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tools, slub: Fix off-by-one buffer corruption after readlink() call
[linux-2.6/linux-mips.git] / arch / sparc / kernel / ldc.c
blob732b0bce6001c887f1ce4ad850691d4b3a112033
1 /* ldc.c: Logical Domain Channel link-layer protocol driver.
2 *
3 * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/delay.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/scatterlist.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/init.h>
17 #include <linux/bitmap.h>
18
19 #include <asm/hypervisor.h>
20 #include <asm/iommu.h>
21 #include <asm/page.h>
22 #include <asm/ldc.h>
23 #include <asm/mdesc.h>
24
25 #define DRV_MODULE_NAME "ldc"
26 #define PFX DRV_MODULE_NAME ": "
27 #define DRV_MODULE_VERSION "1.1"
28 #define DRV_MODULE_RELDATE "July 22, 2008"
29
30 static char version[] __devinitdata =
31 DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
32 #define LDC_PACKET_SIZE 64
33
34 /* Packet header layout for unreliable and reliable mode frames.
35 * When in RAW mode, packets are simply straight 64-byte payloads
36 * with no headers.
37 */
38 struct ldc_packet {
39 u8 type;
40 #define LDC_CTRL 0x01
41 #define LDC_DATA 0x02
42 #define LDC_ERR 0x10
43
44 u8 stype;
45 #define LDC_INFO 0x01
46 #define LDC_ACK 0x02
47 #define LDC_NACK 0x04
48
49 u8 ctrl;
50 #define LDC_VERS 0x01 /* Link Version */
51 #define LDC_RTS 0x02 /* Request To Send */
52 #define LDC_RTR 0x03 /* Ready To Receive */
53 #define LDC_RDX 0x04 /* Ready for Data eXchange */
54 #define LDC_CTRL_MSK 0x0f
55
56 u8 env;
57 #define LDC_LEN 0x3f
58 #define LDC_FRAG_MASK 0xc0
59 #define LDC_START 0x40
60 #define LDC_STOP 0x80
61
62 u32 seqid;
63
64 union {
65 u8 u_data[LDC_PACKET_SIZE - 8];
66 struct {
67 u32 pad;
68 u32 ackid;
69 u8 r_data[LDC_PACKET_SIZE - 8 - 8];
70 } r;
71 } u;
72 };
73
74 struct ldc_version {
75 u16 major;
76 u16 minor;
77 };
78
79 /* Ordered from largest major to lowest. */
80 static struct ldc_version ver_arr[] = {
81 { .major = 1, .minor = 0 },
82 };
83
84 #define LDC_DEFAULT_MTU (4 * LDC_PACKET_SIZE)
85 #define LDC_DEFAULT_NUM_ENTRIES (PAGE_SIZE / LDC_PACKET_SIZE)
86
87 struct ldc_channel;
88
89 struct ldc_mode_ops {
90 int (*write)(struct ldc_channel *, const void *, unsigned int);
91 int (*read)(struct ldc_channel *, void *, unsigned int);
92 };
93
94 static const struct ldc_mode_ops raw_ops;
95 static const struct ldc_mode_ops nonraw_ops;
96 static const struct ldc_mode_ops stream_ops;
97
98 int ldom_domaining_enabled;
99
100 struct ldc_iommu {
101 /* Protects arena alloc/free. */
102 spinlock_t lock;
103 struct iommu_arena arena;
104 struct ldc_mtable_entry *page_table;
105 };
106
107 struct ldc_channel {
108 /* Protects all operations that depend upon channel state. */
109 spinlock_t lock;
110
111 unsigned long id;
112
113 u8 *mssbuf;
114 u32 mssbuf_len;
115 u32 mssbuf_off;
116
117 struct ldc_packet *tx_base;
118 unsigned long tx_head;
119 unsigned long tx_tail;
120 unsigned long tx_num_entries;
121 unsigned long tx_ra;
122
123 unsigned long tx_acked;
124
125 struct ldc_packet *rx_base;
126 unsigned long rx_head;
127 unsigned long rx_tail;
128 unsigned long rx_num_entries;
129 unsigned long rx_ra;
130
131 u32 rcv_nxt;
132 u32 snd_nxt;
133
134 unsigned long chan_state;
135
136 struct ldc_channel_config cfg;
137 void *event_arg;
138
139 const struct ldc_mode_ops *mops;
140
141 struct ldc_iommu iommu;
142
143 struct ldc_version ver;
144
145 u8 hs_state;
146 #define LDC_HS_CLOSED 0x00
147 #define LDC_HS_OPEN 0x01
148 #define LDC_HS_GOTVERS 0x02
149 #define LDC_HS_SENTRTR 0x03
150 #define LDC_HS_GOTRTR 0x04
151 #define LDC_HS_COMPLETE 0x10
152
153 u8 flags;
154 #define LDC_FLAG_ALLOCED_QUEUES 0x01
155 #define LDC_FLAG_REGISTERED_QUEUES 0x02
156 #define LDC_FLAG_REGISTERED_IRQS 0x04
157 #define LDC_FLAG_RESET 0x10
158
159 u8 mss;
160 u8 state;
161
162 #define LDC_IRQ_NAME_MAX 32
163 char rx_irq_name[LDC_IRQ_NAME_MAX];
164 char tx_irq_name[LDC_IRQ_NAME_MAX];
165
166 struct hlist_head mh_list;
167
168 struct hlist_node list;
169 };
170
171 #define ldcdbg(TYPE, f, a...) \
172 do { if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
173 printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
174 } while (0)
175
176 static const char *state_to_str(u8 state)
177 {
178 switch (state) {
179 case LDC_STATE_INVALID:
180 return "INVALID";
181 case LDC_STATE_INIT:
182 return "INIT";
183 case LDC_STATE_BOUND:
184 return "BOUND";
185 case LDC_STATE_READY:
186 return "READY";
187 case LDC_STATE_CONNECTED:
188 return "CONNECTED";
189 default:
190 return "<UNKNOWN>";
191 }
192 }
193
194 static void ldc_set_state(struct ldc_channel *lp, u8 state)
195 {
196 ldcdbg(STATE, "STATE (%s) --> (%s)\n",
197 state_to_str(lp->state),
198 state_to_str(state));
199
200 lp->state = state;
201 }
202
203 static unsigned long __advance(unsigned long off, unsigned long num_entries)
204 {
205 off += LDC_PACKET_SIZE;
206 if (off == (num_entries * LDC_PACKET_SIZE))
207 off = 0;
208
209 return off;
210 }
211
212 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
213 {
214 return __advance(off, lp->rx_num_entries);
215 }
216
217 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
218 {
219 return __advance(off, lp->tx_num_entries);
220 }
221
222 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
223 unsigned long *new_tail)
224 {
225 struct ldc_packet *p;
226 unsigned long t;
227
228 t = tx_advance(lp, lp->tx_tail);
229 if (t == lp->tx_head)
230 return NULL;
231
232 *new_tail = t;
233
234 p = lp->tx_base;
235 return p + (lp->tx_tail / LDC_PACKET_SIZE);
236 }
237
238 /* When we are in reliable or stream mode, have to track the next packet
239 * we haven't gotten an ACK for in the TX queue using tx_acked. We have
240 * to be careful not to stomp over the queue past that point. During
241 * the handshake, we don't have TX data packets pending in the queue
242 * and that's why handshake_get_tx_packet() need not be mindful of
243 * lp->tx_acked.
