IB/umad: Add support for large RMPP transfers

Add support for sending and receiving large RMPP transfers.  The old
code supports transfers only as large as a single contiguous kernel
memory allocation.  This patch uses linked list of memory buffers when
sending and receiving data to avoid needing contiguous pages for
larger transfers.

  Receive side: copy the arriving MADs in chunks instead of coalescing
  to one large buffer in kernel space.

  Send side: split a multipacket MAD buffer to a list of segments,
  (multipacket_list) and send these using a gather list of size 2.
  Also, save pointer to last sent segment, and retrieve requested
  segments by walking list starting at last sent segment. Finally,
  save pointer to last-acked segment.  When retrying, retrieve
  segments for resending relative to this pointer.  When updating last
  ack, start at this pointer.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/infiniband/core/mad_priv.h b/drivers/infiniband/core/mad_priv.h
index 570f78682af3..a7125d4b5ccf 100644
--- a/drivers/infiniband/core/mad_priv.h
+++ b/drivers/infiniband/core/mad_priv.h
@@ -31,7 +31,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
- * $Id: mad_priv.h 2730 2005-06-28 16:43:03Z sean.hefty $
+ * $Id: mad_priv.h 5596 2006-03-03 01:00:07Z sean.hefty $
  */
 
 #ifndef __IB_MAD_PRIV_H__
@@ -85,6 +85,12 @@ struct ib_mad_private {
 	} mad;
 } __attribute__ ((packed));
 
+struct ib_rmpp_segment {
+	struct list_head list;
+	u32 num;
+	u8 data[0];
+};
+
 struct ib_mad_agent_private {
 	struct list_head agent_list;
 	struct ib_mad_agent agent;
@@ -119,7 +125,8 @@ struct ib_mad_send_wr_private {
 	struct list_head agent_list;
 	struct ib_mad_agent_private *mad_agent_priv;
 	struct ib_mad_send_buf send_buf;
-	DECLARE_PCI_UNMAP_ADDR(mapping)
+	DECLARE_PCI_UNMAP_ADDR(header_mapping)
+	DECLARE_PCI_UNMAP_ADDR(payload_mapping)
 	struct ib_send_wr send_wr;
 	struct ib_sge sg_list[IB_MAD_SEND_REQ_MAX_SG];
 	__be64 tid;
@@ -130,11 +137,12 @@ struct ib_mad_send_wr_private {
 	enum ib_wc_status status;
 
 	/* RMPP control */
+	struct list_head rmpp_list;
+	struct ib_rmpp_segment *last_ack_seg;
+	struct ib_rmpp_segment *cur_seg;
 	int last_ack;
 	int seg_num;
 	int newwin;
-	int total_seg;
-	int data_offset;
 	int pad;
 };