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, NULL, 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 q->curband = 0; 156 } 157 158 static void 159 multiq_destroy(struct Qdisc *sch) 160 { 161 int band; 162 struct multiq_sched_data *q = qdisc_priv(sch); 163 164 tcf_block_put(q->block); 165 for (band = 0; band < q->bands; band++) 166 qdisc_put(q->queues[band]); 167 168 kfree(q->queues); 169 } 170 171 static int multiq_tune(struct Qdisc *sch, struct nlattr *opt, 172 struct netlink_ext_ack *extack) 173 { 174 struct multiq_sched_data *q = qdisc_priv(sch); 175 struct tc_multiq_qopt *qopt; 176 struct Qdisc **removed; 177 int i, n_removed = 0; 178 179 if (!netif_is_multiqueue(qdisc_dev(sch))) 180 return -EOPNOTSUPP; 181 if (nla_len(opt) < sizeof(*qopt)) 182 return -EINVAL; 183 184 qopt = nla_data(opt); 185 186 qopt->bands = qdisc_dev(sch)->real_num_tx_queues; 187 188 removed = kmalloc(sizeof(*removed) * (q->max_bands - q->bands), 189 GFP_KERNEL); 190 if (!removed) 191 return -ENOMEM; 192 193 sch_tree_lock(sch); 194 q->bands = qopt->bands; 195 for (i = q->bands; i < q->max_bands; i++) { 196 if (q->queues[i] != &noop_qdisc) { 197 struct Qdisc *child = q->queues[i]; 198 199 q->queues[i] = &noop_qdisc; 200 qdisc_purge_queue(child); 201 removed[n_removed++] = child; 202 } 203 } 204 205 sch_tree_unlock(sch); 206 207 for (i = 0; i < n_removed; i++) 208 qdisc_put(removed[i]); 209 kfree(removed); 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), extack); 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_purge_queue(old); 227 sch_tree_unlock(sch); 228 qdisc_put(old); 229 } 230 } 231 } 232 return 0; 233 } 234 235 static int multiq_init(struct Qdisc *sch, struct nlattr *opt, 236 struct netlink_ext_ack *extack) 237 { 238 struct multiq_sched_data *q = qdisc_priv(sch); 239 int i, err; 240 241 q->queues = NULL; 242 243 if (!opt) 244 return -EINVAL; 245 246 err = tcf_block_get(&q->block, &q->filter_list, sch, extack); 247 if (err) 248 return err; 249 250 q->max_bands = qdisc_dev(sch)->num_tx_queues; 251 252 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL); 253 if (!q->queues) 254 return -ENOBUFS; 255 for (i = 0; i < q->max_bands; i++) 256 q->queues[i] = &noop_qdisc; 257 258 return multiq_tune(sch, opt, extack); 259 } 260 261 static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb) 262 { 263 struct multiq_sched_data *q = qdisc_priv(sch); 264 unsigned char *b = skb_tail_pointer(skb); 265 struct tc_multiq_qopt opt; 266 267 opt.bands = q->bands; 268 opt.max_bands = q->max_bands; 269 270 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 271 goto nla_put_failure; 272 273 return skb->len; 274 275 nla_put_failure: 276 nlmsg_trim(skb, b); 277 return -1; 278 } 279 280 static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 281 struct Qdisc **old, struct netlink_ext_ack *extack) 282 { 283 struct multiq_sched_data *q = qdisc_priv(sch); 284 unsigned long band = arg - 1; 285 286 if (new == NULL) 287 new = &noop_qdisc; 288 289 *old = qdisc_replace(sch, new, &q->queues[band]); 290 return 0; 291 } 292 293 static struct Qdisc * 294 multiq_leaf(struct Qdisc *sch, unsigned long arg) 295 { 296 struct multiq_sched_data *q = qdisc_priv(sch); 297 unsigned long band = arg - 1; 298 299 return q->queues[band]; 300 } 301 302 static unsigned long multiq_find(struct Qdisc *sch, u32 classid) 303 { 304 struct multiq_sched_data *q = qdisc_priv(sch); 305 unsigned long band = TC_H_MIN(classid); 306 307 if (band - 1 >= q->bands) 308 return 0; 309 return band; 310 } 311 312 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent, 313 u32 classid) 314 { 315 return multiq_find(sch, classid); 316 } 317 318 319 static void multiq_unbind(struct Qdisc *q, unsigned long cl) 320 { 321 } 322 323 static int multiq_dump_class(struct Qdisc *sch, unsigned long cl, 324 struct sk_buff *skb, struct tcmsg *tcm) 325 { 326 struct multiq_sched_data *q = qdisc_priv(sch); 327 328 tcm->tcm_handle |= TC_H_MIN(cl); 329 tcm->tcm_info = q->queues[cl - 1]->handle; 330 return 0; 331 } 332 333 static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl, 334 struct gnet_dump *d) 335 { 336 struct multiq_sched_data *q = qdisc_priv(sch); 337 struct Qdisc *cl_q; 338 339 cl_q = q->queues[cl - 1]; 340 if (gnet_stats_copy_basic(d, cl_q->cpu_bstats, &cl_q->bstats, true) < 0 || 341 qdisc_qstats_copy(d, cl_q) < 0) 342 return -1; 343 344 return 0; 345 } 346 347 static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 348 { 349 struct multiq_sched_data *q = qdisc_priv(sch); 350 int band; 351 352 if (arg->stop) 353 return; 354 355 for (band = 0; band < q->bands; band++) { 356 if (!tc_qdisc_stats_dump(sch, band + 1, arg)) 357 break; 358 } 359 } 360 361 static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl, 362 struct netlink_ext_ack *extack) 363 { 364 struct multiq_sched_data *q = qdisc_priv(sch); 365 366 if (cl) 367 return NULL; 368 return q->block; 369 } 370 371 static const struct Qdisc_class_ops multiq_class_ops = { 372 .graft = multiq_graft, 373 .leaf = multiq_leaf, 374 .find = multiq_find, 375 .walk = multiq_walk, 376 .tcf_block = multiq_tcf_block, 377 .bind_tcf = multiq_bind, 378 .unbind_tcf = multiq_unbind, 379 .dump = multiq_dump_class, 380 .dump_stats = multiq_dump_class_stats, 381 }; 382 383 static struct Qdisc_ops multiq_qdisc_ops __read_mostly = { 384 .next = NULL, 385 .cl_ops = &multiq_class_ops, 386 .id = "multiq", 387 .priv_size = sizeof(struct multiq_sched_data), 388 .enqueue = multiq_enqueue, 389 .dequeue = multiq_dequeue, 390 .peek = multiq_peek, 391 .init = multiq_init, 392 .reset = multiq_reset, 393 .destroy = multiq_destroy, 394 .change = multiq_tune, 395 .dump = multiq_dump, 396 .owner = THIS_MODULE, 397 }; 398 399 static int __init multiq_module_init(void) 400 { 401 return register_qdisc(&multiq_qdisc_ops); 402 } 403 404 static void __exit multiq_module_exit(void) 405 { 406 unregister_qdisc(&multiq_qdisc_ops); 407 } 408 409 module_init(multiq_module_init) 410 module_exit(multiq_module_exit) 411 412 MODULE_LICENSE("GPL"); 413