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drm/i915: Use mmio flips to change tiling mode on Baytrail
[linux-2.6/btrfs-unstable.git] / net / sched / cls_tcindex.c
blobc721cd4a469fe39f42186d82ec7ab04f17bcba26
1 /*
2 * net/sched/cls_tcindex.c Packet classifier for skb->tc_index
3 *
4 * Written 1998,1999 by Werner Almesberger, EPFL ICA
5 */
6
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/skbuff.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <net/act_api.h>
14 #include <net/netlink.h>
15 #include <net/pkt_cls.h>
16
17 /*
18 * Passing parameters to the root seems to be done more awkwardly than really
19 * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
20 * verified. FIXME.
21 */
22
23 #define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
24 #define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
25
26
27 struct tcindex_filter_result {
28 struct tcf_exts exts;
29 struct tcf_result res;
30 };
31
32 struct tcindex_filter {
33 u16 key;
34 struct tcindex_filter_result result;
35 struct tcindex_filter *next;
36 };
37
38
39 struct tcindex_data {
40 struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
41 struct tcindex_filter **h; /* imperfect hash; only used if !perfect;
42 NULL if unused */
43 u16 mask; /* AND key with mask */
44 int shift; /* shift ANDed key to the right */
45 int hash; /* hash table size; 0 if undefined */
46 int alloc_hash; /* allocated size */
47 int fall_through; /* 0: only classify if explicit match */
48 };
49
50 static inline int
51 tcindex_filter_is_set(struct tcindex_filter_result *r)
52 {
53 return tcf_exts_is_predicative(&r->exts) || r->res.classid;
54 }
55
56 static struct tcindex_filter_result *
57 tcindex_lookup(struct tcindex_data *p, u16 key)
58 {
59 struct tcindex_filter *f;
60
61 if (p->perfect)
62 return tcindex_filter_is_set(p->perfect + key) ?
63 p->perfect + key : NULL;
64 else if (p->h) {
65 for (f = p->h[key % p->hash]; f; f = f->next)
66 if (f->key == key)
67 return &f->result;
68 }
69
70 return NULL;
71 }
72
73
74 static int tcindex_classify(struct sk_buff *skb, const struct tcf_proto *tp,
75 struct tcf_result *res)
76 {
77 struct tcindex_data *p = tp->root;
78 struct tcindex_filter_result *f;
79 int key = (skb->tc_index & p->mask) >> p->shift;
80
81 pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
82 skb, tp, res, p);
83
84 f = tcindex_lookup(p, key);
85 if (!f) {
86 if (!p->fall_through)
87 return -1;
88 res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key);
89 res->class = 0;
90 pr_debug("alg 0x%x\n", res->classid);
91 return 0;
92 }
93 *res = f->res;
94 pr_debug("map 0x%x\n", res->classid);
95
96 return tcf_exts_exec(skb, &f->exts, res);
97 }
98
99
100 static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
101 {
102 struct tcindex_data *p = tp->root;
103 struct tcindex_filter_result *r;
104
105 pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
106 if (p->perfect && handle >= p->alloc_hash)
107 return 0;
108 r = tcindex_lookup(p, handle);
109 return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
110 }
111
112
113 static void tcindex_put(struct tcf_proto *tp, unsigned long f)
114 {
115 pr_debug("tcindex_put(tp %p,f 0x%lx)\n", tp, f);
116 }
117
118
119 static int tcindex_init(struct tcf_proto *tp)
120 {
121 struct tcindex_data *p;
122
123 pr_debug("tcindex_init(tp %p)\n", tp);
124 p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
125 if (!p)
126 return -ENOMEM;
127
128 p->mask = 0xffff;
129 p->hash = DEFAULT_HASH_SIZE;
130 p->fall_through = 1;
131
132 tp->root = p;
133 return 0;
134 }
135
136
137 static int
138 __tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
139 {
140 struct tcindex_data *p = tp->root;
141 struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
142 struct tcindex_filter *f = NULL;
143
144 pr_debug("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n", tp, arg, p, f);
145 if (p->perfect) {
146 if (!r->res.class)
147 return -ENOENT;
148 } else {
149 int i;
150 struct tcindex_filter **walk = NULL;
151
152 for (i = 0; i < p->hash; i++)
153 for (walk = p->h+i; *walk; walk = &(*walk)->next)
154 if (&(*walk)->result == r)
155 goto found;
156 return -ENOENT;
157
158 found:
159 f = *walk;
160 if (lock)
161 tcf_tree_lock(tp);
162 *walk = f->next;
163 if (lock)
164 tcf_tree_unlock(tp);
165 }
166 tcf_unbind_filter(tp, &r->res);
167 tcf_exts_destroy(tp, &r->exts);
168 kfree(f);
169 return 0;
170 }
171
172 static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
173 {
174 return __tcindex_delete(tp, arg, 1);
175 }
176
