mlxsw: spectrum: Move SPAN code to separate module

For the upcoming work on SPAN, it makes sense to move the current code
to a module of its own. It already has a well-defined API boundary to
the mirror management (which is used from matchall and ACL code). A
couple more functions need to be exported for the functions that
spectrum.c needs to use for MTU handling and subsystem init/fini.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 356 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
new file mode 100644
index 000000000000..c3bec37d71ed
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
@@ -0,0 +1,356 @@
+/*
+ * 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);
+}