Merge branch 'mlxsw-SPAN-cleanups'

Jiri Pirko says:

====================
mlxsw: SPAN cleanups

In patch one of this short series, a misplaced pointer star is moved to
the correct place.

In the second patch, we observe that if SPAN entries carry their
reference count anyway, it's redundant to also carry a "used" flag.

In the third patch, SPAN support code is moved to a separate module.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -20,7 +20,7 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_cnt.o spectrum_fid.o \
 				   spectrum_ipip.o spectrum_acl_flex_actions.o \
 				   spectrum_mr.o spectrum_mr_tcam.o \
-				   spectrum_qdisc.o
+				   spectrum_qdisc.o spectrum_span.o
 mlxsw_spectrum-$(CONFIG_MLXSW_SPECTRUM_DCB)	+= spectrum_dcb.o
 mlxsw_spectrum-$(CONFIG_NET_DEVLINK) += spectrum_dpipe.o
 obj-$(CONFIG_MLXSW_MINIMAL)	+= mlxsw_minimal.o

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -71,6 +71,7 @@
 #include "spectrum_cnt.h"
 #include "spectrum_dpipe.h"
 #include "spectrum_acl_flex_actions.h"
+#include "spectrum_span.h"
 #include "../mlxfw/mlxfw.h"
 
 #define MLXSW_FWREV_MAJOR 13
@@ -487,327 +488,6 @@ static int mlxsw_sp_base_mac_get(struct mlxsw_sp *mlxsw_sp)
 	return 0;
 }
 