177 static inline int
178 valid_perfect_hash(struct tcindex_data *p)
179 {
180 return p->hash > (p->mask >> p->shift);
181 }
182
183 static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
184 [TCA_TCINDEX_HASH] = { .type = NLA_U32 },
185 [TCA_TCINDEX_MASK] = { .type = NLA_U16 },
186 [TCA_TCINDEX_SHIFT] = { .type = NLA_U32 },
187 [TCA_TCINDEX_FALL_THROUGH] = { .type = NLA_U32 },
188 [TCA_TCINDEX_CLASSID] = { .type = NLA_U32 },
189 };
190
191 static void tcindex_filter_result_init(struct tcindex_filter_result *r)
192 {
193 memset(r, 0, sizeof(*r));
194 tcf_exts_init(&r->exts, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
195 }
196
197 static int
198 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
199 u32 handle, struct tcindex_data *p,
200 struct tcindex_filter_result *r, struct nlattr **tb,
201 struct nlattr *est, bool ovr)
202 {
203 int err, balloc = 0;
204 struct tcindex_filter_result new_filter_result, *old_r = r;
205 struct tcindex_filter_result cr;
206 struct tcindex_data cp;
207 struct tcindex_filter *f = NULL; /* make gcc behave */
208 struct tcf_exts e;
209
210 tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
211 err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
212 if (err < 0)
213 return err;
214
215 memcpy(&cp, p, sizeof(cp));
216 tcindex_filter_result_init(&new_filter_result);
217
218 tcindex_filter_result_init(&cr);
219 if (old_r)
220 cr.res = r->res;
221
222 if (tb[TCA_TCINDEX_HASH])
223 cp.hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
224
225 if (tb[TCA_TCINDEX_MASK])
226 cp.mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
227
228 if (tb[TCA_TCINDEX_SHIFT])
229 cp.shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
230
231 err = -EBUSY;
232 /* Hash already allocated, make sure that we still meet the
233 * requirements for the allocated hash.
234 */
235 if (cp.perfect) {
236 if (!valid_perfect_hash(&cp) ||
237 cp.hash > cp.alloc_hash)
238 goto errout;
239 } else if (cp.h && cp.hash != cp.alloc_hash)
240 goto errout;
241
242 err = -EINVAL;
243 if (tb[TCA_TCINDEX_FALL_THROUGH])
244 cp.fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
245
246 if (!cp.hash) {
247 /* Hash not specified, use perfect hash if the upper limit
248 * of the hashing index is below the threshold.
249 */
250 if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD)
251 cp.hash = (cp.mask >> cp.shift) + 1;
252 else
253 cp.hash = DEFAULT_HASH_SIZE;
254 }
255
256 if (!cp.perfect && !cp.h)
257 cp.alloc_hash = cp.hash;
258
259 /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
260 * but then, we'd fail handles that may become valid after some future
261 * mask change. While this is extremely unlikely to ever matter,
262 * the check below is safer (and also more backwards-compatible).
263 */
264 if (cp.perfect || valid_perfect_hash(&cp))
265 if (handle >= cp.alloc_hash)
266 goto errout;
267
268
269 err = -ENOMEM;
270 if (!cp.perfect && !cp.h) {
271 if (valid_perfect_hash(&cp)) {
272 int i;
273
274 cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
275 if (!cp.perfect)
276 goto errout;
277 for (i = 0; i < cp.hash; i++)
278 tcf_exts_init(&cp.perfect[i].exts, TCA_TCINDEX_ACT,
279 TCA_TCINDEX_POLICE);
280 balloc = 1;
281 } else {
282 cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
283 if (!cp.h)
284 goto errout;
285 balloc = 2;
286 }
287 }
288
289 if (cp.perfect)
290 r = cp.perfect + handle;
291 else
292 r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
293
294 if (r == &new_filter_result) {
295 f = kzalloc(sizeof(*f), GFP_KERNEL);
296 if (!f)
297 goto errout_alloc;
298 }
299
300 if (tb[TCA_TCINDEX_CLASSID]) {
301 cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
302 tcf_bind_filter(tp, &cr.res, base);
303 }
304
305 if (old_r)
306 tcf_exts_change(tp, &r->exts, &e);
307 else
308 tcf_exts_change(tp, &cr.exts, &e);
309
310 tcf_tree_lock(tp);
311 if (old_r && old_r != r)
312 tcindex_filter_result_init(old_r);
313
314 memcpy(p, &cp, sizeof(cp));
315 r->res = cr.res;
316
317 if (r == &new_filter_result) {
318 struct tcindex_filter **fp;
319
320 f->key = handle;
321 f->result = new_filter_result;
322 f->next = NULL;
323 for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
324 /* nothing */;
325 *fp = f;
326 }
327 tcf_tree_unlock(tp);
328
329 return 0;
330
331 errout_alloc:
332 if (balloc == 1)
333 kfree(cp.perfect);
334 else if (balloc == 2)
335 kfree(cp.h);
336 errout:
337 tcf_exts_destroy(tp, &e);
338 return err;
339 }
340
341 static int
342 tcindex_change(struct net *net, struct sk_buff *in_skb,
