blob: f645ac55a1a13524e4d926d54a4688ad72bf8eb6 [file] [log] [blame]
Alexander Duyck92651942008-09-12 16:29:34 -07001/*
2 * Copyright (c) 2008, Intel Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
16 *
17 * Author: Alexander Duyck <alexander.h.duyck@intel.com>
18 */
19
20#include <linux/module.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/string.h>
24#include <linux/errno.h>
25#include <linux/skbuff.h>
26#include <net/netlink.h>
27#include <net/pkt_sched.h>
28
29
30struct multiq_sched_data {
31 u16 bands;
32 u16 max_bands;
33 u16 curband;
34 struct tcf_proto *filter_list;
35 struct Qdisc **queues;
36};
37
38
39static struct Qdisc *
40multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
41{
42 struct multiq_sched_data *q = qdisc_priv(sch);
43 u32 band;
44 struct tcf_result res;
45 int err;
46
47 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
48 err = tc_classify(skb, q->filter_list, &res);
49#ifdef CONFIG_NET_CLS_ACT
50 switch (err) {
51 case TC_ACT_STOLEN:
52 case TC_ACT_QUEUED:
53 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
54 case TC_ACT_SHOT:
55 return NULL;
56 }
57#endif
58 band = skb_get_queue_mapping(skb);
59
60 if (band >= q->bands)
61 return q->queues[0];
62
63 return q->queues[band];
64}
65
66static int
67multiq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
68{
69 struct Qdisc *qdisc;
70 int ret;
71
72 qdisc = multiq_classify(skb, sch, &ret);
73#ifdef CONFIG_NET_CLS_ACT
74 if (qdisc == NULL) {
75
76 if (ret & __NET_XMIT_BYPASS)
77 sch->qstats.drops++;
78 kfree_skb(skb);
79 return ret;
80 }
81#endif
82
83 ret = qdisc_enqueue(skb, qdisc);
84 if (ret == NET_XMIT_SUCCESS) {
85 sch->bstats.bytes += qdisc_pkt_len(skb);
86 sch->bstats.packets++;
87 sch->q.qlen++;
88 return NET_XMIT_SUCCESS;
89 }
90 if (net_xmit_drop_count(ret))
91 sch->qstats.drops++;
92 return ret;
93}
94
Alexander Duyck92651942008-09-12 16:29:34 -070095static struct sk_buff *multiq_dequeue(struct Qdisc *sch)
96{
97 struct multiq_sched_data *q = qdisc_priv(sch);
98 struct Qdisc *qdisc;
99 struct sk_buff *skb;
100 int band;
101
102 for (band = 0; band < q->bands; band++) {
103 /* cycle through bands to ensure fairness */
104 q->curband++;
105 if (q->curband >= q->bands)
106 q->curband = 0;
107
108 /* Check that target subqueue is available before
Jarek Poplawskif30ab412008-11-13 22:56:30 -0800109 * pulling an skb to avoid head-of-line blocking.
Alexander Duyck92651942008-09-12 16:29:34 -0700110 */
111 if (!__netif_subqueue_stopped(qdisc_dev(sch), q->curband)) {
112 qdisc = q->queues[q->curband];
113 skb = qdisc->dequeue(qdisc);
114 if (skb) {
115 sch->q.qlen--;
116 return skb;
117 }
118 }
119 }
120 return NULL;
121
122}
123
Jarek Poplawski8e3af972008-10-31 00:45:55 -0700124static struct sk_buff *multiq_peek(struct Qdisc *sch)
125{
126 struct multiq_sched_data *q = qdisc_priv(sch);
127 unsigned int curband = q->curband;
128 struct Qdisc *qdisc;
129 struct sk_buff *skb;
130 int band;
131
132 for (band = 0; band < q->bands; band++) {
133 /* cycle through bands to ensure fairness */
134 curband++;
135 if (curband >= q->bands)
136 curband = 0;
137
138 /* Check that target subqueue is available before
Jarek Poplawskif30ab412008-11-13 22:56:30 -0800139 * pulling an skb to avoid head-of-line blocking.
