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 /* fall through */ 58 case TC_ACT_SHOT: 59 return NULL; 60 } 61 #endif 62 band = skb_get_queue_mapping(skb); 63 64 if (band >= q->bands) 65 return q->queues[0]; 66 67 return q->queues[band]; 68 } 69 70 static int 71 multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 72 struct sk_buff **to_free) 73 { 74 struct Qdisc *qdisc; 75 int ret; 76 77 qdisc = multiq_classify(skb, sch, &ret); 78 #ifdef CONFIG_NET_CLS_ACT 79 if (qdisc == NULL) { 80 81 if (ret & __NET_XMIT_BYPASS) 82 qdisc_qstats_drop(sch); 83 __qdisc_drop(skb, to_free); 84 return ret; 85 } 86 #endif 87 88 ret = qdisc_enqueue(skb, qdisc, to_free); 89 if (ret == NET_XMIT_SUCCESS) { 90 sch->q.qlen++; 91 return NET_XMIT_SUCCESS; 92 } 93 if (net_xmit_drop_count(ret)) 94 qdisc_qstats_drop(sch); 95 return ret; 96 } 97 98 static struct sk_buff *multiq_dequeue(struct Qdisc *sch) 99 { 100 struct multiq_sched_data *q = qdisc_priv(sch); 101 struct Qdisc *qdisc; 102 struct sk_buff *skb; 103 int band; 104 105 for (band = 0; band < q->bands; band++) { 106 /* cycle through bands to ensure fairness */ 107 q->curband++; 108 if (q->curband >= q->bands) 109 q->curband = 0; 110 111 /* Check that target subqueue is available before 112 * pulling an skb to avoid head-of-line blocking. 113 */ 114 if (!netif_xmit_stopped( 115 netdev_get_tx_queue(qdisc_dev(sch), q->curband))) { 116 qdisc = q->queues[q->curband]; 117 skb = qdisc->dequeue(qdisc); 118 if (skb) { 119 qdisc_bstats_update(sch, skb); 120 sch->q.qlen--; 121 return skb; 122 } 123 } 124 } 125 return NULL; 126 127 } 128 129 static struct sk_buff *multiq_peek(struct Qdisc *sch) 130 { 131 struct multiq_sched_data *q = qdisc_priv(sch); 132 unsigned int curband = q->curband; 133 struct Qdisc *qdisc; 134 struct sk_buff *skb; 135 int band; 136 137 for (band = 0; band < q->bands; band++) { 138 /* cycle through bands to ensure fairness */ 139 curband++; 140 if (curband >= q->bands) 141 curband = 0; 142 143 /* Check that target subqueue is available before 144 * pulling an skb to avoid head-of-line blocking. 145 */ 146 if (!netif_xmit_stopped( 147 netdev_get_tx_queue(qdisc_dev(sch), curband))) { 148 qdisc = q->queues[curband]; 149 skb = qdisc->ops->peek(qdisc); 150 if (skb) 151 return skb; 152 } 153 } 154 return NULL; 155 156 } 157 158 static void 159 multiq_reset(struct Qdisc *sch) 160 { 161 u16 band; 162 struct multiq_sched_data *q = qdisc_priv(sch); 163 164 for (band = 0; band < q->bands; band++) 165 qdisc_reset(q->queues[band]); 166 sch->q.qlen = 0; 167 q->curband = 0; 168 } 169 170 static void 171 multiq_destroy(struct Qdisc *sch) 172 { 173 int band; 174 struct multiq_sched_data *q = qdisc_priv(sch); 175 176 tcf_block_put(q->block); 177 for (band = 0; band < q->bands; band++) 178 qdisc_put(q->queues[band]); 179 180 kfree(q->queues); 181 } 182 183 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt, 184 struct netlink_ext_ack *extack) 185 { 186 struct multiq_sched_data *q = qdisc_priv(sch); 187 struct tc_multiq_qopt *qopt; 188 int i; 189 190 if (!netif_is_multiqueue(qdisc_dev(sch))) 191 return -EOPNOTSUPP; 192 if (nla_len(opt) < sizeof(*qopt)) 193 return -EINVAL; 194 195 qopt = nla_data(opt); 196 197 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 198 199 sch_tree_lock(sch); 200 q->bands = qopt->bands; 201 for (i = q->bands; i < q->max_bands; i++) { 202 if (q->queues[i] != &noop_qdisc) { 203 struct Qdisc *child = q->queues[i]; 204 q->queues[i] = &noop_qdisc; 205 qdisc_tree_reduce_backlog(child, child->q.qlen, 206 child->qstats.backlog); 207 qdisc_put(child); 208 } 209 } 210 211 sch_tree_unlock(sch); 212 213 for (i = 0; i < q->bands; i++) { 214 if (q->queues[i] == &noop_qdisc) { 215 struct Qdisc *child, *old; 216 child = qdisc_create_dflt(sch->dev_queue, 217 &pfifo_qdisc_ops, 218 TC_H_MAKE(sch->handle, 219 i + 1), extack); 220 if (child) { 221 sch_tree_lock(sch); 222 old = q->queues[i]; 223 q->queues[i] = child; 224 if (child != &noop_qdisc) 225 qdisc_hash_add(child, true); 226 227 if (old != &noop_qdisc) { 228 qdisc_tree_reduce_backlog(old, 229 old->q.qlen, 230 old->qstats.backlog); 231 qdisc_put(old); 232 } 233 sch_tree_unlock(sch); 234 } 235 } 236 } 237 return 0; 238 } 239 240 static int multiq_init(struct Qdisc *sch, struct nlattr *opt, 241 struct netlink_ext_ack *extack) 242 { 243 struct multiq_sched_data *q = qdisc_priv(sch); 244 int i, err; 245 246 q->queues = NULL; 247 248 if (!opt) 249 return -EINVAL; 250 251 err = tcf_block_get(&q->block, &q->filter_list, sch, extack); 252 if (err) 253 return err; 254 255 q->max_bands = qdisc_dev(sch)->num_tx_queues; 256 257 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 258 if (!q->queues) 259 return -ENOBUFS; 260 for (i = 0; i < q->max_bands; i++) 261 q->queues[i] = &noop_qdisc; 262 263 return multiq_tune(sch, opt, extack); 264 } 265 266 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 267 { 268 struct multiq_sched_data *q = qdisc_priv(sch); 269 unsigned char *b = skb_tail_pointer(skb); 270 struct tc_multiq_qopt opt; 271 272 opt.bands = q->bands; 273 opt.max_bands = q->max_bands; 274 275 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 276 goto nla_put_failure; 277 278 return skb->len; 279 280 nla_put_failure: 281 nlmsg_trim(skb, b); 282 return -1; 283 } 284 285 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 286 struct Qdisc **old, struct netlink_ext_ack *extack) 287 { 288 struct multiq_sched_data *q = qdisc_priv(sch); 289 unsigned long band = arg - 1; 290 291 if (new == NULL) 292 new = &noop_qdisc; 293 294 *old = qdisc_replace(sch, new, &q->queues[band]); 295 return 0; 296 } 297 298 static struct Qdisc * 299 multiq_leaf(struct Qdisc *sch, unsigned long arg) 300 { 301 struct multiq_sched_data *q = qdisc_priv(sch); 302 unsigned long band = arg - 1; 303 304 return q->queues[band]; 305 } 306 307 static unsigned long multiq_find(struct Qdisc *sch, u32 classid) 308 { 309 struct multiq_sched_data *q = qdisc_priv(sch); 310 unsigned long band = TC_H_MIN(classid); 311 312 if (band - 1 >= q->bands) 313 return 0; 314 return band; 315 } 316 317 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 318 u32 classid) 319 { 320 return multiq_find(sch, classid); 321 } 322 323 324 static void multiq_unbind(struct Qdisc *q, unsigned long cl) 325 { 326 } 327 328 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 329 struct sk_buff *skb, struct tcmsg *tcm) 330 { 331 struct multiq_sched_data *q = qdisc_priv(sch); 332 333 tcm->tcm_handle |= TC_H_MIN(cl); 334 tcm->tcm_info = q->queues[cl - 1]->handle; 335 return 0; 336 } 337 338 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 339 struct gnet_dump *d) 340 { 341 struct multiq_sched_data *q = qdisc_priv(sch); 342 struct Qdisc *cl_q; 343 344 cl_q = q->queues[cl - 1]; 345 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), 346 d, NULL, &cl_q->bstats) < 0 || 347 gnet_stats_copy_queue(d, NULL, &cl_q->qstats, cl_q->q.qlen) < 0) 348 return -1; 349 350 return 0; 351 } 352 353 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 354 { 355 struct multiq_sched_data *q = qdisc_priv(sch); 356 int band; 357 358 if (arg->stop) 359 return; 360 361 for (band = 0; band < q->bands; band++) { 362 if (arg->count < arg->skip) { 363 arg->count++; 364 continue; 365 } 366 if (arg->fn(sch, band + 1, arg) < 0) { 367 arg->stop = 1; 368 break; 369 } 370 arg->count++; 371 } 372 } 373 374 static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl, 375 struct netlink_ext_ack *extack) 376 { 377 struct multiq_sched_data *q = qdisc_priv(sch); 378 379 if (cl) 380 return NULL; 381 return q->block; 382 } 383 384 static const struct Qdisc_class_ops multiq_class_ops = { 385 .graft = multiq_graft, 386 .leaf = multiq_leaf, 387 .find = multiq_find, 388 .walk = multiq_walk, 389 .tcf_block = multiq_tcf_block, 390 .bind_tcf = multiq_bind, 391 .unbind_tcf = multiq_unbind, 392 .dump = multiq_dump_class, 393 .dump_stats = multiq_dump_class_stats, 394 }; 395 396 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 397 .next = NULL, 398 .cl_ops = &multiq_class_ops, 399 .id = "multiq", 400 .priv_size = sizeof(struct multiq_sched_data), 401 .enqueue = multiq_enqueue, 402 .dequeue = multiq_dequeue, 403 .peek = multiq_peek, 404 .init = multiq_init, 405 .reset = multiq_reset, 406 .destroy = multiq_destroy, 407 .change = multiq_tune, 408 .dump = multiq_dump, 409 .owner = THIS_MODULE, 410 }; 411 412 static int __init multiq_module_init(void) 413 { 414 return register_qdisc(&multiq_qdisc_ops); 415 } 416 417 static void __exit multiq_module_exit(void) 418 { 419 unregister_qdisc(&multiq_qdisc_ops); 420 } 421 422 module_init(multiq_module_init) 423 module_exit(multiq_module_exit) 424 425 MODULE_LICENSE("GPL"); 426