1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, Intel Corporation. 4 * 5 * Author: Alexander Duyck <alexander.h.duyck@intel.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/slab.h> 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/string.h> 13 #include <linux/errno.h> 14 #include <linux/skbuff.h> 15 #include <net/netlink.h> 16 #include <net/pkt_sched.h> 17 #include <net/pkt_cls.h> 18 19 struct multiq_sched_data { 20 u16 bands; 21 u16 max_bands; 22 u16 curband; 23 struct tcf_proto __rcu *filter_list; 24 struct tcf_block *block; 25 struct Qdisc **queues; 26 }; 27 28 29 static struct Qdisc * 30 multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) 31 { 32 struct multiq_sched_data *q = qdisc_priv(sch); 33 u32 band; 34 struct tcf_result res; 35 struct tcf_proto *fl = rcu_dereference_bh(q->filter_list); 36 int err; 37 38 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 39 err = tcf_classify(skb, fl, &res, false); 40 #ifdef CONFIG_NET_CLS_ACT 41 switch (err) { 42 case TC_ACT_STOLEN: 43 case TC_ACT_QUEUED: 44 case TC_ACT_TRAP: 45 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 46 fallthrough; 47 case TC_ACT_SHOT: 48 return NULL; 49 } 50 #endif 51 band = skb_get_queue_mapping(skb); 52 53 if (band >= q->bands) 54 return q->queues[0]; 55 56 return q->queues[band]; 57 } 58 59 static int 60 multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 61 struct sk_buff **to_free) 62 { 63 struct Qdisc *qdisc; 64 int ret; 65 66 qdisc = multiq_classify(skb, sch, &ret); 67 #ifdef CONFIG_NET_CLS_ACT 68 if (qdisc == NULL) { 69 70 if (ret & __NET_XMIT_BYPASS) 71 qdisc_qstats_drop(sch); 72 __qdisc_drop(skb, to_free); 73 return ret; 74 } 75 #endif 76 77 ret = qdisc_enqueue(skb, qdisc, to_free); 78 if (ret == NET_XMIT_SUCCESS) { 79 sch->q.qlen++; 80 return NET_XMIT_SUCCESS; 81 } 82 if (net_xmit_drop_count(ret)) 83 qdisc_qstats_drop(sch); 84 return ret; 85 } 86 87 static struct sk_buff *multiq_dequeue(struct Qdisc *sch) 88 { 89 struct multiq_sched_data *q = qdisc_priv(sch); 90 struct Qdisc *qdisc; 91 struct sk_buff *skb; 92 int band; 93 94 for (band = 0; band < q->bands; band++) { 95 /* cycle through bands to ensure fairness */ 96 q->curband++; 97 if (q->curband >= q->bands) 98 q->curband = 0; 99 100 /* Check that target subqueue is available before 101 * pulling an skb to avoid head-of-line blocking. 102 */ 103 if (!netif_xmit_stopped( 104 netdev_get_tx_queue(qdisc_dev(sch), q->curband))) { 105 qdisc = q->queues[q->curband]; 106 skb = qdisc->dequeue(qdisc); 107 if (skb) { 108 qdisc_bstats_update(sch, skb); 109 sch->q.qlen--; 110 return skb; 111 } 112 } 113 } 114 return NULL; 115 116 } 117 118 static struct sk_buff *multiq_peek(struct Qdisc *sch) 119 { 120 struct multiq_sched_data *q = qdisc_priv(sch); 121 unsigned int curband = q->curband; 122 struct Qdisc *qdisc; 123 struct sk_buff *skb; 124 int band; 125 126 for (band = 0; band < q->bands; band++) { 127 /* cycle through bands to ensure fairness */ 128 curband++; 129 if (curband >= q->bands) 130 curband = 0; 131 132 /* Check that target subqueue is available before 133 * pulling an skb to avoid head-of-line blocking. 