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Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[linux/fpc-iii.git] / arch / sparc / kernel / ldc.c
blobdf39a0f0d27af2c250a3c7da9a2b50208d240e5f
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, hv_err, flags;
794 unsigned int event_mask;
795
796 spin_lock_irqsave(&lp->lock, flags);
797
798 orig_state = lp->chan_state;
799 hv_err = sun4v_ldc_rx_get_state(lp->id,
800 &lp->rx_head,
801 &lp->rx_tail,
802 &lp->chan_state);
803
804 ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
805 orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
806
807 event_mask = 0;
808
809 if (lp->cfg.mode == LDC_MODE_RAW &&
810 lp->chan_state == LDC_CHANNEL_UP) {
811 lp->hs_state = LDC_HS_COMPLETE;
812 ldc_set_state(lp, LDC_STATE_CONNECTED);
813
814 event_mask |= LDC_EVENT_UP;
815
816 orig_state = lp->chan_state;
817 }
818
819 /* If we are in reset state, flush the RX queue and ignore
820 * everything.
821 */
822 if (lp->flags & LDC_FLAG_RESET) {
823 (void) __set_rx_head(lp, lp->rx_tail);
824 goto out;
825 }
826
827 /* Once we finish the handshake, we let the ldc_read()
828 * paths do all of the control frame and state management.
829 * Just trigger the callback.
830 */
831 if (lp->hs_state == LDC_HS_COMPLETE) {
832 handshake_complete:
833 if (lp->chan_state != orig_state) {
834 unsigned int event = LDC_EVENT_RESET;
835
836 if (lp->chan_state == LDC_CHANNEL_UP)
837 event = LDC_EVENT_UP;
838
839 event_mask |= event;
840 }
841 if (lp->rx_head != lp->rx_tail)
842 event_mask |= LDC_EVENT_DATA_READY;
843
844 goto out;
845 }
846
847 if (lp->chan_state != orig_state)
848 goto out;
849
850 while (lp->rx_head != lp->rx_tail) {
851 struct ldc_packet *p;
852 unsigned long new;
853 int err;
854
855 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
856
857 switch (p->type) {
858 case LDC_CTRL:
859 err = process_control_frame(lp, p);
860 if (err > 0)
861 event_mask |= err;
862 break;
863
864 case LDC_DATA:
865 event_mask |= LDC_EVENT_DATA_READY;
866 err = 0;
867 break;
868
869 case LDC_ERR:
870 err = process_error_frame(lp, p);
871 break;
872
873 default:
874 err = ldc_abort(lp);
875 break;
876 }
877
878 if (err < 0)
879 break;
880
881 new = lp->rx_head;
882 new += LDC_PACKET_SIZE;
883 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
884 new = 0;
885 lp->rx_head = new;
886
887 err = __set_rx_head(lp, new);
888 if (err < 0) {
889 (void) ldc_abort(lp);
890 break;
891 }
892 if (lp->hs_state == LDC_HS_COMPLETE)
893 goto handshake_complete;
894 }
895
896 out:
897 spin_unlock_irqrestore(&lp->lock, flags);
898
899 send_events(lp, event_mask);
900
901 return IRQ_HANDLED;
902 }
903
904 static irqreturn_t ldc_tx(int irq, void *dev_id)
905 {
906 struct ldc_channel *lp = dev_id;
907 unsigned long flags, hv_err, orig_state;
908 unsigned int event_mask = 0;
909
910 spin_lock_irqsave(&lp->lock, flags);
911
912 orig_state = lp->chan_state;
913 hv_err = sun4v_ldc_tx_get_state(lp->id,
914 &lp->tx_head,
915 &lp->tx_tail,
916 &lp->chan_state);
917
918 ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
919 orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
920
921 if (lp->cfg.mode == LDC_MODE_RAW &&
922 lp->chan_state == LDC_CHANNEL_UP) {
923 lp->hs_state = LDC_HS_COMPLETE;
924 ldc_set_state(lp, LDC_STATE_CONNECTED);
925
926 event_mask |= LDC_EVENT_UP;
927 }
928
929 spin_unlock_irqrestore(&lp->lock, flags);
930
931 send_events(lp, event_mask);
932
933 return IRQ_HANDLED;
934 }
935
936 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
937 * XXX that addition and removal from the ldc_channel_list has
938 * XXX atomicity, otherwise the __ldc_channel_exists() check is
939 * XXX totally pointless as another thread can slip into ldc_alloc()
940 * XXX and add a channel with the same ID. There also needs to be
941 * XXX a spinlock for ldc_channel_list.
