This reverts commit 0c57dfcc6c1d037243c2f8fbf62eab3633326ec0.
The functionality was supoosed to be used by a later patch in the
series that never landed [1]. Drop it.
NOTE: part of functionality was already reverted by commit
39d0be87438a ("serial: kgdb_nmi: Remove unused knock code"). Also note
that this revert is not a clean revert given code changes that have
happened in the meantime.
It's obvious that nobody is using this code since the two exposed
functions (kgdb_register_nmi_console() and
kgdb_unregister_nmi_console()) are both no-ops if
"arch_kgdb_ops.enable_nmi" is not defined. No architectures define it.
[1] https://lore.kernel.org/lkml/1348522080-32629-9-git-send-email-anton.vorontsov@xxxxxxxxxx/
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
drivers/tty/serial/Kconfig | 19 ---
drivers/tty/serial/Makefile | 1 -
drivers/tty/serial/kgdb_nmi.c | 280 ----------------------------------
drivers/tty/serial/kgdboc.c | 8 -
include/linux/kgdb.h | 8 -
5 files changed, 316 deletions(-)
delete mode 100644 drivers/tty/serial/kgdb_nmi.c
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 976dae3bb1bb..f21cad6aaa47 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -179,25 +179,6 @@ config SERIAL_ATMEL_TTYAT
Say Y if you have an external 8250/16C550 UART. If unsure, say N.
-config SERIAL_KGDB_NMI
- bool "Serial console over KGDB NMI debugger port"
- depends on KGDB_SERIAL_CONSOLE
- help
- This special driver allows you to temporary use NMI debugger port
- as a normal console (assuming that the port is attached to KGDB).
-
- Unlike KDB's disable_nmi command, with this driver you are always
- able to go back to the debugger using KGDB escape sequence ($3#33).
- This is because this console driver processes the input in NMI
- context, and thus is able to intercept the magic sequence.
-
- Note that since the console interprets input and uses polling
- communication methods, for things like PPP you still must fully
- detach debugger port from the KGDB NMI (i.e. disable_nmi), and
- use raw console.
-
- If unsure, say N.
-
config SERIAL_MESON
tristate "Meson serial port support"
depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 6ff74f0a9530..3019260d9120 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -96,6 +96,5 @@ obj-$(CONFIG_SERIAL_ZS) += zs.o
# GPIOLIB helpers for modem control lines
obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
-obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
deleted file mode 100644
index 2833708e369f..000000000000
--- a/drivers/tty/serial/kgdb_nmi.c
+++ /dev/null
@@ -1,280 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * KGDB NMI serial console
- *
- * Copyright 2010 Google, Inc.
- * Arve Hjønnevåg <arve@xxxxxxxxxxx>
- * Colin Cross <ccross@xxxxxxxxxxx>
- * Copyright 2012 Linaro Ltd.
- * Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/compiler.h>
-#include <linux/slab.h>
-#include <linux/errno.h>
-#include <linux/atomic.h>
-#include <linux/console.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <linux/serial_core.h>
-#include <linux/interrupt.h>
-#include <linux/hrtimer.h>
-#include <linux/tick.h>
-#include <linux/kfifo.h>
-#include <linux/kgdb.h>
-#include <linux/kdb.h>
-
-static atomic_t kgdb_nmi_num_readers = ATOMIC_INIT(0);
-
-static int kgdb_nmi_console_setup(struct console *co, char *options)
-{
- arch_kgdb_ops.enable_nmi(1);
-
- /* 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->cons = co;
-
- return 0;
-}
-
-static void kgdb_nmi_console_write(struct console *co, const char *s, uint c)
-{
- int i;
-
- for (i = 0; i < c; i++)
- dbg_io_ops->write_char(s[i]);
-}
-
-static struct tty_driver *kgdb_nmi_tty_driver;
-
-static struct tty_driver *kgdb_nmi_console_device(struct console *co, int *idx)
-{
- *idx = co->index;
- return kgdb_nmi_tty_driver;
-}
-
-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,
- .index = -1,
-};
-
-/*
- * This is usually the maximum rate on debug ports. We make fifo large enough
- * to make copy-pasting to the terminal usable.
