s390: add scm block driver

Block device driver for Storage Class Memory (SCM). This driver
provides a block device interface for each available SCM increment.

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

drivers/s390/block/scm_drv.c

@@ -0,0 +1,90 @@
+/*
+ * Device driver for s390 storage class memory.
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Sebastian Ott <sebott@linux.vnet.ibm.com>
+ */
+
+#define KMSG_COMPONENT "scm_block"
+#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"
+
+static void notify(struct scm_device *scmdev)
+{
+	pr_info("%lu: The capabilities of the SCM increment changed\n",
+		(unsigned long) scmdev->address);
+	SCM_LOG(2, "State changed");
+	SCM_LOG_STATE(2, scmdev);
+}
+
+static int scm_probe(struct scm_device *scmdev)
+{
+	struct scm_blk_dev *bdev;
+	int ret;
+
+	SCM_LOG(2, "probe");
+	SCM_LOG_STATE(2, scmdev);
+
+	if (scmdev->attrs.oper_state != OP_STATE_GOOD)
+		return -EINVAL;
+
+	bdev = kzalloc(sizeof(*bdev), GFP_KERNEL);
+	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;
+	}
+
+out:
+	return ret;
+}
+
+static int scm_remove(struct scm_device *scmdev)
+{
+	struct scm_blk_dev *bdev;
+
+	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);
+
+	return 0;
+}
+
+static struct scm_driver scm_drv = {
+	.drv = {
+		.name = "scm_block",
+		.owner = THIS_MODULE,
+	},
+	.notify = notify,
+	.probe = scm_probe,
+	.remove = scm_remove,
+	.handler = scm_blk_irq,
+};
+
+int __init scm_drv_init(void)
+{
+	return scm_driver_register(&scm_drv);
+}
+
+void scm_drv_cleanup(void)
+{
+	scm_driver_unregister(&scm_drv);
+}