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, write to the Free Software Foundation, Inc., 59 Temple 15 * Place - Suite 330, Boston, MA 02111-1307 USA. 16 * 17 * Author: Alexander Duyck <alexander.h.duyck@intel.com> 18 */ 19 20 #include <linux/module.h> 21 #include <linux/slab.h> 22 #include <linux/types.h> 23 #include <linux/kernel.h> 24 #include <linux/string.h> 25 #include <linux/errno.h> 26 #include <linux/skbuff.h> 27 #include <net/netlink.h> 28 #include <net/pkt_sched.h> 29 30 31 struct multiq_sched_data { 32 u16 bands; 33 u16 max_bands; 34 u16 curband; 35 struct tcf_proto *filter_list; 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 int err; 47 48 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 49 err = tc_classify(skb, q->filter_list, &res); 50 #ifdef CONFIG_NET_CLS_ACT 51 switch (err) { 52 case TC_ACT_STOLEN: 53 case TC_ACT_QUEUED: 54 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 55 case TC_ACT_SHOT: 56 return NULL; 57 } 58 #endif 59 band = skb_get_queue_mapping(skb); 60 61 if (band >= q->bands) 62 return q->queues[0]; 63 64 return q->queues[band]; 65 } 66 67 static int 68 multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch) 69 { 70 struct Qdisc *qdisc; 71 int ret; 72 73 qdisc = multiq_classify(skb, sch, &ret); 74 #ifdef CONFIG_NET_CLS_ACT 75 if (qdisc == NULL) { 76 77 if (ret & __NET_XMIT_BYPASS) 78 sch->qstats.drops++; 79 kfree_skb(skb); 80 return ret; 81 } 82 #endif 83 84 ret = qdisc_enqueue(skb, qdisc); 85 if (ret == NET_XMIT_SUCCESS) { 86 sch->q.qlen++; 87 return NET_XMIT_SUCCESS; 88 } 89 if (net_xmit_drop_count(ret)) 90 sch->qstats.drops++; 91 return ret; 92 } 93 94 static struct sk_buff *multiq_dequeue(struct Qdisc *sch) 95 { 96 struct multiq_sched_data *q = qdisc_priv(sch); 97 struct Qdisc *qdisc; 98 struct sk_buff *skb; 99 int band; 100 101 for (band = 0; band < q->bands; band++) { 102 /* cycle through bands to ensure fairness */ 103 q->curband++; 104 if (q->curband >= q->bands) 105 q->curband = 0; 106 107 /* Check that target subqueue is available before 108 * pulling an skb to avoid head-of-line blocking. 109 */ 110 if (!__netif_subqueue_stopped(qdisc_dev(sch), q->curband)) { 111 qdisc = q->queues[q->curband]; 112 skb = qdisc->dequeue(qdisc); 113 if (skb) { 114 qdisc_bstats_update(sch, skb); 115 sch->q.qlen--; 116 return skb; 117 } 118 } 119 } 120 return NULL; 121 122 } 123 124 static struct sk_buff *multiq_peek(struct Qdisc *sch) 125 { 126 struct multiq_sched_data *q = qdisc_priv(sch); 127 unsigned int curband = q->curband; 128 struct Qdisc *qdisc; 129 struct sk_buff *skb; 130 int band; 131 132 for (band = 0; band < q->bands; band++) { 133 /* cycle through bands to ensure fairness */ 134 curband++; 135 if (curband >= q->bands) 136 curband = 0; 137 138 /* Check that target subqueue is available before 139 * pulling an skb to avoid head-of-line blocking. 140 */ 141 if (!