1 /*
2  * drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c
3  * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
4  * Copyright (c) 2017 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/slab.h>
37 #include <linux/list.h>
38 #include <linux/errno.h>
39 
40 #include "item.h"
41 #include "core_acl_flex_keys.h"
42 
43 struct mlxsw_afk {
44 	struct list_head key_info_list;
45 	unsigned int max_blocks;
46 	const struct mlxsw_afk_block *blocks;
47 	unsigned int blocks_count;
48 };
49 
50 static bool mlxsw_afk_blocks_check(struct mlxsw_afk *mlxsw_afk)
51 {
52 	int i;
53 	int j;
54 
55 	for (i = 0; i < mlxsw_afk->blocks_count; i++) {
56 		const struct mlxsw_afk_block *block = &mlxsw_afk->blocks[i];
57 
58 		for (j = 0; j < block->instances_count; j++) {
59 			struct mlxsw_afk_element_inst *elinst;
60 
61 			elinst = &block->instances[j];
62 			if (elinst->type != elinst->info->type ||
63 			    elinst->item.size.bits !=
64 			    elinst->info->item.size.bits)
65 				return false;
66 		}
67 	}
68 	return true;
69 }
70 
71 struct mlxsw_afk *mlxsw_afk_create(unsigned int max_blocks,
72 				   const struct mlxsw_afk_block *blocks,
73 				   unsigned int blocks_count)
74 {
75 	struct mlxsw_afk *mlxsw_afk;
76 
77 	mlxsw_afk = kzalloc(sizeof(*mlxsw_afk), GFP_KERNEL);
78 	if (!mlxsw_afk)
79 		return NULL;
80 	INIT_LIST_HEAD(&mlxsw_afk->key_info_list);
81 	mlxsw_afk->max_blocks = max_blocks;
82 	mlxsw_afk->blocks = blocks;
83 	mlxsw_afk->blocks_count = blocks_count;
84 	WARN_ON(!mlxsw_afk_blocks_check(mlxsw_afk));
85 	return mlxsw_afk;
86 }
87 EXPORT_SYMBOL(mlxsw_afk_create);
88 
89 void mlxsw_afk_destroy(struct mlxsw_afk *mlxsw_afk)
90 {
91 	WARN_ON(!list_empty(&mlxsw_afk->key_info_list));
92 	kfree(mlxsw_afk);
93 }
94 EXPORT_SYMBOL(mlxsw_afk_destroy);
95 
96 struct mlxsw_afk_key_info {
97 	struct list_head list;
98 	unsigned int ref_count;
99 	unsigned int blocks_count;
100 	int element_to_block[MLXSW_AFK_ELEMENT_MAX]; /* index is element, value
101 						      * is index inside "blocks"
102 						      */
103 	struct mlxsw_afk_element_usage elusage;
104 	const struct mlxsw_afk_block *blocks[0];
105 };
106 
107 static bool
108 mlxsw_afk_key_info_elements_eq(struct mlxsw_afk_key_info *key_info,
109 			       struct mlxsw_afk_element_usage *elusage)
110 {
111 	return memcmp(&key_info->elusage, elusage, sizeof(*elusage)) == 0;
112 }
113 
114 static struct mlxsw_afk_key_info *
115 mlxsw_afk_key_info_find(struct mlxsw_afk *mlxsw_afk,
116 			struct mlxsw_afk_element_usage *elusage)
117 {
118 	struct mlxsw_afk_key_info *key_info;
119 
120 	list_for_each_entry(key_info, &mlxsw_afk->key_info_list, list) {
121 		if (mlxsw_afk_key_info_elements_eq(key_info, elusage))
122 			return key_info;
123 	}
124 	return NULL;
125 }
126 
127 struct mlxsw_afk_picker {
128 	struct {
129 		DECLARE_BITMAP(element, MLXSW_AFK_ELEMENT_MAX);
130 		unsigned int total;
131 	} hits[0];
132 };
133 
134 static void mlxsw_afk_picker_count_hits(struct mlxsw_afk *mlxsw_afk,
135 					struct mlxsw_afk_picker *picker,
136 					enum mlxsw_afk_element element)
137 {
138 	int i;
139 	int j;
140 
141 	for (i = 0; i < mlxsw_afk->blocks_count; i++) {
