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>

1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h
new file mode 100644
index 000000000000..5aba5612588f
--- /dev/null
+++ b/drivers/s390/block/scm_blk.h
@@ -0,0 +1,79 @@
+#ifndef SCM_BLK_H
+#define SCM_BLK_H
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/genhd.h>
+#include <linux/list.h>
+
+#include <asm/debug.h>
+#include <asm/eadm.h>
+
+#define SCM_NR_PARTS 8
+#define SCM_QUEUE_DELAY 5
+
+struct scm_blk_dev {
+	struct tasklet_struct tasklet;
+	struct request_queue *rq;
+	struct gendisk *gendisk;
+	struct scm_device *scmdev;
+	spinlock_t rq_lock;	/* guard the request queue */
+	spinlock_t lock;	/* guard the rest of the blockdev */
+	atomic_t queued_reqs;
+	struct list_head finished_requests;
+};
+
+struct scm_request {
+	struct scm_blk_dev *bdev;
+	struct request *request;
+	struct aidaw *aidaw;
+	struct aob *aob;
+	struct list_head list;
+	u8 retries;
+	int error;
+};
+
+#define to_aobrq(rq) container_of((void *) rq, struct aob_rq_header, data)
+
+int scm_blk_dev_setup(struct scm_blk_dev *, struct scm_device *);
+void scm_blk_dev_cleanup(struct scm_blk_dev *);
+void scm_blk_irq(struct scm_device *, void *, int);
+
+int scm_drv_init(void);
+void scm_drv_cleanup(void);
+
+
+extern debug_info_t *scm_debug;
+
+#define SCM_LOG(imp, txt) do {					\
+		debug_text_event(scm_debug, imp, txt);		\
+	} while (0)
+
+static inline void SCM_LOG_HEX(int level, void *data, int length)
+{
+	if (level > scm_debug->level)
+		return;
+	while (length > 0) {
+		debug_event(scm_debug, level, data, length);
+		length -= scm_debug->buf_size;
+		data += scm_debug->buf_size;
+	}
+}
+
+static inline void SCM_LOG_STATE(int level, struct scm_device *scmdev)
+{
+	struct {
+		u64 address;
+		u8 oper_state;
+		u8 rank;
+	} __packed data = {
+		.address = scmdev->address,
+		.oper_state = scmdev->attrs.oper_state,
+		.rank = scmdev->attrs.rank,
+	};
+
+	SCM_LOG_HEX(level, &data, sizeof(data));
+}
+
+#endif /* SCM_BLK_H */