xref: /openbmc/linux/arch/sparc/kernel/ldc.c (revision 8730046c)
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 #include <linux/iommu-common.h>
19 
20 #include <asm/hypervisor.h>
21 #include <asm/iommu.h>
22 #include <asm/page.h>
23 #include <asm/ldc.h>
24 #include <asm/mdesc.h>
25 
26 #define DRV_MODULE_NAME		"ldc"
27 #define PFX DRV_MODULE_NAME	": "
28 #define DRV_MODULE_VERSION	"1.1"
29 #define DRV_MODULE_RELDATE	"July 22, 2008"
30 
31 #define COOKIE_PGSZ_CODE	0xf000000000000000ULL
32 #define COOKIE_PGSZ_CODE_SHIFT	60ULL
33 
34 
35 static char version[] =
36 	DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
37 #define LDC_PACKET_SIZE		64
38 
39 /* Packet header layout for unreliable and reliable mode frames.
40  * When in RAW mode, packets are simply straight 64-byte payloads
41  * with no headers.
42  */
43 struct ldc_packet {
44 	u8			type;
45 #define LDC_CTRL		0x01
46 #define LDC_DATA		0x02
47 #define LDC_ERR			0x10
48 
49 	u8			stype;
50 #define LDC_INFO		0x01
51 #define LDC_ACK			0x02
52 #define LDC_NACK		0x04
53 
54 	u8			ctrl;
55 #define LDC_VERS		0x01 /* Link Version		*/
56 #define LDC_RTS			0x02 /* Request To Send		*/
57 #define LDC_RTR			0x03 /* Ready To Receive	*/
58 #define LDC_RDX			0x04 /* Ready for Data eXchange	*/
59 #define LDC_CTRL_MSK		0x0f
60 
61 	u8			env;
62 #define LDC_LEN			0x3f
63 #define LDC_FRAG_MASK		0xc0
64 #define LDC_START		0x40
65 #define LDC_STOP		0x80
66 
67 	u32			seqid;
68 
69 	union {
70 		u8		u_data[LDC_PACKET_SIZE - 8];
71 		struct {
72 			u32	pad;
73 			u32	ackid;
74 			u8	r_data[LDC_PACKET_SIZE - 8 - 8];
75 		} r;
76 	} u;
77 };
78 
79 struct ldc_version {
80 	u16 major;
81 	u16 minor;
82 };
83 
84 /* Ordered from largest major to lowest.  */
85 static struct ldc_version ver_arr[] = {
86 	{ .major = 1, .minor = 0 },
87 };
88 
89 #define LDC_DEFAULT_MTU			(4 * LDC_PACKET_SIZE)
90 #define LDC_DEFAULT_NUM_ENTRIES		(PAGE_SIZE / LDC_PACKET_SIZE)
91 
92 struct ldc_channel;
93 
94 struct ldc_mode_ops {
95 	int (*write)(struct ldc_channel *, const void *, unsigned int);
96 	int (*read)(struct ldc_channel *, void *, unsigned int);
97 };
98 
99 static const struct ldc_mode_ops raw_ops;
100 static const struct ldc_mode_ops nonraw_ops;
101 static const struct ldc_mode_ops stream_ops;
102 
103 int ldom_domaining_enabled;
104 
105 struct ldc_iommu {
106 	/* Protects ldc_unmap.  */
107 	spinlock_t			lock;
108 	struct ldc_mtable_entry		*page_table;
109 	struct iommu_map_table		iommu_map_table;
110 };
111 
112 struct ldc_channel {
113 	/* Protects all operations that depend upon channel state.  */
114 	spinlock_t			lock;
115 
116 	unsigned long			id;
117 
118 	u8				*mssbuf;
119 	u32				mssbuf_len;
120 	u32				mssbuf_off;
121 
122 	struct ldc_packet		*tx_base;
123 	unsigned long			tx_head;
124 	unsigned long			tx_tail;
125 	unsigned long			tx_num_entries;
126 	unsigned long			tx_ra;
127 
128 	unsigned long			tx_acked;
129 
130 	struct ldc_packet		*rx_base;
131 	unsigned long			rx_head;
132 	unsigned long			rx_tail;