142 		const struct mlxsw_afk_block *block = &mlxsw_afk->blocks[i];
143 
144 		for (j = 0; j < block->instances_count; j++) {
145 			struct mlxsw_afk_element_inst *elinst;
146 
147 			elinst = &block->instances[j];
148 			if (elinst->info->element == element) {
149 				__set_bit(element, picker->hits[i].element);
150 				picker->hits[i].total++;
151 			}
152 		}
153 	}
154 }
155 
156 static void mlxsw_afk_picker_subtract_hits(struct mlxsw_afk *mlxsw_afk,
157 					   struct mlxsw_afk_picker *picker,
158 					   int block_index)
159 {
160 	DECLARE_BITMAP(hits_element, MLXSW_AFK_ELEMENT_MAX);
161 	int i;
162 	int j;
163 
164 	memcpy(&hits_element, &picker->hits[block_index].element,
165 	       sizeof(hits_element));
166 
167 	for (i = 0; i < mlxsw_afk->blocks_count; i++) {
168 		for_each_set_bit(j, hits_element, MLXSW_AFK_ELEMENT_MAX) {
169 			if (__test_and_clear_bit(j, picker->hits[i].element))
170 				picker->hits[i].total--;
171 		}
172 	}
173 }
174 
175 static int mlxsw_afk_picker_most_hits_get(struct mlxsw_afk *mlxsw_afk,
176 					  struct mlxsw_afk_picker *picker)
177 {
178 	int most_index = -EINVAL; /* Should never happen to return this */
179 	int most_hits = 0;
180 	int i;
181 
182 	for (i = 0; i < mlxsw_afk->blocks_count; i++) {
183 		if (picker->hits[i].total > most_hits) {
184 			most_hits = picker->hits[i].total;
185 			most_index = i;
186 		}
187 	}
188 	return most_index;
189 }
190 
191 static int mlxsw_afk_picker_key_info_add(struct mlxsw_afk *mlxsw_afk,
192 					 struct mlxsw_afk_picker *picker,
193 					 int block_index,
194 					 struct mlxsw_afk_key_info *key_info)
195 {
196 	enum mlxsw_afk_element element;
197 
198 	if (key_info->blocks_count == mlxsw_afk->max_blocks)
199 		return -EINVAL;
200 
201 	for_each_set_bit(element, picker->hits[block_index].element,
202 			 MLXSW_AFK_ELEMENT_MAX) {
203 		key_info->element_to_block[element] = key_info->blocks_count;
204 		mlxsw_afk_element_usage_add(&key_info->elusage, element);
205 	}
206 
207 	key_info->blocks[key_info->blocks_count] =
208 					&mlxsw_afk->blocks[block_index];
209 	key_info->blocks_count++;
210 	return 0;
211 }
212 
213 static int mlxsw_afk_picker(struct mlxsw_afk *mlxsw_afk,
214 			    struct mlxsw_afk_key_info *key_info,
215 			    struct mlxsw_afk_element_usage *elusage)
216 {
217 	struct mlxsw_afk_picker *picker;
218 	enum mlxsw_afk_element element;
219 	size_t alloc_size;
220 	int err;
221 
222 	alloc_size = sizeof(picker->hits[0]) * mlxsw_afk->blocks_count;
223 	picker = kzalloc(alloc_size, GFP_KERNEL);
224 	if (!picker)
225 		return -ENOMEM;
226 
227 	/* Since the same elements could be present in multiple blocks,
228 	 * we must find out optimal block list in order to make the
229 	 * block count as low as possible.
230 	 *
231 	 * First, we count hits. We go over all available blocks and count
232 	 * how many of requested elements are covered by each.
233 	 *
234 	 * Then in loop, we find block with most hits and add it to
235 	 * output key_info. Then we have to subtract this block hits so
236 	 * the next iteration will find most suitable block for
237 	 * the rest of requested elements.
