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authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>2009-08-27 01:45:39 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-09-24 15:12:47 +1000
commit254be490f257fc3f76ca5f869ac8d107b3827025 (patch)
tree8ef8b4540f54600e3f5cb0f82b7922b53b467278
parent94a8d5caba74211ec76dac80fc6e2d5c391530df (diff)
downloadop-kernel-dev-254be490f257fc3f76ca5f869ac8d107b3827025.zip
op-kernel-dev-254be490f257fc3f76ca5f869ac8d107b3827025.tar.gz
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>
-rw-r--r--drivers/char/hvc_console.c6
-rw-r--r--drivers/char/hvc_console.h12
-rw-r--r--drivers/char/hvc_iucv.c4
3 files changed, 17 insertions, 5 deletions
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 @@ int hvc_poll(struct hvc_struct *hp)
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 @@ EXPORT_SYMBOL_GPL(hvc_poll);
*
* 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 @@ int hvc_poll(struct hvc_struct *hp);
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 @@ static int hvc_iucv_write(struct hvc_iucv_private *priv,
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 ... */
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