-static int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp)
-{
-	int i;
-
-	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_SPAN))
-		return -EIO;
-
-	mlxsw_sp->span.entries_count = MLXSW_CORE_RES_GET(mlxsw_sp->core,
-							  MAX_SPAN);
-	mlxsw_sp->span.entries = kcalloc(mlxsw_sp->span.entries_count,
-					 sizeof(struct mlxsw_sp_span_entry),
-					 GFP_KERNEL);
-	if (!mlxsw_sp->span.entries)
-		return -ENOMEM;
-
-	for (i = 0; i < mlxsw_sp->span.entries_count; i++)
-		INIT_LIST_HEAD(&mlxsw_sp->span.entries[i].bound_ports_list);
-
-	return 0;
-}
-
-static void mlxsw_sp_span_fini(struct mlxsw_sp *mlxsw_sp)
-{
-	int i;
-
-	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
-		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
-
-		WARN_ON_ONCE(!list_empty(&curr->bound_ports_list));
-	}
-	kfree(mlxsw_sp->span.entries);
-}
-
-static struct mlxsw_sp_span_entry *
-mlxsw_sp_span_entry_create(struct mlxsw_sp_port *port)
-{
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	struct mlxsw_sp_span_entry *span_entry;
-	char mpat_pl[MLXSW_REG_MPAT_LEN];
-	u8 local_port = port->local_port;
-	int index;
-	int i;
-	int err;
-
-	/* find a free entry to use */
-	index = -1;
-	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
-		if (!mlxsw_sp->span.entries[i].used) {
-			index = i;
-			span_entry = &mlxsw_sp->span.entries[i];
-			break;
-		}
-	}
-	if (index < 0)
-		return NULL;
-
-	/* create a new port analayzer entry for local_port */
-	mlxsw_reg_mpat_pack(mpat_pl, index, local_port, true);
-	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpat), mpat_pl);
-	if (err)
-		return NULL;
-
-	span_entry->used = true;
-	span_entry->id = index;
-	span_entry->ref_count = 1;
-	span_entry->local_port = local_port;
-	return span_entry;
-}
-
-static void mlxsw_sp_span_entry_destroy(struct mlxsw_sp *mlxsw_sp,
-					struct mlxsw_sp_span_entry *span_entry)
-{
-	u8 local_port = span_entry->local_port;
-	char mpat_pl[MLXSW_REG_MPAT_LEN];
-	int pa_id = span_entry->id;
-
-	mlxsw_reg_mpat_pack(mpat_pl, pa_id, local_port, false);
-	mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpat), mpat_pl);
-	span_entry->used = false;
-}
-
-struct mlxsw_sp_span_entry *
-mlxsw_sp_span_entry_find(struct mlxsw_sp *mlxsw_sp, u8 local_port)
-{
-	int i;
-
-	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
-		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
-
-		if (curr->used && curr->local_port == local_port)
-			return curr;
-	}
-	return NULL;
-}
-
-static struct mlxsw_sp_span_entry
-*mlxsw_sp_span_entry_get(struct mlxsw_sp_port *port)
-{
-	struct mlxsw_sp_span_entry *span_entry;
-
-	span_entry = mlxsw_sp_span_entry_find(port->mlxsw_sp,
-					      port->local_port);
-	if (span_entry) {
-		/* Already exists, just take a reference */
-		span_entry->ref_count++;
-		return span_entry;
-	}
-
-	return mlxsw_sp_span_entry_create(port);
-}
-
-static int mlxsw_sp_span_entry_put(struct mlxsw_sp *mlxsw_sp,
-				   struct mlxsw_sp_span_entry *span_entry)
-{
-	WARN_ON(!span_entry->ref_count);
-	if (--span_entry->ref_count == 0)
-		mlxsw_sp_span_entry_destroy(mlxsw_sp, span_entry);
-	return 0;
-}
-
-static bool mlxsw_sp_span_is_egress_mirror(struct mlxsw_sp_port *port)
-{
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	struct mlxsw_sp_span_inspected_port *p;
-	int i;
-
-	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
-		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
-
-		list_for_each_entry(p, &curr->bound_ports_list, list)
-			if (p->local_port == port->local_port &&
-			    p->type == MLXSW_SP_SPAN_EGRESS)
-				return true;
-	}
-
-	return false;
-}
-
-static int mlxsw_sp_span_mtu_to_buffsize(const struct mlxsw_sp *mlxsw_sp,
-					 int mtu)
-{
-	return mlxsw_sp_bytes_cells(mlxsw_sp, mtu * 5 / 2) + 1;
-}
-
-static int mlxsw_sp_span_port_mtu_update(struct mlxsw_sp_port *port, u16 mtu)
-{
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	char sbib_pl[MLXSW_REG_SBIB_LEN];
-	int err;
-
-	/* If port is egress mirrored, the shared buffer size should be
-	 * updated according to the mtu value
-	 */
-	if (mlxsw_sp_span_is_egress_mirror(port)) {
-		u32 buffsize = mlxsw_sp_span_mtu_to_buffsize(mlxsw_sp, mtu);
-
-		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, buffsize);
-		err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
-		if (err) {
-			netdev_err(port->dev, "Could not update shared buffer for mirroring\n");
-			return err;
-		}
-	}
-
-	return 0;
-}
-
-static struct mlxsw_sp_span_inspected_port *
