xref: /openbmc/linux/arch/sparc/kernel/ldc.c (revision 4dc7ccf7)
1 /* ldc.c: Logical Domain Channel link-layer protocol driver.
2  *
3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/delay.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/scatterlist.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/init.h>
17 #include <linux/bitmap.h>
18 
19 #include <asm/hypervisor.h>
20 #include <asm/iommu.h>
21 #include <asm/page.h>
22 #include <asm/ldc.h>
23 #include <asm/mdesc.h>
24 
25 #define DRV_MODULE_NAME		"ldc"
26 #define PFX DRV_MODULE_NAME	": "
27 #define DRV_MODULE_VERSION	"1.1"
28 #define DRV_MODULE_RELDATE	"July 22, 2008"
29 
30 static char version[] __devinitdata =
31 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
32 #define LDC_PACKET_SIZE		64
33 
34 /* Packet header layout for unreliable and reliable mode frames.
35  * When in RAW mode, packets are simply straight 64-byte payloads
36  * with no headers.
37  */
38 struct ldc_packet {
39 	u8			type;
40 #define LDC_CTRL		0x01
41 #define LDC_DATA		0x02
42 #define LDC_ERR			0x10
43 
44 	u8			stype;
45 #define LDC_INFO		0x01
46 #define LDC_ACK			0x02
47 #define LDC_NACK		0x04
48 
49 	u8			ctrl;
50 #define LDC_VERS		0x01 /* Link Version		*/
51 #define LDC_RTS			0x02 /* Request To Send		*/
52 #define LDC_RTR			0x03 /* Ready To Receive	*/
53 #define LDC_RDX			0x04 /* Ready for Data eXchange	*/
54 #define LDC_CTRL_MSK		0x0f
55 
56 	u8			env;
57 #define LDC_LEN			0x3f
58 #define LDC_FRAG_MASK		0xc0
59 #define LDC_START		0x40
60 #define LDC_STOP		0x80
61 
62 	u32			seqid;
63 
64 	union {
65 		u8		u_data[LDC_PACKET_SIZE - 8];
66 		struct {
67 			u32	pad;
68 			u32	ackid;
69 			u8	r_data[LDC_PACKET_SIZE - 8 - 8];
70 		} r;
71 	} u;
72 };
73 
74 struct ldc_version {
75 	u16 major;
76 	u16 minor;
77 };
78 
79 /* Ordered from largest major to lowest.  */
80 static struct ldc_version ver_arr[] = {
81 	{ .major = 1, .minor = 0 },
82 };
83 
84 #define LDC_DEFAULT_MTU			(4 * LDC_PACKET_SIZE)
85 #define LDC_DEFAULT_NUM_ENTRIES		(PAGE_SIZE / LDC_PACKET_SIZE)
86 
87 struct ldc_channel;
88 
89 struct ldc_mode_ops {
90 	int (*write)(struct ldc_channel *, const void *, unsigned int);
91 	int (*read)(struct ldc_channel *, void *, unsigned int);
92 };
93 
94 static const struct ldc_mode_ops raw_ops;
95 static const struct ldc_mode_ops nonraw_ops;
96 static const struct ldc_mode_ops stream_ops;
97 
98 int ldom_domaining_enabled;
99 
100 struct ldc_iommu {
101 	/* Protects arena alloc/free.  */
102 	spinlock_t			lock;
103 	struct iommu_arena		arena;
104 	struct ldc_mtable_entry		*page_table;
105 };
106 
107 struct ldc_channel {
108 	/* Protects all operations that depend upon channel state.  */
109 	spinlock_t			lock;
110 
111 	unsigned long			id;
112 
113 	u8				*mssbuf;
114 	u32				mssbuf_len;
115 	u32				mssbuf_off;
116 
117 	struct ldc_packet		*tx_base;
118 	unsigned long			tx_head;
119 	unsigned long			tx_tail;
120 	unsigned long			tx_num_entries;
121 	unsigned long			tx_ra;
122 
123 	unsigned long			tx_acked;
124 
125 	struct ldc_packet		*rx_base;
126 	unsigned long			rx_head;
127 	unsigned long			rx_tail;
128 	unsigned long			rx_num_entries;
129 	unsigned long			rx_ra;
130 
131 	u32				rcv_nxt;
132 	u32				snd_nxt;
133 
134 	unsigned long			chan_state;
135 
136 	struct ldc_channel_config	cfg;
137 	void				*event_arg;
138 
139 	const struct ldc_mode_ops	*mops;
140 
141 	struct ldc_iommu		iommu;
142 
143 	struct ldc_version		ver;
144 
145 	u8				hs_state;
146 #define LDC_HS_CLOSED			0x00
147 #define LDC_HS_OPEN			0x01
148 #define LDC_HS_GOTVERS			0x02
149 #define LDC_HS_SENTRTR			0x03
150 #define LDC_HS_GOTRTR			0x04
151 #define LDC_HS_COMPLETE			0x10
152 
153 	u8				flags;
154 #define LDC_FLAG_ALLOCED_QUEUES		0x01
155 #define LDC_FLAG_REGISTERED_QUEUES	0x02
156 #define LDC_FLAG_REGISTERED_IRQS	0x04
157 #define LDC_FLAG_RESET			0x10
158 
159 	u8				mss;
160 	u8				state;
161 
162 #define LDC_IRQ_NAME_MAX		32
163 	char				rx_irq_name[LDC_IRQ_NAME_MAX];
164 	char				tx_irq_name[LDC_IRQ_NAME_MAX];
165 
166 	struct hlist_head		mh_list;
167 
168 	struct hlist_node		list;
169 };
170 
171 #define ldcdbg(TYPE, f, a...) \
172 do {	if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
173 		printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
174 } while (0)
175 
176 static const char *state_to_str(u8 state)
177 {
178 	switch (state) {
179 	case LDC_STATE_INVALID:
180 		return "INVALID";
181 	case LDC_STATE_INIT:
182 		return "INIT";
183 	case LDC_STATE_BOUND:
184 		return "BOUND";
185 	case LDC_STATE_READY:
186 		return "READY";
187 	case LDC_STATE_CONNECTED:
188 		return "CONNECTED";
189 	default:
190 		return "<UNKNOWN>";
191 	}
192 }
193 
194 static void ldc_set_state(struct ldc_channel *lp, u8 state)
195 {
196 	ldcdbg(STATE, "STATE (%s) --> (%s)\n",
197 	       state_to_str(lp->state),
198 	       state_to_str(state));
199 
200 	lp->state = state;
201 }
202 
203 static unsigned long __advance(unsigned long off, unsigned long num_entries)
204 {
205 	off += LDC_PACKET_SIZE;
206 	if (off == (num_entries * LDC_PACKET_SIZE))
207 		off = 0;
208 
209 	return off;
210 }
211 
212 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
213 {
214 	return __advance(off, lp->rx_num_entries);
215 }
216 
217 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
218 {
219 	return __advance(off, lp->tx_num_entries);
220 }
221 
222 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
223 						  unsigned long *new_tail)
224 {
225 	struct ldc_packet *p;
226 	unsigned long t;
227 
228 	t = tx_advance(lp, lp->tx_tail);
229 	if (t == lp->tx_head)
230 		return NULL;
231 
232 	*new_tail = t;
233 
234 	p = lp->tx_base;
235 	return p + (lp->tx_tail / LDC_PACKET_SIZE);
236 }
237 
238 /* When we are in reliable or stream mode, have to track the next packet
239  * we haven't gotten an ACK for in the TX queue using tx_acked.  We have
240  * to be careful not to stomp over the queue past that point.  During
241  * the handshake, we don't have TX data packets pending in the queue
242  * and that's why handshake_get_tx_packet() need not be mindful of
243  * lp->tx_acked.
244  */
245 static unsigned long head_for_data(struct ldc_channel *lp)
246 {
247 	if (lp->cfg.mode == LDC_MODE_STREAM)
248 		return lp->tx_acked;
249 	return lp->tx_head;
250 }
251 
252 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
253 {
254 	unsigned long limit, tail, new_tail, diff;
255 	unsigned int mss;
256 
257 	limit = head_for_data(lp);
258 	tail = lp->tx_tail;
259 	new_tail = tx_advance(lp, tail);
260 	if (new_tail == limit)
261 		return 0;
262 
263 	if (limit > new_tail)
264 		diff = limit - new_tail;
265 	else
266 		diff = (limit +
267 			((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
268 	diff /= LDC_PACKET_SIZE;
269 	mss = lp->mss;
270 
271 	if (diff * mss < size)
272 		return 0;
273 
274 	return 1;
275 }
276 
277 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
278 					     unsigned long *new_tail)
279 {
280 	struct ldc_packet *p;
281 	unsigned long h, t;
282 
283 	h = head_for_data(lp);
284 	t = tx_advance(lp, lp->tx_tail);
285 	if (t == h)
286 		return NULL;
287 
288 	*new_tail = t;
289 
290 	p = lp->tx_base;
291 	return p + (lp->tx_tail / LDC_PACKET_SIZE);
292 }
293 
294 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
295 {
296 	unsigned long orig_tail = lp->tx_tail;
297 	int limit = 1000;
298 
299 	lp->tx_tail = tail;
300 	while (limit-- > 0) {
301 		unsigned long err;
302 
303 		err = sun4v_ldc_tx_set_qtail(lp->id, tail);
304 		if (!err)
305 			return 0;
306 
307 		if (err != HV_EWOULDBLOCK) {
308 			lp->tx_tail = orig_tail;
309 			return -EINVAL;
310 		}
311 		udelay(1);
312 	}
313 
314 	lp->tx_tail = orig_tail;
315 	return -EBUSY;
316 }
317 
318 /* This just updates the head value in the hypervisor using
319  * a polling loop with a timeout.  The caller takes care of
320  * upating software state representing the head change, if any.
