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sparc32: Fix exit flag passed from traced sys_sigreturn
[linux-2.6/btrfs-unstable.git] / arch / sparc / kernel / ldc.c
blob54df554b82d98a684a3cbd7710ea10998e0d1722
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/export.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[] =
31 DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
32 #define LDC_PACKET_SIZE 64
33
34 /* Packet header layout for unreliable and reliable mode frames.
35 * When in RAW mode, packets are simply straight 64-byte payloads
36 * with no headers.
37 */
38 struct ldc_packet {
39 u8 type;
40 #define LDC_CTRL 0x01
41 #define LDC_DATA 0x02
42 #define LDC_ERR 0x10
43
44 u8 stype;
45 #define LDC_INFO 0x01
46 #define LDC_ACK 0x02
47 #define LDC_NACK 0x04
48
49 u8 ctrl;
50 #define LDC_VERS 0x01 /* Link Version */
51 #define LDC_RTS 0x02 /* Request To Send */
52 #define LDC_RTR 0x03 /* Ready To Receive */
53 #define LDC_RDX 0x04 /* Ready for Data eXchange */
54 #define LDC_CTRL_MSK 0x0f
55
56 u8 env;
57 #define LDC_LEN 0x3f
58 #define LDC_FRAG_MASK 0xc0
59 #define LDC_START 0x40
60 #define LDC_STOP 0x80
61
62 u32 seqid;
63
64 union {
65 u8 u_data[LDC_PACKET_SIZE - 8];
66 struct {
67 u32 pad;
68 u32 ackid;
69 u8 r_data[LDC_PACKET_SIZE - 8 - 8];
70 } r;
71 } u;
72 };
73
74 struct ldc_version {
75 u16 major;
76 u16 minor;
77 };
78
79 /* Ordered from largest major to lowest. */
80 static struct ldc_version ver_arr[] = {
81 { .major = 1, .minor = 0 },
82 };
83
84 #define LDC_DEFAULT_MTU (4 * LDC_PACKET_SIZE)
85 #define LDC_DEFAULT_NUM_ENTRIES (PAGE_SIZE / LDC_PACKET_SIZE)
86
87 struct ldc_channel;
88
89 struct ldc_mode_ops {
90 int (*write)(struct ldc_channel *, const void *, unsigned int);
91 int (*read)(struct ldc_channel *, void *, unsigned int);
92 };
93
94 static const struct ldc_mode_ops raw_ops;
95 static const struct ldc_mode_ops nonraw_ops;
96 static const struct ldc_mode_ops stream_ops;
97
98 int ldom_domaining_enabled;
99
100 struct ldc_iommu {
101 /* Protects arena alloc/free. */
102 spinlock_t lock;
103 struct iommu_arena arena;
104 struct ldc_mtable_entry *page_table;
105 };
106
107 struct ldc_channel {
108 /* Protects all operations that depend upon channel state. */
109 spinlock_t lock;
110
111 unsigned long id;
112
113 u8 *mssbuf;
114 u32 mssbuf_len;
115 u32 mssbuf_off;
116
117 struct ldc_packet *tx_base;
118 unsigned long tx_head;
119 unsigned long tx_tail;
120 unsigned long tx_num_entries;
121 unsigned long tx_ra;
122
123 unsigned long tx_acked;
124
125 struct ldc_packet *rx_base;
126 unsigned long rx_head;
127 unsigned long rx_tail;
128 unsigned long rx_num_entries;
129 unsigned long rx_ra;
130
131 u32 rcv_nxt;
132 u32 snd_nxt;
133
134 unsigned long chan_state;
135
136 struct ldc_channel_config cfg;
137 void *event_arg;
138
139 const struct ldc_mode_ops *mops;
140
141 struct ldc_iommu iommu;
142
143 struct ldc_version ver;
144
145 u8 hs_state;
146 #define LDC_HS_CLOSED 0x00
147 #define LDC_HS_OPEN 0x01
148 #define LDC_HS_GOTVERS 0x02
149 #define LDC_HS_SENTRTR 0x03
150 #define LDC_HS_GOTRTR 0x04
151 #define LDC_HS_COMPLETE 0x10
152
153 u8 flags;
154 #define LDC_FLAG_ALLOCED_QUEUES 0x01
155 #define LDC_FLAG_REGISTERED_QUEUES 0x02
156 #define LDC_FLAG_REGISTERED_IRQS 0x04
157 #define LDC_FLAG_RESET 0x10
158
159 u8 mss;
160 u8 state;
161
162 #define LDC_IRQ_NAME_MAX 32
163 char rx_irq_name[LDC_IRQ_NAME_MAX];
164 char tx_irq_name[LDC_IRQ_NAME_MAX];
165
166 struct hlist_head mh_list;
167
168 struct hlist_node list;
169 };
170
171 #define ldcdbg(TYPE, f, a...) \
172 do { if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
173 printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
174 } while (0)
175
176 static const char *state_to_str(u8 state)
177 {
178 switch (state) {
179 case LDC_STATE_INVALID:
180 return "INVALID";
181 case LDC_STATE_INIT:
182 return "INIT";
183 case LDC_STATE_BOUND:
184 return "BOUND";
185 case LDC_STATE_READY:
186 return "READY";
187 case LDC_STATE_CONNECTED:
188 return "CONNECTED";
189 default:
190 return "<UNKNOWN>";
191 }
192 }
193
194 static void ldc_set_state(struct ldc_channel *lp, u8 state)
195 {
196 ldcdbg(STATE, "STATE (%s) --> (%s)\n",
197 state_to_str(lp->state),
198 state_to_str(state));
199
200 lp->state = state;
201 }
202
203 static unsigned long __advance(unsigned long off, unsigned long num_entries)
204 {
205 off += LDC_PACKET_SIZE;
206 if (off == (num_entries * LDC_PACKET_SIZE))
207 off = 0;
208
209 return off;
210 }
211
212 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
213 {
214 return __advance(off, lp->rx_num_entries);
215 }
216
217 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
218 {
219 return __advance(off, lp->tx_num_entries);
220 }
221
222 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
223 unsigned long *new_tail)
224 {
225 struct ldc_packet *p;
226 unsigned long t;
227
228 t = tx_advance(lp, lp->tx_tail);
229 if (t == lp->tx_head)
230 return NULL;
231
232 *new_tail = t;
233
234 p = lp->tx_base;
235 return p + (lp->tx_tail / LDC_PACKET_SIZE);
236 }
237
238 /* When we are in reliable or stream mode, have to track the next packet
239 * we haven't gotten an ACK for in the TX queue using tx_acked. We have
240 * to be careful not to stomp over the queue past that point. During
241 * the handshake, we don't have TX data packets pending in the queue
242 * and that's why handshake_get_tx_packet() need not be mindful of
243 * lp->tx_acked.
244 */
245 static unsigned long head_for_data(struct ldc_channel *lp)
246 {
247 if (lp->cfg.mode == LDC_MODE_STREAM)
248 return lp->tx_acked;
249 return lp->tx_head;
250 }
251
252 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
253 {
254 unsigned long limit, tail, new_tail, diff;
255 unsigned int mss;
256
257 limit = head_for_data(lp);
258 tail = lp->tx_tail;
259 new_tail = tx_advance(lp, tail);
260 if (new_tail == limit)
261 return 0;
262
263 if (limit > new_tail)
264 diff = limit - new_tail;
265 else
266 diff = (limit +
267 ((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
268 diff /= LDC_PACKET_SIZE;
269 mss = lp->mss;
270
271 if (diff * mss < size)
272 return 0;
273
274 return 1;
275 }
276
277 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
278 unsigned long *new_tail)
279 {
280 struct ldc_packet *p;
281 unsigned long h, t;
282
283 h = head_for_data(lp);
284 t = tx_advance(lp, lp->tx_tail);
285 if (t == h)
286 return NULL;
287
288 *new_tail = t;
289
290 p = lp->tx_base;
291 return p + (lp->tx_tail / LDC_PACKET_SIZE);
292 }
293
294 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
295 {
296 unsigned long orig_tail = lp->tx_tail;
297 int limit = 1000;
298
299 lp->tx_tail = tail;
300 while (limit-- > 0) {
301 unsigned long err;
302
303 err = sun4v_ldc_tx_set_qtail(lp->id, tail);
304 if (!err)
305 return 0;
306
307 if (err != HV_EWOULDBLOCK) {
308 lp->tx_tail = orig_tail;
309 return -EINVAL;
310 }
311 udelay(1);
312 }
313
314 lp->tx_tail = orig_tail;
315 return -EBUSY;
316 }
317
318 /* This just updates the head value in the hypervisor using
319 * a polling loop with a timeout. The caller takes care of
320 * upating software state representing the head change, if any.