244 */
245 static unsigned long head_for_data(struct ldc_channel *lp)
246 {
247 if (lp->cfg.mode == LDC_MODE_STREAM)
248 return lp->tx_acked;
249 return lp->tx_head;
250 }
251
252 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
253 {
254 unsigned long limit, tail, new_tail, diff;
255 unsigned int mss;
256
257 limit = head_for_data(lp);
258 tail = lp->tx_tail;
259 new_tail = tx_advance(lp, tail);
260 if (new_tail == limit)
261 return 0;
262
263 if (limit > new_tail)
264 diff = limit - new_tail;
265 else
266 diff = (limit +
267 ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
268 diff /= LDC_PACKET_SIZE;
269 mss = lp->mss;
270
271 if (diff * mss < size)
272 return 0;
273
274 return 1;
275 }
276
277 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
278 unsigned long *new_tail)
279 {
280 struct ldc_packet *p;
281 unsigned long h, t;
282
283 h = head_for_data(lp);
284 t = tx_advance(lp, lp->tx_tail);
285 if (t == h)
286 return NULL;
287
288 *new_tail = t;
289
290 p = lp->tx_base;
291 return p + (lp->tx_tail / LDC_PACKET_SIZE);
292 }
293
294 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
295 {
296 unsigned long orig_tail = lp->tx_tail;
297 int limit = 1000;
298
299 lp->tx_tail = tail;
300 while (limit-- > 0) {
301 unsigned long err;
302
303 err = sun4v_ldc_tx_set_qtail(lp->id, tail);
304 if (!err)
305 return 0;
306
307 if (err != HV_EWOULDBLOCK) {
308 lp->tx_tail = orig_tail;
309 return -EINVAL;
310 }
311 udelay(1);
312 }
313
314 lp->tx_tail = orig_tail;
315 return -EBUSY;
316 }
317
318 /* This just updates the head value in the hypervisor using
319 * a polling loop with a timeout. The caller takes care of
320 * upating software state representing the head change, if any.
321 */
322 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
323 {
324 int limit = 1000;
325
326 while (limit-- > 0) {
327 unsigned long err;
328
329 err = sun4v_ldc_rx_set_qhead(lp->id, head);
330 if (!err)
331 return 0;
332
333 if (err != HV_EWOULDBLOCK)
334 return -EINVAL;
335
336 udelay(1);
337 }
338
339 return -EBUSY;
340 }
341
342 static int send_tx_packet(struct ldc_channel *lp,
343 struct ldc_packet *p,
344 unsigned long new_tail)
345 {
346 BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
347
348 return set_tx_tail(lp, new_tail);
349 }
350
351 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
352 u8 stype, u8 ctrl,
353 void *data, int dlen,
354 unsigned long *new_tail)
355 {
356 struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
357
358 if (p) {
359 memset(p, 0, sizeof(*p));
360 p->type = LDC_CTRL;
361 p->stype = stype;
362 p->ctrl = ctrl;
363 if (data)
364 memcpy(p->u.u_data, data, dlen);
365 }
366 return p;
367 }
368
369 static int start_handshake(struct ldc_channel *lp)
370 {
371 struct ldc_packet *p;
372 struct ldc_version *ver;
373 unsigned long new_tail;
374
375 ver = &ver_arr[0];
376
377 ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
378 ver->major, ver->minor);
379
380 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
381 ver, sizeof(*ver), &new_tail);
382 if (p) {
383 int err = send_tx_packet(lp, p, new_tail);
384 if (!err)
385 lp->flags &= ~LDC_FLAG_RESET;
386 return err;
387 }
388 return -EBUSY;
389 }
390
391 static int send_version_nack(struct ldc_channel *lp,
392 u16 major, u16 minor)
393 {
394 struct ldc_packet *p;
395 struct ldc_version ver;
396 unsigned long new_tail;
397
398 ver.major = major;
399 ver.minor = minor;
400
401 p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
402 &ver, sizeof(ver), &new_tail);
403 if (p) {
404 ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
405 ver.major, ver.minor);
406
407 return send_tx_packet(lp, p, new_tail);
408 }
409 return -EBUSY;
410 }
411
412 static int send_version_ack(struct ldc_channel *lp,
413 struct ldc_version *vp)
414 {
415 struct ldc_packet *p;
416 unsigned long new_tail;
417
418 p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
419 vp, sizeof(*vp), &new_tail);
420 if (p) {
421 ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
422 vp->major, vp->minor);
423
424 return send_tx_packet(lp, p, new_tail);
425 }
426 return -EBUSY;
427 }
428
429 static int send_rts(struct ldc_channel *lp)
430 {
431 struct ldc_packet *p;
432 unsigned long new_tail;
433
434 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
435 &new_tail);
436 if (p) {
437 p->env = lp->cfg.mode;
438 p->seqid = 0;
439 lp->rcv_nxt = 0;
440
441 ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
442 p->env, p->seqid);
443
444 return send_tx_packet(lp, p, new_tail);
445 }
446 return -EBUSY;
447 }
448
449 static int send_rtr(struct ldc_channel *lp)
450 {
451 struct ldc_packet *p;
452 unsigned long new_tail;
453
454 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
455 &new_tail);
456 if (p) {
457 p->env = lp->cfg.mode;
458 p->seqid = 0;
459
460 ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
461 p->env, p->seqid);
462
463 return send_tx_packet(lp, p, new_tail);
464 }
465 return -EBUSY;
466 }
467
468 static int send_rdx(struct ldc_channel *lp)
469 {
470 struct ldc_packet *p;
471 unsigned long new_tail;
472
473 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
474 &new_tail);
475 if (p) {
476 p->env = 0;
477 p->seqid = ++lp->snd_nxt;
478 p->u.r.ackid = lp->rcv_nxt;
479
480 ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
481 p->env, p->seqid, p->u.r.ackid);
482
483 return send_tx_packet(lp, p, new_tail);
484 }
485 return -EBUSY;
486 }
487
488 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
489 {
490 struct ldc_packet *p;
491 unsigned long new_tail;
492 int err;
493
494 p = data_get_tx_packet(lp, &new_tail);
495 if (!p)
496 return -EBUSY;
497 memset(p, 0, sizeof(*p));
498 p->type = data_pkt->type;
499 p->stype = LDC_NACK;
500 p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
501 p->seqid = lp->snd_nxt + 1;
502 p->u.r.ackid = lp->rcv_nxt;
503
504 ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
505 p->type, p->ctrl, p->seqid, p->u.r.ackid);
506
507 err = send_tx_packet(lp, p, new_tail);
508 if (!err)
509 lp->snd_nxt++;
510
511 return err;
512 }
513
514 static int ldc_abort(struct ldc_channel *lp)
515 {
516 unsigned long hv_err;
517
518 ldcdbg(STATE, "ABORT\n");
519
520 /* We report but do not act upon the hypervisor errors because
521 * there really isn't much we can do if they fail at this point.
522 */
523 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
524 if (hv_err)
525 printk(KERN_ERR PFX "ldc_abort: "
526 "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
527 lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
528
529 hv_err = sun4v_ldc_tx_get_state(lp->id,
530 &lp->tx_head,
531 &lp->tx_tail,
532 &lp->chan_state);
533 if (hv_err)
534 printk(KERN_ERR PFX "ldc_abort: "
535 "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
536 lp->id, hv_err);
537
538 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
539 if (hv_err)
540 printk(KERN_ERR PFX "ldc_abort: "
541 "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
542 lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
543
544 /* Refetch the RX queue state as well, because we could be invoked
545 * here in the queue processing context.