__netif_subqueue_stopped(qdisc_dev(sch), curband)) { 142 qdisc = q->queues[curband]; 143 skb = qdisc->ops->peek(qdisc); 144 if (skb) 145 return skb; 146 } 147 } 148 return NULL; 149 150 } 151 152 static unsigned int multiq_drop(struct Qdisc *sch) 153 { 154 struct multiq_sched_data *q = qdisc_priv(sch); 155 int band; 156 unsigned int len; 157 struct Qdisc *qdisc; 158 159 for (band = q->bands - 1; band >= 0; band--) { 160 qdisc = q->queues[band]; 161 if (qdisc->ops->drop) { 162 len = qdisc->ops->drop(qdisc); 163 if (len != 0) { 164 sch->q.qlen--; 165 return len; 166 } 167 } 168 } 169 return 0; 170 } 171 172 173 static void 174 multiq_reset(struct Qdisc *sch) 175 { 176 u16 band; 177 struct multiq_sched_data *q = qdisc_priv(sch); 178 179 for (band = 0; band < q->bands; band++) 180 qdisc_reset(q->queues[band]); 181 sch->q.qlen = 0; 182 q->curband = 0; 183 } 184 185 static void 186 multiq_destroy(struct Qdisc *sch) 187 { 188 int band; 189 struct multiq_sched_data *q = qdisc_priv(sch); 190 191 tcf_destroy_chain(&q->filter_list); 192 for (band = 0; band < q->bands; band++) 193 qdisc_destroy(q->queues[band]); 194 195 kfree(q->queues); 196 } 197 198 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) 199 { 200 struct multiq_sched_data *q = qdisc_priv(sch); 201 struct tc_multiq_qopt *qopt; 202 int i; 203 204 if (!netif_is_multiqueue(qdisc_dev(sch))) 205 return -EOPNOTSUPP; 206 if (nla_len(opt) < sizeof(*qopt)) 207 return -EINVAL; 208 209 qopt = nla_data(opt); 210 211 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 212 213 sch_tree_lock(sch); 214 q->bands = qopt->bands; 215 for (i = q->bands; i < q->max_bands; i++) { 216 if (q->queues[i] != &noop_qdisc) { 217 struct Qdisc *child = q->queues[i]; 218 q->queues[i] = &noop_qdisc; 219 qdisc_tree_decrease_qlen(child, child->q.qlen); 220 qdisc_destroy(child); 221 } 222 } 223 224 sch_tree_unlock(sch); 225 226 for (i = 0; i < q->bands; i++) { 227 if (q->queues[i] == &noop_qdisc) { 228 struct Qdisc *child, *old; 229 child = qdisc_create_dflt(sch->dev_queue, 230 &pfifo_qdisc_ops, 231 TC_H_MAKE(sch->handle, 232 i + 1)); 233 if (child) { 234 sch_tree_lock(sch); 235 old = q->queues[i]; 236 q->queues[i] = child; 237 238 if (old != &noop_qdisc) { 239 qdisc_tree_decrease_qlen(old, 240 old->q.qlen); 241 qdisc_destroy(old); 242 } 243 sch_tree_unlock(sch); 244 } 245 } 246 } 247 return 0; 248 } 249 250 static int multiq_init(struct Qdisc *sch, struct nlattr *opt) 251 { 252 struct multiq_sched_data *q = qdisc_priv(sch); 253 int i, err; 254 255 q->queues = NULL; 256 257 if (opt == NULL) 258 return -EINVAL; 259 260 q->max_bands = qdisc_dev(sch)->num_tx_queues; 261 262 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 263 if (!q->queues) 264 return -ENOBUFS; 265 for (i = 0; i < q->max_bands; i++) 266 q->queues[i] = &noop_qdisc; 267 268 err = multiq_tune(sch, opt); 269 270 if (err) 271 kfree(q->queues); 272 273 return err; 274 } 275 276 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 277 { 278 struct multiq_sched_data *q = qdisc_priv(sch); 279 unsigned char *b = skb_tail_pointer(skb); 280 struct tc_multiq_qopt opt; 281 282 opt.bands = q->bands; 283 opt.max_bands = q->max_bands; 284 285 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); 286 287 return skb->len; 288 289 nla_put_failure: 290 nlmsg_trim(skb, b); 291 return -1; 292 } 293 294 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 295 struct Qdisc **old) 296 { 297 struct multiq_sched_data *q = qdisc_priv(sch); 298 unsigned long band = arg - 1; 299 300 if (new == NULL) 301 new = &noop_qdisc; 302 303 sch_tree_lock(sch); 304 *old = q->queues[band]; 305 