1 /* 1 /*
2 * lib/parman.c - Manager for linear priority 2 * lib/parman.c - Manager for linear priority array areas
3 * Copyright (c) 2017 Mellanox Technologies. A 3 * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
4 * Copyright (c) 2017 Jiri Pirko <jiri@mellano 4 * Copyright (c) 2017 Jiri Pirko <jiri@mellanox.com>
5 * 5 *
6 * Redistribution and use in source and binary 6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that t 7 * modification, are permitted provided that the following conditions are met:
8 * 8 *
9 * 1. Redistributions of source code must reta 9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the 10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must repr 11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the 12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials pro 13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the names of the copyright holde 14 * 3. Neither the names of the copyright holders nor the names of its
15 * contributors may be used to endorse or p 15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior wri 16 * this software without specific prior written permission.
17 * 17 *
18 * Alternatively, this software may be distrib 18 * Alternatively, this software may be distributed under the terms of the
19 * GNU General Public License ("GPL") version 19 * GNU General Public License ("GPL") version 2 as published by the Free
20 * Software Foundation. 20 * Software Foundation.
21 * 21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCL 23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND F 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYR 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL 26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT L 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THE 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUD 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31 * ARISING IN ANY WAY OUT OF THE USE OF THIS S 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE. 32 * POSSIBILITY OF SUCH DAMAGE.
33 */ 33 */
34 34
35 #include <linux/kernel.h> 35 #include <linux/kernel.h>
36 #include <linux/module.h> 36 #include <linux/module.h>
37 #include <linux/slab.h> 37 #include <linux/slab.h>
38 #include <linux/export.h> 38 #include <linux/export.h>
39 #include <linux/list.h> 39 #include <linux/list.h>
40 #include <linux/err.h> 40 #include <linux/err.h>
41 #include <linux/parman.h> 41 #include <linux/parman.h>
42 42
43 struct parman_algo { 43 struct parman_algo {
44 int (*item_add)(struct parman *parman, 44 int (*item_add)(struct parman *parman, struct parman_prio *prio,
45 struct parman_item *it 45 struct parman_item *item);
46 void (*item_remove)(struct parman *par 46 void (*item_remove)(struct parman *parman, struct parman_prio *prio,
47 struct parman_item 47 struct parman_item *item);
48 }; 48 };
49 49
50 struct parman { 50 struct parman {
51 const struct parman_ops *ops; 51 const struct parman_ops *ops;
52 void *priv; 52 void *priv;
53 const struct parman_algo *algo; 53 const struct parman_algo *algo;
54 unsigned long count; 54 unsigned long count;
55 unsigned long limit_count; 55 unsigned long limit_count;
56 struct list_head prio_list; 56 struct list_head prio_list;
57 }; 57 };
58 58
59 static int parman_enlarge(struct parman *parma 59 static int parman_enlarge(struct parman *parman)
60 { 60 {
61 unsigned long new_count = parman->limi 61 unsigned long new_count = parman->limit_count +
62 parman->ops- 62 parman->ops->resize_step;
63 int err; 63 int err;
64 64
65 err = parman->ops->resize(parman->priv 65 err = parman->ops->resize(parman->priv, new_count);
66 if (err) 66 if (err)
67 return err; 67 return err;
68 parman->limit_count = new_count; 68 parman->limit_count = new_count;
69 return 0; 69 return 0;
70 } 70 }
71 71
72 static int parman_shrink(struct parman *parman 72 static int parman_shrink(struct parman *parman)
73 { 73 {
74 unsigned long new_count = parman->limi 74 unsigned long new_count = parman->limit_count -
75 parman->ops- 75 parman->ops->resize_step;
