[SCSI] zfcp: Move sbale handling to zfcp_qdio files

Move the code accessing the qdio sbales and zfcp_qdio_req struct to
the zfcp_qdio files and provide helper functions for accessing the
qdio related parts.
Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/s390/scsi/zfcp_def.h

@@ -44,23 +44,6 @@ struct zfcp_reqlist;
 /********************* SCSI SPECIFIC DEFINES *********************************/
 #define ZFCP_SCSI_ER_TIMEOUT                    (10*HZ)
 
-/********************* CIO/QDIO SPECIFIC DEFINES *****************************/
-
-/* DMQ bug workaround: don't use last SBALE */
-#define ZFCP_MAX_SBALES_PER_SBAL	(QDIO_MAX_ELEMENTS_PER_BUFFER - 1)
-
-/* index of last SBALE (with respect to DMQ bug workaround) */
-#define ZFCP_LAST_SBALE_PER_SBAL	(ZFCP_MAX_SBALES_PER_SBAL - 1)
-
-/* max. number of (data buffer) SBALEs in largest SBAL chain */
-#define ZFCP_MAX_SBALES_PER_REQ		\
-	(FSF_MAX_SBALS_PER_REQ * ZFCP_MAX_SBALES_PER_SBAL - 2)
-        /* request ID + QTCB in SBALE 0 + 1 of first SBAL in chain */
-
-#define ZFCP_MAX_SECTORS (ZFCP_MAX_SBALES_PER_REQ * 8)
-        /* max. number of (data buffer) SBALEs in largest SBAL chain
-           multiplied with number of sectors per 4k block */
-
 /********************* FSF SPECIFIC DEFINES *********************************/
 
 /* ATTENTION: value must not be used by hardware */

drivers/s390/scsi/zfcp_ext.h

@@ -3,7 +3,7 @@
  *
  * External function declarations.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #ifndef ZFCP_EXT_H
@@ -144,8 +144,7 @@ extern void zfcp_fsf_reqid_check(struct zfcp_qdio *, int);
 extern int zfcp_qdio_setup(struct zfcp_adapter *);
 extern void zfcp_qdio_destroy(struct zfcp_qdio *);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
-extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *,
-				   struct zfcp_qdio_req *, unsigned long,
+extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
 				   struct scatterlist *, int);
 extern int zfcp_qdio_open(struct zfcp_qdio *);
 extern void zfcp_qdio_close(struct zfcp_qdio *);

drivers/s390/scsi/zfcp_fsf.h

@@ -3,7 +3,7 @@
  *
  * Interface to the FSF support functions.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #ifndef FSF_H
@@ -152,7 +152,12 @@
 #define FSF_CLASS_3				0x00000003
 
 /* SBAL chaining */
-#define FSF_MAX_SBALS_PER_REQ			36
+#define ZFCP_FSF_MAX_SBALS_PER_REQ		36
+
+/* max. number of (data buffer) SBALEs in largest SBAL chain
+ * request ID + QTCB in SBALE 0 + 1 of first SBAL in chain   */
+#define ZFCP_FSF_MAX_SBALES_PER_REQ	\
+	(ZFCP_FSF_MAX_SBALS_PER_REQ * ZFCP_QDIO_MAX_SBALES_PER_SBAL - 2)
 
 /* logging space behind QTCB */
 #define FSF_QTCB_LOG_SIZE			1024

drivers/s390/scsi/zfcp_qdio.c

@@ -3,7 +3,7 @@
  *
  * Setup and helper functions to access QDIO.
  *
- * Copyright IBM Corporation 2002, 2009
+ * Copyright IBM Corporation 2002, 2010
  */
 
 #define KMSG_COMPONENT "zfcp"
@@ -151,8 +151,7 @@ static void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
 }
 
 static struct qdio_buffer_element *
-zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-		     unsigned long sbtype)
+zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
 	struct qdio_buffer_element *sbale;
 
@@ -180,17 +179,16 @@ zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 
 	/* set storage-block type for new SBAL */
 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
-	sbale->flags |= sbtype;
+	sbale->flags |= q_req->sbtype;
 
 	return sbale;
 }
 
 static struct qdio_buffer_element *
-zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-		     unsigned int sbtype)
+zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 {
-	if (q_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
-		return zfcp_qdio_sbal_chain(qdio, q_req, sbtype);
+	if (q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL)
+		return zfcp_qdio_sbal_chain(qdio, q_req);
 	q_req->sbale_curr++;
 	return zfcp_qdio_sbale_curr(qdio, q_req);
 }
@@ -208,15 +206,14 @@ static void zfcp_qdio_undo_sbals(struct zfcp_qdio *qdio,
 
 /**
  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
- * @fsf_req: request to be processed
- * @sbtype: SBALE flags
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_qdio_req
  * @sg: scatter-gather list
  * @max_sbals: upper bound for number of SBALs to be used
  * Returns: number of bytes, or error (negativ)
  */
 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
-			    unsigned long sbtype, struct scatterlist *sg,
-			    int max_sbals)
+			    struct scatterlist *sg, int max_sbals)
 {
 	struct qdio_buffer_element *sbale;
 	int bytes = 0;
@@ -226,10 +223,10 @@ int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
 
