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