942 */
943 static HLIST_HEAD(ldc_channel_list);
944
945 static int __ldc_channel_exists(unsigned long id)
946 {
947 struct ldc_channel *lp;
948 struct hlist_node *n;
949
950 hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
951 if (lp->id == id)
952 return 1;
953 }
954 return 0;
955 }
956
957 static int alloc_queue(const char *name, unsigned long num_entries,
958 struct ldc_packet **base, unsigned long *ra)
959 {
960 unsigned long size, order;
961 void *q;
962
963 size = num_entries * LDC_PACKET_SIZE;
964 order = get_order(size);
965
966 q = (void *) __get_free_pages(GFP_KERNEL, order);
967 if (!q) {
968 printk(KERN_ERR PFX "Alloc of %s queue failed with "
969 "size=%lu order=%lu\n", name, size, order);
970 return -ENOMEM;
971 }
972
973 memset(q, 0, PAGE_SIZE << order);
974
975 *base = q;
976 *ra = __pa(q);
977
978 return 0;
979 }
980
981 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
982 {
983 unsigned long size, order;
984
985 if (!q)
986 return;
987
988 size = num_entries * LDC_PACKET_SIZE;
989 order = get_order(size);
990
991 free_pages((unsigned long)q, order);
992 }
993
994 /* XXX Make this configurable... XXX */
995 #define LDC_IOTABLE_SIZE (8 * 1024)
996
997 static int ldc_iommu_init(struct ldc_channel *lp)
998 {
999 unsigned long sz, num_tsb_entries, tsbsize, order;
1000 struct ldc_iommu *iommu = &lp->iommu;
1001 struct ldc_mtable_entry *table;
1002 unsigned long hv_err;
1003 int err;
1004
1005 num_tsb_entries = LDC_IOTABLE_SIZE;
1006 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1007
1008 spin_lock_init(&iommu->lock);
1009
1010 sz = num_tsb_entries / 8;
1011 sz = (sz + 7UL) & ~7UL;
1012 iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1013 if (!iommu->arena.map) {
1014 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1015 return -ENOMEM;
1016 }
1017
1018 iommu->arena.limit = num_tsb_entries;
1019
1020 order = get_order(tsbsize);
1021
1022 table = (struct ldc_mtable_entry *)
1023 __get_free_pages(GFP_KERNEL, order);
1024 err = -ENOMEM;
1025 if (!table) {
1026 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1027 "size=%lu order=%lu\n", tsbsize, order);
1028 goto out_free_map;
1029 }
1030
1031 memset(table, 0, PAGE_SIZE << order);
1032
1033 iommu->page_table = table;
1034
1035 hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1036 num_tsb_entries);
1037 err = -EINVAL;
1038 if (hv_err)
1039 goto out_free_table;
1040
1041 return 0;
1042
1043 out_free_table:
1044 free_pages((unsigned long) table, order);
1045 iommu->page_table = NULL;
1046
1047 out_free_map:
1048 kfree(iommu->arena.map);
1049 iommu->arena.map = NULL;
1050
1051 return err;
1052 }
1053
1054 static void ldc_iommu_release(struct ldc_channel *lp)
1055 {
1056 struct ldc_iommu *iommu = &lp->iommu;
1057 unsigned long num_tsb_entries, tsbsize, order;
1058
1059 (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1060
1061 num_tsb_entries = iommu->arena.limit;
1062 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1063 order = get_order(tsbsize);
1064
1065 free_pages((unsigned long) iommu->page_table, order);
1066 iommu->page_table = NULL;
1067
1068 kfree(iommu->arena.map);
1069 iommu->arena.map = NULL;
1070 }
1071
1072 struct ldc_channel *ldc_alloc(unsigned long id,
1073 const struct ldc_channel_config *cfgp,
1074 void *event_arg)
1075 {
1076 struct ldc_channel *lp;
1077 const struct ldc_mode_ops *mops;
1078 unsigned long dummy1, dummy2, hv_err;
1079 u8 mss, *mssbuf;
1080 int err;
1081
1082 err = -ENODEV;
1083 if (!ldom_domaining_enabled)
1084 goto out_err;
1085
1086 err = -EINVAL;
1087 if (!cfgp)
1088 goto out_err;
1089
1090 switch (cfgp->mode) {
1091 case LDC_MODE_RAW:
1092 mops = &raw_ops;
1093 mss = LDC_PACKET_SIZE;
1094 break;
1095
1096 case LDC_MODE_UNRELIABLE:
1097 mops = &nonraw_ops;
1098 mss = LDC_PACKET_SIZE - 8;
1099 break;
1100
1101 case LDC_MODE_STREAM:
1102 mops = &stream_ops;
1103 mss = LDC_PACKET_SIZE - 8 - 8;
1104 break;
1105
1106 default:
1107 goto out_err;
1108 }
1109
1110 if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1111 goto out_err;
1112
1113 hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1114 err = -ENODEV;
1115 if (hv_err == HV_ECHANNEL)
1116 goto out_err;
1117
1118 err = -EEXIST;
1119 if (__ldc_channel_exists(id))
1120 goto out_err;
1121
1122 mssbuf = NULL;
1123
1124 lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1125 err = -ENOMEM;
1126 if (!lp)
1127 goto out_err;
1128
1129 spin_lock_init(&lp->lock);
1130
1131 lp->id = id;
1132
1133 err = ldc_iommu_init(lp);
1134 if (err)
1135 goto out_free_ldc;
1136
1137 lp->mops = mops;
1138 lp->mss = mss;
1139
1140 lp->cfg = *cfgp;
1141 if (!lp->cfg.mtu)
1142 lp->cfg.mtu = LDC_DEFAULT_MTU;
1143
1144 if (lp->cfg.mode == LDC_MODE_STREAM) {
1145 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1146 if (!mssbuf) {
1147 err = -ENOMEM;
1148 goto out_free_iommu;
1149 }
1150 lp->mssbuf = mssbuf;
1151 }
1152
1153 lp->event_arg = event_arg;
1154
1155 /* XXX allow setting via ldc_channel_config to override defaults
1156 * XXX or use some formula based upon mtu
1157 */
1158 lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1159 lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1160
1161 err = alloc_queue("TX", lp->tx_num_entries,
1162 &lp->tx_base, &lp->tx_ra);
1163 if (err)
1164 goto out_free_mssbuf;
1165
1166 err = alloc_queue("RX", lp->rx_num_entries,
1167 &lp->rx_base, &lp->rx_ra);
1168 if (err)
1169 goto out_free_txq;
1170
1171 lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1172
1173 lp->hs_state = LDC_HS_CLOSED;
1174 ldc_set_state(lp, LDC_STATE_INIT);
1175
1176 INIT_HLIST_NODE(&lp->list);
1177 hlist_add_head(&lp->list, &ldc_channel_list);
1178
1179 INIT_HLIST_HEAD(&lp->mh_list);
1180
1181 return lp;
1182
1183 out_free_txq:
1184 free_queue(lp->tx_num_entries, lp->tx_base);
1185
1186 out_free_mssbuf:
1187 kfree(mssbuf);
1188
1189 out_free_iommu:
1190 ldc_iommu_release(lp);
1191
1192 out_free_ldc:
1193 kfree(lp);
1194
1195 out_err:
1196 return ERR_PTR(err);
1197 }
1198 EXPORT_SYMBOL(ldc_alloc);
1199
1200 void ldc_free(struct ldc_channel *lp)
1201 {
1202 if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1203 free_irq(lp->cfg.rx_irq, lp);
1204 free_irq(lp->cfg.tx_irq, lp);
1205 }
1206
1207 if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1208 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1209 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1210 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1211 }
1212 if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1213 free_queue(lp->tx_num_entries, lp->tx_base);
1214 free_queue(lp->rx_num_entries, lp->rx_base);
1215 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1216 }
1217
1218 hlist_del(&lp->list);
1219
1220 kfree(lp->mssbuf);
1221
1222 ldc_iommu_release(lp);
1223
1224 kfree(lp);
1225 }
1226 EXPORT_SYMBOL(ldc_free);
1227
1228 /* Bind the channel. This registers the LDC queues with
1229 * the hypervisor and puts the channel into a pseudo-listening
1230 * state. This does not initiate a handshake, ldc_connect() does
1231 * that.
