can: introduce CAN midlayer private and allocate it automatically

This patch introduces the CAN midlayer private structure ("struct
can_ml_priv") which should be used to hold protocol specific per device
data structures. For now it's only member is "struct can_dev_rcv_lists".

The CAN midlayer private is allocated via alloc_netdev()'s private and
assigned to "struct net_device::ml_priv" during device creation. This is
done transparently for CAN drivers using alloc_candev(). The slcan, vcan
and vxcan drivers which are not using alloc_candev() have been adopted
manually. The memory layout of the netdev_priv allocated via
alloc_candev() will looke like this:

  +-------------------------+
  | driver's priv           |
  +-------------------------+
  | struct can_ml_priv      |
  +-------------------------+
  | array of struct sk_buff |
  +-------------------------+

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 66 insertions, 0 deletions

diff --git a/include/linux/can/can-ml.h b/include/linux/can/can-ml.h
new file mode 100644
index 000000000000..0a9d778de8af
--- /dev/null
+++ b/include/linux/can/can-ml.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * Copyright (c) 2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ *
+ * 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 name of Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * 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 CAN_ML_H
+#define CAN_ML_H
+
+#include <linux/can.h>
+#include <linux/list.h>
+
+#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
+#define CAN_EFF_RCV_HASH_BITS 10
+#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)
+
+enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX };
+
+struct can_dev_rcv_lists {
+	struct hlist_head rx[RX_MAX];
+	struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ];
+	struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ];
+	int remove_on_zero_entries;
+	int entries;
+};
+
+struct can_ml_priv {
+	struct can_dev_rcv_lists dev_rcv_lists;
+};
+
+#endif /* CAN_ML_H */