xref: /openbmc/linux/drivers/net/ethernet/mellanox/mlxsw/spectrum_kvdl.c (revision 45cc842d5b75ba8f9a958f2dd12b95c6dd0452bd)
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_SINGLE_END \
43 	(MLXSW_SP_KVDL_SINGLE_SIZE + MLXSW_SP_KVDL_SINGLE_BASE - 1)
44 
45 #define MLXSW_SP_KVDL_CHUNKS_BASE \
46 	(MLXSW_SP_KVDL_SINGLE_BASE + MLXSW_SP_KVDL_SINGLE_SIZE)
47 #define MLXSW_SP_KVDL_CHUNKS_SIZE 49152
48 #define MLXSW_SP_KVDL_CHUNKS_END \
49 	(MLXSW_SP_KVDL_CHUNKS_SIZE + MLXSW_SP_KVDL_CHUNKS_BASE - 1)
50 
51 #define MLXSW_SP_KVDL_LARGE_CHUNKS_BASE \
52 	(MLXSW_SP_KVDL_CHUNKS_BASE + MLXSW_SP_KVDL_CHUNKS_SIZE)
53 #define MLXSW_SP_KVDL_LARGE_CHUNKS_SIZE \
54 	(MLXSW_SP_KVD_LINEAR_SIZE - MLXSW_SP_KVDL_LARGE_CHUNKS_BASE)
55 #define MLXSW_SP_KVDL_LARGE_CHUNKS_END \
56 	(MLXSW_SP_KVDL_LARGE_CHUNKS_SIZE + MLXSW_SP_KVDL_LARGE_CHUNKS_BASE - 1)
57 
58 #define MLXSW_SP_CHUNK_MAX 32
59 #define MLXSW_SP_LARGE_CHUNK_MAX 512
60 
61 struct mlxsw_sp_kvdl_part_info {
62 	unsigned int part_index;
63 	unsigned int start_index;
64 	unsigned int end_index;
65 	unsigned int alloc_size;
66 };
67 
68 struct mlxsw_sp_kvdl_part {
69 	struct list_head list;
70 	const struct mlxsw_sp_kvdl_part_info *info;
71 	unsigned long usage[0];	/* Entries */
72 };
73 
74 struct mlxsw_sp_kvdl {
75 	struct list_head parts_list;
76 };
77 
78 static struct mlxsw_sp_kvdl_part *
79 mlxsw_sp_kvdl_alloc_size_part(struct mlxsw_sp_kvdl *kvdl,
80 			      unsigned int alloc_size)
81 {
82 	struct mlxsw_sp_kvdl_part *part, *min_part = NULL;
83 
84 	list_for_each_entry(part, &kvdl->parts_list, list) {
85 		if (alloc_size <= part->info->alloc_size &&
86 		    (!min_part ||
87 		     part->info->alloc_size <= min_part->info->alloc_size))
88 			min_part = part;
89 	}
90 
91 	return min_part ?: ERR_PTR(-ENOBUFS);
92 }
93 
94 static struct mlxsw_sp_kvdl_part *
95 mlxsw_sp_kvdl_index_part(struct mlxsw_sp_kvdl *kvdl, u32 kvdl_index)
96 {
97 	struct mlxsw_sp_kvdl_part *part;
98 
99 	list_for_each_entry(part, &kvdl->parts_list, list) {
100 		if (kvdl_index >= part->info->start_index &&
101 		    kvdl_index <= part->info->end_index)
102 			return part;
103 	}
104 
105 	return ERR_PTR(-EINVAL);
106 }
107 
108 static u32
109 mlxsw_sp_entry_index_kvdl_index(const struct mlxsw_sp_kvdl_part_info *info,
110 				unsigned int entry_index)
111 {
112 	return info->start_index + entry_index * info->alloc_size;
113 }
114 
115 static unsigned int
116 mlxsw_sp_kvdl_index_entry_index(const struct mlxsw_sp_kvdl_part_info *info,
117 				u32 kvdl_index)
118 {
119 	return (kvdl_index - info->start_index) / info->alloc_size;
120 }
121 
122 static int mlxsw_sp_kvdl_part_alloc(struct mlxsw_sp_kvdl_part *part,
123 				    u32 *p_kvdl_index)
124 {
125 	const struct mlxsw_sp_kvdl_part_info *info = part->info;
126 	unsigned int entry_index, nr_entries;
127 
128 	nr_entries = (info->end_index - info->start_index + 1) /
129 		     info->alloc_size;
130 	entry_index = find_first_zero_bit(part->usage, nr_entries);
131 	if (entry_index == nr_entries)
132 		return -ENOBUFS;
133 	__set_bit(entry_index, part->usage);
134 
135 	*p_kvdl_index = mlxsw_sp_entry_index_kvdl_index(part->info,
136 							entry_index);
137 
138 	return 0;
139 }
140 
141 static void mlxsw_sp_kvdl_part_free(struct mlxsw_sp_kvdl_part *part,
142 				    u32 kvdl_index)
143 {
144 	unsigned int entry_index;
145 
146 	entry_index = mlxsw_sp_kvdl_index_entry_index(part->info,
147 						      kvdl_index);
148 	__clear_bit(entry_index, part->usage);
149 }
150 
151 int mlxsw_sp_kvdl_alloc(struct mlxsw_sp *mlxsw_sp, unsigned int entry_count,
152 			u32 *p_entry_index)
153 {
154 	struct mlxsw_sp_kvdl_part *part;
155 
156 	/* Find partition with smallest allocation size satisfying the
157 	 * requested size.
