1 /* 2 * Copyright (c) 2008, Intel Corporation. 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 11 * more details. 12 * 13 * You should have received a copy of the GNU General Public License along with 14 * this program; if not, see <http://www.gnu.org/licenses/>. 15 * 16 * Author: Alexander Duyck <alexander.h.duyck@intel.com> 17 */ 18 19 #include <linux/module.h> 20 #include <linux/slab.h> 21 #include <linux/types.h> 22 #include <linux/kernel.h> 23 #include <linux/string.h> 24 #include <linux/errno.h> 25 #include <linux/skbuff.h> 26 #include <net/netlink.h> 27 #include <net/pkt_sched.h> 28 #include <net/pkt_cls.h> 29 30 struct multiq_sched_data { 31 u16 bands; 32 u16 max_bands; 33 u16 curband; 34 struct tcf_proto __rcu *filter_list; 35 struct tcf_block *block; 36 struct Qdisc **queues; 37 }; 38 39 40 static struct Qdisc * 41 multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) 42 { 43 struct multiq_sched_data *q = qdisc_priv(sch); 44 u32 band; 45 struct tcf_result res; 46 struct tcf_proto *fl = rcu_dereference_bh(q->filter_list); 47 int err; 48 49 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 50 err = tcf_classify(skb, fl, &res, false); 51 #ifdef CONFIG_NET_CLS_ACT 52 switch (err) { 53 case TC_ACT_STOLEN: 54 case TC_ACT_QUEUED: 55 case TC_ACT_TRAP: 56 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 57 case TC_ACT_SHOT: 58 return NULL; 59 } 60 #endif 61 band = skb_get_queue_mapping(skb); 62 63 if (band >= q->bands) 64 return q->queues[0]; 65 66 return q->queues[band]; 67 } 68 69 static int 70 multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 71 struct sk_buff **to_free) 72 { 73 struct Qdisc *qdisc; 74 int ret; 75 76 qdisc = multiq_classify(skb, sch, &ret); 77 #ifdef CONFIG_NET_CLS_ACT 78 if (qdisc == NULL) { 79 80 if (ret & __NET_XMIT_BYPASS) 81 qdisc_qstats_drop(sch); 82 __qdisc_drop(skb, to_free); 83 return ret; 84 } 85 #endif 86 87 ret = qdisc_enqueue(skb, qdisc, to_free); 88 if (ret == NET_XMIT_SUCCESS) { 89 sch->q.qlen++; 90 return NET_XMIT_SUCCESS; 91 } 92 if (net_xmit_drop_count(ret)) 93 qdisc_qstats_drop(sch); 94 return ret; 95 } 96 97 static struct sk_buff *multiq_dequeue(struct Qdisc *sch) 98 { 99 struct multiq_sched_data *q = qdisc_priv(sch); 100 struct Qdisc *qdisc; 101 struct sk_buff *skb; 102 int band; 103 104 for (band = 0; band < q->bands; band++) { 105 /* cycle through bands to ensure fairness */ 106 q->curband++; 107 if (q->curband >= q->bands) 108 q->curband = 0; 109 110 /* Check that target subqueue is available before 111 * pulling an skb to avoid head-of-line blocking. 112 */ 113 if (!netif_xmit_stopped( 114 netdev_get_tx_queue(qdisc_dev(sch), q->curband))) { 115 qdisc = q->queues[q->curband]; 116 skb = qdisc->dequeue(qdisc); 117 if (skb) { 118 qdisc_bstats_update(sch, skb); 119 sch->q.qlen--; 120 return skb; 121 } 122 } 123 } 124 return NULL; 125 126 } 127 128 static struct sk_buff *multiq_peek(struct Qdisc *sch) 129 { 130 struct multiq_sched_data *q = qdisc_priv(sch); 131 unsigned int curband = q->curband; 132 struct Qdisc *qdisc; 133 struct sk_buff *skb; 134 int band; 135 136 for (band = 0; band < q->bands; band++) { 137 /* cycle through bands to ensure fairness */ 138 curband++; 139 if (curband >= q->bands) 140 curband = 0; 141 142 /* Check that target subqueue is available before 143 * pulling an skb to avoid head-of-line blocking. 