76 int err; 76 int err;
77 77
78 if (new_count < parman->ops->base_coun 78 if (new_count < parman->ops->base_count)
79 return 0; 79 return 0;
80 err = parman->ops->resize(parman->priv 80 err = parman->ops->resize(parman->priv, new_count);
81 if (err) 81 if (err)
82 return err; 82 return err;
83 parman->limit_count = new_count; 83 parman->limit_count = new_count;
84 return 0; 84 return 0;
85 } 85 }
86 86
87 static bool parman_prio_used(struct parman_pri 87 static bool parman_prio_used(struct parman_prio *prio)
88 { 88 {
89 return !list_empty(&prio->item_list); 89 return !list_empty(&prio->item_list);
90 } 90 }
91 91
92 static struct parman_item *parman_prio_first_i 92 static struct parman_item *parman_prio_first_item(struct parman_prio *prio)
93 { 93 {
94 return list_first_entry(&prio->item_li 94 return list_first_entry(&prio->item_list,
95 typeof(struct 95 typeof(struct parman_item), list);
96 } 96 }
97 97
98 static unsigned long parman_prio_first_index(s 98 static unsigned long parman_prio_first_index(struct parman_prio *prio)
99 { 99 {
100 return parman_prio_first_item(prio)->i 100 return parman_prio_first_item(prio)->index;
101 } 101 }
102 102
103 static struct parman_item *parman_prio_last_it 103 static struct parman_item *parman_prio_last_item(struct parman_prio *prio)
104 { 104 {
105 return list_last_entry(&prio->item_lis 105 return list_last_entry(&prio->item_list,
106 typeof(struct p 106 typeof(struct parman_item), list);
107 } 107 }
108 108
109 static unsigned long parman_prio_last_index(st 109 static unsigned long parman_prio_last_index(struct parman_prio *prio)
110 { 110 {
111 return parman_prio_last_item(prio)->in 111 return parman_prio_last_item(prio)->index;
112 } 112 }
113 113
114 static unsigned long parman_lsort_new_index_fi 114 static unsigned long parman_lsort_new_index_find(struct parman *parman,
115 115 struct parman_prio *prio)
116 { 116 {
117 list_for_each_entry_from_reverse(prio, 117 list_for_each_entry_from_reverse(prio, &parman->prio_list, list) {
118 if (!parman_prio_used(prio)) 118 if (!parman_prio_used(prio))
119 continue; 119 continue;
120 return parman_prio_last_index( 120 return parman_prio_last_index(prio) + 1;
121 } 121 }
122 return 0; 122 return 0;
123 } 123 }
124 124
125 static void __parman_prio_move(struct parman * 125 static void __parman_prio_move(struct parman *parman, struct parman_prio *prio,
126 struct parman_i 126 struct parman_item *item, unsigned long to_index,
127 unsigned long c 127 unsigned long count)
128 { 128 {
129 parman->ops->move(parman->priv, item-> 129 parman->ops->move(parman->priv, item->index, to_index, count);
130 } 130 }
131 131
132 static void parman_prio_shift_down(struct parm 132 static void parman_prio_shift_down(struct parman *parman,
133 struct parm 133 struct parman_prio *prio)
134 { 134 {
135 struct parman_item *item; 135 struct parman_item *item;
136 unsigned long to_index; 136 unsigned long to_index;
137 137
138 if (!parman_prio_used(prio)) 138 if (!parman_prio_used(prio))
139 return; 139 return;
140 item = parman_prio_first_item(prio); 140 item = parman_prio_first_item(prio);
141 to_index = parman_prio_last_index(prio 141 to_index = parman_prio_last_index(prio) + 1;
142 __parman_prio_move(parman, prio, item, 142 __parman_prio_move(parman, prio, item, to_index, 1);
143 list_move_tail(&item->list, &prio->ite 143 list_move_tail(&item->list, &prio->item_list);
144 item->index = to_index; 144 item->index = to_index;
145 } 145 }
146 146
147 static void parman_prio_shift_up(struct parman 147 static void parman_prio_shift_up(struct parman *parman,
148 struct parman 148 struct parman_prio *prio)
149 { 149 {
150 struct parman_item *item; 150 struct parman_item *item;
151 unsigned long to_index; 151 unsigned long to_index;
152 152
153 if (!parman_prio_used(prio)) 153 if (!parman_prio_used(prio))
154 return; 154 return;
155 item = parman_prio_last_item(prio); 155 item = parman_prio_last_item(prio);
156 to_index = parman_prio_first_index(pri 156 to_index = parman_prio_first_index(prio) - 1;
