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Merge branch 'next/spring-cleaning' into next/cleanup
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / block / aoe / aoecmd.c
1 /* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
2 /*
3 * aoecmd.c
4 * Filesystem request handling methods
5 */
6
7 #include <linux/ata.h>
8 #include <linux/slab.h>
9 #include <linux/hdreg.h>
10 #include <linux/blkdev.h>
11 #include <linux/skbuff.h>
12 #include <linux/netdevice.h>
13 #include <linux/genhd.h>
14 #include <linux/moduleparam.h>
15 #include <linux/workqueue.h>
16 #include <linux/kthread.h>
17 #include <net/net_namespace.h>
18 #include <asm/unaligned.h>
19 #include <linux/uio.h>
20 #include "aoe.h"
21
22 #define MAXIOC (8192) /* default meant to avoid most soft lockups */
23
24 static void ktcomplete(struct frame *, struct sk_buff *);
25 static int count_targets(struct aoedev *d, int *untainted);
26
27 static struct buf *nextbuf(struct aoedev *);
28
29 static int aoe_deadsecs = 60 * 3;
30 module_param(aoe_deadsecs, int, 0644);
31 MODULE_PARM_DESC(aoe_deadsecs, "After aoe_deadsecs seconds, give up and fail dev.");
32
33 static int aoe_maxout = 64;
34 module_param(aoe_maxout, int, 0644);
35 MODULE_PARM_DESC(aoe_maxout,
36 "Only aoe_maxout outstanding packets for every MAC on eX.Y.");
37
38 static wait_queue_head_t ktiowq;
39 static struct ktstate kts;
40
41 /* io completion queue */
42 static struct {
43 struct list_head head;
44 spinlock_t lock;
45 } iocq;
46
47 static struct page *empty_page;
48
49 static struct sk_buff *
50 new_skb(ulong len)
51 {
52 struct sk_buff *skb;
53
54 skb = alloc_skb(len, GFP_ATOMIC);
55 if (skb) {
56 skb_reset_mac_header(skb);
57 skb_reset_network_header(skb);
58 skb->protocol = __constant_htons(ETH_P_AOE);
59 skb_checksum_none_assert(skb);
60 }
61 return skb;
62 }
63
64 static struct frame *
65 getframe_deferred(struct aoedev *d, u32 tag)
66 {
67 struct list_head *head, *pos, *nx;
68 struct frame *f;
69
70 head = &d->rexmitq;
71 list_for_each_safe(pos, nx, head) {
72 f = list_entry(pos, struct frame, head);
73 if (f->tag == tag) {
74 list_del(pos);
75 return f;
76 }
77 }
78 return NULL;
79 }
80
81 static struct frame *
82 getframe(struct aoedev *d, u32 tag)
83 {
84 struct frame *f;
85 struct list_head *head, *pos, *nx;
86 u32 n;
87
88 n = tag % NFACTIVE;
89 head = &d->factive[n];
90 list_for_each_safe(pos, nx, head) {
91 f = list_entry(pos, struct frame, head);
92 if (f->tag == tag) {
93 list_del(pos);
94 return f;
95 }
96 }
97 return NULL;
98 }
99
100 /*
101 * Leave the top bit clear so we have tagspace for userland.
102 * The bottom 16 bits are the xmit tick for rexmit/rttavg processing.
103 * This driver reserves tag -1 to mean "unused frame."
104 */
105 static int
106 newtag(struct aoedev *d)
107 {
108 register ulong n;
109
110 n = jiffies & 0xffff;
111 return n |= (++d->lasttag & 0x7fff) << 16;
112 }
113
114 static u32
115 aoehdr_atainit(struct aoedev *d, struct aoetgt *t, struct aoe_hdr *h)
116 {
117 u32 host_tag = newtag(d);
118
119 memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
120 memcpy(h->dst, t->addr, sizeof h->dst);
121 h->type = __constant_cpu_to_be16(ETH_P_AOE);
122 h->verfl = AOE_HVER;
123 h->major = cpu_to_be16(d->aoemajor);
124 h->minor = d->aoeminor;
125 h->cmd = AOECMD_ATA;
126 h->tag = cpu_to_be32(host_tag);
127
128 return host_tag;
129 }
130
131 static inline void
132 put_lba(struct aoe_atahdr *ah, sector_t lba)
133 {
134 ah->lba0 = lba;
135 ah->lba1 = lba >>= 8;
136 ah->lba2 = lba >>= 8;
137 ah->lba3 = lba >>= 8;
138 ah->lba4 = lba >>= 8;
139 ah->lba5 = lba >>= 8;
140 }
141
142 static struct aoeif *
143 ifrotate(struct aoetgt *t)
144 {
145 struct aoeif *ifp;
146
147 ifp = t->ifp;
148 ifp++;
149 if (ifp >= &t->ifs[NAOEIFS] || ifp->nd == NULL)
150 ifp = t->ifs;
151 if (ifp->nd == NULL)
152 return NULL;
153 return t->ifp = ifp;
154 }
155
156 static void
157 skb_pool_put(struct aoedev *d, struct sk_buff *skb)
158 {
159 __skb_queue_tail(&d->skbpool, skb);
160 }
161
162 static struct sk_buff *
163 skb_pool_get(struct aoedev *d)
164 {
165 struct sk_buff *skb = skb_peek(&d->skbpool);
166
167 if (skb && atomic_read(&skb_shinfo(skb)->dataref) == 1) {
168 __skb_unlink(skb, &d->skbpool);
169 return skb;
170 }
171 if (skb_queue_len(&d->skbpool) < NSKBPOOLMAX &&
172 (skb = new_skb(ETH_ZLEN)))
173 return skb;
174
175 return NULL;
176 }
177
178 void
179 aoe_freetframe(struct frame *f)
180 {
181 struct aoetgt *t;
182
183 t = f->t;
184 f->buf = NULL;
185 f->lba = 0;
186 f->bv = NULL;
187 f->r_skb = NULL;
188 f->flags = 0;
189 list_add(&f->head, &t->ffree);
190 }
191
192 static struct frame *
193 newtframe(struct aoedev *d, struct aoetgt *t)
194 {
195 struct frame *f;
196 struct sk_buff *skb;
197 struct list_head *pos;
198
199 if (list_empty(&t->ffree)) {
200 if (t->falloc >= NSKBPOOLMAX*2)
201 return NULL;
202 f = kcalloc(1, sizeof(*f), GFP_ATOMIC);
203 if (f == NULL)
204 return NULL;
205 t->falloc++;
206 f->t = t;
207 } else {
208 pos = t->ffree.next;
209 list_del(pos);
210 f = list_entry(pos, struct frame, head);
211 }
212
213 skb = f->skb;
214 if (skb == NULL) {
215 f->skb = skb = new_skb(ETH_ZLEN);
216 if (!skb) {
217 bail: aoe_freetframe(f);
218 return NULL;
219 }
220 }
221
222 if (atomic_read(&skb_shinfo(skb)->dataref) != 1) {
223 skb = skb_pool_get(d);
224 if (skb == NULL)
225 goto bail;
226 skb_pool_put(d, f->skb);
227 f->skb = skb;
228 }
229
230 skb->truesize -= skb->data_len;
231 skb_shinfo(skb)->nr_frags = skb->data_len = 0;
232 skb_trim(skb, 0);
233 return f;
234 }
235
236 static struct frame *
237 newframe(struct aoedev *d)
238 {
239 struct frame *f;
