[dpdk-dev] [PATCH v2 03/19] net/mlx5: allocate flow meter registers

[Suanming Mou <suanmingm@mellanox.com>]

Meter need the metadata REG_C to have the color match between the prefix
flow and the meter flow.

As the user define or metadata feature will both use the REG_C in the
suffix flow, the color match register meter uses will not impact the
register use in the later sub flow.

Another case is that tag is add before meter flow. In this case, meter
should not touch the register the tag action is using. To avoid that
case, meter should reserve the REG_C's used by user defined MLX5_APP_TAG.

Signed-off-by: Suanming Mou <suanmingm@mellanox.com>
---
 drivers/net/mlx5/mlx5.c      | 20 ++++++++++++++-
 drivers/net/mlx5/mlx5.h      |  2 ++
 drivers/net/mlx5/mlx5_flow.c | 60 +++++++++++++++++++++++++++++++++-----------
 drivers/net/mlx5/mlx5_flow.h |  2 ++
 4 files changed, 68 insertions(+), 16 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 1adef85..3b30169 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -2293,7 +2293,25 @@ struct mlx5_flow_id_pool *
 #if defined(HAVE_MLX5DV_DR) && defined(HAVE_MLX5_DR_CREATE_ACTION_FLOW_METER)
 		if (config.hca_attr.qos.sup && config.hca_attr.qos.srtcm_sup &&
 		    config.dv_flow_en) {
-			priv->mtr_en = 1;
+			uint8_t reg_c_mask =
+				config.hca_attr.qos.flow_meter_reg_c_ids;
+			/*
+			 * Meter needs two REG_C's for color match and pre-sfx
+			 * flow match. Here get the REG_C for color match.
+			 * REG_C_0 and REG_C_1 is reserved for metadata feature.
+			 */
+			reg_c_mask &= 0xfc;
+			if (__builtin_popcount(reg_c_mask) < 1) {
+				priv->mtr_en = 0;
+				DRV_LOG(WARNING, "No available register for"
+					" meter.");
+			} else {
+				priv->mtr_color_reg = ffs(reg_c_mask) - 1 +
+						      REG_C_0;
+				priv->mtr_en = 1;
+				DRV_LOG(DEBUG, "The REG_C meter uses is %d",
+					priv->mtr_color_reg);
+			}
 		}
 #endif
 	}
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index be2f23d..f19ea23 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -752,6 +752,8 @@ struct mlx5_priv {
 	struct mlx5_flow_id_pool *qrss_id_pool;
 	struct mlx5_hlist *mreg_cp_tbl;
 	/* Hash table of Rx metadata register copy table. */
+	uint8_t mtr_sfx_reg; /* Meter prefix-suffix flow match REG_C. */
+	uint8_t mtr_color_reg; /* Meter color match REG_C. */
 #ifndef RTE_ARCH_64
 	rte_spinlock_t uar_lock_cq; /* CQs share a common distinct UAR */
 	rte_spinlock_t uar_lock[MLX5_UAR_PAGE_NUM_MAX];
diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 61afc48..b8abe6a 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -344,6 +344,7 @@ enum modify_reg
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
 	struct mlx5_dev_config *config = &priv->config;
+	enum modify_reg start_reg;
 
 	switch (feature) {
 	case MLX5_HAIRPIN_RX:
@@ -375,24 +376,53 @@ enum modify_reg
 		}
 		break;
 	case MLX5_COPY_MARK:
-		return REG_C_3;
+	case MLX5_MTR_SFX:
+		/*
+		 * Metadata COPY_MARK register using is in meter suffix sub
+		 * flow while with meter. It's safe to share the same register.
+		 */
+		return priv->mtr_color_reg != REG_C_2 ? REG_C_2 : REG_C_3;
+	case MLX5_MTR_COLOR:
+		RTE_ASSERT(priv->mtr_color_reg != REG_NONE);
+		return priv->mtr_color_reg;
 	case MLX5_APP_TAG:
 		/*
-		 * Suppose engaging reg_c_2 .. reg_c_7 registers.
-		 * reg_c_2 is reserved for coloring by meters.
-		 * reg_c_3 is reserved for split flows TAG.
+		 * If meter is enable, it will engage two registers for color
+		 * match and flow match. If meter color match is not using the
+		 * REG_C_2, need to skip the REG_C_x be used by meter color
+		 * match.
+		 * If meter is disable, free to use all available registers.
 		 */
-		if (id > (REG_C_7 - REG_C_4))
-			return rte_flow_error_set
-					(error, EINVAL,
-					 RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-					 NULL, "invalid tag id");
-		if (config->flow_mreg_c[id + REG_C_4 - REG_C_0] == REG_NONE)
-			return rte_flow_error_set
-					(error, ENOTSUP,
-					 RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
-					 NULL, "unsupported tag id");
-		return config->flow_mreg_c[id + REG_C_4 - REG_C_0];
+		if (priv->mtr_color_reg != REG_NONE)
+			start_reg = priv->mtr_color_reg != REG_C_2 ? REG_C_3 :
+				    REG_C_4;
+		else
+			start_reg = REG_C_2;
+		if (id > (REG_C_7 - start_reg))
+			return rte_flow_error_set(error, EINVAL,
+						  RTE_FLOW_ERROR_TYPE_ITEM,
+						  NULL, "invalid tag id");
+		if (config->flow_mreg_c[id + start_reg - REG_C_0] == REG_NONE)
+			return rte_flow_error_set(error, ENOTSUP,
+						  RTE_FLOW_ERROR_TYPE_ITEM,
+						  NULL, "unsupported tag id");
+		/*
+		 * This case means meter is using the REG_C_x great than 2.
+		 * Take care not to conflict with meter color REG_C_x.
+		 * If the available index REG_C_y >= REG_C_x, skip the
+		 * color register.
+		 */
+		if (start_reg == REG_C_3 && config->flow_mreg_c
+		    [id + REG_C_3 - REG_C_0] >= priv->mtr_color_reg) {
+			if (config->flow_mreg_c[id + 1 + REG_C_3 - REG_C_0] !=
+			    REG_NONE)
+				return config->flow_mreg_c
+						[id + 1 + REG_C_3 - REG_C_0];
+			return rte_flow_error_set(error, ENOTSUP,
+						  RTE_FLOW_ERROR_TYPE_ITEM,
+						  NULL, "unsupported tag id");
+		}
+		return config->flow_mreg_c[id + start_reg - REG_C_0];
 	}
 	assert(false);
 	return rte_flow_error_set(error, EINVAL,
diff --git a/drivers/net/mlx5/mlx5_flow.h b/drivers/net/mlx5/mlx5_flow.h
index f84ea9d..ac1675456 100644
--- a/drivers/net/mlx5/mlx5_flow.h
+++ b/drivers/net/mlx5/mlx5_flow.h
@@ -74,6 +74,8 @@ enum mlx5_feature_name {
 	MLX5_FLOW_MARK,
 	MLX5_APP_TAG,
 	MLX5_COPY_MARK,
+	MLX5_MTR_COLOR,
+	MLX5_MTR_SFX,
 };
 
 /* Pattern outer Layer bits. */
-- 
1.8.3.1