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x86/amd-iommu: Workaround for erratum 63
[linux-2.6/verdex.git] / arch / sparc / kernel / ldc.c
blobcb3c72c45aab441786c6ad5274cfb9aa056f735c
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
18 #include <asm/hypervisor.h>
19 #include <asm/iommu.h>
20 #include <asm/page.h>
21 #include <asm/ldc.h>
22 #include <asm/mdesc.h>
23
24 #define DRV_MODULE_NAME "ldc"
25 #define PFX DRV_MODULE_NAME ": "
26 #define DRV_MODULE_VERSION "1.1"
27 #define DRV_MODULE_RELDATE "July 22, 2008"
28
29 static char version[] __devinitdata =
30 DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
31 #define LDC_PACKET_SIZE 64
32
33 /* Packet header layout for unreliable and reliable mode frames.
34 * When in RAW mode, packets are simply straight 64-byte payloads
35 * with no headers.
36 */
37 struct ldc_packet {
38 u8 type;
39 #define LDC_CTRL 0x01
40 #define LDC_DATA 0x02
41 #define LDC_ERR 0x10
42
43 u8 stype;
44 #define LDC_INFO 0x01
45 #define LDC_ACK 0x02
46 #define LDC_NACK 0x04
47
48 u8 ctrl;
49 #define LDC_VERS 0x01 /* Link Version */
50 #define LDC_RTS 0x02 /* Request To Send */
51 #define LDC_RTR 0x03 /* Ready To Receive */
52 #define LDC_RDX 0x04 /* Ready for Data eXchange */
53 #define LDC_CTRL_MSK 0x0f
54
55 u8 env;
56 #define LDC_LEN 0x3f
57 #define LDC_FRAG_MASK 0xc0
58 #define LDC_START 0x40
59 #define LDC_STOP 0x80
60
61 u32 seqid;
62
63 union {
64 u8 u_data[LDC_PACKET_SIZE - 8];
65 struct {
66 u32 pad;
67 u32 ackid;
68 u8 r_data[LDC_PACKET_SIZE - 8 - 8];
69 } r;
70 } u;
71 };
72
73 struct ldc_version {
74 u16 major;
75 u16 minor;
76 };
77
78 /* Ordered from largest major to lowest. */
79 static struct ldc_version ver_arr[] = {
80 { .major = 1, .minor = 0 },
81 };
82
83 #define LDC_DEFAULT_MTU (4 * LDC_PACKET_SIZE)
84 #define LDC_DEFAULT_NUM_ENTRIES (PAGE_SIZE / LDC_PACKET_SIZE)
85
86 struct ldc_channel;
87
88 struct ldc_mode_ops {
89 int (*write)(struct ldc_channel *, const void *, unsigned int);
90 int (*read)(struct ldc_channel *, void *, unsigned int);
91 };
92
93 static const struct ldc_mode_ops raw_ops;
94 static const struct ldc_mode_ops nonraw_ops;
95 static const struct ldc_mode_ops stream_ops;
96
97 int ldom_domaining_enabled;
98
99 struct ldc_iommu {
100 /* Protects arena alloc/free. */
101 spinlock_t lock;
102 struct iommu_arena arena;
103 struct ldc_mtable_entry *page_table;
104 };
105
106 struct ldc_channel {
107 /* Protects all operations that depend upon channel state. */
108 spinlock_t lock;
109
110 unsigned long id;
111
112 u8 *mssbuf;
113 u32 mssbuf_len;
114 u32 mssbuf_off;
115
116 struct ldc_packet *tx_base;
117 unsigned long tx_head;
118 unsigned long tx_tail;
119 unsigned long tx_num_entries;
120 unsigned long tx_ra;
121
122 unsigned long tx_acked;
123
124 struct ldc_packet *rx_base;
125 unsigned long rx_head;
126 unsigned long rx_tail;
127 unsigned long rx_num_entries;
128 unsigned long rx_ra;
129
130 u32 rcv_nxt;
131 u32 snd_nxt;
132
133 unsigned long chan_state;
134
135 struct ldc_channel_config cfg;
136 void *event_arg;
137
138 const struct ldc_mode_ops *mops;
139
140 struct ldc_iommu iommu;
141
142 struct ldc_version ver;
143
144 u8 hs_state;
145 #define LDC_HS_CLOSED 0x00
146 #define LDC_HS_OPEN 0x01
147 #define LDC_HS_GOTVERS 0x02
148 #define LDC_HS_SENTRTR 0x03
149 #define LDC_HS_GOTRTR 0x04
150 #define LDC_HS_COMPLETE 0x10
151
152 u8 flags;
153 #define LDC_FLAG_ALLOCED_QUEUES 0x01
154 #define LDC_FLAG_REGISTERED_QUEUES 0x02
155 #define LDC_FLAG_REGISTERED_IRQS 0x04
156 #define LDC_FLAG_RESET 0x10
157
158 u8 mss;
159 u8 state;
160
161 #define LDC_IRQ_NAME_MAX 32
162 char rx_irq_name[LDC_IRQ_NAME_MAX];
163 char tx_irq_name[LDC_IRQ_NAME_MAX];
164
165 struct hlist_head mh_list;
166
167 struct hlist_node list;
168 };
169
170 #define ldcdbg(TYPE, f, a...) \
171 do { if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
172 printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
173 } while (0)
174
175 static const char *state_to_str(u8 state)
176 {
177 switch (state) {
178 case LDC_STATE_INVALID:
179 return "INVALID";
180 case LDC_STATE_INIT:
181 return "INIT";
182 case LDC_STATE_BOUND:
183 return "BOUND";
184 case LDC_STATE_READY:
185 return "READY";
186 case LDC_STATE_CONNECTED:
187 return "CONNECTED";
188 default:
189 return "<UNKNOWN>";
190 }
191 }
192
193 static void ldc_set_state(struct ldc_channel *lp, u8 state)
194 {
195 ldcdbg(STATE, "STATE (%s) --> (%s)\n",
196 state_to_str(lp->state),
197 state_to_str(state));
198
199 lp->state = state;
200 }
201
202 static unsigned long __advance(unsigned long off, unsigned long num_entries)
203 {
204 off += LDC_PACKET_SIZE;
205 if (off == (num_entries * LDC_PACKET_SIZE))
206 off = 0;
207
208 return off;
209 }
210
211 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
212 {
213 return __advance(off, lp->rx_num_entries);
214 }
215
216 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
217 {
218 return __advance(off, lp->tx_num_entries);
219 }
220
221 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
222 unsigned long *new_tail)
223 {
224 struct ldc_packet *p;
225 unsigned long t;
226
227 t = tx_advance(lp, lp->tx_tail);
228 if (t == lp->tx_head)
229 return NULL;
230
231 *new_tail = t;
232
233 p = lp->tx_base;
234 return p + (lp->tx_tail / LDC_PACKET_SIZE);
235 }
236
237 /* When we are in reliable or stream mode, have to track the next packet
238 * we haven't gotten an ACK for in the TX queue using tx_acked. We have
239 * to be careful not to stomp over the queue past that point. During
240 * the handshake, we don't have TX data packets pending in the queue
241 * and that's why handshake_get_tx_packet() need not be mindful of
242 * lp->tx_acked.
