1 /* 2 * net/sched/sch_mqprio.c 3 * 4 * Copyright (c) 2010 John Fastabend <john.r.fastabend@intel.com> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * version 2 as published by the Free Software Foundation. 9 */ 10 11 #include <linux/types.h> 12 #include <linux/slab.h> 13 #include <linux/kernel.h> 14 #include <linux/string.h> 15 #include <linux/errno.h> 16 #include <linux/skbuff.h> 17 #include <linux/module.h> 18 #include <net/netlink.h> 19 #include <net/pkt_sched.h> 20 #include <net/sch_generic.h> 21 22 struct mqprio_sched { 23 struct Qdisc **qdiscs; 24 int hw_owned; 25 }; 26 27 static void mqprio_destroy(struct Qdisc *sch) 28 { 29 struct net_device *dev = qdisc_dev(sch); 30 struct mqprio_sched *priv = qdisc_priv(sch); 31 unsigned int ntx; 32 33 if (priv->qdiscs) { 34 for (ntx = 0; 35 ntx < dev->num_tx_queues && priv->qdiscs[ntx]; 36 ntx++) 37 qdisc_destroy(priv->qdiscs[ntx]); 38 kfree(priv->qdiscs); 39 } 40 41 if (priv->hw_owned && dev->netdev_ops->ndo_setup_tc) 42 dev->netdev_ops->ndo_setup_tc(dev, 0); 43 else 44 netdev_set_num_tc(dev, 0); 45 } 46 47 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt) 48 { 49 int i, j; 50 51 /* Verify num_tc is not out of max range */ 52 if (qopt->num_tc > TC_MAX_QUEUE) 53 return -EINVAL; 54 55 /* Verify priority mapping uses valid tcs */ 56 for (i = 0; i < TC_BITMASK + 1; i++) { 57 if (qopt->prio_tc_map[i] >= qopt->num_tc) 58 return -EINVAL; 59 } 60 61 /* net_device does not support requested operation */ 62 if (qopt->hw && !dev->netdev_ops->ndo_setup_tc) 63 return -EINVAL; 64 65 /* if hw owned qcount and qoffset are taken from LLD so 66 * no reason to verify them here 67 */ 68 if (qopt->hw) 69 return 0; 70 71 for (i = 0; i < qopt->num_tc; i++) { 72 unsigned int last = qopt->offset[i] + qopt->count[i]; 73 74 /* Verify the queue count is in tx range being equal to the 75 * real_num_tx_queues indicates the last queue is in use. 76 */ 77 if (qopt->offset[i] >= dev->real_num_tx_queues || 78 !qopt->count[i] || 79 last > dev->real_num_tx_queues) 80 return -EINVAL; 81 82 /* Verify that the offset and counts do not overlap */ 83 for (j = i + 1; j < qopt->num_tc; j++) { 84 if (last > qopt->offset[j]) 85 return -EINVAL; 86 } 87 } 88 89 return 0; 90 } 91 92 static int mqprio_init(struct Qdisc *sch, struct nlattr *opt) 93 { 94 struct net_device *dev = qdisc_dev(sch); 95 struct mqprio_sched *priv = qdisc_priv(sch); 96 struct netdev_queue *dev_queue; 97 struct Qdisc *qdisc; 98 int i, err = -EOPNOTSUPP; 99 struct tc_mqprio_qopt *qopt = NULL; 100 101 BUILD_BUG_ON(TC_MAX_QUEUE != TC_QOPT_MAX_QUEUE); 102 BUILD_BUG_ON(TC_BITMASK != TC_QOPT_BITMASK); 103 104 if (sch->parent != TC_H_ROOT) 105 return -EOPNOTSUPP; 106 107 if (!netif_is_multiqueue(dev)) 108 return -EOPNOTSUPP; 109 110 if (!opt || nla_len(opt) < sizeof(*qopt)) 111 return -EINVAL; 112 113 qopt = nla_data(opt); 114 if (mqprio_parse_opt(dev, qopt)) 115 return -EINVAL; 116 117 /* pre-allocate qdisc, attachment can't fail */ 118 priv->qdiscs = kcalloc(dev->num_tx_queues, sizeof(priv->qdiscs[0]), 119 GFP_KERNEL); 120 if (priv->qdiscs == NULL) { 121 err = -ENOMEM; 122 goto err; 123 } 124 125 for (i = 0; i < dev->num_tx_queues; i++) { 126 dev_queue = netdev_get_tx_queue(dev, i); 127 qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops, 128 TC_H_MAKE(TC_H_MAJ(sch->handle), 129 TC_H_MIN(i + 1))); 130 if (qdisc == NULL) { 131 err = -ENOMEM; 132 goto err; 133 } 134 priv->qdiscs[i] = qdisc; 135 qdisc->flags |= TCQ_F_ONETXQUEUE; 136 } 137 138 /* If the mqprio options indicate that hardware should own 139 * the queue mapping then run ndo_setup_tc otherwise use the 140 * supplied and verified mapping 141 */ 142 if (qopt->hw) { 143 priv->hw_owned = 1; 144 err = dev->netdev_ops->ndo_setup_tc(dev, qopt->num_tc); 145 if (err) 146 goto