-mlxsw_sp_span_entry_bound_port_find(struct mlxsw_sp_port *port,
-				    struct mlxsw_sp_span_entry *span_entry)
-{
-	struct mlxsw_sp_span_inspected_port *p;
-
-	list_for_each_entry(p, &span_entry->bound_ports_list, list)
-		if (port->local_port == p->local_port)
-			return p;
-	return NULL;
-}
-
-static int
-mlxsw_sp_span_inspected_port_bind(struct mlxsw_sp_port *port,
-				  struct mlxsw_sp_span_entry *span_entry,
-				  enum mlxsw_sp_span_type type,
-				  bool bind)
-{
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	char mpar_pl[MLXSW_REG_MPAR_LEN];
-	int pa_id = span_entry->id;
-
-	/* bind the port to the SPAN entry */
-	mlxsw_reg_mpar_pack(mpar_pl, port->local_port,
-			    (enum mlxsw_reg_mpar_i_e) type, bind, pa_id);
-	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpar), mpar_pl);
-}
-
-static int
-mlxsw_sp_span_inspected_port_add(struct mlxsw_sp_port *port,
-				 struct mlxsw_sp_span_entry *span_entry,
-				 enum mlxsw_sp_span_type type,
-				 bool bind)
-{
-	struct mlxsw_sp_span_inspected_port *inspected_port;
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	char sbib_pl[MLXSW_REG_SBIB_LEN];
-	int err;
-
-	/* if it is an egress SPAN, bind a shared buffer to it */
-	if (type == MLXSW_SP_SPAN_EGRESS) {
-		u32 buffsize = mlxsw_sp_span_mtu_to_buffsize(mlxsw_sp,
-							     port->dev->mtu);
-
-		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, buffsize);
-		err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
-		if (err) {
-			netdev_err(port->dev, "Could not create shared buffer for mirroring\n");
-			return err;
-		}
-	}
-
-	if (bind) {
-		err = mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
-							true);
-		if (err)
-			goto err_port_bind;
-	}
-
-	inspected_port = kzalloc(sizeof(*inspected_port), GFP_KERNEL);
-	if (!inspected_port) {
-		err = -ENOMEM;
-		goto err_inspected_port_alloc;
-	}
-	inspected_port->local_port = port->local_port;
-	inspected_port->type = type;
-	list_add_tail(&inspected_port->list, &span_entry->bound_ports_list);
-
-	return 0;
-
-err_inspected_port_alloc:
-	if (bind)
-		mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
-						  false);
-err_port_bind:
-	if (type == MLXSW_SP_SPAN_EGRESS) {
-		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, 0);
-		mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
-	}
-	return err;
-}
-
-static void
-mlxsw_sp_span_inspected_port_del(struct mlxsw_sp_port *port,
-				 struct mlxsw_sp_span_entry *span_entry,
-				 enum mlxsw_sp_span_type type,
-				 bool bind)
-{
-	struct mlxsw_sp_span_inspected_port *inspected_port;
-	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
-	char sbib_pl[MLXSW_REG_SBIB_LEN];
-
-	inspected_port = mlxsw_sp_span_entry_bound_port_find(port, span_entry);
-	if (!inspected_port)
-		return;
-
-	if (bind)
-		mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
-						  false);
-	/* remove the SBIB buffer if it was egress SPAN */
-	if (type == MLXSW_SP_SPAN_EGRESS) {
-		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, 0);
-		mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
-	}
-
-	mlxsw_sp_span_entry_put(mlxsw_sp, span_entry);
-
-	list_del(&inspected_port->list);
-	kfree(inspected_port);
-}
-
-int mlxsw_sp_span_mirror_add(struct mlxsw_sp_port *from,
-			     struct mlxsw_sp_port *to,
-			     enum mlxsw_sp_span_type type, bool bind)
-{
-	struct mlxsw_sp *mlxsw_sp = from->mlxsw_sp;
-	struct mlxsw_sp_span_entry *span_entry;
-	int err;
-
-	span_entry = mlxsw_sp_span_entry_get(to);
-	if (!span_entry)
-		return -ENOENT;
-
-	netdev_dbg(from->dev, "Adding inspected port to SPAN entry %d\n",
-		   span_entry->id);
-
-	err = mlxsw_sp_span_inspected_port_add(from, span_entry, type, bind);
-	if (err)
-		goto err_port_bind;
-
-	return 0;
-
-err_port_bind:
-	mlxsw_sp_span_entry_put(mlxsw_sp, span_entry);
-	return err;
-}
-
-void mlxsw_sp_span_mirror_del(struct mlxsw_sp_port *from, u8 destination_port,
-			      enum mlxsw_sp_span_type type, bool bind)
-{
-	struct mlxsw_sp_span_entry *span_entry;
-
-	span_entry = mlxsw_sp_span_entry_find(from->mlxsw_sp,
-					      destination_port);
-	if (!span_entry) {
-		netdev_err(from->dev, "no span entry found\n");
-		return;
-	}
-
-	netdev_dbg(from->dev, "removing inspected port from SPAN entry %d\n",
-		   span_entry->id);
-	mlxsw_sp_span_inspected_port_del(from, span_entry, type, bind);
-}
-
 static int mlxsw_sp_port_sample_set(struct mlxsw_sp_port *mlxsw_sp_port,
 				    bool enable, u32 rate)
 {