133 	unsigned long			rx_num_entries;
134 	unsigned long			rx_ra;
135 
136 	u32				rcv_nxt;
137 	u32				snd_nxt;
138 
139 	unsigned long			chan_state;
140 
141 	struct ldc_channel_config	cfg;
142 	void				*event_arg;
143 
144 	const struct ldc_mode_ops	*mops;
145 
146 	struct ldc_iommu		iommu;
147 
148 	struct ldc_version		ver;
149 
150 	u8				hs_state;
151 #define LDC_HS_CLOSED			0x00
152 #define LDC_HS_OPEN			0x01
153 #define LDC_HS_GOTVERS			0x02
154 #define LDC_HS_SENTRTR			0x03
155 #define LDC_HS_GOTRTR			0x04
156 #define LDC_HS_COMPLETE			0x10
157 
158 	u8				flags;
159 #define LDC_FLAG_ALLOCED_QUEUES		0x01
160 #define LDC_FLAG_REGISTERED_QUEUES	0x02
161 #define LDC_FLAG_REGISTERED_IRQS	0x04
162 #define LDC_FLAG_RESET			0x10
163 
164 	u8				mss;
165 	u8				state;
166 
167 #define LDC_IRQ_NAME_MAX		32
168 	char				rx_irq_name[LDC_IRQ_NAME_MAX];
169 	char				tx_irq_name[LDC_IRQ_NAME_MAX];
170 
171 	struct hlist_head		mh_list;
172 
173 	struct hlist_node		list;
174 };
175 
176 #define ldcdbg(TYPE, f, a...) \
177 do {	if (lp->cfg.debug & LDC_DEBUG_##TYPE) \
178 		printk(KERN_INFO PFX "ID[%lu] " f, lp->id, ## a); \
179 } while (0)
180 
181 static const char *state_to_str(u8 state)
182 {
183 	switch (state) {
184 	case LDC_STATE_INVALID:
185 		return "INVALID";
186 	case LDC_STATE_INIT:
187 		return "INIT";
188 	case LDC_STATE_BOUND:
189 		return "BOUND";
190 	case LDC_STATE_READY:
191 		return "READY";
192 	case LDC_STATE_CONNECTED:
193 		return "CONNECTED";
194 	default:
195 		return "<UNKNOWN>";
196 	}
197 }
198 
199 static void ldc_set_state(struct ldc_channel *lp, u8 state)
200 {
201 	ldcdbg(STATE, "STATE (%s) --> (%s)\n",
202 	       state_to_str(lp->state),
203 	       state_to_str(state));
204 
205 	lp->state = state;
206 }
207 
208 static unsigned long __advance(unsigned long off, unsigned long num_entries)
209 {
210 	off += LDC_PACKET_SIZE;
211 	if (off == (num_entries * LDC_PACKET_SIZE))
212 		off = 0;
213 
214 	return off;
215 }
216 
217 static unsigned long rx_advance(struct ldc_channel *lp, unsigned long off)
218 {
219 	return __advance(off, lp->rx_num_entries);
220 }
221 
222 static unsigned long tx_advance(struct ldc_channel *lp, unsigned long off)
223 {
224 	return __advance(off, lp->tx_num_entries);
225 }
226 
227 static struct ldc_packet *handshake_get_tx_packet(struct ldc_channel *lp,
228 						  unsigned long *new_tail)
229 {
230 	struct ldc_packet *p;
231 	unsigned long t;
232 
233 	t = tx_advance(lp, lp->tx_tail);
234 	if (t == lp->tx_head)
235 		return NULL;
236 
237 	*new_tail = t;
238 
239 	p = lp->tx_base;
240 	return p + (lp->tx_tail / LDC_PACKET_SIZE);
241 }
242 
243 /* When we are in reliable or stream mode, have to track the next packet
244  * we haven't gotten an ACK for in the TX queue using tx_acked.  We have
245  * to be careful not to stomp over the queue past that point.  During
246  * the handshake, we don't have TX data packets pending in the queue
247  * and that's why handshake_get_tx_packet() need not be mindful of
248  * lp->tx_acked.