321 */
322 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
323 {
324 int limit = 1000;
325
326 while (limit-- > 0) {
327 unsigned long err;
328
329 err = sun4v_ldc_rx_set_qhead(lp->id, head);
330 if (!err)
331 return 0;
332
333 if (err != HV_EWOULDBLOCK)
334 return -EINVAL;
335
336 udelay(1);
337 }
338
339 return -EBUSY;
340 }
341
342 static int send_tx_packet(struct ldc_channel *lp,
343 struct ldc_packet *p,
344 unsigned long new_tail)
345 {
346 BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
347
348 return set_tx_tail(lp, new_tail);
349 }
350
351 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
352 u8 stype, u8 ctrl,
353 void *data, int dlen,
354 unsigned long *new_tail)
355 {
356 struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
357
358 if (p) {
359 memset(p, 0, sizeof(*p));
360 p->type = LDC_CTRL;
361 p->stype = stype;
362 p->ctrl = ctrl;
363 if (data)
364 memcpy(p->u.u_data, data, dlen);
365 }
366 return p;
367 }
368
369 static int start_handshake(struct ldc_channel *lp)
370 {
371 struct ldc_packet *p;
372 struct ldc_version *ver;
373 unsigned long new_tail;
374
375 ver = &ver_arr[0];
376
377 ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
378 ver->major, ver->minor);
379
380 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
381 ver, sizeof(*ver), &new_tail);
382 if (p) {
383 int err = send_tx_packet(lp, p, new_tail);
384 if (!err)
385 lp->flags &= ~LDC_FLAG_RESET;
386 return err;
387 }
388 return -EBUSY;
389 }
390
391 static int send_version_nack(struct ldc_channel *lp,
392 u16 major, u16 minor)
393 {
394 struct ldc_packet *p;
395 struct ldc_version ver;
396 unsigned long new_tail;
397
398 ver.major = major;
399 ver.minor = minor;
400
401 p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
402 &ver, sizeof(ver), &new_tail);
403 if (p) {
404 ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
405 ver.major, ver.minor);
406
407 return send_tx_packet(lp, p, new_tail);
408 }
409 return -EBUSY;
410 }
411
412 static int send_version_ack(struct ldc_channel *lp,
413 struct ldc_version *vp)
414 {
415 struct ldc_packet *p;
416 unsigned long new_tail;
417
418 p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
419 vp, sizeof(*vp), &new_tail);
420 if (p) {
421 ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
422 vp->major, vp->minor);
423
424 return send_tx_packet(lp, p, new_tail);
425 }
426 return -EBUSY;
427 }
428
429 static int send_rts(struct ldc_channel *lp)
430 {
431 struct ldc_packet *p;
432 unsigned long new_tail;
433
434 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
435 &new_tail);
436 if (p) {
437 p->env = lp->cfg.mode;
438 p->seqid = 0;
439 lp->rcv_nxt = 0;
440
441 ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
442 p->env, p->seqid);
443
444 return send_tx_packet(lp, p, new_tail);
445 }
446 return -EBUSY;
447 }
448
449 static int send_rtr(struct ldc_channel *lp)
450 {
451 struct ldc_packet *p;
452 unsigned long new_tail;
453
454 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
455 &new_tail);
456 if (p) {
457 p->env = lp->cfg.mode;
458 p->seqid = 0;
459
460 ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
461 p->env, p->seqid);
462
463 return send_tx_packet(lp, p, new_tail);
464 }
465 return -EBUSY;
466 }
467
468 static int send_rdx(struct ldc_channel *lp)
469 {
470 struct ldc_packet *p;
471 unsigned long new_tail;
472
473 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
474 &new_tail);
475 if (p) {
476 p->env = 0;
477 p->seqid = ++lp->snd_nxt;
478 p->u.r.ackid = lp->rcv_nxt;
479
480 ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
481 p->env, p->seqid, p->u.r.ackid);
482
483 return send_tx_packet(lp, p, new_tail);
484 }
485 return -EBUSY;
486 }
487
488 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
489 {
490 struct ldc_packet *p;
491 unsigned long new_tail;
492 int err;
493
494 p = data_get_tx_packet(lp, &new_tail);
495 if (!p)
496 return -EBUSY;
497 memset(p, 0, sizeof(*p));
498 p->type = data_pkt->type;
499 p->stype = LDC_NACK;
500 p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
501 p->seqid = lp->snd_nxt + 1;
502 p->u.r.ackid = lp->rcv_nxt;
503
504 ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
505 p->type, p->ctrl, p->seqid, p->u.r.ackid);
506
507 err = send_tx_packet(lp, p, new_tail);
508 if (!err)
509 lp->snd_nxt++;
510
511 return err;
512 }
513
514 static int ldc_abort(struct ldc_channel *lp)
515 {
516 unsigned long hv_err;
517
518 ldcdbg(STATE, "ABORT\n");
519
520 /* We report but do not act upon the hypervisor errors because
521 * there really isn't much we can do if they fail at this point.
522 */
523 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
524 if (hv_err)
525 printk(KERN_ERR PFX "ldc_abort: "
526 "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
527 lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
528
529 hv_err = sun4v_ldc_tx_get_state(lp->id,
530 &lp->tx_head,
531 &lp->tx_tail,
532 &lp->chan_state);
533 if (hv_err)
534 printk(KERN_ERR PFX "ldc_abort: "
535 "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
536 lp->id, hv_err);
537
538 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
539 if (hv_err)
540 printk(KERN_ERR PFX "ldc_abort: "
541 "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
542 lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
543
544 /* Refetch the RX queue state as well, because we could be invoked
545 * here in the queue processing context.