321  */
322 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
323 {
324 	int limit = 1000;
325 
326 	while (limit-- > 0) {
327 		unsigned long err;
328 
329 		err = sun4v_ldc_rx_set_qhead(lp->id, head);
330 		if (!err)
331 			return 0;
332 
333 		if (err != HV_EWOULDBLOCK)
334 			return -EINVAL;
335 
336 		udelay(1);
337 	}
338 
339 	return -EBUSY;
340 }
341 
342 static int send_tx_packet(struct ldc_channel *lp,
343 			  struct ldc_packet *p,
344 			  unsigned long new_tail)
345 {
346 	BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
347 
348 	return set_tx_tail(lp, new_tail);
349 }
350 
351 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
352 						 u8 stype, u8 ctrl,
353 						 void *data, int dlen,
354 						 unsigned long *new_tail)
355 {
356 	struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
357 
358 	if (p) {
359 		memset(p, 0, sizeof(*p));
360 		p->type = LDC_CTRL;
361 		p->stype = stype;
362 		p->ctrl = ctrl;
363 		if (data)
364 			memcpy(p->u.u_data, data, dlen);
365 	}
366 	return p;
367 }
368 
369 static int start_handshake(struct ldc_channel *lp)
370 {
371 	struct ldc_packet *p;
372 	struct ldc_version *ver;
373 	unsigned long new_tail;
374 
375 	ver = &ver_arr[0];
376 
377 	ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
378 	       ver->major, ver->minor);
379 
380 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
381 				   ver, sizeof(*ver), &new_tail);
382 	if (p) {
383 		int err = send_tx_packet(lp, p, new_tail);
384 		if (!err)
385 			lp->flags &= ~LDC_FLAG_RESET;
386 		return err;
387 	}
388 	return -EBUSY;
389 }
390 
391 static int send_version_nack(struct ldc_channel *lp,
392 			     u16 major, u16 minor)
393 {
394 	struct ldc_packet *p;
395 	struct ldc_version ver;
396 	unsigned long new_tail;
397 
398 	ver.major = major;
399 	ver.minor = minor;
400 
401 	p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
402 				   &ver, sizeof(ver), &new_tail);
403 	if (p) {
404 		ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
405 		       ver.major, ver.minor);
406 
407 		return send_tx_packet(lp, p, new_tail);
408 	}
409 	return -EBUSY;
410 }
411 
412 static int send_version_ack(struct ldc_channel *lp,
413 			    struct ldc_version *vp)
414 {
415 	struct ldc_packet *p;
416 	unsigned long new_tail;
417 
418 	p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
419 				   vp, sizeof(*vp), &new_tail);
420 	if (p) {
421 		ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
422 		       vp->major, vp->minor);
423 
424 		return send_tx_packet(lp, p, new_tail);
425 	}
426 	return -EBUSY;
427 }
428 
429 static int send_rts(struct ldc_channel *lp)
430 {
431 	struct ldc_packet *p;
432 	unsigned long new_tail;
433 
434 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
435 				   &new_tail);
436 	if (p) {
437 		p->env = lp->cfg.mode;
438 		p->seqid = 0;
439 		lp->rcv_nxt = 0;
440 
441 		ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
442 		       p->env, p->seqid);
443 
444 		return send_tx_packet(lp, p, new_tail);
445 	}
446 	return -EBUSY;
447 }
448 
449 static int send_rtr(struct ldc_channel *lp)
450 {
451 	struct ldc_packet *p;
452 	unsigned long new_tail;
453 
454 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
455 				   &new_tail);
456 	if (p) {
457 		p->env = lp->cfg.mode;
458 		p->seqid = 0;
459 
460 		ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
461 		       p->env, p->seqid);
462 
463 		return send_tx_packet(lp, p, new_tail);
464 	}
465 	return -EBUSY;
466 }
467 
468 static int send_rdx(struct ldc_channel *lp)
469 {
470 	struct ldc_packet *p;
471 	unsigned long new_tail;
472 
473 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
474 				   &new_tail);
475 	if (p) {
476 		p->env = 0;
477 		p->seqid = ++lp->snd_nxt;
478 		p->u.r.ackid = lp->rcv_nxt;
479 
480 		ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
481 		       p->env, p->seqid, p->u.r.ackid);
482 
483 		return send_tx_packet(lp, p, new_tail);
484 	}
485 	return -EBUSY;
486 }
487 
488 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
489 {
490 	struct ldc_packet *p;
491 	unsigned long new_tail;
492 	int err;
493 
494 	p = data_get_tx_packet(lp, &new_tail);
495 	if (!p)
496 		return -EBUSY;
497 	memset(p, 0, sizeof(*p));
498 	p->type = data_pkt->type;
499 	p->stype = LDC_NACK;
500 	p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
501 	p->seqid = lp->snd_nxt + 1;
502 	p->u.r.ackid = lp->rcv_nxt;
503 
504 	ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
505 	       p->type, p->ctrl, p->seqid, p->u.r.ackid);
506 
507 	err = send_tx_packet(lp, p, new_tail);
508 	if (!err)
509 		lp->snd_nxt++;
510 
511 	return err;
512 }
513 
514 static int ldc_abort(struct ldc_channel *lp)
515 {
516 	unsigned long hv_err;
517 
518 	ldcdbg(STATE, "ABORT\n");
519 
520 	/* We report but do not act upon the hypervisor errors because
521 	 * there really isn't much we can do if they fail at this point.
522 	 */
523 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
524 	if (hv_err)
525 		printk(KERN_ERR PFX "ldc_abort: "
526 		       "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
527 		       lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
528 
529 	hv_err = sun4v_ldc_tx_get_state(lp->id,
530 					&lp->tx_head,
531 					&lp->tx_tail,
532 					&lp->chan_state);
533 	if (hv_err)
534 		printk(KERN_ERR PFX "ldc_abort: "
535 		       "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
536 		       lp->id, hv_err);
537 
538 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
539 	if (hv_err)
540 		printk(KERN_ERR PFX "ldc_abort: "
541 		       "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
542 		       lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
543 
544 	/* Refetch the RX queue state as well, because we could be invoked
545 	 * here in the queue processing context.