144 */ 145 if (!netif_xmit_stopped( 146 netdev_get_tx_queue(qdisc_dev(sch), curband))) { 147 qdisc = q->queues[curband]; 148 skb = qdisc->ops->peek(qdisc); 149 if (skb) 150 return skb; 151 } 152 } 153 return NULL; 154 155 } 156 157 static void 158 multiq_reset(struct Qdisc *sch) 159 { 160 u16 band; 161 struct multiq_sched_data *q = qdisc_priv(sch); 162 163 for (band = 0; band < q->bands; band++) 164 qdisc_reset(q->queues[band]); 165 sch->q.qlen = 0; 166 q->curband = 0; 167 } 168 169 static void 170 multiq_destroy(struct Qdisc *sch) 171 { 172 int band; 173 struct multiq_sched_data *q = qdisc_priv(sch); 174 175 tcf_block_put(q->block); 176 for (band = 0; band < q->bands; band++) 177 qdisc_destroy(q->queues[band]); 178 179 kfree(q->queues); 180 } 181 182 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) 183 { 184 struct multiq_sched_data *q = qdisc_priv(sch); 185 struct tc_multiq_qopt *qopt; 186 int i; 187 188 if (!netif_is_multiqueue(qdisc_dev(sch))) 189 return -EOPNOTSUPP; 190 if (nla_len(opt) < sizeof(*qopt)) 191 return -EINVAL; 192 193 qopt = nla_data(opt); 194 195 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 196 197 sch_tree_lock(sch); 198 q->bands = qopt->bands; 199 for (i = q->bands; i < q->max_bands; i++) { 200 if (q->queues[i] != &noop_qdisc) { 201 struct Qdisc *child = q->queues[i]; 202 q->queues[i] = &noop_qdisc; 203 qdisc_tree_reduce_backlog(child, child->q.qlen, 204 child->qstats.backlog); 205 qdisc_destroy(child); 206 } 207 } 208 209 sch_tree_unlock(sch); 210 211 for (i = 0; i < q->bands; i++) { 212 if (q->queues[i] == &noop_qdisc) { 213 struct Qdisc *child, *old; 214 child = qdisc_create_dflt(sch->dev_queue, 215 &pfifo_qdisc_ops, 216 TC_H_MAKE(sch->handle, 217 i + 1)); 218 if (child) { 219 sch_tree_lock(sch); 220 old = q->queues[i]; 221 q->queues[i] = child; 222 if (child != &noop_qdisc) 223 qdisc_hash_add(child, true); 224 225 if (old != &noop_qdisc) { 226 qdisc_tree_reduce_backlog(old, 227 old->q.qlen, 228 old->qstats.backlog); 229 qdisc_destroy(old); 230 } 231 sch_tree_unlock(sch); 232 } 233 } 234 } 235 return 0; 236 } 237 238 static int multiq_init(struct Qdisc *sch, struct nlattr *opt) 239 { 240 struct multiq_sched_data *q = qdisc_priv(sch); 241 int i, err; 242 243 q->queues = NULL; 244 245 if (opt == NULL) 246 return -EINVAL; 247 248 err = tcf_block_get(&q->block, &q->filter_list); 249 if (err) 250 return err; 251 252 q->max_bands = qdisc_dev(sch)->num_tx_queues; 253 254 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 255 if (!q->queues) 256 return -ENOBUFS; 257 for (i = 0; i < q->max_bands; i++) 258 q->queues[i] = &noop_qdisc; 259 260 err = multiq_tune(sch, opt); 261 262 if (err) 263 kfree(q->queues); 264 265 return err; 266 } 267 268 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 269 { 270 struct multiq_sched_data *q = qdisc_priv(sch); 271 unsigned char *b = skb_tail_pointer(skb); 272 struct tc_multiq_qopt opt; 273 274 opt.bands = q->bands; 275 opt.max_bands = q->max_bands; 276 277 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 278 goto nla_put_failure; 279 280 return skb->len; 281 282 nla_put_failure: 283 nlmsg_trim(skb, b); 284 return -1; 285 } 286 287 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 