249  */
250 static unsigned long head_for_data(struct ldc_channel *lp)
251 {
252 	if (lp->cfg.mode == LDC_MODE_STREAM)
253 		return lp->tx_acked;
254 	return lp->tx_head;
255 }
256 
257 static int tx_has_space_for(struct ldc_channel *lp, unsigned int size)
258 {
259 	unsigned long limit, tail, new_tail, diff;
260 	unsigned int mss;
261 
262 	limit = head_for_data(lp);
263 	tail = lp->tx_tail;
264 	new_tail = tx_advance(lp, tail);
265 	if (new_tail == limit)
266 		return 0;
267 
268 	if (limit > new_tail)
269 		diff = limit - new_tail;
270 	else
271 		diff = (limit +
272 			((lp->tx_num_entries * LDC_PACKET_SIZE) - new_tail));
273 	diff /= LDC_PACKET_SIZE;
274 	mss = lp->mss;
275 
276 	if (diff * mss < size)
277 		return 0;
278 
279 	return 1;
280 }
281 
282 static struct ldc_packet *data_get_tx_packet(struct ldc_channel *lp,
283 					     unsigned long *new_tail)
284 {
285 	struct ldc_packet *p;
286 	unsigned long h, t;
287 
288 	h = head_for_data(lp);
289 	t = tx_advance(lp, lp->tx_tail);
290 	if (t == h)
291 		return NULL;
292 
293 	*new_tail = t;
294 
295 	p = lp->tx_base;
296 	return p + (lp->tx_tail / LDC_PACKET_SIZE);
297 }
298 
299 static int set_tx_tail(struct ldc_channel *lp, unsigned long tail)
300 {
301 	unsigned long orig_tail = lp->tx_tail;
302 	int limit = 1000;
303 
304 	lp->tx_tail = tail;
305 	while (limit-- > 0) {
306 		unsigned long err;
307 
308 		err = sun4v_ldc_tx_set_qtail(lp->id, tail);
309 		if (!err)
310 			return 0;
311 
312 		if (err != HV_EWOULDBLOCK) {
313 			lp->tx_tail = orig_tail;
314 			return -EINVAL;
315 		}
316 		udelay(1);
317 	}
318 
319 	lp->tx_tail = orig_tail;
320 	return -EBUSY;
321 }
322 
323 /* This just updates the head value in the hypervisor using
324  * a polling loop with a timeout.  The caller takes care of
325  * upating software state representing the head change, if any.
326  */
327 static int __set_rx_head(struct ldc_channel *lp, unsigned long head)
328 {
329 	int limit = 1000;
330 
331 	while (limit-- > 0) {
332 		unsigned long err;
333 
334 		err = sun4v_ldc_rx_set_qhead(lp->id, head);
335 		if (!err)
336 			return 0;
337 
338 		if (err != HV_EWOULDBLOCK)
339 			return -EINVAL;
340 
341 		udelay(1);
342 	}
343 
344 	return -EBUSY;
345 }
346 
347 static int send_tx_packet(struct ldc_channel *lp,
348 			  struct ldc_packet *p,
349 			  unsigned long new_tail)
350 {
351 	BUG_ON(p != (lp->tx_base + (lp->tx_tail / LDC_PACKET_SIZE)));
352 
353 	return set_tx_tail(lp, new_tail);
354 }
355 
356 static struct ldc_packet *handshake_compose_ctrl(struct ldc_channel *lp,
357 						 u8 stype, u8 ctrl,
358 						 void *data, int dlen,
359 						 unsigned long *new_tail)
360 {
361 	struct ldc_packet *p = handshake_get_tx_packet(lp, new_tail);
362 
363 	if (p) {
364 		memset(p, 0, sizeof(*p));
365 		p->type = LDC_CTRL;
366 		p->stype = stype;
367 		p->ctrl = ctrl;
368 		if (data)
369 			memcpy(p->u.u_data, data, dlen);
370 	}
371 	return p;
372 }
373 
374 static int start_handshake(struct ldc_channel *lp)
375 {
376 	struct ldc_packet *p;
377 	struct ldc_version *ver;
378 	unsigned long new_tail;
379 
380 	ver = &ver_arr[0];
381 
382 	ldcdbg(HS, "SEND VER INFO maj[%u] min[%u]\n",
383 	       ver->major, ver->minor);
384 
385 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
386 				   ver, sizeof(*ver), &new_tail);
387 	if (p) {
388 		int err = send_tx_packet(lp, p, new_tail);
389 		if (!err)
390 			lp->flags &= ~LDC_FLAG_RESET;
391 		return err;
392 	}
393 	return -EBUSY;
394 }
395 
396 static int send_version_nack(struct ldc_channel *lp,
397 			     u16 major, u16 minor)
398 {
399 	struct ldc_packet *p;
400 	struct ldc_version ver;
401 	unsigned long new_tail;
402 
403 	ver.major = major;
404 	ver.minor = minor;
405 
406 	p = handshake_compose_ctrl(lp, LDC_NACK, LDC_VERS,
407 				   &ver, sizeof(ver), &new_tail);
408 	if (p) {
409 		ldcdbg(HS, "SEND VER NACK maj[%u] min[%u]\n",