Jarek Poplawski8e3af972008-10-31 00:45:55 -0700140 */
141 if (!__netif_subqueue_stopped(qdisc_dev(sch), curband)) {
142 qdisc = q->queues[curband];
143 skb = qdisc->ops->peek(qdisc);
144 if (skb)
145 return skb;
146 }
147 }
148 return NULL;
149
150}
151
Alexander Duyck92651942008-09-12 16:29:34 -0700152static unsigned int multiq_drop(struct Qdisc *sch)
153{
154 struct multiq_sched_data *q = qdisc_priv(sch);
155 int band;
156 unsigned int len;
157 struct Qdisc *qdisc;
158
159 for (band = q->bands-1; band >= 0; band--) {
160 qdisc = q->queues[band];
161 if (qdisc->ops->drop) {
162 len = qdisc->ops->drop(qdisc);
163 if (len != 0) {
164 sch->q.qlen--;
165 return len;
166 }
167 }
168 }
169 return 0;
170}
171
172
173static void
174multiq_reset(struct Qdisc *sch)
175{
176 u16 band;
177 struct multiq_sched_data *q = qdisc_priv(sch);
178
179 for (band = 0; band < q->bands; band++)
180 qdisc_reset(q->queues[band]);
181 sch->q.qlen = 0;
182 q->curband = 0;
183}
184
185static void
186multiq_destroy(struct Qdisc *sch)
187{
188 int band;
189 struct multiq_sched_data *q = qdisc_priv(sch);
190
191 tcf_destroy_chain(&q->filter_list);
192 for (band = 0; band < q->bands; band++)
193 qdisc_destroy(q->queues[band]);
194
195 kfree(q->queues);
196}
197
198static int multiq_tune(struct Qdisc *sch, struct nlattr *opt)
199{
200 struct multiq_sched_data *q = qdisc_priv(sch);
201 struct tc_multiq_qopt *qopt;
202 int i;
203
204 if (!netif_is_multiqueue(qdisc_dev(sch)))
205 return -EINVAL;
206 if (nla_len(opt) < sizeof(*qopt))
207 return -EINVAL;
208
209 qopt = nla_data(opt);
210
211 qopt->bands = qdisc_dev(sch)->real_num_tx_queues;
212
213 sch_tree_lock(sch);
214 q->bands = qopt->bands;
215 for (i = q->bands; i < q->max_bands; i++) {
Alexander Duyckf07d1502008-09-12 17:57:23 -0700216 if (q->queues[i] != &noop_qdisc) {
217 struct Qdisc *child = xchg(&q->queues[i], &noop_qdisc);
Alexander Duyck92651942008-09-12 16:29:34 -0700218 qdisc_tree_decrease_qlen(child, child->q.qlen);
219 qdisc_destroy(child);
220 }
221 }
222
223 sch_tree_unlock(sch);
224
225 for (i = 0; i < q->bands; i++) {
226 if (q->queues[i] == &noop_qdisc) {
227 struct Qdisc *child;
228 child = qdisc_create_dflt(qdisc_dev(sch),
229 sch->dev_queue,
230 &pfifo_qdisc_ops,
231 TC_H_MAKE(sch->handle,
232 i + 1));
233 if (child) {
234 sch_tree_lock(sch);
235 child = xchg(&q->queues[i], child);
236
237 if (child != &noop_qdisc) {
238 qdisc_tree_decrease_qlen(child,
239 child->q.qlen);
240 qdisc_destroy(child);
241 }
242 sch_tree_unlock(sch);
243 }
244 }
245 }
246 return 0;
247}
248
249static int multiq_init(struct Qdisc *sch, struct nlattr *opt)
250{
251 struct multiq_sched_data *q = qdisc_priv(sch);
Alexander Duyckf07d1502008-09-12 17:57:23 -0700252 int i, err;
Alexander Duyck92651942008-09-12 16:29:34 -0700253
254 q->queues = NULL;
255
256 if (opt == NULL)
257 return -EINVAL;
258
259 q->max_bands = qdisc_dev(sch)->num_tx_queues;
260
261 q->queues = kcalloc(q->max_bands, sizeof(struct Qdisc *), GFP_KERNEL);
262 if (!q->queues)
263 return -ENOBUFS;
264 for (i = 0; i < q->max_bands; i++)
265 q->queues[i] = &noop_qdisc;
266
Alexander Duyckf07d1502008-09-12 17:57:23 -0700267 err = multiq_tune(sch,opt);
268
269 if (err)
270 kfree(q->queues);
271
272 return err;
Alexander Duyck92651942008-09-12 16:29:34 -0700273}
274
275static int multiq_dump(struct Qdisc *sch, struct sk_buff *skb)
276{
277 struct multiq_sched_data *q = qdisc_priv(sch);
278 unsigned char *b = skb_tail_pointer(skb);
279 struct tc_multiq_qopt opt;
280
281 opt.bands = q->bands;
282 opt.max_bands = q->max_bands;
283
284 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
285
286 return skb->len;
287
288nla_put_failure:
289 nlmsg_trim(skb, b);
290 return -1;
291}
292
293static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
294 struct Qdisc **old)
295{
296 struct multiq_sched_data *q = qdisc_priv(sch);
297 unsigned long band = arg - 1;
298
299 if (band >= q->bands)
300 return -EINVAL;
301
302 if (new == NULL)
303 new = &noop_qdisc;
304