240 struct aoetgt *t, **tt;
241 int totout = 0;
242 int use_tainted;
243 int has_untainted;
244
245 if (!d->targets || !d->targets[0]) {
246 printk(KERN_ERR "aoe: NULL TARGETS!\n");
247 return NULL;
248 }
249 tt = d->tgt; /* last used target */
250 for (use_tainted = 0, has_untainted = 0;;) {
251 tt++;
252 if (tt >= &d->targets[d->ntargets] || !*tt)
253 tt = d->targets;
254 t = *tt;
255 if (!t->taint) {
256 has_untainted = 1;
257 totout += t->nout;
258 }
259 if (t->nout < t->maxout
260 && (use_tainted || !t->taint)
261 && t->ifp->nd) {
262 f = newtframe(d, t);
263 if (f) {
264 ifrotate(t);
265 d->tgt = tt;
266 return f;
267 }
268 }
269 if (tt == d->tgt) { /* we've looped and found nada */
270 if (!use_tainted && !has_untainted)
271 use_tainted = 1;
272 else
273 break;
274 }
275 }
276 if (totout == 0) {
277 d->kicked++;
278 d->flags |= DEVFL_KICKME;
279 }
280 return NULL;
281 }
282
283 static void
284 skb_fillup(struct sk_buff *skb, struct bio_vec *bv, ulong off, ulong cnt)
285 {
286 int frag = 0;
287 ulong fcnt;
288 loop:
289 fcnt = bv->bv_len - (off - bv->bv_offset);
290 if (fcnt > cnt)
291 fcnt = cnt;
292 skb_fill_page_desc(skb, frag++, bv->bv_page, off, fcnt);
293 cnt -= fcnt;
294 if (cnt <= 0)
295 return;
296 bv++;
297 off = bv->bv_offset;
298 goto loop;
299 }
300
301 static void
302 fhash(struct frame *f)
303 {
304 struct aoedev *d = f->t->d;
305 u32 n;
306
307 n = f->tag % NFACTIVE;
308 list_add_tail(&f->head, &d->factive[n]);
309 }
310
311 static void
312 ata_rw_frameinit(struct frame *f)
313 {
314 struct aoetgt *t;
315 struct aoe_hdr *h;
316 struct aoe_atahdr *ah;
317 struct sk_buff *skb;
318 char writebit, extbit;
319
320 skb = f->skb;
321 h = (struct aoe_hdr *) skb_mac_header(skb);
322 ah = (struct aoe_atahdr *) (h + 1);
323 skb_put(skb, sizeof(*h) + sizeof(*ah));
324 memset(h, 0, skb->len);
325
326 writebit = 0x10;
327 extbit = 0x4;
328
329 t = f->t;
330 f->tag = aoehdr_atainit(t->d, t, h);
331 fhash(f);
332 t->nout++;
333 f->waited = 0;
334 f->waited_total = 0;
335 if (f->buf)
336 f->lba = f->buf->sector;
337
338 /* set up ata header */
339 ah->scnt = f->bcnt >> 9;
340 put_lba(ah, f->lba);
341 if (t->d->flags & DEVFL_EXT) {
342 ah->aflags |= AOEAFL_EXT;
343 } else {
344 extbit = 0;
345 ah->lba3 &= 0x0f;
346 ah->lba3 |= 0xe0; /* LBA bit + obsolete 0xa0 */
347 }
348 if (f->buf && bio_data_dir(f->buf->bio) == WRITE) {
349 skb_fillup(skb, f->bv, f->bv_off, f->bcnt);
350 ah->aflags |= AOEAFL_WRITE;
351 skb->len += f->bcnt;
352 skb->data_len = f->bcnt;
353 skb->truesize += f->bcnt;
354 t->wpkts++;
355 } else {
356 t->rpkts++;
357 writebit = 0;
358 }
359
360 ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
361 skb->dev = t->ifp->nd;
362 }
363
364 static int
365 aoecmd_ata_rw(struct aoedev *d)
366 {
367 struct frame *f;
368 struct buf *buf;
369 struct aoetgt *t;
370 struct sk_buff *skb;
371 struct sk_buff_head queue;
372 ulong bcnt, fbcnt;
373
374 buf = nextbuf(d);
375 if (buf == NULL)
376 return 0;
377 f = newframe(d);
378 if (f == NULL)
379 return 0;
380 t = *d->tgt;
381 bcnt = d->maxbcnt;
382 if (bcnt == 0)
383 bcnt = DEFAULTBCNT;
384 if (bcnt > buf->resid)
385 bcnt = buf->resid;
386 fbcnt = bcnt;
387 f->bv = buf->bv;
388 f->bv_off = f->bv->bv_offset + (f->bv->bv_len - buf->bv_resid);
389 do {
390 if (fbcnt < buf->bv_resid) {
391 buf->bv_resid -= fbcnt;
392 buf->resid -= fbcnt;
393 break;
394 }
395 fbcnt -= buf->bv_resid;
396 buf->resid -= buf->bv_resid;
397 if (buf->resid == 0) {
398 d->ip.buf = NULL;
399 break;
400 }
401 buf->bv++;
402 buf->bv_resid = buf->bv->bv_len;
403 WARN_ON(buf->bv_resid == 0);
404 } while (fbcnt);
405
406 /* initialize the headers & frame */
407 f->buf = buf;
408 f->bcnt = bcnt;
409 ata_rw_frameinit(f);
410
411 /* mark all tracking fields and load out */
412 buf->nframesout += 1;
413 buf->sector += bcnt >> 9;
414
415 skb = skb_clone(f->skb, GFP_ATOMIC);
416 if (skb) {
417 do_gettimeofday(&f->sent);
418 f->sent_jiffs = (u32) jiffies;
419 __skb_queue_head_init(&queue);
420 __skb_queue_tail(&queue, skb);
421 aoenet_xmit(&queue);
422 }
423 return 1;
424 }
425
426 /* some callers cannot sleep, and they can call this function,
427 * transmitting the packets later, when interrupts are on
428 */
429 static void
430 aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff_head *queue)
431 {
432 struct aoe_hdr *h;
433 struct aoe_cfghdr *ch;
434 struct sk_buff *skb;
435 struct net_device *ifp;
436
437 rcu_read_lock();
438 for_each_netdev_rcu(&init_net, ifp) {
439 dev_hold(ifp);
440 if (!is_aoe_netif(ifp))
441 goto cont;
442
443 skb = new_skb(sizeof *h + sizeof *ch);
444 if (skb == NULL) {
445 printk(KERN_INFO "aoe: skb alloc failure\n");
446 goto cont;
447 }
448 skb_put(skb, sizeof *h + sizeof *ch);
449 skb->dev = ifp;
450 __skb_queue_tail(queue, skb);
451 h = (struct aoe_hdr *) skb_mac_header(skb);
452 memset(h, 0, sizeof *h + sizeof *ch);
453
454 memset(h->dst, 0xff, sizeof h->dst);
455 memcpy(h->src, ifp->dev_addr, sizeof h->src);
456 h->type = __constant_cpu_to_be16(ETH_P_AOE);
457 h->verfl = AOE_HVER;
458 h->major = cpu_to_be16(aoemajor);
459 h->minor = aoeminor;
460 h->cmd = AOECMD_CFG;
461
462 cont:
463 dev_put(ifp);
464 }
465 rcu_read_unlock();
466 }
467
468 static void
469 resend(struct aoedev *d, struct frame *f)
470 {
471 struct sk_buff *skb;
472 struct sk_buff_head queue;
473 struct aoe_hdr *h;
474 struct aoe_atahdr *ah;
475 struct aoetgt *t;
476 char buf[128];
477 u32 n;
478
479 t = f->t;
480 n = newtag(d);
481 skb = f->skb;
482 if (ifrotate(t) == NULL) {
483 /* probably can't happen, but set it up to fail anyway */
484 pr_info("aoe: resend: no interfaces to rotate to.\n");
