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Diffstat (limited to 'drivers/s390/char/sclp_con.c')
-rw-r--r--drivers/s390/char/sclp_con.c139
1 files changed, 99 insertions, 40 deletions
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index 9a25c4bd1421..336811a77672 100644
--- a/drivers/s390/char/sclp_con.c
+++ b/drivers/s390/char/sclp_con.c
@@ -1,11 +1,9 @@
/*
- * drivers/s390/char/sclp_con.c
- * SCLP line mode console driver
+ * SCLP line mode console driver
*
- * S390 version
- * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- * Author(s): Martin Peschke <mpeschke@de.ibm.com>
- * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Copyright IBM Corp. 1999, 2009
+ * Author(s): Martin Peschke <mpeschke@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/kmod.h>
@@ -32,13 +30,14 @@ static spinlock_t sclp_con_lock;
static struct list_head sclp_con_pages;
/* List of full struct sclp_buffer structures ready for output */
static struct list_head sclp_con_outqueue;
-/* Counter how many buffers are emitted (max 1) and how many */
-/* are on the output queue. */
-static int sclp_con_buffer_count;
/* Pointer to current console buffer */
static struct sclp_buffer *sclp_conbuf;
/* Timer for delayed output of console messages */
static struct timer_list sclp_con_timer;
+/* Suspend mode flag */
+static int sclp_con_suspended;
+/* Flag that output queue is currently running */
+static int sclp_con_queue_running;
/* Output format for console messages */
static unsigned short sclp_con_columns;
@@ -53,42 +52,71 @@ sclp_conbuf_callback(struct sclp_buffer *buffer, int rc)
do {
page = sclp_unmake_buffer(buffer);
spin_lock_irqsave(&sclp_con_lock, flags);
+
/* Remove buffer from outqueue */
list_del(&buffer->list);
- sclp_con_buffer_count--;
list_add_tail((struct list_head *) page, &sclp_con_pages);
+
/* Check if there is a pending buffer on the out queue. */
buffer = NULL;
if (!list_empty(&sclp_con_outqueue))
- buffer = list_entry(sclp_con_outqueue.next,
- struct sclp_buffer, list);
+ buffer = list_first_entry(&sclp_con_outqueue,
+ struct sclp_buffer, list);
+ if (!buffer || sclp_con_suspended) {
+ sclp_con_queue_running = 0;
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ break;
+ }
spin_unlock_irqrestore(&sclp_con_lock, flags);
- } while (buffer && sclp_emit_buffer(buffer, sclp_conbuf_callback));
+ } while (sclp_emit_buffer(buffer, sclp_conbuf_callback));
}
-static void
-sclp_conbuf_emit(void)
+/*
+ * Finalize and emit first pending buffer.
+ */
+static void sclp_conbuf_emit(void)
{
struct sclp_buffer* buffer;
unsigned long flags;
- int count;
int rc;
spin_lock_irqsave(&sclp_con_lock, flags);
- buffer = sclp_conbuf;
+ if (sclp_conbuf)
+ list_add_tail(&sclp_conbuf->list, &sclp_con_outqueue);
sclp_conbuf = NULL;
- if (buffer == NULL) {
- spin_unlock_irqrestore(&sclp_con_lock, flags);
- return;
- }
- list_add_tail(&buffer->list, &sclp_con_outqueue);
- count = sclp_con_buffer_count++;
+ if (sclp_con_queue_running || sclp_con_suspended)
+ goto out_unlock;
+ if (list_empty(&sclp_con_outqueue))
+ goto out_unlock;
+ buffer = list_first_entry(&sclp_con_outqueue, struct sclp_buffer,
+ list);
+ sclp_con_queue_running = 1;
spin_unlock_irqrestore(&sclp_con_lock, flags);
- if (count)
- return;
+
rc = sclp_emit_buffer(buffer, sclp_conbuf_callback);
if (rc)
sclp_conbuf_callback(buffer, rc);
+ return;
+out_unlock:
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+}
+
+/*
+ * Wait until out queue is empty
+ */
+static void sclp_console_sync_queue(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ if (timer_pending(&sclp_con_timer))
+ del_timer_sync(&sclp_con_timer);
+ while (sclp_con_queue_running) {
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
+ sclp_sync_wait();
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ }
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
}
/*
@@ -123,6 +151,8 @@ sclp_console_write(struct console *console, const char *message,
/* make sure we have a console output buffer */
if (sclp_conbuf == NULL) {
while (list_empty(&sclp_con_pages)) {
+ if (sclp_con_suspended)
+ goto out;
spin_unlock_irqrestore(&sclp_con_lock, flags);
sclp_sync_wait();
spin_lock_irqsave(&sclp_con_lock, flags);
@@ -157,6 +187,7 @@ sclp_console_write(struct console *console, const char *message,
sclp_con_timer.expires = jiffies + HZ/10;
add_timer(&sclp_con_timer);
}
+out:
spin_unlock_irqrestore(&sclp_con_lock, flags);
}
@@ -168,30 +199,43 @@ sclp_console_device(struct console *c, int *index)
}
/*
- * 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.
