mlxsw: core: Introduce flexible keys support

Hardware supports matching on so called "flexible keys". The idea is to
assemble an optimal key to use for matching according to the fields in
packet (elements) requested by user. Certain sets of elements are
combined into pre-defined blocks. There is a picker to find needed blocks.
Keys consist of 1..n blocks.

Alongside with that, an initial portion of elements is introduced in order
to be able to offload basic cls_flower rules.

Picked keys are cached so multiple rules could share them.

There is an encode function provided that takes care of encoding key and
mask values according to given key.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Makefile

 obj-$(CONFIG_MLXSW_CORE)	+= mlxsw_core.o
-mlxsw_core-objs			:= core.o
+mlxsw_core-objs			:= core.o core_acl_flex_keys.o
 mlxsw_core-$(CONFIG_MLXSW_CORE_HWMON) += core_hwmon.o
 mlxsw_core-$(CONFIG_MLXSW_CORE_THERMAL) += core_thermal.o
 obj-$(CONFIG_MLXSW_PCI)		+= mlxsw_pci.o

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

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.h
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Jiri Pirko <jiri@mellanox.com>
+ *
+ * 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_CORE_ACL_FLEX_KEYS_H
+#define _MLXSW_CORE_ACL_FLEX_KEYS_H
+
+#include <linux/types.h>
+#include <linux/bitmap.h>
+
+#include "item.h"
+
+enum mlxsw_afk_element {
+	MLXSW_AFK_ELEMENT_SRC_SYS_PORT,
+	MLXSW_AFK_ELEMENT_DMAC,
+	MLXSW_AFK_ELEMENT_SMAC,
+	MLXSW_AFK_ELEMENT_ETHERTYPE,
+	MLXSW_AFK_ELEMENT_IP_PROTO,
+	MLXSW_AFK_ELEMENT_SRC_IP4,
+	MLXSW_AFK_ELEMENT_DST_IP4,
+	MLXSW_AFK_ELEMENT_SRC_IP6_HI,
+	MLXSW_AFK_ELEMENT_SRC_IP6_LO,
+	MLXSW_AFK_ELEMENT_DST_IP6_HI,
+	MLXSW_AFK_ELEMENT_DST_IP6_LO,
+	MLXSW_AFK_ELEMENT_DST_L4_PORT,
+	MLXSW_AFK_ELEMENT_SRC_L4_PORT,
+	MLXSW_AFK_ELEMENT_MAX,
+};
+
+enum mlxsw_afk_element_type {
+	MLXSW_AFK_ELEMENT_TYPE_U32,
+	MLXSW_AFK_ELEMENT_TYPE_BUF,
+};
+
+struct mlxsw_afk_element_info {
+	enum mlxsw_afk_element element; /* element ID */
+	enum mlxsw_afk_element_type type;
+	struct mlxsw_item item; /* element geometry in internal storage */
+};
+
+#define MLXSW_AFK_ELEMENT_INFO(_type, _element, _offset, _shift, _size)		\
+	[MLXSW_AFK_ELEMENT_##_element] = {					\
+		.element = MLXSW_AFK_ELEMENT_##_element,			\
+		.type = _type,							\
+		.item = {							\
+			.offset = _offset,					\
+			.shift = _shift,					\
+			.size = {.bits = _size},				\
+			.name = #_element,					\
+		},								\
+	}
+
+#define MLXSW_AFK_ELEMENT_INFO_U32(_element, _offset, _shift, _size)		\
+	MLXSW_AFK_ELEMENT_INFO(MLXSW_AFK_ELEMENT_TYPE_U32,			\
+			       _element, _offset, _shift, _size)
+
+#define MLXSW_AFK_ELEMENT_INFO_BUF(_element, _offset, _size)			\
+	MLXSW_AFK_ELEMENT_INFO(MLXSW_AFK_ELEMENT_TYPE_BUF,			\
+			       _element, _offset, 0, _size)
+
+/* For the purpose of the driver, define a internal storage scratchpad
+ * that will be used to store key/mask values. For each defined element type
+ * define an internal storage geometry.
+ */
+static const struct mlxsw_afk_element_info mlxsw_afk_element_infos[] = {
+	MLXSW_AFK_ELEMENT_INFO_U32(SRC_SYS_PORT, 0x00, 16, 16),
+	MLXSW_AFK_ELEMENT_INFO_BUF(DMAC, 0x04, 6),
+	MLXSW_AFK_ELEMENT_INFO_BUF(SMAC, 0x0A, 6),
+	MLXSW_AFK_ELEMENT_INFO_U32(ETHERTYPE, 0x00, 0, 16),
+	MLXSW_AFK_ELEMENT_INFO_U32(IP_PROTO, 0x10, 0, 8),
+	MLXSW_AFK_ELEMENT_INFO_U32(SRC_IP4, 0x18, 0, 32),
+	MLXSW_AFK_ELEMENT_INFO_U32(DST_IP4, 0x1C, 0, 32),
+	MLXSW_AFK_ELEMENT_INFO_BUF(SRC_IP6_HI, 0x18, 8),
+	MLXSW_AFK_ELEMENT_INFO_BUF(SRC_IP6_LO, 0x20, 8),
+	MLXSW_AFK_ELEMENT_INFO_BUF(DST_IP6_HI, 0x28, 8),
+	MLXSW_AFK_ELEMENT_INFO_BUF(DST_IP6_LO, 0x30, 8),
+	MLXSW_AFK_ELEMENT_INFO_U32(DST_L4_PORT, 0x14, 0, 16),
+	MLXSW_AFK_ELEMENT_INFO_U32(SRC_L4_PORT, 0x14, 16, 16),
+};
+
+#define MLXSW_AFK_ELEMENT_STORAGE_SIZE 0x38
+
+struct mlxsw_afk_element_inst { /* element instance in actual block */
