[dpdk-dev] [PATCH v2 8/9] net/mlx5: translate flex item pattern into matcher

[Gregory Etelson <getelson@nvidia.com>]

From: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

The matcher is an steering engine entity that represents
the flow pattern to hardware to match. It order to
provide match on the flex item pattern the appropriate
matcher fields should be configured with values and masks
accordingly.

The flex item related matcher fields is an array of eight
32-bit fields to match with data captured by sample registers
of configured flex parser. One packet field, presented in
item pattern can be split between several sample registers,
and multiple fields can be combined together into single
sample register to optimize hardware resources usage
(number os sample registers is limited), depending on field
modes, widths and offsets. Actual mapping is complicated
and controlled by special translation data, built by PMD
on flex item creation.

Signed-off-by: Gregory Etelson <getelson@nvidia.com>
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/net/mlx5/mlx5.h           |   8 ++
 drivers/net/mlx5/mlx5_flow_flex.c | 223 ++++++++++++++++++++++++++++++
 2 files changed, 231 insertions(+)

diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 18dfa2fc7b..74af88ec19 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -1853,6 +1853,14 @@ int flow_dv_item_release(struct rte_eth_dev *dev,
 		    struct rte_flow_error *error);
 int mlx5_flex_item_port_init(struct rte_eth_dev *dev);
 void mlx5_flex_item_port_cleanup(struct rte_eth_dev *dev);
+void mlx5_flex_flow_translate_item(struct rte_eth_dev *dev, void *matcher,
+				   void *key, const struct rte_flow_item *item,
+				   bool is_inner);
+int mlx5_flex_acquire_index(struct rte_eth_dev *dev,
+			    struct rte_flow_item_flex_handle *handle,
+			    bool acquire);
+int mlx5_flex_release_index(struct rte_eth_dev *dev, int index);
+
 /* Flex parser list callbacks. */
 struct mlx5_list_entry *mlx5_flex_parser_create_cb(void *list_ctx, void *ctx);
 int mlx5_flex_parser_match_cb(void *list_ctx,
diff --git a/drivers/net/mlx5/mlx5_flow_flex.c b/drivers/net/mlx5/mlx5_flow_flex.c
index b4a9f1a537..bdfa383c45 100644
--- a/drivers/net/mlx5/mlx5_flow_flex.c
+++ b/drivers/net/mlx5/mlx5_flow_flex.c
@@ -113,6 +113,229 @@ mlx5_flex_free(struct mlx5_priv *priv, struct mlx5_flex_item *item)
 	}
 }
 