410 		       ver.major, ver.minor);
411 
412 		return send_tx_packet(lp, p, new_tail);
413 	}
414 	return -EBUSY;
415 }
416 
417 static int send_version_ack(struct ldc_channel *lp,
418 			    struct ldc_version *vp)
419 {
420 	struct ldc_packet *p;
421 	unsigned long new_tail;
422 
423 	p = handshake_compose_ctrl(lp, LDC_ACK, LDC_VERS,
424 				   vp, sizeof(*vp), &new_tail);
425 	if (p) {
426 		ldcdbg(HS, "SEND VER ACK maj[%u] min[%u]\n",
427 		       vp->major, vp->minor);
428 
429 		return send_tx_packet(lp, p, new_tail);
430 	}
431 	return -EBUSY;
432 }
433 
434 static int send_rts(struct ldc_channel *lp)
435 {
436 	struct ldc_packet *p;
437 	unsigned long new_tail;
438 
439 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTS, NULL, 0,
440 				   &new_tail);
441 	if (p) {
442 		p->env = lp->cfg.mode;
443 		p->seqid = 0;
444 		lp->rcv_nxt = 0;
445 
446 		ldcdbg(HS, "SEND RTS env[0x%x] seqid[0x%x]\n",
447 		       p->env, p->seqid);
448 
449 		return send_tx_packet(lp, p, new_tail);
450 	}
451 	return -EBUSY;
452 }
453 
454 static int send_rtr(struct ldc_channel *lp)
455 {
456 	struct ldc_packet *p;
457 	unsigned long new_tail;
458 
459 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RTR, NULL, 0,
460 				   &new_tail);
461 	if (p) {
462 		p->env = lp->cfg.mode;
463 		p->seqid = 0;
464 
465 		ldcdbg(HS, "SEND RTR env[0x%x] seqid[0x%x]\n",
466 		       p->env, p->seqid);
467 
468 		return send_tx_packet(lp, p, new_tail);
469 	}
470 	return -EBUSY;
471 }
472 
473 static int send_rdx(struct ldc_channel *lp)
474 {
475 	struct ldc_packet *p;
476 	unsigned long new_tail;
477 
478 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_RDX, NULL, 0,
479 				   &new_tail);
480 	if (p) {
481 		p->env = 0;
482 		p->seqid = ++lp->snd_nxt;
483 		p->u.r.ackid = lp->rcv_nxt;
484 
485 		ldcdbg(HS, "SEND RDX env[0x%x] seqid[0x%x] ackid[0x%x]\n",
486 		       p->env, p->seqid, p->u.r.ackid);
487 
488 		return send_tx_packet(lp, p, new_tail);
489 	}
490 	return -EBUSY;
491 }
492 
493 static int send_data_nack(struct ldc_channel *lp, struct ldc_packet *data_pkt)
494 {
495 	struct ldc_packet *p;
496 	unsigned long new_tail;
497 	int err;
498 
499 	p = data_get_tx_packet(lp, &new_tail);
500 	if (!p)
501 		return -EBUSY;
502 	memset(p, 0, sizeof(*p));
503 	p->type = data_pkt->type;
504 	p->stype = LDC_NACK;
505 	p->ctrl = data_pkt->ctrl & LDC_CTRL_MSK;
506 	p->seqid = lp->snd_nxt + 1;
507 	p->u.r.ackid = lp->rcv_nxt;
508 
509 	ldcdbg(HS, "SEND DATA NACK type[0x%x] ctl[0x%x] seq[0x%x] ack[0x%x]\n",
510 	       p->type, p->ctrl, p->seqid, p->u.r.ackid);
511 
512 	err = send_tx_packet(lp, p, new_tail);
513 	if (!err)
514 		lp->snd_nxt++;
515 
516 	return err;
517 }
518 
519 static int ldc_abort(struct ldc_channel *lp)
520 {
521 	unsigned long hv_err;
522 
523 	ldcdbg(STATE, "ABORT\n");
524 
525 	/* We report but do not act upon the hypervisor errors because
526 	 * there really isn't much we can do if they fail at this point.
527 	 */
528 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
529 	if (hv_err)
530 		printk(KERN_ERR PFX "ldc_abort: "
531 		       "sun4v_ldc_tx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
532 		       lp->id, lp->tx_ra, lp->tx_num_entries, hv_err);
533 
534 	hv_err = sun4v_ldc_tx_get_state(lp->id,
535 					&lp->tx_head,
536 					&lp->tx_tail,
537 					&lp->chan_state);
538 	if (hv_err)
539 		printk(KERN_ERR PFX "ldc_abort: "
540 		       "sun4v_ldc_tx_get_state(%lx,...) failed, err=%lu\n",
541 		       lp->id, hv_err);
542 
543 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
544 	if (hv_err)
545 		printk(KERN_ERR PFX "ldc_abort: "
546 		       "sun4v_ldc_rx_qconf(%lx,%lx,%lx) failed, err=%lu\n",
547 		       lp->id, lp->rx_ra, lp->rx_num_entries, hv_err);
548 
549 	/* Refetch the RX queue state as well, because we could be invoked
550 	 * here in the queue processing context.
