diff options
Diffstat (limited to 'drivers/serial/kgdboc.c')
| -rw-r--r-- | drivers/serial/kgdboc.c | 172 |
1 files changed, 165 insertions, 7 deletions
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c index eadc1ab6bbc..25a8bc565f4 100644 --- a/drivers/serial/kgdboc.c +++ b/drivers/serial/kgdboc.c @@ -14,7 +14,11 @@ #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 @@ -29,9 +33,102 @@ static struct kparam_string kps = { .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) { @@ -45,25 +142,57 @@ static int kgdboc_option_setup(char *opt) __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(config, &tty_line); + 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; @@ -75,6 +204,7 @@ static int configure_kgdboc(void) noconfig: config[0] = 0; configured = 0; + cleanup_kgdboc(); return err; } @@ -88,20 +218,18 @@ static int __init init_kgdboc(void) return configure_kgdboc(); } -static void cleanup_kgdboc(void) -{ - if (configured == 1) - kgdb_unregister_io_module(&kgdboc_io_ops); -} - 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); } @@ -140,8 +268,14 @@ static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp) 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); @@ -152,6 +286,11 @@ 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 = { @@ -162,6 +301,25 @@ static struct kgdb_io kgdboc_io_ops = { .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); |