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path: root/drivers/serial/kgdboc.c
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Diffstat (limited to 'drivers/serial/kgdboc.c')
-rw-r--r--drivers/serial/kgdboc.c94
1 files changed, 87 insertions, 7 deletions
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index eadc1ab6bbc..a9a94ae7234 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -14,7 +14,9 @@
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/kgdb.h>
+#include <linux/kdb.h>
#include <linux/tty.h>
+#include <linux/console.h>
#define MAX_CONFIG_LEN 40
@@ -32,6 +34,40 @@ static struct kparam_string kps = {
static struct tty_driver *kgdb_tty_driver;
static int kgdb_tty_line;
+#ifdef CONFIG_KDB_KEYBOARD
+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--;
+ }
+ }
+}
+#else /* ! CONFIG_KDB_KEYBOARD */
+#define kgdboc_register_kbd(x) 0
+#define kgdboc_unregister_kbd()
+#endif /* ! CONFIG_KDB_KEYBOARD */
+
static int kgdboc_option_setup(char *opt)
{
if (strlen(opt) > MAX_CONFIG_LEN) {
@@ -45,25 +81,51 @@ 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;
- p = tty_find_polling_driver(config, &tty_line);
+ 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;
@@ -75,6 +137,7 @@ static int configure_kgdboc(void)
noconfig:
config[0] = 0;
configured = 0;
+ cleanup_kgdboc();
return err;
}
@@ -88,20 +151,18 @@ 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);
}
@@ -162,6 +223,25 @@ 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 */
+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);