[dpdk-dev] [RFC 05/10] net/mlx5: add IB shared context alloc/free functions

[Viacheslav Ovsiienko]

The functions to allocate and free shared IB context for
multiport is added. The IB device context, Protection
Domain, device attributes, Infiniband names are going
to be relocated to the shared structure from the device
private one. mlx5_dev_spawn() is updated to create shared
context.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo at mellanox.com>
---
 drivers/net/mlx5/mlx5.c | 232 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 174 insertions(+), 58 deletions(-)

diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index c6ddeb3..4df6496 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -141,6 +141,148 @@ struct mlx5_dev_spawn_data {
 	struct rte_eth_dev *eth_dev; /**< Associated Ethernet device. */
 };
 
+static LIST_HEAD(, mlx5_ibv_shared) mlx5_ibv_list = LIST_HEAD_INITIALIZER();
+
+/**
+ * Allocate shared IB device context. If there is multiport device the
+ * master and representors will share this context, if there is single
+ * port dedicated IB device, the context will be used by only given
+ * port due to unification.
+ *
+ * Routine first searches the context for the spesified IB device name,
+ * if found the shared context assumed and reference counter is incremented.
+ * If no context found the new one is created and initialized with specified
+ * IB device context and parameters.
+ *
+ * @param[in] spawn
+ *   Pointer to the IB device attributes (name, port, etc).
+ *
+ * @return
+ *   Pointer to mlx5_ibv_shared object on success,
+ *   otherwise NULL and rte_errno is set.
+ */
+static struct mlx5_ibv_shared *
+mlx5_alloc_shared_ibctx(const struct mlx5_dev_spawn_data *spawn)
+{
+	struct mlx5_ibv_shared *sh;
+	int err = 0;
+
+	assert(spawn);
+	/* Search for IB context by device name. */
+	LIST_FOREACH(sh, &mlx5_ibv_list, next) {
+		if (!strcmp(sh->ibdev_name, spawn->ibv_dev->name)) {
+			assert(!sh->secondary);
+			sh->refcnt++;
+			return sh;
+		}
+	}
+	/* No device found, we have to create new sharted context. */
+	assert(spawn->max_port);
+	sh = rte_zmalloc("ethdev shared ib context",
+			 sizeof(struct mlx5_ibv_shared) +
+			 spawn->max_port *
+			 sizeof(struct mlx5_ibv_shared_port),
+			 RTE_CACHE_LINE_SIZE);
+	if (!sh) {
+		DRV_LOG(ERR, "shared context allocation failure");
+		rte_errno  = ENOMEM;
+		return NULL;
+	}
+	/* Try to open IB device with DV first, then usual Verbs. */
+	errno = 0;
+	sh->ctx = mlx5_glue->dv_open_device(spawn->ibv_dev);
+	if (sh->ctx) {
+		sh->devx = 1;
+		DRV_LOG(DEBUG, "DevX is supported");
+	} else {
+		sh->ctx = mlx5_glue->open_device(spawn->ibv_dev);
+		if (!sh->ctx) {
+			err = errno ? errno : ENODEV;
+			goto error;
+		}
+		DRV_LOG(DEBUG, "DevX is NOT supported");
+	}
+	err = mlx5_glue->query_device_ex(sh->ctx, NULL, &sh->device_attr);
+	if (err) {
+		DRV_LOG(DEBUG, "ibv_query_device_ex() failed");
+		goto error;
+	}
+	sh->refcnt = 1;
+	sh->max_port = spawn->max_port;
+	strncpy(sh->ibdev_name, sh->ctx->device->name,
+		sizeof(sh->ibdev_name));
+	strncpy(sh->ibdev_path, sh->ctx->device->ibdev_path,
+		sizeof(sh->ibdev_path));
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+		/*
+		 * For secondary process we just open the IB device
+		 * and get attributes, there will no be real usage
+		 * of this structure, the secondary process will
+		 * use one from prpimary.