243 */
244 static unsigned long head_for_data(struct ldc_channel *lp)
245 {
246 if (lp->cfg.mode == LDC_MODE_STREAM)
247 return lp->tx_acked;
248 return lp->tx_head;
249 }
250
251 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
252 {
253 unsigned long limit, tail, new_tail, diff;
254 unsigned int mss;
255
256 limit = head_for_data(lp);
257 tail = lp->tx_tail;
258 new_tail = tx_advance(lp, tail);
259 if (new_tail == limit)
260 return 0;
261
262 if (limit > new_tail)
263 diff = limit - new_tail;
264 else
265 diff = (limit +
266 ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
267 diff /= LDC_PACKET_SIZE;
268 mss = lp->mss;
269
270 if (diff * mss < size)
271 return 0;
272
273 return 1;
274 }
275
276 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
277 unsigned long *new_tail)
278 {
279 struct ldc_packet *p;
280 unsigned long h, t;
281
282 h = head_for_data(lp);
283 t = tx_advance(lp, lp->tx_tail);
284 if (t == h)
285 return NULL;
286
287 *new_tail = t;
288
289 p = lp->tx_base;
290 return p + (lp->tx_tail / LDC_PACKET_SIZE);
291 }
292
293 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
294 {
295 unsigned long orig_tail = lp->tx_tail;
296 int limit = 1000;
297
298 lp->tx_tail = tail;
299 while (limit-- > 0) {
300 unsigned long err;
301
302 err = sun4v_ldc_tx_set_qtail(lp->id, tail);
303 if (!err)
304 return 0;
305
306 if (err != HV_EWOULDBLOCK) {
307 lp->tx_tail = orig_tail;
308 return -EINVAL;
309 }
310 udelay(1);
311 }
312
313 lp->tx_tail = orig_tail;
314 return -EBUSY;
315 }
316
317 /* This just updates the head value in the hypervisor using
318 * a polling loop with a timeout. The caller takes care of
319 * upating software state representing the head change, if any.
320 */
321 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
322 {
323 int limit = 1000;
324
325 while (limit-- > 0) {
326 unsigned long err;
327
328 err = sun4v_ldc_rx_set_qhead(lp->id, head);
329 if (!err)
330 return 0;
331
332 if (err != HV_EWOULDBLOCK)
333 return -EINVAL;
334
335 udelay(1);
336 }
337
338 return -EBUSY;
339 }
340
341 static int send_tx_packet(struct ldc_channel *lp,
342 struct ldc_packet *p,
343 unsigned long new_tail)
344 {
345 BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
346
347 return set_tx_tail(lp, new_tail);
348 }
349
350 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
351 u8 stype, u8 ctrl,
352 void *data, int dlen,
353 unsigned long *new_tail)
354 {
355 struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
356
357 if (p) {
358 memset(p, 0, sizeof(*p));
359 p->type = LDC_CTRL;
360 p->stype = stype;
361 p->ctrl = ctrl;
362 if (data)
363 memcpy(p->u.u_data, data, dlen);
364 }
365 return p;
366 }
367
368 static int start_handshake(struct ldc_channel *lp)
369 {
370 struct ldc_packet *p;
371 struct ldc_version *ver;
372 unsigned long new_tail;
373
374 ver = &ver_arr[0];
375
376 ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
377 ver->major, ver->minor);
378
379 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
380 ver, sizeof(*ver), &new_tail);
381 if (p) {
382 int err = send_tx_packet(lp, p, new_tail);
383 if (!err)
384 lp->flags &= ~LDC_FLAG_RESET;
385 return err;
386 }
387 return -EBUSY;
388 }
389
390 static int send_version_nack(struct ldc_channel *lp,
391 u16 major, u16 minor)
392 {
393 struct ldc_packet *p;
394 struct ldc_version ver;
395 unsigned long new_tail;
396
397 ver.major = major;
398 ver.minor = minor;
399
400 p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
401 &ver, sizeof(ver), &new_tail);
402 if (p) {
403 ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
404 ver.major, ver.minor);
405
406 return send_tx_packet(lp, p, new_tail);
407 }
408 return -EBUSY;
409 }
410
411 static int send_version_ack(struct ldc_channel *lp,
412 struct ldc_version *vp)
413 {
414 struct ldc_packet *p;
415 unsigned long new_tail;
416
417 p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
418 vp, sizeof(*vp), &new_tail);
419 if (p) {
420 ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
421 vp->major, vp->minor);
422
423 return send_tx_packet(lp, p, new_tail);
424 }
425 return -EBUSY;
426 }
427
428 static int send_rts(struct ldc_channel *lp)
429 {
430 struct ldc_packet *p;
431 unsigned long new_tail;
432
433 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
434 &new_tail);
435 if (p) {
436 p->env = lp->cfg.mode;
437 p->seqid = 0;
438 lp->rcv_nxt = 0;
439
440 ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
441 p->env, p->seqid);
442
443 return send_tx_packet(lp, p, new_tail);
444 }
445 return -EBUSY;
446 }
447
448 static int send_rtr(struct ldc_channel *lp)
449 {
450 struct ldc_packet *p;
451 unsigned long new_tail;
452
453 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
454 &new_tail);
455 if (p) {
456 p->env = lp->cfg.mode;
457 p->seqid = 0;
458
459 ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
460 p->env, p->seqid);
461
462 return send_tx_packet(lp, p, new_tail);
463 }
464 return -EBUSY;
465 }
466
467 static int send_rdx(struct ldc_channel *lp)
468 {
469 struct ldc_packet *p;
470 unsigned long new_tail;
471
472 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
473 &new_tail);
474 if (p) {
475 p->env = 0;
476 p->seqid = ++lp->snd_nxt;
477 p->u.r.ackid = lp->rcv_nxt;
478
479 ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
480 p->env, p->seqid, p->u.r.ackid);
481
482 return send_tx_packet(lp, p, new_tail);
483 }
484 return -EBUSY;
485 }
486
487 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
488 {
489 struct ldc_packet *p;
490 unsigned long new_tail;
491 int err;
492
493 p = data_get_tx_packet(lp, &new_tail);
494 if (!p)
495 return -EBUSY;
496 memset(p, 0, sizeof(*p));
497 p->type = data_pkt->type;
498 p->stype = LDC_NACK;
499 p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
500 p->seqid = lp->snd_nxt + 1;
501 p->u.r.ackid = lp->rcv_nxt;
502
503 ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
504 p->type, p->ctrl, p->seqid, p->u.r.ackid);
505
506 err = send_tx_packet(lp, p, new_tail);
507 if (!err)
508 lp->snd_nxt++;
509
510 return err;
511 }
512
513 static int ldc_abort(struct ldc_channel *lp)
514 {
515 unsigned long hv_err;
516
517 ldcdbg(STATE, "ABORT\n");
518
519 /* We report but do not act upon the hypervisor errors because
520 * there really isn't much we can do if they fail at this point.
