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![Joe Perches](/assets/img/avatar_default.png)
Tyops should be fixed. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
339 lines
7.4 KiB
C
339 lines
7.4 KiB
C
/*
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* Based on the same principle as kgdboe using the NETPOLL api, this
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* driver uses a console polling api to implement a gdb serial inteface
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* which is multiplexed on a console port.
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*
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* Maintainer: Jason Wessel <jason.wessel@windriver.com>
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*
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* 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/kernel.h>
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#include <linux/ctype.h>
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#include <linux/kgdb.h>
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#include <linux/kdb.h>
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#include <linux/tty.h>
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#include <linux/console.h>
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#include <linux/vt_kern.h>
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#include <linux/input.h>
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#include <linux/module.h>
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#define MAX_CONFIG_LEN 40
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static struct kgdb_io kgdboc_io_ops;
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/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
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static int configured = -1;
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static char config[MAX_CONFIG_LEN];
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static struct kparam_string kps = {
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.string = config,
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.maxlen = MAX_CONFIG_LEN,
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};
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static int kgdboc_use_kms; /* 1 if we use kernel mode switching */
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static struct tty_driver *kgdb_tty_driver;
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static int kgdb_tty_line;
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#ifdef CONFIG_KDB_KEYBOARD
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static int kgdboc_reset_connect(struct input_handler *handler,
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struct input_dev *dev,
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const struct input_device_id *id)
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{
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input_reset_device(dev);
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/* Return an error - we do not want to bind, just to reset */
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return -ENODEV;
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}
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static void kgdboc_reset_disconnect(struct input_handle *handle)
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{
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/* We do not expect anyone to actually bind to us */
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BUG();
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}
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static const struct input_device_id kgdboc_reset_ids[] = {
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{
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.flags = INPUT_DEVICE_ID_MATCH_EVBIT,
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.evbit = { BIT_MASK(EV_KEY) },
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},
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{ }
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};
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static struct input_handler kgdboc_reset_handler = {
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.connect = kgdboc_reset_connect,
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.disconnect = kgdboc_reset_disconnect,
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.name = "kgdboc_reset",
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.id_table = kgdboc_reset_ids,
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};
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static DEFINE_MUTEX(kgdboc_reset_mutex);
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static void kgdboc_restore_input_helper(struct work_struct *dummy)
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{
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/*
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* We need to take a mutex to prevent several instances of
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* this work running on different CPUs so they don't try
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* to register again already registered handler.
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*/
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mutex_lock(&kgdboc_reset_mutex);
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if (input_register_handler(&kgdboc_reset_handler) == 0)
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input_unregister_handler(&kgdboc_reset_handler);
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mutex_unlock(&kgdboc_reset_mutex);
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}
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static DECLARE_WORK(kgdboc_restore_input_work, kgdboc_restore_input_helper);
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static void kgdboc_restore_input(void)
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{
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if (likely(system_state == SYSTEM_RUNNING))
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schedule_work(&kgdboc_restore_input_work);
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}
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static int kgdboc_register_kbd(char **cptr)
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{
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if (strncmp(*cptr, "kbd", 3) == 0 ||
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strncmp(*cptr, "kdb", 3) == 0) {
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if (kdb_poll_idx < KDB_POLL_FUNC_MAX) {
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kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char;
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kdb_poll_idx++;
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if (cptr[0][3] == ',')
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*cptr += 4;
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else
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return 1;
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}
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}
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return 0;
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}
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static void kgdboc_unregister_kbd(void)
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{
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int i;
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for (i = 0; i < kdb_poll_idx; i++) {
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if (kdb_poll_funcs[i] == kdb_get_kbd_char) {
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kdb_poll_idx--;
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kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx];
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kdb_poll_funcs[kdb_poll_idx] = NULL;
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i--;
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}
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}
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flush_work(&kgdboc_restore_input_work);
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}
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#else /* ! CONFIG_KDB_KEYBOARD */
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#define kgdboc_register_kbd(x) 0
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#define kgdboc_unregister_kbd()
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#define kgdboc_restore_input()
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#endif /* ! CONFIG_KDB_KEYBOARD */
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static int kgdboc_option_setup(char *opt)
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{
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if (strlen(opt) >= MAX_CONFIG_LEN) {
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printk(KERN_ERR "kgdboc: config string too long\n");
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return -ENOSPC;
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}
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strcpy(config, opt);
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return 0;
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}
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__setup("kgdboc=", kgdboc_option_setup);
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static void cleanup_kgdboc(void)
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{
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if (kgdb_unregister_nmi_console())
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return;
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kgdboc_unregister_kbd();
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if (configured == 1)
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kgdb_unregister_io_module(&kgdboc_io_ops);
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}
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static int configure_kgdboc(void)
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{
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struct tty_driver *p;
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int tty_line = 0;
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int err;
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char *cptr = config;
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struct console *cons;
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err = kgdboc_option_setup(config);
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if (err || !strlen(config) || isspace(config[0]))
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goto noconfig;
