hvc_console: Add kdb support

Add poll_get_char and poll_put_char for kdb. Enable kdb at boot with:

kgdboc=hvc0

or at runtime with:

echo hvc0 > /sys/module/kgdboc/parameters/kgdboc

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2011-07-12 19:44:05 +00:00 committed by Benjamin Herrenschmidt
parent 19df9abdd3
commit 762e77ae7d
1 changed files with 39 additions and 0 deletions

View File

@ -39,6 +39,7 @@
#include <linux/delay.h> #include <linux/delay.h>
#include <linux/freezer.h> #include <linux/freezer.h>
#include <linux/slab.h> #include <linux/slab.h>
#include <linux/serial_core.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
@ -766,6 +767,39 @@ static int hvc_tiocmset(struct tty_struct *tty,
return hp->ops->tiocmset(hp, set, clear); return hp->ops->tiocmset(hp, set, clear);
} }
#ifdef CONFIG_CONSOLE_POLL
int hvc_poll_init(struct tty_driver *driver, int line, char *options)
{
return 0;
}
static int hvc_poll_get_char(struct tty_driver *driver, int line)
{
struct tty_struct *tty = driver->ttys[0];
struct hvc_struct *hp = tty->driver_data;
int n;
char ch;
n = hp->ops->get_chars(hp->vtermno, &ch, 1);
if (n == 0)
return NO_POLL_CHAR;
return ch;
}
static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch)
{
struct tty_struct *tty = driver->ttys[0];
struct hvc_struct *hp = tty->driver_data;
int n;
do {
n = hp->ops->put_chars(hp->vtermno, &ch, 1);
} while (n <= 0);
}
#endif
static const struct tty_operations hvc_ops = { static const struct tty_operations hvc_ops = {
.open = hvc_open, .open = hvc_open,
.close = hvc_close, .close = hvc_close,
@ -776,6 +810,11 @@ static const struct tty_operations hvc_ops = {
.chars_in_buffer = hvc_chars_in_buffer, .chars_in_buffer = hvc_chars_in_buffer,
.tiocmget = hvc_tiocmget, .tiocmget = hvc_tiocmget,
.tiocmset = hvc_tiocmset, .tiocmset = hvc_tiocmset,
#ifdef CONFIG_CONSOLE_POLL
.poll_init = hvc_poll_init,
.poll_get_char = hvc_poll_get_char,
.poll_put_char = hvc_poll_put_char,
#endif
}; };
struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,