stdio_console.c (4842B)
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com) 4 */ 5 6#include <linux/posix_types.h> 7#include <linux/tty.h> 8#include <linux/tty_flip.h> 9#include <linux/types.h> 10#include <linux/major.h> 11#include <linux/kdev_t.h> 12#include <linux/console.h> 13#include <linux/string.h> 14#include <linux/sched.h> 15#include <linux/list.h> 16#include <linux/init.h> 17#include <linux/interrupt.h> 18#include <linux/slab.h> 19#include <linux/hardirq.h> 20#include <asm/current.h> 21#include <asm/irq.h> 22#include "stdio_console.h" 23#include "chan.h" 24#include <irq_user.h> 25#include "mconsole_kern.h" 26#include <init.h> 27 28#define MAX_TTYS (16) 29 30static void stdio_announce(char *dev_name, int dev) 31{ 32 printk(KERN_INFO "Virtual console %d assigned device '%s'\n", dev, 33 dev_name); 34} 35 36/* Almost const, except that xterm_title may be changed in an initcall */ 37static struct chan_opts opts = { 38 .announce = stdio_announce, 39 .xterm_title = "Virtual Console #%d", 40 .raw = 1, 41}; 42 43static int con_config(char *str, char **error_out); 44static int con_get_config(char *dev, char *str, int size, char **error_out); 45static int con_remove(int n, char **con_remove); 46 47 48/* Const, except for .mc.list */ 49static struct line_driver driver = { 50 .name = "UML console", 51 .device_name = "tty", 52 .major = TTY_MAJOR, 53 .minor_start = 0, 54 .type = TTY_DRIVER_TYPE_CONSOLE, 55 .subtype = SYSTEM_TYPE_CONSOLE, 56 .read_irq_name = "console", 57 .write_irq_name = "console-write", 58 .mc = { 59 .list = LIST_HEAD_INIT(driver.mc.list), 60 .name = "con", 61 .config = con_config, 62 .get_config = con_get_config, 63 .id = line_id, 64 .remove = con_remove, 65 }, 66}; 67 68/* The array is initialized by line_init, at initcall time. The 69 * elements are locked individually as needed. 70 */ 71static char *vt_conf[MAX_TTYS]; 72static char *def_conf; 73static struct line vts[MAX_TTYS]; 74 75static int con_config(char *str, char **error_out) 76{ 77 return line_config(vts, ARRAY_SIZE(vts), str, &opts, error_out); 78} 79 80static int con_get_config(char *dev, char *str, int size, char **error_out) 81{ 82 return line_get_config(dev, vts, ARRAY_SIZE(vts), str, size, error_out); 83} 84 85static int con_remove(int n, char **error_out) 86{ 87 return line_remove(vts, ARRAY_SIZE(vts), n, error_out); 88} 89 90/* Set in an initcall, checked in an exitcall */ 91static int con_init_done = 0; 92 93static int con_install(struct tty_driver *driver, struct tty_struct *tty) 94{ 95 return line_install(driver, tty, &vts[tty->index]); 96} 97 98static const struct tty_operations console_ops = { 99 .open = line_open, 100 .install = con_install, 101 .close = line_close, 102 .write = line_write, 103 .write_room = line_write_room, 104 .chars_in_buffer = line_chars_in_buffer, 105 .flush_buffer = line_flush_buffer, 106 .flush_chars = line_flush_chars, 107 .throttle = line_throttle, 108 .unthrottle = line_unthrottle, 109 .hangup = line_hangup, 110}; 111 112static void uml_console_write(struct console *console, const char *string, 113 unsigned len) 114{ 115 struct line *line = &vts[console->index]; 116 unsigned long flags; 117 118 spin_lock_irqsave(&line->lock, flags); 119 console_write_chan(line->chan_out, string, len); 120 spin_unlock_irqrestore(&line->lock, flags); 121} 122 123static struct tty_driver *uml_console_device(struct console *c, int *index) 124{ 125 *index = c->index; 126 return driver.driver; 127} 128 129static int uml_console_setup(struct console *co, char *options) 130{ 131 struct line *line = &vts[co->index]; 132 133 return console_open_chan(line, co); 134} 135 136/* No locking for register_console call - relies on single-threaded initcalls */ 137static struct console stdiocons = { 138 .name = "tty", 139 .write = uml_console_write, 140 .device = uml_console_device, 141 .setup = uml_console_setup, 142 .flags = CON_PRINTBUFFER|CON_ANYTIME, 143 .index = -1, 144}; 145 146static int stdio_init(void) 147{ 148 char *new_title; 149 int err; 150 int i; 151 152 err = register_lines(&driver, &console_ops, vts, 153 ARRAY_SIZE(vts)); 154 if (err) 155 return err; 156 157 printk(KERN_INFO "Initialized stdio console driver\n"); 158 159 new_title = add_xterm_umid(opts.xterm_title); 160 if(new_title != NULL) 161 opts.xterm_title = new_title; 162 163 for (i = 0; i < MAX_TTYS; i++) { 164 char *error; 165 char *s = vt_conf[i]; 166 if (!s) 167 s = def_conf; 168 if (!s) 169 s = i ? CONFIG_CON_CHAN : CONFIG_CON_ZERO_CHAN; 170 if (setup_one_line(vts, i, s, &opts, &error)) 171 printk(KERN_ERR "setup_one_line failed for " 172 "device %d : %s\n", i, error); 173 } 174 175 con_init_done = 1; 176 register_console(&stdiocons); 177 return 0; 178} 179late_initcall(stdio_init); 180 181static void console_exit(void) 182{ 183 if (!con_init_done) 184 return; 185 close_lines(vts, ARRAY_SIZE(vts)); 186} 187__uml_exitcall(console_exit); 188 189static int console_chan_setup(char *str) 190{ 191 if (!strncmp(str, "sole=", 5)) /* console= option specifies tty */ 192 return 0; 193 194 line_setup(vt_conf, MAX_TTYS, &def_conf, str, "console"); 195 return 1; 196} 197__setup("con", console_chan_setup); 198__channel_help(console_chan_setup, "con");