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err = -ENODEV;
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kgdboc_io_ops.is_console = 0;
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kgdb_tty_driver = NULL;
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kgdboc_use_kms = 0;
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if (strncmp(cptr, "kms,", 4) == 0) {
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cptr += 4;
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kgdboc_use_kms = 1;
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}
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if (kgdboc_register_kbd(&cptr))
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goto do_register;
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p = tty_find_polling_driver(cptr, &tty_line);
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if (!p)
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goto noconfig;
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cons = console_drivers;
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while (cons) {
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int idx;
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if (cons->device && cons->device(cons, &idx) == p &&
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idx == tty_line) {
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kgdboc_io_ops.is_console = 1;
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break;
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}
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cons = cons->next;
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}
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kgdb_tty_driver = p;
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kgdb_tty_line = tty_line;
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do_register:
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err = kgdb_register_io_module(&kgdboc_io_ops);
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if (err)
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goto noconfig;
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err = kgdb_register_nmi_console();
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if (err)
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goto nmi_con_failed;
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configured = 1;
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return 0;
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nmi_con_failed:
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kgdb_unregister_io_module(&kgdboc_io_ops);
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noconfig:
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kgdboc_unregister_kbd();
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config[0] = 0;
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configured = 0;
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cleanup_kgdboc();
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return err;
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}
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static int __init init_kgdboc(void)
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{
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/* Already configured? */
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if (configured == 1)
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return 0;
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return configure_kgdboc();
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}
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static int kgdboc_get_char(void)
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{
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if (!kgdb_tty_driver)
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return -1;
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return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver,
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kgdb_tty_line);
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}
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static void kgdboc_put_char(u8 chr)
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{
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if (!kgdb_tty_driver)
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return;
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kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver,
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kgdb_tty_line, chr);
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}
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static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
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{
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int len = strlen(kmessage);
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if (len >= MAX_CONFIG_LEN) {
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printk(KERN_ERR "kgdboc: config string too long\n");
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return -ENOSPC;
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}
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/* Only copy in the string if the init function has not run yet */
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if (configured < 0) {
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strcpy(config, kmessage);
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return 0;
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}
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if (kgdb_connected) {
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printk(KERN_ERR
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"kgdboc: Cannot reconfigure while KGDB is connected.\n");
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return -EBUSY;
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}
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strcpy(config, kmessage);
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/* Chop out \n char as a result of echo */
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if (config[len - 1] == '\n')
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config[len - 1] = '\0';
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if (configured == 1)
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cleanup_kgdboc();
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/* Go and configure with the new params. */
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return configure_kgdboc();
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}
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static int dbg_restore_graphics;
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static void kgdboc_pre_exp_handler(void)
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{
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if (!dbg_restore_graphics && kgdboc_use_kms) {
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dbg_restore_graphics = 1;
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con_debug_enter(vc_cons[fg_console].d);
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}
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/* Increment the module count when the debugger is active */
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if (!kgdb_connected)
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try_module_get(THIS_MODULE);
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}
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static void kgdboc_post_exp_handler(void)
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{
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/* decrement the module count when the debugger detaches */
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if (!kgdb_connected)
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module_put(THIS_MODULE);
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if (kgdboc_use_kms && dbg_restore_graphics) {
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dbg_restore_graphics = 0;
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con_debug_leave();
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}
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kgdboc_restore_input();
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}
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static struct kgdb_io kgdboc_io_ops = {
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.name = "kgdboc",
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.read_char = kgdboc_get_char,
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.write_char = kgdboc_put_char,
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.pre_exception = kgdboc_pre_exp_handler,
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.post_exception = kgdboc_post_exp_handler,
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};
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#ifdef CONFIG_KGDB_SERIAL_CONSOLE
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/* This is only available if kgdboc is a built in for early debugging */
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static int __init kgdboc_early_init(char *opt)
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{
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/* save the first character of the config string because the
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* init routine can destroy it.
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*/
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char save_ch;
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kgdboc_option_setup(opt);
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save_ch = config[0];
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init_kgdboc();
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config[0] = save_ch;
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return 0;
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}
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early_param("ekgdboc", kgdboc_early_init);
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#endif /* CONFIG_KGDB_SERIAL_CONSOLE */
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module_init(init_kgdboc);
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module_exit(cleanup_kgdboc);
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module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
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MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
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MODULE_DESCRIPTION("KGDB Console TTY Driver");
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MODULE_LICENSE("GPL");
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