546 */
547 hv_err = sun4v_ldc_rx_get_state(lp->id,
548 &lp->rx_head,
549 &lp->rx_tail,
550 &lp->chan_state);
551 if (hv_err)
552 printk(KERN_ERR PFX "ldc_abort: "
553 "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
554 lp->id, hv_err);
555
556 return -ECONNRESET;
557 }
558
559 static struct ldc_version *find_by_major(u16 major)
560 {
561 struct ldc_version *ret = NULL;
562 int i;
563
564 for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
565 struct ldc_version *v = &ver_arr[i];
566 if (v->major <= major) {
567 ret = v;
568 break;
569 }
570 }
571 return ret;
572 }
573
574 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
575 {
576 struct ldc_version *vap;
577 int err;
578
579 ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
580 vp->major, vp->minor);
581
582 if (lp->hs_state == LDC_HS_GOTVERS) {
583 lp->hs_state = LDC_HS_OPEN;
584 memset(&lp->ver, 0, sizeof(lp->ver));
585 }
586
587 vap = find_by_major(vp->major);
588 if (!vap) {
589 err = send_version_nack(lp, 0, 0);
590 } else if (vap->major != vp->major) {
591 err = send_version_nack(lp, vap->major, vap->minor);
592 } else {
593 struct ldc_version ver = *vp;
594 if (ver.minor > vap->minor)
595 ver.minor = vap->minor;
596 err = send_version_ack(lp, &ver);
597 if (!err) {
598 lp->ver = ver;
599 lp->hs_state = LDC_HS_GOTVERS;
600 }
601 }
602 if (err)
603 return ldc_abort(lp);
604
605 return 0;
606 }
607
608 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
609 {
610 ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
611 vp->major, vp->minor);
612
613 if (lp->hs_state == LDC_HS_GOTVERS) {
614 if (lp->ver.major != vp->major ||
615 lp->ver.minor != vp->minor)
616 return ldc_abort(lp);
617 } else {
618 lp->ver = *vp;
619 lp->hs_state = LDC_HS_GOTVERS;
620 }
621 if (send_rts(lp))
622 return ldc_abort(lp);
623 return 0;
624 }
625
626 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
627 {
628 struct ldc_version *vap;
629 struct ldc_packet *p;
630 unsigned long new_tail;
631
632 if (vp->major == 0 && vp->minor == 0)
633 return ldc_abort(lp);
634
635 vap = find_by_major(vp->major);
636 if (!vap)
637 return ldc_abort(lp);
638
639 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
640 vap, sizeof(*vap),
641 &new_tail);
642 if (!p)
643 return ldc_abort(lp);
644
645 return send_tx_packet(lp, p, new_tail);
646 }
647
648 static int process_version(struct ldc_channel *lp,
649 struct ldc_packet *p)
650 {
651 struct ldc_version *vp;
652
653 vp = (struct ldc_version *) p->u.u_data;
654
655 switch (p->stype) {
656 case LDC_INFO:
657 return process_ver_info(lp, vp);
658
659 case LDC_ACK:
660 return process_ver_ack(lp, vp);
661
662 case LDC_NACK:
663 return process_ver_nack(lp, vp);
664
665 default:
666 return ldc_abort(lp);
667 }
668 }
669
670 static int process_rts(struct ldc_channel *lp,
671 struct ldc_packet *p)
672 {
673 ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
674 p->stype, p->seqid, p->env);
675
676 if (p->stype != LDC_INFO ||
677 lp->hs_state != LDC_HS_GOTVERS ||
678 p->env != lp->cfg.mode)
679 return ldc_abort(lp);
680
681 lp->snd_nxt = p->seqid;
682 lp->rcv_nxt = p->seqid;
683 lp->hs_state = LDC_HS_SENTRTR;
684 if (send_rtr(lp))
685 return ldc_abort(lp);
686
687 return 0;
688 }
689
690 static int process_rtr(struct ldc_channel *lp,
691 struct ldc_packet *p)
692 {
693 ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
694 p->stype, p->seqid, p->env);
695
696 if (p->stype != LDC_INFO ||
697 p->env != lp->cfg.mode)
698 return ldc_abort(lp);
699
700 lp->snd_nxt = p->seqid;
701 lp->hs_state = LDC_HS_COMPLETE;
702 ldc_set_state(lp, LDC_STATE_CONNECTED);
703 send_rdx(lp);
704
705 return LDC_EVENT_UP;
706 }
707
708 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
709 {
710 return lp->rcv_nxt + 1 == seqid;
711 }
712
713 static int process_rdx(struct ldc_channel *lp,
714 struct ldc_packet *p)
715 {
716 ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
717 p->stype, p->seqid, p->env, p->u.r.ackid);
718
719 if (p->stype != LDC_INFO ||
720 !(rx_seq_ok(lp, p->seqid)))
721 return ldc_abort(lp);
722
723 lp->rcv_nxt = p->seqid;
724
725 lp->hs_state = LDC_HS_COMPLETE;
726 ldc_set_state(lp, LDC_STATE_CONNECTED);
727
728 return LDC_EVENT_UP;
729 }
730
731 static int process_control_frame(struct ldc_channel *lp,
732 struct ldc_packet *p)
733 {
734 switch (p->ctrl) {
735 case LDC_VERS:
736 return process_version(lp, p);
737
738 case LDC_RTS:
739 return process_rts(lp, p);
740
741 case LDC_RTR:
742 return process_rtr(lp, p);
743
744 case LDC_RDX:
745 return process_rdx(lp, p);
746
747 default:
748 return ldc_abort(lp);
749 }
750 }
751
752 static int process_error_frame(struct ldc_channel *lp,
753 struct ldc_packet *p)
754 {
755 return ldc_abort(lp);
756 }
757
758 static int process_data_ack(struct ldc_channel *lp,
759 struct ldc_packet *ack)
760 {
761 unsigned long head = lp->tx_acked;
762 u32 ackid = ack->u.r.ackid;
763
764 while (1) {
765 struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
766
767 head = tx_advance(lp, head);
768
769 if (p->seqid == ackid) {
770 lp->tx_acked = head;
771 return 0;
772 }
773 if (head == lp->tx_tail)
774 return ldc_abort(lp);
775 }
776
777 return 0;
778 }
779
780 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
781 {
782 if (event_mask & LDC_EVENT_RESET)
783 lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
784 if (event_mask & LDC_EVENT_UP)
785 lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
786 if (event_mask & LDC_EVENT_DATA_READY)
787 lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
788 }
789
790 static irqreturn_t ldc_rx(int irq, void *dev_id)
791 {
792 struct ldc_channel *lp = dev_id;
793 unsigned long orig_state, flags;
794 unsigned int event_mask;
795
796 spin_lock_irqsave(&lp->lock, flags);
797
798 orig_state = lp->chan_state;
799
800 /* We should probably check for hypervisor errors here and
801 * reset the LDC channel if we get one.
802 */
803 sun4v_ldc_rx_get_state(lp->id,
804 &lp->rx_head,
805 &lp->rx_tail,
806 &lp->chan_state);
807
808 ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
809 orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
810
811 event_mask = 0;
812
813 if (lp->cfg.mode == LDC_MODE_RAW &&
814 lp->chan_state == LDC_CHANNEL_UP) {
815 lp->hs_state = LDC_HS_COMPLETE;
816 ldc_set_state(lp, LDC_STATE_CONNECTED);
817
818 event_mask |= LDC_EVENT_UP;
819
820 orig_state = lp->chan_state;
821 }
822
823 /* If we are in reset state, flush the RX queue and ignore
824 * everything.
825 */
826 if (lp->flags & LDC_FLAG_RESET) {
827 (void) __set_rx_head(lp, lp->rx_tail);
828 goto out;
829 }
830
831 /* Once we finish the handshake, we let the ldc_read()
832 * paths do all of the control frame and state management.
833 * Just trigger the callback.
834 */
835 if (lp->hs_state == LDC_HS_COMPLETE) {
836 handshake_complete:
837 if (lp->chan_state != orig_state) {
838 unsigned int event = LDC_EVENT_RESET;
839
840 if (lp->chan_state == LDC_CHANNEL_UP)
841 event = LDC_EVENT_UP;
842
843 event_mask |= event;
844 }
845 if (lp->rx_head != lp->rx_tail)
846 event_mask |= LDC_EVENT_DATA_READY;
847
848 goto out;
849 }
850
851 if (lp->chan_state != orig_state)
852 goto out;
853
854 while (lp->rx_head != lp->rx_tail) {
855 struct ldc_packet *p;
856 unsigned long new;
857 int err;
858
859 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
860
861 switch (p->type) {
862 case LDC_CTRL:
863 err = process_control_frame(lp, p);
864 if (err > 0)
865 event_mask |= err;
866 break;
867
868 case LDC_DATA:
869 event_mask |= LDC_EVENT_DATA_READY;
870 err = 0;
871 break;
872
873 case LDC_ERR:
874 err = process_error_frame(lp, p);
875 break;
876
877 default:
878 err = ldc_abort(lp);
879 break;
880 }
881
882 if (err < 0)
883 break;
884
885 new = lp->rx_head;
886 new += LDC_PACKET_SIZE;
887 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
888 new = 0;
889 lp->rx_head = new;
890
891 err = __set_rx_head(lp, new);
892 if (err < 0) {
893 (void) ldc_abort(lp);
894 break;
895 }
896 if (lp->hs_state == LDC_HS_COMPLETE)
897 goto handshake_complete;
898 }
899
900 out:
901 spin_unlock_irqrestore(&lp->lock, flags);
902
903 send_events(lp, event_mask);
904
905 return IRQ_HANDLED;
906 }
907
908 static irqreturn_t ldc_tx(int irq, void *dev_id)
909 {
910 struct ldc_channel *lp = dev_id;
911 unsigned long flags, orig_state;
912 unsigned int event_mask = 0;
913
914 spin_lock_irqsave(&lp->lock, flags);
915
916 orig_state = lp->chan_state;
917
918 /* We should probably check for hypervisor errors here and
919 * reset the LDC channel if we get one.