521 */
522 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
523 if (hv_err)
524 printk(KERN_ERR PFX "ldc_abort: "
525 "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
526 lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
527
528 hv_err = sun4v_ldc_tx_get_state(lp->id,
529 &lp->tx_head,
530 &lp->tx_tail,
531 &lp->chan_state);
532 if (hv_err)
533 printk(KERN_ERR PFX "ldc_abort: "
534 "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
535 lp->id, hv_err);
536
537 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
538 if (hv_err)
539 printk(KERN_ERR PFX "ldc_abort: "
540 "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
541 lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
542
543 /* Refetch the RX queue state as well, because we could be invoked
544 * here in the queue processing context.
545 */
546 hv_err = sun4v_ldc_rx_get_state(lp->id,
547 &lp->rx_head,
548 &lp->rx_tail,
549 &lp->chan_state);
550 if (hv_err)
551 printk(KERN_ERR PFX "ldc_abort: "
552 "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
553 lp->id, hv_err);
554
555 return -ECONNRESET;
556 }
557
558 static struct ldc_version *find_by_major(u16 major)
559 {
560 struct ldc_version *ret = NULL;
561 int i;
562
563 for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
564 struct ldc_version *v = &ver_arr[i];
565 if (v->major <= major) {
566 ret = v;
567 break;
568 }
569 }
570 return ret;
571 }
572
573 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
574 {
575 struct ldc_version *vap;
576 int err;
577
578 ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
579 vp->major, vp->minor);
580
581 if (lp->hs_state == LDC_HS_GOTVERS) {
582 lp->hs_state = LDC_HS_OPEN;
583 memset(&lp->ver, 0, sizeof(lp->ver));
584 }
585
586 vap = find_by_major(vp->major);
587 if (!vap) {
588 err = send_version_nack(lp, 0, 0);
589 } else if (vap->major != vp->major) {
590 err = send_version_nack(lp, vap->major, vap->minor);
591 } else {
592 struct ldc_version ver = *vp;
593 if (ver.minor > vap->minor)
594 ver.minor = vap->minor;
595 err = send_version_ack(lp, &ver);
596 if (!err) {
597 lp->ver = ver;
598 lp->hs_state = LDC_HS_GOTVERS;
599 }
600 }
601 if (err)
602 return ldc_abort(lp);
603
604 return 0;
605 }
606
607 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
608 {
609 ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
610 vp->major, vp->minor);
611
612 if (lp->hs_state == LDC_HS_GOTVERS) {
613 if (lp->ver.major != vp->major ||
614 lp->ver.minor != vp->minor)
615 return ldc_abort(lp);
616 } else {
617 lp->ver = *vp;
618 lp->hs_state = LDC_HS_GOTVERS;
619 }
620 if (send_rts(lp))
621 return ldc_abort(lp);
622 return 0;
623 }
624
625 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
626 {
627 struct ldc_version *vap;
628 struct ldc_packet *p;
629 unsigned long new_tail;
630
631 if (vp->major == 0 && vp->minor == 0)
632 return ldc_abort(lp);
633
634 vap = find_by_major(vp->major);
635 if (!vap)
636 return ldc_abort(lp);
637
638 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
639 vap, sizeof(*vap),
640 &new_tail);
641 if (!p)
642 return ldc_abort(lp);
643
644 return send_tx_packet(lp, p, new_tail);
645 }
646
647 static int process_version(struct ldc_channel *lp,
648 struct ldc_packet *p)
649 {
650 struct ldc_version *vp;
651
652 vp = (struct ldc_version *) p->u.u_data;
653
654 switch (p->stype) {
655 case LDC_INFO:
656 return process_ver_info(lp, vp);
657
658 case LDC_ACK:
659 return process_ver_ack(lp, vp);
660
661 case LDC_NACK:
662 return process_ver_nack(lp, vp);
663
664 default:
665 return ldc_abort(lp);
666 }
667 }
668
669 static int process_rts(struct ldc_channel *lp,
670 struct ldc_packet *p)
671 {
672 ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
673 p->stype, p->seqid, p->env);
674
675 if (p->stype != LDC_INFO ||
676 lp->hs_state != LDC_HS_GOTVERS ||
677 p->env != lp->cfg.mode)
678 return ldc_abort(lp);
679
680 lp->snd_nxt = p->seqid;
681 lp->rcv_nxt = p->seqid;
682 lp->hs_state = LDC_HS_SENTRTR;
683 if (send_rtr(lp))
684 return ldc_abort(lp);
685
686 return 0;
687 }
688
689 static int process_rtr(struct ldc_channel *lp,
690 struct ldc_packet *p)
691 {
692 ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
693 p->stype, p->seqid, p->env);
694
695 if (p->stype != LDC_INFO ||
696 p->env != lp->cfg.mode)
697 return ldc_abort(lp);
698
699 lp->snd_nxt = p->seqid;
700 lp->hs_state = LDC_HS_COMPLETE;
701 ldc_set_state(lp, LDC_STATE_CONNECTED);
702 send_rdx(lp);
703
704 return LDC_EVENT_UP;
705 }
706
707 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
708 {
709 return lp->rcv_nxt + 1 == seqid;
710 }
711
712 static int process_rdx(struct ldc_channel *lp,
713 struct ldc_packet *p)
714 {
715 ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
716 p->stype, p->seqid, p->env, p->u.r.ackid);
717
718 if (p->stype != LDC_INFO ||
719 !(rx_seq_ok(lp, p->seqid)))
720 return ldc_abort(lp);
721
722 lp->rcv_nxt = p->seqid;
723
724 lp->hs_state = LDC_HS_COMPLETE;
725 ldc_set_state(lp, LDC_STATE_CONNECTED);
726
727 return LDC_EVENT_UP;
728 }
729
