diff options
Diffstat (limited to 'drivers/tty/serial/kgdb_nmi.c')
| -rw-r--r-- | drivers/tty/serial/kgdb_nmi.c | 60 |
1 files changed, 27 insertions, 33 deletions
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c index 5dafcf1c227..cfadf2971b1 100644 --- a/drivers/tty/serial/kgdb_nmi.c +++ b/drivers/tty/serial/kgdb_nmi.c @@ -15,7 +15,6 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/compiler.h> -#include <linux/init.h> #include <linux/slab.h> #include <linux/errno.h> #include <linux/atomic.h> @@ -45,13 +44,22 @@ MODULE_PARM_DESC(magic, "magic sequence to enter NMI debugger (default $3#33)"); static bool kgdb_nmi_tty_enabled; +static int kgdb_nmi_console_setup(struct console *co, char *options) +{ + /* The NMI console uses the dbg_io_ops to issue console messages. To + * avoid duplicate messages during kdb sessions we must inform kdb's + * I/O utilities that messages sent to the console will automatically + * be displayed on the dbg_io. + */ + dbg_io_ops->is_console = true; + + return 0; +} + static void kgdb_nmi_console_write(struct console *co, const char *s, uint c) { int i; - if (!kgdb_nmi_tty_enabled || atomic_read(&kgdb_active) >= 0) - return; - for (i = 0; i < c; i++) dbg_io_ops->write_char(s[i]); } @@ -66,6 +74,7 @@ static struct tty_driver *kgdb_nmi_console_device(struct console *co, int *idx) static struct console kgdb_nmi_console = { .name = "ttyNMI", + .setup = kgdb_nmi_console_setup, .write = kgdb_nmi_console_write, .device = kgdb_nmi_console_device, .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED, @@ -81,29 +90,10 @@ static struct console kgdb_nmi_console = { struct kgdb_nmi_tty_priv { struct tty_port port; - struct tasklet_struct tlet; + struct timer_list timer; STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo; }; -static struct kgdb_nmi_tty_priv *kgdb_nmi_port_to_priv(struct tty_port *port) -{ - return container_of(port, struct kgdb_nmi_tty_priv, port); -} - -/* - * Our debugging console is polled in a tasklet, so we'll check for input - * every tick. In HZ-less mode, we should program the next tick. We have - * to use the lowlevel stuff as no locks should be grabbed. - */ -#ifdef CONFIG_HIGH_RES_TIMERS -static void kgdb_tty_poke(void) -{ - tick_program_event(ktime_get(), 0); -} -#else -static inline void kgdb_tty_poke(void) {} -#endif - static struct tty_port *kgdb_nmi_port; static void kgdb_tty_recv(int ch) @@ -114,14 +104,13 @@ static void kgdb_tty_recv(int ch) if (!kgdb_nmi_port || ch < 0) return; /* - * Can't use port->tty->driver_data as tty might be not there. Tasklet + * Can't use port->tty->driver_data as tty might be not there. Timer * will check for tty and will get the ref, but here we don't have to * do that, and actually, we can't: we're in NMI context, no locks are * possible. */ - priv = kgdb_nmi_port_to_priv(kgdb_nmi_port); + priv = container_of(kgdb_nmi_port, struct kgdb_nmi_tty_priv, port); kfifo_in(&priv->fifo, &c, 1); - kgdb_tty_poke(); } static int kgdb_nmi_poll_one_knock(void) @@ -205,7 +194,8 @@ static void kgdb_nmi_tty_receiver(unsigned long data) struct kgdb_nmi_tty_priv *priv = (void *)data; char ch; - tasklet_schedule(&priv->tlet); + priv->timer.expires = jiffies + (HZ/100); + add_timer(&priv->timer); if (likely(!kgdb_nmi_tty_enabled || !kfifo_len(&priv->fifo))) return; @@ -217,18 +207,22 @@ static void kgdb_nmi_tty_receiver(unsigned long data) static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty) { - struct kgdb_nmi_tty_priv *priv = tty->driver_data; + struct kgdb_nmi_tty_priv *priv = + container_of(port, struct kgdb_nmi_tty_priv, port); kgdb_nmi_port = port; - tasklet_schedule(&priv->tlet); + priv->timer.expires = jiffies + (HZ/100); + add_timer(&priv->timer); + return 0; } static void kgdb_nmi_tty_shutdown(struct tty_port *port) { - struct kgdb_nmi_tty_priv *priv = port->tty->driver_data; + struct kgdb_nmi_tty_priv *priv = + container_of(port, struct kgdb_nmi_tty_priv, port); - tasklet_kill(&priv->tlet); + del_timer(&priv->timer); kgdb_nmi_port = NULL; } @@ -247,7 +241,7 @@ static int kgdb_nmi_tty_install(struct tty_driver *drv, struct tty_struct *tty) return -ENOMEM; INIT_KFIFO(priv->fifo); - tasklet_init(&priv->tlet, kgdb_nmi_tty_receiver, (unsigned long)priv); + setup_timer(&priv->timer, kgdb_nmi_tty_receiver, (unsigned long)priv); tty_port_init(&priv->port); priv->port.ops = &kgdb_nmi_tty_port_ops; tty->driver_data = priv; |