920 */
921 sun4v_ldc_tx_get_state(lp->id,
922 &lp->tx_head,
923 &lp->tx_tail,
924 &lp->chan_state);
925
926 ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
927 orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
928
929 if (lp->cfg.mode == LDC_MODE_RAW &&
930 lp->chan_state == LDC_CHANNEL_UP) {
931 lp->hs_state = LDC_HS_COMPLETE;
932 ldc_set_state(lp, LDC_STATE_CONNECTED);
933
934 event_mask |= LDC_EVENT_UP;
935 }
936
937 spin_unlock_irqrestore(&lp->lock, flags);
938
939 send_events(lp, event_mask);
940
941 return IRQ_HANDLED;
942 }
943
944 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
945 * XXX that addition and removal from the ldc_channel_list has
946 * XXX atomicity, otherwise the __ldc_channel_exists() check is
947 * XXX totally pointless as another thread can slip into ldc_alloc()
948 * XXX and add a channel with the same ID. There also needs to be
949 * XXX a spinlock for ldc_channel_list.
950 */
951 static HLIST_HEAD(ldc_channel_list);
952
953 static int __ldc_channel_exists(unsigned long id)
954 {
955 struct ldc_channel *lp;
956 struct hlist_node *n;
957
958 hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
959 if (lp->id == id)
960 return 1;
961 }
962 return 0;
963 }
964
965 static int alloc_queue(const char *name, unsigned long num_entries,
966 struct ldc_packet **base, unsigned long *ra)
967 {
968 unsigned long size, order;
969 void *q;
970
971 size = num_entries * LDC_PACKET_SIZE;
972 order = get_order(size);
973
974 q = (void *) __get_free_pages(GFP_KERNEL, order);
975 if (!q) {
976 printk(KERN_ERR PFX "Alloc of %s queue failed with "
977 "size=%lu order=%lu\n", name, size, order);
978 return -ENOMEM;
979 }
980
981 memset(q, 0, PAGE_SIZE << order);
982
983 *base = q;
984 *ra = __pa(q);
985
986 return 0;
987 }
988
989 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
990 {
991 unsigned long size, order;
992
993 if (!q)
994 return;
995
996 size = num_entries * LDC_PACKET_SIZE;
997 order = get_order(size);
998
999 free_pages((unsigned long)q, order);
1000 }
1001
1002 /* XXX Make this configurable... XXX */
1003 #define LDC_IOTABLE_SIZE (8 * 1024)
1004
1005 static int ldc_iommu_init(struct ldc_channel *lp)
1006 {
1007 unsigned long sz, num_tsb_entries, tsbsize, order;
1008 struct ldc_iommu *iommu = &lp->iommu;
1009 struct ldc_mtable_entry *table;
1010 unsigned long hv_err;
1011 int err;
1012
1013 num_tsb_entries = LDC_IOTABLE_SIZE;
1014 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1015
1016 spin_lock_init(&iommu->lock);
1017
1018 sz = num_tsb_entries / 8;
1019 sz = (sz + 7UL) & ~7UL;
1020 iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1021 if (!iommu->arena.map) {
1022 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1023 return -ENOMEM;
1024 }
1025
1026 iommu->arena.limit = num_tsb_entries;
1027
1028 order = get_order(tsbsize);
1029
1030 table = (struct ldc_mtable_entry *)
1031 __get_free_pages(GFP_KERNEL, order);
1032 err = -ENOMEM;
1033 if (!table) {
1034 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1035 "size=%lu order=%lu\n", tsbsize, order);
1036 goto out_free_map;
1037 }
1038
1039 memset(table, 0, PAGE_SIZE << order);
1040
1041 iommu->page_table = table;
1042
1043 hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1044 num_tsb_entries);
1045 err = -EINVAL;
1046 if (hv_err)
1047 goto out_free_table;
1048
1049 return 0;
1050
1051 out_free_table:
1052 free_pages((unsigned long) table, order);
1053 iommu->page_table = NULL;
1054
1055 out_free_map:
1056 kfree(iommu->arena.map);
1057 iommu->arena.map = NULL;
1058
1059 return err;
1060 }
1061
1062 static void ldc_iommu_release(struct ldc_channel *lp)
1063 {
1064 struct ldc_iommu *iommu = &lp->iommu;
1065 unsigned long num_tsb_entries, tsbsize, order;
1066
1067 (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1068
1069 num_tsb_entries = iommu->arena.limit;
1070 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1071 order = get_order(tsbsize);
1072
1073 free_pages((unsigned long) iommu->page_table, order);
1074 iommu->page_table = NULL;
1075
1076 kfree(iommu->arena.map);
1077 iommu->arena.map = NULL;
1078 }
1079
1080 struct ldc_channel *ldc_alloc(unsigned long id,
1081 const struct ldc_channel_config *cfgp,
1082 void *event_arg)
1083 {
1084 struct ldc_channel *lp;
1085 const struct ldc_mode_ops *mops;
1086 unsigned long dummy1, dummy2, hv_err;
1087 u8 mss, *mssbuf;
1088 int err;
1089
1090 err = -ENODEV;
1091 if (!ldom_domaining_enabled)
1092 goto out_err;
1093
1094 err = -EINVAL;
1095 if (!cfgp)
1096 goto out_err;
1097
1098 switch (cfgp->mode) {
1099 case LDC_MODE_RAW:
1100 mops = &raw_ops;
1101 mss = LDC_PACKET_SIZE;
1102 break;
1103
1104 case LDC_MODE_UNRELIABLE:
1105 mops = &nonraw_ops;
1106 mss = LDC_PACKET_SIZE - 8;
1107 break;
1108
1109 case LDC_MODE_STREAM:
1110 mops = &stream_ops;
1111 mss = LDC_PACKET_SIZE - 8 - 8;
1112 break;
1113
1114 default:
1115 goto out_err;
1116 }
1117
1118 if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1119 goto out_err;
1120
1121 hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1122 err = -ENODEV;
1123 if (hv_err == HV_ECHANNEL)
1124 goto out_err;
1125
1126 err = -EEXIST;
1127 if (__ldc_channel_exists(id))
1128 goto out_err;
1129
1130 mssbuf = NULL;
1131
1132 lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1133 err = -ENOMEM;
1134 if (!lp)
1135 goto out_err;
1136
1137 spin_lock_init(&lp->lock);
1138
1139 lp->id = id;
1140
1141 err = ldc_iommu_init(lp);
1142 if (err)
1143 goto out_free_ldc;
1144
1145 lp->mops = mops;
1146 lp->mss = mss;
1147
1148 lp->cfg = *cfgp;
1149 if (!lp->cfg.mtu)
1150 lp->cfg.mtu = LDC_DEFAULT_MTU;
1151
1152 if (lp->cfg.mode == LDC_MODE_STREAM) {
1153 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1154 if (!mssbuf) {
1155 err = -ENOMEM;
1156 goto out_free_iommu;
1157 }
1158 lp->mssbuf = mssbuf;
1159 }
1160
1161 lp->event_arg = event_arg;
1162
1163 /* XXX allow setting via ldc_channel_config to override defaults
1164 * XXX or use some formula based upon mtu
1165 */
1166 lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1167 lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1168
1169 err = alloc_queue("TX", lp->tx_num_entries,
1170 &lp->tx_base, &lp->tx_ra);
1171 if (err)
1172 goto out_free_mssbuf;
1173
1174 err = alloc_queue("RX", lp->rx_num_entries,
1175 &lp->rx_base, &lp->rx_ra);
1176 if (err)
1177 goto out_free_txq;
1178
1179 lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1180
1181 lp->hs_state = LDC_HS_CLOSED;
1182 ldc_set_state(lp, LDC_STATE_INIT);
1183
1184 INIT_HLIST_NODE(&lp->list);
1185 hlist_add_head(&lp->list, &ldc_channel_list);
1186
1187 INIT_HLIST_HEAD(&lp->mh_list);
1188
1189 return lp;
1190
1191 out_free_txq:
1192 free_queue(lp->tx_num_entries, lp->tx_base);
1193
1194 out_free_mssbuf:
1195 kfree(mssbuf);
1196
1197 out_free_iommu:
1198 ldc_iommu_release(lp);
1199
1200 out_free_ldc:
1201 kfree(lp);
1202
1203 out_err:
1204 return ERR_PTR(err);
1205 }
1206 EXPORT_SYMBOL(ldc_alloc);
1207
1208 void ldc_free(struct ldc_channel *lp)
1209 {
1210 if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1211 free_irq(lp->cfg.rx_irq, lp);
1212 free_irq(lp->cfg.tx_irq, lp);
1213 }
1214
1215 if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1216 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1217 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1218 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1219 }
1220 if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1221 free_queue(lp->tx_num_entries, lp->tx_base);
1222 free_queue(lp->rx_num_entries, lp->rx_base);
1223 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1224 }
1225
1226 hlist_del(&lp->list);
1227
1228 kfree(lp->mssbuf);
1229
1230 ldc_iommu_release(lp);
1231
1232 kfree(lp);
1233 }
1234 EXPORT_SYMBOL(ldc_free);
1235
1236 /* Bind the channel. This registers the LDC queues with
1237 * the hypervisor and puts the channel into a pseudo-listening
1238 * state. This does not initiate a handshake, ldc_connect() does
1239 * that.