134 */ 135 if (!netif_xmit_stopped( 136 netdev_get_tx_queue(qdisc_dev(sch), curband))) { 137 qdisc = q->queues[curband]; 138 skb = qdisc->ops->peek(qdisc); 139 if (skb) 140 return skb; 141 } 142 } 143 return NULL; 144 145 } 146 147 static void 148 multiq_reset(struct Qdisc *sch) 149 { 150 u16 band; 151 struct multiq_sched_data *q = qdisc_priv(sch); 152 153 for (band = 0; band < q->bands; band++) 154 qdisc_reset(q->queues[band]); 155 sch->q.qlen = 0; 156 q->curband = 0; 157 } 158 159 static void 160 multiq_destroy(struct Qdisc *sch) 161 { 162 int band; 163 struct multiq_sched_data *q = qdisc_priv(sch); 164 165 tcf_block_put(q->block); 166 for (band = 0; band < q->bands; band++) 167 qdisc_put(q->queues[band]); 168 169 kfree(q->queues); 170 } 171 172 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt, 173 struct netlink_ext_ack *extack) 174 { 175 struct multiq_sched_data *q = qdisc_priv(sch); 176 struct tc_multiq_qopt *qopt; 177 struct Qdisc **removed; 178 int i, n_removed = 0; 179 180 if (!netif_is_multiqueue(qdisc_dev(sch))) 181 return -EOPNOTSUPP; 182 if (nla_len(opt) < sizeof(*qopt)) 183 return -EINVAL; 184 185 qopt = nla_data(opt); 186 187 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 188 189 removed = kmalloc(sizeof(*removed) * (q->max_bands - q->bands), 190 GFP_KERNEL); 191 if (!removed) 192 return -ENOMEM; 193 194 sch_tree_lock(sch); 195 q->bands = qopt->bands; 196 for (i = q->bands; i < q->max_bands; i++) { 197 if (q->queues[i] != &noop_qdisc) { 198 struct Qdisc *child = q->queues[i]; 199 200 q->queues[i] = &noop_qdisc; 201 qdisc_purge_queue(child); 202 removed[n_removed++] = child; 203 } 204 } 205 206 sch_tree_unlock(sch); 207 208 for (i = 0; i < n_removed; i++) 209 qdisc_put(removed[i]); 210 kfree(removed); 211 212 for (i = 0; i < q->bands; i++) { 213 if (q->queues[i] == &noop_qdisc) { 214 struct Qdisc *child, *old; 215 child = qdisc_create_dflt(sch->dev_queue, 216 &pfifo_qdisc_ops, 217 TC_H_MAKE(sch->handle, 218 i + 1), extack); 219 if (child) { 220 sch_tree_lock(sch); 221 old = q->queues[i]; 222 q->queues[i] = child; 223 if (child != &noop_qdisc) 224 qdisc_hash_add(child, true); 225 226 if (old != &noop_qdisc) 227 qdisc_purge_queue(old); 228 sch_tree_unlock(sch); 229 qdisc_put(old); 230 } 231 } 232 } 233 return 0; 234 } 235 236 static int multiq_init(struct Qdisc *sch, struct nlattr *opt, 237 struct netlink_ext_ack *extack) 238 { 239 struct multiq_sched_data *q = qdisc_priv(sch); 240 int i, err; 241 242 q->queues = NULL; 243 244 if (!opt) 245 return -EINVAL; 246 247 err = tcf_block_get(&q->block, &q->filter_list, sch, extack); 248 if (err) 249 return err; 250 251 q->max_bands = qdisc_dev(sch)->num_tx_queues; 252 253 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 254 if (!q->queues) 255 return -ENOBUFS; 256 for (i = 0; i < q->max_bands; i++) 257 q->queues[i] = &noop_qdisc; 258 259 return multiq_tune(sch, opt, extack); 260 } 261 262 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 263 { 264 struct multiq_sched_data *q = qdisc_priv(sch); 265 unsigned char *b = skb_tail_pointer(skb); 266 struct tc_multiq_qopt opt; 267 268 opt.bands = q->bands; 269 opt.max_bands = q->max_bands; 270 271 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 272 goto nla_put_failure; 273 274 return skb->len; 275 276 nla_put_failure: 277 nlmsg_trim(skb, b); 278 return -1; 279 } 280 281 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 282 struct Qdisc **old, struct netlink_ext_ack *extack) 283 { 284 struct multiq_sched_data *q = qdisc_priv(sch); 285 unsigned long band = arg - 1; 286 287 if (new == NULL) 288 new = &noop_qdisc; 289 290 *old = qdisc_replace(sch, new, &q->queues[band]); 291 return 0; 292 } 293 294 static struct Qdisc * 295 multiq_leaf(struct Qdisc *sch, unsigned long arg) 296 { 297 struct multiq_sched_data *q = qdisc_priv(sch); 298 unsigned long band = arg - 1; 299 300 return q->queues[band]; 301 } 302 303 static unsigned long multiq_find(struct Qdisc *sch, u32 classid) 304 { 305 struct multiq_sched_data *q = qdisc_priv(sch); 306 unsigned long band = TC_H_MIN(classid); 307 308 if (band - 1 >= q->bands) 309 return 0; 310 return band; 311 } 312 313 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 314 u32 classid) 315 { 316 return multiq_find(sch, classid); 317 } 318 319 320 static void multiq_unbind(struct Qdisc *q, unsigned long cl) 321 { 322 } 323 324 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 325 struct sk_buff *skb, struct tcmsg *tcm) 326 { 327 struct multiq_sched_data *q = qdisc_priv(sch); 328 329 tcm->tcm_handle |= TC_H_MIN(cl); 330 tcm->tcm_info = q->queues[cl - 1]->handle; 331 return 0; 332 } 333 334 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 335 struct gnet_dump *d) 336 { 337 struct multiq_sched_data *q = qdisc_priv(sch); 338 struct Qdisc *cl_q; 339 340 cl_q = q->queues[cl - 1]; 341 if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), 342 d, cl_q->cpu_bstats, &cl_q->bstats) < 0 || 343 qdisc_qstats_copy(d, cl_q) < 0) 344 return -1; 345 346 return 0; 347 } 348 349 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 350 { 351 struct multiq_sched_data *q = qdisc_priv(sch); 352 int band; 353 354 if (arg->stop) 355 return; 356 357 for (band = 0; band < q->bands; band++) { 358 if (arg->count < arg->skip) { 359 arg->count++; 360 continue; 361 } 362 if (arg->fn(sch, band + 1, arg) < 0) { 363 arg->stop = 1; 364 break; 365 } 366 arg->count++; 367 } 368 } 369 370 static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl, 371 struct netlink_ext_ack *extack) 372 { 373 struct multiq_sched_data *q = qdisc_priv(sch); 374 375 if (cl) 376 return NULL; 377 return q->block; 378 } 379 380 static const struct Qdisc_class_ops multiq_class_ops = { 381 .graft = multiq_graft, 382 .leaf = multiq_leaf, 383 .find = multiq_find, 384 .walk = multiq_walk, 385 .tcf_block = multiq_tcf_block, 386 .bind_tcf = multiq_bind, 387 .unbind_tcf = multiq_unbind, 388 .dump = multiq_dump_class, 389 .dump_stats = multiq_dump_class_stats, 390 }; 391 392 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 393 .next = NULL, 394 .cl_ops = &multiq_class_ops, 395 .id = "multiq", 396 .priv_size = sizeof(struct multiq_sched_data), 397 .enqueue = multiq_enqueue, 398 .dequeue = multiq_dequeue, 399 .peek = multiq_peek, 400 .init = multiq_init, 401 .reset = multiq_reset, 402 .destroy = multiq_destroy, 403 .change = multiq_tune, 404 .dump = multiq_dump, 405 .owner = THIS_MODULE, 406 }; 407 408 static int __init multiq_module_init(void) 409 { 410 return register_qdisc(&multiq_qdisc_ops); 411 } 412 413 static void __exit multiq_module_exit(void) 414 { 415 unregister_qdisc(&multiq_qdisc_ops); 416 } 417 418 module_init(multiq_module_init) 419 module_exit(multiq_module_exit) 420 421 MODULE_LICENSE("GPL"); 422