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -80,6 +80,7 @@ enum mlxsw_sp_resource_id {
 
 struct mlxsw_sp_port;
 struct mlxsw_sp_rif;
+struct mlxsw_sp_span_entry;
 
 struct mlxsw_sp_upper {
 	struct net_device *dev;
@@ -111,25 +112,6 @@ struct mlxsw_sp_mid {
 	unsigned long *ports_in_mid; /* bits array */
 };
 
-enum mlxsw_sp_span_type {
-	MLXSW_SP_SPAN_EGRESS,
-	MLXSW_SP_SPAN_INGRESS
-};
-
-struct mlxsw_sp_span_inspected_port {
-	struct list_head list;
-	enum mlxsw_sp_span_type type;
-	u8 local_port;
-};
-
-struct mlxsw_sp_span_entry {
-	u8 local_port;
-	bool used;
-	struct list_head bound_ports_list;
-	int ref_count;
-	int id;
-};
-
 enum mlxsw_sp_port_mall_action_type {
 	MLXSW_SP_PORT_MALL_MIRROR,
 	MLXSW_SP_PORT_MALL_SAMPLE,
@@ -396,16 +378,6 @@ struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find(struct net_device *dev);
 struct mlxsw_sp_port *mlxsw_sp_port_lower_dev_hold(struct net_device *dev);
 void mlxsw_sp_port_dev_put(struct mlxsw_sp_port *mlxsw_sp_port);
 struct mlxsw_sp_port *mlxsw_sp_port_dev_lower_find_rcu(struct net_device *dev);
-int mlxsw_sp_span_mirror_add(struct mlxsw_sp_port *from,
-			     struct mlxsw_sp_port *to,
-			     enum mlxsw_sp_span_type type,
-			     bool bind);
-void mlxsw_sp_span_mirror_del(struct mlxsw_sp_port *from,
-			      u8 destination_port,
-			      enum mlxsw_sp_span_type type,
-			      bool bind);
-struct mlxsw_sp_span_entry *
-mlxsw_sp_span_entry_find(struct mlxsw_sp *mlxsw_sp, u8 local_port);
 
 /* spectrum_dcb.c */
 #ifdef CONFIG_MLXSW_SPECTRUM_DCB

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_flex_actions.c

@@ -35,6 +35,7 @@
 
 #include "spectrum_acl_flex_actions.h"
 #include "core_acl_flex_actions.h"
+#include "spectrum_span.h"
 
