RDMA/hns: Append SCC context to the raw dump of QPC

SCCC (SCC Context) is a context with QP granularity that contains
information about congestion control. Dump SCCC and QPC together
to improve troubleshooting.

When dumping raw QPC with rdmatool, there will be a total of 576 bytes
data output, where the first 512 bytes is QPC and the last 64 bytes is
SCCC. When congestion control is disabled, the 64 byte SCCC will be all 0.

Example:
$rdma res show qp -jpr
[ {
        "ifindex": 0,
        "ifname": "hns_0",
	"data": [ 67,0,0,0... 512bytes
		  4,0,2... 64bytes]
  },...
} ]

Signed-off-by: wenglianfa <[email protected]>
Signed-off-by: Junxian Huang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Leon Romanovsky <[email protected]>

Author: wenglianfa

drivers/infiniband/hw/hns/hns_roce_cmd.h

@@ -108,6 +108,9 @@ enum {
 	HNS_ROCE_CMD_QUERY_CEQC		= 0x92,
 	HNS_ROCE_CMD_DESTROY_CEQC	= 0x93,
 
+	/* SCC CTX commands */
+	HNS_ROCE_CMD_QUERY_SCCC		= 0xa2,
+
 	/* SCC CTX BT commands */
 	HNS_ROCE_CMD_READ_SCCC_BT0	= 0xa4,
 	HNS_ROCE_CMD_WRITE_SCCC_BT0	= 0xa5,

drivers/infiniband/hw/hns/hns_roce_device.h

@@ -947,6 +947,7 @@ struct hns_roce_hw {
 	int (*query_qpc)(struct hns_roce_dev *hr_dev, u32 qpn, void *buffer);
 	int (*query_mpt)(struct hns_roce_dev *hr_dev, u32 key, void *buffer);
 	int (*query_srqc)(struct hns_roce_dev *hr_dev, u32 srqn, void *buffer);
+	int (*query_sccc)(struct hns_roce_dev *hr_dev, u32 qpn, void *buffer);
 	int (*query_hw_counter)(struct hns_roce_dev *hr_dev,
 				u64 *stats, u32 port, int *hw_counters);
 	const struct ib_device_ops *hns_roce_dev_ops;

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -5317,6 +5317,30 @@ static int hns_roce_v2_query_srqc(struct hns_roce_dev *hr_dev, u32 srqn,
 	return ret;
 }
 
+static int hns_roce_v2_query_sccc(struct hns_roce_dev *hr_dev, u32 qpn,
+				  void *buffer)
+{
+	struct hns_roce_v2_scc_context *context;
+	struct hns_roce_cmd_mailbox *mailbox;
+	int ret;
+
+	mailbox = hns_roce_alloc_cmd_mailbox(hr_dev);
+	if (IS_ERR(mailbox))
+		return PTR_ERR(mailbox);
+
+	ret = hns_roce_cmd_mbox(hr_dev, 0, mailbox->dma, HNS_ROCE_CMD_QUERY_SCCC,
+				qpn);
+	if (ret)
+		goto out;
+
+	context = mailbox->buf;
+	memcpy(buffer, context, sizeof(*context));
+
+out:
+	hns_roce_free_cmd_mailbox(hr_dev, mailbox);
+	return ret;
+}
+
 static u8 get_qp_timeout_attr(struct hns_roce_dev *hr_dev,
 			      struct hns_roce_v2_qp_context *context)
 {
@@ -6709,6 +6733,7 @@ static const struct hns_roce_hw hns_roce_hw_v2 = {
 	.query_qpc = hns_roce_v2_query_qpc,
 	.query_mpt = hns_roce_v2_query_mpt,
 	.query_srqc = hns_roce_v2_query_srqc,
+	.query_sccc = hns_roce_v2_query_sccc,
 	.query_hw_counter = hns_roce_hw_v2_query_counter,
 	.hns_roce_dev_ops = &hns_roce_v2_dev_ops,
 	.hns_roce_dev_srq_ops = &hns_roce_v2_dev_srq_ops,

drivers/infiniband/hw/hns/hns_roce_hw_v2.h

@@ -646,6 +646,12 @@ struct hns_roce_v2_qp_context {
 #define QPCEX_SQ_RQ_NOT_FORBID_EN QPCEX_FIELD_LOC(23, 23)
 #define QPCEX_STASH QPCEX_FIELD_LOC(82, 82)
 
+#define SCC_CONTEXT_SIZE 16
+
+struct hns_roce_v2_scc_context {
+	__le32 data[SCC_CONTEXT_SIZE];
+};
+
 #define	V2_QP_RWE_S 1 /* rdma write enable */
 #define	V2_QP_RRE_S 2 /* rdma read enable */
 #define	V2_QP_ATE_S 3 /* rdma atomic enable */

drivers/infiniband/hw/hns/hns_roce_restrack.c

@@ -97,16 +97,33 @@ int hns_roce_fill_res_qp_entry_raw(struct sk_buff *msg, struct ib_qp *ib_qp)
 {
 	struct hns_roce_dev *hr_dev = to_hr_dev(ib_qp->device);
 	struct hns_roce_qp *hr_qp = to_hr_qp(ib_qp);
-	struct hns_roce_v2_qp_context context;
+	struct hns_roce_full_qp_ctx {
+		struct hns_roce_v2_qp_context qpc;
+		struct hns_roce_v2_scc_context sccc;
+	} context = {};
 	int ret;
 
 	if (!hr_dev->hw->query_qpc)
 		return -EINVAL;
 
-	ret = hr_dev->hw->query_qpc(hr_dev, hr_qp->qpn, &context);
+	ret = hr_dev->hw->query_qpc(hr_dev, hr_qp->qpn, &context.qpc);
 	if (ret)
-		return -EINVAL;
+		return ret;
+
+	/* If SCC is disabled or the query fails, the queried SCCC will
+	 * be all 0.
+	 */
+	if (!(hr_dev->caps.flags & HNS_ROCE_CAP_FLAG_QP_FLOW_CTRL) ||
+	    !hr_dev->hw->query_sccc)
+		goto out;
+
+	ret = hr_dev->hw->query_sccc(hr_dev, hr_qp->qpn, &context.sccc);
+	if (ret)
+		ibdev_warn_ratelimited(&hr_dev->ib_dev,
+				       "failed to query SCCC, ret = %d.\n",
+				       ret);
 
+out:
 	ret = nla_put(msg, RDMA_NLDEV_ATTR_RES_RAW, sizeof(context), &context);
 
 	return ret;