546 	 */
547 	hv_err = sun4v_ldc_rx_get_state(lp->id,
548 					&lp->rx_head,
549 					&lp->rx_tail,
550 					&lp->chan_state);
551 	if (hv_err)
552 		printk(KERN_ERR PFX "ldc_abort: "
553 		       "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
554 		       lp->id, hv_err);
555 
556 	return -ECONNRESET;
557 }
558 
559 static struct ldc_version *find_by_major(u16 major)
560 {
561 	struct ldc_version *ret = NULL;
562 	int i;
563 
564 	for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
565 		struct ldc_version *v = &ver_arr[i];
566 		if (v->major <= major) {
567 			ret = v;
568 			break;
569 		}
570 	}
571 	return ret;
572 }
573 
574 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
575 {
576 	struct ldc_version *vap;
577 	int err;
578 
579 	ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
580 	       vp->major, vp->minor);
581 
582 	if (lp->hs_state == LDC_HS_GOTVERS) {
583 		lp->hs_state = LDC_HS_OPEN;
584 		memset(&lp->ver, 0, sizeof(lp->ver));
585 	}
586 
587 	vap = find_by_major(vp->major);
588 	if (!vap) {
589 		err = send_version_nack(lp, 0, 0);
590 	} else if (vap->major != vp->major) {
591 		err = send_version_nack(lp, vap->major, vap->minor);
592 	} else {
593 		struct ldc_version ver = *vp;
594 		if (ver.minor > vap->minor)
595 			ver.minor = vap->minor;
596 		err = send_version_ack(lp, &ver);
597 		if (!err) {
598 			lp->ver = ver;
599 			lp->hs_state = LDC_HS_GOTVERS;
600 		}
601 	}
602 	if (err)
603 		return ldc_abort(lp);
604 
605 	return 0;
606 }
607 
608 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
609 {
610 	ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
611 	       vp->major, vp->minor);
612 
613 	if (lp->hs_state == LDC_HS_GOTVERS) {
614 		if (lp->ver.major != vp->major ||
615 		    lp->ver.minor != vp->minor)
616 			return ldc_abort(lp);
617 	} else {
618 		lp->ver = *vp;
619 		lp->hs_state = LDC_HS_GOTVERS;
620 	}
621 	if (send_rts(lp))
622 		return ldc_abort(lp);
623 	return 0;
624 }
625 
626 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
627 {
628 	struct ldc_version *vap;
629 	struct ldc_packet *p;
630 	unsigned long new_tail;
631 
632 	if (vp->major == 0 && vp->minor == 0)
633 		return ldc_abort(lp);
634 
635 	vap = find_by_major(vp->major);
636 	if (!vap)
637 		return ldc_abort(lp);
638 
639 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
640 					   vap, sizeof(*vap),
641 					   &new_tail);
642 	if (!p)
643 		return ldc_abort(lp);
644 
645 	return send_tx_packet(lp, p, new_tail);
646 }
647 
648 static int process_version(struct ldc_channel *lp,
649 			   struct ldc_packet *p)
650 {
651 	struct ldc_version *vp;
652 
653 	vp = (struct ldc_version *) p->u.u_data;
654 
655 	switch (p->stype) {
656 	case LDC_INFO:
657 		return process_ver_info(lp, vp);
658 
659 	case LDC_ACK:
660 		return process_ver_ack(lp, vp);
661 
662 	case LDC_NACK:
663 		return process_ver_nack(lp, vp);
664 
665 	default:
666 		return ldc_abort(lp);
667 	}
668 }
669 
670 static int process_rts(struct ldc_channel *lp,
671 		       struct ldc_packet *p)
672 {
673 	ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
674 	       p->stype, p->seqid, p->env);
675 
676 	if (p->stype     != LDC_INFO	   ||
677 	    lp->hs_state != LDC_HS_GOTVERS ||
678 	    p->env       != lp->cfg.mode)
679 		return ldc_abort(lp);
680 
681 	lp->snd_nxt = p->seqid;
682 	lp->rcv_nxt = p->seqid;
683 	lp->hs_state = LDC_HS_SENTRTR;
684 	if (send_rtr(lp))
685 		return ldc_abort(lp);
686 
687 	return 0;
688 }
689 
690 static int process_rtr(struct ldc_channel *lp,
691 		       struct ldc_packet *p)
692 {
693 	ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
694 	       p->stype, p->seqid, p->env);
695 
696 	if (p->stype     != LDC_INFO ||
697 	    p->env       != lp->cfg.mode)
698 		return ldc_abort(lp);
699 
700 	lp->snd_nxt = p->seqid;
701 	lp->hs_state = LDC_HS_COMPLETE;
702 	ldc_set_state(lp, LDC_STATE_CONNECTED);
703 	send_rdx(lp);
704 
705 	return LDC_EVENT_UP;
706 }
707 
708 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
709 {
710 	return lp->rcv_nxt + 1 == seqid;
711 }
712 
713 static int process_rdx(struct ldc_channel *lp,
714 		       struct ldc_packet *p)
715 {
716 	ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
717 	       p->stype, p->seqid, p->env, p->u.r.ackid);
718 
719 	if (p->stype != LDC_INFO ||
720 	    !(rx_seq_ok(lp, p->seqid)))
721 		return ldc_abort(lp);
722 
723 	lp->rcv_nxt = p->seqid;
724 
725 	lp->hs_state = LDC_HS_COMPLETE;
726 	ldc_set_state(lp, LDC_STATE_CONNECTED);
727 
728 	return LDC_EVENT_UP;
729 }
730 
731 static int process_control_frame(struct ldc_channel *lp,
732 				 struct ldc_packet *p)
733 {
734 	switch (p->ctrl) {
735 	case LDC_VERS:
736 		return process_version(lp, p);
737 
738 	case LDC_RTS:
739 		return process_rts(lp, p);
740 
741 	case LDC_RTR:
742 		return process_rtr(lp, p);
743 
744 	case LDC_RDX:
745 		return process_rdx(lp, p);
746 
747 	default:
748 		return ldc_abort(lp);
749 	}
750 }
751 
752 static int process_error_frame(struct ldc_channel *lp,
753 			       struct ldc_packet *p)
754 {
755 	return ldc_abort(lp);
756 }
757 
758 static int process_data_ack(struct ldc_channel *lp,
759 			    struct ldc_packet *ack)
760 {
761 	unsigned long head = lp->tx_acked;
762 	u32 ackid = ack->u.r.ackid;
763 
764 	while (1) {
765 		struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
766 
767 		head = tx_advance(lp, head);
768 
769 		if (p->seqid == ackid) {
770 			lp->tx_acked = head;
771 			return 0;
772 		}
773 		if (head == lp->tx_tail)
774 			return ldc_abort(lp);
775 	}
776 
777 	return 0;
778 }
779 
780 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
781 {
782 	if (event_mask & LDC_EVENT_RESET)
783 		lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
784 	if (event_mask & LDC_EVENT_UP)
785 		lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
786 	if (event_mask & LDC_EVENT_DATA_READY)
787 		lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
788 }
789 
790 static irqreturn_t ldc_rx(int irq, void *dev_id)
791 {
792 	struct ldc_channel *lp = dev_id;
793 	unsigned long orig_state, hv_err, flags;
794 	unsigned int event_mask;
795 
796 	spin_lock_irqsave(&lp->lock, flags);
797 
798 	orig_state = lp->chan_state;
799 	hv_err = sun4v_ldc_rx_get_state(lp->id,
800 					&lp->rx_head,
801 					&lp->rx_tail,
802 					&lp->chan_state);
803 
804 	ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
805 	       orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
806 
807 	event_mask = 0;
808 
809 	if (lp->cfg.mode == LDC_MODE_RAW &&
810 	    lp->chan_state == LDC_CHANNEL_UP) {
811 		lp->hs_state = LDC_HS_COMPLETE;
812 		ldc_set_state(lp, LDC_STATE_CONNECTED);
813 
814 		event_mask |= LDC_EVENT_UP;
815 
816 		orig_state = lp->chan_state;
817 	}
818 
819 	/* If we are in reset state, flush the RX queue and ignore
820 	 * everything.
821 	 */
822 	if (lp->flags & LDC_FLAG_RESET) {
823 		(void) __set_rx_head(lp, lp->rx_tail);
824 		goto out;
825 	}
826 
827 	/* Once we finish the handshake, we let the ldc_read()
828 	 * paths do all of the control frame and state management.
829 	 * Just trigger the callback.
830 	 */
831 	if (lp->hs_state == LDC_HS_COMPLETE) {
832 handshake_complete:
833 		if (lp->chan_state != orig_state) {
834 			unsigned int event = LDC_EVENT_RESET;
835 
836 			if (lp->chan_state == LDC_CHANNEL_UP)
837 				event = LDC_EVENT_UP;
838 
839 			event_mask |= event;
840 		}
841 		if (lp->rx_head != lp->rx_tail)
842 			event_mask |= LDC_EVENT_DATA_READY;
843 
844 		goto out;
845 	}
846 
847 	if (lp->chan_state != orig_state)
848 		goto out;
849 
850 	while (lp->rx_head != lp->rx_tail) {
851 		struct ldc_packet *p;
852 		unsigned long new;
853 		int err;
854 
855 		p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
856 
857 		switch (p->type) {
858 		case LDC_CTRL:
859 			err = process_control_frame(lp, p);
860 			if (err > 0)
861 				event_mask |= err;
862 			break;
863 
864 		case LDC_DATA:
865 			event_mask |= LDC_EVENT_DATA_READY;
866 			err = 0;
867 			break;
868 
869 		case LDC_ERR:
870 			err = process_error_frame(lp, p);
871 			break;
872 
873 		default:
874 			err = ldc_abort(lp);
875 			break;
876 		}
877 
878 		if (err < 0)
879 			break;
880 
881 		new = lp->rx_head;
882 		new += LDC_PACKET_SIZE;
883 		if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
884 			new = 0;
885 		lp->rx_head = new;
886 
887 		err = __set_rx_head(lp, new);
888 		if (err < 0) {
889 			(void) ldc_abort(lp);
890 			break;
891 		}
892 		if (lp->hs_state == LDC_HS_COMPLETE)
893 			goto handshake_complete;
894 	}
895 
896 out:
897 	spin_unlock_irqrestore(&lp->lock, flags);
898 
899 	send_events(lp, event_mask);
900 
901 	return IRQ_HANDLED;
902 }
903 
904 static irqreturn_t ldc_tx(int irq, void *dev_id)
905 {
906 	struct ldc_channel *lp = dev_id;
907 	unsigned long flags, hv_err, orig_state;
908 	unsigned int event_mask = 0;
909 
910 	spin_lock_irqsave(&lp->lock, flags);
911 
912 	orig_state = lp->chan_state;
913 	hv_err = sun4v_ldc_tx_get_state(lp->id,
914 					&lp->tx_head,
915 					&lp->tx_tail,
916 					&lp->chan_state);
917 
918 	ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
919 	       orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
920 
921 	if (lp->cfg.mode == LDC_MODE_RAW &&
922 	    lp->chan_state == LDC_CHANNEL_UP) {
923 		lp->hs_state = LDC_HS_COMPLETE;
924 		ldc_set_state(lp, LDC_STATE_CONNECTED);
925 
926 		event_mask |= LDC_EVENT_UP;
927 	}
928 
929 	spin_unlock_irqrestore(&lp->lock, flags);
930 
931 	send_events(lp, event_mask);
932 
933 	return IRQ_HANDLED;
934 }
935 
936 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
937  * XXX that addition and removal from the ldc_channel_list has
938  * XXX atomicity, otherwise the __ldc_channel_exists() check is
939  * XXX totally pointless as another thread can slip into ldc_alloc()
940  * XXX and add a channel with the same ID.  There also needs to be
941  * XXX a spinlock for ldc_channel_list.