485 ktcomplete(f, NULL);
486 return;
487 }
488 h = (struct aoe_hdr *) skb_mac_header(skb);
489 ah = (struct aoe_atahdr *) (h+1);
490
491 if (!(f->flags & FFL_PROBE)) {
492 snprintf(buf, sizeof(buf),
493 "%15s e%ld.%d oldtag=%08x@%08lx newtag=%08x s=%pm d=%pm nout=%d\n",
494 "retransmit", d->aoemajor, d->aoeminor,
495 f->tag, jiffies, n,
496 h->src, h->dst, t->nout);
497 aoechr_error(buf);
498 }
499
500 f->tag = n;
501 fhash(f);
502 h->tag = cpu_to_be32(n);
503 memcpy(h->dst, t->addr, sizeof h->dst);
504 memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
505
506 skb->dev = t->ifp->nd;
507 skb = skb_clone(skb, GFP_ATOMIC);
508 if (skb == NULL)
509 return;
510 do_gettimeofday(&f->sent);
511 f->sent_jiffs = (u32) jiffies;
512 __skb_queue_head_init(&queue);
513 __skb_queue_tail(&queue, skb);
514 aoenet_xmit(&queue);
515 }
516
517 static int
518 tsince_hr(struct frame *f)
519 {
520 struct timeval now;
521 int n;
522
523 do_gettimeofday(&now);
524 n = now.tv_usec - f->sent.tv_usec;
525 n += (now.tv_sec - f->sent.tv_sec) * USEC_PER_SEC;
526
527 if (n < 0)
528 n = -n;
529
530 /* For relatively long periods, use jiffies to avoid
531 * discrepancies caused by updates to the system time.
532 *
533 * On system with HZ of 1000, 32-bits is over 49 days
534 * worth of jiffies, or over 71 minutes worth of usecs.
535 *
536 * Jiffies overflow is handled by subtraction of unsigned ints:
537 * (gdb) print (unsigned) 2 - (unsigned) 0xfffffffe
538 * $3 = 4
539 * (gdb)
540 */
541 if (n > USEC_PER_SEC / 4) {
542 n = ((u32) jiffies) - f->sent_jiffs;
543 n *= USEC_PER_SEC / HZ;
544 }
545
546 return n;
547 }
548
549 static int
550 tsince(u32 tag)
551 {
552 int n;
553
554 n = jiffies & 0xffff;
555 n -= tag & 0xffff;
556 if (n < 0)
557 n += 1<<16;
558 return jiffies_to_usecs(n + 1);
559 }
560
561 static struct aoeif *
562 getif(struct aoetgt *t, struct net_device *nd)
563 {
564 struct aoeif *p, *e;
565
566 p = t->ifs;
567 e = p + NAOEIFS;
568 for (; p < e; p++)
569 if (p->nd == nd)
570 return p;
571 return NULL;
572 }
573
574 static void
575 ejectif(struct aoetgt *t, struct aoeif *ifp)
576 {
577 struct aoeif *e;
578 struct net_device *nd;
579 ulong n;
580
581 nd = ifp->nd;
582 e = t->ifs + NAOEIFS - 1;
583 n = (e - ifp) * sizeof *ifp;
584 memmove(ifp, ifp+1, n);
585 e->nd = NULL;
586 dev_put(nd);
587 }
588
589 static struct frame *
590 reassign_frame(struct frame *f)
591 {
592 struct frame *nf;
593 struct sk_buff *skb;
594
595 nf = newframe(f->t->d);
596 if (!nf)
597 return NULL;
598 if (nf->t == f->t) {
599 aoe_freetframe(nf);
600 return NULL;
601 }
602
603 skb = nf->skb;
604 nf->skb = f->skb;
605 nf->buf = f->buf;
606 nf->bcnt = f->bcnt;
607 nf->lba = f->lba;
608 nf->bv = f->bv;
609 nf->bv_off = f->bv_off;
610 nf->waited = 0;
611 nf->waited_total = f->waited_total;
612 nf->sent = f->sent;
613 nf->sent_jiffs = f->sent_jiffs;
614 f->skb = skb;
615
616 return nf;
617 }
618
619 static void
620 probe(struct aoetgt *t)
621 {
622 struct aoedev *d;
623 struct frame *f;
624 struct sk_buff *skb;
625 struct sk_buff_head queue;
626 size_t n, m;
627 int frag;
628
629 d = t->d;
630 f = newtframe(d, t);
631 if (!f) {
632 pr_err("%s %pm for e%ld.%d: %s\n",
633 "aoe: cannot probe remote address",
634 t->addr,
635 (long) d->aoemajor, d->aoeminor,
636 "no frame available");
637 return;
638 }
639 f->flags |= FFL_PROBE;
640 ifrotate(t);
641 f->bcnt = t->d->maxbcnt ? t->d->maxbcnt : DEFAULTBCNT;
642 ata_rw_frameinit(f);
643 skb = f->skb;
644 for (frag = 0, n = f->bcnt; n > 0; ++frag, n -= m) {
645 if (n < PAGE_SIZE)
646 m = n;
647 else
648 m = PAGE_SIZE;
649 skb_fill_page_desc(skb, frag, empty_page, 0, m);
650 }
651 skb->len += f->bcnt;
652 skb->data_len = f->bcnt;
653 skb->truesize += f->bcnt;
654
655 skb = skb_clone(f->skb, GFP_ATOMIC);
656 if (skb) {
657 do_gettimeofday(&f->sent);
658 f->sent_jiffs = (u32) jiffies;
659 __skb_queue_head_init(&queue);
660 __skb_queue_tail(&queue, skb);
661 aoenet_xmit(&queue);
662 }
663 }
664
665 static long
666 rto(struct aoedev *d)
667 {
668 long t;
669
670 t = 2 * d->rttavg >> RTTSCALE;
671 t += 8 * d->rttdev >> RTTDSCALE;
672 if (t == 0)
673 t = 1;
674
675 return t;
676 }
677
678 static void
679 rexmit_deferred(struct aoedev *d)
680 {
681 struct aoetgt *t;
682 struct frame *f;
683 struct frame *nf;
684 struct list_head *pos, *nx, *head;
685 int since;
686 int untainted;
687
688 count_targets(d, &untainted);
689
690 head = &d->rexmitq;
691 list_for_each_safe(pos, nx, head) {
692 f = list_entry(pos, struct frame, head);
693 t = f->t;
694 if (t->taint) {
695 if (!(f->flags & FFL_PROBE)) {
696 nf = reassign_frame(f);
697 if (nf) {
698 if (t->nout_probes == 0
699 && untainted > 0) {
700 probe(t);
701 t->nout_probes++;
702 }
703 list_replace(&f->head, &nf->head);
704 pos = &nf->head;
705 aoe_freetframe(f);
706 f = nf;
707 t = f->t;
708 }
709 } else if (untainted < 1) {
710 /* don't probe w/o other untainted aoetgts */
711 goto stop_probe;
712 } else if (tsince_hr(f) < t->taint * rto(d)) {
713 /* reprobe slowly when taint is high */
714 continue;
715 }
716 } else if (f->flags & FFL_PROBE) {
717 stop_probe: /* don't probe untainted aoetgts */
718 list_del(pos);
719 aoe_freetframe(f);
720 /* leaving d->kicked, because this is routine */
721 f->t->d->flags |= DEVFL_KICKME;
722 continue;
723 }
724 if (t->nout >= t->maxout)
725 continue;
726 list_del(pos);
727 t->nout++;
728 if (f->flags & FFL_PROBE)
729 t->nout_probes++;
730 since = tsince_hr(f);
731 f->waited += since;
732 f->waited_total += since;
733 resend(d, f);
734 }
735 }
736
737 /* An aoetgt accumulates demerits quickly, and successful
738 * probing redeems the aoetgt slowly.
