IB/isert: Support the remote invalidation exception

We'll use remote invalidate, according to negotiation result
during connection establishment. If the initiator declared that
it supports the remote invalidate exception and the local HCA
supports IB_DEVICE_MEM_MGT_EXTENSIONS then the target will
use IB_WR_SEND_WITH_INV with the correct rkey for the response.

Signed-off-by: Jenny Derzhavetz <jennyf@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 39 insertions, 7 deletions

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 824a7ad8667b..abb3124f89bb 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -653,6 +653,32 @@ out_login_buf:
 	return ret;
 }
 
+static void
+isert_set_nego_params(struct isert_conn *isert_conn,
+		      struct rdma_conn_param *param)
+{
+	struct ib_device_attr *attr = &isert_conn->device->ib_device->attrs;
+
+	/* Set max inflight RDMA READ requests */
+	isert_conn->initiator_depth = min_t(u8, param->initiator_depth,
+				attr->max_qp_init_rd_atom);
+	isert_dbg("Using initiator_depth: %u\n", isert_conn->initiator_depth);
+
+	if (param->private_data) {
+		u8 flags = *(u8 *)param->private_data;
+
+		/*
+		 * use remote invalidation if the both initiator
+		 * and the HCA support it
+		 */
+		isert_conn->snd_w_inv = !(flags & ISER_SEND_W_INV_NOT_SUP) &&
+					  (attr->device_cap_flags &
+					   IB_DEVICE_MEM_MGT_EXTENSIONS);
+		if (isert_conn->snd_w_inv)
+			isert_info("Using remote invalidation\n");
+	}
+}
+
 static int
 isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 {
@@ -691,11 +717,7 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 	}
 	isert_conn->device = device;
 
-	/* Set max inflight RDMA READ requests */
-	isert_conn->initiator_depth = min_t(u8,
-				event->param.conn.initiator_depth,
-				device->ib_device->attrs.max_qp_init_rd_atom);
-	isert_dbg("Using initiator_depth: %u\n", isert_conn->initiator_depth);
+	isert_set_nego_params(isert_conn, &event->param.conn);
 
 	ret = isert_conn_setup_qp(isert_conn, cma_id);
 	if (ret)
@@ -1074,7 +1096,14 @@ isert_init_send_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
 
 	isert_cmd->rdma_wr.iser_ib_op = ISER_IB_SEND;
 	send_wr->wr_id = (uintptr_t)&isert_cmd->tx_desc;
-	send_wr->opcode = IB_WR_SEND;
+
+	if (isert_conn->snd_w_inv && isert_cmd->inv_rkey) {
+		send_wr->opcode  = IB_WR_SEND_WITH_INV;
+		send_wr->ex.invalidate_rkey = isert_cmd->inv_rkey;
+	} else {
+		send_wr->opcode = IB_WR_SEND;
+	}
+
 	send_wr->sg_list = &tx_desc->tx_sg[0];
 	send_wr->num_sge = isert_cmd->tx_desc.num_sge;
 	send_wr->send_flags = IB_SEND_SIGNALED;
@@ -1463,6 +1492,7 @@ isert_rx_opcode(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc,
 		isert_cmd->read_va = read_va;
 		isert_cmd->write_stag = write_stag;
 		isert_cmd->write_va = write_va;
+		isert_cmd->inv_rkey = read_stag ? read_stag : write_stag;
 
 		ret = isert_handle_scsi_cmd(isert_conn, isert_cmd, cmd,
 					rx_desc, (unsigned char *)hdr);
@@ -3080,7 +3110,9 @@ isert_rdma_accept(struct isert_conn *isert_conn)
 	cp.rnr_retry_count = 7;
 
 	memset(&rsp_hdr, 0, sizeof(rsp_hdr));
-	rsp_hdr.flags = (ISERT_ZBVA_NOT_USED | ISERT_SEND_W_INV_NOT_USED);
+	rsp_hdr.flags = ISERT_ZBVA_NOT_USED;
+	if (!isert_conn->snd_w_inv)
+		rsp_hdr.flags = rsp_hdr.flags | ISERT_SEND_W_INV_NOT_USED;
 	cp.private_data = (void *)&rsp_hdr;
 	cp.private_data_len = sizeof(rsp_hdr);