942  */
943 static HLIST_HEAD(ldc_channel_list);
944 
945 static int __ldc_channel_exists(unsigned long id)
946 {
947 	struct ldc_channel *lp;
948 	struct hlist_node *n;
949 
950 	hlist_for_each_entry(lp, n, &ldc_channel_list, list) {
951 		if (lp->id == id)
952 			return 1;
953 	}
954 	return 0;
955 }
956 
957 static int alloc_queue(const char *name, unsigned long num_entries,
958 		       struct ldc_packet **base, unsigned long *ra)
959 {
960 	unsigned long size, order;
961 	void *q;
962 
963 	size = num_entries * LDC_PACKET_SIZE;
964 	order = get_order(size);
965 
966 	q = (void *) __get_free_pages(GFP_KERNEL, order);
967 	if (!q) {
968 		printk(KERN_ERR PFX "Alloc of %s queue failed with "
969 		       "size=%lu order=%lu\n", name, size, order);
970 		return -ENOMEM;
971 	}
972 
973 	memset(q, 0, PAGE_SIZE << order);
974 
975 	*base = q;
976 	*ra = __pa(q);
977 
978 	return 0;
979 }
980 
981 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
982 {
983 	unsigned long size, order;
984 
985 	if (!q)
986 		return;
987 
988 	size = num_entries * LDC_PACKET_SIZE;
989 	order = get_order(size);
990 
991 	free_pages((unsigned long)q, order);
992 }
993 
994 /* XXX Make this configurable... XXX */
995 #define LDC_IOTABLE_SIZE	(8 * 1024)
996 
997 static int ldc_iommu_init(struct ldc_channel *lp)
998 {
999 	unsigned long sz, num_tsb_entries, tsbsize, order;
1000 	struct ldc_iommu *iommu = &lp->iommu;
1001 	struct ldc_mtable_entry *table;
1002 	unsigned long hv_err;
1003 	int err;
1004 
1005 	num_tsb_entries = LDC_IOTABLE_SIZE;
1006 	tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1007 
1008 	spin_lock_init(&iommu->lock);
1009 
1010 	sz = num_tsb_entries / 8;
1011 	sz = (sz + 7UL) & ~7UL;
1012 	iommu->arena.map = kzalloc(sz, GFP_KERNEL);
1013 	if (!iommu->arena.map) {
1014 		printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1015 		return -ENOMEM;
1016 	}
1017 
1018 	iommu->arena.limit = num_tsb_entries;
1019 
1020 	order = get_order(tsbsize);
1021 
1022 	table = (struct ldc_mtable_entry *)
1023 		__get_free_pages(GFP_KERNEL, order);
1024 	err = -ENOMEM;
1025 	if (!table) {
1026 		printk(KERN_ERR PFX "Alloc of MTE table failed, "
1027 		       "size=%lu order=%lu\n", tsbsize, order);
1028 		goto out_free_map;
1029 	}
1030 
1031 	memset(table, 0, PAGE_SIZE << order);
1032 
1033 	iommu->page_table = table;
1034 
1035 	hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1036 					 num_tsb_entries);
1037 	err = -EINVAL;
1038 	if (hv_err)
1039 		goto out_free_table;
1040 
1041 	return 0;
1042 
1043 out_free_table:
1044 	free_pages((unsigned long) table, order);
1045 	iommu->page_table = NULL;
1046 
1047 out_free_map:
1048 	kfree(iommu->arena.map);
1049 	iommu->arena.map = NULL;
1050 
1051 	return err;
1052 }
1053 
1054 static void ldc_iommu_release(struct ldc_channel *lp)
1055 {
1056 	struct ldc_iommu *iommu = &lp->iommu;
1057 	unsigned long num_tsb_entries, tsbsize, order;
1058 
1059 	(void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1060 
1061 	num_tsb_entries = iommu->arena.limit;
1062 	tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1063 	order = get_order(tsbsize);
1064 
1065 	free_pages((unsigned long) iommu->page_table, order);
1066 	iommu->page_table = NULL;
1067 
1068 	kfree(iommu->arena.map);
1069 	iommu->arena.map = NULL;
1070 }
1071 
1072 struct ldc_channel *ldc_alloc(unsigned long id,
1073 			      const struct ldc_channel_config *cfgp,
1074 			      void *event_arg)
1075 {
1076 	struct ldc_channel *lp;
1077 	const struct ldc_mode_ops *mops;
1078 	unsigned long dummy1, dummy2, hv_err;
1079 	u8 mss, *mssbuf;
1080 	int err;
1081 
1082 	err = -ENODEV;
1083 	if (!ldom_domaining_enabled)
1084 		goto out_err;
1085 
1086 	err = -EINVAL;
1087 	if (!cfgp)
1088 		goto out_err;
1089 
1090 	switch (cfgp->mode) {
1091 	case LDC_MODE_RAW:
1092 		mops = &raw_ops;
1093 		mss = LDC_PACKET_SIZE;
1094 		break;
1095 
1096 	case LDC_MODE_UNRELIABLE:
1097 		mops = &nonraw_ops;
1098 		mss = LDC_PACKET_SIZE - 8;
1099 		break;
1100 
1101 	case LDC_MODE_STREAM:
1102 		mops = &stream_ops;
1103 		mss = LDC_PACKET_SIZE - 8 - 8;
1104 		break;
1105 
1106 	default:
1107 		goto out_err;
1108 	}
1109 
1110 	if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1111 		goto out_err;
1112 
1113 	hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1114 	err = -ENODEV;
1115 	if (hv_err == HV_ECHANNEL)
1116 		goto out_err;
1117 
1118 	err = -EEXIST;
1119 	if (__ldc_channel_exists(id))
1120 		goto out_err;
1121 
1122 	mssbuf = NULL;
1123 
1124 	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1125 	err = -ENOMEM;
1126 	if (!lp)
1127 		goto out_err;
1128 
1129 	spin_lock_init(&lp->lock);
1130 
1131 	lp->id = id;
1132 
1133 	err = ldc_iommu_init(lp);
1134 	if (err)
1135 		goto out_free_ldc;
1136 
1137 	lp->mops = mops;
1138 	lp->mss = mss;
1139 
1140 	lp->cfg = *cfgp;
1141 	if (!lp->cfg.mtu)
1142 		lp->cfg.mtu = LDC_DEFAULT_MTU;
1143 
1144 	if (lp->cfg.mode == LDC_MODE_STREAM) {
1145 		mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1146 		if (!mssbuf) {
1147 			err = -ENOMEM;
1148 			goto out_free_iommu;
1149 		}
1150 		lp->mssbuf = mssbuf;
1151 	}
1152 
1153 	lp->event_arg = event_arg;
1154 
1155 	/* XXX allow setting via ldc_channel_config to override defaults
1156 	 * XXX or use some formula based upon mtu
1157 	 */
1158 	lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1159 	lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1160 
1161 	err = alloc_queue("TX", lp->tx_num_entries,
1162 			  &lp->tx_base, &lp->tx_ra);
1163 	if (err)
1164 		goto out_free_mssbuf;
1165 
1166 	err = alloc_queue("RX", lp->rx_num_entries,
1167 			  &lp->rx_base, &lp->rx_ra);
1168 	if (err)
1169 		goto out_free_txq;
1170 
1171 	lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1172 
1173 	lp->hs_state = LDC_HS_CLOSED;
1174 	ldc_set_state(lp, LDC_STATE_INIT);
1175 
1176 	INIT_HLIST_NODE(&lp->list);
1177 	hlist_add_head(&lp->list, &ldc_channel_list);
1178 
1179 	INIT_HLIST_HEAD(&lp->mh_list);
1180 
1181 	return lp;
1182 
1183 out_free_txq:
1184 	free_queue(lp->tx_num_entries, lp->tx_base);
1185 
1186 out_free_mssbuf:
1187 	kfree(mssbuf);
1188 
1189 out_free_iommu:
1190 	ldc_iommu_release(lp);
1191 
1192 out_free_ldc:
1193 	kfree(lp);
1194 
1195 out_err:
1196 	return ERR_PTR(err);
1197 }
1198 EXPORT_SYMBOL(ldc_alloc);
1199 
1200 void ldc_free(struct ldc_channel *lp)
1201 {
1202 	if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1203 		free_irq(lp->cfg.rx_irq, lp);
1204 		free_irq(lp->cfg.tx_irq, lp);
1205 	}
1206 
1207 	if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1208 		sun4v_ldc_tx_qconf(lp->id, 0, 0);
1209 		sun4v_ldc_rx_qconf(lp->id, 0, 0);
1210 		lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1211 	}
1212 	if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1213 		free_queue(lp->tx_num_entries, lp->tx_base);
1214 		free_queue(lp->rx_num_entries, lp->rx_base);
1215 		lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1216 	}
1217 
1218 	hlist_del(&lp->list);
1219 
1220 	kfree(lp->mssbuf);
1221 
1222 	ldc_iommu_release(lp);
1223 
1224 	kfree(lp);
1225 }
1226 EXPORT_SYMBOL(ldc_free);
1227 
1228 /* Bind the channel.  This registers the LDC queues with
1229  * the hypervisor and puts the channel into a pseudo-listening
1230  * state.  This does not initiate a handshake, ldc_connect() does
1231  * that.