288 struct Qdisc **old) 289 { 290 struct multiq_sched_data *q = qdisc_priv(sch); 291 unsigned long band = arg - 1; 292 293 if (new == NULL) 294 new = &noop_qdisc; 295 296 *old = qdisc_replace(sch, new, &q->queues[band]); 297 return 0; 298 } 299 300 static struct Qdisc * 301 multiq_leaf(struct Qdisc *sch, unsigned long arg) 302 { 303 struct multiq_sched_data *q = qdisc_priv(sch); 304 unsigned long band = arg - 1; 305 306 return q->queues[band]; 307 } 308 309 static unsigned long multiq_get(struct Qdisc *sch, u32 classid) 310 { 311 struct multiq_sched_data *q = qdisc_priv(sch); 312 unsigned long band = TC_H_MIN(classid); 313 314 if (band - 1 >= q->bands) 315 return 0; 316 return band; 317 } 318 319 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 320 u32 classid) 321 { 322 return multiq_get(sch, classid); 323 } 324 325 326 static void multiq_put(struct Qdisc *q, unsigned long cl) 327 { 328 } 329 330 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 331 struct sk_buff *skb, struct tcmsg *tcm) 332 { 333 struct multiq_sched_data *q = qdisc_priv(sch); 334 335 tcm->tcm_handle |= TC_H_MIN(cl); 336 tcm->tcm_info = q->queues[cl - 1]->handle; 337 return 0; 338 } 339 340 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 341 struct gnet_dump *d) 342 { 343 struct multiq_sched_data *q = qdisc_priv(sch); 344 struct Qdisc *cl_q; 345 346 cl_q = q->queues[cl - 1]; 347 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), 348 d, NULL, &cl_q->bstats) < 0 || 349 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0) 350 return -1; 351 352 return 0; 353 } 354 355 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 356 { 357 struct multiq_sched_data *q = qdisc_priv(sch); 358 int band; 359 360 if (arg->stop) 361 return; 362 363 for (band = 0; band < q->bands; band++) { 364 if (arg->count < arg->skip) { 365 arg->count++; 366 continue; 367 } 368 if (arg->fn(sch, band + 1, arg) < 0) { 369 arg->stop = 1; 370 break; 371 } 372 arg->count++; 373 } 374 } 375 376 static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl) 377 { 378 struct multiq_sched_data *q = qdisc_priv(sch); 379 380 if (cl) 381 return NULL; 382 return q->block; 383 } 384 385 static const struct Qdisc_class_ops multiq_class_ops = { 386 .graft = multiq_graft, 387 .leaf = multiq_leaf, 388 .get = multiq_get, 389 .put = multiq_put, 390 .walk = multiq_walk, 391 .tcf_block = multiq_tcf_block, 392 .bind_tcf = multiq_bind, 393 .unbind_tcf = multiq_put, 394 .dump = multiq_dump_class, 395 .dump_stats = multiq_dump_class_stats, 396 }; 397 398 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 399 .next = NULL, 400 .cl_ops = &multiq_class_ops, 401 .id = "multiq", 402 .priv_size = sizeof(struct multiq_sched_data), 403 .enqueue = multiq_enqueue, 404 .dequeue = multiq_dequeue, 405 .peek = multiq_peek, 406 .init = multiq_init, 407 .reset = multiq_reset, 408 .destroy = multiq_destroy, 409 .change = multiq_tune, 410 .dump = multiq_dump, 411 .owner = THIS_MODULE, 412 }; 413 414 static int __init multiq_module_init(void) 415 { 416 return register_qdisc(&multiq_qdisc_ops); 417 } 418 419 static void __exit multiq_module_exit(void) 420 { 421 unregister_qdisc(&multiq_qdisc_ops); 422 } 423 424 module_init(multiq_module_init) 425 module_exit(multiq_module_exit) 426 427 MODULE_LICENSE("GPL"); 428