[dpdk-dev] [PATCH] ethdev: add support for WRED thresholds in bytes

[Nikhil Rao <nikhil.rao@intel.com>]

WRED thresholds can be specified in bytes if the TM leaf
node supports it. Also extend WRED thresholds to 32 bits from 16.

TM capability (port/level/queue) fields cman_wred_packet_mode_supported and
cman_wred_byte_mode_supported, when non-zero, indicate support for WRED
thresholds in packets and bytes respectively.

The packet_mode member of struct rte_tm_wred_params, when non-zero,
indicates that the min and max thresholds are specified in
packets and when zero, indicates that the min and max thresholds
are specified in bytes.

Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
---

Thanks to Cristian for his help with developing this patch.

 lib/librte_ether/rte_tm.h                | 53 ++++++++++++++++++++++++++++++--
 drivers/net/softnic/rte_eth_softnic_tm.c | 22 +++++++++++++
 2 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/lib/librte_ether/rte_tm.h b/lib/librte_ether/rte_tm.h
index 2b25a87..23098ab 100644
--- a/lib/librte_ether/rte_tm.h
+++ b/lib/librte_ether/rte_tm.h
@@ -377,6 +377,22 @@ struct rte_tm_capabilities {
 	 */
 	uint32_t sched_wfq_weight_max;
 
+	/** WRED packet mode support. When non-zero, this parameter indicates
+	 * that there is atleast one leaf node that supports the WRED packet
+	 * mode, which might not be true for all the leaf nodes. In packet
+	 * mode, the WRED thresholds specify the queue length in packets, as
+	 * opposed to bytes.
+	 */
+	int cman_wred_packet_mode_supported;
+
+	/** WRED byte mode support. When non-zero, this parameter indicates that
+	 * there is atleast one leaf node that supports the WRED byte mode,
+	 * which might not be true for all the leaf nodes. In byte mode, the
+	 * WRED thresholds specify the queue length in bytes, as opposed to
+	 * packets.
+	 */
+	int cman_wred_byte_mode_supported;
+
 	/** Head drop algorithm support. When non-zero, this parameter
 	 * indicates that there is at least one leaf node that supports the head
 	 * drop algorithm, which might not be true for all the leaf nodes.
@@ -628,6 +644,24 @@ struct rte_tm_level_capabilities {
 			 */
 			uint32_t shaper_shared_n_max;
 
+			/** WRED packet mode support. When non-zero, this
+			 * parameter indicates that there is atleast one leaf
+			 * node on this level that supports the WRED packet
+			 * mode, which might not be true for all the leaf
+			 * nodes. In packet mode, the WRED thresholds specify
+			 * the queue length in packets, as opposed to bytes.
+			 */
+			int cman_wred_packet_mode_supported;
+
+			/** WRED byte mode support. When non-zero, this
+			 * parameter indicates that there is atleast one leaf
+			 * node on this level that supports the WRED byte mode,
+			 * which might not be true for all the leaf nodes. In
+			 * byte mode, the WRED thresholds specify the queue
+			 * length in bytes, as opposed to packets.
+			 */
+			int cman_wred_byte_mode_supported;
+
 			/** Head drop algorithm support. When non-zero, this
 			 * parameter indicates that there is at least one leaf
 			 * node on this level that supports the head drop
@@ -743,6 +777,12 @@ struct rte_tm_node_capabilities {
 
 		/** Items valid only for leaf nodes. */
 		struct {
+			/** WRED packet mode support for current node. */
+			int cman_wred_packet_mode_supported;
+
+			/** WRED byte mode support for current node. */
+			int cman_wred_byte_mode_supported;
+
 			/** Head drop algorithm support for current node. */
 			int cman_head_drop_supported;
 
@@ -791,10 +831,10 @@ enum rte_tm_cman_mode {
  */
 struct rte_tm_red_params {
 	/** Minimum queue threshold */
-	uint16_t min_th;
+	uint32_t min_th;
 