551 	 */
552 	hv_err = sun4v_ldc_rx_get_state(lp->id,
553 					&lp->rx_head,
554 					&lp->rx_tail,
555 					&lp->chan_state);
556 	if (hv_err)
557 		printk(KERN_ERR PFX "ldc_abort: "
558 		       "sun4v_ldc_rx_get_state(%lx,...) failed, err=%lu\n",
559 		       lp->id, hv_err);
560 
561 	return -ECONNRESET;
562 }
563 
564 static struct ldc_version *find_by_major(u16 major)
565 {
566 	struct ldc_version *ret = NULL;
567 	int i;
568 
569 	for (i = 0; i < ARRAY_SIZE(ver_arr); i++) {
570 		struct ldc_version *v = &ver_arr[i];
571 		if (v->major <= major) {
572 			ret = v;
573 			break;
574 		}
575 	}
576 	return ret;
577 }
578 
579 static int process_ver_info(struct ldc_channel *lp, struct ldc_version *vp)
580 {
581 	struct ldc_version *vap;
582 	int err;
583 
584 	ldcdbg(HS, "GOT VERSION INFO major[%x] minor[%x]\n",
585 	       vp->major, vp->minor);
586 
587 	if (lp->hs_state == LDC_HS_GOTVERS) {
588 		lp->hs_state = LDC_HS_OPEN;
589 		memset(&lp->ver, 0, sizeof(lp->ver));
590 	}
591 
592 	vap = find_by_major(vp->major);
593 	if (!vap) {
594 		err = send_version_nack(lp, 0, 0);
595 	} else if (vap->major != vp->major) {
596 		err = send_version_nack(lp, vap->major, vap->minor);
597 	} else {
598 		struct ldc_version ver = *vp;
599 		if (ver.minor > vap->minor)
600 			ver.minor = vap->minor;
601 		err = send_version_ack(lp, &ver);
602 		if (!err) {
603 			lp->ver = ver;
604 			lp->hs_state = LDC_HS_GOTVERS;
605 		}
606 	}
607 	if (err)
608 		return ldc_abort(lp);
609 
610 	return 0;
611 }
612 
613 static int process_ver_ack(struct ldc_channel *lp, struct ldc_version *vp)
614 {
615 	ldcdbg(HS, "GOT VERSION ACK major[%x] minor[%x]\n",
616 	       vp->major, vp->minor);
617 
618 	if (lp->hs_state == LDC_HS_GOTVERS) {
619 		if (lp->ver.major != vp->major ||
620 		    lp->ver.minor != vp->minor)
621 			return ldc_abort(lp);
622 	} else {
623 		lp->ver = *vp;
624 		lp->hs_state = LDC_HS_GOTVERS;
625 	}
626 	if (send_rts(lp))
627 		return ldc_abort(lp);
628 	return 0;
629 }
630 
631 static int process_ver_nack(struct ldc_channel *lp, struct ldc_version *vp)
632 {
633 	struct ldc_version *vap;
634 	struct ldc_packet *p;
635 	unsigned long new_tail;
636 
637 	if (vp->major == 0 && vp->minor == 0)
638 		return ldc_abort(lp);
639 
640 	vap = find_by_major(vp->major);
641 	if (!vap)
642 		return ldc_abort(lp);
643 
644 	p = handshake_compose_ctrl(lp, LDC_INFO, LDC_VERS,
645 					   vap, sizeof(*vap),
646 					   &new_tail);
647 	if (!p)
648 		return ldc_abort(lp);
649 
650 	return send_tx_packet(lp, p, new_tail);
651 }
652 
653 static int process_version(struct ldc_channel *lp,
654 			   struct ldc_packet *p)
655 {
656 	struct ldc_version *vp;
657 
658 	vp = (struct ldc_version *) p->u.u_data;
659 
660 	switch (p->stype) {
661 	case LDC_INFO:
662 		return process_ver_info(lp, vp);
663 
664 	case LDC_ACK:
665 		return process_ver_ack(lp, vp);
666 
667 	case LDC_NACK:
668 		return process_ver_nack(lp, vp);
669 
670 	default:
671 		return ldc_abort(lp);
672 	}
673 }
674 
675 static int process_rts(struct ldc_channel *lp,
676 		       struct ldc_packet *p)
677 {
678 	ldcdbg(HS, "GOT RTS stype[%x] seqid[%x] env[%x]\n",
679 	       p->stype, p->seqid, p->env);
680 
681 	if (p->stype     != LDC_INFO	   ||
682 	    lp->hs_state != LDC_HS_GOTVERS ||
683 	    p->env       != lp->cfg.mode)
684 		return ldc_abort(lp);
685 
686 	lp->snd_nxt = p->seqid;
687 	lp->rcv_nxt = p->seqid;
688 	lp->hs_state = LDC_HS_SENTRTR;
689 	if (send_rtr(lp))
690 		return ldc_abort(lp);
691 
692 	return 0;