q->queues[band] = new; 306 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); 307 qdisc_reset(*old); 308 sch_tree_unlock(sch); 309 310 return 0; 311 } 312 313 static struct Qdisc * 314 multiq_leaf(struct Qdisc *sch, unsigned long arg) 315 { 316 struct multiq_sched_data *q = qdisc_priv(sch); 317 unsigned long band = arg - 1; 318 319 return q->queues[band]; 320 } 321 322 static unsigned long multiq_get(struct Qdisc *sch, u32 classid) 323 { 324 struct multiq_sched_data *q = qdisc_priv(sch); 325 unsigned long band = TC_H_MIN(classid); 326 327 if (band - 1 >= q->bands) 328 return 0; 329 return band; 330 } 331 332 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 333 u32 classid) 334 { 335 return multiq_get(sch, classid); 336 } 337 338 339 static void multiq_put(struct Qdisc *q, unsigned long cl) 340 { 341 } 342 343 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 344 struct sk_buff *skb, struct tcmsg *tcm) 345 { 346 struct multiq_sched_data *q = qdisc_priv(sch); 347 348 tcm->tcm_handle |= TC_H_MIN(cl); 349 tcm->tcm_info = q->queues[cl - 1]->handle; 350 return 0; 351 } 352 353 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 354 struct gnet_dump *d) 355 { 356 struct multiq_sched_data *q = qdisc_priv(sch); 357 struct Qdisc *cl_q; 358 359 cl_q = q->queues[cl - 1]; 360 cl_q->qstats.qlen = cl_q->q.qlen; 361 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || 362 gnet_stats_copy_queue(d, &cl_q->qstats) < 0) 363 return -1; 364 365 return 0; 366 } 367 368 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 369 { 370 struct multiq_sched_data *q = qdisc_priv(sch); 371 int band; 372 373 if (arg->stop) 374 return; 375 376 for (band = 0; band < q->bands; band++) { 377 if (arg->count < arg->skip) { 378 arg->count++; 379 continue; 380 } 381 if (arg->fn(sch, band + 1, arg) < 0) { 382 arg->stop = 1; 383 break; 384 } 385 arg->count++; 386 } 387 } 388 389 static struct tcf_proto **multiq_find_tcf(struct Qdisc *sch, unsigned long cl) 390 { 391 struct multiq_sched_data *q = qdisc_priv(sch); 392 393 if (cl) 394 return NULL; 395 return &q->filter_list; 396 } 397 398 static const struct Qdisc_class_ops multiq_class_ops = { 399 .graft = multiq_graft, 400 .leaf = multiq_leaf, 401 .get = multiq_get, 402 .put = multiq_put, 403 .walk = multiq_walk, 404 .tcf_chain = multiq_find_tcf, 405 .bind_tcf = multiq_bind, 406 .unbind_tcf = multiq_put, 407 .dump = multiq_dump_class, 408 .dump_stats = multiq_dump_class_stats, 409 }; 410 411 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 412 .next = NULL, 413 .cl_ops = &multiq_class_ops, 414 .id = "multiq", 415 .priv_size = sizeof(struct multiq_sched_data), 416 .enqueue = multiq_enqueue, 417 .dequeue = multiq_dequeue, 418 .peek = multiq_peek, 419 .drop = multiq_drop, 420 .init = multiq_init, 421 .reset = multiq_reset, 422 .destroy = multiq_destroy, 423 .change = multiq_tune, 424 .dump = multiq_dump, 425 .owner = THIS_MODULE, 426 }; 427 428 static int __init multiq_module_init(void) 429 { 430 return register_qdisc(&multiq_qdisc_ops); 431 } 432 433 static void __exit multiq_module_exit(void) 434 { 435 unregister_qdisc(&multiq_qdisc_ops); 436 } 437 438 module_init(multiq_module_init) 439 module_exit(multiq_module_exit) 440 441 MODULE_LICENSE("GPL"); 442