+static uint32_t
+mlx5_flex_get_bitfield(const struct rte_flow_item_flex *item,
+		       uint32_t pos, uint32_t width, uint32_t shift)
+{
+	const uint8_t *ptr = item->pattern + pos / CHAR_BIT;
+	uint32_t val, vbits;
+
+	/* Proceed the bitfield start byte. */
+	MLX5_ASSERT(width <= sizeof(uint32_t) * CHAR_BIT && width);
+	MLX5_ASSERT(width + shift <= sizeof(uint32_t) * CHAR_BIT);
+	if (item->length <= pos / CHAR_BIT)
+		return 0;
+	val = *ptr++ >> (pos % CHAR_BIT);
+	vbits = CHAR_BIT - pos % CHAR_BIT;
+	pos = (pos + vbits) / CHAR_BIT;
+	vbits = RTE_MIN(vbits, width);
+	val &= RTE_BIT32(vbits) - 1;
+	while (vbits < width && pos < item->length) {
+		uint32_t part = RTE_MIN(width - vbits, (uint32_t)CHAR_BIT);
+		uint32_t tmp = *ptr++;
+
+		pos++;
+		tmp &= RTE_BIT32(part) - 1;
+		val |= tmp << vbits;
+		vbits += part;
+	}
+	return rte_bswap32(val <<= shift);
+}
+
+#define SET_FP_MATCH_SAMPLE_ID(x, def, msk, val, sid) \
+	do { \
+		uint32_t tmp, out = (def); \
+		tmp = MLX5_GET(fte_match_set_misc4, misc4_v, \
+			       prog_sample_field_value_##x); \
+		tmp = (tmp & ~out) | (val); \
+		MLX5_SET(fte_match_set_misc4, misc4_v, \
+			 prog_sample_field_value_##x, tmp); \
+		tmp = MLX5_GET(fte_match_set_misc4, misc4_m, \
+			       prog_sample_field_value_##x); \
+		tmp = (tmp & ~out) | (msk); \
+		MLX5_SET(fte_match_set_misc4, misc4_m, \
+			 prog_sample_field_value_##x, tmp); \
+		tmp = tmp ? (sid) : 0; \
+		MLX5_SET(fte_match_set_misc4, misc4_v, \
+			 prog_sample_field_id_##x, tmp);\
+		MLX5_SET(fte_match_set_misc4, misc4_m, \
+			 prog_sample_field_id_##x, tmp); \
+	} while (0)
+
+__rte_always_inline static void
+mlx5_flex_set_match_sample(void *misc4_m, void *misc4_v,
+			   uint32_t def, uint32_t mask, uint32_t value,
+			   uint32_t sample_id, uint32_t id)
+{
+	switch (id) {
+	case 0:
+		SET_FP_MATCH_SAMPLE_ID(0, def, mask, value, sample_id);
+		break;
+	case 1:
+		SET_FP_MATCH_SAMPLE_ID(1, def, mask, value, sample_id);
+		break;
+	case 2:
+		SET_FP_MATCH_SAMPLE_ID(2, def, mask, value, sample_id);
+		break;
+	case 3:
+		SET_FP_MATCH_SAMPLE_ID(3, def, mask, value, sample_id);
+		break;
+	case 4:
+		SET_FP_MATCH_SAMPLE_ID(4, def, mask, value, sample_id);
+		break;
+	case 5:
+		SET_FP_MATCH_SAMPLE_ID(5, def, mask, value, sample_id);
+		break;
+	case 6:
+		SET_FP_MATCH_SAMPLE_ID(6, def, mask, value, sample_id);
+		break;
+	case 7:
+		SET_FP_MATCH_SAMPLE_ID(7, def, mask, value, sample_id);
+		break;
+	default:
+		MLX5_ASSERT(false);
+		break;
+	}
+#undef SET_FP_MATCH_SAMPLE_ID
+}
+/**
+ * Translate item pattern into matcher fields according to translation
+ * array.
+ *
+ * @param dev
+ *   Ethernet device to translate flex item on.
+ * @param[in, out] matcher
+ *   Flow matcher to confgiure
+ * @param[in, out] key
+ *   Flow matcher value.
+ * @param[in] item
+ *   Flow pattern to translate.
+ * @param[in] is_inner
+ *   Inner Flex Item (follows after tunnel header).
+ *
+ * @return
+ *   0 on success, a negative errno value otherwise and rte_errno is set.
+ */
+void
+mlx5_flex_flow_translate_item(struct rte_eth_dev *dev,
+			      void *matcher, void *key,
+			      const struct rte_flow_item *item,
+			      bool is_inner)
+{
+#ifdef RTE_LIBRTE_MLX5_DEBUG
+	struct mlx5_priv *priv = dev->data->dev_private;
