IB/hfi1: Implement CCA for TID RDMA protocol

Currently, FECN handling is not implemented on TID RDMA expected receive
packets and therefore CCA can't be turned on when TID RDMA is
enabled. This patch adds the CCA support to TID RDMA protocol by:

- modifying FECN RSM rule to include kernel receive contexts

- For TID_RDMA READ RESP or TID RDMA ACK packet, a CNP will be sent out if
  the FECN bit is set. For other TID RDMA packets that generate at least
  one response packet, the BECN bit will be set in the first response
  packet

- Copying expected packet data to destination buffer when FECN bit is set
  in the TID RDMA READ RESP or TID RDMA WRITE DATA packet. In this case,
  the expected packet is received as an eager packet

- Handling the TID sequence error for subsequent normal expected packets.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 22 insertions, 13 deletions

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index 9784c6c0d2ec..16861d9ba1b7 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -13297,15 +13297,18 @@ static int set_up_context_variables(struct hfi1_devdata *dd)
 	/*
 	 * The RMT entries are currently allocated as shown below:
 	 * 1. QOS (0 to 128 entries);
-	 * 2. FECN for PSM (num_user_contexts + num_vnic_contexts);
+	 * 2. FECN (num_kernel_context - 1 + num_user_contexts +
+	 *    num_vnic_contexts);
 	 * 3. VNIC (num_vnic_contexts).
-	 * It should be noted that PSM FECN oversubscribe num_vnic_contexts
+	 * It should be noted that FECN oversubscribe num_vnic_contexts
 	 * entries of RMT because both VNIC and PSM could allocate any receive
 	 * context between dd->first_dyn_alloc_text and dd->num_rcv_contexts,
 	 * and PSM FECN must reserve an RMT entry for each possible PSM receive
 	 * context.
 	 */
 	rmt_count = qos_rmt_entries(dd, NULL, NULL) + (num_vnic_contexts * 2);
+	if (HFI1_CAP_IS_KSET(TID_RDMA))
+		rmt_count += num_kernel_contexts - 1;
 	if (rmt_count + n_usr_ctxts > NUM_MAP_ENTRIES) {
 		user_rmt_reduced = NUM_MAP_ENTRIES - rmt_count;
 		dd_dev_err(dd,
@@ -14288,37 +14291,43 @@ bail:
 	init_qpmap_table(dd, FIRST_KERNEL_KCTXT, dd->n_krcv_queues - 1);
 }
 
-static void init_user_fecn_handling(struct hfi1_devdata *dd,
-				    struct rsm_map_table *rmt)
+static void init_fecn_handling(struct hfi1_devdata *dd,
+			       struct rsm_map_table *rmt)
 {
 	struct rsm_rule_data rrd;
 	u64 reg;
-	int i, idx, regoff, regidx;
+	int i, idx, regoff, regidx, start;
 	u8 offset;
 	u32 total_cnt;
 
+	if (HFI1_CAP_IS_KSET(TID_RDMA))
+		/* Exclude context 0 */
+		start = 1;
+	else
+		start = dd->first_dyn_alloc_ctxt;
+
+	total_cnt = dd->num_rcv_contexts - start;
+
 	/* there needs to be enough room in the map table */
-	total_cnt = dd->num_rcv_contexts - dd->first_dyn_alloc_ctxt;
 	if (rmt->used + total_cnt >= NUM_MAP_ENTRIES) {
-		dd_dev_err(dd, "User FECN handling disabled - too many user contexts allocated\n");
+		dd_dev_err(dd, "FECN handling disabled - too many contexts allocated\n");
 		return;
 	}
 
 	/*
 	 * RSM will extract the destination context as an index into the
 	 * map table.  The destination contexts are a sequential block
-	 * in the range first_dyn_alloc_ctxt...num_rcv_contexts-1 (inclusive).
+	 * in the range start...num_rcv_contexts-1 (inclusive).
 	 * Map entries are accessed as offset + extracted value.  Adjust
 	 * the added offset so this sequence can be placed anywhere in
 	 * the table - as long as the entries themselves do not wrap.
 	 * There are only enough bits in offset for the table size, so
 	 * start with that to allow for a "negative" offset.
 	 */
-	offset = (u8)(NUM_MAP_ENTRIES + (int)rmt->used -
-						(int)dd->first_dyn_alloc_ctxt);
+	offset = (u8)(NUM_MAP_ENTRIES + rmt->used - start);
 
-	for (i = dd->first_dyn_alloc_ctxt, idx = rmt->used;
-				i < dd->num_rcv_contexts; i++, idx++) {
+	for (i = start, idx = rmt->used; i < dd->num_rcv_contexts;
+	     i++, idx++) {
 		/* replace with identity mapping */
 		regoff = (idx % 8) * 8;
 		regidx = idx / 8;
@@ -14440,7 +14449,7 @@ static void init_rxe(struct hfi1_devdata *dd)
 	rmt = alloc_rsm_map_table(dd);
 	/* set up QOS, including the QPN map table */
 	init_qos(dd, rmt);
-	init_user_fecn_handling(dd, rmt);
+	init_fecn_handling(dd, rmt);
 	complete_rsm_map_table(dd, rmt);
 	/* record number of used rsm map entries for vnic */
 	dd->vnic.rmt_start = rmt->used;