546 */
547 hv_err = sun4v_ldc_rx_get_state(lp->id,
548 &lp->rx_head,
549 &lp->rx_tail,
550 &lp->chan_state);
551 if (hv_err)
552 printk(KERN_ERR PFX "ldc_abort: "
553 "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
554 lp->id, hv_err);
555
556 return -ECONNRESET;
557 }
558
559 static struct ldc_version *find_by_major(u16 major)
560 {
561 struct ldc_version *ret = NULL;
562 int i;
563
564 for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
565 struct ldc_version *v = &ver_arr[i];
566 if (v->major <= major) {
567 ret = v;
568 break;
569 }
570 }
571 return ret;
572 }
573
574 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
575 {
576 struct ldc_version *vap;
577 int err;
578
579 ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
580 vp->major, vp->minor);
581
582 if (lp->hs_state == LDC_HS_GOTVERS) {
583 lp->hs_state = LDC_HS_OPEN;
584 memset(&lp->ver, 0, sizeof(lp->ver));
585 }
586
587 vap = find_by_major(vp->major);
588 if (!vap) {
589 err = send_version_nack(lp, 0, 0);
590 } else if (vap->major != vp->major) {
591 err = send_version_nack(lp, vap->major, vap->minor);
592 } else {
593 struct ldc_version ver = *vp;
594 if (ver.minor > vap->minor)
595 ver.minor = vap->minor;
596 err = send_version_ack(lp, &ver);
597 if (!err) {
598 lp->ver = ver;
599 lp->hs_state = LDC_HS_GOTVERS;
600 }
601 }
602 if (err)
603 return ldc_abort(lp);
604
605 return 0;
606 }
607
608 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
609 {
610 ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
611 vp->major, vp->minor);
612
613 if (lp->hs_state == LDC_HS_GOTVERS) {
614 if (lp->ver.major != vp->major ||
615 lp->ver.minor != vp->minor)
616 return ldc_abort(lp);
617 } else {
618 lp->ver = *vp;
619 lp->hs_state = LDC_HS_GOTVERS;
620 }
621 if (send_rts(lp))
622 return ldc_abort(lp);
623 return 0;
624 }
625
626 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
627 {
628 struct ldc_version *vap;
629 struct ldc_packet *p;
630 unsigned long new_tail;
631
632 if (vp->major == 0 && vp->minor == 0)
633 return ldc_abort(lp);
634
635 vap = find_by_major(vp->major);
636 if (!vap)
637 return ldc_abort(lp);
638
639 p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
640 vap, sizeof(*vap),
641 &new_tail);
642 if (!p)
643 return ldc_abort(lp);
644
645 return send_tx_packet(lp, p, new_tail);
646 }
647
648 static int process_version(struct ldc_channel *lp,
649 struct ldc_packet *p)
650 {
651 struct ldc_version *vp;
652
653 vp = (struct ldc_version *) p->u.u_data;
654
655 switch (p->stype) {
656 case LDC_INFO:
657 return process_ver_info(lp, vp);
658
659 case LDC_ACK:
660 return process_ver_ack(lp, vp);
661
662 case LDC_NACK:
663 return process_ver_nack(lp, vp);
664
665 default:
666 return ldc_abort(lp);
667 }
668 }
669
670 static int process_rts(struct ldc_channel *lp,
671 struct ldc_packet *p)
672 {
673 ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
674 p->stype, p->seqid, p->env);
675
676 if (p->stype != LDC_INFO ||
677 lp->hs_state != LDC_HS_GOTVERS ||
678 p->env != lp->cfg.mode)
679 return ldc_abort(lp);
680
681 lp->snd_nxt = p->seqid;
682 lp->rcv_nxt = p->seqid;
683 lp->hs_state = LDC_HS_SENTRTR;
684 if (send_rtr(lp))
685 return ldc_abort(lp);
686
687 return 0;
688 }
689
690 static int process_rtr(struct ldc_channel *lp,
691 struct ldc_packet *p)
692 {
693 ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
694 p->stype, p->seqid, p->env);
695
696 if (p->stype != LDC_INFO ||
697 p->env != lp->cfg.mode)
698 return ldc_abort(lp);
699
700 lp->snd_nxt = p->seqid;
701 lp->hs_state = LDC_HS_COMPLETE;
702 ldc_set_state(lp, LDC_STATE_CONNECTED);
703 send_rdx(lp);
704
705 return LDC_EVENT_UP;
706 }
707
708 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
709 {
710 return lp->rcv_nxt + 1 == seqid;
711 }
712
713 static int process_rdx(struct ldc_channel *lp,
714 struct ldc_packet *p)
715 {
716 ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
717 p->stype, p->seqid, p->env, p->u.r.ackid);
718
719 if (p->stype != LDC_INFO ||
720 !(rx_seq_ok(lp, p->seqid)))
721 return ldc_abort(lp);
722
723 lp->rcv_nxt = p->seqid;
724
725 lp->hs_state = LDC_HS_COMPLETE;
726 ldc_set_state(lp, LDC_STATE_CONNECTED);
727
728 return LDC_EVENT_UP;
729 }
730
731 static int process_control_frame(struct ldc_channel *lp,
732 struct ldc_packet *p)
733 {
734 switch (p->ctrl) {
735 case LDC_VERS:
736 return process_version(lp, p);
737
738 case LDC_RTS:
739 return process_rts(lp, p);
740
741 case LDC_RTR:
742 return process_rtr(lp, p);
743
744 case LDC_RDX:
745 return process_rdx(lp, p);
746
747 default:
748 return ldc_abort(lp);
749 }
750 }
751
752 static int process_error_frame(struct ldc_channel *lp,
753 struct ldc_packet *p)
754 {
755 return ldc_abort(lp);
756 }
757
758 static int process_data_ack(struct ldc_channel *lp,
759 struct ldc_packet *ack)
760 {
761 unsigned long head = lp->tx_acked;
762 u32 ackid = ack->u.r.ackid;
763
764 while (1) {
765 struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
766
767 head = tx_advance(lp, head);
768
769 if (p->seqid == ackid) {
770 lp->tx_acked = head;
771 return 0;
772 }
773 if (head == lp->tx_tail)
774 return ldc_abort(lp);
775 }
776
777 return 0;
778 }
779
780 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
781 {
782 if (event_mask & LDC_EVENT_RESET)
783 lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
784 if (event_mask & LDC_EVENT_UP)
785 lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
786 if (event_mask & LDC_EVENT_DATA_READY)
787 lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
788 }
789
790 static irqreturn_t ldc_rx(int irq, void *dev_id)
791 {
792 struct ldc_channel *lp = dev_id;
793 unsigned long orig_state, flags;
794 unsigned int event_mask;
795
796 spin_lock_irqsave(&lp->lock, flags);
797
798 orig_state = lp->chan_state;
799
800 /* We should probably check for hypervisor errors here and
801 * reset the LDC channel if we get one.
802 */
803 sun4v_ldc_rx_get_state(lp->id,
804 &lp->rx_head,
805 &lp->rx_tail,
806 &lp->chan_state);
807
808 ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
809 orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
810
811 event_mask = 0;
812
813 if (lp->cfg.mode == LDC_MODE_RAW &&
814 lp->chan_state == LDC_CHANNEL_UP) {
815 lp->hs_state = LDC_HS_COMPLETE;
816 ldc_set_state(lp, LDC_STATE_CONNECTED);
817
818 event_mask |= LDC_EVENT_UP;
819
820 orig_state = lp->chan_state;
821 }
822
823 /* If we are in reset state, flush the RX queue and ignore
824 * everything.
825 */
826 if (lp->flags & LDC_FLAG_RESET) {
827 (void) __set_rx_head(lp, lp->rx_tail);
828 goto out;
829 }
830
831 /* Once we finish the handshake, we let the ldc_read()
832 * paths do all of the control frame and state management.
833 * Just trigger the callback.
834 */
835 if (lp->hs_state == LDC_HS_COMPLETE) {
836 handshake_complete:
837 if (lp->chan_state != orig_state) {
838 unsigned int event = LDC_EVENT_RESET;
839
840 if (lp->chan_state == LDC_CHANNEL_UP)
841 event = LDC_EVENT_UP;
842
843 event_mask |= event;
844 }
845 if (lp->rx_head != lp->rx_tail)
846 event_mask |= LDC_EVENT_DATA_READY;
847
848 goto out;
849 }
850
851 if (lp->chan_state != orig_state)
852 goto out;
853
854 while (lp->rx_head != lp->rx_tail) {
855 struct ldc_packet *p;
856 unsigned long new;
857 int err;
858
859 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
860
861 switch (p->type) {
862 case LDC_CTRL:
863 err = process_control_frame(lp, p);
864 if (err > 0)
865 event_mask |= err;
866 break;
867
868 case LDC_DATA:
869 event_mask |= LDC_EVENT_DATA_READY;
870 err = 0;
871 break;
872
873 case LDC_ERR:
874 err = process_error_frame(lp, p);
875 break;
876
877 default:
878 err = ldc_abort(lp);
879 break;
880 }
881
882 if (err < 0)
883 break;
884
885 new = lp->rx_head;
886 new += LDC_PACKET_SIZE;
887 if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
888 new = 0;
889 lp->rx_head = new;
890
891 err = __set_rx_head(lp, new);
892 if (err < 0) {
893 (void) ldc_abort(lp);
894 break;
895 }
896 if (lp->hs_state == LDC_HS_COMPLETE)
897 goto handshake_complete;
898 }
899
900 out:
901 spin_unlock_irqrestore(&lp->lock, flags);
902
903 send_events(lp, event_mask);
904
905 return IRQ_HANDLED;
906 }
907
908 static irqreturn_t ldc_tx(int irq, void *dev_id)
909 {
910 struct ldc_channel *lp = dev_id;
911 unsigned long flags, orig_state;
912 unsigned int event_mask = 0;
913
914 spin_lock_irqsave(&lp->lock, flags);
915
916 orig_state = lp->chan_state;
917
918 /* We should probably check for hypervisor errors here and
919 * reset the LDC channel if we get one.
