[openib-general] Re: ib_mad.h ib_mad_recv_wc.mad_flags

[Sean Hefty]

On Tue, 7 Sep 2004 14:12:27 -0700
Sean Hefty <mshefty at ichips.intel.com> wrote:

> I will see if there's a way to have the MAD receive completion match closer with the normal receive completion case.  For example, ib_wc is the only structure that uses bit fields for flags.  Other structures in the API use an integer set using enum values.

Here's a patch for discussion that changes ib_mad_recv_wc to use ib_wc.  The intent of the patch is to allow an API that: supports 0-copy receives, is efficient for processing non-RMPP receives, and helps simplify the underlying MAD implementation.

Along these same lines, I thought about removing ib_mad_send_wc, and using ib_wc directly.  I held off on this change for now.  I also thought about replacing the bit fields in ib_wc with a single flag field.  If I do that I'll submit a patch for Roland's stack, since it changes the verbs API.

Comments?

- Sean

Index: ib_mad.h
===================================================================
--- ib_mad.h	(revision 750)
+++ ib_mad.h	(working copy)
@@ -130,10 +130,6 @@
 	u32			hi_tid;
 };
 
-enum ib_mad_flags {
-	IB_MAD_GRH_VALID	= 1
-};
-
 /**
  * ib_mad_send_wc - MAD send completion information.
  * @wr_id - Work request identifier associated with the send MAD request.
@@ -148,36 +144,32 @@
 };
 
 /**
- * ib_mad_recv_wc - received MAD information.
- * @wr_id - For received response, set to the work request identifier specified
- *   for the corresponding send request.
+ * ib_mad_recv_buf - received MAD buffer information.
+ * @list - Reference to next data buffer for a received RMPP MAD.
  * @grh - References a data buffer containing the global route header.
  *   The data refereced by this buffer is only valid if the GRH is
  *   valid.
  * @mad - References the start of the received MAD.
- * @length - Specifies the size of the received MAD.
- * @mad_flags - Flags used to specify information about the received MAD.
+ */
+struct ib_mad_recv_buf {
+	struct list_head	list;
+	struct ib_grh		*grh;
+	struct ib_mad		*mad;
+};
+
+/**
+ * ib_mad_recv_wc - received MAD information.
+ * @wc - Completion information for the received data.
+ * @recv_buf - Specifies the location of the received data buffer(s).
  * @mad_len - The length of the received MAD, without duplicated headers.
- * @src_qpn - Source QP.
- * @pkey_index - Pkey index.
- * @slid - LID of remote QP.
- * @sl - Service level of source for a received message.
- * @dlid_path_bits - Path bits of source for a received message.
  *
- * An RMPP receive will be coalesced into a single data buffer.
+ * For received response, the wr_id field of the wc is set to the wr_id
+ *   for the corresponding send request.
  */
 struct ib_mad_recv_wc {
-	u64			wr_id;
-	struct ib_grh		*grh;
-	struct ib_mad		*mad;
-	u32			length;
-	int			mad_flags;
-	u32			mad_len;
-	u32			src_qp;
-	u16			pkey_index;
-	u16			slid;
-	u8			sl;
-	u8			dlid_path_bits;
+	struct ib_wc		*wc;
+	struct ib_mad_recv_buf	*recv_buf;
+	int			mad_len;
 };
 
 /**