158 	 */
159 	part = mlxsw_sp_kvdl_alloc_size_part(mlxsw_sp->kvdl, entry_count);
160 	if (IS_ERR(part))
161 		return PTR_ERR(part);
162 
163 	return mlxsw_sp_kvdl_part_alloc(part, p_entry_index);
164 }
165 
166 void mlxsw_sp_kvdl_free(struct mlxsw_sp *mlxsw_sp, int entry_index)
167 {
168 	struct mlxsw_sp_kvdl_part *part;
169 
170 	part = mlxsw_sp_kvdl_index_part(mlxsw_sp->kvdl, entry_index);
171 	if (IS_ERR(part))
172 		return;
173 	mlxsw_sp_kvdl_part_free(part, entry_index);
174 }
175 
176 int mlxsw_sp_kvdl_alloc_size_query(struct mlxsw_sp *mlxsw_sp,
177 				   unsigned int entry_count,
178 				   unsigned int *p_alloc_size)
179 {
180 	struct mlxsw_sp_kvdl_part *part;
181 
182 	part = mlxsw_sp_kvdl_alloc_size_part(mlxsw_sp->kvdl, entry_count);
183 	if (IS_ERR(part))
184 		return PTR_ERR(part);
185 
186 	*p_alloc_size = part->info->alloc_size;
187 
188 	return 0;
189 }
190 
191 static const struct mlxsw_sp_kvdl_part_info kvdl_parts_info[] = {
192 	{
193 		.part_index	= 0,
194 		.start_index	= MLXSW_SP_KVDL_SINGLE_BASE,
195 		.end_index	= MLXSW_SP_KVDL_SINGLE_END,
196 		.alloc_size	= 1,
197 	},
198 	{
199 		.part_index	= 1,
200 		.start_index	= MLXSW_SP_KVDL_CHUNKS_BASE,
201 		.end_index	= MLXSW_SP_KVDL_CHUNKS_END,
202 		.alloc_size	= MLXSW_SP_CHUNK_MAX,
203 	},
204 	{
205 		.part_index	= 2,
206 		.start_index	= MLXSW_SP_KVDL_LARGE_CHUNKS_BASE,
207 		.end_index	= MLXSW_SP_KVDL_LARGE_CHUNKS_END,
208 		.alloc_size	= MLXSW_SP_LARGE_CHUNK_MAX,
209 	},
210 };
211 
212 static struct mlxsw_sp_kvdl_part *
213 mlxsw_sp_kvdl_part_find(struct mlxsw_sp *mlxsw_sp, unsigned int part_index)
214 {
215 	struct mlxsw_sp_kvdl_part *part;
216 
217 	list_for_each_entry(part, &mlxsw_sp->kvdl->parts_list, list) {
218 		if (part->info->part_index == part_index)
219 			return part;
220 	}
221 
222 	return NULL;
223 }
224 
225 static int mlxsw_sp_kvdl_part_init(struct mlxsw_sp *mlxsw_sp,
226 				   unsigned int part_index)
227 {
228 	const struct mlxsw_sp_kvdl_part_info *info;
229 	struct mlxsw_sp_kvdl_part *part;
230 	unsigned int nr_entries;
231 	size_t usage_size;
232 
233 	info = &kvdl_parts_info[part_index];
234 
235 	nr_entries = (info->end_index - info->start_index + 1) /
236 		     info->alloc_size;
237 	usage_size = BITS_TO_LONGS(nr_entries) * sizeof(unsigned long);
238 	part = kzalloc(sizeof(*part) + usage_size, GFP_KERNEL);
239 	if (!part)