693 }
694 
695 static int process_rtr(struct ldc_channel *lp,
696 		       struct ldc_packet *p)
697 {
698 	ldcdbg(HS, "GOT RTR stype[%x] seqid[%x] env[%x]\n",
699 	       p->stype, p->seqid, p->env);
700 
701 	if (p->stype     != LDC_INFO ||
702 	    p->env       != lp->cfg.mode)
703 		return ldc_abort(lp);
704 
705 	lp->snd_nxt = p->seqid;
706 	lp->hs_state = LDC_HS_COMPLETE;
707 	ldc_set_state(lp, LDC_STATE_CONNECTED);
708 	send_rdx(lp);
709 
710 	return LDC_EVENT_UP;
711 }
712 
713 static int rx_seq_ok(struct ldc_channel *lp, u32 seqid)
714 {
715 	return lp->rcv_nxt + 1 == seqid;
716 }
717 
718 static int process_rdx(struct ldc_channel *lp,
719 		       struct ldc_packet *p)
720 {
721 	ldcdbg(HS, "GOT RDX stype[%x] seqid[%x] env[%x] ackid[%x]\n",
722 	       p->stype, p->seqid, p->env, p->u.r.ackid);
723 
724 	if (p->stype != LDC_INFO ||
725 	    !(rx_seq_ok(lp, p->seqid)))
726 		return ldc_abort(lp);
727 
728 	lp->rcv_nxt = p->seqid;
729 
730 	lp->hs_state = LDC_HS_COMPLETE;
731 	ldc_set_state(lp, LDC_STATE_CONNECTED);
732 
733 	return LDC_EVENT_UP;
734 }
735 
736 static int process_control_frame(struct ldc_channel *lp,
737 				 struct ldc_packet *p)
738 {
739 	switch (p->ctrl) {
740 	case LDC_VERS:
741 		return process_version(lp, p);
742 
743 	case LDC_RTS:
744 		return process_rts(lp, p);
745 
746 	case LDC_RTR:
747 		return process_rtr(lp, p);
748 
749 	case LDC_RDX:
750 		return process_rdx(lp, p);
751 
752 	default:
753 		return ldc_abort(lp);
754 	}
755 }
756 
757 static int process_error_frame(struct ldc_channel *lp,
758 			       struct ldc_packet *p)
759 {
760 	return ldc_abort(lp);
761 }
762 
763 static int process_data_ack(struct ldc_channel *lp,
764 			    struct ldc_packet *ack)
765 {
766 	unsigned long head = lp->tx_acked;
767 	u32 ackid = ack->u.r.ackid;
768 
769 	while (1) {
770 		struct ldc_packet *p = lp->tx_base + (head / LDC_PACKET_SIZE);
771 
772 		head = tx_advance(lp, head);
773 
774 		if (p->seqid == ackid) {
775 			lp->tx_acked = head;
776 			return 0;
777 		}
778 		if (head == lp->tx_tail)
779 			return ldc_abort(lp);
780 	}
781 
782 	return 0;
783 }
784 
785 static void send_events(struct ldc_channel *lp, unsigned int event_mask)
786 {
787 	if (event_mask & LDC_EVENT_RESET)
788 		lp->cfg.event(lp->event_arg, LDC_EVENT_RESET);
789 	if (event_mask & LDC_EVENT_UP)
790 		lp->cfg.event(lp->event_arg, LDC_EVENT_UP);
791 	if (event_mask & LDC_EVENT_DATA_READY)
792 		lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
793 }
794 
795 static irqreturn_t ldc_rx(int irq, void *dev_id)
796 {
797 	struct ldc_channel *lp = dev_id;
798 	unsigned long orig_state, flags;
799 	unsigned int event_mask;
800 
801 	spin_lock_irqsave(&lp->lock, flags);
802 
803 	orig_state = lp->chan_state;
804 
805 	/* We should probably check for hypervisor errors here and
806 	 * reset the LDC channel if we get one.
807 	 */
808 	sun4v_ldc_rx_get_state(lp->id,
809 			       &lp->rx_head,
810 			       &lp->rx_tail,
811 			       &lp->chan_state);
812 
813 	ldcdbg(RX, "RX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
814 	       orig_state, lp->chan_state, lp->rx_head, lp->rx_tail);
815 
816 	event_mask = 0;
817 
818 	if (lp->cfg.mode == LDC_MODE_RAW &&
819 	    lp->chan_state == LDC_CHANNEL_UP) {
820 		lp->hs_state = LDC_HS_COMPLETE;
821 		ldc_set_state(lp, LDC_STATE_CONNECTED);
822 
823 		event_mask |= LDC_EVENT_UP;
824 
825 		orig_state = lp->chan_state;
826 	}
827 
828 	/* If we are in reset state, flush the RX queue and ignore
829 	 * everything.
