[SCSI] libiscsi: prepare libiscsi for new offload engines by modifying unsol data code

cxgb3i offloads data transfers. It does not offload the entire scsi/iscsi
procssing like qla4xxx and it does not offload the iscsi sequence
processing like how bnx2i does. cxgb3i relies on iscsi_tcp for the
seqeunce handling so this changes how we transfer unsolicitied data by
adding a common r2t struct and helpers.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 34 insertions, 9 deletions

diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 61e53f14f7e1..51500573c0b8 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -93,24 +93,38 @@ enum {
         ISCSI_TASK_RUNNING,
 };
 
+struct iscsi_r2t_info {
+        __be32                  ttt;            /* copied from R2T */
+        __be32                  exp_statsn;     /* copied from R2T */
+        uint32_t                data_length;    /* copied from R2T */
+        uint32_t                data_offset;    /* copied from R2T */
+        int                     data_count;     /* DATA-Out payload progress */
+        int                     datasn;
+        /* LLDs should set/update these values */
+        int                     sent;           /* R2T sequence progress */
+};
+
 struct iscsi_task {
         /*
          * Because LLDs allocate their hdr differently, this is a pointer
          * and length to that storage. It must be setup at session
          * creation time.
          */
-        struct iscsi_cmd        *hdr;
+        struct iscsi_hdr        *hdr;
         unsigned short          hdr_max;
         unsigned short          hdr_len;        /* accumulated size of hdr used */
+        /* copied values in case we need to send tmfs */
+        itt_t                   hdr_itt;
+        __be32                  cmdsn;
+        uint8_t                 lun[8];
+
         int                     itt;            /* this ITT */
 
-        uint32_t                unsol_datasn;
         unsigned                imm_count;      /* imm-data (bytes)   */
-        unsigned                unsol_count;    /* unsolicited (bytes)*/
         /* offset in unsolicited stream (bytes); */
-        unsigned                unsol_offset;
-        unsigned                data_count;     /* remaining Data-Out */
+        struct iscsi_r2t_info   unsol_r2t;
         char                    *data;          /* mgmt payload */
+        unsigned                data_count;
         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
         struct iscsi_conn       *conn;          /* used connection    */
 
@@ -121,6 +135,11 @@ struct iscsi_task {
         void                    *dd_data;       /* driver/transport data */
 };
 
+static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
+{
+        return task->unsol_r2t.data_length > task->unsol_r2t.sent;
+}
+
 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 {
         return (void*)task->hdr + task->hdr_len;
@@ -376,8 +395,9 @@ extern void iscsi_suspend_tx(struct iscsi_conn *conn);
  * pdu and task processing
  */
 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
-extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
-                                        struct iscsi_data *hdr);
+extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
+                                    struct iscsi_r2t_info *r2t,
+                                    struct iscsi_data *hdr);
 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
                                 char *, uint32_t);
 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index c667cc396545..c928234c018f 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -113,10 +113,15 @@ struct iscsi_transport {
                          char *data, uint32_t data_size);
         void (*get_stats) (struct iscsi_cls_conn *conn,
                            struct iscsi_stats *stats);
+
         int (*init_task) (struct iscsi_task *task);
         int (*xmit_task) (struct iscsi_task *task);
-        void (*cleanup_task) (struct iscsi_conn *conn,
-                                  struct iscsi_task *task);
+        void (*cleanup_task) (struct iscsi_task *task);
+
+        int (*alloc_pdu) (struct iscsi_task *task);
+        int (*xmit_pdu) (struct iscsi_task *task);
+        int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
+                         unsigned int count);
         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
         struct iscsi_endpoint *(*ep_connect) (struct sockaddr *dst_addr,
                                               int non_blocking);