 #define MLXSW_SP_KVDL_ACT_EXT_SIZE 1
 

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/mlxsw_span.c
+ * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/list.h>
+
+#include "spectrum.h"
+#include "spectrum_span.h"
+
+int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp)
+{
+	int i;
+
+	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_SPAN))
+		return -EIO;
+
+	mlxsw_sp->span.entries_count = MLXSW_CORE_RES_GET(mlxsw_sp->core,
+							  MAX_SPAN);
+	mlxsw_sp->span.entries = kcalloc(mlxsw_sp->span.entries_count,
+					 sizeof(struct mlxsw_sp_span_entry),
+					 GFP_KERNEL);
+	if (!mlxsw_sp->span.entries)
+		return -ENOMEM;
+
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++)
+		INIT_LIST_HEAD(&mlxsw_sp->span.entries[i].bound_ports_list);
+
+	return 0;
+}
+
+void mlxsw_sp_span_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	int i;
+
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
+
+		WARN_ON_ONCE(!list_empty(&curr->bound_ports_list));
+	}
+	kfree(mlxsw_sp->span.entries);
+}
+
+static struct mlxsw_sp_span_entry *
+mlxsw_sp_span_entry_create(struct mlxsw_sp_port *port)
+{
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	struct mlxsw_sp_span_entry *span_entry;
+	char mpat_pl[MLXSW_REG_MPAT_LEN];
+	u8 local_port = port->local_port;
+	int index;
+	int i;
+	int err;
+
+	/* find a free entry to use */
+	index = -1;
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		if (!mlxsw_sp->span.entries[i].ref_count) {
+			index = i;
+			span_entry = &mlxsw_sp->span.entries[i];
+			break;
+		}
+	}
+	if (index < 0)
+		return NULL;
+
+	/* create a new port analayzer entry for local_port */
+	mlxsw_reg_mpat_pack(mpat_pl, index, local_port, true);
+	err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpat), mpat_pl);
+	if (err)
+		return NULL;
+
+	span_entry->id = index;
+	span_entry->ref_count = 1;
+	span_entry->local_port = local_port;
+	return span_entry;
+}
+
+static void mlxsw_sp_span_entry_destroy(struct mlxsw_sp *mlxsw_sp,
+					struct mlxsw_sp_span_entry *span_entry)
+{
+	u8 local_port = span_entry->local_port;
+	char mpat_pl[MLXSW_REG_MPAT_LEN];
+	int pa_id = span_entry->id;
+
+	mlxsw_reg_mpat_pack(mpat_pl, pa_id, local_port, false);
+	mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpat), mpat_pl);
+}
+
+struct mlxsw_sp_span_entry *
+mlxsw_sp_span_entry_find(struct mlxsw_sp *mlxsw_sp, u8 local_port)
+{
+	int i;
+
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
+
+		if (curr->ref_count && curr->local_port == local_port)
+			return curr;
+	}
+	return NULL;
+}
+
+static struct mlxsw_sp_span_entry *
+mlxsw_sp_span_entry_get(struct mlxsw_sp_port *port)
+{
+	struct mlxsw_sp_span_entry *span_entry;
+
+	span_entry = mlxsw_sp_span_entry_find(port->mlxsw_sp,
+					      port->local_port);
+	if (span_entry) {
+		/* Already exists, just take a reference */
+		span_entry->ref_count++;
+		return span_entry;
+	}
+
+	return mlxsw_sp_span_entry_create(port);
+}
+
+static int mlxsw_sp_span_entry_put(struct mlxsw_sp *mlxsw_sp,
+				   struct mlxsw_sp_span_entry *span_entry)
+{
+	WARN_ON(!span_entry->ref_count);
+	if (--span_entry->ref_count == 0)
+		mlxsw_sp_span_entry_destroy(mlxsw_sp, span_entry);
+	return 0;
+}
+
+static bool mlxsw_sp_span_is_egress_mirror(struct mlxsw_sp_port *port)
+{
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	struct mlxsw_sp_span_inspected_port *p;
+	int i;
+
+	for (i = 0; i < mlxsw_sp->span.entries_count; i++) {
+		struct mlxsw_sp_span_entry *curr = &mlxsw_sp->span.entries[i];
+
+		list_for_each_entry(p, &curr->bound_ports_list, list)
+			if (p->local_port == port->local_port &&
+			    p->type == MLXSW_SP_SPAN_EGRESS)
+				return true;
+	}
+
+	return false;
+}
+
+static int mlxsw_sp_span_mtu_to_buffsize(const struct mlxsw_sp *mlxsw_sp,
+					 int mtu)
+{
+	return mlxsw_sp_bytes_cells(mlxsw_sp, mtu * 5 / 2) + 1;
+}
+
+int mlxsw_sp_span_port_mtu_update(struct mlxsw_sp_port *port, u16 mtu)
+{
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	char sbib_pl[MLXSW_REG_SBIB_LEN];
+	int err;
+
+	/* If port is egress mirrored, the shared buffer size should be
+	 * updated according to the mtu value
+	 */
+	if (mlxsw_sp_span_is_egress_mirror(port)) {
+		u32 buffsize = mlxsw_sp_span_mtu_to_buffsize(mlxsw_sp, mtu);
+
+		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, buffsize);
+		err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
+		if (err) {