920 */
921 sun4v_ldc_tx_get_state(lp->id,
922 &lp->tx_head,
923 &lp->tx_tail,
924 &lp->chan_state);
925
926 ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
927 orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
928
929 if (lp->cfg.mode == LDC_MODE_RAW &&
930 lp->chan_state == LDC_CHANNEL_UP) {
931 lp->hs_state = LDC_HS_COMPLETE;
932 ldc_set_state(lp, LDC_STATE_CONNECTED);
933
934 event_mask |= LDC_EVENT_UP;
935 }
936
937 spin_unlock_irqrestore(&lp->lock, flags);
938
939 send_events(lp, event_mask);
940
941 return IRQ_HANDLED;
942 }
943
944 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
945 * XXX that addition and removal from the ldc_channel_list has
946 * XXX atomicity, otherwise the __ldc_channel_exists() check is
947 * XXX totally pointless as another thread can slip into ldc_alloc()
948 * XXX and add a channel with the same ID. There also needs to be
949 * XXX a spinlock for ldc_channel_list.
950 */
951 static HLIST_HEAD(ldc_channel_list);
952
953 static int __ldc_channel_exists(unsigned long id)
954 {
955 struct ldc_channel *lp;
956
957 hlist_for_each_entry(lp, &ldc_channel_list, list) {
958 if (lp->id == id)
959 return 1;
960 }
961 return 0;
962 }
963
964 static int alloc_queue(const char *name, unsigned long num_entries,
965 struct ldc_packet **base, unsigned long *ra)
966 {
967 unsigned long size, order;
968 void *q;
969
970 size = num_entries * LDC_PACKET_SIZE;
971 order = get_order(size);
972
973 q = (void *) __get_free_pages(GFP_KERNEL, order);
974 if (!q) {
975 printk(KERN_ERR PFX "Alloc of %s queue failed with "
976 "size=%lu order=%lu\n", name, size, order);
977 return -ENOMEM;
978 }
979
980 memset(q, 0, PAGE_SIZE << order);
981
982 *base = q;
983 *ra = __pa(q);
984
985 return 0;
986 }
987
988 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
989 {
990 unsigned long size, order;
991
992 if (!q)
993 return;
994
995 size = num_entries * LDC_PACKET_SIZE;
996 order = get_order(size);
997
998 free_pages((unsigned long)q, order);
999 }
1000
1001 /* XXX Make this configurable... XXX */
1002 #define LDC_IOTABLE_SIZE (8 * 1024)
1003
1004 static int ldc_iommu_init(struct ldc_channel *lp)
1005 {
1006 unsigned long sz, num_tsb_entries, tsbsize, order;
1007 struct ldc_iommu *iommu = &lp->iommu;
1008 struct ldc_mtable_entry *table;
1009 unsigned long hv_err;
1010 int err;
1011
1012 num_tsb_entries = LDC_IOTABLE_SIZE;
1013 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1014
1015 spin_lock_init(&iommu->lock);
1016
1017 sz = num_tsb_entries / 8;
1018 sz = (sz + 7UL) & ~7UL;
1019 iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1020 if (!iommu->arena.map) {
1021 printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1022 return -ENOMEM;
1023 }
1024
1025 iommu->arena.limit = num_tsb_entries;
1026
1027 order = get_order(tsbsize);
1028
1029 table = (struct ldc_mtable_entry *)
1030 __get_free_pages(GFP_KERNEL, order);
1031 err = -ENOMEM;
1032 if (!table) {
1033 printk(KERN_ERR PFX "Alloc of MTE table failed, "
1034 "size=%lu order=%lu\n", tsbsize, order);
1035 goto out_free_map;
1036 }
1037
1038 memset(table, 0, PAGE_SIZE << order);
1039
1040 iommu->page_table = table;
1041
1042 hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1043 num_tsb_entries);
1044 err = -EINVAL;
1045 if (hv_err)
1046 goto out_free_table;
1047
1048 return 0;
1049
1050 out_free_table:
1051 free_pages((unsigned long) table, order);
1052 iommu->page_table = NULL;
1053
1054 out_free_map:
1055 kfree(iommu->arena.map);
1056 iommu->arena.map = NULL;
1057
1058 return err;
1059 }
1060
1061 static void ldc_iommu_release(struct ldc_channel *lp)
1062 {
1063 struct ldc_iommu *iommu = &lp->iommu;
1064 unsigned long num_tsb_entries, tsbsize, order;
1065
1066 (void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1067
1068 num_tsb_entries = iommu->arena.limit;
1069 tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1070 order = get_order(tsbsize);
1071
1072 free_pages((unsigned long) iommu->page_table, order);
1073 iommu->page_table = NULL;
1074
1075 kfree(iommu->arena.map);
1076 iommu->arena.map = NULL;
1077 }
1078
1079 struct ldc_channel *ldc_alloc(unsigned long id,
1080 const struct ldc_channel_config *cfgp,
1081 void *event_arg)
1082 {
1083 struct ldc_channel *lp;
1084 const struct ldc_mode_ops *mops;
1085 unsigned long dummy1, dummy2, hv_err;
1086 u8 mss, *mssbuf;
1087 int err;
1088
1089 err = -ENODEV;
1090 if (!ldom_domaining_enabled)
1091 goto out_err;
1092
1093 err = -EINVAL;
1094 if (!cfgp)
1095 goto out_err;
1096
1097 switch (cfgp->mode) {
1098 case LDC_MODE_RAW:
1099 mops = &raw_ops;
1100 mss = LDC_PACKET_SIZE;
1101 break;
1102
1103 case LDC_MODE_UNRELIABLE:
1104 mops = &nonraw_ops;
1105 mss = LDC_PACKET_SIZE - 8;
1106 break;
1107
1108 case LDC_MODE_STREAM:
1109 mops = &stream_ops;
1110 mss = LDC_PACKET_SIZE - 8 - 8;
1111 break;
1112
1113 default:
1114 goto out_err;
1115 }
1116
1117 if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1118 goto out_err;
1119
1120 hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1121 err = -ENODEV;
1122 if (hv_err == HV_ECHANNEL)
1123 goto out_err;
1124
1125 err = -EEXIST;
1126 if (__ldc_channel_exists(id))
1127 goto out_err;
1128
1129 mssbuf = NULL;
1130
1131 lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1132 err = -ENOMEM;
1133 if (!lp)
1134 goto out_err;
1135
1136 spin_lock_init(&lp->lock);
1137
1138 lp->id = id;
1139
1140 err = ldc_iommu_init(lp);
1141 if (err)
1142 goto out_free_ldc;
1143
1144 lp->mops = mops;
1145 lp->mss = mss;
1146
1147 lp->cfg = *cfgp;
1148 if (!lp->cfg.mtu)
1149 lp->cfg.mtu = LDC_DEFAULT_MTU;
1150
1151 if (lp->cfg.mode == LDC_MODE_STREAM) {
1152 mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1153 if (!mssbuf) {
1154 err = -ENOMEM;
1155 goto out_free_iommu;
1156 }
1157 lp->mssbuf = mssbuf;
1158 }
1159
1160 lp->event_arg = event_arg;
1161
1162 /* XXX allow setting via ldc_channel_config to override defaults
1163 * XXX or use some formula based upon mtu
1164 */
1165 lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1166 lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1167
1168 err = alloc_queue("TX", lp->tx_num_entries,
1169 &lp->tx_base, &lp->tx_ra);
1170 if (err)
1171 goto out_free_mssbuf;
1172
1173 err = alloc_queue("RX", lp->rx_num_entries,
1174 &lp->rx_base, &lp->rx_ra);
1175 if (err)
1176 goto out_free_txq;
1177
1178 lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1179
1180 lp->hs_state = LDC_HS_CLOSED;
1181 ldc_set_state(lp, LDC_STATE_INIT);
1182
1183 INIT_HLIST_NODE(&lp->list);
1184 hlist_add_head(&lp->list, &ldc_channel_list);
1185
1186 INIT_HLIST_HEAD(&lp->mh_list);
1187
1188 return lp;
1189
1190 out_free_txq:
1191 free_queue(lp->tx_num_entries, lp->tx_base);
1192
1193 out_free_mssbuf:
1194 kfree(mssbuf);
1195
1196 out_free_iommu:
1197 ldc_iommu_release(lp);
1198
1199 out_free_ldc:
1200 kfree(lp);
1201
1202 out_err:
1203 return ERR_PTR(err);
1204 }
1205 EXPORT_SYMBOL(ldc_alloc);
1206
1207 void ldc_free(struct ldc_channel *lp)
1208 {
1209 if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1210 free_irq(lp->cfg.rx_irq, lp);
1211 free_irq(lp->cfg.tx_irq, lp);
1212 }
1213
1214 if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1215 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1216 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1217 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1218 }
1219 if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1220 free_queue(lp->tx_num_entries, lp->tx_base);
1221 free_queue(lp->rx_num_entries, lp->rx_base);
1222 lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1223 }
1224
1225 hlist_del(&lp->list);
1226
1227 kfree(lp->mssbuf);
1228
1229 ldc_iommu_release(lp);
1230
1231 kfree(lp);
1232 }
1233 EXPORT_SYMBOL(ldc_free);
1234
1235 /* Bind the channel. This registers the LDC queues with
1236 * the hypervisor and puts the channel into a pseudo-listening
1237 * state. This does not initiate a handshake, ldc_connect() does
1238 * that.
