linux/arch/um/drivers/ssl.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* 
   3 * Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
   4 */
   5
   6#include <linux/fs.h>
   7#include <linux/tty.h>
   8#include <linux/tty_driver.h>
   9#include <linux/major.h>
  10#include <linux/mm.h>
  11#include <linux/init.h>
  12#include <linux/console.h>
  13#include <asm/termbits.h>
  14#include <asm/irq.h>
  15#include "chan.h"
  16#include <init.h>
  17#include <irq_user.h>
  18#include "mconsole_kern.h"
  19
  20static const int ssl_version = 1;
  21
  22#define NR_PORTS 64
  23
  24static void ssl_announce(char *dev_name, int dev)
  25{
  26        printk(KERN_INFO "Serial line %d assigned device '%s'\n", dev,
  27               dev_name);
  28}
  29
  30/* Almost const, except that xterm_title may be changed in an initcall */
  31static struct chan_opts opts = {
  32        .announce       = ssl_announce,
  33        .xterm_title    = "Serial Line #%d",
  34        .raw            = 1,
  35};
  36
  37static int ssl_config(char *str, char **error_out);
  38static int ssl_get_config(char *dev, char *str, int size, char **error_out);
  39static int ssl_remove(int n, char **error_out);
  40
  41
  42/* Const, except for .mc.list */
  43static struct line_driver driver = {
  44        .name                   = "UML serial line",
  45        .device_name            = "ttyS",
  46        .major                  = TTY_MAJOR,
  47        .minor_start            = 64,
  48        .type                   = TTY_DRIVER_TYPE_SERIAL,
  49        .subtype                = 0,
  50        .read_irq               = SSL_IRQ,
  51        .read_irq_name          = "ssl",
  52        .write_irq              = SSL_WRITE_IRQ,
  53        .write_irq_name         = "ssl-write",
  54        .mc  = {
  55                .list           = LIST_HEAD_INIT(driver.mc.list),
  56                .name           = "ssl",
  57                .config         = ssl_config,
  58                .get_config     = ssl_get_config,
  59                .id             = line_id,
  60                .remove         = ssl_remove,
  61        },
  62};
  63
  64/* The array is initialized by line_init, at initcall time.  The
  65 * elements are locked individually as needed.
  66 */
  67static char *conf[NR_PORTS];
  68static char *def_conf = CONFIG_SSL_CHAN;
  69static struct line serial_lines[NR_PORTS];
  70
  71static int ssl_config(char *str, char **error_out)
  72{
  73        return line_config(serial_lines, ARRAY_SIZE(serial_lines), str, &opts,
  74                           error_out);
  75}
  76
  77static int ssl_get_config(char *dev, char *str, int size, char **error_out)
  78{
  79        return line_get_config(dev, serial_lines, ARRAY_SIZE(serial_lines), str,
  80                               size, error_out);
  81}
  82
  83static int ssl_remove(int n, char **error_out)
  84{
  85        return line_remove(serial_lines, ARRAY_SIZE(serial_lines), n,
  86                           error_out);
  87}
  88
  89static int ssl_install(struct tty_driver *driver, struct tty_struct *tty)
  90{
  91        return line_install(driver, tty, &serial_lines[tty->index]);
  92}
  93
  94static const struct tty_operations ssl_ops = {
  95        .open                   = line_open,
  96        .close                  = line_close,
  97        .write                  = line_write,
  98        .write_room             = line_write_room,
  99        .chars_in_buffer        = line_chars_in_buffer,
 100        .flush_buffer           = line_flush_buffer,
 101        .flush_chars            = line_flush_chars,
 102        .throttle               = line_throttle,
 103        .unthrottle             = line_unthrottle,
 104        .install                = ssl_install,
 105        .hangup                 = line_hangup,
 106};
 107
 108/* Changed by ssl_init and referenced by ssl_exit, which are both serialized
 109 * by being an initcall and exitcall, respectively.
 110 */
 111static int ssl_init_done = 0;
 112
 113static void ssl_console_write(struct console *c, const char *string,
 114                              unsigned len)
 115{
 116        struct line *line = &serial_lines[c->index];
 117        unsigned long flags;
 118
 119        spin_lock_irqsave(&line->lock, flags);
 120        console_write_chan(line->chan_out, string, len);
 121        spin_unlock_irqrestore(&line->lock, flags);
 122}
 123
 124static struct tty_driver *ssl_console_device(struct console *c, int *index)
 125{
 126        *index = c->index;
 127        return driver.driver;
 128}
 129
 130static int ssl_console_setup(struct console *co, char *options)
 131{
 132        struct line *line = &serial_lines[co->index];
 133
 134        return console_open_chan(line, co);
 135}
 136
 137/* No locking for register_console call - relies on single-threaded initcalls */
 138static struct console ssl_cons = {
 139        .name           = "ttyS",
 140        .write          = ssl_console_write,
 141        .device         = ssl_console_device,
 142        .setup          = ssl_console_setup,
 143        .flags          = CON_PRINTBUFFER|CON_ANYTIME,
 144        .index          = -1,
 145};
 146
 147static int ssl_init(void)
 148{
 149        char *new_title;
 150        int err;
 151        int i;
 152
 153        printk(KERN_INFO "Initializing software serial port version %d\n",
 154               ssl_version);
 155
 156        err = register_lines(&driver, &ssl_ops, serial_lines,
 157                                    ARRAY_SIZE(serial_lines));
 158        if (err)
 159                return err;
 160
 161        new_title = add_xterm_umid(opts.xterm_title);
 162        if (new_title != NULL)
 163                opts.xterm_title = new_title;
 164
 165        for (i = 0; i < NR_PORTS; i++) {
 166                char *error;
 167                char *s = conf[i];
 168                if (!s)
 169                        s = def_conf;
 170                if (setup_one_line(serial_lines, i, s, &opts, &error))
 171                        printk(KERN_ERR "setup_one_line failed for "
 172                               "device %d : %s\n", i, error);
 173        }
 174
 175        ssl_init_done = 1;
 176        register_console(&ssl_cons);
 177        return 0;
 178}
 179late_initcall(ssl_init);
 180
 181static void ssl_exit(void)
 182{
 183        if (!ssl_init_done)
 184                return;
 185        close_lines(serial_lines, ARRAY_SIZE(serial_lines));
 186}
 187__uml_exitcall(ssl_exit);
 188
 189static int ssl_chan_setup(char *str)
 190{
 191        line_setup(conf, NR_PORTS, &def_conf, str, "serial line");
 192        return 1;
 193}
 194
 195__setup("ssl", ssl_chan_setup);
 196__channel_help(ssl_chan_setup, "ssl");
 197
 198static int ssl_non_raw_setup(char *str)
 199{
 200        opts.raw = 0;
 201        return 1;
 202}
 203__setup("ssl-non-raw", ssl_non_raw_setup);
 204__channel_help(ssl_non_raw_setup, "set serial lines to non-raw mode");
 205