730 static int process_control_frame(struct ldc_channel *lp,
731 struct ldc_packet *p)
732 {
733 switch (p->ctrl) {
734 case LDC_VERS:
735 return process_version(lp, p);
736
737 case LDC_RTS:
738 return process_rts(lp, p);
739
740 case LDC_RTR:
741 return process_rtr(lp, p);
742
743 case LDC_RDX:
744 return process_rdx(lp, p);
745
746 default:
747 return ldc_abort(lp);
748 }
749 }
750
751 static int process_error_frame(struct ldc_channel *lp,
752 struct ldc_packet *p)
753 {
754 return ldc_abort(lp);
755 }
756
757 static int process_data_ack(struct ldc_channel *lp,
758 struct ldc_packet *ack)
759 {
760 unsigned long head = lp->tx_acked;
761 u32 ackid = ack->u.r.ackid;
762
763 while (1) {
764 struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
765
766 head = tx_advance(lp, head);
767
768 if (p->seqid == ackid) {
769 lp->tx_acked = head;
770 return 0;
771 }
772 if (head == lp->tx_tail)
773 return ldc_abort(lp);
774 }
775
776 return 0;
777 }
778
779 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
780 {
781 if (event_mask & LDC_EVENT_RESET)
782 lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
783 if (event_mask & LDC_EVENT_UP)
784 lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
785 if (event_mask & LDC_EVENT_DATA_READY)
786 lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
787 }
788
789 static irqreturn_t ldc_rx(int irq, void *dev_id)
790 {
791 struct ldc_channel *lp = dev_id;
792 unsigned long orig_state, hv_err, flags;
793 unsigned int event_mask;
794
795 spin_lock_irqsave(&lp->lock, flags);
796
797 orig_state = lp->chan_state;
798 hv_err = sun4v_ldc_rx_get_state(lp->id,
799 &lp->rx_head,
800 &lp->rx_tail,
801 &lp->chan_state);
802
803 ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
804 orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
805
806 event_mask = 0;
807
808 if (lp->cfg.mode == LDC_MODE_RAW &&
809 lp->chan_state == LDC_CHANNEL_UP) {
810 lp->hs_state = LDC_HS_COMPLETE;
811 ldc_set_state(lp, LDC_STATE_CONNECTED);
812
813 event_mask |= LDC_EVENT_UP;
814
815 orig_state = lp->chan_state;
816 }
817
818 /* If we are in reset state, flush the RX queue and ignore
819 * everything.
820 */
821 if (lp->flags & LDC_FLAG_RESET) {
822 (void) __set_rx_head(lp, lp->rx_tail);
823 goto out;
824 }
825
826 /* Once we finish the handshake, we let the ldc_read()
827 * paths do all of the control frame and state management.
828 * Just trigger the callback.
829 */
830 if (lp->hs_state == LDC_HS_COMPLETE) {
831 handshake_complete:
832 if (lp->chan_state != orig_state) {
833 unsigned int event = LDC_EVENT_RESET;
834
835 if (lp->chan_state == LDC_CHANNEL_UP)
836 event = LDC_EVENT_UP;
837
838 event_mask |= event;
839 }
840 if (lp->rx_head != lp->rx_tail)
841 event_mask |= LDC_EVENT_DATA_READY;
842
843 goto out;
844 }
845
846 if (lp->chan_state != orig_state)
847 goto out;
848
849 while (lp->rx_head != lp->rx_tail) {
850 struct ldc_packet *p;
851 unsigned long new;
852 int err;
853
854 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
855
856 switch (p->type) {
857 case LDC_CTRL:
858 err = process_control_frame(lp, p);
859 if (err > 0)
860 event_mask |= err;
861 break;
862
863 case LDC_DATA:
864 event_mask |= LDC_EVENT_DATA_READY;
865 err = 0;
866 break;
867
868 case LDC_ERR:
869 err = process_error_frame(lp, p);
870 break;
871
872 default:
873 err = ldc_abort(lp);
874 break;
875 }
876
877 if (err < 0)
878 break;
879
880 new = lp->rx_head;
881 new += LDC_PACKET_SIZE;
882 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
883 new = 0;
884 lp->rx_head = new;
885
886 err = __set_rx_head(lp, new);
887 if (err < 0) {
888 (void) ldc_abort(lp);
889 break;
890 }
891 if (lp->hs_state == LDC_HS_COMPLETE)
892 goto handshake_complete;
893 }
894
895 out:
896 spin_unlock_irqrestore(&lp->lock, flags);
897
898 send_events(lp, event_mask);
899
900 return IRQ_HANDLED;
901 }
902
903 static irqreturn_t ldc_tx(int irq, void *dev_id)
904 {
905 struct ldc_channel *lp = dev_id;
906 unsigned long flags, hv_err, orig_state;
907 unsigned int event_mask = 0;
908
909 spin_lock_irqsave(&lp->lock, flags);
910
911 orig_state = lp->chan_state;
912 hv_err = sun4v_ldc_tx_get_state(lp->id,
913 &lp->tx_head,
914 &lp->tx_tail,
915 &lp->chan_state);
916
917 ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
918 orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
919
920 if (lp->cfg.mode == LDC_MODE_RAW &&
921 lp->chan_state == LDC_CHANNEL_UP) {
922 lp->hs_state = LDC_HS_COMPLETE;
923 ldc_set_state(lp, LDC_STATE_CONNECTED);
924
925 event_mask |= LDC_EVENT_UP;
926 }
927
928 spin_unlock_irqrestore(&lp->lock, flags);
929
930 send_events(lp, event_mask);
931
932 return IRQ_HANDLED;
933 }
934
935 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
936 * XXX that addition and removal from the ldc_channel_list has
937 * XXX atomicity, otherwise the __ldc_channel_exists() check is
938 * XXX totally pointless as another thread can slip into ldc_alloc()
939 * XXX and add a channel with the same ID. There also needs to be
940 * XXX a spinlock for ldc_channel_list.