238 	 */
239 
240 	mlxsw_afk_element_usage_for_each(element, elusage)
241 		mlxsw_afk_picker_count_hits(mlxsw_afk, picker, element);
242 
243 	do {
244 		int block_index;
245 
246 		block_index = mlxsw_afk_picker_most_hits_get(mlxsw_afk, picker);
247 		if (block_index < 0) {
248 			err = block_index;
249 			goto out;
250 		}
251 		err = mlxsw_afk_picker_key_info_add(mlxsw_afk, picker,
252 						    block_index, key_info);
253 		if (err)
254 			goto out;
255 		mlxsw_afk_picker_subtract_hits(mlxsw_afk, picker, block_index);
256 	} while (!mlxsw_afk_key_info_elements_eq(key_info, elusage));
257 
258 	err = 0;
259 out:
260 	kfree(picker);
261 	return err;
262 }
263 
264 static struct mlxsw_afk_key_info *
265 mlxsw_afk_key_info_create(struct mlxsw_afk *mlxsw_afk,
266 			  struct mlxsw_afk_element_usage *elusage)
267 {
268 	struct mlxsw_afk_key_info *key_info;
269 	size_t alloc_size;
270 	int err;
271 
272 	alloc_size = sizeof(*key_info) +
273 		     sizeof(key_info->blocks[0]) * mlxsw_afk->max_blocks;
274 	key_info = kzalloc(alloc_size, GFP_KERNEL);
275 	if (!key_info)
276 		return ERR_PTR(-ENOMEM);
277 	err = mlxsw_afk_picker(mlxsw_afk, key_info, elusage);
278 	if (err)
279 		goto err_picker;
280 	list_add(&key_info->list, &mlxsw_afk->key_info_list);
281 	key_info->ref_count = 1;
282 	return key_info;
283 
284 err_picker:
285 	kfree(key_info);
286 	return ERR_PTR(err);
287 }
288 
289 static void mlxsw_afk_key_info_destroy(struct mlxsw_afk_key_info *key_info)
290 {
291 	list_del(&key_info->list);
292 	kfree(key_info);
293 }
294 
295 struct mlxsw_afk_key_info *
296 mlxsw_afk_key_info_get(struct mlxsw_afk *mlxsw_afk,
297 		       struct mlxsw_afk_element_usage *elusage)
298 {
299 	struct mlxsw_afk_key_info *key_info;
300 
301 	key_info = mlxsw_afk_key_info_find(mlxsw_afk, elusage);
302 	if (key_info) {
303 		key_info->ref_count++;
304 		return key_info;
305 	}
306 	return mlxsw_afk_key_info_create(mlxsw_afk, elusage);
307 }
308 EXPORT_SYMBOL(mlxsw_afk_key_info_get);
309 
310 void mlxsw_afk_key_info_put(struct mlxsw_afk_key_info *key_info)
311 {
312 	if (--key_info->ref_count)
313 		return;
314 	mlxsw_afk_key_info_destroy(key_info);
315 }
316 EXPORT_SYMBOL(mlxsw_afk_key_info_put);
317 
318 bool mlxsw_afk_key_info_subset(struct mlxsw_afk_key_info *key_info,
319 			       struct mlxsw_afk_element_usage *elusage)
320 {
321 	return mlxsw_afk_element_usage_subset(elusage, &key_info->elusage);
322 }
323 EXPORT_SYMBOL(mlxsw_afk_key_info_subset);
324 
325 static const struct mlxsw_afk_element_inst *
326 mlxsw_afk_block_elinst_get(const struct mlxsw_afk_block *block,
327 			   enum mlxsw_afk_element element)
328 {
329 	int i;
330 
331 	for (i = 0; i < block->instances_count; i++) {
332 		struct mlxsw_afk_element_inst *elinst;
333 
334 		elinst = &block->instances[i];
335 		if (elinst->info->element == element)
336 			return elinst;
337 	}
338 	return NULL;
339 }
340 
341 static const struct mlxsw_afk_element_inst *
342 mlxsw_afk_key_info_elinst_get(struct mlxsw_afk_key_info *key_info,
343 			      enum mlxsw_afk_element element,
344 			      int *p_block_index)
345 {
346 	const struct mlxsw_afk_element_inst *elinst;
347 	const struct mlxsw_afk_block *block;
348 	int block_index;
349 
350 	if (WARN_ON(!test_bit(element, key_info->elusage.usage)))
351 		return NULL;
352 	block_index = key_info->element_to_block[element];
353 	block = key_info->blocks[block_index];
354 
355 	elinst = mlxsw_afk_block_elinst_get(block, element);
356 	if (WARN_ON(!elinst))
357 		return NULL;
358 
359 	*p_block_index = block_index;
360 	return elinst;
361 }
362 
363 u16
364 mlxsw_afk_key_info_block_encoding_get(const struct mlxsw_afk_key_info *key_info,
365 				      int block_index)
366 {
367 	return key_info->blocks[block_index]->encoding;
368 }
369 EXPORT_SYMBOL(mlxsw_afk_key_info_block_encoding_get);
370 
371 unsigned int
372 mlxsw_afk_key_info_blocks_count_get(const struct mlxsw_afk_key_info *key_info)
