[PATCH for-next v2 3/5] RDMA/rxe: Create AH index and return to user space

[Bob Pearson <rpearsonhpe@gmail.com>]

Modify rxe_create_ah() to add an index to AH when created and if
called from a new user provider return it to user space. If called
from an old provider mark the AH as not having a useful index.
Modify rxe_destroy_ah to drop the index before deleting the object.

Also use the PD in the core ib_ah struct instead of a duplicate copy in
rxe_ah.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_verbs.c | 31 ++++++++++++++++++++++++++-
 drivers/infiniband/sw/rxe/rxe_verbs.h |  8 ++++++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c
index 4176fffa7fdc..1cc12c913e39 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -161,9 +161,19 @@ static int rxe_create_ah(struct ib_ah *ibah,
 			 struct ib_udata *udata)
 
 {
-	int err;
 	struct rxe_dev *rxe = to_rdev(ibah->device);
 	struct rxe_ah *ah = to_rah(ibah);
+	struct rxe_create_ah_resp __user *uresp = NULL;
+	int err;
+
+	if (udata) {
+		/* test if new user provider */
+		if (udata->outlen >= sizeof(*uresp))
+			uresp = udata->outbuf;
+		ah->is_user = true;
+	} else {
+		ah->is_user = false;
+	}
 
 	err = rxe_av_chk_attr(rxe, init_attr->ah_attr);
 	if (err)
@@ -173,6 +183,24 @@ static int rxe_create_ah(struct ib_ah *ibah,
 	if (err)
 		return err;
 
+	/* create index > 0 */
+	rxe_add_index(ah);
+	ah->ah_num = ah->pelem.index;
+
+	if (uresp) {
+		/* only if new user provider */
+		err = copy_to_user(&uresp->ah_num, &ah->ah_num,
+					 sizeof(uresp->ah_num));
+		if (err) {
+			rxe_drop_index(ah);
+			rxe_drop_ref(ah);
+			return -EFAULT;
+		}
+	} else if (ah->is_user) {
+		/* only if old user provider */
+		ah->ah_num = 0;
+	}
+
 	rxe_init_av(init_attr->ah_attr, &ah->av);
 	return 0;
 }
@@ -205,6 +233,7 @@ static int rxe_destroy_ah(struct ib_ah *ibah, u32 flags)
 {
 	struct rxe_ah *ah = to_rah(ibah);
 
+	rxe_drop_index(ah);
 	rxe_drop_ref(ah);
 	return 0;
 }
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index 959a3260fcab..fa234d7ad382 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -46,8 +46,9 @@ struct rxe_pd {
 struct rxe_ah {
 	struct ib_ah		ibah;
 	struct rxe_pool_entry	pelem;
-	struct rxe_pd		*pd;
 	struct rxe_av		av;
+	bool			is_user;
+	int			ah_num;
 };
 
 struct rxe_cqe {
@@ -469,6 +470,11 @@ static inline struct rxe_mw *to_rmw(struct ib_mw *mw)
 	return mw ? container_of(mw, struct rxe_mw, ibmw) : NULL;
 }
 
+static inline struct rxe_pd *ah_pd(struct rxe_ah *ah)
+{
+	return to_rpd(ah->ibah.pd);
+}
+
 static inline struct rxe_pd *mr_pd(struct rxe_mr *mr)
 {
 	return to_rpd(mr->ibmr.pd);
-- 
2.30.2