157 __parman_prio_move(parman, prio, item, 157 __parman_prio_move(parman, prio, item, to_index, 1);
158 list_move(&item->list, &prio->item_lis 158 list_move(&item->list, &prio->item_list);
159 item->index = to_index; 159 item->index = to_index;
160 } 160 }
161 161
162 static void parman_prio_item_remove(struct par 162 static void parman_prio_item_remove(struct parman *parman,
163 struct par 163 struct parman_prio *prio,
164 struct par 164 struct parman_item *item)
165 { 165 {
166 struct parman_item *last_item; 166 struct parman_item *last_item;
167 unsigned long to_index; 167 unsigned long to_index;
168 168
169 last_item = parman_prio_last_item(prio 169 last_item = parman_prio_last_item(prio);
170 if (last_item == item) { 170 if (last_item == item) {
171 list_del(&item->list); 171 list_del(&item->list);
172 return; 172 return;
173 } 173 }
174 to_index = item->index; 174 to_index = item->index;
175 __parman_prio_move(parman, prio, last_ 175 __parman_prio_move(parman, prio, last_item, to_index, 1);
176 list_del(&last_item->list); 176 list_del(&last_item->list);
177 list_replace(&item->list, &last_item-> 177 list_replace(&item->list, &last_item->list);
178 last_item->index = to_index; 178 last_item->index = to_index;
179 } 179 }
180 180
181 static int parman_lsort_item_add(struct parman 181 static int parman_lsort_item_add(struct parman *parman,
182 struct parman 182 struct parman_prio *prio,
183 struct parman 183 struct parman_item *item)
184 { 184 {
185 struct parman_prio *prio2; 185 struct parman_prio *prio2;
186 unsigned long new_index; 186 unsigned long new_index;
187 int err; 187 int err;
188 188
189 if (parman->count + 1 > parman->limit_ 189 if (parman->count + 1 > parman->limit_count) {
190 err = parman_enlarge(parman); 190 err = parman_enlarge(parman);
191 if (err) 191 if (err)
192 return err; 192 return err;
193 } 193 }
194 194
195 new_index = parman_lsort_new_index_fin 195 new_index = parman_lsort_new_index_find(parman, prio);
196 list_for_each_entry_reverse(prio2, &pa 196 list_for_each_entry_reverse(prio2, &parman->prio_list, list) {
197 if (prio2 == prio) 197 if (prio2 == prio)
198 break; 198 break;
199 parman_prio_shift_down(parman, 199 parman_prio_shift_down(parman, prio2);
200 } 200 }
201 item->index = new_index; 201 item->index = new_index;
202 list_add_tail(&item->list, &prio->item 202 list_add_tail(&item->list, &prio->item_list);
203 parman->count++; 203 parman->count++;
204 return 0; 204 return 0;
205 } 205 }
206 206
207 static void parman_lsort_item_remove(struct pa 207 static void parman_lsort_item_remove(struct parman *parman,
208 struct pa 208 struct parman_prio *prio,
209 struct pa 209 struct parman_item *item)
210 { 210 {
211 parman_prio_item_remove(parman, prio, 211 parman_prio_item_remove(parman, prio, item);
212 list_for_each_entry_continue(prio, &pa 212 list_for_each_entry_continue(prio, &parman->prio_list, list)
213 parman_prio_shift_up(parman, p 213 parman_prio_shift_up(parman, prio);
214 parman->count--; 214 parman->count--;
215 if (parman->limit_count - parman->coun 215 if (parman->limit_count - parman->count >= parman->ops->resize_step)
216 parman_shrink(parman); 216 parman_shrink(parman);
217 } 217 }
218 218
219 static const struct parman_algo parman_lsort = 219 static const struct parman_algo parman_lsort = {
220 .item_add = parman_lsort_item_ad 220 .item_add = parman_lsort_item_add,
221 .item_remove = parman_lsort_item_re 221 .item_remove = parman_lsort_item_remove,
222 }; 222 };
223 223
224 static const struct parman_algo *parman_algos[ 224 static const struct parman_algo *parman_algos[] = {
225 &parman_lsort, 225 &parman_lsort,
226 }; 226 };
227 227
228 /** 228 /**
229 * parman_create - creates a new parman instan 229 * parman_create - creates a new parman instance
230 * @ops: caller-specific callbacks 230 * @ops: caller-specific callbacks
231 * @priv: pointer to a private data pass 231 * @priv: pointer to a private data passed to the ops
232 * 232 *
233 * Note: all locking must be provided by the c 233 * Note: all locking must be provided by the caller.