1239 */
1240 int ldc_bind(struct ldc_channel *lp, const char *name)
1241 {
1242 unsigned long hv_err, flags;
1243 int err = -EINVAL;
1244
1245 if (!name ||
1246 (lp->state != LDC_STATE_INIT))
1247 return -EINVAL;
1248
1249 snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1250 snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1251
1252 err = request_irq(lp->cfg.rx_irq, ldc_rx, IRQF_DISABLED,
1253 lp->rx_irq_name, lp);
1254 if (err)
1255 return err;
1256
1257 err = request_irq(lp->cfg.tx_irq, ldc_tx, IRQF_DISABLED,
1258 lp->tx_irq_name, lp);
1259 if (err) {
1260 free_irq(lp->cfg.rx_irq, lp);
1261 return err;
1262 }
1263
1264
1265 spin_lock_irqsave(&lp->lock, flags);
1266
1267 enable_irq(lp->cfg.rx_irq);
1268 enable_irq(lp->cfg.tx_irq);
1269
1270 lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1271
1272 err = -ENODEV;
1273 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1274 if (hv_err)
1275 goto out_free_irqs;
1276
1277 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1278 if (hv_err)
1279 goto out_free_irqs;
1280
1281 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1282 if (hv_err)
1283 goto out_unmap_tx;
1284
1285 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1286 if (hv_err)
1287 goto out_unmap_tx;
1288
1289 lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1290
1291 hv_err = sun4v_ldc_tx_get_state(lp->id,
1292 &lp->tx_head,
1293 &lp->tx_tail,
1294 &lp->chan_state);
1295 err = -EBUSY;
1296 if (hv_err)
1297 goto out_unmap_rx;
1298
1299 lp->tx_acked = lp->tx_head;
1300
1301 lp->hs_state = LDC_HS_OPEN;
1302 ldc_set_state(lp, LDC_STATE_BOUND);
1303
1304 spin_unlock_irqrestore(&lp->lock, flags);
1305
1306 return 0;
1307
1308 out_unmap_rx:
1309 lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1310 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1311
1312 out_unmap_tx:
1313 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1314
1315 out_free_irqs:
1316 lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1317 free_irq(lp->cfg.tx_irq, lp);
1318 free_irq(lp->cfg.rx_irq, lp);
1319
1320 spin_unlock_irqrestore(&lp->lock, flags);
1321
1322 return err;
1323 }
1324 EXPORT_SYMBOL(ldc_bind);
1325
1326 int ldc_connect(struct ldc_channel *lp)
1327 {
1328 unsigned long flags;
1329 int err;
1330
1331 if (lp->cfg.mode == LDC_MODE_RAW)
1332 return -EINVAL;
1333
1334 spin_lock_irqsave(&lp->lock, flags);
1335
1336 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1337 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1338 lp->hs_state != LDC_HS_OPEN)
1339 err = -EINVAL;
1340 else
1341 err = start_handshake(lp);
1342
1343 spin_unlock_irqrestore(&lp->lock, flags);
1344
1345 return err;
1346 }
1347 EXPORT_SYMBOL(ldc_connect);
1348
1349 int ldc_disconnect(struct ldc_channel *lp)
1350 {
1351 unsigned long hv_err, flags;
1352 int err;
1353
1354 if (lp->cfg.mode == LDC_MODE_RAW)
1355 return -EINVAL;
1356
1357 if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1358 !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1359 return -EINVAL;
1360
1361 spin_lock_irqsave(&lp->lock, flags);
1362
1363 err = -ENODEV;
1364 hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1365 if (hv_err)
1366 goto out_err;
1367
1368 hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1369 if (hv_err)
1370 goto out_err;
1371
1372 hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1373 if (hv_err)
1374 goto out_err;
1375
1376 hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1377 if (hv_err)
1378 goto out_err;
1379
1380 ldc_set_state(lp, LDC_STATE_BOUND);
1381 lp->hs_state = LDC_HS_OPEN;
1382 lp->flags |= LDC_FLAG_RESET;
1383
1384 spin_unlock_irqrestore(&lp->lock, flags);
1385
1386 return 0;
1387
1388 out_err:
1389 sun4v_ldc_tx_qconf(lp->id, 0, 0);
1390 sun4v_ldc_rx_qconf(lp->id, 0, 0);
1391 free_irq(lp->cfg.tx_irq, lp);
1392 free_irq(lp->cfg.rx_irq, lp);
1393 lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1394 LDC_FLAG_REGISTERED_QUEUES);
1395 ldc_set_state(lp, LDC_STATE_INIT);
1396
1397 spin_unlock_irqrestore(&lp->lock, flags);
1398
1399 return err;
1400 }
1401 EXPORT_SYMBOL(ldc_disconnect);
1402
1403 int ldc_state(struct ldc_channel *lp)
1404 {
1405 return lp->state;
1406 }
1407 EXPORT_SYMBOL(ldc_state);
1408
1409 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1410 {
1411 struct ldc_packet *p;
1412 unsigned long new_tail;
1413 int err;
1414
1415 if (size > LDC_PACKET_SIZE)
1416 return -EMSGSIZE;
1417
1418 p = data_get_tx_packet(lp, &new_tail);
1419 if (!p)
1420 return -EAGAIN;
1421
1422 memcpy(p, buf, size);
1423
1424 err = send_tx_packet(lp, p, new_tail);
1425 if (!err)
1426 err = size;
1427
1428 return err;
1429 }
1430
1431 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1432 {
1433 struct ldc_packet *p;
1434 unsigned long hv_err, new;
1435 int err;
1436
1437 if (size < LDC_PACKET_SIZE)
1438 return -EINVAL;
1439
1440 hv_err = sun4v_ldc_rx_get_state(lp->id,
1441 &lp->rx_head,
1442 &lp->rx_tail,
1443 &lp->chan_state);
1444 if (hv_err)
1445 return ldc_abort(lp);
1446
1447 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1448 lp->chan_state == LDC_CHANNEL_RESETTING)
1449 return -ECONNRESET;
1450
1451 if (lp->rx_head == lp->rx_tail)
1452 return 0;
1453
1454 p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1455 memcpy(buf, p, LDC_PACKET_SIZE);
1456
1457 new = rx_advance(lp, lp->rx_head);
1458 lp->rx_head = new;
1459
1460 err = __set_rx_head(lp, new);
1461 if (err < 0)
1462 err = -ECONNRESET;
1463 else
1464 err = LDC_PACKET_SIZE;
1465
1466 return err;
1467 }
1468
1469 static const struct ldc_mode_ops raw_ops = {
1470 .write = write_raw,
1471 .read = read_raw,
1472 };
1473
1474 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1475 unsigned int size)
1476 {
1477 unsigned long hv_err, tail;
1478 unsigned int copied;
1479 u32 seq;
1480 int err;
1481
1482 hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1483 &lp->chan_state);
1484 if (unlikely(hv_err))
1485 return -EBUSY;
1486
1487 if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1488 return ldc_abort(lp);
1489
1490 if (!tx_has_space_for(lp, size))
1491 return -EAGAIN;
1492
1493 seq = lp->snd_nxt;