941 */
942 static HLIST_HEAD(ldc_channel_list);
943
944 static int __ldc_channel_exists(unsigned long id)
945 {
946 struct ldc_channel *lp;
947 struct hlist_node *n;
948
949 hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
950 if (lp->id == id)
951 return 1;
952 }
953 return 0;
954 }
955
956 static int alloc_queue(const char *name, unsigned long num_entries,
957 struct ldc_packet **base, unsigned long *ra)
958 {
959 unsigned long size, order;
960 void *q;
961
962 size = num_entries * LDC_PACKET_SIZE;
963 order = get_order(size);
964
965 q = (void *) __get_free_pages(GFP_KERNEL, order);
966 if (!q) {
967 printk(KERN_ERR PFX "Alloc of %s queue failed with "
968 "size=%lu order=%lu\n", name, size, order);
969 return -ENOMEM;
970 }
971
972 memset(q, 0, PAGE_SIZE << order);
973
974 *base = q;
975 *ra = __pa(q);
976
977 return 0;
978 }
979
980 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
981 {
982 unsigned long size, order;
983
984 if (!q)
985 return;
986
987 size = num_entries * LDC_PACKET_SIZE;
988 order = get_order(size);
989
990 free_pages((unsigned long)q, order);
991 }
992
993 /* XXX Make this configurable... XXX */
994 #define LDC_IOTABLE_SIZE (8 * 1024)
995
996 static int ldc_iommu_init(struct ldc_channel *lp)
997 {
998 unsigned long sz, num_tsb_entries, tsbsize, order;
999 struct ldc_iommu *iommu = &lp->iommu;
1000 struct ldc_mtable_entry *table;
1001 unsigned long hv_err;
1002 int err;
1003
1004 num_tsb_entries = LDC_IOTABLE_SIZE;
1005 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1006
1007 spin_lock_init(&iommu->lock);
1008
1009 sz = num_tsb_entries / 8;
1010 sz = (sz + 7UL) & ~7UL;
1011 iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1012 if (!iommu->arena.map) {
1013 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1014 return -ENOMEM;
1015 }
1016
1017 iommu->arena.limit = num_tsb_entries;
1018
1019 order = get_order(tsbsize);
1020
1021 table = (struct ldc_mtable_entry *)
1022 __get_free_pages(GFP_KERNEL, order);
1023 err = -ENOMEM;
1024 if (!table) {
1025 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1026 "size=%lu order=%lu\n", tsbsize, order);
1027 goto out_free_map;
1028 }
1029
1030 memset(table, 0, PAGE_SIZE << order);
1031
1032 iommu->page_table = table;
1033
1034 hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1035 num_tsb_entries);
1036 err = -EINVAL;
1037 if (hv_err)
1038 goto out_free_table;
1039
1040 return 0;
1041
1042 out_free_table:
1043 free_pages((unsigned long) table, order);
1044 iommu->page_table = NULL;
1045
1046 out_free_map:
1047 kfree(iommu->arena.map);
1048 iommu->arena.map = NULL;
1049
1050 return err;
1051 }
1052
1053 static void ldc_iommu_release(struct ldc_channel *lp)
1054 {
1055 struct ldc_iommu *iommu = &lp->iommu;
1056 unsigned long num_tsb_entries, tsbsize, order;
1057
1058 (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1059
1060 num_tsb_entries = iommu->arena.limit;
1061 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1062 order = get_order(tsbsize);
1063
1064 free_pages((unsigned long) iommu->page_table, order);
1065 iommu->page_table = NULL;
1066
1067 kfree(iommu->arena.map);
1068 iommu->arena.map = NULL;
1069 }
1070
1071 struct ldc_channel *ldc_alloc(unsigned long id,
1072 const struct ldc_channel_config *cfgp,
1073 void *event_arg)
1074 {
1075 struct ldc_channel *lp;
1076 const struct ldc_mode_ops *mops;
1077 unsigned long dummy1, dummy2, hv_err;
1078 u8 mss, *mssbuf;
1079 int err;
1080
1081 err = -ENODEV;
1082 if (!ldom_domaining_enabled)
1083 goto out_err;
1084
1085 err = -EINVAL;
1086 if (!cfgp)
1087 goto out_err;
1088
1089 switch (cfgp->mode) {
1090 case LDC_MODE_RAW:
1091 mops = &raw_ops;
1092 mss = LDC_PACKET_SIZE;
1093 break;
1094
1095 case LDC_MODE_UNRELIABLE:
1096 mops = &nonraw_ops;
1097 mss = LDC_PACKET_SIZE - 8;
1098 break;
1099
1100 case LDC_MODE_STREAM:
1101 mops = &stream_ops;
1102 mss = LDC_PACKET_SIZE - 8 - 8;
1103 break;
1104
1105 default:
1106 goto out_err;
1107 }
1108
1109 if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1110 goto out_err;
1111
1112 hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1113 err = -ENODEV;
1114 if (hv_err == HV_ECHANNEL)
1115 goto out_err;
1116
1117 err = -EEXIST;
1118 if (__ldc_channel_exists(id))
1119 goto out_err;
1120
1121 mssbuf = NULL;
1122
1123 lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1124 err = -ENOMEM;
1125 if (!lp)
1126 goto out_err;
1127
1128 spin_lock_init(&lp->lock);
1129
1130 lp->id = id;
1131
1132 err = ldc_iommu_init(lp);
1133 if (err)
1134 goto out_free_ldc;
1135
1136 lp->mops = mops;
1137 lp->mss = mss;
1138
1139 lp->cfg = *cfgp;
1140 if (!lp->cfg.mtu)
1141 lp->cfg.mtu = LDC_DEFAULT_MTU;
1142
1143 if (lp->cfg.mode == LDC_MODE_STREAM) {
1144 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1145 if (!mssbuf) {
1146 err = -ENOMEM;
1147 goto out_free_iommu;
1148 }
1149 lp->mssbuf = mssbuf;
1150 }
1151
1152 lp->event_arg = event_arg;
1153
1154 /* XXX allow setting via ldc_channel_config to override defaults
1155 * XXX or use some formula based upon mtu
1156 */
1157 lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1158 lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1159
1160 err = alloc_queue("TX", lp->tx_num_entries,
1161 &lp->tx_base, &lp->tx_ra);
1162 if (err)
1163 goto out_free_mssbuf;
1164
1165 err = alloc_queue("RX", lp->rx_num_entries,
1166 &lp->rx_base, &lp->rx_ra);
1167 if (err)
1168 goto out_free_txq;
1169
1170 lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1171
1172 lp->hs_state = LDC_HS_CLOSED;
1173 ldc_set_state(lp, LDC_STATE_INIT);
1174
1175 INIT_HLIST_NODE(&lp->list);
1176 hlist_add_head(&lp->list, &ldc_channel_list);
1177
1178 INIT_HLIST_HEAD(&lp->mh_list);
1179
1180 return lp;
1181
1182 out_free_txq:
1183 free_queue(lp->tx_num_entries, lp->tx_base);
1184
1185 out_free_mssbuf:
1186 kfree(mssbuf);
1187
1188 out_free_iommu:
1189 ldc_iommu_release(lp);
1190
1191 out_free_ldc:
1192 kfree(lp);
1193
1194 out_err:
1195 return ERR_PTR(err);
1196 }
1197 EXPORT_SYMBOL(ldc_alloc);
1198
1199 void ldc_free(struct ldc_channel *lp)
1200 {
1201 if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1202 free_irq(lp->cfg.rx_irq, lp);
1203 free_irq(lp->cfg.tx_irq, lp);
1204 }
1205
1206 if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1207 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1208 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1209 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1210 }
1211 if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1212 free_queue(lp->tx_num_entries, lp->tx_base);
1213 free_queue(lp->rx_num_entries, lp->rx_base);
1214 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1215 }
1216
1217 hlist_del(&lp->list);
1218
1219 kfree(lp->mssbuf);
1220
1221 ldc_iommu_release(lp);
1222
1223 kfree(lp);
1224 }
1225 EXPORT_SYMBOL(ldc_free);
1226
1227 /* Bind the channel. This registers the LDC queues with
1228 * the hypervisor and puts the channel into a pseudo-listening
1229 * state. This does not initiate a handshake, ldc_connect() does
1230 * that.
