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 CharBackend *backends[MAX_MUX]; 41 /* Linked backend */ 42 CharBackend 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 CharBackend be; 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, CharBackend *b, 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 */ 120