1494 copied = 0;
1495 tail = lp->tx_tail;
1496 while (copied < size) {
1497 struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1498 u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1499 p->u.u_data :
1500 p->u.r.r_data);
1501 int data_len;
1502
1503 p->type = LDC_DATA;
1504 p->stype = LDC_INFO;
1505 p->ctrl = 0;
1506
1507 data_len = size - copied;
1508 if (data_len > lp->mss)
1509 data_len = lp->mss;
1510
1511 BUG_ON(data_len > LDC_LEN);
1512
1513 p->env = (data_len |
1514 (copied == 0 ? LDC_START : 0) |
1515 (data_len == size - copied ? LDC_STOP : 0));
1516
1517 p->seqid = ++seq;
1518
1519 ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1520 p->type,
1521 p->stype,
1522 p->ctrl,
1523 p->env,
1524 p->seqid);
1525
1526 memcpy(data, buf, data_len);
1527 buf += data_len;
1528 copied += data_len;
1529
1530 tail = tx_advance(lp, tail);
1531 }
1532
1533 err = set_tx_tail(lp, tail);
1534 if (!err) {
1535 lp->snd_nxt = seq;
1536 err = size;
1537 }
1538
1539 return err;
1540 }
1541
1542 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1543 struct ldc_packet *first_frag)
1544 {
1545 int err;
1546
1547 if (first_frag)
1548 lp->rcv_nxt = first_frag->seqid - 1;
1549
1550 err = send_data_nack(lp, p);
1551 if (err)
1552 return err;
1553
1554 err = __set_rx_head(lp, lp->rx_tail);
1555 if (err < 0)
1556 return ldc_abort(lp);
1557
1558 return 0;
1559 }
1560
1561 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1562 {
1563 if (p->stype & LDC_ACK) {
1564 int err = process_data_ack(lp, p);
1565 if (err)
1566 return err;
1567 }
1568 if (p->stype & LDC_NACK)
1569 return ldc_abort(lp);
1570
1571 return 0;
1572 }
1573
1574 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1575 {
1576 unsigned long dummy;
1577 int limit = 1000;
1578
1579 ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1580 cur_head, lp->rx_head, lp->rx_tail);
1581 while (limit-- > 0) {
1582 unsigned long hv_err;
1583
1584 hv_err = sun4v_ldc_rx_get_state(lp->id,
1585 &dummy,
1586 &lp->rx_tail,
1587 &lp->chan_state);
1588 if (hv_err)
1589 return ldc_abort(lp);
1590
1591 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1592 lp->chan_state == LDC_CHANNEL_RESETTING)
1593 return -ECONNRESET;
1594
1595 if (cur_head != lp->rx_tail) {
1596 ldcdbg(DATA, "DATA WAIT DONE "
1597 "head[%lx] tail[%lx] chan_state[%lx]\n",
1598 dummy, lp->rx_tail, lp->chan_state);
1599 return 0;
1600 }
1601
1602 udelay(1);
1603 }
1604 return -EAGAIN;
1605 }
1606
1607 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1608 {
1609 int err = __set_rx_head(lp, head);
1610
1611 if (err < 0)
1612 return ldc_abort(lp);
1613
1614 lp->rx_head = head;
1615 return 0;
1616 }
1617
1618 static void send_data_ack(struct ldc_channel *lp)
1619 {
1620 unsigned long new_tail;
1621 struct ldc_packet *p;
1622
1623 p = data_get_tx_packet(lp, &new_tail);
1624 if (likely(p)) {
1625 int err;
1626
1627 memset(p, 0, sizeof(*p));
1628 p->type = LDC_DATA;
1629 p->stype = LDC_ACK;
1630 p->ctrl = 0;
1631 p->seqid = lp->snd_nxt + 1;
1632 p->u.r.ackid = lp->rcv_nxt;
1633
1634 err = send_tx_packet(lp, p, new_tail);
1635 if (!err)
1636 lp->snd_nxt++;
1637 }
1638 }
1639
1640 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1641 {
1642 struct ldc_packet *first_frag;
1643 unsigned long hv_err, new;
1644 int err, copied;
1645
1646 hv_err = sun4v_ldc_rx_get_state(lp->id,
1647 &lp->rx_head,
1648 &lp->rx_tail,
1649 &lp->chan_state);
1650 if (hv_err)
1651 return ldc_abort(lp);
1652
1653 if (lp->chan_state == LDC_CHANNEL_DOWN ||
1654 lp->chan_state == LDC_CHANNEL_RESETTING)
1655 return -ECONNRESET;
1656
1657 if (lp->rx_head == lp->rx_tail)
1658 return 0;
1659
1660 first_frag = NULL;
1661 copied = err = 0;
1662 new = lp->rx_head;
1663 while (1) {
1664 struct ldc_packet *p;
1665 int pkt_len;
1666
1667 BUG_ON(new == lp->rx_tail);
1668 p = lp->rx_base + (new / LDC_PACKET_SIZE);
1669
1670 ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1671 "rcv_nxt[%08x]\n",
1672 p->type,
1673 p->stype,
1674 p->ctrl,
1675 p->env,
1676 p->seqid,
1677 p->u.r.ackid,
1678 lp->rcv_nxt);
1679
1680 if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1681 err = rx_bad_seq(lp, p, first_frag);
1682 copied = 0;
1683 break;
1684 }
1685
1686 if (p->type & LDC_CTRL) {
1687 err = process_control_frame(lp, p);
1688 if (err < 0)
1689 break;
1690 err = 0;
1691 }
1692
1693 lp->rcv_nxt = p->seqid;
1694
1695 if (!(p->type & LDC_DATA)) {
1696 new = rx_advance(lp, new);
1697 goto no_data;
1698 }
1699 if (p->stype & (LDC_ACK | LDC_NACK)) {
1700 err = data_ack_nack(lp, p);
1701 if (err)
1702 break;
1703 }
1704 if (!(p->stype & LDC_INFO)) {
1705 new = rx_advance(lp, new);
1706 err = rx_set_head(lp, new);
1707 if (err)
1708 break;
1709 goto no_data;
1710 }
1711
1712 pkt_len = p->env & LDC_LEN;
1713
1714 /* Every initial packet starts with the START bit set.
1715 *
1716 * Singleton packets will have both START+STOP set.
1717 *
1718 * Fragments will have START set in the first frame, STOP
1719 * set in the last frame, and neither bit set in middle
1720 * frames of the packet.
1721 *
1722 * Therefore if we are at the beginning of a packet and
1723 * we don't see START, or we are in the middle of a fragmented
1724 * packet and do see START, we are unsynchronized and should
1725 * flush the RX queue.
1726 */
1727 if ((first_frag == NULL && !(p->env & LDC_START)) ||
1728 (first_frag != NULL && (p->env & LDC_START))) {
1729 if (!first_frag)
1730 new = rx_advance(lp, new);
1731
1732 err = rx_set_head(lp, new);
1733 if (err)
1734 break;
1735
1736 if (!first_frag)
1737 goto no_data;
1738 }
1739 if (!first_frag)
1740 first_frag = p;
1741
1742 if (pkt_len > size - copied) {
1743 /* User didn't give us a big enough buffer,
1744 * what to do? This is a pretty serious error.
1745 *
1746 * Since we haven't updated the RX ring head to
1747 * consume any of the packets, signal the error
1748 * to the user and just leave the RX ring alone.
1749 *
1750 * This seems the best behavior because this allows
1751 * a user of the LDC layer to start with a small
1752 * RX buffer for ldc_read() calls and use -EMSGSIZE
1753 * as a cue to enlarge it's read buffer.