+		 */
+		sh->secondary = 1;
+		return sh;
+	}
+	sh->pd = mlx5_glue->alloc_pd(sh->ctx);
+	if (sh->pd == NULL) {
+		DRV_LOG(ERR, "PD allocation failure");
+		err = ENOMEM;
+		goto error;
+	}
+	return sh;
+error:
+	assert(sh);
+	if (sh->pd)
+		claim_zero(mlx5_glue->dealloc_pd(sh->pd));
+	if (sh->ctx)
+		claim_zero(mlx5_glue->close_device(sh->ctx));
+	rte_free(sh);
+	assert(err > 0);
+	rte_errno = err;
+	return NULL;
+}
+
+/**
+ * Free shared IB device context. Decrement counter and if zero free
+ * all allocated resources and close handles.
+ *
+ * @param[in] sh
+ *   Pointer to mlx5_ibv_shared object to free
+ */
+static void
+mlx5_free_shared_ibctx(struct mlx5_ibv_shared *sh)
+{
+#ifndef NDEBUG
+	/* Check the object presence in the list. */
+	struct mlx5_ibv_shared *lctx;
+
+	LIST_FOREACH(lctx, &mlx5_ibv_list, next)
+		if (lctx == sh)
+			break;
+	assert(lctx);
+	if (lctx != sh) {
+		DRV_LOG(ERR, "Freeing non-existing shared IB context");
+		return;
+	}
+#endif
+	assert(sh);
+	assert(sh->refcnt);
+	if (--sh->refcnt)
+		return;
+	/* Zero reference counter, we should release resources. */
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+		assert(sh->secondary);
+		assert(sh->ctx);
+		assert(!sh->pd);
+	}
+	if (sh->pd)
+		claim_zero(mlx5_glue->dealloc_pd(sh->pd));
+	if (sh->ctx)
+		claim_zero(mlx5_glue->close_device(sh->ctx));
+	rte_free(sh);
+}
+
+
 /**
  * Prepare shared data between primary and secondary process.
  */
@@ -290,12 +432,10 @@ struct mlx5_dev_spawn_data {
 	}
 	mlx5_mprq_free_mp(dev);
 	mlx5_mr_release(dev);
-	if (priv->pd != NULL) {
-		assert(priv->ctx != NULL);
-		claim_zero(mlx5_glue->dealloc_pd(priv->pd));
-		claim_zero(mlx5_glue->close_device(priv->ctx));
-	} else
-		assert(priv->ctx == NULL);
+	assert(priv->sh);
+	if (priv->sh)
+		mlx5_free_shared_ibctx(priv->sh);
+	priv->sh = NULL;
 	if (priv->rss_conf.rss_key != NULL)
 		rte_free(priv->rss_conf.rss_key);
 	if (priv->reta_idx != NULL)
@@ -745,11 +885,8 @@ struct mlx5_dev_spawn_data {
 	       struct mlx5_dev_config config)
 {
 	const struct mlx5_switch_info *switch_info = &spawn->info;
-	struct ibv_device *ibv_dev = spawn->ibv_dev;
-	struct ibv_context *ctx = NULL;
-	struct ibv_device_attr_ex attr;
+	struct mlx5_ibv_shared *sh;
 	struct ibv_port_attr port_attr;
-	struct ibv_pd *pd = NULL;
 	struct mlx5dv_context dv_attr = { .comp_mask = 0 };
 	struct rte_eth_dev *eth_dev = NULL;
 	struct mlx5_priv *priv = NULL;
@@ -805,18 +942,10 @@ struct mlx5_dev_spawn_data {
 	}
 	/* Prepare shared data between primary and secondary process. */
 	mlx5_prepare_shared_data();
-	errno = 0;
-	ctx = mlx5_glue->dv_open_device(ibv_dev);
-	if (ctx) {
-		config.devx = 1;
-		DRV_LOG(DEBUG, "DEVX is supported");
-	} else {
-		ctx = mlx5_glue->open_device(ibv_dev);
-		if (!ctx) {
-			rte_errno = errno ? errno : ENODEV;
-			return NULL;
-		}
-	}
+	sh = mlx5_alloc_shared_ibctx(spawn);
+	if (!sh)
+		return NULL;
+	config.devx = sh->devx;
 #ifdef HAVE_IBV_MLX5_MOD_SWP
 	dv_attr.comp_mask |= MLX5DV_CONTEXT_MASK_SWP;
 #endif
@@ -830,7 +959,7 @@ struct mlx5_dev_spawn_data {
