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authorHolger Smolinski <Holger.Smolinski@de.ibm.com>2008-10-10 23:33:27 +0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-10-10 23:34:01 +0400
commit2332ce1a97963b7769e0c2d40492a10a124efba5 (patch)
tree38728f02d84d91c9ce6e4bb06e871cc19cbe57cd /drivers
parent15e86b0c752d50e910b2cca6e83ce74c4440d06c (diff)
downloadlinux-2332ce1a97963b7769e0c2d40492a10a124efba5.tar.xz
[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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/s390/char/con3215.c27
-rw-r--r--drivers/s390/char/con3270.c27
-rw-r--r--drivers/s390/char/sclp_con.c24
-rw-r--r--drivers/s390/char/sclp_vt220.c26
4 files changed, 86 insertions, 18 deletions
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index d3ec9b55ab35..982cf62ab66d 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -21,6 +21,7 @@
#include <linux/console.h>
#include <linux/interrupt.h>
#include <linux/err.h>
+#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
@@ -775,11 +776,11 @@ static struct tty_driver *con3215_device(struct console *c, int *index)
}
/*
- * panic() calls console_unblank before the system enters a
- * disabled, endless loop.
+ * panic() calls con3215_flush through a panic_notifier
+ * before the system enters a disabled, endless loop.
*/
static void
-con3215_unblank(void)
+con3215_flush(void)
{
struct raw3215_info *raw;
unsigned long flags;
@@ -790,6 +791,23 @@ con3215_unblank(void)
spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
}
+static int con3215_notify(struct notifier_block *self,
+ unsigned long event, void *data)
+{
+ con3215_flush();
+ return NOTIFY_OK;
+}
+
+static struct notifier_block on_panic_nb = {
+ .notifier_call = con3215_notify,
+ .priority = 0,
+};
+
+static struct notifier_block on_reboot_nb = {
+ .notifier_call = con3215_notify,
+ .priority = 0,
+};
+
/*
* The console structure for the 3215 console
*/
@@ -797,7 +815,6 @@ static struct console con3215 = {
.name = "ttyS",
.write = con3215_write,
.device = con3215_device,
- .unblank = con3215_unblank,
.flags = CON_PRINTBUFFER,
};
@@ -859,6 +876,8 @@ con3215_init(void)
raw3215[0] = NULL;
return -ENODEV;
}
+ atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
+ register_reboot_notifier(&on_reboot_nb);
register_console(&con3215);
return 0;
}
diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c
index 3c07974886ed..d028d2ee83dd 100644
--- a/drivers/s390/char/con3270.c
+++ b/drivers/s390/char/con3270.c
@@ -15,6 +15,7 @@
#include <linux/list.h>
#include <linux/types.h>
#include <linux/err.h>
+#include <linux/reboot.h>
#include <asm/ccwdev.h>
#include <asm/cio.h>
@@ -528,11 +529,11 @@ con3270_wait_write(struct con3270 *cp)
}
/*
- * panic() calls console_unblank before the system enters a
- * disabled, endless loop.
+ * panic() calls con3270_flush through a panic_notifier
+ * before the system enters a disabled, endless loop.
*/
static void
-con3270_unblank(void)
+con3270_flush(void)
{
struct con3270 *cp;
unsigned long flags;
@@ -554,6 +555,23 @@ con3270_unblank(void)
spin_unlock_irqrestore(&cp->view.lock, flags);
}
+static int con3270_notify(struct notifier_block *self,
+ unsigned long event, void *data)
+{
+ con3270_flush();
+ return NOTIFY_OK;
+}
+
+static struct notifier_block on_panic_nb = {
+ .notifier_call = con3270_notify,
+ .priority = 0,
+};
+
+static struct notifier_block on_reboot_nb = {
+ .notifier_call = con3270_notify,
+ .priority = 0,
+};
+
/*
* The console structure for the 3270 console
*/
@@ -561,7 +579,6 @@ static struct console con3270 = {
.name = "tty3270",
.write = con3270_write,
.device = con3270_device,
- .unblank = con3270_unblank,
.flags = CON_PRINTBUFFER,
};
@@ -623,6 +640,8 @@ con3270_init(void)
condev->cline->len = 0;
con3270_create_status(condev);
condev->input = alloc_string(&condev->freemem, 80);
+ atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
+ register_reboot_notifier(&on_reboot_nb);
register_console(&con3270);
return 0;
}
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index 7e619c534bf4..9a25c4bd1421 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 @@ sclp_console_device(struct console *c, int *index)
* will be flushed to the SCLP.
*/
static void
-sclp_console_unblank(void)
+sclp_console_flush(void)
{
unsigned long flags;
@@ -188,6 +189,24 @@ sclp_console_unblank(void)
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 @@ static struct console sclp_console =
.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_console_init(void)
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;
}
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index ad51738c4261..9854f19f5e62 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -24,6 +24,8 @@
#include <linux/bootmem.h>
#include <linux/interrupt.h>
#include <linux/init.h>
+#include <linux/reboot.h>
+
#include <asm/uaccess.h>
#include "sclp.h"
@@ -743,24 +745,30 @@ sclp_vt220_con_device(struct console *c, int *index)
return sclp_vt220_driver;
}
-/*
- * This routine is called from panic when the kernel is going to give up.
- * We have to make sure that all buffers will be flushed to the SCLP.
- * Note that this function may be called from within an interrupt context.
- */
-static void
-sclp_vt220_con_unblank(void)
+static int
+sclp_vt220_notify(struct notifier_block *self,
+ unsigned long event, void *data)
{
__sclp_vt220_flush_buffer();
+ return NOTIFY_OK;
}
+static struct notifier_block on_panic_nb = {
+ .notifier_call = sclp_vt220_notify,
+ .priority = 1,
+};
+
+static struct notifier_block on_reboot_nb = {
+ .notifier_call = sclp_vt220_notify,
+ .priority = 1,
+};
+
/* Structure needed to register with printk */
static struct console sclp_vt220_console =
{
.name = SCLP_VT220_CONSOLE_NAME,
.write = sclp_vt220_con_write,
.device = sclp_vt220_con_device,
- .unblank = sclp_vt220_con_unblank,
.flags = CON_PRINTBUFFER,
.index = SCLP_VT220_CONSOLE_INDEX
};
@@ -776,6 +784,8 @@ sclp_vt220_con_init(void)
if (rc)
return rc;
/* Attach linux console */
+ atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
+ register_reboot_notifier(&on_reboot_nb);
register_console(&sclp_vt220_console);
return 0;
}