1754 */
1755 err = -EMSGSIZE;
1756 break;
1757 }
1758
1759 /* Ok, we are gonna eat this one. */
1760 new = rx_advance(lp, new);
1761
1762 memcpy(buf,
1763 (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1764 p->u.u_data : p->u.r.r_data), pkt_len);
1765 buf += pkt_len;
1766 copied += pkt_len;
1767
1768 if (p->env & LDC_STOP)
1769 break;
1770
1771 no_data:
1772 if (new == lp->rx_tail) {
1773 err = rx_data_wait(lp, new);
1774 if (err)
1775 break;
1776 }
1777 }
1778
1779 if (!err)
1780 err = rx_set_head(lp, new);
1781
1782 if (err && first_frag)
1783 lp->rcv_nxt = first_frag->seqid - 1;
1784
1785 if (!err) {
1786 err = copied;
1787 if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1788 send_data_ack(lp);
1789 }
1790
1791 return err;
1792 }
1793
1794 static const struct ldc_mode_ops nonraw_ops = {
1795 .write = write_nonraw,
1796 .read = read_nonraw,
1797 };
1798
1799 static int write_stream(struct ldc_channel *lp, const void *buf,
1800 unsigned int size)
1801 {
1802 if (size > lp->cfg.mtu)
1803 size = lp->cfg.mtu;
1804 return write_nonraw(lp, buf, size);
1805 }
1806
1807 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1808 {
1809 if (!lp->mssbuf_len) {
1810 int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1811 if (err < 0)
1812 return err;
1813
1814 lp->mssbuf_len = err;
1815 lp->mssbuf_off = 0;
1816 }
1817
1818 if (size > lp->mssbuf_len)
1819 size = lp->mssbuf_len;
1820 memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1821
1822 lp->mssbuf_off += size;
1823 lp->mssbuf_len -= size;
1824
1825 return size;
1826 }
1827
1828 static const struct ldc_mode_ops stream_ops = {
1829 .write = write_stream,
1830 .read = read_stream,
1831 };
1832
1833 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1834 {
1835 unsigned long flags;
1836 int err;
1837
1838 if (!buf)
1839 return -EINVAL;
1840
1841 if (!size)
1842 return 0;
1843
1844 spin_lock_irqsave(&lp->lock, flags);
1845
1846 if (lp->hs_state != LDC_HS_COMPLETE)
1847 err = -ENOTCONN;
1848 else
1849 err = lp->mops->write(lp, buf, size);
1850
1851 spin_unlock_irqrestore(&lp->lock, flags);
1852
1853 return err;
1854 }
1855 EXPORT_SYMBOL(ldc_write);
1856
1857 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1858 {
1859 unsigned long flags;
1860 int err;
1861
1862 if (!buf)
1863 return -EINVAL;
1864
1865 if (!size)
1866 return 0;
1867
1868 spin_lock_irqsave(&lp->lock, flags);
1869
1870 if (lp->hs_state != LDC_HS_COMPLETE)
1871 err = -ENOTCONN;
1872 else
1873 err = lp->mops->read(lp, buf, size);
1874
1875 spin_unlock_irqrestore(&lp->lock, flags);
1876
1877 return err;
1878 }
1879 EXPORT_SYMBOL(ldc_read);
1880
1881 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1882 {
1883 struct iommu_arena *arena = &iommu->arena;
1884 unsigned long n, start, end, limit;
1885 int pass;
1886
1887 limit = arena->limit;
1888 start = arena->hint;
1889 pass = 0;
1890
1891 again:
1892 n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1893 end = n + npages;
1894 if (unlikely(end >= limit)) {
1895 if (likely(pass < 1)) {
1896 limit = start;
1897 start = 0;
1898 pass++;
1899 goto again;
1900 } else {
1901 /* Scanned the whole thing, give up. */
1902 return -1;
1903 }
1904 }
1905 bitmap_set(arena->map, n, npages);
1906
1907 arena->hint = end;
1908
1909 return n;
1910 }
1911
1912 #define COOKIE_PGSZ_CODE 0xf000000000000000ULL
1913 #define COOKIE_PGSZ_CODE_SHIFT 60ULL
1914
1915 static u64 pagesize_code(void)
1916 {
1917 switch (PAGE_SIZE) {
1918 default:
1919 case (8ULL * 1024ULL):
1920 return 0;
1921 case (64ULL * 1024ULL):
1922 return 1;
1923 case (512ULL * 1024ULL):
1924 return 2;
1925 case (4ULL * 1024ULL * 1024ULL):
1926 return 3;
1927 case (32ULL * 1024ULL * 1024ULL):
1928 return 4;
1929 case (256ULL * 1024ULL * 1024ULL):
1930 return 5;
1931 }
1932 }
1933
1934 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1935 {
1936 return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1937 (index << PAGE_SHIFT) |
1938 page_offset);
1939 }
1940
1941 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1942 {
1943 u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1944
1945 cookie &= ~COOKIE_PGSZ_CODE;
1946
1947 *shift = szcode * 3;
1948
1949 return (cookie >> (13ULL + (szcode * 3ULL)));
1950 }
1951
1952 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1953 unsigned long npages)
1954 {
1955 long entry;
1956
1957 entry = arena_alloc(iommu, npages);
1958 if (unlikely(entry < 0))
1959 return NULL;
1960
1961 return iommu->page_table + entry;
1962 }
1963
1964 static u64 perm_to_mte(unsigned int map_perm)
1965 {
1966 u64 mte_base;
1967
1968 mte_base = pagesize_code();
1969
1970 if (map_perm & LDC_MAP_SHADOW) {
1971 if (map_perm & LDC_MAP_R)
1972 mte_base |= LDC_MTE_COPY_R;
1973 if (map_perm & LDC_MAP_W)
1974 mte_base |= LDC_MTE_COPY_W;
1975 }
1976 if (map_perm & LDC_MAP_DIRECT) {
1977 if (map_perm & LDC_MAP_R)
1978 mte_base |= LDC_MTE_READ;
1979 if (map_perm & LDC_MAP_W)
1980 mte_base |= LDC_MTE_WRITE;
1981 if (map_perm & LDC_MAP_X)
1982 mte_base |= LDC_MTE_EXEC;
1983 }
1984 if (map_perm & LDC_MAP_IO) {
1985 if (map_perm & LDC_MAP_R)
1986 mte_base |= LDC_MTE_IOMMU_R;
1987 if (map_perm & LDC_MAP_W)
1988 mte_base |= LDC_MTE_IOMMU_W;
1989 }
1990
1991 return mte_base;
1992 }
1993
1994 static int pages_in_region(unsigned long base, long len)
1995 {
1996 int count = 0;
1997
1998 do {
1999 unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
2000
2001 len -= (new - base);
2002 base = new;
2003 count++;
2004 } while (len > 0);
2005
2006 return count;
2007 }
2008
2009 struct cookie_state {
2010 struct ldc_mtable_entry *page_table;
2011 struct ldc_trans_cookie *cookies;
2012 u64 mte_base;
2013 u64 prev_cookie;
2014 u32 pte_idx;
2015 u32 nc;
2016 };
2017
2018 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2019 unsigned long off, unsigned long len)
2020 {
2021 do {
2022 unsigned long tlen, new = pa + PAGE_SIZE;
2023 u64 this_cookie;
2024
2025 sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2026
2027 tlen = PAGE_SIZE;
2028 if (off)
2029 tlen = PAGE_SIZE - off;
2030 if (tlen > len)
2031 tlen = len;
2032
2033 this_cookie = make_cookie(sp->pte_idx,
2034 pagesize_code(), off);
2035
2036 off = 0;
2037
2038 if (this_cookie == sp->prev_cookie) {
2039 sp->cookies[sp->nc - 1].cookie_size += tlen;
2040 } else {
2041 sp->cookies[sp->nc].cookie_addr = this_cookie;
2042 sp->cookies[sp->nc].cookie_size = tlen;
2043 sp->nc++;
2044 }
2045 sp->prev_cookie = this_cookie + tlen;
2046
2047 sp->pte_idx++;
2048
2049 len -= tlen;
2050 pa = new;
2051 } while (len > 0);
2052 }
2053
2054 static int sg_count_one(struct scatterlist *sg)
2055 {
2056 unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2057 long len = sg->length;
2058
2059 if ((sg->offset | len) & (8UL - 1))
2060 return -EFAULT;
2061
2062 return pages_in_region(base + sg->offset, len);
2063 }
2064
2065 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2066 {
2067 int count;
2068 int i;
2069
2070 count = 0;
2071 for (i = 0; i < num_sg; i++) {
2072 int err = sg_count_one(sg + i);
2073 if (err < 0)
2074 return err;
2075 count += err;
2076 }
2077
2078 return count;
2079 }
2080
2081 int ldc_map_sg(struct ldc_channel *lp,
2082 struct scatterlist *sg, int num_sg,
2083 struct ldc_trans_cookie *cookies, int ncookies,
2084 unsigned int map_perm)
2085 {
2086 unsigned long i, npages, flags;
