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, tp: fl, res: &res, compat_mode: 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, qerr: &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, sch: 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 | dev_queue: netdev_get_tx_queue(dev: qdisc_dev(qdisc: sch), index: 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 | dev_queue: netdev_get_tx_queue(dev: qdisc_dev(qdisc: sch), index: 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(qdisc: 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(block: q->block); |
165 | for (band = 0; band < q->bands; band++) |
166 | qdisc_put(qdisc: q->queues[band]); |
167 | |
168 | kfree(objp: 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(dev: qdisc_dev(qdisc: sch))) |
180 | return -EOPNOTSUPP; |
181 | if (nla_len(nla: opt) < sizeof(*qopt)) |
182 | return -EINVAL; |
183 | |
184 | qopt = nla_data(nla: opt); |
185 | |
186 | qopt->bands = qdisc_dev(qdisc: sch)->real_num_tx_queues; |
187 | |
188 | removed = kmalloc(size: sizeof(*removed) * (q->max_bands - q->bands), |
189 | GFP_KERNEL); |
190 | if (!removed) |
191 | return -ENOMEM; |
192 | |
193 | sch_tree_lock(q: 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(sch: child); |
201 | removed[n_removed++] = child; |
202 | } |
203 | } |
204 | |
205 | sch_tree_unlock(q: sch); |
206 | |
207 | for (i = 0; i < n_removed; i++) |
208 | qdisc_put(qdisc: removed[i]); |
209 | kfree(objp: 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(dev_queue: sch->dev_queue, |
215 | ops: &pfifo_qdisc_ops, |
216 | TC_H_MAKE(sch->handle, |
217 | i + 1), extack); |
218 | if (child) { |
219 | sch_tree_lock(q: sch); |
220 | old = q->queues[i]; |
221 | q->queues[i] = child; |
222 | if (child != &noop_qdisc) |
223 | qdisc_hash_add(q: child, invisible: true); |
224 | |
225 | if (old != &noop_qdisc) |
226 | qdisc_purge_queue(sch: old); |
227 | sch_tree_unlock(q: sch); |
228 | qdisc_put(qdisc: 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(p_block: &q->block, p_filter_chain: &q->filter_list, q: sch, extack); |
247 | if (err) |
248 | return err; |
249 | |
250 | q->max_bands = qdisc_dev(qdisc: sch)->num_tx_queues; |
251 | |
252 | q->queues = kcalloc(n: q->max_bands, size: 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, attrtype: TCA_OPTIONS, attrlen: sizeof(opt), data: &opt)) |
271 | goto nla_put_failure; |
272 | |
273 | return skb->len; |
274 | |
275 | nla_put_failure: |
276 | nlmsg_trim(skb, mark: 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, pold: &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, cpu: cl_q->cpu_bstats, b: &cl_q->bstats, running: true) < 0 || |
341 | qdisc_qstats_copy(d, sch: 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, cl: 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(qops: &multiq_qdisc_ops); |
402 | } |
403 | |
404 | static void __exit multiq_module_exit(void) |
405 | { |
406 | unregister_qdisc(qops: &multiq_qdisc_ops); |
407 | } |
408 | |
409 | module_init(multiq_module_init) |
410 | module_exit(multiq_module_exit) |
411 | |
412 | MODULE_LICENSE("GPL" ); |
413 | |