mlxsw: spectrum: Add support for counter allocator

Add implementation for counter allocator. The ASIC has special memory
pool for various counting purposes. Counter memory is distributed between
equal size banks.

The static sub-pool configuration should specify the following parameters
for each sub-pool:
- Number of required banks.
- Maximum entry size.

Each module can add dedicated sub-pool or use existing one.

Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 177 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
new file mode 100644
index 000000000000..0cae75c415d4
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
@@ -0,0 +1,177 @@
+/*
+ * drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Arkadi Sharshevsky <arkadis@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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+
+#include "spectrum_cnt.h"
+
+#define MLXSW_SP_COUNTER_POOL_BANK_SIZE 4096
+
+struct mlxsw_sp_counter_sub_pool {
+	unsigned int base_index;
+	unsigned int size;
+	unsigned int entry_size;
+	unsigned int bank_count;
+};
+
+struct mlxsw_sp_counter_pool {
+	unsigned int pool_size;
+	unsigned long *usage; /* Usage bitmap */
+	struct mlxsw_sp_counter_sub_pool *sub_pools;
+};
+
+static struct mlxsw_sp_counter_sub_pool mlxsw_sp_counter_sub_pools[] = {};
+
+static int mlxsw_sp_counter_pool_validate(struct mlxsw_sp *mlxsw_sp)
+{
+	unsigned int total_bank_config = 0;
+	unsigned int pool_size;
+	int i;
+
+	pool_size = MLXSW_CORE_RES_GET(mlxsw_sp->core, COUNTER_POOL_SIZE);
+	/* Check config is valid, no bank over subscription */
+	for (i = 0; i < ARRAY_SIZE(mlxsw_sp_counter_sub_pools); i++)
+		total_bank_config += mlxsw_sp_counter_sub_pools[i].bank_count;
+	if (total_bank_config > pool_size / MLXSW_SP_COUNTER_POOL_BANK_SIZE + 1)
+		return -EINVAL;
+	return 0;
+}
+
+int mlxsw_sp_counter_pool_init(struct mlxsw_sp *mlxsw_sp)
+{
+	struct mlxsw_sp_counter_sub_pool *sub_pool;
+	struct mlxsw_sp_counter_pool *pool;
+	unsigned int base_index;
+	unsigned int map_size;
+	int i;
+	int err;
+
+	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, COUNTER_POOL_SIZE))
+		return -EIO;
+
+	err = mlxsw_sp_counter_pool_validate(mlxsw_sp);
+	if (err)
+		return err;
+
+	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool)
+		return -ENOMEM;
+
+	pool->pool_size = MLXSW_CORE_RES_GET(mlxsw_sp->core, COUNTER_POOL_SIZE);
+	map_size = BITS_TO_LONGS(pool->pool_size) * sizeof(unsigned long);
+
+	pool->usage = kzalloc(map_size, GFP_KERNEL);
+	if (!pool->usage) {
+		err = -ENOMEM;
+		goto err_usage_alloc;
+	}
+
+	pool->sub_pools = mlxsw_sp_counter_sub_pools;
+	/* Allocation is based on bank count which should be
+	 * specified for each sub pool statically.
+	 */
+	base_index = 0;
+	for (i = 0; i < ARRAY_SIZE(mlxsw_sp_counter_sub_pools); i++) {
+		sub_pool = &pool->sub_pools[i];
+		sub_pool->size = sub_pool->bank_count *
+				 MLXSW_SP_COUNTER_POOL_BANK_SIZE;
+		sub_pool->base_index = base_index;
+		base_index += sub_pool->size;
+		/* The last bank can't be fully used */
+		if (sub_pool->base_index + sub_pool->size > pool->pool_size)
+			sub_pool->size = pool->pool_size - sub_pool->base_index;
+	}
+
+	mlxsw_sp->counter_pool = pool;
+	return 0;
+
+err_usage_alloc:
+	kfree(pool);
+	return err;
+}
+
+void mlxsw_sp_counter_pool_fini(struct mlxsw_sp *mlxsw_sp)
+{
+	struct mlxsw_sp_counter_pool *pool = mlxsw_sp->counter_pool;
+
+	WARN_ON(find_first_bit(pool->usage, pool->pool_size) !=
+			       pool->pool_size);
+	kfree(pool->usage);
+	kfree(pool);
+}
+
+int mlxsw_sp_counter_alloc(struct mlxsw_sp *mlxsw_sp,
+			   enum mlxsw_sp_counter_sub_pool_id sub_pool_id,
+			   unsigned int *p_counter_index)
+{
+	struct mlxsw_sp_counter_pool *pool = mlxsw_sp->counter_pool;
+	struct mlxsw_sp_counter_sub_pool *sub_pool;
+	unsigned int entry_index;
+	unsigned int stop_index;
+	int i;
+
+	sub_pool = &mlxsw_sp_counter_sub_pools[sub_pool_id];
+	stop_index = sub_pool->base_index + sub_pool->size;
+	entry_index = sub_pool->base_index;
+
+	entry_index = find_next_zero_bit(pool->usage, stop_index, entry_index);
+	if (entry_index == stop_index)
+		return -ENOBUFS;
+	/* The sub-pools can contain non-integer number of entries
+	 * so we must check for overflow
+	 */
+	if (entry_index + sub_pool->entry_size > stop_index)
+		return -ENOBUFS;
+	for (i = 0; i < sub_pool->entry_size; i++)
+		__set_bit(entry_index + i, pool->usage);
+
+	*p_counter_index = entry_index;
+	return 0;
+}
+
+void mlxsw_sp_counter_free(struct mlxsw_sp *mlxsw_sp,
+			   enum mlxsw_sp_counter_sub_pool_id sub_pool_id,
+			   unsigned int counter_index)
+{
+	struct mlxsw_sp_counter_pool *pool = mlxsw_sp->counter_pool;
+	struct mlxsw_sp_counter_sub_pool *sub_pool;
+	int i;
+
+	if (WARN_ON(counter_index >= pool->pool_size))
+		return;
+	sub_pool = &mlxsw_sp_counter_sub_pools[sub_pool_id];
+	for (i = 0; i < sub_pool->entry_size; i++)
+		__clear_bit(counter_index + i, pool->usage);
+}