234 * 234 *
235 * Each parman instance manages an array area 235 * Each parman instance manages an array area with chunks of entries
236 * with the same priority. Consider following 236 * with the same priority. Consider following example:
237 * 237 *
238 * item 1 with prio 10 238 * item 1 with prio 10
239 * item 2 with prio 10 239 * item 2 with prio 10
240 * item 3 with prio 10 240 * item 3 with prio 10
241 * item 4 with prio 20 241 * item 4 with prio 20
242 * item 5 with prio 20 242 * item 5 with prio 20
243 * item 6 with prio 30 243 * item 6 with prio 30
244 * item 7 with prio 30 244 * item 7 with prio 30
245 * item 8 with prio 30 245 * item 8 with prio 30
246 * 246 *
247 * In this example, there are 3 priority chunk 247 * In this example, there are 3 priority chunks. The order of the priorities
248 * matters, however the order of items within 248 * matters, however the order of items within a single priority chunk does not
249 * matter. So the same array could be ordered 249 * matter. So the same array could be ordered as follows:
250 * 250 *
251 * item 2 with prio 10 251 * item 2 with prio 10
252 * item 3 with prio 10 252 * item 3 with prio 10
253 * item 1 with prio 10 253 * item 1 with prio 10
254 * item 5 with prio 20 254 * item 5 with prio 20
255 * item 4 with prio 20 255 * item 4 with prio 20
256 * item 7 with prio 30 256 * item 7 with prio 30
257 * item 8 with prio 30 257 * item 8 with prio 30
258 * item 6 with prio 30 258 * item 6 with prio 30
259 * 259 *
260 * The goal of parman is to maintain the prior 260 * The goal of parman is to maintain the priority ordering. The caller
261 * provides @ops with callbacks parman uses to 261 * provides @ops with callbacks parman uses to move the items
262 * and resize the array area. 262 * and resize the array area.
263 * 263 *
264 * Returns a pointer to newly created parman i 264 * Returns a pointer to newly created parman instance in case of success,
265 * otherwise it returns NULL. 265 * otherwise it returns NULL.
266 */ 266 */
267 struct parman *parman_create(const struct parm 267 struct parman *parman_create(const struct parman_ops *ops, void *priv)
268 { 268 {
269 struct parman *parman; 269 struct parman *parman;
270 270
271 parman = kzalloc(sizeof(*parman), GFP_ 271 parman = kzalloc(sizeof(*parman), GFP_KERNEL);
272 if (!parman) 272 if (!parman)
273 return NULL; 273 return NULL;
274 INIT_LIST_HEAD(&parman->prio_list); 274 INIT_LIST_HEAD(&parman->prio_list);
275 parman->ops = ops; 275 parman->ops = ops;
276 parman->priv = priv; 276 parman->priv = priv;
277 parman->limit_count = ops->base_count; 277 parman->limit_count = ops->base_count;
278 parman->algo = parman_algos[ops->algo] 278 parman->algo = parman_algos[ops->algo];
279 return parman; 279 return parman;
280 } 280 }
281 EXPORT_SYMBOL(parman_create); 281 EXPORT_SYMBOL(parman_create);
282 282
283 /** 283 /**
284 * parman_destroy - destroys existing parman i 284 * parman_destroy - destroys existing parman instance
285 * @parman: parman instance 285 * @parman: parman instance
286 * 286 *
287 * Note: all locking must be provided by the c 287 * Note: all locking must be provided by the caller.
288 */ 288 */
289 void parman_destroy(struct parman *parman) 289 void parman_destroy(struct parman *parman)
290 { 290 {
291 WARN_ON(!list_empty(&parman->prio_list 291 WARN_ON(!list_empty(&parman->prio_list));
292 kfree(parman); 292 kfree(parman);
293 } 293 }
294 EXPORT_SYMBOL(parman_destroy); 294 EXPORT_SYMBOL(parman_destroy);
295 295
296 /** 296 /**
297 * parman_prio_init - initializes a parman pri 297 * parman_prio_init - initializes a parman priority chunk
298 * @parman: parman instance 298 * @parman: parman instance
299 * @prio: parman prio structure to be in 299 * @prio: parman prio structure to be initialized
300 * @priority: desired priority of the chunk 300 * @priority: desired priority of the chunk
301 * 301 *
302 * Note: all locking must be provided by the c 302 * Note: all locking must be provided by the caller.
303 * 303 *
304 * Before caller could add an item with certai 304 * Before caller could add an item with certain priority, he has to
305 * initialize a priority chunk for it using th 305 * initialize a priority chunk for it using this function.