1232 */
1233 int ldc_bind(struct ldc_channel *lp, const char *name)
1234 {
1235 unsigned long hv_err, flags;
1236 int err = -EINVAL;
1237
1238 if (!name ||
1239 (lp->state != LDC_STATE_INIT))
1240 return -EINVAL;
1241
1242 snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1243 snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1244
1245 err = request_irq(lp->cfg.rx_irq, ldc_rx,
1246 IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1247 lp->rx_irq_name, lp);
1248 if (err)
1249 return err;
1250
1251 err = request_irq(lp->cfg.tx_irq, ldc_tx,
1252 IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1253 lp->tx_irq_name, lp);
1254 if (err) {
1255 free_irq(lp->cfg.rx_irq, lp);
1256 return err;
1257 }
1258
1259
1260 spin_lock_irqsave(&lp->lock, flags);
1261
1262 enable_irq(lp->cfg.rx_irq);
1263 enable_irq(lp->cfg.tx_irq);
1264
1265 lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1266
1267 err = -ENODEV;
1268 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1269 if (hv_err)
1270 goto out_free_irqs;
1271
1272 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1273 if (hv_err)
1274 goto out_free_irqs;
1275
1276 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1277 if (hv_err)
1278 goto out_unmap_tx;
1279
1280 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1281 if (hv_err)
1282 goto out_unmap_tx;
1283
1284 lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1285
1286 hv_err = sun4v_ldc_tx_get_state(lp->id,
1287 &lp->tx_head,
1288 &lp->tx_tail,
1289 &lp->chan_state);
1290 err = -EBUSY;
1291 if (hv_err)
1292 goto out_unmap_rx;
1293
1294 lp->tx_acked = lp->tx_head;
1295
1296 lp->hs_state = LDC_HS_OPEN;
1297 ldc_set_state(lp, LDC_STATE_BOUND);
1298
1299 spin_unlock_irqrestore(&lp->lock, flags);
1300
1301 return 0;
1302
1303 out_unmap_rx:
1304 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1305 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1306
1307 out_unmap_tx:
1308 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1309
1310 out_free_irqs:
1311 lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1312 free_irq(lp->cfg.tx_irq, lp);
1313 free_irq(lp->cfg.rx_irq, lp);
1314
1315 spin_unlock_irqrestore(&lp->lock, flags);
1316
1317 return err;
1318 }
1319 EXPORT_SYMBOL(ldc_bind);
1320
1321 int ldc_connect(struct ldc_channel *lp)
1322 {
1323 unsigned long flags;
1324 int err;
1325
1326 if (lp->cfg.mode == LDC_MODE_RAW)
1327 return -EINVAL;
1328
1329 spin_lock_irqsave(&lp->lock, flags);
1330
1331 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1332 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1333 lp->hs_state != LDC_HS_OPEN)
1334 err = -EINVAL;
1335 else
1336 err = start_handshake(lp);
1337
1338 spin_unlock_irqrestore(&lp->lock, flags);
1339
1340 return err;
1341 }
1342 EXPORT_SYMBOL(ldc_connect);
1343
1344 int ldc_disconnect(struct ldc_channel *lp)
1345 {
1346 unsigned long hv_err, flags;
1347 int err;
1348
1349 if (lp->cfg.mode == LDC_MODE_RAW)
1350 return -EINVAL;
1351
1352 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1353 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1354 return -EINVAL;
1355
1356 spin_lock_irqsave(&lp->lock, flags);
1357
1358 err = -ENODEV;
1359 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1360 if (hv_err)
1361 goto out_err;
1362
1363 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1364 if (hv_err)
1365 goto out_err;
1366
1367 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1368 if (hv_err)
1369 goto out_err;
1370
1371 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1372 if (hv_err)
1373 goto out_err;
1374
1375 ldc_set_state(lp, LDC_STATE_BOUND);
1376 lp->hs_state = LDC_HS_OPEN;
1377 lp->flags |= LDC_FLAG_RESET;
1378
1379 spin_unlock_irqrestore(&lp->lock, flags);
1380
1381 return 0;
1382
1383 out_err:
1384 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1385 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1386 free_irq(lp->cfg.tx_irq, lp);
1387 free_irq(lp->cfg.rx_irq, lp);
1388 lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1389 LDC_FLAG_REGISTERED_QUEUES);
1390 ldc_set_state(lp, LDC_STATE_INIT);
1391