+			netdev_err(port->dev, "Could not update shared buffer for mirroring\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static struct mlxsw_sp_span_inspected_port *
+mlxsw_sp_span_entry_bound_port_find(struct mlxsw_sp_port *port,
+				    struct mlxsw_sp_span_entry *span_entry)
+{
+	struct mlxsw_sp_span_inspected_port *p;
+
+	list_for_each_entry(p, &span_entry->bound_ports_list, list)
+		if (port->local_port == p->local_port)
+			return p;
+	return NULL;
+}
+
+static int
+mlxsw_sp_span_inspected_port_bind(struct mlxsw_sp_port *port,
+				  struct mlxsw_sp_span_entry *span_entry,
+				  enum mlxsw_sp_span_type type,
+				  bool bind)
+{
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	char mpar_pl[MLXSW_REG_MPAR_LEN];
+	int pa_id = span_entry->id;
+
+	/* bind the port to the SPAN entry */
+	mlxsw_reg_mpar_pack(mpar_pl, port->local_port,
+			    (enum mlxsw_reg_mpar_i_e)type, bind, pa_id);
+	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpar), mpar_pl);
+}
+
+static int
+mlxsw_sp_span_inspected_port_add(struct mlxsw_sp_port *port,
+				 struct mlxsw_sp_span_entry *span_entry,
+				 enum mlxsw_sp_span_type type,
+				 bool bind)
+{
+	struct mlxsw_sp_span_inspected_port *inspected_port;
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	char sbib_pl[MLXSW_REG_SBIB_LEN];
+	int err;
+
+	/* if it is an egress SPAN, bind a shared buffer to it */
+	if (type == MLXSW_SP_SPAN_EGRESS) {
+		u32 buffsize = mlxsw_sp_span_mtu_to_buffsize(mlxsw_sp,
+							     port->dev->mtu);
+
+		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, buffsize);
+		err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
+		if (err) {
+			netdev_err(port->dev, "Could not create shared buffer for mirroring\n");
+			return err;
+		}
+	}
+
+	if (bind) {
+		err = mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
+							true);
+		if (err)
+			goto err_port_bind;
+	}
+
+	inspected_port = kzalloc(sizeof(*inspected_port), GFP_KERNEL);
+	if (!inspected_port) {
+		err = -ENOMEM;
+		goto err_inspected_port_alloc;
+	}
+	inspected_port->local_port = port->local_port;
+	inspected_port->type = type;
+	list_add_tail(&inspected_port->list, &span_entry->bound_ports_list);
+
+	return 0;
+
+err_inspected_port_alloc:
+	if (bind)
+		mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
+						  false);
+err_port_bind:
+	if (type == MLXSW_SP_SPAN_EGRESS) {
+		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, 0);
+		mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
+	}
+	return err;
+}
+
+static void
+mlxsw_sp_span_inspected_port_del(struct mlxsw_sp_port *port,
+				 struct mlxsw_sp_span_entry *span_entry,
+				 enum mlxsw_sp_span_type type,
+				 bool bind)
+{
+	struct mlxsw_sp_span_inspected_port *inspected_port;
+	struct mlxsw_sp *mlxsw_sp = port->mlxsw_sp;
+	char sbib_pl[MLXSW_REG_SBIB_LEN];
+
+	inspected_port = mlxsw_sp_span_entry_bound_port_find(port, span_entry);
+	if (!inspected_port)
+		return;
+
+	if (bind)
+		mlxsw_sp_span_inspected_port_bind(port, span_entry, type,
+						  false);
+	/* remove the SBIB buffer if it was egress SPAN */
+	if (type == MLXSW_SP_SPAN_EGRESS) {
+		mlxsw_reg_sbib_pack(sbib_pl, port->local_port, 0);
+		mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
+	}
+
+	mlxsw_sp_span_entry_put(mlxsw_sp, span_entry);
+
+	list_del(&inspected_port->list);
+	kfree(inspected_port);
+}
+
+int mlxsw_sp_span_mirror_add(struct mlxsw_sp_port *from,
+			     struct mlxsw_sp_port *to,
+			     enum mlxsw_sp_span_type type, bool bind)
+{
+	struct mlxsw_sp *mlxsw_sp = from->mlxsw_sp;
+	struct mlxsw_sp_span_entry *span_entry;
+	int err;
+
+	span_entry = mlxsw_sp_span_entry_get(to);
+	if (!span_entry)
+		return -ENOENT;
+
+	netdev_dbg(from->dev, "Adding inspected port to SPAN entry %d\n",
+		   span_entry->id);
+
+	err = mlxsw_sp_span_inspected_port_add(from, span_entry, type, bind);
+	if (err)
+		goto err_port_bind;
+
+	return 0;
+
+err_port_bind:
+	mlxsw_sp_span_entry_put(mlxsw_sp, span_entry);
+	return err;
+}
+
+void mlxsw_sp_span_mirror_del(struct mlxsw_sp_port *from, u8 destination_port,
+			      enum mlxsw_sp_span_type type, bool bind)
+{
+	struct mlxsw_sp_span_entry *span_entry;
+
+	span_entry = mlxsw_sp_span_entry_find(from->mlxsw_sp,
+					      destination_port);
+	if (!span_entry) {
+		netdev_err(from->dev, "no span entry found\n");
+		return;
+	}
+
+	netdev_dbg(from->dev, "removing inspected port from SPAN entry %d\n",
+		   span_entry->id);
+	mlxsw_sp_span_inspected_port_del(from, span_entry, type, bind);
+}