1240 */
1241 int ldc_bind(struct ldc_channel *lp, const char *name)
1242 {
1243 unsigned long hv_err, flags;
1244 int err = -EINVAL;
1245
1246 if (!name ||
1247 (lp->state != LDC_STATE_INIT))
1248 return -EINVAL;
1249
1250 snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1251 snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1252
1253 err = request_irq(lp->cfg.rx_irq, ldc_rx,
1254 IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1255 lp->rx_irq_name, lp);
1256 if (err)
1257 return err;
1258
1259 err = request_irq(lp->cfg.tx_irq, ldc_tx,
1260 IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1261 lp->tx_irq_name, lp);
1262 if (err) {
1263 free_irq(lp->cfg.rx_irq, lp);
1264 return err;
1265 }
1266
1267
1268 spin_lock_irqsave(&lp->lock, flags);
1269
1270 enable_irq(lp->cfg.rx_irq);
1271 enable_irq(lp->cfg.tx_irq);
1272
1273 lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1274
1275 err = -ENODEV;
1276 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1277 if (hv_err)
1278 goto out_free_irqs;
1279
1280 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1281 if (hv_err)
1282 goto out_free_irqs;
1283
1284 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1285 if (hv_err)
1286 goto out_unmap_tx;
1287
1288 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1289 if (hv_err)
1290 goto out_unmap_tx;
1291
1292 lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1293
1294 hv_err = sun4v_ldc_tx_get_state(lp->id,
1295 &lp->tx_head,
1296 &lp->tx_tail,
1297 &lp->chan_state);
1298 err = -EBUSY;
1299 if (hv_err)
1300 goto out_unmap_rx;
1301
1302 lp->tx_acked = lp->tx_head;
1303
1304 lp->hs_state = LDC_HS_OPEN;
1305 ldc_set_state(lp, LDC_STATE_BOUND);
1306
1307 spin_unlock_irqrestore(&lp->lock, flags);
1308
1309 return 0;
1310
1311 out_unmap_rx:
1312 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1313 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1314
1315 out_unmap_tx:
1316 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1317
1318 out_free_irqs:
1319 lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1320 free_irq(lp->cfg.tx_irq, lp);
1321 free_irq(lp->cfg.rx_irq, lp);
1322
1323 spin_unlock_irqrestore(&lp->lock, flags);
1324
1325 return err;
1326 }
1327 EXPORT_SYMBOL(ldc_bind);
1328
1329 int ldc_connect(struct ldc_channel *lp)
1330 {
1331 unsigned long flags;
1332 int err;
1333
1334 if (lp->cfg.mode == LDC_MODE_RAW)
1335 return -EINVAL;
1336
1337 spin_lock_irqsave(&lp->lock, flags);
1338
1339 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1340 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1341 lp->hs_state != LDC_HS_OPEN)
1342 err = -EINVAL;
1343 else
1344 err = start_handshake(lp);
1345
1346 spin_unlock_irqrestore(&lp->lock, flags);
1347
1348 return err;
1349 }
1350 EXPORT_SYMBOL(ldc_connect);
1351
1352 int ldc_disconnect(struct ldc_channel *lp)
1353 {
1354 unsigned long hv_err, flags;
1355 int err;
1356
1357 if (lp->cfg.mode == LDC_MODE_RAW)
1358 return -EINVAL;
1359
1360 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1361 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1362 return -EINVAL;
1363
1364 spin_lock_irqsave(&lp->lock, flags);
1365
1366 err = -ENODEV;
1367 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1368 if (hv_err)
1369 goto out_err;
1370
1371 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1372 if (hv_err)
1373 goto out_err;
1374
1375 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1376 if (hv_err)
1377 goto out_err;
1378
1379 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1380 if (hv_err)
1381 goto out_err;
1382
1383 ldc_set_state(lp, LDC_STATE_BOUND);
1384 lp->hs_state = LDC_HS_OPEN;
1385 lp->flags |= LDC_FLAG_RESET;
1386
1387 spin_unlock_irqrestore(&lp->lock, flags);
1388
1389 return 0;
1390
1391 out_err:
1392 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1393 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1394 free_irq(lp->cfg.tx_irq, lp);
1395 free_irq(lp->cfg.rx_irq, lp);
1396 lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1397 LDC_FLAG_REGISTERED_QUEUES);
1398 ldc_set_state(lp, LDC_STATE_INIT);
1399
1400 spin_unlock_irqrestore(&lp->lock, flags);
1401
1402 return err;
1403 }
1404 EXPORT_SYMBOL(ldc_disconnect);
1405
1406 int ldc_state(struct ldc_channel *lp)
1407 {
1408 return lp->state;
1409 }
1410 EXPORT_SYMBOL(ldc_state);
1411
1412 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1413 {
1414 struct ldc_packet *p;
1415 unsigned long new_tail;
1416 int err;
1417
1418 if (size > LDC_PACKET_SIZE)
1419 return -EMSGSIZE;
1420
1421 p = data_get_tx_packet(lp, &new_tail);
1422 if (!p)
1423 return -EAGAIN;
1424
1425 memcpy(p, buf, size);
1426
1427 err = send_tx_packet(lp, p, new_tail);
1428 if (!err)
1429 err = size;
1430
1431 return err;
1432 }
1433
1434 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1435 {
1436 struct ldc_packet *p;
1437 unsigned long hv_err, new;
1438 int err;
1439
1440 if (size < LDC_PACKET_SIZE)
1441 return -EINVAL;
1442
1443 hv_err = sun4v_ldc_rx_get_state(lp->id,
1444 &lp->rx_head,
1445 &lp->rx_tail,
1446 &lp->chan_state);
1447 if (hv_err)
1448 return ldc_abort(lp);
1449
1450 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1451 lp->chan_state == LDC_CHANNEL_RESETTING)
1452 return -ECONNRESET;
1453
1454 if (lp->rx_head == lp->rx_tail)
1455 return 0;
1456
1457 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1458 memcpy(buf, p, LDC_PACKET_SIZE);
1459
1460 new = rx_advance(lp, lp->rx_head);
1461 lp->rx_head = new;
1462
1463 err = __set_rx_head(lp, new);
1464 if (err < 0)
1465 err = -ECONNRESET;
1466 else
1467 err = LDC_PACKET_SIZE;
1468
1469 return err;
1470 }
1471
1472 static const struct ldc_mode_ops raw_ops = {
1473 .write = write_raw,
1474 .read = read_raw,
1475 };
1476
1477 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1478 unsigned int size)
1479 {
1480 unsigned long hv_err, tail;
1481 unsigned int copied;
1482 u32 seq;
1483 int err;
1484
1485 hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1486 &lp->chan_state);
1487 if (unlikely(hv_err))
1488 return -EBUSY;
1489
1490 if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1491 return ldc_abort(lp);
1492
1493 if (!tx_has_space_for(lp, size))
