From c3e6d407c0c09fb46a391bdd0a28827472825de7 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Tue, 4 Sep 2012 19:36:41 +0200
Subject: s390/scm: remove superfluous lock

Remove the spinlock from struct scm_device. drvdata and attributes
are guarded via device_lock.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/include/asm/eadm.h b/arch/s390/include/asm/eadm.h
index 4d6e103..8d48471 100644
--- a/arch/s390/include/asm/eadm.h
+++ b/arch/s390/include/asm/eadm.h
@@ -3,7 +3,6 @@
 
 #include <linux/types.h>
 #include <linux/device.h>
-#include <linux/spinlock.h>
 
 struct arqb {
 	u64 data;
@@ -83,7 +82,6 @@ struct scm_device {
 	u64 size;
 	unsigned int nr_max_block;
 	struct device dev;
-	spinlock_t lock;
 	struct {
 		unsigned int persistence:4;
 		unsigned int oper_state:4;
diff --git a/drivers/s390/block/scm_drv.c b/drivers/s390/block/scm_drv.c
index fce711a..349966f 100644
--- a/drivers/s390/block/scm_drv.c
+++ b/drivers/s390/block/scm_drv.c
@@ -9,7 +9,6 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/module.h>
-#include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <asm/eadm.h>
 #include "scm_blk.h"
@@ -37,15 +36,10 @@ static int scm_probe(struct scm_device *scmdev)
 	if (!bdev)
 		return -ENOMEM;
 
-	spin_lock_irq(&scmdev->lock);
 	dev_set_drvdata(&scmdev->dev, bdev);
-	spin_unlock_irq(&scmdev->lock);
-
 	ret = scm_blk_dev_setup(bdev, scmdev);
 	if (ret) {
-		spin_lock_irq(&scmdev->lock);
 		dev_set_drvdata(&scmdev->dev, NULL);
-		spin_unlock_irq(&scmdev->lock);
 		kfree(bdev);
 		goto out;
 	}
@@ -56,12 +50,9 @@ out:
 
 static int scm_remove(struct scm_device *scmdev)
 {
-	struct scm_blk_dev *bdev;
+	struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
 
-	spin_lock_irq(&scmdev->lock);
-	bdev = dev_get_drvdata(&scmdev->dev);
 	dev_set_drvdata(&scmdev->dev, NULL);
-	spin_unlock_irq(&scmdev->lock);
 	scm_blk_dev_cleanup(bdev);
 	kfree(bdev);
 
diff --git a/drivers/s390/cio/scm.c b/drivers/s390/cio/scm.c
index aa4476e..bcf20f3 100644
--- a/drivers/s390/cio/scm.c
+++ b/drivers/s390/cio/scm.c
@@ -5,7 +5,6 @@
  * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
  */
 
-#include <linux/spinlock.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -134,9 +133,9 @@ static ssize_t show_##name(struct device *dev,				\
 	struct scm_device *scmdev = to_scm_dev(dev);			\
 	int ret;							\
 									\
-	spin_lock(&scmdev->lock);					\
+	device_lock(dev);						\
 	ret = sprintf(buf, "%u\n", scmdev->attrs.name);			\
-	spin_unlock(&scmdev->lock);					\
+	device_unlock(dev);						\
 									\
 	return ret;							\
 }									\
@@ -193,7 +192,6 @@ static void scmdev_setup(struct scm_device *scmdev, struct sale *sale,
 	scmdev->dev.bus = &scm_bus_type;
 	scmdev->dev.release = scmdev_release;
 	scmdev->dev.groups = scmdev_attr_groups;
-	spin_lock_init(&scmdev->lock);
 }
 
 /*
-- 
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