306 */ 306 */
307 void parman_prio_init(struct parman *parman, s 307 void parman_prio_init(struct parman *parman, struct parman_prio *prio,
308 unsigned long priority) 308 unsigned long priority)
309 { 309 {
310 struct parman_prio *prio2; 310 struct parman_prio *prio2;
311 struct list_head *pos; 311 struct list_head *pos;
312 312
313 INIT_LIST_HEAD(&prio->item_list); 313 INIT_LIST_HEAD(&prio->item_list);
314 prio->priority = priority; 314 prio->priority = priority;
315 315
316 /* Position inside the list according 316 /* Position inside the list according to priority */
317 list_for_each(pos, &parman->prio_list) 317 list_for_each(pos, &parman->prio_list) {
318 prio2 = list_entry(pos, typeof 318 prio2 = list_entry(pos, typeof(*prio2), list);
319 if (prio2->priority > prio->pr 319 if (prio2->priority > prio->priority)
320 break; 320 break;
321 } 321 }
322 list_add_tail(&prio->list, pos); 322 list_add_tail(&prio->list, pos);
323 } 323 }
324 EXPORT_SYMBOL(parman_prio_init); 324 EXPORT_SYMBOL(parman_prio_init);
325 325
326 /** 326 /**
327 * parman_prio_fini - finalizes use of parman 327 * parman_prio_fini - finalizes use of parman priority chunk
328 * @prio: parman prio structure 328 * @prio: parman prio structure
329 * 329 *
330 * Note: all locking must be provided by the c 330 * Note: all locking must be provided by the caller.
331 */ 331 */
332 void parman_prio_fini(struct parman_prio *prio 332 void parman_prio_fini(struct parman_prio *prio)
333 { 333 {
334 WARN_ON(parman_prio_used(prio)); 334 WARN_ON(parman_prio_used(prio));
335 list_del(&prio->list); 335 list_del(&prio->list);
336 } 336 }
337 EXPORT_SYMBOL(parman_prio_fini); 337 EXPORT_SYMBOL(parman_prio_fini);
338 338
339 /** 339 /**
340 * parman_item_add - adds a parman item under 340 * parman_item_add - adds a parman item under defined priority
341 * @parman: parman instance 341 * @parman: parman instance
342 * @prio: parman prio instance to add th 342 * @prio: parman prio instance to add the item to
343 * @item: parman item instance 343 * @item: parman item instance
344 * 344 *
345 * Note: all locking must be provided by the c 345 * Note: all locking must be provided by the caller.
346 * 346 *
347 * Adds item to a array managed by parman inst 347 * Adds item to a array managed by parman instance under the specified priority.
348 * 348 *
349 * Returns 0 in case of success, negative numb 349 * Returns 0 in case of success, negative number to indicate an error.
350 */ 350 */
351 int parman_item_add(struct parman *parman, str 351 int parman_item_add(struct parman *parman, struct parman_prio *prio,
352 struct parman_item *item) 352 struct parman_item *item)
353 { 353 {
354 return parman->algo->item_add(parman, 354 return parman->algo->item_add(parman, prio, item);
355 } 355 }
356 EXPORT_SYMBOL(parman_item_add); 356 EXPORT_SYMBOL(parman_item_add);
357 357
358 /** 358 /**
359 * parman_item_remove - deletes parman item 359 * parman_item_remove - deletes parman item
360 * @parman: parman instance 360 * @parman: parman instance
361 * @prio: parman prio instance to delete 361 * @prio: parman prio instance to delete the item from
362 * @item: parman item instance 362 * @item: parman item instance
363 * 363 *
364 * Note: all locking must be provided by the c 364 * Note: all locking must be provided by the caller.
365 */ 365 */
366 void parman_item_remove(struct parman *parman, 366 void parman_item_remove(struct parman *parman, struct parman_prio *prio,
367 struct parman_item *it 367 struct parman_item *item)
368 { 368 {
369 parman->algo->item_remove(parman, prio 369 parman->algo->item_remove(parman, prio, item);
370 } 370 }
371 EXPORT_SYMBOL(parman_item_remove); 371 EXPORT_SYMBOL(parman_item_remove);
372 372
373 MODULE_LICENSE("Dual BSD/GPL"); 373 MODULE_LICENSE("Dual BSD/GPL");
374 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>" 374 MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
375 MODULE_DESCRIPTION("Priority-based array manag 375 MODULE_DESCRIPTION("Priority-based array manager");
376 376
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