2087 struct ldc_mtable_entry *base;
2088 struct cookie_state state;
2089 struct ldc_iommu *iommu;
2090 int err;
2091
2092 if (map_perm & ~LDC_MAP_ALL)
2093 return -EINVAL;
2094
2095 err = sg_count_pages(sg, num_sg);
2096 if (err < 0)
2097 return err;
2098
2099 npages = err;
2100 if (err > ncookies)
2101 return -EMSGSIZE;
2102
2103 iommu = &lp->iommu;
2104
2105 spin_lock_irqsave(&iommu->lock, flags);
2106 base = alloc_npages(iommu, npages);
2107 spin_unlock_irqrestore(&iommu->lock, flags);
2108
2109 if (!base)
2110 return -ENOMEM;
2111
2112 state.page_table = iommu->page_table;
2113 state.cookies = cookies;
2114 state.mte_base = perm_to_mte(map_perm);
2115 state.prev_cookie = ~(u64)0;
2116 state.pte_idx = (base - iommu->page_table);
2117 state.nc = 0;
2118
2119 for (i = 0; i < num_sg; i++)
2120 fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2121 sg[i].offset, sg[i].length);
2122
2123 return state.nc;
2124 }
2125 EXPORT_SYMBOL(ldc_map_sg);
2126
2127 int ldc_map_single(struct ldc_channel *lp,
2128 void *buf, unsigned int len,
2129 struct ldc_trans_cookie *cookies, int ncookies,
2130 unsigned int map_perm)
2131 {
2132 unsigned long npages, pa, flags;
2133 struct ldc_mtable_entry *base;
2134 struct cookie_state state;
2135 struct ldc_iommu *iommu;
2136
2137 if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2138 return -EINVAL;
2139
2140 pa = __pa(buf);
2141 if ((pa | len) & (8UL - 1))
2142 return -EFAULT;
2143
2144 npages = pages_in_region(pa, len);
2145
2146 iommu = &lp->iommu;
2147
2148 spin_lock_irqsave(&iommu->lock, flags);
2149 base = alloc_npages(iommu, npages);
2150 spin_unlock_irqrestore(&iommu->lock, flags);
2151
2152 if (!base)
2153 return -ENOMEM;
2154
2155 state.page_table = iommu->page_table;
2156 state.cookies = cookies;
2157 state.mte_base = perm_to_mte(map_perm);
2158 state.prev_cookie = ~(u64)0;
2159 state.pte_idx = (base - iommu->page_table);
2160 state.nc = 0;
2161 fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2162 BUG_ON(state.nc != 1);
2163
2164 return state.nc;
2165 }
2166 EXPORT_SYMBOL(ldc_map_single);
2167
2168 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2169 u64 cookie, u64 size)
2170 {
2171 struct iommu_arena *arena = &iommu->arena;
2172 unsigned long i, shift, index, npages;
2173 struct ldc_mtable_entry *base;
2174
2175 npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2176 index = cookie_to_index(cookie, &shift);
2177 base = iommu->page_table + index;
2178
2179 BUG_ON(index > arena->limit ||
2180 (index + npages) > arena->limit);
2181
2182 for (i = 0; i < npages; i++) {
2183 if (base->cookie)
2184 sun4v_ldc_revoke(id, cookie + (i << shift),
2185 base->cookie);
2186 base->mte = 0;
2187 __clear_bit(index + i, arena->map);
2188 }
2189 }
2190
2191 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2192 int ncookies)
2193 {
2194 struct ldc_iommu *iommu = &lp->iommu;
2195 unsigned long flags;
2196 int i;
2197
2198 spin_lock_irqsave(&iommu->lock, flags);
2199 for (i = 0; i < ncookies; i++) {
2200 u64 addr = cookies[i].cookie_addr;
2201 u64 size = cookies[i].cookie_size;
2202
2203 free_npages(lp->id, iommu, addr, size);
2204 }
2205 spin_unlock_irqrestore(&iommu->lock, flags);
2206 }
2207 EXPORT_SYMBOL(ldc_unmap);
2208
2209 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2210 void *buf, unsigned int len, unsigned long offset,
2211 struct ldc_trans_cookie *cookies, int ncookies)
2212 {
2213 unsigned int orig_len;
2214 unsigned long ra;
2215 int i;
2216
2217 if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2218 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2219 lp->id, copy_dir);
2220 return -EINVAL;
2221 }
2222
2223 ra = __pa(buf);
2224 if ((ra | len | offset) & (8UL - 1)) {
2225 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2226 "ra[%lx] len[%x] offset[%lx]\n",
2227 lp->id, ra, len, offset);
2228 return -EFAULT;
2229 }
2230
2231 if (lp->hs_state != LDC_HS_COMPLETE ||
2232 (lp->flags & LDC_FLAG_RESET)) {
2233 printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2234 "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2235 return -ECONNRESET;
2236 }
2237
2238 orig_len = len;
2239 for (i = 0; i < ncookies; i++) {
2240 unsigned long cookie_raddr = cookies[i].cookie_addr;
2241 unsigned long this_len = cookies[i].cookie_size;
2242 unsigned long actual_len;
2243
2244 if (unlikely(offset)) {
2245 unsigned long this_off = offset;
2246
2247 if (this_off > this_len)
2248 this_off = this_len;
2249
2250 offset -= this_off;
2251 this_len -= this_off;
2252 if (!this_len)
2253 continue;
2254 cookie_raddr += this_off;
2255 }
2256
2257 if (this_len > len)
2258 this_len = len;
2259
2260 while (1) {
2261 unsigned long hv_err;
2262
2263 hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2264 cookie_raddr, ra,
2265 this_len, &actual_len);
2266 if (unlikely(hv_err)) {
2267 printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2268 "HV error %lu\n",
2269 lp->id, hv_err);
2270 if (lp->hs_state != LDC_HS_COMPLETE ||
2271 (lp->flags & LDC_FLAG_RESET))
2272 return -ECONNRESET;
2273 else
2274 return -EFAULT;
2275 }
2276
2277 cookie_raddr += actual_len;
2278 ra += actual_len;
2279 len -= actual_len;
2280 if (actual_len == this_len)
2281 break;
2282
2283 this_len -= actual_len;
2284 }
2285
2286 if (!len)
2287 break;
2288 }
2289
2290 /* It is caller policy what to do about short copies.
2291 * For example, a networking driver can declare the
2292 * packet a runt and drop it.
2293 */
2294
2295 return orig_len - len;
2296 }
2297 EXPORT_SYMBOL(ldc_copy);
2298
2299 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2300 struct ldc_trans_cookie *cookies, int *ncookies,
2301 unsigned int map_perm)
2302 {
2303 void *buf;
2304 int err;
2305
2306 if (len & (8UL - 1))
2307 return ERR_PTR(-EINVAL);
2308
2309 buf = kzalloc(len, GFP_KERNEL);
2310 if (!buf)
2311 return ERR_PTR(-ENOMEM);
2312
2313 err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2314 if (err < 0) {
2315 kfree(buf);
2316 return ERR_PTR(err);
2317 }
2318 *ncookies = err;
2319
2320 return buf;
2321 }
2322 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2323
2324 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2325 struct ldc_trans_cookie *cookies, int ncookies)
2326 {
2327 ldc_unmap(lp, cookies, ncookies);
2328 kfree(buf);
2329 }
2330 EXPORT_SYMBOL(ldc_free_exp_dring);
2331
2332 static int __init ldc_init(void)
2333 {
2334 unsigned long major, minor;
2335 struct mdesc_handle *hp;
2336 const u64 *v;
2337 int err;
2338 u64 mp;
2339
2340 hp = mdesc_grab();
2341 if (!hp)
2342 return -ENODEV;
2343
2344 mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2345 err = -ENODEV;
2346 if (mp == MDESC_NODE_NULL)
2347 goto out;
2348
2349 v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2350 if (!v)
2351 goto out;
2352
2353 major = 1;
2354 minor = 0;
2355 if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2356 printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2357 goto out;
2358 }
2359
2360 printk(KERN_INFO "%s", version);
2361
2362 if (!*v) {
2363 printk(KERN_INFO PFX "Domaining disabled.\n");
2364 goto out;
2365 }
2366 ldom_domaining_enabled = 1;
2367 err = 0;
2368
2369 out:
2370 mdesc_release(hp);
2371 return err;
2372 }
2373
2374 core_initcall(ldc_init);
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