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

  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(-)
  

> -----Original Message-----
> From: Rao, Nikhil
> Sent: Tuesday, February 20, 2018 1:31 PM
> To: Dumitrescu, Cristian <cristian.dumitrescu@intel.com>
> Cc: dev@dpdk.org; Shelton, Benjamin H <benjamin.h.shelton@intel.com>;
> Vangati, Narender <narender.vangati@intel.com>; Gujjar, Abhinandan S
> <abhinandan.gujjar@intel.com>; Rao, Nikhil <nikhil.rao@intel.com>
> Subject: [PATCH] ethdev: add support for WRED thresholds in bytes
> 
> 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

Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>

Applied to next-qos tree with some minor adjustments in file rte_eth_softnic_tm.c:
- moved check on profile->packet_mode after the check that profile is not NULL
- consolidated checks on min_th and max_th under a single block
- replaced 1 << 16 with UINT16_MAX

Thanks!