1 /*
2  * drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c
3  * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
4  * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the names of the copyright holders nor the names of its
15  *    contributors may be used to endorse or promote products derived from
16  *    this software without specific prior written permission.
17  *
18  * Alternatively, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2 as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/bitops.h>
37 
38 #include "spectrum.h"
39 
40 #define MLXSW_SP_KVDL_SINGLE_BASE 0
41 #define MLXSW_SP_KVDL_SINGLE_SIZE 16384
42 #define MLXSW_SP_KVDL_CHUNKS_BASE \
43 	(MLXSW_SP_KVDL_SINGLE_BASE + MLXSW_SP_KVDL_SINGLE_SIZE)
44 #define MLXSW_SP_KVDL_CHUNKS_SIZE \
45 	(MLXSW_SP_KVD_LINEAR_SIZE - MLXSW_SP_KVDL_CHUNKS_BASE)
46 #define MLXSW_SP_CHUNK_MAX 32
47 
48 int mlxsw_sp_kvdl_alloc(struct mlxsw_sp *mlxsw_sp, unsigned int entry_count)
49 {
50 	int entry_index;
51 	int size;
52 	int type_base;
53 	int type_size;
54 	int type_entries;
55 
56 	if (entry_count == 0 || entry_count > MLXSW_SP_CHUNK_MAX) {
57 		return -EINVAL;
58 	} else if (entry_count == 1) {
59 		type_base = MLXSW_SP_KVDL_SINGLE_BASE;
60 		type_size = MLXSW_SP_KVDL_SINGLE_SIZE;
61 		type_entries = 1;
62 	} else {
63 		type_base = MLXSW_SP_KVDL_CHUNKS_BASE;
64 		type_size = MLXSW_SP_KVDL_CHUNKS_SIZE;
65 		type_entries = MLXSW_SP_CHUNK_MAX;
66 	}
67 
68 	entry_index = type_base;
69 	size = type_base + type_size;
70 	for_each_clear_bit_from(entry_index, mlxsw_sp->kvdl.usage, size) {
71 		int i;
72 
73 		for (i = 0; i < type_entries; i++)
74 			set_bit(entry_index + i, mlxsw_sp->kvdl.usage);
75 		return entry_index;
76 	}
77 	return -ENOBUFS;
78 }
79 
80 void mlxsw_sp_kvdl_free(struct mlxsw_sp *mlxsw_sp, int entry_index)
81 {
82 	int type_entries;
83 	int i;
84 
85 	if (entry_index < MLXSW_SP_KVDL_CHUNKS_BASE)
86 		type_entries = 1;
87 	else
88 		type_entries = MLXSW_SP_CHUNK_MAX;
89 	for (i = 0; i < type_entries; i++)
90 		clear_bit(entry_index + i, mlxsw_sp->kvdl.usage);
91 }
92