739 */
740 static void
741 scorn(struct aoetgt *t)
742 {
743 int n;
744
745 n = t->taint++;
746 t->taint += t->taint * 2;
747 if (n > t->taint)
748 t->taint = n;
749 if (t->taint > MAX_TAINT)
750 t->taint = MAX_TAINT;
751 }
752
753 static int
754 count_targets(struct aoedev *d, int *untainted)
755 {
756 int i, good;
757
758 for (i = good = 0; i < d->ntargets && d->targets[i]; ++i)
759 if (d->targets[i]->taint == 0)
760 good++;
761
762 if (untainted)
763 *untainted = good;
764 return i;
765 }
766
767 static void
768 rexmit_timer(ulong vp)
769 {
770 struct aoedev *d;
771 struct aoetgt *t;
772 struct aoeif *ifp;
773 struct frame *f;
774 struct list_head *head, *pos, *nx;
775 LIST_HEAD(flist);
776 register long timeout;
777 ulong flags, n;
778 int i;
779 int utgts; /* number of aoetgt descriptors (not slots) */
780 int since;
781
782 d = (struct aoedev *) vp;
783
784 spin_lock_irqsave(&d->lock, flags);
785
786 /* timeout based on observed timings and variations */
787 timeout = rto(d);
788
789 utgts = count_targets(d, NULL);
790
791 if (d->flags & DEVFL_TKILL) {
792 spin_unlock_irqrestore(&d->lock, flags);
793 return;
794 }
795
796 /* collect all frames to rexmit into flist */
797 for (i = 0; i < NFACTIVE; i++) {
798 head = &d->factive[i];
799 list_for_each_safe(pos, nx, head) {
800 f = list_entry(pos, struct frame, head);
801 if (tsince_hr(f) < timeout)
802 break; /* end of expired frames */
803 /* move to flist for later processing */
804 list_move_tail(pos, &flist);
805 }
806 }
807
808 /* process expired frames */
809 while (!list_empty(&flist)) {
810 pos = flist.next;
811 f = list_entry(pos, struct frame, head);
812 since = tsince_hr(f);
813 n = f->waited_total + since;
814 n /= USEC_PER_SEC;
815 if (aoe_deadsecs
816 && n > aoe_deadsecs
817 && !(f->flags & FFL_PROBE)) {
818 /* Waited too long. Device failure.
819 * Hang all frames on first hash bucket for downdev
820 * to clean up.
821 */
822 list_splice(&flist, &d->factive[0]);
823 aoedev_downdev(d);
824 goto out;
825 }
826
827 t = f->t;
828 n = f->waited + since;
829 n /= USEC_PER_SEC;
830 if (aoe_deadsecs && utgts > 0
831 && (n > aoe_deadsecs / utgts || n > HARD_SCORN_SECS))
832 scorn(t); /* avoid this target */
833
834 if (t->maxout != 1) {
835 t->ssthresh = t->maxout / 2;
836 t->maxout = 1;
837 }
838
839 if (f->flags & FFL_PROBE) {
840 t->nout_probes--;
841 } else {
842 ifp = getif(t, f->skb->dev);
843 if (ifp && ++ifp->lost > (t->nframes << 1)
844 && (ifp != t->ifs || t->ifs[1].nd)) {
845 ejectif(t, ifp);
846 ifp = NULL;
847 }
848 }
849 list_move_tail(pos, &d->rexmitq);
850 t->nout--;
851 }
852 rexmit_deferred(d);
853
854 out:
855 if ((d->flags & DEVFL_KICKME) && d->blkq) {
856 d->flags &= ~DEVFL_KICKME;
857 d->blkq->request_fn(d->blkq);
858 }
859
860 d->timer.expires = jiffies + TIMERTICK;
861 add_timer(&d->timer);
862
863 spin_unlock_irqrestore(&d->lock, flags);
864 }
865
866 static unsigned long
867 rqbiocnt(struct request *r)
868 {
869 struct bio *bio;
870 unsigned long n = 0;
871
872 __rq_for_each_bio(bio, r)
873 n++;
874 return n;
875 }
876
877 /* This can be removed if we are certain that no users of the block
878 * layer will ever use zero-count pages in bios. Otherwise we have to
879 * protect against the put_page sometimes done by the network layer.
880 *
881 * See http://oss.sgi.com/archives/xfs/2007-01/msg00594.html for
882 * discussion.
883 *
884 * We cannot use get_page in the workaround, because it insists on a
885 * positive page count as a precondition. So we use _count directly.
886 */
887 static void
888 bio_pageinc(struct bio *bio)
889 {
890 struct bio_vec *bv;
891 struct page *page;
892 int i;
893
894 bio_for_each_segment(bv, bio, i) {
895 page = bv->bv_page;
896 /* Non-zero page count for non-head members of
897 * compound pages is no longer allowed by the kernel,
898 * but this has never been seen here.