343 struct tcf_proto *tp, unsigned long base, u32 handle,
344 struct nlattr **tca, unsigned long *arg, bool ovr)
345 {
346 struct nlattr *opt = tca[TCA_OPTIONS];
347 struct nlattr *tb[TCA_TCINDEX_MAX + 1];
348 struct tcindex_data *p = tp->root;
349 struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
350 int err;
351
352 pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
353 "p %p,r %p,*arg 0x%lx\n",
354 tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
355
356 if (!opt)
357 return 0;
358
359 err = nla_parse_nested(tb, TCA_TCINDEX_MAX, opt, tcindex_policy);
360 if (err < 0)
361 return err;
362
363 return tcindex_set_parms(net, tp, base, handle, p, r, tb,
364 tca[TCA_RATE], ovr);
365 }
366
367
368 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
369 {
370 struct tcindex_data *p = tp->root;
371 struct tcindex_filter *f, *next;
372 int i;
373
374 pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
375 if (p->perfect) {
376 for (i = 0; i < p->hash; i++) {
377 if (!p->perfect[i].res.class)
378 continue;
379 if (walker->count >= walker->skip) {
380 if (walker->fn(tp,
381 (unsigned long) (p->perfect+i), walker)
382 < 0) {
383 walker->stop = 1;
384 return;
385 }
386 }
387 walker->count++;
388 }
389 }
390 if (!p->h)
391 return;
392 for (i = 0; i < p->hash; i++) {
393 for (f = p->h[i]; f; f = next) {
394 next = f->next;
395 if (walker->count >= walker->skip) {
396 if (walker->fn(tp, (unsigned long) &f->result,
397 walker) < 0) {
398 walker->stop = 1;
399 return;
400 }
401 }
402 walker->count++;
403 }
404 }
405 }
406
407
408 static int tcindex_destroy_element(struct tcf_proto *tp,
409 unsigned long arg, struct tcf_walker *walker)
410 {
411 return __tcindex_delete(tp, arg, 0);
412 }
413
414
415 static void tcindex_destroy(struct tcf_proto *tp)
416 {
417 struct tcindex_data *p = tp->root;
418 struct tcf_walker walker;
419
420 pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
421 walker.count = 0;
422 walker.skip = 0;
423 walker.fn = &tcindex_destroy_element;
424 tcindex_walk(tp, &walker);
425 kfree(p->perfect);
426 kfree(p->h);
427 kfree(p);
428 tp->root = NULL;
429 }
430
431
432 static int tcindex_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
433 struct sk_buff *skb, struct tcmsg *t)
434 {
435 struct tcindex_data *p = tp->root;
436 struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
437 unsigned char *b = skb_tail_pointer(skb);
438 struct nlattr *nest;
439
440 pr_debug("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
441 tp, fh, skb, t, p, r, b);
442 pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
443
444 nest = nla_nest_start(skb, TCA_OPTIONS);
445 if (nest == NULL)
446 goto nla_put_failure;
447
448 if (!fh) {
449 t->tcm_handle = ~0; /* whatever ... */
450 if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
451 nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
452 nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
453 nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
454 goto nla_put_failure;
455 nla_nest_end(skb, nest);
456 } else {
457 if (p->perfect) {
458 t->tcm_handle = r-p->perfect;
459 } else {
460 struct tcindex_filter *f;
461 int i;
462
463 t->tcm_handle = 0;
464 for (i = 0; !t->tcm_handle && i < p->hash; i++) {
465 for (f = p->h[i]; !t->tcm_handle && f;
466 f = f->next) {
467 if (&f->result == r)
468 t->tcm_handle = f->key;
469 }
470 }
471 }
472 pr_debug("handle = %d\n", t->tcm_handle);
473 if (r->res.class &&
474 nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
475 goto nla_put_failure;
476
477 if (tcf_exts_dump(skb, &r->exts) < 0)
478 goto nla_put_failure;
479 nla_nest_end(skb, nest);
480
481 if (tcf_exts_dump_stats(skb, &r->exts) < 0)
482 goto nla_put_failure;
483 }
484
485 return skb->len;
486
487 nla_put_failure:
488 nlmsg_trim(skb, b);
489 return -1;
490 }
491
492 static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
493 .kind = "tcindex",
494 .classify = tcindex_classify,
495 .init = tcindex_init,
496 .destroy = tcindex_destroy,
497 .get = tcindex_get,
498 .put = tcindex_put,
499 .change = tcindex_change,
500 .delete = tcindex_delete,
501 .walk = tcindex_walk,
502 .dump = tcindex_dump,
503 .owner = THIS_MODULE,
504 };
505
506 static int __init init_tcindex(void)
507 {
508 return register_tcf_proto_ops(&cls_tcindex_ops);
509 }
510
511 static void __exit exit_tcindex(void)
512 {
513 unregister_tcf_proto_ops(&cls_tcindex_ops);
514 }
515
516 module_init(init_tcindex)
517 module_exit(exit_tcindex)
518 MODULE_LICENSE("GPL");
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