1231 */
1232 int ldc_bind(struct ldc_channel *lp, const char *name)
1233 {
1234 unsigned long hv_err, flags;
1235 int err = -EINVAL;
1236
1237 if (!name ||
1238 (lp->state != LDC_STATE_INIT))
1239 return -EINVAL;
1240
1241 snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1242 snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1243
1244 err = request_irq(lp->cfg.rx_irq, ldc_rx,
1245 IRQF_SAMPLE_RANDOM | IRQF_DISABLED | IRQF_SHARED,
1246 lp->rx_irq_name, lp);
1247 if (err)
1248 return err;
1249
1250 err = request_irq(lp->cfg.tx_irq, ldc_tx,
1251 IRQF_SAMPLE_RANDOM | IRQF_DISABLED | IRQF_SHARED,
1252 lp->tx_irq_name, lp);
1253 if (err) {
1254 free_irq(lp->cfg.rx_irq, lp);
1255 return err;
1256 }
1257
1258
1259 spin_lock_irqsave(&lp->lock, flags);
1260
1261 enable_irq(lp->cfg.rx_irq);
1262 enable_irq(lp->cfg.tx_irq);
1263
1264 lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1265
1266 err = -ENODEV;
1267 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1268 if (hv_err)
1269 goto out_free_irqs;
1270
1271 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1272 if (hv_err)
1273 goto out_free_irqs;
1274
1275 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1276 if (hv_err)
1277 goto out_unmap_tx;
1278
1279 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1280 if (hv_err)
1281 goto out_unmap_tx;
1282
1283 lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1284
1285 hv_err = sun4v_ldc_tx_get_state(lp->id,
1286 &lp->tx_head,
1287 &lp->tx_tail,
1288 &lp->chan_state);
1289 err = -EBUSY;
1290 if (hv_err)
1291 goto out_unmap_rx;
1292
1293 lp->tx_acked = lp->tx_head;
1294
1295 lp->hs_state = LDC_HS_OPEN;
1296 ldc_set_state(lp, LDC_STATE_BOUND);
1297
1298 spin_unlock_irqrestore(&lp->lock, flags);
1299
1300 return 0;
1301
1302 out_unmap_rx:
1303 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1304 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1305
1306 out_unmap_tx:
1307 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1308
1309 out_free_irqs:
1310 lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1311 free_irq(lp->cfg.tx_irq, lp);
1312 free_irq(lp->cfg.rx_irq, lp);
1313
1314 spin_unlock_irqrestore(&lp->lock, flags);
1315
1316 return err;
1317 }
1318 EXPORT_SYMBOL(ldc_bind);
1319
1320 int ldc_connect(struct ldc_channel *lp)
1321 {
1322 unsigned long flags;
1323 int err;
1324
1325 if (lp->cfg.mode == LDC_MODE_RAW)
1326 return -EINVAL;
1327
1328 spin_lock_irqsave(&lp->lock, flags);
1329
1330 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1331 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1332 lp->hs_state != LDC_HS_OPEN)
1333 err = -EINVAL;
1334 else
1335 err = start_handshake(lp);
1336
1337 spin_unlock_irqrestore(&lp->lock, flags);
1338
1339 return err;
1340 }
1341 EXPORT_SYMBOL(ldc_connect);
1342
1343 int ldc_disconnect(struct ldc_channel *lp)
1344 {
1345 unsigned long hv_err, flags;
1346 int err;
1347
1348 if (lp->cfg.mode == LDC_MODE_RAW)
1349 return -EINVAL;
1350
1351 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1352 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1353 return -EINVAL;
1354
1355 spin_lock_irqsave(&lp->lock, flags);
1356
1357 err = -ENODEV;
1358 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1359 if (hv_err)
1360 goto out_err;
1361
1362 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1363 if (hv_err)
1364 goto out_err;
1365
1366 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1367 if (hv_err)
1368 goto out_err;
1369
1370 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1371 if (hv_err)
1372 goto out_err;
1373
1374 ldc_set_state(lp, LDC_STATE_BOUND);
1375 lp->hs_state = LDC_HS_OPEN;
1376 lp->flags |= LDC_FLAG_RESET;
1377
1378 spin_unlock_irqrestore(&lp->lock, flags);
1379
1380 return 0;
1381
1382 out_err:
1383 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1384 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1385 free_irq(lp->cfg.tx_irq, lp);
1386 free_irq(lp->cfg.rx_irq, lp);
1387 lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1388 LDC_FLAG_REGISTERED_QUEUES);
1389 ldc_set_state(lp, LDC_STATE_INIT);
1390
1391 spin_unlock_irqrestore(&lp->lock, flags);
1392
1393 return err;
1394 }
1395 EXPORT_SYMBOL(ldc_disconnect);
1396
1397 int ldc_state(struct ldc_channel *lp)
1398 {
1399 return lp->state;
1400 }
1401 EXPORT_SYMBOL(ldc_state);
1402
1403 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1404 {
1405 struct ldc_packet *p;
1406 unsigned long new_tail;
1407 int err;
1408
1409 if (size > LDC_PACKET_SIZE)
1410 return -EMSGSIZE;
1411
1412 p = data_get_tx_packet(lp, &new_tail);
1413 if (!p)
1414 return -EAGAIN;
1415
1416 memcpy(p, buf, size);
1417
1418 err = send_tx_packet(lp, p, new_tail);
1419 if (!err)
1420 err = size;
1421
1422 return err;
1423 }
1424
1425 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1426 {
1427 struct ldc_packet *p;
1428 unsigned long hv_err, new;
1429 int err;
1430
1431 if (size < LDC_PACKET_SIZE)
1432 return -EINVAL;
1433
1434 hv_err = sun4v_ldc_rx_get_state(lp->id,
1435 &lp->rx_head,
1436 &lp->rx_tail,
1437 &lp->chan_state);
1438 if (hv_err)
1439 return ldc_abort(lp);
1440
1441 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1442 lp->chan_state == LDC_CHANNEL_RESETTING)
1443 return -ECONNRESET;
1444
1445 if (lp->rx_head == lp->rx_tail)
1446 return 0;
1447
1448 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1449 memcpy(buf, p, LDC_PACKET_SIZE);
1450
1451 new = rx_advance(lp, lp->rx_head);
1452 lp->rx_head = new;
1453
1454 err = __set_rx_head(lp, new);
1455 if (err < 0)