899 */
900 if (unlikely(PageCompound(page)))
901 if (compound_trans_head(page) != page) {
902 pr_crit("page tail used for block I/O\n");
903 BUG();
904 }
905 atomic_inc(&page->_count);
906 }
907 }
908
909 static void
910 bio_pagedec(struct bio *bio)
911 {
912 struct bio_vec *bv;
913 int i;
914
915 bio_for_each_segment(bv, bio, i)
916 atomic_dec(&bv->bv_page->_count);
917 }
918
919 static void
920 bufinit(struct buf *buf, struct request *rq, struct bio *bio)
921 {
922 struct bio_vec *bv;
923
924 memset(buf, 0, sizeof(*buf));
925 buf->rq = rq;
926 buf->bio = bio;
927 buf->resid = bio->bi_size;
928 buf->sector = bio->bi_sector;
929 bio_pageinc(bio);
930 buf->bv = bv = &bio->bi_io_vec[bio->bi_idx];
931 buf->bv_resid = bv->bv_len;
932 WARN_ON(buf->bv_resid == 0);
933 }
934
935 static struct buf *
936 nextbuf(struct aoedev *d)
937 {
938 struct request *rq;
939 struct request_queue *q;
940 struct buf *buf;
941 struct bio *bio;
942
943 q = d->blkq;
944 if (q == NULL)
945 return NULL; /* initializing */
946 if (d->ip.buf)
947 return d->ip.buf;
948 rq = d->ip.rq;
949 if (rq == NULL) {
950 rq = blk_peek_request(q);
951 if (rq == NULL)
952 return NULL;
953 blk_start_request(rq);
954 d->ip.rq = rq;
955 d->ip.nxbio = rq->bio;
956 rq->special = (void *) rqbiocnt(rq);
957 }
958 buf = mempool_alloc(d->bufpool, GFP_ATOMIC);
959 if (buf == NULL) {
960 pr_err("aoe: nextbuf: unable to mempool_alloc!\n");
961 return NULL;
962 }
963 bio = d->ip.nxbio;
964 bufinit(buf, rq, bio);
965 bio = bio->bi_next;
966 d->ip.nxbio = bio;
967 if (bio == NULL)
968 d->ip.rq = NULL;
969 return d->ip.buf = buf;
970 }
971
972 /* enters with d->lock held */
973 void
974 aoecmd_work(struct aoedev *d)
975 {
976 rexmit_deferred(d);
977 while (aoecmd_ata_rw(d))
978 ;
979 }
980
981 /* this function performs work that has been deferred until sleeping is OK
982 */
983 void
984 aoecmd_sleepwork(struct work_struct *work)
985 {
986 struct aoedev *d = container_of(work, struct aoedev, work);
987 struct block_device *bd;
988 u64 ssize;
989
990 if (d->flags & DEVFL_GDALLOC)
991 aoeblk_gdalloc(d);
992
993 if (d->flags & DEVFL_NEWSIZE) {
994 ssize = get_capacity(d->gd);
995 bd = bdget_disk(d->gd, 0);
996 if (bd) {
997 mutex_lock(&bd->bd_inode->i_mutex);
998 i_size_write(bd->bd_inode, (loff_t)ssize<<9);
999 mutex_unlock(&bd->bd_inode->i_mutex);
1000 bdput(bd);
1001 }
1002 spin_lock_irq(&d->lock);
1003 d->flags |= DEVFL_UP;
1004 d->flags &= ~DEVFL_NEWSIZE;
1005 spin_unlock_irq(&d->lock);
1006 }
1007 }
1008
1009 static void
1010 ata_ident_fixstring(u16 *id, int ns)
1011 {
1012 u16 s;
1013
1014 while (ns-- > 0) {
1015 s = *id;
1016 *id++ = s >> 8 | s << 8;
1017 }
1018 }
1019
1020 static void
1021 ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
1022 {
1023 u64 ssize;
1024 u16 n;
1025
1026 /* word 83: command set supported */
1027 n = get_unaligned_le16(&id[83 << 1]);
1028
1029 /* word 86: command set/feature enabled */
1030 n |= get_unaligned_le16(&id[86 << 1]);
1031
1032 if (n & (1<<10)) { /* bit 10: LBA 48 */
1033 d->flags |= DEVFL_EXT;
1034
1035 /* word 100: number lba48 sectors */
1036 ssize = get_unaligned_le64(&id[100 << 1]);
1037
1038 /* set as in ide-disk.c:init_idedisk_capacity */
1039 d->geo.cylinders = ssize;
1040 d->geo.cylinders /= (255 * 63);
1041 d->geo.heads = 255;
1042 d->geo.sectors = 63;
1043 } else {
1044 d->flags &= ~DEVFL_EXT;
1045
1046 /* number lba28 sectors */
1047 ssize = get_unaligned_le32(&id[60 << 1]);
1048
1049 /* NOTE: obsolete in ATA 6 */
1050 d->geo.cylinders = get_unaligned_le16(&id[54 << 1]);
1051 d->geo.heads = get_unaligned_le16(&id[55 << 1]);
1052 d->geo.sectors = get_unaligned_le16(&id[56 << 1]);
1053 }
1054
1055 ata_ident_fixstring((u16 *) &id[10<<1], 10); /* serial */
1056 ata_ident_fixstring((u16 *) &id[23<<1], 4); /* firmware */
1057 ata_ident_fixstring((u16 *) &id[27<<1], 20); /* model */
1058 memcpy(d->ident, id, sizeof(d->ident));
1059
1060 if (d->ssize != ssize)
1061 printk(KERN_INFO
1062 "aoe: %pm e%ld.%d v%04x has %llu sectors\n",
1063 t->addr,
1064 d->aoemajor, d->aoeminor,
1065 d->fw_ver, (long long)ssize);
1066 d->ssize = ssize;
1067 d->geo.start = 0;
1068 if (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
1069 return;
1070 if (d->gd != NULL) {
1071 set_capacity(d->gd, ssize);
1072 d->flags |= DEVFL_NEWSIZE;
1073 } else
1074 d->flags |= DEVFL_GDALLOC;
1075 schedule_work(&d->work);
1076 }
1077
1078 static void
1079 calc_rttavg(struct aoedev *d, struct aoetgt *t, int rtt)
1080 {
1081 register long n;
1082
1083 n = rtt;
1084
1085 /* cf. Congestion Avoidance and Control, Jacobson & Karels, 1988 */
1086 n -= d->rttavg >> RTTSCALE;
1087 d->rttavg += n;
1088 if (n < 0)
1089 n = -n;
1090 n -= d->rttdev >> RTTDSCALE;