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.h

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/mlxsw_span.h
+ * Copyright (c) 2018 Mellanox Technologies. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MLXSW_SPECTRUM_SPAN_H
+#define _MLXSW_SPECTRUM_SPAN_H
+
+#include <linux/types.h>
+
+struct mlxsw_sp;
+struct mlxsw_sp_port;
+
+enum mlxsw_sp_span_type {
+	MLXSW_SP_SPAN_EGRESS,
+	MLXSW_SP_SPAN_INGRESS
+};
+
+struct mlxsw_sp_span_inspected_port {
+	struct list_head list;
+	enum mlxsw_sp_span_type type;
+	u8 local_port;
+};
+
+struct mlxsw_sp_span_entry {
+	u8 local_port;
+	struct list_head bound_ports_list;
+	int ref_count;
+	int id;
+};
+
+int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp);
+void mlxsw_sp_span_fini(struct mlxsw_sp *mlxsw_sp);
+
+int mlxsw_sp_span_mirror_add(struct mlxsw_sp_port *from,
+			     struct mlxsw_sp_port *to,
+			     enum mlxsw_sp_span_type type, bool bind);
+void mlxsw_sp_span_mirror_del(struct mlxsw_sp_port *from, u8 destination_port,
+			      enum mlxsw_sp_span_type type, bool bind);
+struct mlxsw_sp_span_entry *
+mlxsw_sp_span_entry_find(struct mlxsw_sp *mlxsw_sp, u8 local_port);
+
+int mlxsw_sp_span_port_mtu_update(struct mlxsw_sp_port *port, u16 mtu);
+
+#endif