1392 spin_unlock_irqrestore(&lp->lock, flags);
1393
1394 return err;
1395 }
1396 EXPORT_SYMBOL(ldc_disconnect);
1397
1398 int ldc_state(struct ldc_channel *lp)
1399 {
1400 return lp->state;
1401 }
1402 EXPORT_SYMBOL(ldc_state);
1403
1404 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1405 {
1406 struct ldc_packet *p;
1407 unsigned long new_tail;
1408 int err;
1409
1410 if (size > LDC_PACKET_SIZE)
1411 return -EMSGSIZE;
1412
1413 p = data_get_tx_packet(lp, &new_tail);
1414 if (!p)
1415 return -EAGAIN;
1416
1417 memcpy(p, buf, size);
1418
1419 err = send_tx_packet(lp, p, new_tail);
1420 if (!err)
1421 err = size;
1422
1423 return err;
1424 }
1425
1426 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1427 {
1428 struct ldc_packet *p;
1429 unsigned long hv_err, new;
1430 int err;
1431
1432 if (size < LDC_PACKET_SIZE)
1433 return -EINVAL;
1434
1435 hv_err = sun4v_ldc_rx_get_state(lp->id,
1436 &lp->rx_head,
1437 &lp->rx_tail,
1438 &lp->chan_state);
1439 if (hv_err)
1440 return ldc_abort(lp);
1441
1442 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1443 lp->chan_state == LDC_CHANNEL_RESETTING)
1444 return -ECONNRESET;
1445
1446 if (lp->rx_head == lp->rx_tail)
1447 return 0;
1448
1449 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1450 memcpy(buf, p, LDC_PACKET_SIZE);
1451
1452 new = rx_advance(lp, lp->rx_head);
1453 lp->rx_head = new;
1454
1455 err = __set_rx_head(lp, new);
1456 if (err < 0)
1457 err = -ECONNRESET;
1458 else
1459 err = LDC_PACKET_SIZE;
1460
1461 return err;
1462 }
1463
1464 static const struct ldc_mode_ops raw_ops = {
1465 .write = write_raw,
1466 .read = read_raw,
1467 };
1468
1469 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1470 unsigned int size)
1471 {
1472 unsigned long hv_err, tail;
1473 unsigned int copied;
1474 u32 seq;
1475 int err;
1476
1477 hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1478 &lp->chan_state);
1479 if (unlikely(hv_err))
1480 return -EBUSY;
1481
1482 if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1483 return ldc_abort(lp);
1484
1485 if (!tx_has_space_for(lp, size))
1486 return -EAGAIN;
1487
1488 seq = lp->snd_nxt;
1489 copied = 0;
1490 tail = lp->tx_tail;
1491 while (copied < size) {
1492 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1493 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1494 p->u.u_data :
1495 p->u.r.r_data);
1496 int data_len;
1497
1498 p->type = LDC_DATA;
1499 p->stype = LDC_INFO;
1500 p->ctrl = 0;
1501
1502 data_len = size - copied;
1503 if (data_len > lp->mss)
1504 data_len = lp->mss;
1505
1506 BUG_ON(data_len > LDC_LEN);
1507
1508 p->env = (data_len |
1509 (copied == 0 ? LDC_START : 0) |
1510 (data_len == size - copied ? LDC_STOP : 0));
1511
1512 p->seqid = ++seq;
1513
1514 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1515 p->type,
1516 p->stype,
1517 p->ctrl,
1518 p->env,
1519 p->seqid);
1520
1521 memcpy(data, buf, data_len);
1522 buf += data_len;
1523 copied += data_len;
1524
1525 tail = tx_advance(lp, tail);
1526 }
1527
1528 err = set_tx_tail(lp, tail);
1529 if (!err) {
1530 lp->snd_nxt = seq;
1531 err = size;
1532 }
1533
1534 return err;
1535 }
1536
1537 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1538 struct ldc_packet *first_frag)
1539 {
1540 int err;
1541
1542 if (first_frag)
1543 lp->rcv_nxt = first_frag->seqid - 1;
1544
1545 err = send_data_nack(lp, p);
1546 if (err)
1547 return err;
1548
1549 err = __set_rx_head(lp, lp->rx_tail);
1550 if (err < 0)
1551 return ldc_abort(lp);
1552
1553 return 0;
1554 }
1555
1556 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1557 {
1558 if (p->stype & LDC_ACK) {
1559 int err = process_data_ack(lp, p);
1560 if (err)
1561 return err;
1562 }
1563 if (p->stype & LDC_NACK)
1564 return ldc_abort(lp);
1565
1566 return 0;
1567 }
1568
1569 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1570 {
1571 unsigned long dummy;
1572 int limit = 1000;
1573
1574 ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1575 cur_head, lp->rx_head, lp->rx_tail);
1576 while (limit-- > 0) {
1577 unsigned long hv_err;
1578
1579 hv_err = sun4v_ldc_rx_get_state(lp->id,
1580 &dummy,
1581 &lp->rx_tail,
1582 &lp->chan_state);