1091 d->rttdev += n;
1092
1093 if (!t || t->maxout >= t->nframes)
1094 return;
1095 if (t->maxout < t->ssthresh)
1096 t->maxout += 1;
1097 else if (t->nout == t->maxout && t->next_cwnd-- == 0) {
1098 t->maxout += 1;
1099 t->next_cwnd = t->maxout;
1100 }
1101 }
1102
1103 static struct aoetgt *
1104 gettgt(struct aoedev *d, char *addr)
1105 {
1106 struct aoetgt **t, **e;
1107
1108 t = d->targets;
1109 e = t + d->ntargets;
1110 for (; t < e && *t; t++)
1111 if (memcmp((*t)->addr, addr, sizeof((*t)->addr)) == 0)
1112 return *t;
1113 return NULL;
1114 }
1115
1116 static void
1117 bvcpy(struct bio_vec *bv, ulong off, struct sk_buff *skb, long cnt)
1118 {
1119 ulong fcnt;
1120 char *p;
1121 int soff = 0;
1122 loop:
1123 fcnt = bv->bv_len - (off - bv->bv_offset);
1124 if (fcnt > cnt)
1125 fcnt = cnt;
1126 p = page_address(bv->bv_page) + off;
1127 skb_copy_bits(skb, soff, p, fcnt);
1128 soff += fcnt;
1129 cnt -= fcnt;
1130 if (cnt <= 0)
1131 return;
1132 bv++;
1133 off = bv->bv_offset;
1134 goto loop;
1135 }
1136
1137 void
1138 aoe_end_request(struct aoedev *d, struct request *rq, int fastfail)
1139 {
1140 struct bio *bio;
1141 int bok;
1142 struct request_queue *q;
1143
1144 q = d->blkq;
1145 if (rq == d->ip.rq)
1146 d->ip.rq = NULL;
1147 do {
1148 bio = rq->bio;
1149 bok = !fastfail && test_bit(BIO_UPTODATE, &bio->bi_flags);
1150 } while (__blk_end_request(rq, bok ? 0 : -EIO, bio->bi_size));
1151
1152 /* cf. http://lkml.org/lkml/2006/10/31/28 */
1153 if (!fastfail)
1154 __blk_run_queue(q);
1155 }
1156
1157 static void
1158 aoe_end_buf(struct aoedev *d, struct buf *buf)
1159 {
1160 struct request *rq;
1161 unsigned long n;
1162
1163 if (buf == d->ip.buf)
1164 d->ip.buf = NULL;
1165 rq = buf->rq;
1166 bio_pagedec(buf->bio);
1167 mempool_free(buf, d->bufpool);
1168 n = (unsigned long) rq->special;
1169 rq->special = (void *) --n;
1170 if (n == 0)
1171 aoe_end_request(d, rq, 0);
1172 }
1173
1174 static void
1175 ktiocomplete(struct frame *f)
1176 {
1177 struct aoe_hdr *hin, *hout;
1178 struct aoe_atahdr *ahin, *ahout;
1179 struct buf *buf;
1180 struct sk_buff *skb;
1181 struct aoetgt *t;
1182 struct aoeif *ifp;
1183 struct aoedev *d;
1184 long n;
1185 int untainted;
1186
1187 if (f == NULL)
1188 return;
1189
1190 t = f->t;
1191 d = t->d;
1192 skb = f->r_skb;
1193 buf = f->buf;
1194 if (f->flags & FFL_PROBE)
1195 goto out;
1196 if (!skb) /* just fail the buf. */
1197 goto noskb;
1198
1199 hout = (struct aoe_hdr *) skb_mac_header(f->skb);
1200 ahout = (struct aoe_atahdr *) (hout+1);
1201
1202 hin = (struct aoe_hdr *) skb->data;
1203 skb_pull(skb, sizeof(*hin));
1204 ahin = (struct aoe_atahdr *) skb->data;
1205 skb_pull(skb, sizeof(*ahin));
1206 if (ahin->cmdstat & 0xa9) { /* these bits cleared on success */
1207 pr_err("aoe: ata error cmd=%2.2Xh stat=%2.2Xh from e%ld.%d\n",
1208 ahout->cmdstat, ahin->cmdstat,
1209 d->aoemajor, d->aoeminor);
1210 noskb: if (buf)
1211 clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
1212 goto out;
1213 }
1214
1215 n = ahout->scnt << 9;
1216 switch (ahout->cmdstat) {
1217 case ATA_CMD_PIO_READ:
1218 case ATA_CMD_PIO_READ_EXT:
1219 if (skb->len < n) {
1220 pr_err("%s e%ld.%d. skb->len=%d need=%ld\n",
1221 "aoe: runt data size in read from",
1222 (long) d->aoemajor, d->aoeminor,
1223 skb->len, n);
1224 clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
1225 break;
1226 }
1227 bvcpy(f->bv, f->bv_off, skb, n);
1228 case ATA_CMD_PIO_WRITE:
1229 case ATA_CMD_PIO_WRITE_EXT:
1230 spin_lock_irq(&d->lock);
1231 ifp = getif(t, skb->dev);
1232 if (ifp)
1233 ifp->lost = 0;
1234 spin_unlock_irq(&d->lock);
1235 break;
1236 case ATA_CMD_ID_ATA:
1237 if (skb->len < 512) {
1238 pr_info("%s e%ld.%d. skb->len=%d need=512\n",
1239 "aoe: runt data size in ataid from",
1240 (long) d->aoemajor, d->aoeminor,
1241 skb->len);
1242 break;
1243 }
1244 if (skb_linearize(skb))
1245 break;
1246 spin_lock_irq(&d->lock);
1247 ataid_complete(d, t, skb->data);
1248 spin_unlock_irq(&d->lock);
1249 break;
1250 default:
1251 pr_info("aoe: unrecognized ata command %2.2Xh for %d.%d\n",
1252 ahout->cmdstat,
1253 be16_to_cpu(get_unaligned(&hin->major)),
1254 hin->minor);
1255 }
1256 out:
1257 spin_lock_irq(&d->lock);
1258 if (t->taint > 0
1259 && --t->taint > 0
1260 && t->nout_probes == 0) {
1261 count_targets(d, &untainted);
1262 if (untainted > 0) {
1263 probe(t);
1264 t->nout_probes++;
1265 }
1266 }
1267
1268 aoe_freetframe(f);
1269
1270 if (buf && --buf->nframesout == 0 && buf->resid == 0)
1271 aoe_end_buf(d, buf);
1272
1273 spin_unlock_irq(&d->lock);
1274 aoedev_put(d);
1275 dev_kfree_skb(skb);
1276 }
1277
1278 /* Enters with iocq.lock held.
1279 * Returns true iff responses needing processing remain.