err; 147 } else { 148 netdev_set_num_tc(dev, qopt->num_tc); 149 for (i = 0; i < qopt->num_tc; i++) 150 netdev_set_tc_queue(dev, i, 151 qopt->count[i], qopt->offset[i]); 152 } 153 154 /* Always use supplied priority mappings */ 155 for (i = 0; i < TC_BITMASK + 1; i++) 156 netdev_set_prio_tc_map(dev, i, qopt->prio_tc_map[i]); 157 158 sch->flags |= TCQ_F_MQROOT; 159 return 0; 160 161 err: 162 mqprio_destroy(sch); 163 return err; 164 } 165 166 static void mqprio_attach(struct Qdisc *sch) 167 { 168 struct net_device *dev = qdisc_dev(sch); 169 struct mqprio_sched *priv = qdisc_priv(sch); 170 struct Qdisc *qdisc; 171 unsigned int ntx; 172 173 /* Attach underlying qdisc */ 174 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { 175 qdisc = priv->qdiscs[ntx]; 176 qdisc = dev_graft_qdisc(qdisc->dev_queue, qdisc); 177 if (qdisc) 178 qdisc_destroy(qdisc); 179 } 180 kfree(priv->qdiscs); 181 priv->qdiscs = NULL; 182 } 183 184 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch, 185 unsigned long cl) 186 { 187 struct net_device *dev = qdisc_dev(sch); 188 unsigned long ntx = cl - 1 - netdev_get_num_tc(dev); 189 190 if (ntx >= dev->num_tx_queues) 191 return NULL; 192 return netdev_get_tx_queue(dev, ntx); 193 } 194 195 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 196 struct Qdisc **old) 197 { 198 struct net_device *dev = qdisc_dev(sch); 199 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 200 201 if (!dev_queue) 202 return -EINVAL; 203 204 if (dev->flags & IFF_UP) 205 dev_deactivate(dev); 206 207 *old = dev_graft_qdisc(dev_queue, new); 208 209 if (new) 210 new->flags |= TCQ_F_ONETXQUEUE; 211 212 if (dev->flags & IFF_UP) 213 dev_activate(dev); 214 215 return 0; 216 } 217 218 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) 219 { 220 struct net_device *dev = qdisc_dev(sch); 221 struct mqprio_sched *priv = qdisc_priv(sch); 222 unsigned char *b = skb_tail_pointer(skb); 223 struct tc_mqprio_qopt opt = { 0 }; 224 struct Qdisc *qdisc; 225 unsigned int i; 226 227 sch->q.qlen = 0; 228 memset(&sch->bstats, 0, sizeof(sch->bstats)); 229 memset(&sch->qstats, 0, sizeof(sch->qstats)); 230 231 for (i = 0; i < dev->num_tx_queues; i++) { 232 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 233 spin_lock_bh(qdisc_lock(qdisc)); 234 sch->q.qlen += qdisc->q.qlen; 235 sch->bstats.bytes += qdisc->bstats.bytes; 236 sch->bstats.packets += qdisc->bstats.packets; 237 sch->qstats.qlen += qdisc->qstats.qlen; 238 sch->qstats.backlog += qdisc->qstats.backlog; 239 sch->qstats.drops += qdisc->qstats.drops; 240 sch->qstats.requeues += qdisc->qstats.requeues; 241 sch->qstats.overlimits += qdisc->qstats.overlimits; 242 spin_unlock_bh(qdisc_lock(qdisc)); 243 } 244 245 opt.num_tc = netdev_get_num_tc(dev); 246 memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map)); 247 opt.hw = priv->hw_owned; 248 249 for (i = 0; i < netdev_get_num_tc(dev); i++) { 250 opt.count[i] = dev->tc_to_txq[i].count; 251 opt.offset[i] = dev->tc_to_txq[i].offset; 252 } 253 254 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 255 goto nla_put_failure; 256 257 return skb->len; 258 nla_put_failure: 259 nlmsg_trim(skb, b); 260 return -1; 261 } 262 263 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl) 264 { 265 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 266 267 if (!dev_queue) 268 return NULL; 269 270 return dev_queue->qdisc_sleeping; 271 } 272 273 static unsigned long mqprio_get(struct Qdisc *sch, u32 classid) 274 { 275 struct net_device *dev = qdisc_dev(sch); 276 unsigned int ntx = TC_H_MIN(classid); 277 278 if (ntx > dev->num_tx_queues + netdev_get_num_tc(dev)) 279 return 0; 280 return ntx; 281 } 282 283 static void mqprio_put(struct Qdisc *sch, unsigned long cl) 284 { 285 } 286 287 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl, 