1583 if (hv_err)
1584 return ldc_abort(lp);
1585
1586 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1587 lp->chan_state == LDC_CHANNEL_RESETTING)
1588 return -ECONNRESET;
1589
1590 if (cur_head != lp->rx_tail) {
1591 ldcdbg(DATA, "DATA WAIT DONE "
1592 "head[%lx] tail[%lx] chan_state[%lx]\n",
1593 dummy, lp->rx_tail, lp->chan_state);
1594 return 0;
1595 }
1596
1597 udelay(1);
1598 }
1599 return -EAGAIN;
1600 }
1601
1602 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1603 {
1604 int err = __set_rx_head(lp, head);
1605
1606 if (err < 0)
1607 return ldc_abort(lp);
1608
1609 lp->rx_head = head;
1610 return 0;
1611 }
1612
1613 static void send_data_ack(struct ldc_channel *lp)
1614 {
1615 unsigned long new_tail;
1616 struct ldc_packet *p;
1617
1618 p = data_get_tx_packet(lp, &new_tail);
1619 if (likely(p)) {
1620 int err;
1621
1622 memset(p, 0, sizeof(*p));
1623 p->type = LDC_DATA;
1624 p->stype = LDC_ACK;
1625 p->ctrl = 0;
1626 p->seqid = lp->snd_nxt + 1;
1627 p->u.r.ackid = lp->rcv_nxt;
1628
1629 err = send_tx_packet(lp, p, new_tail);
1630 if (!err)
1631 lp->snd_nxt++;
1632 }
1633 }
1634
1635 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1636 {
1637 struct ldc_packet *first_frag;
1638 unsigned long hv_err, new;
1639 int err, copied;
1640
1641 hv_err = sun4v_ldc_rx_get_state(lp->id,
1642 &lp->rx_head,
1643 &lp->rx_tail,
1644 &lp->chan_state);
1645 if (hv_err)
1646 return ldc_abort(lp);
1647
1648 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1649 lp->chan_state == LDC_CHANNEL_RESETTING)
1650 return -ECONNRESET;
1651
1652 if (lp->rx_head == lp->rx_tail)
1653 return 0;
1654
1655 first_frag = NULL;
1656 copied = err = 0;
1657 new = lp->rx_head;
1658 while (1) {
1659 struct ldc_packet *p;
1660 int pkt_len;
1661
1662 BUG_ON(new == lp->rx_tail);
1663 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1664
1665 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1666 "rcv_nxt[%08x]\n",
1667 p->type,
1668 p->stype,
1669 p->ctrl,
1670 p->env,
1671 p->seqid,
1672 p->u.r.ackid,
1673 lp->rcv_nxt);
1674
1675 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1676 err = rx_bad_seq(lp, p, first_frag);
1677 copied = 0;
1678 break;
1679 }
1680
1681 if (p->type & LDC_CTRL) {
1682 err = process_control_frame(lp, p);
1683 if (err < 0)
1684 break;
1685 err = 0;
1686 }
1687
1688 lp->rcv_nxt = p->seqid;
1689
1690 if (!(p->type & LDC_DATA)) {
1691 new = rx_advance(lp, new);
1692 goto no_data;
1693 }
1694 if (p->stype & (LDC_ACK | LDC_NACK)) {
1695 err = data_ack_nack(lp, p);
1696 if (err)
1697 break;
1698 }
1699 if (!(p->stype & LDC_INFO)) {
1700 new = rx_advance(lp, new);
1701 err = rx_set_head(lp, new);
1702 if (err)
1703 break;
1704 goto no_data;
1705 }
1706
1707 pkt_len = p->env & LDC_LEN;
1708
1709 /* Every initial packet starts with the START bit set.
1710 *
1711 * Singleton packets will have both START+STOP set.
1712 *
1713 * Fragments will have START set in the first frame, STOP
1714 * set in the last frame, and neither bit set in middle
1715 * frames of the packet.
1716 *
1717 * Therefore if we are at the beginning of a packet and
1718 * we don't see START, or we are in the middle of a fragmented
1719 * packet and do see START, we are unsynchronized and should
1720 * flush the RX queue.
1721 */
1722 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1723 (first_frag != NULL && (p->env & LDC_START))) {
1724 if (!first_frag)
1725 new = rx_advance(lp, new);
1726
1727 err = rx_set_head(lp, new);
1728 if (err)
1729 break;
1730
1731 if (!first_frag)
1732 goto no_data;
1733 }
1734 if (!first_frag)
1735 first_frag = p;
1736
1737 if (pkt_len > size - copied) {
1738 /* User didn't give us a big enough buffer,
1739 * what to do? This is a pretty serious error.
1740 *
1741 * Since we haven't updated the RX ring head to
1742 * consume any of the packets, signal the error
1743 * to the user and just leave the RX ring alone.
1744 *
1745 * This seems the best behavior because this allows
1746 * a user of the LDC layer to start with a small
1747 * RX buffer for ldc_read() calls and use -EMSGSIZE
1748 * as a cue to enlarge it's read buffer.