 #ifdef HAVE_IBV_DEVICE_STRIDING_RQ_SUPPORT
 	dv_attr.comp_mask |= MLX5DV_CONTEXT_MASK_STRIDING_RQ;
 #endif
-	mlx5_glue->dv_query_device(ctx, &dv_attr);
+	mlx5_glue->dv_query_device(sh->ctx, &dv_attr);
 	if (dv_attr.flags & MLX5DV_CONTEXT_FLAGS_MPW_ALLOWED) {
 		if (dv_attr.flags & MLX5DV_CONTEXT_FLAGS_ENHANCED_MPW) {
 			DRV_LOG(DEBUG, "enhanced MPW is supported");
@@ -915,11 +1044,6 @@ struct mlx5_dev_spawn_data {
 		" old OFED/rdma-core version or firmware configuration");
 #endif
 	config.mpls_en = mpls_en;
-	err = mlx5_glue->query_device_ex(ctx, NULL, &attr);
-	if (err) {
-		DEBUG("ibv_query_device_ex() failed");
-		goto error;
-	}
 	DRV_LOG(DEBUG, "naming Ethernet device \"%s\"", name);
 	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
 		eth_dev = rte_eth_dev_attach_secondary(name);
@@ -955,11 +1079,11 @@ struct mlx5_dev_spawn_data {
 		 */
 		eth_dev->rx_pkt_burst = mlx5_select_rx_function(eth_dev);
 		eth_dev->tx_pkt_burst = mlx5_select_tx_function(eth_dev);
-		claim_zero(mlx5_glue->close_device(ctx));
+		mlx5_free_shared_ibctx(sh);
 		return eth_dev;
 	}
 	/* Check port status. */
-	err = mlx5_glue->query_port(ctx, spawn->ibv_port, &port_attr);
+	err = mlx5_glue->query_port(sh->ctx, spawn->ibv_port, &port_attr);
 	if (err) {
 		DRV_LOG(ERR, "port query failed: %s", strerror(err));
 		goto error;
@@ -973,13 +1097,7 @@ struct mlx5_dev_spawn_data {
 		DRV_LOG(DEBUG, "port is not active: \"%s\" (%d)",
 			mlx5_glue->port_state_str(port_attr.state),
 			port_attr.state);
-	/* Allocate protection domain. */
-	pd = mlx5_glue->alloc_pd(ctx);
-	if (pd == NULL) {
-		DRV_LOG(ERR, "PD allocation failure");
-		err = ENOMEM;
-		goto error;
-	}
+	/* Allocate private eth device data. */
 	priv = rte_zmalloc("ethdev private structure",
 			   sizeof(*priv),
 			   RTE_CACHE_LINE_SIZE);
@@ -988,13 +1106,11 @@ struct mlx5_dev_spawn_data {
 		err = ENOMEM;
 		goto error;
 	}
-	priv->ctx = ctx;
-	strncpy(priv->ibdev_name, priv->ctx->device->name,
-		sizeof(priv->ibdev_name));
-	strncpy(priv->ibdev_path, priv->ctx->device->ibdev_path,
-		sizeof(priv->ibdev_path));
-	priv->device_attr = attr;
-	priv->pd = pd;
+	priv->sh = sh;
+	priv->ctx = sh->ctx;
+	priv->ibv_port = spawn->ibv_port;
+	priv->device_attr = sh->device_attr;
+	priv->pd = sh->pd;
 	priv->mtu = ETHER_MTU;
 #ifndef RTE_ARCH_64
 	/* Initialize UAR access locks for 32bit implementations. */
@@ -1048,7 +1164,8 @@ struct mlx5_dev_spawn_data {
 			strerror(rte_errno));
 		goto error;
 	}
-	config.hw_csum = !!(attr.device_cap_flags_ex & IBV_DEVICE_RAW_IP_CSUM);
+	config.hw_csum = !!(sh->device_attr.device_cap_flags_ex &
+			    IBV_DEVICE_RAW_IP_CSUM);
 	DRV_LOG(DEBUG, "checksum offloading is %ssupported",
 		(config.hw_csum ? "" : "not "));
 #if !defined(HAVE_IBV_DEVICE_COUNTERS_SET_V42) && \
@@ -1062,7 +1179,7 @@ struct mlx5_dev_spawn_data {
 	}
 #endif
 	config.ind_table_max_size =
-		attr.rss_caps.max_rwq_indirection_table_size;
+		sh->device_attr.rss_caps.max_rwq_indirection_table_size;
 	/*
 	 * Remove this check once DPDK supports larger/variable
 	 * indirection tables.