1232  */
1233 int ldc_bind(struct ldc_channel *lp, const char *name)
1234 {
1235 	unsigned long hv_err, flags;
1236 	int err = -EINVAL;
1237 
1238 	if (!name ||
1239 	    (lp->state != LDC_STATE_INIT))
1240 		return -EINVAL;
1241 
1242 	snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1243 	snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1244 
1245 	err = request_irq(lp->cfg.rx_irq, ldc_rx,
1246 			  IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1247 			  lp->rx_irq_name, lp);
1248 	if (err)
1249 		return err;
1250 
1251 	err = request_irq(lp->cfg.tx_irq, ldc_tx,
1252 			  IRQF_SAMPLE_RANDOM | IRQF_DISABLED,
1253 			  lp->tx_irq_name, lp);
1254 	if (err) {
1255 		free_irq(lp->cfg.rx_irq, lp);
1256 		return err;
1257 	}
1258 
1259 
1260 	spin_lock_irqsave(&lp->lock, flags);
1261 
1262 	enable_irq(lp->cfg.rx_irq);
1263 	enable_irq(lp->cfg.tx_irq);
1264 
1265 	lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1266 
1267 	err = -ENODEV;
1268 	hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1269 	if (hv_err)
1270 		goto out_free_irqs;
1271 
1272 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1273 	if (hv_err)
1274 		goto out_free_irqs;
1275 
1276 	hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1277 	if (hv_err)
1278 		goto out_unmap_tx;
1279 
1280 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1281 	if (hv_err)
1282 		goto out_unmap_tx;
1283 
1284 	lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1285 
1286 	hv_err = sun4v_ldc_tx_get_state(lp->id,
1287 					&lp->tx_head,
1288 					&lp->tx_tail,
1289 					&lp->chan_state);
1290 	err = -EBUSY;
1291 	if (hv_err)
1292 		goto out_unmap_rx;
1293 
1294 	lp->tx_acked = lp->tx_head;
1295 
1296 	lp->hs_state = LDC_HS_OPEN;
1297 	ldc_set_state(lp, LDC_STATE_BOUND);
1298 
1299 	spin_unlock_irqrestore(&lp->lock, flags);
1300 
1301 	return 0;
1302 
1303 out_unmap_rx:
1304 	lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1305 	sun4v_ldc_rx_qconf(lp->id, 0, 0);
1306 
1307 out_unmap_tx:
1308 	sun4v_ldc_tx_qconf(lp->id, 0, 0);
1309 
1310 out_free_irqs:
1311 	lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1312 	free_irq(lp->cfg.tx_irq, lp);
1313 	free_irq(lp->cfg.rx_irq, lp);
1314 
1315 	spin_unlock_irqrestore(&lp->lock, flags);
1316 
1317 	return err;
1318 }
1319 EXPORT_SYMBOL(ldc_bind);
1320 
1321 int ldc_connect(struct ldc_channel *lp)
1322 {
1323 	unsigned long flags;
1324 	int err;
1325 
1326 	if (lp->cfg.mode == LDC_MODE_RAW)
1327 		return -EINVAL;
1328 
1329 	spin_lock_irqsave(&lp->lock, flags);
1330 
1331 	if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1332 	    !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1333 	    lp->hs_state != LDC_HS_OPEN)
1334 		err = -EINVAL;
1335 	else
1336 		err = start_handshake(lp);
1337 
1338 	spin_unlock_irqrestore(&lp->lock, flags);
1339 
1340 	return err;
1341 }
1342 EXPORT_SYMBOL(ldc_connect);
1343 
1344 int ldc_disconnect(struct ldc_channel *lp)
1345 {
1346 	unsigned long hv_err, flags;
1347 	int err;
1348 
1349 	if (lp->cfg.mode == LDC_MODE_RAW)
1350 		return -EINVAL;
1351 
1352 	if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1353 	    !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1354 		return -EINVAL;
1355 
1356 	spin_lock_irqsave(&lp->lock, flags);
1357 
1358 	err = -ENODEV;
1359 	hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1360 	if (hv_err)
1361 		goto out_err;
1362 
1363 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1364 	if (hv_err)
1365 		goto out_err;
1366 
1367 	hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1368 	if (hv_err)
1369 		goto out_err;
1370 
1371 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1372 	if (hv_err)
1373 		goto out_err;
1374 
1375 	ldc_set_state(lp, LDC_STATE_BOUND);
1376 	lp->hs_state = LDC_HS_OPEN;
1377 	lp->flags |= LDC_FLAG_RESET;
1378 
1379 	spin_unlock_irqrestore(&lp->lock, flags);
1380 
1381 	return 0;
1382 
1383 out_err:
1384 	sun4v_ldc_tx_qconf(lp->id, 0, 0);
1385 	sun4v_ldc_rx_qconf(lp->id, 0, 0);
1386 	free_irq(lp->cfg.tx_irq, lp);
1387 	free_irq(lp->cfg.rx_irq, lp);
1388 	lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1389 		       LDC_FLAG_REGISTERED_QUEUES);
1390 	ldc_set_state(lp, LDC_STATE_INIT);
1391 
1392 	spin_unlock_irqrestore(&lp->lock, flags);
1393 
1394 	return err;
1395 }
1396 EXPORT_SYMBOL(ldc_disconnect);
1397 
1398 int ldc_state(struct ldc_channel *lp)
1399 {
1400 	return lp->state;
1401 }
1402 EXPORT_SYMBOL(ldc_state);
1403 
1404 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1405 {
1406 	struct ldc_packet *p;
1407 	unsigned long new_tail;
1408 	int err;
1409 
1410 	if (size > LDC_PACKET_SIZE)
1411 		return -EMSGSIZE;
1412 
1413 	p = data_get_tx_packet(lp, &new_tail);
1414 	if (!p)
1415 		return -EAGAIN;
1416 
1417 	memcpy(p, buf, size);
1418 
1419 	err = send_tx_packet(lp, p, new_tail);
1420 	if (!err)
1421 		err = size;
1422 
1423 	return err;
1424 }
1425 
1426 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1427 {
1428 	struct ldc_packet *p;
1429 	unsigned long hv_err, new;
1430 	int err;
1431 
1432 	if (size < LDC_PACKET_SIZE)
1433 		return -EINVAL;
1434 
1435 	hv_err = sun4v_ldc_rx_get_state(lp->id,
1436 					&lp->rx_head,
1437 					&lp->rx_tail,
1438 					&lp->chan_state);
1439 	if (hv_err)
1440 		return ldc_abort(lp);
1441 
1442 	if (lp->chan_state == LDC_CHANNEL_DOWN ||
1443 	    lp->chan_state == LDC_CHANNEL_RESETTING)
1444 		return -ECONNRESET;
1445 
1446 	if (lp->rx_head == lp->rx_tail)
1447 		return 0;
1448 
1449 	p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1450 	memcpy(buf, p, LDC_PACKET_SIZE);
1451 
1452 	new = rx_advance(lp, lp->rx_head);
1453 	lp->rx_head = new;
1454 
1455 	err = __set_rx_head(lp, new);
1456 	if (err < 0)
1457 		err = -ECONNRESET;
1458 	else
1459 		err = LDC_PACKET_SIZE;
1460 
1461 	return err;
1462 }
1463 
1464 static const struct ldc_mode_ops raw_ops = {
1465 	.write		=	write_raw,
1466 	.read		=	read_raw,
1467 };
1468 
1469 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1470 			unsigned int size)
1471 {
1472 	unsigned long hv_err, tail;
1473 	unsigned int copied;
1474 	u32 seq;
1475 	int err;
1476 
1477 	hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1478 					&lp->chan_state);
1479 	if (unlikely(hv_err))
1480 		return -EBUSY;
1481 
1482 	if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1483 		return ldc_abort(lp);
1484 
1485 	if (!tx_has_space_for(lp, size))
1486 		return -EAGAIN;
1487 
1488 	seq = lp->snd_nxt;
1489 	copied = 0;
1490 	tail = lp->tx_tail;
1491 	while (copied < size) {