1749 */
1750 err = -EMSGSIZE;
1751 break;
1752 }
1753
1754 /* Ok, we are gonna eat this one. */
1755 new = rx_advance(lp, new);
1756
1757 memcpy(buf,
1758 (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1759 p->u.u_data : p->u.r.r_data), pkt_len);
1760 buf += pkt_len;
1761 copied += pkt_len;
1762
1763 if (p->env & LDC_STOP)
1764 break;
1765
1766 no_data:
1767 if (new == lp->rx_tail) {
1768 err = rx_data_wait(lp, new);
1769 if (err)
1770 break;
1771 }
1772 }
1773
1774 if (!err)
1775 err = rx_set_head(lp, new);
1776
1777 if (err && first_frag)
1778 lp->rcv_nxt = first_frag->seqid - 1;
1779
1780 if (!err) {
1781 err = copied;
1782 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1783 send_data_ack(lp);
1784 }
1785
1786 return err;
1787 }
1788
1789 static const struct ldc_mode_ops nonraw_ops = {
1790 .write = write_nonraw,
1791 .read = read_nonraw,
1792 };
1793
1794 static int write_stream(struct ldc_channel *lp, const void *buf,
1795 unsigned int size)
1796 {
1797 if (size > lp->cfg.mtu)
1798 size = lp->cfg.mtu;
1799 return write_nonraw(lp, buf, size);
1800 }
1801
1802 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1803 {
1804 if (!lp->mssbuf_len) {
1805 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1806 if (err < 0)
1807 return err;
1808
1809 lp->mssbuf_len = err;
1810 lp->mssbuf_off = 0;
1811 }
1812
1813 if (size > lp->mssbuf_len)
1814 size = lp->mssbuf_len;
1815 memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1816
1817 lp->mssbuf_off += size;
1818 lp->mssbuf_len -= size;
1819
1820 return size;
1821 }
1822
1823 static const struct ldc_mode_ops stream_ops = {
1824 .write = write_stream,
1825 .read = read_stream,
1826 };
1827
1828 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1829 {
1830 unsigned long flags;
1831 int err;
1832
1833 if (!buf)
1834 return -EINVAL;
1835
1836 if (!size)
1837 return 0;
1838
1839 spin_lock_irqsave(&lp->lock, flags);
1840
1841 if (lp->hs_state != LDC_HS_COMPLETE)
1842 err = -ENOTCONN;
1843 else
1844 err = lp->mops->write(lp, buf, size);
1845
1846 spin_unlock_irqrestore(&lp->lock, flags);
1847
1848 return err;
1849 }
1850 EXPORT_SYMBOL(ldc_write);
1851
1852 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1853 {
1854 unsigned long flags;
1855 int err;
1856
1857 if (!buf)
1858 return -EINVAL;
1859
1860 if (!size)
1861 return 0;
1862
1863 spin_lock_irqsave(&lp->lock, flags);
1864
1865 if (lp->hs_state != LDC_HS_COMPLETE)
1866 err = -ENOTCONN;
1867 else
1868 err = lp->mops->read(lp, buf, size);
1869
1870 spin_unlock_irqrestore(&lp->lock, flags);
1871
1872 return err;
1873 }
1874 EXPORT_SYMBOL(ldc_read);
1875
1876 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1877 {
1878 struct iommu_arena *arena = &iommu->arena;
1879 unsigned long n, start, end, limit;
1880 int pass;
1881
1882 limit = arena->limit;
1883 start = arena->hint;
1884 pass = 0;
1885
1886 again:
1887 n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1888 end = n + npages;
1889 if (unlikely(end >= limit)) {
1890 if (likely(pass < 1)) {
1891 limit = start;
1892 start = 0;
1893 pass++;
1894 goto again;
1895 } else {
1896 /* Scanned the whole thing, give up. */
1897 return -1;
1898 }
1899 }
1900 bitmap_set(arena->map, n, npages);
1901
1902 arena->hint = end;
1903
1904 return n;
1905 }
1906
1907 #define COOKIE_PGSZ_CODE 0xf000000000000000ULL
1908 #define COOKIE_PGSZ_CODE_SHIFT 60ULL
1909
1910 static u64 pagesize_code(void)
1911 {
1912 switch (PAGE_SIZE) {
1913 default:
1914 case (8ULL * 1024ULL):
1915 return 0;
1916 case (64ULL * 1024ULL):
1917 return 1;
1918 case (512ULL * 1024ULL):
1919 return 2;
1920 case (4ULL * 1024ULL * 1024ULL):
1921 return 3;
1922 case (32ULL * 1024ULL * 1024ULL):
1923 return 4;
1924 case (256ULL * 1024ULL * 1024ULL):
1925 return 5;
1926 }
1927 }
1928
1929 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1930 {
1931 return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1932 (index << PAGE_SHIFT) |
1933 page_offset);
1934 }
1935
1936 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1937 {
1938 u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1939
1940 cookie &= ~COOKIE_PGSZ_CODE;
1941
1942 *shift = szcode * 3;
1943
1944 return (cookie >> (13ULL + (szcode * 3ULL)));
1945 }
1946
1947 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1948 unsigned long npages)
1949 {
1950 long entry;
1951
1952 entry = arena_alloc(iommu, npages);
1953 if (unlikely(entry < 0))
1954 return NULL;
1955
1956 return iommu->page_table + entry;
1957 }
1958
1959 static u64 perm_to_mte(unsigned int map_perm)
1960 {
1961 u64 mte_base;
1962
1963 mte_base = pagesize_code();
1964
1965 if (map_perm & LDC_MAP_SHADOW) {
1966 if (map_perm & LDC_MAP_R)
1967 mte_base |= LDC_MTE_COPY_R;
1968 if (map_perm & LDC_MAP_W)
1969 mte_base |= LDC_MTE_COPY_W;
1970 }
1971 if (map_perm & LDC_MAP_DIRECT) {
1972 if (map_perm & LDC_MAP_R)