830 	 */
831 	if (lp->flags & LDC_FLAG_RESET) {
832 		(void) __set_rx_head(lp, lp->rx_tail);
833 		goto out;
834 	}
835 
836 	/* Once we finish the handshake, we let the ldc_read()
837 	 * paths do all of the control frame and state management.
838 	 * Just trigger the callback.
839 	 */
840 	if (lp->hs_state == LDC_HS_COMPLETE) {
841 handshake_complete:
842 		if (lp->chan_state != orig_state) {
843 			unsigned int event = LDC_EVENT_RESET;
844 
845 			if (lp->chan_state == LDC_CHANNEL_UP)
846 				event = LDC_EVENT_UP;
847 
848 			event_mask |= event;
849 		}
850 		if (lp->rx_head != lp->rx_tail)
851 			event_mask |= LDC_EVENT_DATA_READY;
852 
853 		goto out;
854 	}
855 
856 	if (lp->chan_state != orig_state)
857 		goto out;
858 
859 	while (lp->rx_head != lp->rx_tail) {
860 		struct ldc_packet *p;
861 		unsigned long new;
862 		int err;
863 
864 		p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
865 
866 		switch (p->type) {
867 		case LDC_CTRL:
868 			err = process_control_frame(lp, p);
869 			if (err > 0)
870 				event_mask |= err;
871 			break;
872 
873 		case LDC_DATA:
874 			event_mask |= LDC_EVENT_DATA_READY;
875 			err = 0;
876 			break;
877 
878 		case LDC_ERR:
879 			err = process_error_frame(lp, p);
880 			break;
881 
882 		default:
883 			err = ldc_abort(lp);
884 			break;
885 		}
886 
887 		if (err < 0)
888 			break;
889 
890 		new = lp->rx_head;
891 		new += LDC_PACKET_SIZE;
892 		if (new == (lp->rx_num_entries * LDC_PACKET_SIZE))
893 			new = 0;
894 		lp->rx_head = new;
895 
896 		err = __set_rx_head(lp, new);
897 		if (err < 0) {
898 			(void) ldc_abort(lp);
899 			break;
900 		}
901 		if (lp->hs_state == LDC_HS_COMPLETE)
902 			goto handshake_complete;
903 	}
904 
905 out:
906 	spin_unlock_irqrestore(&lp->lock, flags);
907 
908 	send_events(lp, event_mask);
909 
910 	return IRQ_HANDLED;
911 }
912 
913 static irqreturn_t ldc_tx(int irq, void *dev_id)
914 {
915 	struct ldc_channel *lp = dev_id;
916 	unsigned long flags, orig_state;
917 	unsigned int event_mask = 0;
918 
919 	spin_lock_irqsave(&lp->lock, flags);
920 
921 	orig_state = lp->chan_state;
922 
923 	/* We should probably check for hypervisor errors here and
924 	 * reset the LDC channel if we get one.
925 	 */
926 	sun4v_ldc_tx_get_state(lp->id,
927 			       &lp->tx_head,
928 			       &lp->tx_tail,
929 			       &lp->chan_state);
930 
931 	ldcdbg(TX, " TX state[0x%02lx:0x%02lx] head[0x%04lx] tail[0x%04lx]\n",
932 	       orig_state, lp->chan_state, lp->tx_head, lp->tx_tail);
933 
934 	if (lp->cfg.mode == LDC_MODE_RAW &&
935 	    lp->chan_state == LDC_CHANNEL_UP) {
936 		lp->hs_state = LDC_HS_COMPLETE;
937 		ldc_set_state(lp, LDC_STATE_CONNECTED);
938 
939 		event_mask |= LDC_EVENT_UP;
940 	}
941 
942 	spin_unlock_irqrestore(&lp->lock, flags);
943 
944 	send_events(lp, event_mask);
945 
946 	return IRQ_HANDLED;
947 }
948 
949 /* XXX ldc_alloc() and ldc_free() needs to run under a mutex so
950  * XXX that addition and removal from the ldc_channel_list has
951  * XXX atomicity, otherwise the __ldc_channel_exists() check is
952  * XXX totally pointless as another thread can slip into ldc_alloc()
953  * XXX and add a channel with the same ID.  There also needs to be
954  * XXX a spinlock for ldc_channel_list.
