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->bstats.bytes += qdisc_pkt_len(skb); 87 sch->bstats.packets++; 88 sch->q.qlen++; 89 return NET_XMIT_SUCCESS; 90 } 91 if (net_xmit_drop_count(ret)) 92 sch->qstats.drops++; 93 return ret; 94 } 95 96 static struct sk_buff *multiq_dequeue(struct Qdisc *sch) 97 { 98 struct multiq_sched_data *q = qdisc_priv(sch); 99 struct Qdisc *qdisc; 100 struct sk_buff *skb; 101 int band; 102 103 for (band = 0; band < q->bands; band++) { 104 /* cycle through bands to ensure fairness */ 105 q->curband++; 106 if (q->curband >= q->bands) 107 q->curband = 0; 108 109 /* Check that target subqueue is available before 110 * pulling an skb to avoid head-of-line blocking. 111 */ 112 if (!__netif_subqueue_stopped(qdisc_dev(sch), q->curband)) { 113 qdisc = q->queues[q->curband]; 114 skb = qdisc->dequeue(qdisc); 115 if (skb) { 116 sch->q.qlen--; 117 return skb; 118 } 119 } 120 } 121 return NULL; 122 123 } 124 125 static struct sk_buff *multiq_peek(struct Qdisc *sch) 126 { 127 struct multiq_sched_data *q = qdisc_priv(sch); 128 unsigned int curband = q->curband; 129 struct Qdisc *qdisc; 130 struct sk_buff *skb; 131 int band; 132 133 for (band = 0; band < q->bands; band++) { 134 /* cycle through bands to ensure fairness */ 135 curband++; 136 if (curband >= q->bands) 137 curband = 0; 138 139 /* Check that target subqueue is available before 140 * pulling an skb to avoid head-of-line blocking. 141 */ 142 if (!__netif_subqueue_stopped(qdisc_dev(sch), curband)) { 143 qdisc = q->queues[curband]; 144 skb = qdisc->ops->peek(qdisc); 145 if (skb) 146 return skb; 147 } 148 } 149 return NULL; 150 151 } 152 153 static unsigned int multiq_drop(struct Qdisc *sch) 154 { 155 struct multiq_sched_data *q = qdisc_priv(sch); 156 int band; 157 unsigned int len; 158 struct Qdisc *qdisc; 159 160 for (band = q->bands-1; band >= 0; band--) { 161 qdisc = q->queues[band]; 162 if (qdisc->ops->drop) { 163 len = qdisc->ops->drop(qdisc); 164 if (len != 0) { 165 sch->q.qlen--; 166 return len; 167 } 168 } 169 } 170 return 0; 171 } 172 173 174 static void 175 multiq_reset(struct Qdisc *sch) 176 { 177 u16 band; 178 struct multiq_sched_data *q = qdisc_priv(sch); 179 180 for (band = 0; band < q->bands; band++) 181 qdisc_reset(q->queues[band]); 182 sch->q.qlen = 0; 183 q->curband = 0; 184 } 185 186 static void 187 multiq_destroy(struct Qdisc *sch) 188 { 189 int band; 190 struct multiq_sched_data *q = qdisc_priv(sch); 191 192 tcf_destroy_chain(&q->filter_list); 193 for (band = 0; band < q->bands; band++) 194 qdisc_destroy(q->queues[band]); 195 196 kfree(q->queues); 197 } 198 199 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt) 200 { 201 struct multiq_sched_data *q = qdisc_priv(sch); 202 struct tc_multiq_qopt *qopt; 203 int i; 204 205 if (!netif_is_multiqueue(qdisc_dev(sch))) 206 return -EOPNOTSUPP; 207 if (nla_len(opt) < sizeof(*qopt)) 208 return -EINVAL; 209 210 qopt = nla_data(opt); 211 212 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 213 214 sch_tree_lock(sch); 215 q->bands = qopt->bands; 216 for (i = q->bands; i < q->max_bands; i++) { 217 if (q->queues[i] != &noop_qdisc) { 218 struct Qdisc *child = q->queues[i]; 219 q->queues[i] = &noop_qdisc; 220 qdisc_tree_decrease_qlen(child, child->q.qlen); 221 qdisc_destroy(child); 222 } 223 } 224 225 sch_tree_unlock(sch); 226 227 for (i = 0; i < q->bands; i++) { 228 if (q->queues[i] == &noop_qdisc) { 229 struct Qdisc *child, *old; 230 child = qdisc_create_dflt(sch->dev_queue, 231 &pfifo_qdisc_ops, 232 TC_H_MAKE(sch->handle, 233 i + 1)); 234 if (child) { 235 sch_tree_lock(sch); 236 old = q->queues[i]; 237 q->queues[i] = child; 238 239 if (old != &noop_qdisc) { 240 qdisc_tree_decrease_qlen(old, 241 old->q.qlen); 242 qdisc_destroy(old); 243 } 244 sch_tree_unlock(sch); 245 } 246 } 247 } 248 return 0; 249 } 250 251 static int multiq_init(struct Qdisc *sch, struct nlattr *opt) 252 { 253 struct multiq_sched_data *q = qdisc_priv(sch); 254 int i, err; 255 256 q->queues = NULL; 257 258 if (opt == NULL) 259 return -EINVAL; 260 261 q->max_bands = qdisc_dev(sch)->num_tx_queues; 262 263 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 264 if (!q->queues) 265 return -ENOBUFS; 266 for (i = 0; i < q->max_bands; i++) 267 q->queues[i] = &noop_qdisc; 268 269 err = multiq_tune(sch,opt); 270 271 if (err) 272 kfree(q->queues); 273 274 return err; 275 } 276 277 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 278 { 279 struct multiq_sched_data *q = qdisc_priv(sch); 280 unsigned char *b = skb_tail_pointer(skb); 281 struct tc_multiq_qopt opt; 282 283 opt.bands = q->bands; 284 opt.max_bands = q->max_bands; 285 286 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); 287 288 return skb->len; 289 290 nla_put_failure: 291 nlmsg_trim(skb, b); 292 return -1; 293 } 294 295 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 296 struct Qdisc **old) 297 { 298 struct multiq_sched_data *q = qdisc_priv(sch); 299 unsigned long band = arg - 1; 300 301 if (new == NULL) 302 new = &noop_qdisc; 303 304 sch_tree_lock(sch); 305 *old = q->queues[band]; 306 q->queues[band] = new; 307 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); 308 qdisc_reset(*old); 309 sch_tree_unlock(sch); 310 311 return 0; 312 } 313 314 static struct Qdisc * 315 multiq_leaf(struct Qdisc *sch, unsigned long arg) 316 { 317 struct multiq_sched_data *q = qdisc_priv(sch); 318 unsigned long band = arg - 1; 319 320 return q->queues[band]; 321 } 322 323 static unsigned long multiq_get(struct Qdisc *sch, u32 classid) 324 { 325 struct multiq_sched_data *q = qdisc_priv(sch); 326 unsigned long band = TC_H_MIN(classid); 327 328 if (band - 1 >= q->bands) 329 return 0; 330 return band; 331 } 332 333 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 334 u32 classid) 335 { 336 return multiq_get(sch, classid); 337 } 338 339 340 static void multiq_put(struct Qdisc *q, unsigned long cl) 341 { 342 } 343 344 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 345 struct sk_buff *skb, struct tcmsg *tcm) 346 { 347 struct multiq_sched_data *q = qdisc_priv(sch); 348 349 tcm->tcm_handle |= TC_H_MIN(cl); 350 tcm->tcm_info = q->queues[cl-1]->handle; 351 return 0; 352 } 353 354 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 355 struct gnet_dump *d) 356 { 357 struct multiq_sched_data *q = qdisc_priv(sch); 358 struct Qdisc *cl_q; 359 360 cl_q = q->queues[cl - 1]; 361 cl_q->qstats.qlen = cl_q->q.qlen; 362 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 || 363 gnet_stats_copy_queue(d, &cl_q->qstats) < 0) 364 return -1; 365 366 return 0; 367 } 368 369 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 370 { 371 struct multiq_sched_data *q = qdisc_priv(sch); 372 int band; 373 374 if (arg->stop) 375 return; 376 377 for (band = 0; band < q->bands; band++) { 378 if (arg->count < arg->skip) { 379 arg->count++; 380 continue; 381 } 382 if (arg->fn(sch, band+1, arg) < 0) { 383 arg->stop = 1; 384 break; 385 } 386 arg->count++; 387 } 388 } 389 390 static struct tcf_proto **multiq_find_tcf(struct Qdisc *sch, unsigned long cl) 391 { 392 struct multiq_sched_data *q = qdisc_priv(sch); 393 394 if (cl) 395 return NULL; 396 return &q->filter_list; 397 } 398 399 static const struct Qdisc_class_ops multiq_class_ops = { 400 .graft = multiq_graft, 401 .leaf = multiq_leaf, 402 .get = multiq_get, 403 .put = multiq_put, 404 .walk = multiq_walk, 405 .tcf_chain = multiq_find_tcf, 406 .bind_tcf = multiq_bind, 407 .unbind_tcf = multiq_put, 408 .dump = multiq_dump_class, 409 .dump_stats = multiq_dump_class_stats, 410 }; 411 412 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 413 .next = NULL, 414 .cl_ops = &multiq_class_ops, 415 .id = "multiq", 416 .priv_size = sizeof(struct multiq_sched_data), 417 .enqueue = multiq_enqueue, 418 .dequeue = multiq_dequeue, 419 .peek = multiq_peek, 420 .drop = multiq_drop, 421 .init = multiq_init, 422 .reset = multiq_reset, 423 .destroy = multiq_destroy, 424 .change = multiq_tune, 425 .dump = multiq_dump, 426 .owner = THIS_MODULE, 427 }; 428 429 static int __init multiq_module_init(void) 430 { 431 return register_qdisc(&multiq_qdisc_ops); 432 } 433 434 static void __exit multiq_module_exit(void) 435 { 436 unregister_qdisc(&multiq_qdisc_ops); 437 } 438 439 module_init(multiq_module_init) 440 module_exit(multiq_module_exit) 441 442 MODULE_LICENSE("GPL"); 443