1280 */
1281 static int
1282 ktio(void)
1283 {
1284 struct frame *f;
1285 struct list_head *pos;
1286 int i;
1287
1288 for (i = 0; ; ++i) {
1289 if (i == MAXIOC)
1290 return 1;
1291 if (list_empty(&iocq.head))
1292 return 0;
1293 pos = iocq.head.next;
1294 list_del(pos);
1295 spin_unlock_irq(&iocq.lock);
1296 f = list_entry(pos, struct frame, head);
1297 ktiocomplete(f);
1298 spin_lock_irq(&iocq.lock);
1299 }
1300 }
1301
1302 static int
1303 kthread(void *vp)
1304 {
1305 struct ktstate *k;
1306 DECLARE_WAITQUEUE(wait, current);
1307 int more;
1308
1309 k = vp;
1310 current->flags |= PF_NOFREEZE;
1311 set_user_nice(current, -10);
1312 complete(&k->rendez); /* tell spawner we're running */
1313 do {
1314 spin_lock_irq(k->lock);
1315 more = k->fn();
1316 if (!more) {
1317 add_wait_queue(k->waitq, &wait);
1318 __set_current_state(TASK_INTERRUPTIBLE);
1319 }
1320 spin_unlock_irq(k->lock);
1321 if (!more) {
1322 schedule();
1323 remove_wait_queue(k->waitq, &wait);
1324 } else
1325 cond_resched();
1326 } while (!kthread_should_stop());
1327 complete(&k->rendez); /* tell spawner we're stopping */
1328 return 0;
1329 }
1330
1331 void
1332 aoe_ktstop(struct ktstate *k)
1333 {
1334 kthread_stop(k->task);
1335 wait_for_completion(&k->rendez);
1336 }
1337
1338 int
1339 aoe_ktstart(struct ktstate *k)
1340 {
1341 struct task_struct *task;
1342
1343 init_completion(&k->rendez);
1344 task = kthread_run(kthread, k, k->name);
1345 if (task == NULL || IS_ERR(task))
1346 return -ENOMEM;
1347 k->task = task;
1348 wait_for_completion(&k->rendez); /* allow kthread to start */
1349 init_completion(&k->rendez); /* for waiting for exit later */
1350 return 0;
1351 }
1352
1353 /* pass it off to kthreads for processing */
1354 static void
1355 ktcomplete(struct frame *f, struct sk_buff *skb)
1356 {
1357 ulong flags;
1358
1359 f->r_skb = skb;
1360 spin_lock_irqsave(&iocq.lock, flags);
1361 list_add_tail(&f->head, &iocq.head);
1362 spin_unlock_irqrestore(&iocq.lock, flags);
1363 wake_up(&ktiowq);
1364 }
1365
1366 struct sk_buff *
1367 aoecmd_ata_rsp(struct sk_buff *skb)
1368 {
1369 struct aoedev *d;
1370 struct aoe_hdr *h;
1371 struct frame *f;
1372 u32 n;
1373 ulong flags;
1374 char ebuf[128];
1375 u16 aoemajor;
1376
1377 h = (struct aoe_hdr *) skb->data;
1378 aoemajor = be16_to_cpu(get_unaligned(&h->major));
1379 d = aoedev_by_aoeaddr(aoemajor, h->minor, 0);
1380 if (d == NULL) {
1381 snprintf(ebuf, sizeof ebuf, "aoecmd_ata_rsp: ata response "
1382 "for unknown device %d.%d\n",
1383 aoemajor, h->minor);
1384 aoechr_error(ebuf);
1385 return skb;
1386 }
1387
1388 spin_lock_irqsave(&d->lock, flags);
1389
1390 n = be32_to_cpu(get_unaligned(&h->tag));
1391 f = getframe(d, n);
1392 if (f) {
1393 calc_rttavg(d, f->t, tsince_hr(f));
1394 f->t->nout--;
1395 if (f->flags & FFL_PROBE)
1396 f->t->nout_probes--;
1397 } else {
1398 f = getframe_deferred(d, n);
1399 if (f) {
1400 calc_rttavg(d, NULL, tsince_hr(f));
1401 } else {
1402 calc_rttavg(d, NULL, tsince(n));
1403 spin_unlock_irqrestore(&d->lock, flags);
1404 aoedev_put(d);
1405 snprintf(ebuf, sizeof(ebuf),
1406 "%15s e%d.%d tag=%08x@%08lx s=%pm d=%pm\n",
1407 "unexpected rsp",
1408 get_unaligned_be16(&h->major),
1409 h->minor,
1410 get_unaligned_be32(&h->tag),
1411 jiffies,
1412 h->src,
1413 h->dst);
1414 aoechr_error(ebuf);
1415 return skb;
1416 }
1417 }
1418 aoecmd_work(d);
1419
1420 spin_unlock_irqrestore(&d->lock, flags);
1421
1422 ktcomplete(f, skb);
1423
1424 /*
1425 * Note here that we do not perform an aoedev_put, as we are
1426 * leaving this reference for the ktio to release.
1427 */
1428 return NULL;
1429 }
1430
1431 void
1432 aoecmd_cfg(ushort aoemajor, unsigned char aoeminor)
1433 {
1434 struct sk_buff_head queue;
1435
1436 __skb_queue_head_init(&queue);
1437 aoecmd_cfg_pkts(aoemajor, aoeminor, &queue);
1438 aoenet_xmit(&queue);
1439 }
1440
1441 struct sk_buff *
1442 aoecmd_ata_id(struct aoedev *d)
1443 {
1444 struct aoe_hdr *h;
1445 struct aoe_atahdr *ah;
1446 struct frame *f;
1447 struct sk_buff *skb;
1448 struct aoetgt *t;
1449
1450 f = newframe(d);
1451 if (f == NULL)
1452 return NULL;
1453
1454 t = *d->tgt;
1455
1456 /* initialize the headers & frame */
1457 skb = f->skb;
1458 h = (struct aoe_hdr *) skb_mac_header(skb);
1459 ah = (struct aoe_atahdr *) (h+1);
1460 skb_put(skb, sizeof *h + sizeof *ah);
1461 memset(h, 0, skb->len);
1462 f->tag = aoehdr_atainit(d, t, h);
1463 fhash(f);
1464 t->nout++;
1465 f->waited = 0;
1466 f->waited_total = 0;
1467
1468 /* set up ata header */
1469 ah->scnt = 1;
1470 ah->cmdstat = ATA_CMD_ID_ATA;
1471 ah->lba3 = 0xa0;
1472
1473 skb->dev = t->ifp->nd;
1474
1475 d->rttavg = RTTAVG_INIT;
1476 d->rttdev = RTTDEV_INIT;
1477 d->timer.function = rexmit_timer;
1478
1479 skb = skb_clone(skb, GFP_ATOMIC);
1480 if (skb) {
1481 do_gettimeofday(&f->sent);
1482 f->sent_jiffs = (u32) jiffies;
1483 }
1484
1485 return skb;
1486 }
1487
1488 static struct aoetgt **
1489 grow_targets(struct aoedev *d)
1490 {
1491 ulong oldn, newn;
1492 struct aoetgt **tt;
1493
1494 oldn = d->ntargets;
1495 newn = oldn * 2;
1496 tt = kcalloc(newn, sizeof(*d->targets), GFP_ATOMIC);
1497 if (!tt)
1498 return NULL;
1499 memmove(tt, d->targets, sizeof(*d->targets) * oldn);
1500 d->tgt = tt + (d->tgt - d->targets);
1501 kfree(d->targets);
1502 d->targets = tt;
1503 d->ntargets = newn;
1504
1505 return &d->targets[oldn];
1506 }
1507
1508 static struct aoetgt *
1509 addtgt(struct aoedev *d, char *addr, ulong nframes)
1510 {
1511 struct aoetgt *t, **tt, **te;
1512
1513 tt = d->targets;
1514 te = tt + d->ntargets;
1515 for (; tt < te && *tt; tt++)
1516 ;
1517
1518 if (tt == te) {
1519 tt = grow_targets(d);
1520 if (!tt)
1521 goto nomem;
1522 }
1523 t = kzalloc(sizeof(*t), GFP_ATOMIC);
1524 if (!t)
1525 goto nomem;
1526 t->nframes = nframes;
1527 t->d = d;
1528 memcpy(t->addr, addr, sizeof t->addr);
1529 t->ifp = t->ifs;
1530 aoecmd_wreset(t);
1531 t->maxout = t->nframes / 2;
1532 INIT_LIST_HEAD(&t->ffree);
1533 return *tt = t;
1534
1535 nomem:
1536 pr_info("aoe: cannot allocate memory to add target\n");
1537 return NULL;
1538 }
1539
1540 static void
1541 setdbcnt(struct aoedev *d)
1542 {
1543 struct aoetgt **t, **e;
1544 int bcnt = 0;
1545
1546 t = d->targets;
1547 e = t + d->ntargets;
1548 for (; t < e && *t; t++)
1549 if (bcnt == 0 || bcnt > (*t)->minbcnt)
1550 bcnt = (*t)->minbcnt;
1551 if (bcnt != d->maxbcnt) {
1552 d->maxbcnt = bcnt;
1553 pr_info("aoe: e%ld.%d: setting %d byte data frames\n",
1554 d->aoemajor, d->aoeminor, bcnt);
1555 }
1556 }
1557
1558 static void
1559 setifbcnt(struct aoetgt *t, struct net_device *nd, int bcnt)
1560 {
1561 struct aoedev *d;
1562 struct aoeif *p, *e;
1563 int minbcnt;
1564
1565 d = t->d;
1566 minbcnt = bcnt;
1567 p = t->ifs;
1568 e = p + NAOEIFS;
1569 for (; p < e; p++) {
1570 if (p->nd == NULL)
1571 break; /* end of the valid interfaces */
1572 if (p->nd == nd) {
1573 p->bcnt = bcnt; /* we're updating */
1574 nd = NULL;
1575 } else if (minbcnt > p->bcnt)
1576 minbcnt = p->bcnt; /* find the min interface */
1577 }
1578 if (nd) {
1579 if (p == e) {
1580 pr_err("aoe: device setifbcnt failure; too many interfaces.\n");
1581 return;
1582 }
1583 dev_hold(nd);
1584 p->nd = nd;
1585 p->bcnt = bcnt;
1586 }
1587 t->minbcnt = minbcnt;
1588 setdbcnt(d);
1589 }
1590
1591 void
1592 aoecmd_cfg_rsp(struct sk_buff *skb)
1593 {
1594 struct aoedev *d;
1595 struct aoe_hdr *h;
1596 struct aoe_cfghdr *ch;
1597 struct aoetgt *t;
1598 ulong flags, aoemajor;
1599 struct sk_buff *sl;
1600 struct sk_buff_head queue;
1601 u16 n;
1602
1603 sl = NULL;
1604 h = (struct aoe_hdr *) skb_mac_header(skb);
1605 ch = (struct aoe_cfghdr *) (h+1);
1606
1607 /*
1608 * Enough people have their dip switches set backwards to
1609 * warrant a loud message for this special case.