373 {
374 	return key_info->blocks_count;
375 }
376 EXPORT_SYMBOL(mlxsw_afk_key_info_blocks_count_get);
377 
378 void mlxsw_afk_values_add_u32(struct mlxsw_afk_element_values *values,
379 			      enum mlxsw_afk_element element,
380 			      u32 key_value, u32 mask_value)
381 {
382 	const struct mlxsw_afk_element_info *elinfo =
383 				&mlxsw_afk_element_infos[element];
384 	const struct mlxsw_item *storage_item = &elinfo->item;
385 
386 	if (!mask_value)
387 		return;
388 	if (WARN_ON(elinfo->type != MLXSW_AFK_ELEMENT_TYPE_U32))
389 		return;
390 	__mlxsw_item_set32(values->storage.key, storage_item, 0, key_value);
391 	__mlxsw_item_set32(values->storage.mask, storage_item, 0, mask_value);
392 	mlxsw_afk_element_usage_add(&values->elusage, element);
393 }
394 EXPORT_SYMBOL(mlxsw_afk_values_add_u32);
395 
396 void mlxsw_afk_values_add_buf(struct mlxsw_afk_element_values *values,
397 			      enum mlxsw_afk_element element,
398 			      const char *key_value, const char *mask_value,
399 			      unsigned int len)
400 {
401 	const struct mlxsw_afk_element_info *elinfo =
402 				&mlxsw_afk_element_infos[element];
403 	const struct mlxsw_item *storage_item = &elinfo->item;
404 
405 	if (!memchr_inv(mask_value, 0, len)) /* If mask is zero */
406 		return;
407 	if (WARN_ON(elinfo->type != MLXSW_AFK_ELEMENT_TYPE_BUF) ||
408 	    WARN_ON(elinfo->item.size.bytes != len))
409 		return;
410 	__mlxsw_item_memcpy_to(values->storage.key, key_value,
411 			       storage_item, 0);
412 	__mlxsw_item_memcpy_to(values->storage.mask, mask_value,
413 			       storage_item, 0);
414 	mlxsw_afk_element_usage_add(&values->elusage, element);
415 }
416 EXPORT_SYMBOL(mlxsw_afk_values_add_buf);
417 
418 static void mlxsw_afk_encode_u32(const struct mlxsw_item *storage_item,
419 				 const struct mlxsw_item *output_item,
420 				 char *storage, char *output_indexed)
421 {
422 	u32 value;
423 
424 	value = __mlxsw_item_get32(storage, storage_item, 0);
425 	__mlxsw_item_set32(output_indexed, output_item, 0, value);
426 }
427 
428 static void mlxsw_afk_encode_buf(const struct mlxsw_item *storage_item,
429 				 const struct mlxsw_item *output_item,
430 				 char *storage, char *output_indexed)
431 {
432 	char *storage_data = __mlxsw_item_data(storage, storage_item, 0);
433 	char *output_data = __mlxsw_item_data(output_indexed, output_item, 0);
434 	size_t len = output_item->size.bytes;
435 
436 	memcpy(output_data, storage_data, len);
437 }
438 
439 #define MLXSW_AFK_KEY_BLOCK_SIZE 16
440 
441 static void mlxsw_afk_encode_one(const struct mlxsw_afk_element_inst *elinst,
442 				 int block_index, char *storage, char *output)
443 {
444 	char *output_indexed = output + block_index * MLXSW_AFK_KEY_BLOCK_SIZE;
445 	const struct mlxsw_item *storage_item = &elinst->info->item;
446 	const struct mlxsw_item *output_item = &elinst->item;
447 
448 	if (elinst->type == MLXSW_AFK_ELEMENT_TYPE_U32)
449 		mlxsw_afk_encode_u32(storage_item, output_item,
450 				     storage, output_indexed);
451 	else if (elinst->type == MLXSW_AFK_ELEMENT_TYPE_BUF)
452 		mlxsw_afk_encode_buf(storage_item, output_item,
453 				     storage, output_indexed);
454 }
455 
456 void mlxsw_afk_encode(struct mlxsw_afk_key_info *key_info,
457 		      struct mlxsw_afk_element_values *values,
458 		      char *key, char *mask)
459 {
460 	const struct mlxsw_afk_element_inst *elinst;
461 	enum mlxsw_afk_element element;
462 	int block_index;
463 
464 	mlxsw_afk_element_usage_for_each(element, &values->elusage) {
465 		elinst = mlxsw_afk_key_info_elinst_get(key_info, element,
466 						       &block_index);
467 		if (!elinst)
468 			continue;
469 		mlxsw_afk_encode_one(elinst, block_index,
470 				     values->storage.key, key);
471 		mlxsw_afk_encode_one(elinst, block_index,
472 				     values->storage.mask, mask);
473 	}
474 }
475 EXPORT_SYMBOL(mlxsw_afk_encode);
476