@@ -1071,18 +1188,18 @@ struct mlx5_dev_spawn_data {
 		config.ind_table_max_size = ETH_RSS_RETA_SIZE_512;
 	DRV_LOG(DEBUG, "maximum Rx indirection table size is %u",
 		config.ind_table_max_size);
-	config.hw_vlan_strip = !!(attr.raw_packet_caps &
+	config.hw_vlan_strip = !!(sh->device_attr.raw_packet_caps &
 				  IBV_RAW_PACKET_CAP_CVLAN_STRIPPING);
 	DRV_LOG(DEBUG, "VLAN stripping is %ssupported",
 		(config.hw_vlan_strip ? "" : "not "));
-	config.hw_fcs_strip = !!(attr.raw_packet_caps &
+	config.hw_fcs_strip = !!(sh->device_attr.raw_packet_caps &
 				 IBV_RAW_PACKET_CAP_SCATTER_FCS);
 	DRV_LOG(DEBUG, "FCS stripping configuration is %ssupported",
 		(config.hw_fcs_strip ? "" : "not "));
 #if defined(HAVE_IBV_WQ_FLAG_RX_END_PADDING)
-	hw_padding = !!attr.rx_pad_end_addr_align;
+	hw_padding = !!sh->device_attr.rx_pad_end_addr_align;
 #elif defined(HAVE_IBV_WQ_FLAGS_PCI_WRITE_END_PADDING)
-	hw_padding = !!(attr.device_cap_flags_ex &
+	hw_padding = !!(sh->device_attr.device_cap_flags_ex &
 			IBV_DEVICE_PCI_WRITE_END_PADDING);
 #endif
 	if (config.hw_padding && !hw_padding) {
@@ -1091,11 +1208,11 @@ struct mlx5_dev_spawn_data {
 	} else if (config.hw_padding) {
 		DRV_LOG(DEBUG, "Rx end alignment padding is enabled");
 	}
-	config.tso = (attr.tso_caps.max_tso > 0 &&
-		      (attr.tso_caps.supported_qpts &
+	config.tso = (sh->device_attr.tso_caps.max_tso > 0 &&
+		      (sh->device_attr.tso_caps.supported_qpts &
 		       (1 << IBV_QPT_RAW_PACKET)));
 	if (config.tso)
-		config.tso_max_payload_sz = attr.tso_caps.max_tso;
+		config.tso_max_payload_sz = sh->device_attr.tso_caps.max_tso;
 	/*
 	 * MPW is disabled by default, while the Enhanced MPW is enabled
 	 * by default.
@@ -1236,7 +1353,8 @@ struct mlx5_dev_spawn_data {
 		.free = &mlx5_free_verbs_buf,
 		.data = priv,
 	};
-	mlx5_glue->dv_set_context_attr(ctx, MLX5DV_CTX_ATTR_BUF_ALLOCATORS,
+	mlx5_glue->dv_set_context_attr(sh->ctx,
+				       MLX5DV_CTX_ATTR_BUF_ALLOCATORS,
 				       (void *)((uintptr_t)&alctr));
 	/* Bring Ethernet device up. */
 	DRV_LOG(DEBUG, "port %u forcing Ethernet interface up",
@@ -1290,15 +1408,13 @@ struct mlx5_dev_spawn_data {
 		if (eth_dev != NULL)
 			eth_dev->data->dev_private = NULL;
 	}
-	if (pd)
-		claim_zero(mlx5_glue->dealloc_pd(pd));
 	if (eth_dev != NULL) {
 		/* mac_addrs must not be freed alone because part of dev_private */
 		eth_dev->data->mac_addrs = NULL;
 		rte_eth_dev_release_port(eth_dev);
 	}
-	if (ctx)
-		claim_zero(mlx5_glue->close_device(ctx));
+	if (sh)
+		mlx5_free_shared_ibctx(sh);
 	assert(err > 0);
 	rte_errno = err;
 	return NULL;
-- 
1.8.3.1