1610 */
1611 aoemajor = get_unaligned_be16(&h->major);
1612 if (aoemajor == 0xfff) {
1613 printk(KERN_ERR "aoe: Warning: shelf address is all ones. "
1614 "Check shelf dip switches.\n");
1615 return;
1616 }
1617 if (aoemajor == 0xffff) {
1618 pr_info("aoe: e%ld.%d: broadcast shelf number invalid\n",
1619 aoemajor, (int) h->minor);
1620 return;
1621 }
1622 if (h->minor == 0xff) {
1623 pr_info("aoe: e%ld.%d: broadcast slot number invalid\n",
1624 aoemajor, (int) h->minor);
1625 return;
1626 }
1627
1628 n = be16_to_cpu(ch->bufcnt);
1629 if (n > aoe_maxout) /* keep it reasonable */
1630 n = aoe_maxout;
1631
1632 d = aoedev_by_aoeaddr(aoemajor, h->minor, 1);
1633 if (d == NULL) {
1634 pr_info("aoe: device allocation failure\n");
1635 return;
1636 }
1637
1638 spin_lock_irqsave(&d->lock, flags);
1639
1640 t = gettgt(d, h->src);
1641 if (t) {
1642 t->nframes = n;
1643 if (n < t->maxout)
1644 aoecmd_wreset(t);
1645 } else {
1646 t = addtgt(d, h->src, n);
1647 if (!t)
1648 goto bail;
1649 }
1650 n = skb->dev->mtu;
1651 n -= sizeof(struct aoe_hdr) + sizeof(struct aoe_atahdr);
1652 n /= 512;
1653 if (n > ch->scnt)
1654 n = ch->scnt;
1655 n = n ? n * 512 : DEFAULTBCNT;
1656 setifbcnt(t, skb->dev, n);
1657
1658 /* don't change users' perspective */
1659 if (d->nopen == 0) {
1660 d->fw_ver = be16_to_cpu(ch->fwver);
1661 sl = aoecmd_ata_id(d);
1662 }
1663 bail:
1664 spin_unlock_irqrestore(&d->lock, flags);
1665 aoedev_put(d);
1666 if (sl) {
1667 __skb_queue_head_init(&queue);
1668 __skb_queue_tail(&queue, sl);
1669 aoenet_xmit(&queue);
1670 }
1671 }
1672
1673 void
1674 aoecmd_wreset(struct aoetgt *t)
1675 {
1676 t->maxout = 1;
1677 t->ssthresh = t->nframes / 2;
1678 t->next_cwnd = t->nframes;
1679 }
1680
1681 void
1682 aoecmd_cleanslate(struct aoedev *d)
1683 {
1684 struct aoetgt **t, **te;
1685
1686 d->rttavg = RTTAVG_INIT;
1687 d->rttdev = RTTDEV_INIT;
1688 d->maxbcnt = 0;
1689
1690 t = d->targets;
1691 te = t + d->ntargets;
1692 for (; t < te && *t; t++)
1693 aoecmd_wreset(*t);
1694 }
1695
1696 void
1697 aoe_failbuf(struct aoedev *d, struct buf *buf)
1698 {
1699 if (buf == NULL)
1700 return;
1701 buf->resid = 0;
1702 clear_bit(BIO_UPTODATE, &buf->bio->bi_flags);
1703 if (buf->nframesout == 0)
1704 aoe_end_buf(d, buf);
1705 }
1706
1707 void
1708 aoe_flush_iocq(void)
1709 {
1710 struct frame *f;
1711 struct aoedev *d;
1712 LIST_HEAD(flist);
1713 struct list_head *pos;
1714 struct sk_buff *skb;
1715 ulong flags;
1716
1717 spin_lock_irqsave(&iocq.lock, flags);
1718 list_splice_init(&iocq.head, &flist);
1719 spin_unlock_irqrestore(&iocq.lock, flags);
1720 while (!list_empty(&flist)) {
1721 pos = flist.next;
1722 list_del(pos);
1723 f = list_entry(pos, struct frame, head);
1724 d = f->t->d;
1725 skb = f->r_skb;
1726 spin_lock_irqsave(&d->lock, flags);
1727 if (f->buf) {
1728 f->buf->nframesout--;
1729 aoe_failbuf(d, f->buf);
1730 }
1731 aoe_freetframe(f);
1732 spin_unlock_irqrestore(&d->lock, flags);
1733 dev_kfree_skb(skb);
1734 aoedev_put(d);
1735 }
1736 }
1737
1738 int __init
1739 aoecmd_init(void)
1740 {
1741 void *p;
1742
1743 /* get_zeroed_page returns page with ref count 1 */
1744 p = (void *) get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
1745 if (!p)
1746 return -ENOMEM;
1747 empty_page = virt_to_page(p);
1748
1749 INIT_LIST_HEAD(&iocq.head);
1750 spin_lock_init(&iocq.lock);
1751 init_waitqueue_head(&ktiowq);
1752 kts.name = "aoe_ktio";
1753 kts.fn = ktio;
1754 kts.waitq = &ktiowq;
1755 kts.lock = &iocq.lock;
1756 return aoe_ktstart(&kts);
1757 }
1758
1759 void
1760 aoecmd_exit(void)
1761 {
1762 aoe_ktstop(&kts);
1763 aoe_flush_iocq();
1764
1765 free_page((unsigned long) page_address(empty_page));
1766 empty_page = NULL;
1767 }
kernel source for telekom puls (alcatel/mediatek)