hvc_console: Provide (un)locked version for hvc_resize()
Rename the locking free hvc_resize() function to __hvc_resize() and
provide an inline function that locks the hvc_struct and calls
__hvc_resize().
The rationale for this patch is that virtio_console calls the hvc_resize()
function without locking the hvc_struct. So it needs to call the lock
itself.
According to naming rules, the unlocked version is renamed and
prefixed with "__".
References to unlocked function calls in hvc back-ends has been updated.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 25ce15b..a632f25 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -678,7 +678,7 @@
EXPORT_SYMBOL_GPL(hvc_poll);
/**
- * hvc_resize() - Update terminal window size information.
+ * __hvc_resize() - Update terminal window size information.
* @hp: HVC console pointer
* @ws: Terminal window size structure
*
@@ -687,12 +687,12 @@
*
* Locking: Locking free; the function MUST be called holding hp->lock
*/
-void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+void __hvc_resize(struct hvc_struct *hp, struct winsize ws)
{
hp->ws = ws;
schedule_work(&hp->tty_resize);
}
-EXPORT_SYMBOL_GPL(hvc_resize);
+EXPORT_SYMBOL_GPL(__hvc_resize);
/*
* This kthread is either polling or interrupt driven. This is determined by
diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h
index 3c85d78..10950ca 100644
--- a/drivers/char/hvc_console.h
+++ b/drivers/char/hvc_console.h
@@ -28,6 +28,7 @@
#define HVC_CONSOLE_H
#include <linux/kref.h>
#include <linux/tty.h>
+#include <linux/spinlock.h>
/*
* This is the max number of console adapters that can/will be found as
@@ -88,7 +89,16 @@
void hvc_kick(void);
/* Resize hvc tty terminal window */
-extern void hvc_resize(struct hvc_struct *hp, struct winsize ws);
+extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
+
+static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&hp->lock, flags);
+ __hvc_resize(hp, ws);
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
/* default notifier for irq based notification */
extern int notifier_add_irq(struct hvc_struct *hp, int data);
diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c
index 0ecac7e..b8a5d65 100644
--- a/drivers/char/hvc_iucv.c
+++ b/drivers/char/hvc_iucv.c
@@ -273,7 +273,9 @@
case MSG_TYPE_WINSIZE:
if (rb->mbuf->datalen != sizeof(struct winsize))
break;
- hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
+ /* The caller must ensure that the hvc is locked, which
+ * is the case when called from hvc_iucv_get_chars() */
+ __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
break;
case MSG_TYPE_ERROR: /* ignored ... */