1492 		struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1493 		u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1494 			    p->u.u_data :
1495 			    p->u.r.r_data);
1496 		int data_len;
1497 
1498 		p->type = LDC_DATA;
1499 		p->stype = LDC_INFO;
1500 		p->ctrl = 0;
1501 
1502 		data_len = size - copied;
1503 		if (data_len > lp->mss)
1504 			data_len = lp->mss;
1505 
1506 		BUG_ON(data_len > LDC_LEN);
1507 
1508 		p->env = (data_len |
1509 			  (copied == 0 ? LDC_START : 0) |
1510 			  (data_len == size - copied ? LDC_STOP : 0));
1511 
1512 		p->seqid = ++seq;
1513 
1514 		ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1515 		       p->type,
1516 		       p->stype,
1517 		       p->ctrl,
1518 		       p->env,
1519 		       p->seqid);
1520 
1521 		memcpy(data, buf, data_len);
1522 		buf += data_len;
1523 		copied += data_len;
1524 
1525 		tail = tx_advance(lp, tail);
1526 	}
1527 
1528 	err = set_tx_tail(lp, tail);
1529 	if (!err) {
1530 		lp->snd_nxt = seq;
1531 		err = size;
1532 	}
1533 
1534 	return err;
1535 }
1536 
1537 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1538 		      struct ldc_packet *first_frag)
1539 {
1540 	int err;
1541 
1542 	if (first_frag)
1543 		lp->rcv_nxt = first_frag->seqid - 1;
1544 
1545 	err = send_data_nack(lp, p);
1546 	if (err)
1547 		return err;
1548 
1549 	err = __set_rx_head(lp, lp->rx_tail);
1550 	if (err < 0)
1551 		return ldc_abort(lp);
1552 
1553 	return 0;
1554 }
1555 
1556 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1557 {
1558 	if (p->stype & LDC_ACK) {
1559 		int err = process_data_ack(lp, p);
1560 		if (err)
1561 			return err;
1562 	}
1563 	if (p->stype & LDC_NACK)
1564 		return ldc_abort(lp);
1565 
1566 	return 0;
1567 }
1568 
1569 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1570 {
1571 	unsigned long dummy;
1572 	int limit = 1000;
1573 
1574 	ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1575 	       cur_head, lp->rx_head, lp->rx_tail);
1576 	while (limit-- > 0) {
1577 		unsigned long hv_err;
1578 
1579 		hv_err = sun4v_ldc_rx_get_state(lp->id,
1580 						&dummy,
1581 						&lp->rx_tail,
1582 						&lp->chan_state);
1583 		if (hv_err)
1584 			return ldc_abort(lp);
1585 
1586 		if (lp->chan_state == LDC_CHANNEL_DOWN ||
1587 		    lp->chan_state == LDC_CHANNEL_RESETTING)
1588 			return -ECONNRESET;
1589 
1590 		if (cur_head != lp->rx_tail) {
1591 			ldcdbg(DATA, "DATA WAIT DONE "
1592 			       "head[%lx] tail[%lx] chan_state[%lx]\n",
1593 			       dummy, lp->rx_tail, lp->chan_state);
1594 			return 0;
1595 		}
1596 
1597 		udelay(1);
1598 	}
1599 	return -EAGAIN;
1600 }
1601 
1602 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1603 {
1604 	int err = __set_rx_head(lp, head);
1605 
1606 	if (err < 0)
1607 		return ldc_abort(lp);
1608 
1609 	lp->rx_head = head;
1610 	return 0;
1611 }
1612 
1613 static void send_data_ack(struct ldc_channel *lp)
1614 {
1615 	unsigned long new_tail;
1616 	struct ldc_packet *p;
1617 
1618 	p = data_get_tx_packet(lp, &new_tail);
1619 	if (likely(p)) {
1620 		int err;
1621 
1622 		memset(p, 0, sizeof(*p));
1623 		p->type = LDC_DATA;
1624 		p->stype = LDC_ACK;
1625 		p->ctrl = 0;
1626 		p->seqid = lp->snd_nxt + 1;
1627 		p->u.r.ackid = lp->rcv_nxt;
1628 
1629 		err = send_tx_packet(lp, p, new_tail);
1630 		if (!err)
1631 			lp->snd_nxt++;
1632 	}
1633 }
1634 
1635 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1636 {
1637 	struct ldc_packet *first_frag;
1638 	unsigned long hv_err, new;
1639 	int err, copied;
1640 
1641 	hv_err = sun4v_ldc_rx_get_state(lp->id,
1642 					&lp->rx_head,
1643 					&lp->rx_tail,
1644 					&lp->chan_state);
1645 	if (hv_err)
1646 		return ldc_abort(lp);
1647 
1648 	if (lp->chan_state == LDC_CHANNEL_DOWN ||
1649 	    lp->chan_state == LDC_CHANNEL_RESETTING)
1650 		return -ECONNRESET;
1651 
1652 	if (lp->rx_head == lp->rx_tail)
1653 		return 0;
1654 
1655 	first_frag = NULL;
1656 	copied = err = 0;
1657 	new = lp->rx_head;
1658 	while (1) {
1659 		struct ldc_packet *p;
1660 		int pkt_len;
1661 
1662 		BUG_ON(new == lp->rx_tail);
1663 		p = lp->rx_base + (new / LDC_PACKET_SIZE);
1664 
1665 		ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1666 		       "rcv_nxt[%08x]\n",
1667 		       p->type,
1668 		       p->stype,
1669 		       p->ctrl,
1670 		       p->env,
1671 		       p->seqid,
1672 		       p->u.r.ackid,
1673 		       lp->rcv_nxt);
1674 
1675 		if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1676 			err = rx_bad_seq(lp, p, first_frag);
1677 			copied = 0;
1678 			break;
1679 		}
1680 
1681 		if (p->type & LDC_CTRL) {
1682 			err = process_control_frame(lp, p);
1683 			if (err < 0)
1684 				break;
1685 			err = 0;
1686 		}
1687 
1688 		lp->rcv_nxt = p->seqid;
1689 
1690 		if (!(p->type & LDC_DATA)) {
1691 			new = rx_advance(lp, new);
1692 			goto no_data;
1693 		}
1694 		if (p->stype & (LDC_ACK | LDC_NACK)) {
1695 			err = data_ack_nack(lp, p);
1696 			if (err)
1697 				break;
1698 		}
1699 		if (!(p->stype & LDC_INFO)) {
1700 			new = rx_advance(lp, new);
1701 			err = rx_set_head(lp, new);
1702 			if (err)
1703 				break;
1704 			goto no_data;
1705 		}
1706 
1707 		pkt_len = p->env & LDC_LEN;
1708 
1709 		/* Every initial packet starts with the START bit set.
1710 		 *
1711 		 * Singleton packets will have both START+STOP set.
1712 		 *
1713 		 * Fragments will have START set in the first frame, STOP
1714 		 * set in the last frame, and neither bit set in middle
1715 		 * frames of the packet.
1716 		 *
1717 		 * Therefore if we are at the beginning of a packet and
1718 		 * we don't see START, or we are in the middle of a fragmented
1719 		 * packet and do see START, we are unsynchronized and should
1720 		 * flush the RX queue.
1721 		 */
1722 		if ((first_frag == NULL && !(p->env & LDC_START)) ||
1723 		    (first_frag != NULL &&  (p->env & LDC_START))) {
1724 			if (!first_frag)
1725 				new = rx_advance(lp, new);
1726 
1727 			err = rx_set_head(lp, new);
1728 			if (err)
1729 				break;
1730 
1731 			if (!first_frag)
1732 				goto no_data;
1733 		}
1734 		if (!first_frag)
1735 			first_frag = p;
1736 
1737 		if (pkt_len > size - copied) {
1738 			/* User didn't give us a big enough buffer,
1739 			 * what to do?  This is a pretty serious error.
1740 			 *
1741 			 * Since we haven't updated the RX ring head to
1742 			 * consume any of the packets, signal the error
1743 			 * to the user and just leave the RX ring alone.
1744 			 *
1745 			 * This seems the best behavior because this allows
1746 			 * a user of the LDC layer to start with a small
1747 			 * RX buffer for ldc_read() calls and use -EMSGSIZE
1748 			 * as a cue to enlarge it's read buffer.