1973 mte_base |= LDC_MTE_READ;
1974 if (map_perm & LDC_MAP_W)
1975 mte_base |= LDC_MTE_WRITE;
1976 if (map_perm & LDC_MAP_X)
1977 mte_base |= LDC_MTE_EXEC;
1978 }
1979 if (map_perm & LDC_MAP_IO) {
1980 if (map_perm & LDC_MAP_R)
1981 mte_base |= LDC_MTE_IOMMU_R;
1982 if (map_perm & LDC_MAP_W)
1983 mte_base |= LDC_MTE_IOMMU_W;
1984 }
1985
1986 return mte_base;
1987 }
1988
1989 static int pages_in_region(unsigned long base, long len)
1990 {
1991 int count = 0;
1992
1993 do {
1994 unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
1995
1996 len -= (new - base);
1997 base = new;
1998 count++;
1999 } while (len > 0);
2000
2001 return count;
2002 }
2003
2004 struct cookie_state {
2005 struct ldc_mtable_entry *page_table;
2006 struct ldc_trans_cookie *cookies;
2007 u64 mte_base;
2008 u64 prev_cookie;
2009 u32 pte_idx;
2010 u32 nc;
2011 };
2012
2013 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2014 unsigned long off, unsigned long len)
2015 {
2016 do {
2017 unsigned long tlen, new = pa + PAGE_SIZE;
2018 u64 this_cookie;
2019
2020 sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2021
2022 tlen = PAGE_SIZE;
2023 if (off)
2024 tlen = PAGE_SIZE - off;
2025 if (tlen > len)
2026 tlen = len;
2027
2028 this_cookie = make_cookie(sp->pte_idx,
2029 pagesize_code(), off);
2030
2031 off = 0;
2032
2033 if (this_cookie == sp->prev_cookie) {
2034 sp->cookies[sp->nc - 1].cookie_size += tlen;
2035 } else {
2036 sp->cookies[sp->nc].cookie_addr = this_cookie;
2037 sp->cookies[sp->nc].cookie_size = tlen;
2038 sp->nc++;
2039 }
2040 sp->prev_cookie = this_cookie + tlen;
2041
2042 sp->pte_idx++;
2043
2044 len -= tlen;
2045 pa = new;
2046 } while (len > 0);
2047 }
2048
2049 static int sg_count_one(struct scatterlist *sg)
2050 {
2051 unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2052 long len = sg->length;
2053
2054 if ((sg->offset | len) & (8UL - 1))
2055 return -EFAULT;
2056
2057 return pages_in_region(base + sg->offset, len);
2058 }
2059
2060 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2061 {
2062 int count;
2063 int i;
2064
2065 count = 0;
2066 for (i = 0; i < num_sg; i++) {
2067 int err = sg_count_one(sg + i);
2068 if (err < 0)
2069 return err;
2070 count += err;
2071 }
2072
2073 return count;
2074 }
2075
2076 int ldc_map_sg(struct ldc_channel *lp,
2077 struct scatterlist *sg, int num_sg,
2078 struct ldc_trans_cookie *cookies, int ncookies,
2079 unsigned int map_perm)
2080 {
2081 unsigned long i, npages, flags;
2082 struct ldc_mtable_entry *base;
2083 struct cookie_state state;
2084 struct ldc_iommu *iommu;
2085 int err;
2086
2087 if (map_perm & ~LDC_MAP_ALL)
2088 return -EINVAL;
2089
2090 err = sg_count_pages(sg, num_sg);
2091 if (err < 0)
2092 return err;
2093
2094 npages = err;
2095 if (err > ncookies)
2096 return -EMSGSIZE;
2097
2098 iommu = &lp->iommu;
2099
2100 spin_lock_irqsave(&iommu->lock, flags);
2101 base = alloc_npages(iommu, npages);
2102 spin_unlock_irqrestore(&iommu->lock, flags);
2103
2104 if (!base)
2105 return -ENOMEM;
2106
2107 state.page_table = iommu->page_table;
2108 state.cookies = cookies;
2109 state.mte_base = perm_to_mte(map_perm);
2110 state.prev_cookie = ~(u64)0;
2111 state.pte_idx = (base - iommu->page_table);
2112 state.nc = 0;
2113
2114 for (i = 0; i < num_sg; i++)
2115 fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2116 sg[i].offset, sg[i].length);
2117
2118 return state.nc;
2119 }
2120 EXPORT_SYMBOL(ldc_map_sg);
2121
2122 int ldc_map_single(struct ldc_channel *lp,
2123 void *buf, unsigned int len,
2124 struct ldc_trans_cookie *cookies, int ncookies,
2125 unsigned int map_perm)
2126 {
2127 unsigned long npages, pa, flags;
2128 struct ldc_mtable_entry *base;
2129 struct cookie_state state;
2130 struct ldc_iommu *iommu;
2131
2132 if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2133 return -EINVAL;
2134
2135 pa = __pa(buf);
2136 if ((pa | len) & (8UL - 1))
2137 return -EFAULT;
2138
2139 npages = pages_in_region(pa, len);
2140
2141 iommu = &lp->iommu;
2142
2143 spin_lock_irqsave(&iommu->lock, flags);
2144 base = alloc_npages(iommu, npages);
2145 spin_unlock_irqrestore(&iommu->lock, flags);
2146
2147 if (!base)
2148 return -ENOMEM;
2149
2150 state.page_table = iommu->page_table;
2151 state.cookies = cookies;
2152 state.mte_base = perm_to_mte(map_perm);
2153 state.prev_cookie = ~(u64)0;
2154 state.pte_idx = (base - iommu->page_table);
2155 state.nc = 0;
2156 fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2157 BUG_ON(state.nc != 1);
2158
2159 return state.nc;
2160 }
2161 EXPORT_SYMBOL(ldc_map_single);
2162
2163 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2164 u64 cookie, u64 size)
2165 {
2166 struct iommu_arena *arena = &iommu->arena;
2167 unsigned long i, shift, index, npages;
2168 struct ldc_mtable_entry *base;
2169
2170 npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2171 index = cookie_to_index(cookie, &shift);