240 		return -ENOMEM;
241 
242 	part->info = info;
243 	list_add(&part->list, &mlxsw_sp->kvdl->parts_list);
244 
245 	return 0;
246 }
247 
248 static void mlxsw_sp_kvdl_part_fini(struct mlxsw_sp *mlxsw_sp,
249 				    unsigned int part_index)
250 {
251 	struct mlxsw_sp_kvdl_part *part;
252 
253 	part = mlxsw_sp_kvdl_part_find(mlxsw_sp, part_index);
254 	if (!part)
255 		return;
256 
257 	list_del(&part->list);
258 	kfree(part);
259 }
260 
261 static int mlxsw_sp_kvdl_parts_init(struct mlxsw_sp *mlxsw_sp)
262 {
263 	int err, i;
264 
265 	INIT_LIST_HEAD(&mlxsw_sp->kvdl->parts_list);
266 
267 	for (i = 0; i < ARRAY_SIZE(kvdl_parts_info); i++) {
268 		err = mlxsw_sp_kvdl_part_init(mlxsw_sp, i);
269 		if (err)
270 			goto err_kvdl_part_init;
271 	}
272 
273 	return 0;
274 
275 err_kvdl_part_init:
276 	for (i--; i >= 0; i--)
277 		mlxsw_sp_kvdl_part_fini(mlxsw_sp, i);
278 	return err;
279 }
280 
281 static void mlxsw_sp_kvdl_parts_fini(struct mlxsw_sp *mlxsw_sp)
282 {
283 	int i;
284 
285 	for (i = ARRAY_SIZE(kvdl_parts_info) - 1; i >= 0; i--)
286 		mlxsw_sp_kvdl_part_fini(mlxsw_sp, i);
287 }
288 
289 static u64 mlxsw_sp_kvdl_part_occ(struct mlxsw_sp_kvdl_part *part)
290 {
291 	unsigned int nr_entries;
292 	int bit = -1;
293 	u64 occ = 0;
294 
295 	nr_entries = (part->info->end_index -
296 		      part->info->start_index + 1) /
297 		      part->info->alloc_size;
298 	while ((bit = find_next_bit(part->usage, nr_entries, bit + 1))
299 		< nr_entries)
300 		occ += part->info->alloc_size;
301 	return occ;
302 }
303 
304 u64 mlxsw_sp_kvdl_occ_get(const struct mlxsw_sp *mlxsw_sp)
305 {
306 	struct mlxsw_sp_kvdl_part *part;
307 	u64 occ = 0;
308 
309 	list_for_each_entry(part, &mlxsw_sp->kvdl->parts_list, list)
310 		occ += mlxsw_sp_kvdl_part_occ(part);
311 
312 	return occ;
313 }
314 
315 int mlxsw_sp_kvdl_init(struct mlxsw_sp *mlxsw_sp)
316 {
317 	struct mlxsw_sp_kvdl *kvdl;
318 	int err;
319 
320 	kvdl = kzalloc(sizeof(*mlxsw_sp->kvdl), GFP_KERNEL);
321 	if (!kvdl)
322 		return -ENOMEM;
323 	mlxsw_sp->kvdl = kvdl;
324 
325 	err = mlxsw_sp_kvdl_parts_init(mlxsw_sp);
326 	if (err)
327 		goto err_kvdl_parts_init;
328 
329 	return 0;
330 
331 err_kvdl_parts_init:
332 	kfree(mlxsw_sp->kvdl);
333 	return err;
334 }
335 
336 void mlxsw_sp_kvdl_fini(struct mlxsw_sp *mlxsw_sp)
337 {
338 	mlxsw_sp_kvdl_parts_fini(mlxsw_sp);
339 	kfree(mlxsw_sp->kvdl);
340 }
341