+	const struct mlxsw_afk_element_info *info;
+	enum mlxsw_afk_element_type type;
+	struct mlxsw_item item; /* element geometry in block */
+};
+
+#define MLXSW_AFK_ELEMENT_INST(_type, _element, _offset, _shift, _size)		\
+	{									\
+		.info = &mlxsw_afk_element_infos[MLXSW_AFK_ELEMENT_##_element],	\
+		.type = _type,							\
+		.item = {							\
+			.offset = _offset,					\
+			.shift = _shift,					\
+			.size = {.bits = _size},				\
+			.name = #_element,					\
+		},								\
+	}
+
+#define MLXSW_AFK_ELEMENT_INST_U32(_element, _offset, _shift, _size)		\
+	MLXSW_AFK_ELEMENT_INST(MLXSW_AFK_ELEMENT_TYPE_U32,			\
+			       _element, _offset, _shift, _size)
+
+#define MLXSW_AFK_ELEMENT_INST_BUF(_element, _offset, _size)			\
+	MLXSW_AFK_ELEMENT_INST(MLXSW_AFK_ELEMENT_TYPE_BUF,			\
+			       _element, _offset, 0, _size)
+
+struct mlxsw_afk_block {
+	u16 encoding; /* block ID */
+	struct mlxsw_afk_element_inst *instances;
+	unsigned int instances_count;
+};
+
+#define MLXSW_AFK_BLOCK(_encoding, _instances)					\
+	{									\
+		.encoding = _encoding,						\
+		.instances = _instances,					\
+		.instances_count = ARRAY_SIZE(_instances),			\
+	}
+
+struct mlxsw_afk_element_usage {
+	DECLARE_BITMAP(usage, MLXSW_AFK_ELEMENT_MAX);
+};
+
+#define mlxsw_afk_element_usage_for_each(element, elusage)			\
+	for_each_set_bit(element, (elusage)->usage, MLXSW_AFK_ELEMENT_MAX)
+
+static inline void
+mlxsw_afk_element_usage_add(struct mlxsw_afk_element_usage *elusage,
+			    enum mlxsw_afk_element element)
+{
+	__set_bit(element, elusage->usage);
+}
+
+static inline void
+mlxsw_afk_element_usage_zero(struct mlxsw_afk_element_usage *elusage)
+{
+	bitmap_zero(elusage->usage, MLXSW_AFK_ELEMENT_MAX);
+}
+
+static inline void
+mlxsw_afk_element_usage_fill(struct mlxsw_afk_element_usage *elusage,
+			     const enum mlxsw_afk_element *elements,
+			     unsigned int elements_count)
+{
+	int i;
+
+	mlxsw_afk_element_usage_zero(elusage);
+	for (i = 0; i < elements_count; i++)
+		mlxsw_afk_element_usage_add(elusage, elements[i]);
+}
+
+static inline bool
+mlxsw_afk_element_usage_subset(struct mlxsw_afk_element_usage *elusage_small,
+			       struct mlxsw_afk_element_usage *elusage_big)
+{
+	int i;
+
+	for (i = 0; i < MLXSW_AFK_ELEMENT_MAX; i++)
+		if (test_bit(i, elusage_small->usage) &&
+		    !test_bit(i, elusage_big->usage))
+			return false;
+	return true;
+}
+
+struct mlxsw_afk;
+
+struct mlxsw_afk *mlxsw_afk_create(unsigned int max_blocks,
+				   const struct mlxsw_afk_block *blocks,
+				   unsigned int blocks_count);
+void mlxsw_afk_destroy(struct mlxsw_afk *mlxsw_afk);
+
+struct mlxsw_afk_key_info;
+
+struct mlxsw_afk_key_info *
+mlxsw_afk_key_info_get(struct mlxsw_afk *mlxsw_afk,
+		       struct mlxsw_afk_element_usage *elusage);
+void mlxsw_afk_key_info_put(struct mlxsw_afk_key_info *key_info);
+bool mlxsw_afk_key_info_subset(struct mlxsw_afk_key_info *key_info,
+			       struct mlxsw_afk_element_usage *elusage);
+
+u16
+mlxsw_afk_key_info_block_encoding_get(const struct mlxsw_afk_key_info *key_info,
+				      int block_index);
+unsigned int
+mlxsw_afk_key_info_blocks_count_get(const struct mlxsw_afk_key_info *key_info);
+
+struct mlxsw_afk_element_values {
+	struct mlxsw_afk_element_usage elusage;
+	struct {
+		char key[MLXSW_AFK_ELEMENT_STORAGE_SIZE];
+		char mask[MLXSW_AFK_ELEMENT_STORAGE_SIZE];
+	} storage;
+};
+
+void mlxsw_afk_values_add_u32(struct mlxsw_afk_element_values *values,
+			      enum mlxsw_afk_element element,
+			      u32 key_value, u32 mask_value);
+void mlxsw_afk_values_add_buf(struct mlxsw_afk_element_values *values,
+			      enum mlxsw_afk_element element,
+			      const char *key_value, const char *mask_value,
+			      unsigned int len);
+void mlxsw_afk_encode(struct mlxsw_afk_key_info *key_info,
+		      struct mlxsw_afk_element_values *values,
+		      char *key, char *mask);
+
+#endif