2172 base = iommu->page_table + index;
2173
2174 BUG_ON(index > arena->limit ||
2175 (index + npages) > arena->limit);
2176
2177 for (i = 0; i < npages; i++) {
2178 if (base->cookie)
2179 sun4v_ldc_revoke(id, cookie + (i << shift),
2180 base->cookie);
2181 base->mte = 0;
2182 __clear_bit(index + i, arena->map);
2183 }
2184 }
2185
2186 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2187 int ncookies)
2188 {
2189 struct ldc_iommu *iommu = &lp->iommu;
2190 unsigned long flags;
2191 int i;
2192
2193 spin_lock_irqsave(&iommu->lock, flags);
2194 for (i = 0; i < ncookies; i++) {
2195 u64 addr = cookies[i].cookie_addr;
2196 u64 size = cookies[i].cookie_size;
2197
2198 free_npages(lp->id, iommu, addr, size);
2199 }
2200 spin_unlock_irqrestore(&iommu->lock, flags);
2201 }
2202 EXPORT_SYMBOL(ldc_unmap);
2203
2204 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2205 void *buf, unsigned int len, unsigned long offset,
2206 struct ldc_trans_cookie *cookies, int ncookies)
2207 {
2208 unsigned int orig_len;
2209 unsigned long ra;
2210 int i;
2211
2212 if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2213 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2214 lp->id, copy_dir);
2215 return -EINVAL;
2216 }
2217
2218 ra = __pa(buf);
2219 if ((ra | len | offset) & (8UL - 1)) {
2220 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2221 "ra[%lx] len[%x] offset[%lx]\n",
2222 lp->id, ra, len, offset);
2223 return -EFAULT;
2224 }
2225
2226 if (lp->hs_state != LDC_HS_COMPLETE ||
2227 (lp->flags & LDC_FLAG_RESET)) {
2228 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2229 "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2230 return -ECONNRESET;
2231 }
2232
2233 orig_len = len;
2234 for (i = 0; i < ncookies; i++) {
2235 unsigned long cookie_raddr = cookies[i].cookie_addr;
2236 unsigned long this_len = cookies[i].cookie_size;
2237 unsigned long actual_len;
2238
2239 if (unlikely(offset)) {
2240 unsigned long this_off = offset;
2241
2242 if (this_off > this_len)
2243 this_off = this_len;
2244
2245 offset -= this_off;
2246 this_len -= this_off;
2247 if (!this_len)
2248 continue;
2249 cookie_raddr += this_off;
2250 }
2251
2252 if (this_len > len)
2253 this_len = len;
2254
2255 while (1) {
2256 unsigned long hv_err;
2257
2258 hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2259 cookie_raddr, ra,
2260 this_len, &actual_len);
2261 if (unlikely(hv_err)) {
2262 printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2263 "HV error %lu\n",
2264 lp->id, hv_err);
2265 if (lp->hs_state != LDC_HS_COMPLETE ||
2266 (lp->flags & LDC_FLAG_RESET))
2267 return -ECONNRESET;
2268 else
2269 return -EFAULT;
2270 }
2271
2272 cookie_raddr += actual_len;
2273 ra += actual_len;
2274 len -= actual_len;
2275 if (actual_len == this_len)
2276 break;
2277
2278 this_len -= actual_len;
2279 }
2280
2281 if (!len)
2282 break;
2283 }
2284
2285 /* It is caller policy what to do about short copies.
2286 * For example, a networking driver can declare the
2287 * packet a runt and drop it.
2288 */
2289
2290 return orig_len - len;
2291 }
2292 EXPORT_SYMBOL(ldc_copy);
2293
2294 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2295 struct ldc_trans_cookie *cookies, int *ncookies,
2296 unsigned int map_perm)
2297 {
2298 void *buf;
2299 int err;
2300
2301 if (len & (8UL - 1))
2302 return ERR_PTR(-EINVAL);
2303
2304 buf = kzalloc(len, GFP_KERNEL);
2305 if (!buf)
2306 return ERR_PTR(-ENOMEM);
2307
2308 err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2309 if (err < 0) {
2310 kfree(buf);
2311 return ERR_PTR(err);
2312 }
2313 *ncookies = err;
2314
2315 return buf;
2316 }
2317 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2318
2319 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2320 struct ldc_trans_cookie *cookies, int ncookies)
2321 {
2322 ldc_unmap(lp, cookies, ncookies);
2323 kfree(buf);
2324 }
2325 EXPORT_SYMBOL(ldc_free_exp_dring);
2326
2327 static int __init ldc_init(void)
2328 {
2329 unsigned long major, minor;
2330 struct mdesc_handle *hp;
2331 const u64 *v;
2332 int err;
2333 u64 mp;
2334
2335 hp = mdesc_grab();
2336 if (!hp)
2337 return -ENODEV;
2338
2339 mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2340 err = -ENODEV;
2341 if (mp == MDESC_NODE_NULL)
2342 goto out;
2343
2344 v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2345 if (!v)
2346 goto out;
2347
2348 major = 1;
2349 minor = 0;
2350 if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2351 printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2352 goto out;
2353 }
2354
2355 printk(KERN_INFO "%s", version);
2356
2357 if (!*v) {
2358 printk(KERN_INFO PFX "Domaining disabled.\n");
2359 goto out;
2360 }
2361 ldom_domaining_enabled = 1;
2362 err = 0;
2363
2364 out:
2365 mdesc_release(hp);
2366 return err;
2367 }
2368
2369 core_initcall(ldc_init);
Linux with added FPC-III support