1749 			 */
1750 			err = -EMSGSIZE;
1751 			break;
1752 		}
1753 
1754 		/* Ok, we are gonna eat this one.  */
1755 		new = rx_advance(lp, new);
1756 
1757 		memcpy(buf,
1758 		       (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1759 			p->u.u_data : p->u.r.r_data), pkt_len);
1760 		buf += pkt_len;
1761 		copied += pkt_len;
1762 
1763 		if (p->env & LDC_STOP)
1764 			break;
1765 
1766 no_data:
1767 		if (new == lp->rx_tail) {
1768 			err = rx_data_wait(lp, new);
1769 			if (err)
1770 				break;
1771 		}
1772 	}
1773 
1774 	if (!err)
1775 		err = rx_set_head(lp, new);
1776 
1777 	if (err && first_frag)
1778 		lp->rcv_nxt = first_frag->seqid - 1;
1779 
1780 	if (!err) {
1781 		err = copied;
1782 		if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1783 			send_data_ack(lp);
1784 	}
1785 
1786 	return err;
1787 }
1788 
1789 static const struct ldc_mode_ops nonraw_ops = {
1790 	.write		=	write_nonraw,
1791 	.read		=	read_nonraw,
1792 };
1793 
1794 static int write_stream(struct ldc_channel *lp, const void *buf,
1795 			unsigned int size)
1796 {
1797 	if (size > lp->cfg.mtu)
1798 		size = lp->cfg.mtu;
1799 	return write_nonraw(lp, buf, size);
1800 }
1801 
1802 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1803 {
1804 	if (!lp->mssbuf_len) {
1805 		int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1806 		if (err < 0)
1807 			return err;
1808 
1809 		lp->mssbuf_len = err;
1810 		lp->mssbuf_off = 0;
1811 	}
1812 
1813 	if (size > lp->mssbuf_len)
1814 		size = lp->mssbuf_len;
1815 	memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1816 
1817 	lp->mssbuf_off += size;
1818 	lp->mssbuf_len -= size;
1819 
1820 	return size;
1821 }
1822 
1823 static const struct ldc_mode_ops stream_ops = {
1824 	.write		=	write_stream,
1825 	.read		=	read_stream,
1826 };
1827 
1828 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1829 {
1830 	unsigned long flags;
1831 	int err;
1832 
1833 	if (!buf)
1834 		return -EINVAL;
1835 
1836 	if (!size)
1837 		return 0;
1838 
1839 	spin_lock_irqsave(&lp->lock, flags);
1840 
1841 	if (lp->hs_state != LDC_HS_COMPLETE)
1842 		err = -ENOTCONN;
1843 	else
1844 		err = lp->mops->write(lp, buf, size);
1845 
1846 	spin_unlock_irqrestore(&lp->lock, flags);
1847 
1848 	return err;
1849 }
1850 EXPORT_SYMBOL(ldc_write);
1851 
1852 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1853 {
1854 	unsigned long flags;
1855 	int err;
1856 
1857 	if (!buf)
1858 		return -EINVAL;
1859 
1860 	if (!size)
1861 		return 0;
1862 
1863 	spin_lock_irqsave(&lp->lock, flags);
1864 
1865 	if (lp->hs_state != LDC_HS_COMPLETE)
1866 		err = -ENOTCONN;
1867 	else
1868 		err = lp->mops->read(lp, buf, size);
1869 
1870 	spin_unlock_irqrestore(&lp->lock, flags);
1871 
1872 	return err;
1873 }
1874 EXPORT_SYMBOL(ldc_read);
1875 
1876 static long arena_alloc(struct ldc_iommu *iommu, unsigned long npages)
1877 {
1878 	struct iommu_arena *arena = &iommu->arena;
1879 	unsigned long n, start, end, limit;
1880 	int pass;
1881 
1882 	limit = arena->limit;
1883 	start = arena->hint;
1884 	pass = 0;
1885 
1886 again:
1887 	n = bitmap_find_next_zero_area(arena->map, limit, start, npages, 0);
1888 	end = n + npages;
1889 	if (unlikely(end >= limit)) {
1890 		if (likely(pass < 1)) {
1891 			limit = start;
1892 			start = 0;
1893 			pass++;
1894 			goto again;
1895 		} else {
1896 			/* Scanned the whole thing, give up. */
1897 			return -1;
1898 		}
1899 	}
1900 	bitmap_set(arena->map, n, npages);
1901 
1902 	arena->hint = end;
1903 
1904 	return n;
1905 }
1906 
1907 #define COOKIE_PGSZ_CODE	0xf000000000000000ULL
1908 #define COOKIE_PGSZ_CODE_SHIFT	60ULL
1909 
1910 static u64 pagesize_code(void)
1911 {
1912 	switch (PAGE_SIZE) {
1913 	default:
1914 	case (8ULL * 1024ULL):
1915 		return 0;
1916 	case (64ULL * 1024ULL):
1917 		return 1;
1918 	case (512ULL * 1024ULL):
1919 		return 2;
1920 	case (4ULL * 1024ULL * 1024ULL):
1921 		return 3;
1922 	case (32ULL * 1024ULL * 1024ULL):
1923 		return 4;
1924 	case (256ULL * 1024ULL * 1024ULL):
1925 		return 5;
1926 	}
1927 }
1928 
1929 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1930 {
1931 	return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1932 		(index << PAGE_SHIFT) |
1933 		page_offset);
1934 }
1935 
1936 static u64 cookie_to_index(u64 cookie, unsigned long *shift)
1937 {
1938 	u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1939 
1940 	cookie &= ~COOKIE_PGSZ_CODE;
1941 
1942 	*shift = szcode * 3;
1943 
1944 	return (cookie >> (13ULL + (szcode * 3ULL)));
1945 }
1946 
1947 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1948 					     unsigned long npages)
1949 {
1950 	long entry;
1951 
1952 	entry = arena_alloc(iommu, npages);
1953 	if (unlikely(entry < 0))
1954 		return NULL;
1955 
1956 	return iommu->page_table + entry;
1957 }
1958 
1959 static u64 perm_to_mte(unsigned int map_perm)
1960 {
1961 	u64 mte_base;
1962 
1963 	mte_base = pagesize_code();
1964 
1965 	if (map_perm & LDC_MAP_SHADOW) {
1966 		if (map_perm & LDC_MAP_R)
1967 			mte_base |= LDC_MTE_COPY_R;
1968 		if (map_perm & LDC_MAP_W)
1969 			mte_base |= LDC_MTE_COPY_W;
1970 	}
1971 	if (map_perm & LDC_MAP_DIRECT) {
1972 		if (map_perm & LDC_MAP_R)
1973 			mte_base |= LDC_MTE_READ;
1974 		if (map_perm & LDC_MAP_W)
1975 			mte_base |= LDC_MTE_WRITE;
1976 		if (map_perm & LDC_MAP_X)
1977 			mte_base |= LDC_MTE_EXEC;
1978 	}
1979 	if (map_perm & LDC_MAP_IO) {
1980 		if (map_perm & LDC_MAP_R)
1981 			mte_base |= LDC_MTE_IOMMU_R;
1982 		if (map_perm & LDC_MAP_W)
1983 			mte_base |= LDC_MTE_IOMMU_W;
1984 	}
1985 
1986 	return mte_base;
1987 }
1988 
1989 static int pages_in_region(unsigned long base, long len)
1990 {
1991 	int count = 0;
1992 
1993 	do {
1994 		unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
1995 
1996 		len -= (new - base);
1997 		base = new;
1998 		count++;
1999 	} while (len > 0);
2000 
2001 	return count;
2002 }
2003 
2004 struct cookie_state {
2005 	struct ldc_mtable_entry		*page_table;
2006 	struct ldc_trans_cookie		*cookies;
2007 	u64				mte_base;
2008 	u64				prev_cookie;
2009 	u32				pte_idx;
2010 	u32				nc;
2011 };
2012 
2013 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2014 			 unsigned long off, unsigned long len)
2015 {
2016 	do {
2017 		unsigned long tlen, new = pa + PAGE_SIZE;
2018 		u64 this_cookie;
2019 
2020 		sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2021 
2022 		tlen = PAGE_SIZE;
2023 		if (off)
2024 			tlen = PAGE_SIZE - off;
2025 		if (tlen > len)
2026 			tlen = len;
2027 
2028 		this_cookie = make_cookie(sp->pte_idx,
2029 					  pagesize_code(), off);
2030 
2031 		off = 0;
2032 
2033 		if (this_cookie == sp->prev_cookie) {
2034 			sp->cookies[sp->nc - 1].cookie_size += tlen;
2035 		} else {
2036 			sp->cookies[sp->nc].cookie_addr = this_cookie;
2037 			sp->cookies[sp->nc].cookie_size = tlen;
2038 			sp->nc++;
2039 		}
2040 		sp->prev_cookie = this_cookie + tlen;
2041 
2042 		sp->pte_idx++;
2043 
2044 		len -= tlen;
2045 		pa = new;
2046 	} while (len > 0);
2047 }
2048 
2049 static int sg_count_one(struct scatterlist *sg)
2050 {
2051 	unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2052 	long len = sg->length;
2053 
2054 	if ((sg->offset | len) & (8UL - 1))
2055 		return -EFAULT;
2056 
2057 	return pages_in_region(base + sg->offset, len);
2058 }
2059 
2060 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2061 {
2062 	int count;
2063 	int i;
2064 
2065 	count = 0;
2066 	for (i = 0; i < num_sg; i++) {
2067 		int err = sg_count_one(sg + i);
2068 		if (err < 0)
2069 			return err;
2070 		count += err;
2071 	}
2072 
2073 	return count;
2074 }
2075 
2076 int ldc_map_sg(struct ldc_channel *lp,
2077 	       struct scatterlist *sg, int num_sg,
2078 	       struct ldc_trans_cookie *cookies, int ncookies,
2079 	       unsigned int map_perm)