305 sch_tree_lock(sch);
306 *old = q->queues[band];
307 q->queues[band] = new;
308 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
309 qdisc_reset(*old);
310 sch_tree_unlock(sch);
311
312 return 0;
313}
314
315static struct Qdisc *
316multiq_leaf(struct Qdisc *sch, unsigned long arg)
317{
318 struct multiq_sched_data *q = qdisc_priv(sch);
319 unsigned long band = arg - 1;
320
321 if (band >= q->bands)
322 return NULL;
323
324 return q->queues[band];
325}
326
327static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
328{
329 struct multiq_sched_data *q = qdisc_priv(sch);
330 unsigned long band = TC_H_MIN(classid);
331
332 if (band - 1 >= q->bands)
333 return 0;
334 return band;
335}
336
337static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
338 u32 classid)
339{
340 return multiq_get(sch, classid);
341}
342
343
344static void multiq_put(struct Qdisc *q, unsigned long cl)
345{
346 return;
347}
348
349static int multiq_change(struct Qdisc *sch, u32 handle, u32 parent,
350 struct nlattr **tca, unsigned long *arg)
351{
352 unsigned long cl = *arg;
353 struct multiq_sched_data *q = qdisc_priv(sch);
354
355 if (cl - 1 > q->bands)
356 return -ENOENT;
357 return 0;
358}
359
360static int multiq_delete(struct Qdisc *sch, unsigned long cl)
361{
362 struct multiq_sched_data *q = qdisc_priv(sch);
363 if (cl - 1 > q->bands)
364 return -ENOENT;
365 return 0;
366}
367
368
369static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
370 struct sk_buff *skb, struct tcmsg *tcm)
371{
372 struct multiq_sched_data *q = qdisc_priv(sch);
373
374 if (cl - 1 > q->bands)
375 return -ENOENT;
376 tcm->tcm_handle |= TC_H_MIN(cl);
377 if (q->queues[cl-1])
378 tcm->tcm_info = q->queues[cl-1]->handle;
379 return 0;
380}
381
382static int multiq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
383 struct gnet_dump *d)
384{
385 struct multiq_sched_data *q = qdisc_priv(sch);
386 struct Qdisc *cl_q;
387
388 cl_q = q->queues[cl - 1];
389 if (gnet_stats_copy_basic(d, &cl_q->bstats) < 0 ||
390 gnet_stats_copy_queue(d, &cl_q->qstats) < 0)
391 return -1;
392
393 return 0;
394}
395
396static void multiq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
397{
398 struct multiq_sched_data *q = qdisc_priv(sch);
399 int band;
400
401 if (arg->stop)
402 return;
403
404 for (band = 0; band < q->bands; band++) {
405 if (arg->count < arg->skip) {
406 arg->count++;
407 continue;
408 }
409 if (arg->fn(sch, band+1, arg) < 0) {
410 arg->stop = 1;
411 break;
412 }
413 arg->count++;
414 }
415}
416
417static struct tcf_proto **multiq_find_tcf(struct Qdisc *sch, unsigned long cl)
418{
419 struct multiq_sched_data *q = qdisc_priv(sch);
420
421 if (cl)
422 return NULL;
423 return &q->filter_list;
424}
425
426static const struct Qdisc_class_ops multiq_class_ops = {
427 .graft = multiq_graft,
428 .leaf = multiq_leaf,
429 .get = multiq_get,
430 .put = multiq_put,
431 .change = multiq_change,
432 .delete = multiq_delete,
433 .walk = multiq_walk,
434 .tcf_chain = multiq_find_tcf,
435 .bind_tcf = multiq_bind,
436 .unbind_tcf = multiq_put,
437 .dump = multiq_dump_class,
438 .dump_stats = multiq_dump_class_stats,
439};
440
441static struct Qdisc_ops multiq_qdisc_ops __read_mostly = {
442 .next = NULL,
443 .cl_ops = &multiq_class_ops,
444 .id = "multiq",
445 .priv_size = sizeof(struct multiq_sched_data),
446 .enqueue = multiq_enqueue,
447 .dequeue = multiq_dequeue,
Jarek Poplawski8e3af972008-10-31 00:45:55 -0700448 .peek = multiq_peek,
Alexander Duyck92651942008-09-12 16:29:34 -0700449 .drop = multiq_drop,
450 .init = multiq_init,
451 .reset = multiq_reset,
452 .destroy = multiq_destroy,
453 .change = multiq_tune,
454 .dump = multiq_dump,
455 .owner = THIS_MODULE,
456};
457
458static int __init multiq_module_init(void)
459{
460 return register_qdisc(&multiq_qdisc_ops);
461}
462
463static void __exit multiq_module_exit(void)
464{
465 unregister_qdisc(&multiq_qdisc_ops);
466}
467
468module_init(multiq_module_init)
469module_exit(multiq_module_exit)
470
471MODULE_LICENSE("GPL");