IB/uverbs: Add CQ moderation capability to query_device

The query_device function can now obtain the maximum values for
cq_max_count and cq_period, needed for CQ moderation.
cq_max_count is a 16 bits number that determines the number
of CQEs to accumulate before generating an event.
cq_period is a 16 bits number that determines the timeout in micro
seconds from the last event generated, upon which a new event will
be generated even if cq_max_count was not reached.

Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>

3 files changed, 22 insertions, 0 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 3c2673cd4090..53143e4b1c50 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -3852,6 +3852,15 @@ int ib_uverbs_ex_query_device(struct ib_uverbs_file *file,
         resp.tm_caps.max_sge            = attr.tm_caps.max_sge;
         resp.tm_caps.flags              = attr.tm_caps.flags;
         resp.response_length += sizeof(resp.tm_caps);
+
+        if (ucore->outlen < resp.response_length + sizeof(resp.cq_moderation_caps))
+                goto end;
+
+        resp.cq_moderation_caps.max_cq_moderation_count  =
+                attr.cq_caps.max_cq_moderation_count;
+        resp.cq_moderation_caps.max_cq_moderation_period =
+                attr.cq_caps.max_cq_moderation_period;
+        resp.response_length += sizeof(resp.cq_moderation_caps);
 end:
         err = ib_copy_to_udata(ucore, &resp, resp.response_length);
         return err;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 8e0d3780ce4e..0b484c023fa9 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -315,6 +315,11 @@ enum ib_cq_attr_mask {
         IB_CQ_MODERATE = 1 << 0,
 };
 
+struct ib_cq_caps {
+        u16     max_cq_moderation_count;
+        u16     max_cq_moderation_period;
+};
+
 struct ib_device_attr {
         u64                     fw_ver;
         __be64                  sys_image_guid;
@@ -365,6 +370,7 @@ struct ib_device_attr {
         u32                     max_wq_type_rq;
         u32                     raw_packet_caps; /* Use ib_raw_packet_caps enum */
         struct ib_tm_caps       tm_caps;
+        struct ib_cq_caps       cq_caps;
 };
 
 enum ib_mtu {
diff --git a/include/uapi/rdma/ib_user_verbs.h b/include/uapi/rdma/ib_user_verbs.h
index cfa09d6095d6..5186fb12629b 100644
--- a/include/uapi/rdma/ib_user_verbs.h
+++ b/include/uapi/rdma/ib_user_verbs.h
@@ -125,6 +125,12 @@ struct ib_uverbs_comp_event_desc {
         __u64 cq_handle;
 };
 
+struct ib_uverbs_cq_moderation_caps {
+        __u16     max_cq_moderation_count;
+        __u16     max_cq_moderation_period;
+        __u32     reserved;
+};
+
 /*
  * All commands from userspace should start with a __u32 command field
  * followed by __u16 in_words and out_words fields (which give the
@@ -263,6 +269,7 @@ struct ib_uverbs_ex_query_device_resp {
         __u32  max_wq_type_rq;
         __u32 raw_packet_caps;
         struct ib_uverbs_tm_caps tm_caps;
+        struct ib_uverbs_cq_moderation_caps cq_moderation_caps;
 };
 
 struct ib_uverbs_query_port {