[S390] console flush on panic / reboot
The s390 console drivers use the unblank callback of the console
structure to flush the console buffer. In case of a panic or a
reboot the CPU doing the callback can block on the console i/o.
The other CPUs in the system continue to work. For panic this is
not a good idea.
Replace the unblank callback with proper panic/reboot notifier.
These get called after all but one CPU have been stopped.
Signed-off-by: Holger Smolinski <Holger.Smolinski@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index 7e619c5..9a25c4b 100644
--- a/drivers/s390/char/sclp_con.c
+++ b/drivers/s390/char/sclp_con.c
@@ -16,6 +16,7 @@
#include <linux/bootmem.h>
#include <linux/termios.h>
#include <linux/err.h>
+#include <linux/reboot.h>
#include "sclp.h"
#include "sclp_rw.h"
@@ -172,7 +173,7 @@
* will be flushed to the SCLP.
*/
static void
-sclp_console_unblank(void)
+sclp_console_flush(void)
{
unsigned long flags;
@@ -188,6 +189,24 @@
spin_unlock_irqrestore(&sclp_con_lock, flags);
}
+static int
+sclp_console_notify(struct notifier_block *self,
+ unsigned long event, void *data)
+{
+ sclp_console_flush();
+ return NOTIFY_OK;
+}
+
+static struct notifier_block on_panic_nb = {
+ .notifier_call = sclp_console_notify,
+ .priority = 1,
+};
+
+static struct notifier_block on_reboot_nb = {
+ .notifier_call = sclp_console_notify,
+ .priority = 1,
+};
+
/*
* used to register the SCLP console to the kernel and to
* give printk necessary information
@@ -197,7 +216,6 @@
.name = sclp_console_name,
.write = sclp_console_write,
.device = sclp_console_device,
- .unblank = sclp_console_unblank,
.flags = CON_PRINTBUFFER,
.index = 0 /* ttyS0 */
};
@@ -241,6 +259,8 @@
sclp_con_width_htab = 8;
/* enable printk-access to this driver */
+ atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
+ register_reboot_notifier(&on_reboot_nb);
register_console(&sclp_console);
return 0;
}