1494 return -EAGAIN;
1495
1496 seq = lp->snd_nxt;
1497 copied = 0;
1498 tail = lp->tx_tail;
1499 while (copied < size) {
1500 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1501 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1502 p->u.u_data :
1503 p->u.r.r_data);
1504 int data_len;
1505
1506 p->type = LDC_DATA;
1507 p->stype = LDC_INFO;
1508 p->ctrl = 0;
1509
1510 data_len = size - copied;
1511 if (data_len > lp->mss)
1512 data_len = lp->mss;
1513
1514 BUG_ON(data_len > LDC_LEN);
1515
1516 p->env = (data_len |
1517 (copied == 0 ? LDC_START : 0) |
1518 (data_len == size - copied ? LDC_STOP : 0));
1519
1520 p->seqid = ++seq;
1521
1522 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1523 p->type,
1524 p->stype,
1525 p->ctrl,
1526 p->env,
1527 p->seqid);
1528
1529 memcpy(data, buf, data_len);
1530 buf += data_len;
1531 copied += data_len;
1532
1533 tail = tx_advance(lp, tail);
1534 }
1535
1536 err = set_tx_tail(lp, tail);
1537 if (!err) {
1538 lp->snd_nxt = seq;
1539 err = size;
1540 }
1541
1542 return err;
1543 }
1544
1545 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1546 struct ldc_packet *first_frag)
1547 {
1548 int err;
1549
1550 if (first_frag)
1551 lp->rcv_nxt = first_frag->seqid - 1;
1552
1553 err = send_data_nack(lp, p);
1554 if (err)
1555 return err;
1556
1557 err = __set_rx_head(lp, lp->rx_tail);
1558 if (err < 0)
1559 return ldc_abort(lp);
1560
1561 return 0;
1562 }
1563
1564 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1565 {
1566 if (p->stype & LDC_ACK) {
1567 int err = process_data_ack(lp, p);
1568 if (err)
1569 return err;
1570 }
1571 if (p->stype & LDC_NACK)
1572 return ldc_abort(lp);
1573
1574 return 0;
1575 }
1576
1577 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1578 {
1579 unsigned long dummy;
1580 int limit = 1000;
1581
1582 ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1583 cur_head, lp->rx_head, lp->rx_tail);
1584 while (limit-- > 0) {
1585 unsigned long hv_err;
1586
1587 hv_err = sun4v_ldc_rx_get_state(lp->id,
1588 &dummy,
1589 &lp->rx_tail,
1590 &lp->chan_state);
1591 if (hv_err)
1592 return ldc_abort(lp);
1593
1594 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1595 lp->chan_state == LDC_CHANNEL_RESETTING)
1596 return -ECONNRESET;
1597
1598 if (cur_head != lp->rx_tail) {
1599 ldcdbg(DATA, "DATA WAIT DONE "
1600 "head[%lx] tail[%lx] chan_state[%lx]\n",
1601 dummy, lp->rx_tail, lp->chan_state);
1602 return 0;
1603 }
1604
1605 udelay(1);
1606 }
1607 return -EAGAIN;
1608 }
1609
1610 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1611 {
1612 int err = __set_rx_head(lp, head);
1613
1614 if (err < 0)
1615 return ldc_abort(lp);
1616
1617 lp->rx_head = head;
1618 return 0;
1619 }
1620
1621 static void send_data_ack(struct ldc_channel *lp)
1622 {
1623 unsigned long new_tail;
1624 struct ldc_packet *p;
1625
1626 p = data_get_tx_packet(lp, &new_tail);
1627 if (likely(p)) {
1628 int err;
1629
1630 memset(p, 0, sizeof(*p));
1631 p->type = LDC_DATA;
1632 p->stype = LDC_ACK;
1633 p->ctrl = 0;
1634 p->seqid = lp->snd_nxt + 1;
1635 p->u.r.ackid = lp->rcv_nxt;
1636
1637 err = send_tx_packet(lp, p, new_tail);
1638 if (!err)
1639 lp->snd_nxt++;
1640 }
1641 }
1642
1643 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1644 {
1645 struct ldc_packet *first_frag;
1646 unsigned long hv_err, new;
1647 int err, copied;
1648
1649 hv_err = sun4v_ldc_rx_get_state(lp->id,
1650 &lp->rx_head,
1651 &lp->rx_tail,
1652 &lp->chan_state);
1653 if (hv_err)
1654 return ldc_abort(lp);
1655
1656 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1657 lp->chan_state == LDC_CHANNEL_RESETTING)
1658 return -ECONNRESET;
1659
1660 if (lp->rx_head == lp->rx_tail)
1661 return 0;
1662
1663 first_frag = NULL;
1664 copied = err = 0;
1665 new = lp->rx_head;
1666 while (1) {
1667 struct ldc_packet *p;
1668 int pkt_len;
1669
1670 BUG_ON(new == lp->rx_tail);
1671 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1672
1673 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1674 "rcv_nxt[%08x]\n",
1675 p->type,
1676 p->stype,
1677 p->ctrl,
1678 p->env,
1679 p->seqid,
1680 p->u.r.ackid,
1681 lp->rcv_nxt);
1682
1683 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1684 err = rx_bad_seq(lp, p, first_frag);
1685 copied = 0;
1686 break;
1687 }
1688
1689 if (p->type & LDC_CTRL) {
1690 err = process_control_frame(lp, p);
1691 if (err < 0)
1692 break;
1693 err = 0;
1694 }
1695
1696 lp->rcv_nxt = p->seqid;
1697
1698 if (!(p->type & LDC_DATA)) {
1699 new = rx_advance(lp, new);
1700 goto no_data;
1701 }
1702 if (p->stype & (LDC_ACK | LDC_NACK)) {
1703 err = data_ack_nack(lp, p);
1704 if (err)
1705 break;
1706 }
1707 if (!(p->stype & LDC_INFO)) {
1708 new = rx_advance(lp, new);
1709 err = rx_set_head(lp, new);
1710 if (err)
1711 break;
1712 goto no_data;
1713 }
1714
1715 pkt_len = p->env & LDC_LEN;
1716
1717 /* Every initial packet starts with the START bit set.
1718 *
1719 * Singleton packets will have both START+STOP set.
1720 *
1721 * Fragments will have START set in the first frame, STOP
1722 * set in the last frame, and neither bit set in middle
1723 * frames of the packet.
1724 *
1725 * Therefore if we are at the beginning of a packet and
1726 * we don't see START, or we are in the middle of a fragmented
1727 * packet and do see START, we are unsynchronized and should
1728 * flush the RX queue.
1729 */
1730 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1731 (first_frag != NULL && (p->env & LDC_START))) {
1732 if (!first_frag)
1733 new = rx_advance(lp, new);
1734
1735 err = rx_set_head(lp, new);
1736 if (err)
1737 break;
1738
1739 if (!first_frag)
1740 goto no_data;
1741 }
1742 if (!first_frag)
1743 first_frag = p;
1744
1745 if (pkt_len > size - copied) {
1746 /* User didn't give us a big enough buffer,
1747 * what to do? This is a pretty serious error.
1748 *
1749 * Since we haven't updated the RX ring head to
1750 * consume any of the packets, signal the error
1751 * to the user and just leave the RX ring alone.
1752 *
1753 * This seems the best behavior because this allows
1754 * a user of the LDC layer to start with a small
1755 * RX buffer for ldc_read() calls and use -EMSGSIZE
1756 * as a cue to enlarge it's read buffer.
