[PATCH V3 1/4] RDMA/core: Add protection for shared CQs used by ULPs

[Yamin Friedman <yaminf@xxxxxxxxxxxx>]

A pre-step for adding shared CQs. Add the infrastructure to prevent
shared CQ users from altering the CQ configurations. For now all cqs are
marked as private (non-shared). The core driver should use the new force
functions to perform resize/destroy/moderation changes that are not
allowed for users of shared CQs.

Signed-off-by: Yamin Friedman <yaminf@xxxxxxxxxxxx>
Reviewed-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Reviewed-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
 drivers/infiniband/core/verbs.c | 9 +++++++++
 include/rdma/ib_verbs.h         | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index bf0249f..675f601 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -1990,6 +1990,9 @@ struct ib_cq *__ib_create_cq(struct ib_device *device,
 
 int rdma_set_cq_moderation(struct ib_cq *cq, u16 cq_count, u16 cq_period)
 {
+	if (cq->shared)
+		return -EOPNOTSUPP;
+
 	return cq->device->ops.modify_cq ?
 		cq->device->ops.modify_cq(cq, cq_count,
 					  cq_period) : -EOPNOTSUPP;
@@ -1998,6 +2001,9 @@ int rdma_set_cq_moderation(struct ib_cq *cq, u16 cq_count, u16 cq_period)
 
 int ib_destroy_cq_user(struct ib_cq *cq, struct ib_udata *udata)
 {
+	if (WARN_ON_ONCE(cq->shared))
+		return -EOPNOTSUPP;
+
 	if (atomic_read(&cq->usecnt))
 		return -EBUSY;
 
@@ -2010,6 +2016,9 @@ int ib_destroy_cq_user(struct ib_cq *cq, struct ib_udata *udata)
 
 int ib_resize_cq(struct ib_cq *cq, int cqe)
 {
+	if (cq->shared)
+		return -EOPNOTSUPP;
+
 	return cq->device->ops.resize_cq ?
 		cq->device->ops.resize_cq(cq, cqe, NULL) : -EOPNOTSUPP;
 }
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 4c488ca..1659131 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1582,6 +1582,7 @@ struct ib_cq {
 	 * Implementation details of the RDMA core, don't use in drivers:
 	 */
 	struct rdma_restrack_entry res;
+	u8 shared:1;
 };
 
 struct ib_srq {
@@ -3824,6 +3825,8 @@ static inline struct ib_cq *ib_alloc_cq_any(struct ib_device *dev,
  * ib_free_cq_user - Free kernel/user CQ
  * @cq: The CQ to free
  * @udata: Valid user data or NULL for kernel objects
+ *
+ * NOTE: This function shouldn't be called on shared CQs.
  */
 void ib_free_cq_user(struct ib_cq *cq, struct ib_udata *udata);
 
-- 
1.8.3.1