2080 {
2081 	unsigned long i, npages, flags;
2082 	struct ldc_mtable_entry *base;
2083 	struct cookie_state state;
2084 	struct ldc_iommu *iommu;
2085 	int err;
2086 
2087 	if (map_perm & ~LDC_MAP_ALL)
2088 		return -EINVAL;
2089 
2090 	err = sg_count_pages(sg, num_sg);
2091 	if (err < 0)
2092 		return err;
2093 
2094 	npages = err;
2095 	if (err > ncookies)
2096 		return -EMSGSIZE;
2097 
2098 	iommu = &lp->iommu;
2099 
2100 	spin_lock_irqsave(&iommu->lock, flags);
2101 	base = alloc_npages(iommu, npages);
2102 	spin_unlock_irqrestore(&iommu->lock, flags);
2103 
2104 	if (!base)
2105 		return -ENOMEM;
2106 
2107 	state.page_table = iommu->page_table;
2108 	state.cookies = cookies;
2109 	state.mte_base = perm_to_mte(map_perm);
2110 	state.prev_cookie = ~(u64)0;
2111 	state.pte_idx = (base - iommu->page_table);
2112 	state.nc = 0;
2113 
2114 	for (i = 0; i < num_sg; i++)
2115 		fill_cookies(&state, page_to_pfn(sg_page(&sg[i])) << PAGE_SHIFT,
2116 			     sg[i].offset, sg[i].length);
2117 
2118 	return state.nc;
2119 }
2120 EXPORT_SYMBOL(ldc_map_sg);
2121 
2122 int ldc_map_single(struct ldc_channel *lp,
2123 		   void *buf, unsigned int len,
2124 		   struct ldc_trans_cookie *cookies, int ncookies,
2125 		   unsigned int map_perm)
2126 {
2127 	unsigned long npages, pa, flags;
2128 	struct ldc_mtable_entry *base;
2129 	struct cookie_state state;
2130 	struct ldc_iommu *iommu;
2131 
2132 	if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2133 		return -EINVAL;
2134 
2135 	pa = __pa(buf);
2136 	if ((pa | len) & (8UL - 1))
2137 		return -EFAULT;
2138 
2139 	npages = pages_in_region(pa, len);
2140 
2141 	iommu = &lp->iommu;
2142 
2143 	spin_lock_irqsave(&iommu->lock, flags);
2144 	base = alloc_npages(iommu, npages);
2145 	spin_unlock_irqrestore(&iommu->lock, flags);
2146 
2147 	if (!base)
2148 		return -ENOMEM;
2149 
2150 	state.page_table = iommu->page_table;
2151 	state.cookies = cookies;
2152 	state.mte_base = perm_to_mte(map_perm);
2153 	state.prev_cookie = ~(u64)0;
2154 	state.pte_idx = (base - iommu->page_table);
2155 	state.nc = 0;
2156 	fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2157 	BUG_ON(state.nc != 1);
2158 
2159 	return state.nc;
2160 }
2161 EXPORT_SYMBOL(ldc_map_single);
2162 
2163 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2164 			u64 cookie, u64 size)
2165 {
2166 	struct iommu_arena *arena = &iommu->arena;
2167 	unsigned long i, shift, index, npages;
2168 	struct ldc_mtable_entry *base;
2169 
2170 	npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2171 	index = cookie_to_index(cookie, &shift);
2172 	base = iommu->page_table + index;
2173 
2174 	BUG_ON(index > arena->limit ||
2175 	       (index + npages) > arena->limit);
2176 
2177 	for (i = 0; i < npages; i++) {
2178 		if (base->cookie)
2179 			sun4v_ldc_revoke(id, cookie + (i << shift),
2180 					 base->cookie);
2181 		base->mte = 0;
2182 		__clear_bit(index + i, arena->map);
2183 	}
2184 }
2185 
2186 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2187 	       int ncookies)
2188 {
2189 	struct ldc_iommu *iommu = &lp->iommu;
2190 	unsigned long flags;
2191 	int i;
2192 
2193 	spin_lock_irqsave(&iommu->lock, flags);
2194 	for (i = 0; i < ncookies; i++) {
2195 		u64 addr = cookies[i].cookie_addr;
2196 		u64 size = cookies[i].cookie_size;
2197 
2198 		free_npages(lp->id, iommu, addr, size);
2199 	}
2200 	spin_unlock_irqrestore(&iommu->lock, flags);
2201 }
2202 EXPORT_SYMBOL(ldc_unmap);
2203 
2204 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2205 	     void *buf, unsigned int len, unsigned long offset,
2206 	     struct ldc_trans_cookie *cookies, int ncookies)
2207 {
2208 	unsigned int orig_len;
2209 	unsigned long ra;
2210 	int i;
2211 
2212 	if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2213 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2214 		       lp->id, copy_dir);
2215 		return -EINVAL;
2216 	}
2217 
2218 	ra = __pa(buf);
2219 	if ((ra | len | offset) & (8UL - 1)) {
2220 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2221 		       "ra[%lx] len[%x] offset[%lx]\n",
2222 		       lp->id, ra, len, offset);
2223 		return -EFAULT;
2224 	}
2225 
2226 	if (lp->hs_state != LDC_HS_COMPLETE ||
2227 	    (lp->flags & LDC_FLAG_RESET)) {
2228 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2229 		       "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2230 		return -ECONNRESET;
2231 	}
2232 
2233 	orig_len = len;
2234 	for (i = 0; i < ncookies; i++) {
2235 		unsigned long cookie_raddr = cookies[i].cookie_addr;
2236 		unsigned long this_len = cookies[i].cookie_size;
2237 		unsigned long actual_len;
2238 
2239 		if (unlikely(offset)) {
2240 			unsigned long this_off = offset;
2241 
2242 			if (this_off > this_len)
2243 				this_off = this_len;
2244 
2245 			offset -= this_off;
2246 			this_len -= this_off;
2247 			if (!this_len)
2248 				continue;
2249 			cookie_raddr += this_off;
2250 		}
2251 
2252 		if (this_len > len)
2253 			this_len = len;
2254 
2255 		while (1) {
2256 			unsigned long hv_err;
2257 
2258 			hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2259 						cookie_raddr, ra,
2260 						this_len, &actual_len);
2261 			if (unlikely(hv_err)) {
2262 				printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2263 				       "HV error %lu\n",
2264 				       lp->id, hv_err);
2265 				if (lp->hs_state != LDC_HS_COMPLETE ||
2266 				    (lp->flags & LDC_FLAG_RESET))
2267 					return -ECONNRESET;
2268 				else
2269 					return -EFAULT;
2270 			}
2271 
2272 			cookie_raddr += actual_len;
2273 			ra += actual_len;
2274 			len -= actual_len;
2275 			if (actual_len == this_len)
2276 				break;
2277 
2278 			this_len -= actual_len;
2279 		}
2280 
2281 		if (!len)
2282 			break;
2283 	}
2284 
2285 	/* It is caller policy what to do about short copies.
2286 	 * For example, a networking driver can declare the
2287 	 * packet a runt and drop it.
2288 	 */
2289 
2290 	return orig_len - len;
2291 }
2292 EXPORT_SYMBOL(ldc_copy);
2293 
2294 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2295 			  struct ldc_trans_cookie *cookies, int *ncookies,
2296 			  unsigned int map_perm)
2297 {
2298 	void *buf;
2299 	int err;
2300 
2301 	if (len & (8UL - 1))
2302 		return ERR_PTR(-EINVAL);
2303 
2304 	buf = kzalloc(len, GFP_KERNEL);
2305 	if (!buf)
2306 		return ERR_PTR(-ENOMEM);
2307 
2308 	err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2309 	if (err < 0) {
2310 		kfree(buf);
2311 		return ERR_PTR(err);
2312 	}
2313 	*ncookies = err;
2314 
2315 	return buf;
2316 }
2317 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2318 
2319 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2320 			struct ldc_trans_cookie *cookies, int ncookies)
2321 {
2322 	ldc_unmap(lp, cookies, ncookies);
2323 	kfree(buf);
2324 }
2325 EXPORT_SYMBOL(ldc_free_exp_dring);
2326 
2327 static int __init ldc_init(void)
2328 {
2329 	unsigned long major, minor;
2330 	struct mdesc_handle *hp;
2331 	const u64 *v;
2332 	int err;
2333 	u64 mp;
2334 
2335 	hp = mdesc_grab();
2336 	if (!hp)
2337 		return -ENODEV;
2338 
2339 	mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2340 	err = -ENODEV;
2341 	if (mp == MDESC_NODE_NULL)
2342 		goto out;
2343 
2344 	v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2345 	if (!v)
2346 		goto out;
2347 
2348 	major = 1;
2349 	minor = 0;
2350 	if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2351 		printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2352 		goto out;
2353 	}
2354 
2355 	printk(KERN_INFO "%s", version);
2356 
2357 	if (!*v) {
2358 		printk(KERN_INFO PFX "Domaining disabled.\n");
2359 		goto out;
2360 	}
2361 	ldom_domaining_enabled = 1;
2362 	err = 0;
2363 
2364 out:
2365 	mdesc_release(hp);
2366 	return err;
2367 }
2368 
2369 core_initcall(ldc_init);
2370