1757 */
1758 err = -EMSGSIZE;
1759 break;
1760 }
1761
1762 /* Ok, we are gonna eat this one. */
1763 new = rx_advance(lp, new);
1764
1765 memcpy(buf,
1766 (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1767 p->u.u_data : p->u.r.r_data), pkt_len);
1768 buf += pkt_len;
1769 copied += pkt_len;
1770
1771 if (p->env & LDC_STOP)
1772 break;
1773
1774 no_data:
1775 if (new == lp->rx_tail) {
1776 err = rx_data_wait(lp, new);
1777 if (err)
1778 break;
1779 }
1780 }
1781
1782 if (!err)
1783 err = rx_set_head(lp, new);
1784
1785 if (err && first_frag)
1786 lp->rcv_nxt = first_frag->seqid - 1;
1787
1788 if (!err) {
1789 err = copied;
1790 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1791 send_data_ack(lp);
1792 }
1793
1794 return err;
1795 }
1796
1797 static const struct ldc_mode_ops nonraw_ops = {
1798 .write = write_nonraw,
1799 .read = read_nonraw,
1800 };
1801
1802 static int write_stream(struct ldc_channel *lp, const void *buf,
1803 unsigned int size)
1804 {
1805 if (size > lp->cfg.mtu)
1806 size = lp->cfg.mtu;
1807 return write_nonraw(lp, buf, size);
1808 }
1809
1810 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1811 {
1812 if (!lp->mssbuf_len) {
1813 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1814 if (err < 0)
1815 return err;
1816
1817 lp->mssbuf_len = err;
1818 lp->mssbuf_off = 0;
1819 }
1820
1821 if (size > lp->mssbuf_len)
1822 size = lp->mssbuf_len;
1823 memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1824
1825 lp->mssbuf_off += size;
1826 lp->mssbuf_len -= size;
1827
1828 return size;
1829 }
1830
1831 static const struct ldc_mode_ops stream_ops = {
1832 .write = write_stream,
1833 .read = read_stream,
1834 };
1835
1836 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1837 {
1838 unsigned long flags;
1839 int err;
1840
1841 if (!buf)
1842 return -EINVAL;
1843
1844 if (!size)
1845 return 0;
1846
1847 spin_lock_irqsave(&lp->lock, flags);
1848
1849 if (lp->hs_state != LDC_HS_COMPLETE)
1850 err = -ENOTCONN;
1851 else
1852 err = lp->mops->write(lp, buf, size);
1853
1854 spin_unlock_irqrestore(&lp->lock, flags);
1855
1856 return err;
1857 }
1858 EXPORT_SYMBOL(ldc_write);
1859
1860 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1861 {
1862 unsigned long flags;
1863 int err;
1864
1865 if (!buf)
1866 return -EINVAL;
1867
1868 if (!size)
1869 return 0;
1870
1871 spin_lock_irqsave(&lp->lock, flags);
1872
1873 if (lp->hs_state != LDC_HS_COMPLETE)
1874 err = -ENOTCONN;
1875 else
1876 err = lp->mops->read(lp, buf, size);
1877
1878 spin_unlock_irqrestore(&lp->lock, flags);
1879
1880 return err;
1881 }
1882 EXPORT_SYMBOL(ldc_read);
1883
1884 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1885 {
1886 struct iommu_arena *arena = &iommu->arena;
1887 unsigned long n, start, end, limit;
1888 int pass;
1889
1890 limit = arena->limit;
1891 start = arena->hint;
1892 pass = 0;
1893
1894 again:
1895 n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1896 end = n + npages;
1897 if (unlikely(end >= limit)) {
1898 if (likely(pass < 1)) {
1899 limit = start;
1900 start = 0;
1901 pass++;
1902 goto again;
1903 } else {
1904 /* Scanned the whole thing, give up. */
1905 return -1;
1906 }
1907 }
1908 bitmap_set(arena->map, n, npages);
1909
1910 arena->hint = end;
1911
1912 return n;
1913 }
1914
1915 #define COOKIE_PGSZ_CODE 0xf000000000000000ULL
1916 #define COOKIE_PGSZ_CODE_SHIFT 60ULL
1917
1918 static u64 pagesize_code(void)
1919 {
1920 switch (PAGE_SIZE) {
1921 default:
1922 case (8ULL * 1024ULL):
1923 return 0;
1924 case (64ULL * 1024ULL):
1925 return 1;
1926 case (512ULL * 1024ULL):
1927 return 2;
1928 case (4ULL * 1024ULL * 1024ULL):
1929 return 3;
1930 case (32ULL * 1024ULL * 1024ULL):
1931 return 4;
1932 case (256ULL * 1024ULL * 1024ULL):
1933 return 5;
1934 }
1935 }
1936
1937 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1938 {
1939 return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1940 (index << PAGE_SHIFT) |
1941 page_offset);
1942 }
1943
1944 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1945 {
1946 u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1947
1948 cookie &= ~COOKIE_PGSZ_CODE;
1949
1950 *shift = szcode * 3;
1951
1952 return (cookie >> (13ULL + (szcode * 3ULL)));
1953 }
1954
1955 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1956 unsigned long npages)
1957 {
1958 long entry;
1959
1960 entry = arena_alloc(iommu, npages);
1961 if (unlikely(entry < 0))
1962 return NULL;
1963
1964 return iommu->page_table + entry;
1965 }
1966
1967 static u64 perm_to_mte(unsigned int map_perm)
1968 {
1969 u64 mte_base;
1970
1971 mte_base = pagesize_code();
1972
1973 if (map_perm & LDC_MAP_SHADOW) {
1974 if (map_perm & LDC_MAP_R)
1975 mte_base |= LDC_MTE_COPY_R;
1976 if (map_perm & LDC_MAP_W)
1977 mte_base |= LDC_MTE_COPY_W;
1978 }
1979 if (map_perm & LDC_MAP_DIRECT) {
1980 if (map_perm & LDC_MAP_R)
1981 mte_base |= LDC_MTE_READ;
1982 if (map_perm & LDC_MAP_W)
1983 mte_base |= LDC_MTE_WRITE;
1984 if (map_perm & LDC_MAP_X)
1985 mte_base |= LDC_MTE_EXEC;
1986 }
1987 if (map_perm & LDC_MAP_IO) {
1988 if (map_perm & LDC_MAP_R)
1989 mte_base |= LDC_MTE_IOMMU_R;
1990 if (map_perm & LDC_MAP_W)
1991 mte_base |= LDC_MTE_IOMMU_W;
1992 }
1993
1994 return mte_base;
1995 }
1996
1997 static int pages_in_region(unsigned long base, long len)
1998 {
1999 int count = 0;
2000
2001 do {
2002 unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2003
2004 len -= (new - base);
2005 base = new;
2006 count++;
2007 } while (len > 0);
2008
2009 return count;
2010 }
2011
2012 struct cookie_state {
2013 struct ldc_mtable_entry *page_table;
2014 struct ldc_trans_cookie *cookies;
2015 u64 mte_base;
2016 u64 prev_cookie;
2017 u32 pte_idx;
2018 u32 nc;
2019 };
2020
2021 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2022 unsigned long off, unsigned long len)
2023 {
2024 do {
2025 unsigned long tlen, new = pa + PAGE_SIZE;
2026 u64 this_cookie;
2027
2028 sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2029
2030 tlen = PAGE_SIZE;
2031 if (off)
2032 tlen = PAGE_SIZE - off;
2033 if (tlen > len)
2034 tlen = len;
2035
2036 this_cookie = make_cookie(sp->pte_idx,
2037 pagesize_code(), off);
2038
2039 off = 0;
2040
2041 if (this_cookie == sp->prev_cookie) {
2042 sp->cookies[sp->nc - 1].cookie_size += tlen;
2043 } else {
2044 sp->cookies[sp->nc].cookie_addr = this_cookie;
2045 sp->cookies[sp->nc].cookie_size = tlen;
2046 sp->nc++;
2047 }
2048 sp->prev_cookie = this_cookie + tlen;
2049
2050 sp->pte_idx++;
2051
2052 len -= tlen;
2053 pa = new;
2054 } while (len > 0);
2055 }
2056
2057 static int sg_count_one(struct scatterlist *sg)
2058 {
2059 unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2060 long len = sg->length;
2061
2062 if ((sg->offset | len) & (8UL - 1))
2063 return -EFAULT;
2064
2065 return pages_in_region(base + sg->offset, len);
2066 }
2067
2068 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2069 {
2070 int count;
2071 int i;
2072
2073 count = 0;
2074 for (i = 0; i < num_sg; i++) {
2075 int err = sg_count_one(sg + i);
2076 if (err < 0)
2077 return err;
2078 count += err;
2079 }
2080
2081 return count;
2082 }
2083
2084 int ldc_map_sg(struct ldc_channel *lp,
2085 struct scatterlist *sg, int num_sg,
2086 struct ldc_trans_cookie *cookies, int ncookies,
2087 unsigned int map_perm)
2088 {
2089 unsigned long i, npages, flags;