 	/* set storage-block type for this request */
 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
-	sbale->flags |= sbtype;
+	sbale->flags |= q_req->sbtype;
 
 	for (; sg; sg = sg_next(sg)) {
-		sbale = zfcp_qdio_sbale_next(qdio, q_req, sbtype);
+		sbale = zfcp_qdio_sbale_next(qdio, q_req);
 		if (!sbale) {
 			atomic_inc(&qdio->req_q_full);
 			zfcp_qdio_undo_sbals(qdio, q_req);

drivers/s390/scsi/zfcp_qdio.h

@@ -13,6 +13,12 @@
 
 #define ZFCP_QDIO_SBALE_LEN	PAGE_SIZE
 
+/* DMQ bug workaround: don't use last SBALE */
+#define ZFCP_QDIO_MAX_SBALES_PER_SBAL	(QDIO_MAX_ELEMENTS_PER_BUFFER - 1)
+
+/* index of last SBALE (with respect to DMQ bug workaround) */
+#define ZFCP_QDIO_LAST_SBALE_PER_SBAL	(ZFCP_QDIO_MAX_SBALES_PER_SBAL - 1)
+
 /**
  * struct zfcp_qdio_queue - qdio queue buffer, zfcp index and free count
  * @sbal: qdio buffers
@@ -51,6 +57,7 @@ struct zfcp_qdio {
 
 /**
  * struct zfcp_qdio_req - qdio queue related values for a request
+ * @sbtype: sbal type flags for sbale 0
  * @sbal_number: number of free sbals
  * @sbal_first: first sbal for this request
  * @sbal_last: last sbal for this request
@@ -61,6 +68,7 @@ struct zfcp_qdio {
  * @qdio_inb_usage: usage of inbound queue
  */
 struct zfcp_qdio_req {
+	u32	sbtype;
 	u8	sbal_number;
 	u8	sbal_first;
 	u8	sbal_last;
@@ -108,4 +116,98 @@ zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
 			       q_req->sbale_curr);
 }
 
+/**
+ * zfcp_qdio_req_init - initialize qdio request
+ * @qdio: request queue where to start putting the request
+ * @q_req: the qdio request to start
+ * @req_id: The request id
+ * @sbtype: type flags to set for all sbals
+ * @data: First data block
+ * @len: Length of first data block
+ *
+ * This is the start of putting the request into the queue, the last
+ * step is passing the request to zfcp_qdio_send. The request queue
+ * lock must be held during the whole process from init to send.
+ */
+static inline
+void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
+			unsigned long req_id, u32 sbtype, void *data, u32 len)
+{
+	struct qdio_buffer_element *sbale;
+
+	q_req->sbal_first = q_req->sbal_last = qdio->req_q.first;
+	q_req->sbal_number = 1;
+	q_req->sbtype = sbtype;
+
+	sbale = zfcp_qdio_sbale_req(qdio, q_req);
+	sbale->addr = (void *) req_id;
+	sbale->flags |= SBAL_FLAGS0_COMMAND;
+	sbale->flags |= sbtype;
+
+	q_req->sbale_curr = 1;
+	sbale++;
+	sbale->addr = data;
+	if (likely(data))
+		sbale->length = len;
+}
+
+/**
+ * zfcp_qdio_fill_next - Fill next sbale, only for single sbal requests
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_queue_req
+ *
+ * This is only required for single sbal requests, calling it when
+ * wrapping around to the next sbal is a bug.
+ */
+static inline
+void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
+			 void *data, u32 len)
+{
+	struct qdio_buffer_element *sbale;
+
+	BUG_ON(q_req->sbale_curr == ZFCP_QDIO_LAST_SBALE_PER_SBAL);
+	q_req->sbale_curr++;
+	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
+	sbale->addr = data;
+	sbale->length = len;
+}
+
+/**
+ * zfcp_qdio_set_sbale_last - set last entry flag in current sbale
+ * @qdio: pointer to struct zfcp_qdio
+ * @q_req: pointer to struct zfcp_queue_req
+ */
+static inline
+void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
+			      struct zfcp_qdio_req *q_req)
+{
+	struct qdio_buffer_element *sbale;
+
+	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
+	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
+}
+
+/**
+ * zfcp_qdio_sg_one_sbal - check if one sbale is enough for sg data
+ * @sg: The scatterlist where to check the data size
+ *
+ * Returns: 1 when one sbale is enough for the data in the scatterlist,
+ *	    0 if not.
+ */
+static inline
+int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
+{
+	return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
+}
+
+/**
+ * zfcp_qdio_skip_to_last_sbale - skip to last sbale in sbal
+ * @q_req: The current zfcp_qdio_req
+ */
+static inline
+void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio_req *q_req)
+{
+	q_req->sbale_curr = ZFCP_QDIO_LAST_SBALE_PER_SBAL;
+}
+
 #endif /* ZFCP_QDIO_H */

drivers/s390/scsi/zfcp_scsi.c

@@ -677,11 +677,11 @@ struct zfcp_data zfcp_data = {
 		.eh_host_reset_handler	 = zfcp_scsi_eh_host_reset_handler,
 		.can_queue		 = 4096,
 		.this_id		 = -1,
-		.sg_tablesize		 = ZFCP_MAX_SBALES_PER_REQ,
+		.sg_tablesize		 = ZFCP_FSF_MAX_SBALES_PER_REQ,
 		.cmd_per_lun		 = 1,
 		.use_clustering		 = 1,
 		.sdev_attrs		 = zfcp_sysfs_sdev_attrs,
-		.max_sectors		 = (ZFCP_MAX_SBALES_PER_REQ * 8),
+		.max_sectors		 = (ZFCP_FSF_MAX_SBALES_PER_REQ * 8),
 		.dma_boundary		 = ZFCP_QDIO_SBALE_LEN - 1,
 		.shost_attrs		 = zfcp_sysfs_shost_attrs,
 	},