Merge commit 'v2.6.38-rc2' into topic/misc

1 files changed, 328 insertions, 0 deletions

diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
new file mode 100644
index 000000000000..25a8bc565f40
--- /dev/null
+++ b/drivers/tty/serial/kgdboc.c
@@ -0,0 +1,328 @@
+/*
+ * Based on the same principle as kgdboe using the NETPOLL api, this
+ * driver uses a console polling api to implement a gdb serial inteface
+ * which is multiplexed on a console port.
+ *
+ * Maintainer: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * 2007-2008 (c) Jason Wessel - Wind River Systems, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/kgdb.h>
+#include <linux/kdb.h>
+#include <linux/tty.h>
+#include <linux/console.h>
+#include <linux/vt_kern.h>
+#include <linux/input.h>
+
+#define MAX_CONFIG_LEN          40
+
+static struct kgdb_io           kgdboc_io_ops;
+
+/* -1 = init not run yet, 0 = unconfigured, 1 = configured. */
+static int configured           = -1;
+
+static char config[MAX_CONFIG_LEN];
+static struct kparam_string kps = {
+        .string                 = config,
+        .maxlen                 = MAX_CONFIG_LEN,
+};
+
+static int kgdboc_use_kms;  /* 1 if we use kernel mode switching */
+static struct tty_driver        *kgdb_tty_driver;
+static int                      kgdb_tty_line;
+
+#ifdef CONFIG_KDB_KEYBOARD
+static int kgdboc_reset_connect(struct input_handler *handler,
+                                struct input_dev *dev,
+                                const struct input_device_id *id)
+{
+        input_reset_device(dev);
+
+        /* Retrun an error - we do not want to bind, just to reset */
+        return -ENODEV;
+}
+
+static void kgdboc_reset_disconnect(struct input_handle *handle)
+{
+        /* We do not expect anyone to actually bind to us */
+        BUG();
+}
+
+static const struct input_device_id kgdboc_reset_ids[] = {
+        {
+                .flags = INPUT_DEVICE_ID_MATCH_EVBIT,
+                .evbit = { BIT_MASK(EV_KEY) },
+        },
+        { }
+};
+
+static struct input_handler kgdboc_reset_handler = {
+        .connect        = kgdboc_reset_connect,
+        .disconnect     = kgdboc_reset_disconnect,
+        .name           = "kgdboc_reset",
+        .id_table       = kgdboc_reset_ids,
+};
+
+static DEFINE_MUTEX(kgdboc_reset_mutex);
+
+static void kgdboc_restore_input_helper(struct work_struct *dummy)
+{
+        /*
+         * We need to take a mutex to prevent several instances of
+         * this work running on different CPUs so they don't try
+         * to register again already registered handler.
+         */
+        mutex_lock(&kgdboc_reset_mutex);
+
+        if (input_register_handler(&kgdboc_reset_handler) == 0)
+                input_unregister_handler(&kgdboc_reset_handler);
+
+        mutex_unlock(&kgdboc_reset_mutex);
+}
+
+static DECLARE_WORK(kgdboc_restore_input_work, kgdboc_restore_input_helper);
+
+static void kgdboc_restore_input(void)
+{
+        if (likely(system_state == SYSTEM_RUNNING))
+                schedule_work(&kgdboc_restore_input_work);
+}
+
+static int kgdboc_register_kbd(char **cptr)
+{
+        if (strncmp(*cptr, "kbd", 3) == 0) {
+                if (kdb_poll_idx < KDB_POLL_FUNC_MAX) {
+                        kdb_poll_funcs[kdb_poll_idx] = kdb_get_kbd_char;
+                        kdb_poll_idx++;
+                        if (cptr[0][3] == ',')
+                                *cptr += 4;
+                        else
+                                return 1;
+                }
+        }
+        return 0;
+}
+
+static void kgdboc_unregister_kbd(void)
+{
+        int i;
+
+        for (i = 0; i < kdb_poll_idx; i++) {
+                if (kdb_poll_funcs[i] == kdb_get_kbd_char) {
+                        kdb_poll_idx--;
+                        kdb_poll_funcs[i] = kdb_poll_funcs[kdb_poll_idx];
+                        kdb_poll_funcs[kdb_poll_idx] = NULL;
+                        i--;
+                }
+        }
+        flush_work_sync(&kgdboc_restore_input_work);
+}
+#else /* ! CONFIG_KDB_KEYBOARD */
+#define kgdboc_register_kbd(x) 0
+#define kgdboc_unregister_kbd()
+#define kgdboc_restore_input()
+#endif /* ! CONFIG_KDB_KEYBOARD */
+
+static int kgdboc_option_setup(char *opt)
+{
+        if (strlen(opt) > MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdboc: config string too long\n");
+                return -ENOSPC;
+        }
+        strcpy(config, opt);
+
+        return 0;
+}
+
+__setup("kgdboc=", kgdboc_option_setup);
+
+static void cleanup_kgdboc(void)
+{
+        kgdboc_unregister_kbd();
+        if (configured == 1)
+                kgdb_unregister_io_module(&kgdboc_io_ops);
+}
+
+static int configure_kgdboc(void)
+{
+        struct tty_driver *p;
+        int tty_line = 0;
+        int err;
+        char *cptr = config;
