_event(Chardev *chr, QEMUChrEvent event);
116
117 Object *get_chardevs_root(void);
118
119 #endif /* CHARDEV_INTERNAL_H */