[openib-general] [PATCH RFC 4 of 5] IB/mthca: QoS support

[Michael S. Tsirkin]

encode SL in sched_queue field to improve hardware QoS guarantees
for connected QPs.

Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>

---

Index: linux-2.6/drivers/infiniband/hw/mthca/mthca_qp.c
===================================================================
--- linux-2.6.orig/drivers/infiniband/hw/mthca/mthca_qp.c
+++ linux-2.6/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -49,6 +49,10 @@
 #include "mthca_memfree.h"
 #include "mthca_wqe.h"
 
+static int mthca_qos_support = 0;
+module_param_named(qos_support, mthca_qos_support, int, 0644);
+MODULE_PARM_DESC(qos_support, "Enable QoS support if > 0");
+
 enum {
 	MTHCA_MAX_DIRECT_QP_SIZE = 4 * PAGE_SIZE,
 	MTHCA_ACK_REQ_FREQ       = 10,
@@ -694,6 +698,19 @@ int mthca_modify_qp(struct ib_qp *ibqp, 
 			goto out_mailbox;
 
 		qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_PRIMARY_ADDR_PATH);
+		if (mthca_qos_support) {
+			u8 sl = attr->ah_attr.sl;
+			u8 sched_queue = (sl & 0x8) | (sl & (~(sl >> 1)) & 0x4) |
+				((sl >> 1) & (sl >> 2) & 0x2) | ((sl >> 1) & 0x1);
+
+			if (mthca_is_memfree(dev)) {
+				qp_context->rlkey_arbel_sched_queue |= sched_queue;
+			} else {
+				qp_context->tavor_sched_queue |= sched_queue;
+			}
+			qp_param->opt_param_mask |=
+				cpu_to_be32(MTHCA_QP_OPTPAR_SCHED_QUEUE);
+		}
 	}
 
 	if (attr_mask & IB_QP_TIMEOUT) {


-- 
MST