+        struct console *cons;
+
+        err = kgdboc_option_setup(config);
+        if (err || !strlen(config) || isspace(config[0]))
+                goto noconfig;
+
+        err = -ENODEV;
+        kgdboc_io_ops.is_console = 0;
+        kgdb_tty_driver = NULL;
+
+        kgdboc_use_kms = 0;
+        if (strncmp(cptr, "kms,", 4) == 0) {
+                cptr += 4;
+                kgdboc_use_kms = 1;
+        }
+
+        if (kgdboc_register_kbd(&cptr))
+                goto do_register;
+
+        p = tty_find_polling_driver(cptr, &tty_line);
+        if (!p)
+                goto noconfig;
+
+        cons = console_drivers;
+        while (cons) {
+                int idx;
+                if (cons->device && cons->device(cons, &idx) == p &&
+                    idx == tty_line) {
+                        kgdboc_io_ops.is_console = 1;
+                        break;
+                }
+                cons = cons->next;
+        }
+
+        kgdb_tty_driver = p;
+        kgdb_tty_line = tty_line;
+
+do_register:
+        err = kgdb_register_io_module(&kgdboc_io_ops);
+        if (err)
+                goto noconfig;
+
+        configured = 1;
+
+        return 0;
+
+noconfig:
+        config[0] = 0;
+        configured = 0;
+        cleanup_kgdboc();
+
+        return err;
+}
+
+static int __init init_kgdboc(void)
+{
+        /* Already configured? */
+        if (configured == 1)
+                return 0;
+
+        return configure_kgdboc();
+}
+
+static int kgdboc_get_char(void)
+{
+        if (!kgdb_tty_driver)
+                return -1;
+        return kgdb_tty_driver->ops->poll_get_char(kgdb_tty_driver,
+                                                kgdb_tty_line);
+}
+
+static void kgdboc_put_char(u8 chr)
+{
+        if (!kgdb_tty_driver)
+                return;
+        kgdb_tty_driver->ops->poll_put_char(kgdb_tty_driver,
+                                        kgdb_tty_line, chr);
+}
+
+static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
+{
+        int len = strlen(kmessage);
+
+        if (len >= MAX_CONFIG_LEN) {
+                printk(KERN_ERR "kgdboc: config string too long\n");
+                return -ENOSPC;
+        }
+
+        /* Only copy in the string if the init function has not run yet */
+        if (configured < 0) {
+                strcpy(config, kmessage);
+                return 0;
+        }
+
+        if (kgdb_connected) {
+                printk(KERN_ERR
+                       "kgdboc: Cannot reconfigure while KGDB is connected.\n");
+
+                return -EBUSY;
+        }
+
+        strcpy(config, kmessage);
+        /* Chop out \n char as a result of echo */
+        if (config[len - 1] == '\n')
+                config[len - 1] = '\0';
+
+        if (configured == 1)
+                cleanup_kgdboc();
+
+        /* Go and configure with the new params. */
+        return configure_kgdboc();
+}
+
+static int dbg_restore_graphics;
+
+static void kgdboc_pre_exp_handler(void)
+{
+        if (!dbg_restore_graphics && kgdboc_use_kms) {
+                dbg_restore_graphics = 1;
+                con_debug_enter(vc_cons[fg_console].d);
+        }
+        /* Increment the module count when the debugger is active */
+        if (!kgdb_connected)
+                try_module_get(THIS_MODULE);
+}
+
+static void kgdboc_post_exp_handler(void)
+{
+        /* decrement the module count when the debugger detaches */
+        if (!kgdb_connected)
+                module_put(THIS_MODULE);
+        if (kgdboc_use_kms && dbg_restore_graphics) {
+                dbg_restore_graphics = 0;
+                con_debug_leave();
+        }
+        kgdboc_restore_input();
+}
+
+static struct kgdb_io kgdboc_io_ops = {
+        .name                   = "kgdboc",
+        .read_char              = kgdboc_get_char,
+        .write_char             = kgdboc_put_char,
+        .pre_exception          = kgdboc_pre_exp_handler,
+        .post_exception         = kgdboc_post_exp_handler,
+};
+
+#ifdef CONFIG_KGDB_SERIAL_CONSOLE
+/* This is only available if kgdboc is a built in for early debugging */
+static int __init kgdboc_early_init(char *opt)
+{
+        /* save the first character of the config string because the
+         * init routine can destroy it.
+         */
+        char save_ch;
+
+        kgdboc_option_setup(opt);
+        save_ch = config[0];
+        init_kgdboc();
+        config[0] = save_ch;
+        return 0;
+}
+
+early_param("ekgdboc", kgdboc_early_init);
+#endif /* CONFIG_KGDB_SERIAL_CONSOLE */
+
+module_init(init_kgdboc);
+module_exit(cleanup_kgdboc);
+module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644);
+MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]");
+MODULE_DESCRIPTION("KGDB Console TTY Driver");
+MODULE_LICENSE("GPL");