- */
-#define KGDB_NMI_BAUD 115200
-#define KGDB_NMI_FIFO_SIZE roundup_pow_of_two(KGDB_NMI_BAUD / 8 / HZ)
-
-struct kgdb_nmi_tty_priv {
- struct tty_port port;
- struct timer_list timer;
- STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo;
-};
-
-static struct tty_port *kgdb_nmi_port;
-
-/*
- * The tasklet is cheap, it does not cause wakeups when reschedules itself,
- * instead it waits for the next tick.
- */
-static void kgdb_nmi_tty_receiver(struct timer_list *t)
-{
- struct kgdb_nmi_tty_priv *priv = from_timer(priv, t, timer);
- char ch;
-
- priv->timer.expires = jiffies + (HZ/100);
- add_timer(&priv->timer);
-
- if (likely(!atomic_read(&kgdb_nmi_num_readers) ||
- !kfifo_len(&priv->fifo)))
- return;
-
- while (kfifo_out(&priv->fifo, &ch, 1))
- tty_insert_flip_char(&priv->port, ch, TTY_NORMAL);
- tty_flip_buffer_push(&priv->port);
-}
-
-static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)
-{
- struct kgdb_nmi_tty_priv *priv =
- container_of(port, struct kgdb_nmi_tty_priv, port);
-
- kgdb_nmi_port = port;
- 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 =
- container_of(port, struct kgdb_nmi_tty_priv, port);
-
- del_timer(&priv->timer);
- kgdb_nmi_port = NULL;
-}
-
-static const struct tty_port_operations kgdb_nmi_tty_port_ops = {
- .activate = kgdb_nmi_tty_activate,
- .shutdown = kgdb_nmi_tty_shutdown,
-};
-
-static int kgdb_nmi_tty_install(struct tty_driver *drv, struct tty_struct *tty)
-{
- struct kgdb_nmi_tty_priv *priv;
- int ret;
-
- priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
-
- INIT_KFIFO(priv->fifo);
- timer_setup(&priv->timer, kgdb_nmi_tty_receiver, 0);
- tty_port_init(&priv->port);
- priv->port.ops = &kgdb_nmi_tty_port_ops;
- tty->driver_data = priv;
-
- ret = tty_port_install(&priv->port, drv, tty);
- if (ret) {
- pr_err("%s: can't install tty port: %d\n", __func__, ret);
- goto err;
- }
- return 0;
-err:
- tty_port_destroy(&priv->port);
- kfree(priv);
- return ret;
-}
-
-static void kgdb_nmi_tty_cleanup(struct tty_struct *tty)
-{
- struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-
- tty->driver_data = NULL;
- tty_port_destroy(&priv->port);
- kfree(priv);
-}
-
-static int kgdb_nmi_tty_open(struct tty_struct *tty, struct file *file)
-{
- struct kgdb_nmi_tty_priv *priv = tty->driver_data;
- unsigned int mode = file->f_flags & O_ACCMODE;
- int ret;
-
- ret = tty_port_open(&priv->port, tty, file);
- if (!ret && (mode == O_RDONLY || mode == O_RDWR))
- atomic_inc(&kgdb_nmi_num_readers);
-
- return ret;
-}
-
-static void kgdb_nmi_tty_close(struct tty_struct *tty, struct file *file)
-{
- struct kgdb_nmi_tty_priv *priv = tty->driver_data;
- unsigned int mode = file->f_flags & O_ACCMODE;
-
- if (mode == O_RDONLY || mode == O_RDWR)
- atomic_dec(&kgdb_nmi_num_readers);
-
- tty_port_close(&priv->port, tty, file);
-}
-
-static void kgdb_nmi_tty_hangup(struct tty_struct *tty)
-{
- struct kgdb_nmi_tty_priv *priv = tty->driver_data;
-
- tty_port_hangup(&priv->port);
-}
-
-static unsigned int kgdb_nmi_tty_write_room(struct tty_struct *tty)
-{
- /* Actually, we can handle any amount as we use polled writes. */
- return 2048;
-}
-
-static ssize_t kgdb_nmi_tty_write(struct tty_struct *tty, const u8 *buf,