+ * Make sure that all buffers will be flushed to the SCLP.
*/
static void
sclp_console_flush(void)
{
+ sclp_conbuf_emit();
+ sclp_console_sync_queue();
+}
+
+/*
+ * Resume console: If there are cached messages, emit them.
+ */
+static void sclp_console_resume(void)
+{
unsigned long flags;
+ spin_lock_irqsave(&sclp_con_lock, flags);
+ sclp_con_suspended = 0;
+ spin_unlock_irqrestore(&sclp_con_lock, flags);
sclp_conbuf_emit();
+}
+
+/*
+ * Suspend console: Set suspend flag and flush console
+ */
+static void sclp_console_suspend(void)
+{
+ unsigned long flags;
+
spin_lock_irqsave(&sclp_con_lock, flags);
- if (timer_pending(&sclp_con_timer))
- del_timer(&sclp_con_timer);
- while (sclp_con_buffer_count > 0) {
- spin_unlock_irqrestore(&sclp_con_lock, flags);
- sclp_sync_wait();
- spin_lock_irqsave(&sclp_con_lock, flags);
- }
+ sclp_con_suspended = 1;
spin_unlock_irqrestore(&sclp_con_lock, flags);
+ sclp_console_flush();
}
-static int
-sclp_console_notify(struct notifier_block *self,
- unsigned long event, void *data)
+static int sclp_console_notify(struct notifier_block *self,
+ unsigned long event, void *data)
{
sclp_console_flush();
return NOTIFY_OK;
@@ -199,7 +243,7 @@ sclp_console_notify(struct notifier_block *self,
static struct notifier_block on_panic_nb = {
.notifier_call = sclp_console_notify,
- .priority = 1,
+ .priority = SCLP_PANIC_PRIO_CLIENT,
};
static struct notifier_block on_reboot_nb = {
@@ -221,6 +265,22 @@ static struct console sclp_console =
};
/*
+ * This function is called for SCLP suspend and resume events.
+ */
+void sclp_console_pm_event(enum sclp_pm_event sclp_pm_event)
+{
+ switch (sclp_pm_event) {
+ case SCLP_PM_EVENT_FREEZE:
+ sclp_console_suspend();
+ break;
+ case SCLP_PM_EVENT_RESTORE:
+ case SCLP_PM_EVENT_THAW:
+ sclp_console_resume();
+ break;
+ }
+}
+
+/*
* called by console_init() in drivers/char/tty_io.c at boot-time.
*/
static int __init
@@ -243,7 +303,6 @@ sclp_console_init(void)
}
INIT_LIST_HEAD(&sclp_con_outqueue);
spin_lock_init(&sclp_con_lock);
- sclp_con_buffer_count = 0;
sclp_conbuf = NULL;
init_timer(&sclp_con_timer);