 	/** Maximum queue threshold */
-	uint16_t max_th;
+	uint32_t max_th;
 
 	/** Inverse of packet marking probability maximum value (maxp), i.e.
 	 * maxp_inv = 1 / maxp
@@ -815,10 +855,19 @@ struct rte_tm_red_params {
  * WRED context is used to perform congestion management for a single leaf
  * node, while a shared WRED context is used to perform congestion management
  * for a group of leaf nodes.
+ *
+ * @see struct rte_tm_capabilities::cman_wred_packet_mode_supported
+ * @see struct rte_tm_capabilities::cman_wred_byte_mode_supported
  */
 struct rte_tm_wred_params {
 	/** One set of RED parameters per packet color */
 	struct rte_tm_red_params red_params[RTE_TM_COLORS];
+
+	/** When non-zero, the *min_th* and *max_th* thresholds are specified
+	 * in packets (WRED packet mode). When zero, the *min_th* and *max_th*
+	 * thresholds are specified in bytes (WRED byte mode)
+	 */
+	int packet_mode;
 };
 
 /**
diff --git a/drivers/net/softnic/rte_eth_softnic_tm.c b/drivers/net/softnic/rte_eth_softnic_tm.c
index 79f1c6a..e915c36 100644
--- a/drivers/net/softnic/rte_eth_softnic_tm.c
+++ b/drivers/net/softnic/rte_eth_softnic_tm.c
@@ -479,6 +479,8 @@
 	.sched_wfq_n_groups_max = 1,
 	.sched_wfq_weight_max = UINT32_MAX,
 
+	.cman_wred_packet_mode_supported = WRED_SUPPORTED,
+	.cman_wred_byte_mode_supported = 0,
 	.cman_head_drop_supported = 0,
 	.cman_wred_context_n_max = 0,
 	.cman_wred_context_private_n_max = 0,
@@ -667,6 +669,8 @@
 			.shaper_shared_n_max = 0,
 
 			.cman_head_drop_supported = 0,
+			.cman_wred_packet_mode_supported = WRED_SUPPORTED,
+			.cman_wred_byte_mode_supported = 0,
 			.cman_wred_context_private_supported = WRED_SUPPORTED,
 			.cman_wred_context_shared_n_max = 0,
 
@@ -828,6 +832,8 @@
 
 		{.leaf = {
 			.cman_head_drop_supported = 0,
+			.cman_wred_packet_mode_supported = WRED_SUPPORTED,
+			.cman_wred_byte_mode_supported = 0,
 			.cman_wred_context_private_supported = WRED_SUPPORTED,
 			.cman_wred_context_shared_n_max = 0,
 		} },
@@ -1226,6 +1232,14 @@
 			NULL,
 			rte_strerror(EINVAL));
 
+	/* WRED profile should be in packet mode */
+	if (profile->packet_mode == 0)
+		return -rte_tm_error_set(error,
+			ENOTSUP,
+			RTE_TM_ERROR_TYPE_WRED_PROFILE,
+			NULL,
+			rte_strerror(ENOTSUP));
+
 	/* WRED profile must not exist. */
 	wp = tm_wred_profile_search(dev, wred_profile_id);
 	if (wp)
@@ -1248,6 +1262,14 @@
 		uint16_t min_th = profile->red_params[color].min_th;
 		uint16_t max_th = profile->red_params[color].max_th;
 
+		if (profile->red_params[color].min_th >= (1 << 16) ||
+				profile->red_params[color].max_th >= (1 << 16))
+			return -rte_tm_error_set(error,
+						EINVAL,
+						RTE_TM_ERROR_TYPE_WRED_PROFILE,
+						NULL,
+						rte_strerror(EINVAL));
+
 		if (min_th > max_th || max_th == 0)
 			return -rte_tm_error_set(error,
 				EINVAL,
-- 
1.8.3.1