- size_t c)
-{
- int i;
-
- for (i = 0; i < c; i++)
- dbg_io_ops->write_char(buf[i]);
- return c;
-}
-
-static const struct tty_operations kgdb_nmi_tty_ops = {
- .open = kgdb_nmi_tty_open,
- .close = kgdb_nmi_tty_close,
- .install = kgdb_nmi_tty_install,
- .cleanup = kgdb_nmi_tty_cleanup,
- .hangup = kgdb_nmi_tty_hangup,
- .write_room = kgdb_nmi_tty_write_room,
- .write = kgdb_nmi_tty_write,
-};
-
-int kgdb_register_nmi_console(void)
-{
- int ret;
-
- if (!arch_kgdb_ops.enable_nmi)
- return 0;
-
- kgdb_nmi_tty_driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
- if (IS_ERR(kgdb_nmi_tty_driver)) {
- pr_err("%s: cannot allocate tty\n", __func__);
- return PTR_ERR(kgdb_nmi_tty_driver);
- }
- kgdb_nmi_tty_driver->driver_name = "ttyNMI";
- kgdb_nmi_tty_driver->name = "ttyNMI";
- kgdb_nmi_tty_driver->num = 1;
- kgdb_nmi_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
- kgdb_nmi_tty_driver->subtype = SERIAL_TYPE_NORMAL;
- kgdb_nmi_tty_driver->init_termios = tty_std_termios;
- tty_termios_encode_baud_rate(&kgdb_nmi_tty_driver->init_termios,
- KGDB_NMI_BAUD, KGDB_NMI_BAUD);
- tty_set_operations(kgdb_nmi_tty_driver, &kgdb_nmi_tty_ops);
-
- ret = tty_register_driver(kgdb_nmi_tty_driver);
- if (ret) {
- pr_err("%s: can't register tty driver: %d\n", __func__, ret);
- goto err_drv_reg;
- }
-
- register_console(&kgdb_nmi_console);
-
- return 0;
-err_drv_reg:
- tty_driver_kref_put(kgdb_nmi_tty_driver);
- return ret;
-}
-EXPORT_SYMBOL_GPL(kgdb_register_nmi_console);
-
-int kgdb_unregister_nmi_console(void)
-{
- int ret;
-
- if (!arch_kgdb_ops.enable_nmi)
- return 0;
- arch_kgdb_ops.enable_nmi(0);
-
- ret = unregister_console(&kgdb_nmi_console);
- if (ret)
- return ret;
-
- tty_unregister_driver(kgdb_nmi_tty_driver);
- tty_driver_kref_put(kgdb_nmi_tty_driver);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(kgdb_unregister_nmi_console);
diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 58ea1e1391ce..85f6c5a76e0f 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -186,8 +186,6 @@ static void cleanup_kgdboc(void)
if (configured != 1)
return;
- if (kgdb_unregister_nmi_console())
- return;
kgdboc_unregister_kbd();
kgdb_unregister_io_module(&kgdboc_io_ops);
}
@@ -250,16 +248,10 @@ static int configure_kgdboc(void)
if (err)
goto noconfig;
- err = kgdb_register_nmi_console();
- if (err)
- goto nmi_con_failed;
-
configured = 1;
return 0;
-nmi_con_failed:
- kgdb_unregister_io_module(&kgdboc_io_ops);
noconfig:
kgdboc_unregister_kbd();
configured = 0;
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index 51ef131e66b7..14739952698b 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -306,14 +306,6 @@ extern const struct kgdb_arch arch_kgdb_ops;
extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);
-#ifdef CONFIG_SERIAL_KGDB_NMI
-extern int kgdb_register_nmi_console(void);
-extern int kgdb_unregister_nmi_console(void);
-#else
-static inline int kgdb_register_nmi_console(void) { return 0; }
-static inline int kgdb_unregister_nmi_console(void) { return 0; }
-#endif
-
extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
extern struct kgdb_io *dbg_io_ops;
--
2.48.1.262.g85cc9f2d1e-goog