+#endif
+	const struct rte_flow_item_flex *spec, *mask;
+	void *misc4_m = MLX5_ADDR_OF(fte_match_param, matcher,
+				     misc_parameters_4);
+	void *misc4_v = MLX5_ADDR_OF(fte_match_param, key, misc_parameters_4);
+	struct mlx5_flex_item *tp;
+	uint32_t i, pos = 0;
+
+	RTE_SET_USED(dev);
+	MLX5_ASSERT(item->spec && item->mask);
+	spec = item->spec;
+	mask = item->mask;
+	tp = (struct mlx5_flex_item *)spec->handle;
+	MLX5_ASSERT(mlx5_flex_index(priv, tp) >= 0);
+	for (i = 0; i < tp->mapnum; i++) {
+		struct mlx5_flex_pattern_field *map = tp->map + i;
+		uint32_t id = map->reg_id;
+		uint32_t def = (RTE_BIT64(map->width) - 1) << map->shift;
+		uint32_t val, msk;
+
+		/* Skip placeholders for DUMMY fields. */
+		if (id == MLX5_INVALID_SAMPLE_REG_ID) {
+			pos += map->width;
+			continue;
+		}
+		val = mlx5_flex_get_bitfield(spec, pos, map->width, map->shift);
+		msk = mlx5_flex_get_bitfield(mask, pos, map->width, map->shift);
+		MLX5_ASSERT(map->width);
+		MLX5_ASSERT(id < tp->devx_fp->num_samples);
+		if (tp->tunnel_mode == FLEX_TUNNEL_MODE_MULTI && is_inner) {
+			uint32_t num_samples = tp->devx_fp->num_samples / 2;
+
+			MLX5_ASSERT(tp->devx_fp->num_samples % 2 == 0);
+			MLX5_ASSERT(id < num_samples);
+			id += num_samples;
+		}
+		mlx5_flex_set_match_sample(misc4_m, misc4_v,
+					   def, msk & def, val & msk & def,
+					   tp->devx_fp->sample_ids[id], id);
+		pos += map->width;
+	}
+}
+
+/**
+ * Convert flex item handle (from the RTE flow) to flex item index on port.
+ * Optionally can increment flex item object reference count.
+ *
+ * @param dev
+ *   Ethernet device to acquire flex item on.
+ * @param[in] handle
+ *   Flow item handle from item spec.
+ * @param[in] acquire
+ *   If set - increment reference counter.
+ *
+ * @return
+ *   >=0 - index on success, a negative errno value otherwise
+ *         and rte_errno is set.
+ */
+int
+mlx5_flex_acquire_index(struct rte_eth_dev *dev,
+			struct rte_flow_item_flex_handle *handle,
+			bool acquire)
+{
+	struct mlx5_priv *priv = dev->data->dev_private;
+	struct mlx5_flex_item *flex = (struct mlx5_flex_item *)handle;
+	int ret = mlx5_flex_index(priv, flex);
+
+	if (ret < 0) {
+		errno = -EINVAL;
+		rte_errno = EINVAL;
+		return ret;
+	}
+	if (acquire)
+		__atomic_add_fetch(&flex->refcnt, 1, __ATOMIC_RELEASE);
+	return ret;
+}
+
+/**
+ * Release flex item index on port - decrements reference counter by index.
+ *
+ * @param dev
+ *   Ethernet device to acquire flex item on.
+ * @param[in] index
+ *   Flow item index.
+ *
+ * @return
+ *   0 - on success, a negative errno value otherwise and rte_errno is set.
+ */
+int
+mlx5_flex_release_index(struct rte_eth_dev *dev,
+			int index)
+{
+	struct mlx5_priv *priv = dev->data->dev_private;
+	struct mlx5_flex_item *flex;
+
+	if (index >= MLX5_PORT_FLEX_ITEM_NUM ||
+	    !(priv->flex_item_map & (1u << index))) {
+		errno = EINVAL;
+		rte_errno = -EINVAL;
+		return -EINVAL;
+	}
+	flex = priv->flex_item + index;
+	if (flex->refcnt <= 1) {
+		MLX5_ASSERT(false);
+		errno = EINVAL;
+		rte_errno = -EINVAL;
+		return -EINVAL;
+	}
+	__atomic_sub_fetch(&flex->refcnt, 1, __ATOMIC_RELEASE);
+	return 0;
+}
+
 /*
  * Calculate largest mask value for a given shift.
  *
-- 
2.33.1