1456 err = -ECONNRESET;
1457 else
1458 err = LDC_PACKET_SIZE;
1459
1460 return err;
1461 }
1462
1463 static const struct ldc_mode_ops raw_ops = {
1464 .write = write_raw,
1465 .read = read_raw,
1466 };
1467
1468 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1469 unsigned int size)
1470 {
1471 unsigned long hv_err, tail;
1472 unsigned int copied;
1473 u32 seq;
1474 int err;
1475
1476 hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1477 &lp->chan_state);
1478 if (unlikely(hv_err))
1479 return -EBUSY;
1480
1481 if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1482 return ldc_abort(lp);
1483
1484 if (!tx_has_space_for(lp, size))
1485 return -EAGAIN;
1486
1487 seq = lp->snd_nxt;
1488 copied = 0;
1489 tail = lp->tx_tail;
1490 while (copied < size) {
1491 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1492 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1493 p->u.u_data :
1494 p->u.r.r_data);
1495 int data_len;
1496
1497 p->type = LDC_DATA;
1498 p->stype = LDC_INFO;
1499 p->ctrl = 0;
1500
1501 data_len = size - copied;
1502 if (data_len > lp->mss)
1503 data_len = lp->mss;
1504
1505 BUG_ON(data_len > LDC_LEN);
1506
1507 p->env = (data_len |
1508 (copied == 0 ? LDC_START : 0) |
1509 (data_len == size - copied ? LDC_STOP : 0));
1510
1511 p->seqid = ++seq;
1512
1513 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1514 p->type,
1515 p->stype,
1516 p->ctrl,
1517 p->env,
1518 p->seqid);
1519
1520 memcpy(data, buf, data_len);
1521 buf += data_len;
1522 copied += data_len;
1523
1524 tail = tx_advance(lp, tail);
1525 }
1526
1527 err = set_tx_tail(lp, tail);
1528 if (!err) {
1529 lp->snd_nxt = seq;
1530 err = size;
1531 }
1532
1533 return err;
1534 }
1535
1536 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1537 struct ldc_packet *first_frag)
1538 {
1539 int err;
1540
1541 if (first_frag)
1542 lp->rcv_nxt = first_frag->seqid - 1;
1543
1544 err = send_data_nack(lp, p);
1545 if (err)
1546 return err;
1547
1548 err = __set_rx_head(lp, lp->rx_tail);
1549 if (err < 0)
1550 return ldc_abort(lp);
1551
1552 return 0;
1553 }
1554
1555 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1556 {
1557 if (p->stype & LDC_ACK) {
1558 int err = process_data_ack(lp, p);
1559 if (err)
1560 return err;
1561 }
1562 if (p->stype & LDC_NACK)
1563 return ldc_abort(lp);
1564
1565 return 0;
1566 }
1567
1568 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1569 {
1570 unsigned long dummy;
1571 int limit = 1000;
1572
1573 ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1574 cur_head, lp->rx_head, lp->rx_tail);
1575 while (limit-- > 0) {
1576 unsigned long hv_err;
1577
1578 hv_err = sun4v_ldc_rx_get_state(lp->id,
1579 &dummy,
1580 &lp->rx_tail,
1581 &lp->chan_state);
1582 if (hv_err)
1583 return ldc_abort(lp);
1584
1585 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1586 lp->chan_state == LDC_CHANNEL_RESETTING)
1587 return -ECONNRESET;
1588
1589 if (cur_head != lp->rx_tail) {
1590 ldcdbg(DATA, "DATA WAIT DONE "
1591 "head[%lx] tail[%lx] chan_state[%lx]\n",
1592 dummy, lp->rx_tail, lp->chan_state);
1593 return 0;
1594 }
1595
1596 udelay(1);
1597 }
1598 return -EAGAIN;
1599 }
1600
1601 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1602 {
1603 int err = __set_rx_head(lp, head);
1604
1605 if (err < 0)
1606 return ldc_abort(lp);
1607
1608 lp->rx_head = head;
1609 return 0;
1610 }
1611
1612 static void send_data_ack(struct ldc_channel *lp)
1613 {
1614 unsigned long new_tail;
1615 struct ldc_packet *p;
1616
1617 p = data_get_tx_packet(lp, &new_tail);
1618 if (likely(p)) {
1619 int err;
1620
1621 memset(p, 0, sizeof(*p));
1622 p->type = LDC_DATA;
1623 p->stype = LDC_ACK;
1624 p->ctrl = 0;
1625 p->seqid = lp->snd_nxt + 1;
1626 p->u.r.ackid = lp->rcv_nxt;
1627
1628 err = send_tx_packet(lp, p, new_tail);
1629 if (!err)
1630 lp->snd_nxt++;
1631 }
1632 }
1633
1634 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1635 {
1636 struct ldc_packet *first_frag;
1637 unsigned long hv_err, new;
1638 int err, copied;
1639
1640 hv_err = sun4v_ldc_rx_get_state(lp->id,
1641 &lp->rx_head,
1642 &lp->rx_tail,
1643 &lp->chan_state);
1644 if (hv_err)
1645 return ldc_abort(lp);
1646
1647 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1648 lp->chan_state == LDC_CHANNEL_RESETTING)
1649 return -ECONNRESET;
1650
1651 if (lp->rx_head == lp->rx_tail)
1652 return 0;
1653
1654 first_frag = NULL;
1655 copied = err = 0;
1656 new = lp->rx_head;
1657 while (1) {
1658 struct ldc_packet *p;
1659 int pkt_len;
1660
1661 BUG_ON(new == lp->rx_tail);
1662 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1663
1664 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1665 "rcv_nxt[%08x]\n",
1666 p->type,
1667 p->stype,
1668 p->ctrl,
1669 p->env,
1670 p->seqid,
1671 p->u.r.ackid,
1672 lp->rcv_nxt);
1673
1674 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1675 err = rx_bad_seq(lp, p, first_frag);
1676 copied = 0;
1677 break;
1678 }
1679
1680 if (p->type & LDC_CTRL) {
1681 err = process_control_frame(lp, p);
1682 if (err < 0)
1683 break;
1684 err = 0;
1685 }
1686
1687 lp->rcv_nxt = p->seqid;
1688
1689 if (!(p->type & LDC_DATA)) {
1690 new = rx_advance(lp, new);
1691 goto no_data;
1692 }
1693 if (p->stype & (LDC_ACK | LDC_NACK)) {
1694 err = data_ack_nack(lp, p);
1695 if (err)
1696 break;
1697 }
1698 if (!(p->stype & LDC_INFO)) {
1699 new = rx_advance(lp, new);
1700 err = rx_set_head(lp, new);
1701 if (err)
1702 break;
1703 goto no_data;
1704 }
1705
1706 pkt_len = p->env & LDC_LEN;
1707
1708 /* Every initial packet starts with the START bit set.