288 struct sk_buff *skb, struct tcmsg *tcm) 289 { 290 struct net_device *dev = qdisc_dev(sch); 291 292 if (cl <= netdev_get_num_tc(dev)) { 293 tcm->tcm_parent = TC_H_ROOT; 294 tcm->tcm_info = 0; 295 } else { 296 int i; 297 struct netdev_queue *dev_queue; 298 299 dev_queue = mqprio_queue_get(sch, cl); 300 tcm->tcm_parent = 0; 301 for (i = 0; i < netdev_get_num_tc(dev); i++) { 302 struct netdev_tc_txq tc = dev->tc_to_txq[i]; 303 int q_idx = cl - netdev_get_num_tc(dev); 304 305 if (q_idx > tc.offset && 306 q_idx <= tc.offset + tc.count) { 307 tcm->tcm_parent = 308 TC_H_MAKE(TC_H_MAJ(sch->handle), 309 TC_H_MIN(i + 1)); 310 break; 311 } 312 } 313 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 314 } 315 tcm->tcm_handle |= TC_H_MIN(cl); 316 return 0; 317 } 318 319 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 320 struct gnet_dump *d) 321 __releases(d->lock) 322 __acquires(d->lock) 323 { 324 struct net_device *dev = qdisc_dev(sch); 325 326 if (cl <= netdev_get_num_tc(dev)) { 327 int i; 328 struct Qdisc *qdisc; 329 struct gnet_stats_queue qstats = {0}; 330 struct gnet_stats_basic_packed bstats = {0}; 331 struct netdev_tc_txq tc = dev->tc_to_txq[cl - 1]; 332 333 /* Drop lock here it will be reclaimed before touching 334 * statistics this is required because the d->lock we 335 * hold here is the look on dev_queue->qdisc_sleeping 336 * also acquired below. 337 */ 338 spin_unlock_bh(d->lock); 339 340 for (i = tc.offset; i < tc.offset + tc.count; i++) { 341 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 342 spin_lock_bh(qdisc_lock(qdisc)); 343 bstats.bytes += qdisc->bstats.bytes; 344 bstats.packets += qdisc->bstats.packets; 345 qstats.qlen += qdisc->qstats.qlen; 346 qstats.backlog += qdisc->qstats.backlog; 347 qstats.drops += qdisc->qstats.drops; 348 qstats.requeues += qdisc->qstats.requeues; 349 qstats.overlimits += qdisc->qstats.overlimits; 350 spin_unlock_bh(qdisc_lock(qdisc)); 351 } 352 /* Reclaim root sleeping lock before completing stats */ 353 spin_lock_bh(d->lock); 354 if (gnet_stats_copy_basic(d, &bstats) < 0 || 355 gnet_stats_copy_queue(d, &qstats) < 0) 356 return -1; 357 } else { 358 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 359 360 sch = dev_queue->qdisc_sleeping; 361 sch->qstats.qlen = sch->q.qlen; 362 if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || 363 gnet_stats_copy_queue(d, &sch->qstats) < 0) 364 return -1; 365 } 366 return 0; 367 } 368 369 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 370 { 371 struct net_device *dev = qdisc_dev(sch); 372 unsigned long ntx; 373 374 if (arg->stop) 375 return; 376 377 /* Walk hierarchy with a virtual class per tc */ 378 arg->count = arg->skip; 379 for (ntx = arg->skip; 380 ntx < dev->num_tx_queues + netdev_get_num_tc(dev); 381 ntx++) { 382 if (arg->fn(sch, ntx + 1, arg) < 0) { 383 arg->stop = 1; 384 break; 385 } 386 arg->count++; 387 } 388 } 389 390 static const struct Qdisc_class_ops mqprio_class_ops = { 391 .graft = mqprio_graft, 392 .leaf = mqprio_leaf, 393 .get = mqprio_get, 394 .put = mqprio_put, 395 .walk = mqprio_walk, 396 .dump = mqprio_dump_class, 397 .dump_stats = mqprio_dump_class_stats, 398 }; 399 400 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = { 401 .cl_ops = &mqprio_class_ops, 402 .id = "mqprio", 403 .priv_size = sizeof(struct mqprio_sched), 404 .init = mqprio_init, 405 .destroy = mqprio_destroy, 406 .attach = mqprio_attach, 407 .dump = mqprio_dump, 408 .owner = THIS_MODULE, 409 }; 410 411 static int __init mqprio_module_init(void) 412 { 413 return register_qdisc(&mqprio_qdisc_ops); 414 } 415 416 static void __exit mqprio_module_exit(void) 417 { 418 unregister_qdisc(&mqprio_qdisc_ops); 419 } 420 421 module_init(mqprio_module_init); 422 module_exit(mqprio_module_exit); 423 424 MODULE_LICENSE("GPL"); 425