2090 struct ldc_mtable_entry *base;
2091 struct cookie_state state;
2092 struct ldc_iommu *iommu;
2093 int err;
2094
2095 if (map_perm & ~LDC_MAP_ALL)
2096 return -EINVAL;
2097
2098 err = sg_count_pages(sg, num_sg);
2099 if (err < 0)
2100 return err;
2101
2102 npages = err;
2103 if (err > ncookies)
2104 return -EMSGSIZE;
2105
2106 iommu = &lp->iommu;
2107
2108 spin_lock_irqsave(&iommu->lock, flags);
2109 base = alloc_npages(iommu, npages);
2110 spin_unlock_irqrestore(&iommu->lock, flags);
2111
2112 if (!base)
2113 return -ENOMEM;
2114
2115 state.page_table = iommu->page_table;
2116 state.cookies = cookies;
2117 state.mte_base = perm_to_mte(map_perm);
2118 state.prev_cookie = ~(u64)0;
2119 state.pte_idx = (base - iommu->page_table);
2120 state.nc = 0;
2121
2122 for (i = 0; i < num_sg; i++)
2123 fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2124 sg[i].offset, sg[i].length);
2125
2126 return state.nc;
2127 }
2128 EXPORT_SYMBOL(ldc_map_sg);
2129
2130 int ldc_map_single(struct ldc_channel *lp,
2131 void *buf, unsigned int len,
2132 struct ldc_trans_cookie *cookies, int ncookies,
2133 unsigned int map_perm)
2134 {
2135 unsigned long npages, pa, flags;
2136 struct ldc_mtable_entry *base;
2137 struct cookie_state state;
2138 struct ldc_iommu *iommu;
2139
2140 if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2141 return -EINVAL;
2142
2143 pa = __pa(buf);
2144 if ((pa | len) & (8UL - 1))
2145 return -EFAULT;
2146
2147 npages = pages_in_region(pa, len);
2148
2149 iommu = &lp->iommu;
2150
2151 spin_lock_irqsave(&iommu->lock, flags);
2152 base = alloc_npages(iommu, npages);
2153 spin_unlock_irqrestore(&iommu->lock, flags);
2154
2155 if (!base)
2156 return -ENOMEM;
2157
2158 state.page_table = iommu->page_table;
2159 state.cookies = cookies;
2160 state.mte_base = perm_to_mte(map_perm);
2161 state.prev_cookie = ~(u64)0;
2162 state.pte_idx = (base - iommu->page_table);
2163 state.nc = 0;
2164 fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2165 BUG_ON(state.nc != 1);
2166
2167 return state.nc;
2168 }
2169 EXPORT_SYMBOL(ldc_map_single);
2170
2171 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2172 u64 cookie, u64 size)
2173 {
2174 struct iommu_arena *arena = &iommu->arena;
2175 unsigned long i, shift, index, npages;
2176 struct ldc_mtable_entry *base;
2177
2178 npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2179 index = cookie_to_index(cookie, &shift);
2180 base = iommu->page_table + index;
2181
2182 BUG_ON(index > arena->limit ||
2183 (index + npages) > arena->limit);
2184
2185 for (i = 0; i < npages; i++) {
2186 if (base->cookie)
2187 sun4v_ldc_revoke(id, cookie + (i << shift),
2188 base->cookie);
2189 base->mte = 0;
2190 __clear_bit(index + i, arena->map);
2191 }
2192 }
2193
2194 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2195 int ncookies)
2196 {
2197 struct ldc_iommu *iommu = &lp->iommu;
2198 unsigned long flags;
2199 int i;
2200
2201 spin_lock_irqsave(&iommu->lock, flags);
2202 for (i = 0; i < ncookies; i++) {
2203 u64 addr = cookies[i].cookie_addr;
2204 u64 size = cookies[i].cookie_size;
2205
2206 free_npages(lp->id, iommu, addr, size);
2207 }
2208 spin_unlock_irqrestore(&iommu->lock, flags);
2209 }
2210 EXPORT_SYMBOL(ldc_unmap);
2211
2212 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2213 void *buf, unsigned int len, unsigned long offset,
2214 struct ldc_trans_cookie *cookies, int ncookies)
2215 {
2216 unsigned int orig_len;
2217 unsigned long ra;
2218 int i;
2219
2220 if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2221 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2222 lp->id, copy_dir);
2223 return -EINVAL;
2224 }
2225
2226 ra = __pa(buf);
2227 if ((ra | len | offset) & (8UL - 1)) {
2228 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2229 "ra[%lx] len[%x] offset[%lx]\n",
2230 lp->id, ra, len, offset);
2231 return -EFAULT;
2232 }
2233
2234 if (lp->hs_state != LDC_HS_COMPLETE ||
2235 (lp->flags & LDC_FLAG_RESET)) {
2236 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2237 "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2238 return -ECONNRESET;
2239 }
2240
2241 orig_len = len;
2242 for (i = 0; i < ncookies; i++) {
2243 unsigned long cookie_raddr = cookies[i].cookie_addr;
2244 unsigned long this_len = cookies[i].cookie_size;
2245 unsigned long actual_len;
2246
2247 if (unlikely(offset)) {
2248 unsigned long this_off = offset;
2249
2250 if (this_off > this_len)
2251 this_off = this_len;
2252
2253 offset -= this_off;
2254 this_len -= this_off;
2255 if (!this_len)
2256 continue;
2257 cookie_raddr += this_off;
2258 }
2259
2260 if (this_len > len)
2261 this_len = len;
2262
2263 while (1) {
2264 unsigned long hv_err;
2265
2266 hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2267 cookie_raddr, ra,
2268 this_len, &actual_len);
2269 if (unlikely(hv_err)) {
2270 printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2271 "HV error %lu\n",
2272 lp->id, hv_err);
2273 if (lp->hs_state != LDC_HS_COMPLETE ||
2274 (lp->flags & LDC_FLAG_RESET))
2275 return -ECONNRESET;
2276 else
2277 return -EFAULT;
2278 }
2279
2280 cookie_raddr += actual_len;
2281 ra += actual_len;
2282 len -= actual_len;
2283 if (actual_len == this_len)
2284 break;
2285
2286 this_len -= actual_len;
2287 }
2288
2289 if (!len)
2290 break;
2291 }
2292
2293 /* It is caller policy what to do about short copies.
2294 * For example, a networking driver can declare the
2295 * packet a runt and drop it.
2296 */
2297
2298 return orig_len - len;
2299 }
2300 EXPORT_SYMBOL(ldc_copy);
2301
2302 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2303 struct ldc_trans_cookie *cookies, int *ncookies,
2304 unsigned int map_perm)
2305 {
2306 void *buf;
2307 int err;
2308
2309 if (len & (8UL - 1))
2310 return ERR_PTR(-EINVAL);
2311
2312 buf = kzalloc(len, GFP_KERNEL);
2313 if (!buf)
2314 return ERR_PTR(-ENOMEM);
2315
2316 err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2317 if (err < 0) {
2318 kfree(buf);
2319 return ERR_PTR(err);
2320 }
2321 *ncookies = err;
2322
2323 return buf;
2324 }
2325 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2326
2327 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2328 struct ldc_trans_cookie *cookies, int ncookies)
2329 {
2330 ldc_unmap(lp, cookies, ncookies);
2331 kfree(buf);
2332 }
2333 EXPORT_SYMBOL(ldc_free_exp_dring);
2334
2335 static int __init ldc_init(void)
2336 {
2337 unsigned long major, minor;
2338 struct mdesc_handle *hp;
2339 const u64 *v;
2340 int err;
2341 u64 mp;
2342
2343 hp = mdesc_grab();
2344 if (!hp)
2345 return -ENODEV;
2346
2347 mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2348 err = -ENODEV;
2349 if (mp == MDESC_NODE_NULL)
2350 goto out;
2351
2352 v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2353 if (!v)
2354 goto out;
2355
2356 major = 1;
2357 minor = 0;
2358 if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2359 printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2360 goto out;
2361 }
2362
2363 printk(KERN_INFO "%s", version);
2364
2365 if (!*v) {
2366 printk(KERN_INFO PFX "Domaining disabled.\n");
2367 goto out;
2368 }
2369 ldom_domaining_enabled = 1;
2370 err = 0;
2371
2372 out:
2373 mdesc_release(hp);
2374 return err;
2375 }
2376
2377 core_initcall(ldc_init);
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