1709 *
1710 * Singleton packets will have both START+STOP set.
1711 *
1712 * Fragments will have START set in the first frame, STOP
1713 * set in the last frame, and neither bit set in middle
1714 * frames of the packet.
1715 *
1716 * Therefore if we are at the beginning of a packet and
1717 * we don't see START, or we are in the middle of a fragmented
1718 * packet and do see START, we are unsynchronized and should
1719 * flush the RX queue.
1720 */
1721 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1722 (first_frag != NULL && (p->env & LDC_START))) {
1723 if (!first_frag)
1724 new = rx_advance(lp, new);
1725
1726 err = rx_set_head(lp, new);
1727 if (err)
1728 break;
1729
1730 if (!first_frag)
1731 goto no_data;
1732 }
1733 if (!first_frag)
1734 first_frag = p;
1735
1736 if (pkt_len > size - copied) {
1737 /* User didn't give us a big enough buffer,
1738 * what to do? This is a pretty serious error.
1739 *
1740 * Since we haven't updated the RX ring head to
1741 * consume any of the packets, signal the error
1742 * to the user and just leave the RX ring alone.
1743 *
1744 * This seems the best behavior because this allows
1745 * a user of the LDC layer to start with a small
1746 * RX buffer for ldc_read() calls and use -EMSGSIZE
1747 * as a cue to enlarge it's read buffer.
1748 */
1749 err = -EMSGSIZE;
1750 break;
1751 }
1752
1753 /* Ok, we are gonna eat this one. */
1754 new = rx_advance(lp, new);
1755
1756 memcpy(buf,
1757 (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1758 p->u.u_data : p->u.r.r_data), pkt_len);
1759 buf += pkt_len;
1760 copied += pkt_len;
1761
1762 if (p->env & LDC_STOP)
1763 break;
1764
1765 no_data:
1766 if (new == lp->rx_tail) {
1767 err = rx_data_wait(lp, new);
1768 if (err)
1769 break;
1770 }
1771 }
1772
1773 if (!err)
1774 err = rx_set_head(lp, new);
1775
1776 if (err && first_frag)
1777 lp->rcv_nxt = first_frag->seqid - 1;
1778
1779 if (!err) {
1780 err = copied;
1781 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1782 send_data_ack(lp);
1783 }
1784
1785 return err;
1786 }
1787
1788 static const struct ldc_mode_ops nonraw_ops = {
1789 .write = write_nonraw,
1790 .read = read_nonraw,
1791 };
1792
1793 static int write_stream(struct ldc_channel *lp, const void *buf,
1794 unsigned int size)
1795 {
1796 if (size > lp->cfg.mtu)
1797 size = lp->cfg.mtu;
1798 return write_nonraw(lp, buf, size);
1799 }
1800
1801 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1802 {
1803 if (!lp->mssbuf_len) {
1804 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1805 if (err < 0)
1806 return err;
1807
1808 lp->mssbuf_len = err;
1809 lp->mssbuf_off = 0;
1810 }
1811
1812 if (size > lp->mssbuf_len)
1813 size = lp->mssbuf_len;
1814 memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1815
1816 lp->mssbuf_off += size;
1817 lp->mssbuf_len -= size;
1818
1819 return size;
1820 }
1821
1822 static const struct ldc_mode_ops stream_ops = {
1823 .write = write_stream,
1824 .read = read_stream,
1825 };
1826
1827 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1828 {
1829 unsigned long flags;
1830 int err;
1831
1832 if (!buf)
1833 return -EINVAL;
1834
1835 if (!size)
1836 return 0;
1837
1838 spin_lock_irqsave(&lp->lock, flags);
1839
1840 if (lp->hs_state != LDC_HS_COMPLETE)
1841 err = -ENOTCONN;
1842 else
1843 err = lp->mops->write(lp, buf, size);
1844
1845 spin_unlock_irqrestore(&lp->lock, flags);
1846
1847 return err;
1848 }
1849 EXPORT_SYMBOL(ldc_write);
1850
1851 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1852 {
1853 unsigned long flags;
1854 int err;
1855
1856 if (!buf)
1857 return -EINVAL;
1858
1859 if (!size)
1860 return 0;
1861
1862 spin_lock_irqsave(&lp->lock, flags);
1863
1864 if (lp->hs_state != LDC_HS_COMPLETE)
1865 err = -ENOTCONN;
1866 else
1867 err = lp->mops->read(lp, buf, size);
1868
1869 spin_unlock_irqrestore(&lp->lock, flags);
1870
1871 return err;
1872 }
1873 EXPORT_SYMBOL(ldc_read);
1874
1875 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1876 {
1877 struct iommu_arena *arena = &iommu->arena;
1878 unsigned long n, i, start, end, limit;
1879 int pass;
1880
1881 limit = arena->limit;
1882 start = arena->hint;
1883 pass = 0;
1884
1885 again:
1886 n = find_next_zero_bit(arena->map, limit, start);
1887 end = n + npages;
1888 if (unlikely(end >= limit)) {
1889 if (likely(pass < 1)) {
1890 limit = start;
1891 start = 0;
1892 pass++;
1893 goto again;
1894 } else {
1895 /* Scanned the whole thing, give up. */
1896 return -1;
1897 }
1898 }
1899
1900 for (i = n; i < end; i++) {
1901 if (test_bit(i, arena->map)) {
1902 start = i + 1;
1903 goto again;
1904 }
1905 }
1906
1907 for (i = n; i < end; i++)
1908 __set_bit(i, arena->map);
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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