IB: Add CQ comp_vector support

Add a num_comp_vectors member to struct ib_device and extend
ib_create_cq() to pass in a comp_vector parameter -- this parallels
the userspace libibverbs API.  Update all hardware drivers to set
num_comp_vectors to 1 and have all ULPs pass 0 for the comp_vector
value.  Pass the value of num_comp_vectors to userspace rather than
hard-coding a value of 1.

We want multiple CQ event vector support (via MSI-X or similar for
adapters that can generate multiple interrupts), but it's not clear
how many vectors we want, or how we want to deal with policy issues
such as how to decide which vector to use or how to set up interrupt
affinity.  This patch is useful for experimenting, since no core
changes will be necessary when updating a driver to support multiple
vectors, and we know that we want to make at least these changes
anyway.

Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 765589f4d166..17cc309d03ef 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -912,6 +912,8 @@ struct ib_device {
 
         u32                           flags;
 
+        int                           num_comp_vectors;
+
         struct iw_cm_verbs           *iwcm;
 
         int                        (*query_device)(struct ib_device *device,
@@ -978,6 +980,7 @@ struct ib_device {
                                                 struct ib_recv_wr *recv_wr,
                                                 struct ib_recv_wr **bad_recv_wr);
         struct ib_cq *             (*create_cq)(struct ib_device *device, int cqe,
+                                                int comp_vector,
                                                 struct ib_ucontext *context,
                                                 struct ib_udata *udata);
         int                        (*destroy_cq)(struct ib_cq *cq);
@@ -1358,13 +1361,15 @@ static inline int ib_post_recv(struct ib_qp *qp,
  * @cq_context: Context associated with the CQ returned to the user via
  *   the associated completion and event handlers.
  * @cqe: The minimum size of the CQ.
+ * @comp_vector - Completion vector used to signal completion events.
+ *     Must be >= 0 and < context->num_comp_vectors.
  *
  * Users can examine the cq structure to determine the actual CQ size.
  */
 struct ib_cq *ib_create_cq(struct ib_device *device,
                            ib_comp_handler comp_handler,
                            void (*event_handler)(struct ib_event *, void *),
-                           void *cq_context, int cqe);
+                           void *cq_context, int cqe, int comp_vector);
 
 /**
  * ib_resize_cq - Modifies the capacity of the CQ.