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, default_qdisc_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, *old; 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 old = dev_graft_qdisc(qdisc->dev_queue, qdisc); 177 if (old) 178 qdisc_destroy(old); 179 if (ntx < dev->real_num_tx_queues) 180 qdisc_list_add(qdisc); 181 } 182 kfree(priv->qdiscs); 183 priv->qdiscs = NULL; 184 } 185 186 static struct netdev_queue *mqprio_queue_get(struct Qdisc *sch, 187 unsigned long cl) 188 { 189 struct net_device *dev = qdisc_dev(sch); 190 unsigned long ntx = cl - 1 - netdev_get_num_tc(dev); 191 192 if (ntx >= dev->num_tx_queues) 193 return NULL; 194 return netdev_get_tx_queue(dev, ntx); 195 } 196 197 static int mqprio_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new, 198 struct Qdisc **old) 199 { 200 struct net_device *dev = qdisc_dev(sch); 201 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 202 203 if (!dev_queue) 204 return -EINVAL; 205 206 if (dev->flags & IFF_UP) 207 dev_deactivate(dev); 208 209 *old = dev_graft_qdisc(dev_queue, new); 210 211 if (new) 212 new->flags |= TCQ_F_ONETXQUEUE; 213 214 if (dev->flags & IFF_UP) 215 dev_activate(dev); 216 217 return 0; 218 } 219 220 static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) 221 { 222 struct net_device *dev = qdisc_dev(sch); 223 struct mqprio_sched *priv = qdisc_priv(sch); 224 unsigned char *b = skb_tail_pointer(skb); 225 struct tc_mqprio_qopt opt = { 0 }; 226 struct Qdisc *qdisc; 227 unsigned int i; 228 229 sch->q.qlen = 0; 230 memset(&sch->bstats, 0, sizeof(sch->bstats)); 231 memset(&sch->qstats, 0, sizeof(sch->qstats)); 232 233 for (i = 0; i < dev->num_tx_queues; i++) { 234 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 235 spin_lock_bh(qdisc_lock(qdisc)); 236 sch->q.qlen += qdisc->q.qlen; 237 sch->bstats.bytes += qdisc->bstats.bytes; 238 sch->bstats.packets += qdisc->bstats.packets; 239 sch->qstats.qlen += qdisc->qstats.qlen; 240 sch->qstats.backlog += qdisc->qstats.backlog; 241 sch->qstats.drops += qdisc->qstats.drops; 242 sch->qstats.requeues += qdisc->qstats.requeues; 243 sch->qstats.overlimits += qdisc->qstats.overlimits; 244 spin_unlock_bh(qdisc_lock(qdisc)); 245 } 246 247 opt.num_tc = netdev_get_num_tc(dev); 248 memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map)); 249 opt.hw = priv->hw_owned; 250 251 for (i = 0; i < netdev_get_num_tc(dev); i++) { 252 opt.count[i] = dev->tc_to_txq[i].count; 253 opt.offset[i] = dev->tc_to_txq[i].offset; 254 } 255 256 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) 257 goto nla_put_failure; 258 259 return skb->len; 260 nla_put_failure: 261 nlmsg_trim(skb, b); 262 return -1; 263 } 264 265 static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl) 266 { 267 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 268 269 if (!dev_queue) 270 return NULL; 271 272 return dev_queue->qdisc_sleeping; 273 } 274 275 static unsigned long mqprio_get(struct Qdisc *sch, u32 classid) 276 { 277 struct net_device *dev = qdisc_dev(sch); 278 unsigned int ntx = TC_H_MIN(classid); 279 280 if (ntx > dev->num_tx_queues + netdev_get_num_tc(dev)) 281 return 0; 282 return ntx; 283 } 284 285 static void mqprio_put(struct Qdisc *sch, unsigned long cl) 286 { 287 } 288 289 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl, 290 struct sk_buff *skb, struct tcmsg *tcm) 291 { 292 struct net_device *dev = qdisc_dev(sch); 293 294 if (cl <= netdev_get_num_tc(dev)) { 295 tcm->tcm_parent = TC_H_ROOT; 296 tcm->tcm_info = 0; 297 } else { 298 int i; 299 struct netdev_queue *dev_queue; 300 301 dev_queue = mqprio_queue_get(sch, cl); 302 tcm->tcm_parent = 0; 303 for (i = 0; i < netdev_get_num_tc(dev); i++) { 304 struct netdev_tc_txq tc = dev->tc_to_txq[i]; 305 int q_idx = cl - netdev_get_num_tc(dev); 306 307 if (q_idx > tc.offset && 308 q_idx <= tc.offset + tc.count) { 309 tcm->tcm_parent = 310 TC_H_MAKE(TC_H_MAJ(sch->handle), 311 TC_H_MIN(i + 1)); 312 break; 313 } 314 } 315 tcm->tcm_info = dev_queue->qdisc_sleeping->handle; 316 } 317 tcm->tcm_handle |= TC_H_MIN(cl); 318 return 0; 319 } 320 321 static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, 322 struct gnet_dump *d) 323 __releases(d->lock) 324 __acquires(d->lock) 325 { 326 struct net_device *dev = qdisc_dev(sch); 327 328 if (cl <= netdev_get_num_tc(dev)) { 329 int i; 330 struct Qdisc *qdisc; 331 struct gnet_stats_queue qstats = {0}; 332 struct gnet_stats_basic_packed bstats = {0}; 333 struct netdev_tc_txq tc = dev->tc_to_txq[cl - 1]; 334 335 /* Drop lock here it will be reclaimed before touching 336 * statistics this is required because the d->lock we 337 * hold here is the look on dev_queue->qdisc_sleeping 338 * also acquired below. 339 */ 340 spin_unlock_bh(d->lock); 341 342 for (i = tc.offset; i < tc.offset + tc.count; i++) { 343 qdisc = netdev_get_tx_queue(dev, i)->qdisc; 344 spin_lock_bh(qdisc_lock(qdisc)); 345 bstats.bytes += qdisc->bstats.bytes; 346 bstats.packets += qdisc->bstats.packets; 347 qstats.qlen += qdisc->qstats.qlen; 348 qstats.backlog += qdisc->qstats.backlog; 349 qstats.drops += qdisc->qstats.drops; 350 qstats.requeues += qdisc->qstats.requeues; 351 qstats.overlimits += qdisc->qstats.overlimits; 352 spin_unlock_bh(qdisc_lock(qdisc)); 353 } 354 /* Reclaim root sleeping lock before completing stats */ 355 spin_lock_bh(d->lock); 356 if (gnet_stats_copy_basic(d, &bstats) < 0 || 357 gnet_stats_copy_queue(d, &qstats) < 0) 358 return -1; 359 } else { 360 struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl); 361 362 sch = dev_queue->qdisc_sleeping; 363 sch->qstats.qlen = sch->q.qlen; 364 if (gnet_stats_copy_basic(d, &sch->bstats) < 0 || 365 gnet_stats_copy_queue(d, &sch->qstats) < 0) 366 return -1; 367 } 368 return 0; 369 } 370 371 static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg) 372 { 373 struct net_device *dev = qdisc_dev(sch); 374 unsigned long ntx; 375 376 if (arg->stop) 377 return; 378 379 /* Walk hierarchy with a virtual class per tc */ 380 arg->count = arg->skip; 381 for (ntx = arg->skip; 382 ntx < dev->num_tx_queues + netdev_get_num_tc(dev); 383 ntx++) { 384 if (arg->fn(sch, ntx + 1, arg) < 0) { 385 arg->stop = 1; 386 break; 387 } 388 arg->count++; 389 } 390 } 391 392 static const struct Qdisc_class_ops mqprio_class_ops = { 393 .graft = mqprio_graft, 394 .leaf = mqprio_leaf, 395 .get = mqprio_get, 396 .put = mqprio_put, 397 .walk = mqprio_walk, 398 .dump = mqprio_dump_class, 399 .dump_stats = mqprio_dump_class_stats, 400 }; 401 402 static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = { 403 .cl_ops = &mqprio_class_ops, 404 .id = "mqprio", 405 .priv_size = sizeof(struct mqprio_sched), 406 .init = mqprio_init, 407 .destroy = mqprio_destroy, 408 .attach = mqprio_attach, 409 .dump = mqprio_dump, 410 .owner = THIS_MODULE, 411 }; 412 413 static int __init mqprio_module_init(void) 414 { 415 return register_qdisc(&mqprio_qdisc_ops); 416 } 417 418 static void __exit mqprio_module_exit(void) 419 { 420 unregister_qdisc(&mqprio_qdisc_ops); 421 } 422 423 module_init(mqprio_module_init); 424 module_exit(mqprio_module_exit); 425 426 MODULE_LICENSE("GPL"); 427