955  */
956 static HLIST_HEAD(ldc_channel_list);
957 
958 static int __ldc_channel_exists(unsigned long id)
959 {
960 	struct ldc_channel *lp;
961 
962 	hlist_for_each_entry(lp, &ldc_channel_list, list) {
963 		if (lp->id == id)
964 			return 1;
965 	}
966 	return 0;
967 }
968 
969 static int alloc_queue(const char *name, unsigned long num_entries,
970 		       struct ldc_packet **base, unsigned long *ra)
971 {
972 	unsigned long size, order;
973 	void *q;
974 
975 	size = num_entries * LDC_PACKET_SIZE;
976 	order = get_order(size);
977 
978 	q = (void *) __get_free_pages(GFP_KERNEL, order);
979 	if (!q) {
980 		printk(KERN_ERR PFX "Alloc of %s queue failed with "
981 		       "size=%lu order=%lu\n", name, size, order);
982 		return -ENOMEM;
983 	}
984 
985 	memset(q, 0, PAGE_SIZE << order);
986 
987 	*base = q;
988 	*ra = __pa(q);
989 
990 	return 0;
991 }
992 
993 static void free_queue(unsigned long num_entries, struct ldc_packet *q)
994 {
995 	unsigned long size, order;
996 
997 	if (!q)
998 		return;
999 
1000 	size = num_entries * LDC_PACKET_SIZE;
1001 	order = get_order(size);
1002 
1003 	free_pages((unsigned long)q, order);
1004 }
1005 
1006 static unsigned long ldc_cookie_to_index(u64 cookie, void *arg)
1007 {
1008 	u64 szcode = cookie >> COOKIE_PGSZ_CODE_SHIFT;
1009 	/* struct ldc_iommu *ldc_iommu = (struct ldc_iommu *)arg; */
1010 
1011 	cookie &= ~COOKIE_PGSZ_CODE;
1012 
1013 	return (cookie >> (13ULL + (szcode * 3ULL)));
1014 }
1015 
1016 static void ldc_demap(struct ldc_iommu *iommu, unsigned long id, u64 cookie,
1017 		      unsigned long entry, unsigned long npages)
1018 {
1019 	struct ldc_mtable_entry *base;
1020 	unsigned long i, shift;
1021 
1022 	shift = (cookie >> COOKIE_PGSZ_CODE_SHIFT) * 3;
1023 	base = iommu->page_table + entry;
1024 	for (i = 0; i < npages; i++) {
1025 		if (base->cookie)
1026 			sun4v_ldc_revoke(id, cookie + (i << shift),
1027 					 base->cookie);
1028 		base->mte = 0;
1029 	}
1030 }
1031 
1032 /* XXX Make this configurable... XXX */
1033 #define LDC_IOTABLE_SIZE	(8 * 1024)
1034 
1035 static int ldc_iommu_init(const char *name, struct ldc_channel *lp)
1036 {
1037 	unsigned long sz, num_tsb_entries, tsbsize, order;
1038 	struct ldc_iommu *ldc_iommu = &lp->iommu;
1039 	struct iommu_map_table *iommu = &ldc_iommu->iommu_map_table;
1040 	struct ldc_mtable_entry *table;
1041 	unsigned long hv_err;
1042 	int err;
1043 
1044 	num_tsb_entries = LDC_IOTABLE_SIZE;
1045 	tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1046 	spin_lock_init(&ldc_iommu->lock);
1047 
1048 	sz = num_tsb_entries / 8;
1049 	sz = (sz + 7UL) & ~7UL;
1050 	iommu->map = kzalloc(sz, GFP_KERNEL);
1051 	if (!iommu->map) {
1052 		printk(KERN_ERR PFX "Alloc of arena map failed, sz=%lu\n", sz);
1053 		return -ENOMEM;
1054 	}
1055 	iommu_tbl_pool_init(iommu, num_tsb_entries, PAGE_SHIFT,
1056 			    NULL, false /* no large pool */,
1057 			    1 /* npools */,
1058 			    true /* skip span boundary check */);
1059 
1060 	order = get_order(tsbsize);
1061 
1062 	table = (struct ldc_mtable_entry *)
1063 		__get_free_pages(GFP_KERNEL, order);
1064 	err = -ENOMEM;
1065 	if (!table) {
1066 		printk(KERN_ERR PFX "Alloc of MTE table failed, "
1067 		       "size=%lu order=%lu\n", tsbsize, order);
1068 		goto out_free_map;
1069 	}
1070 
1071 	memset(table, 0, PAGE_SIZE << order);
1072 
1073 	ldc_iommu->page_table = table;
1074 
1075 	hv_err = sun4v_ldc_set_map_table(lp->id, __pa(table),
1076 					 num_tsb_entries);
1077 	err = -EINVAL;
1078 	if (hv_err)
1079 		goto out_free_table;
1080 
1081 	return 0;
1082 
1083 out_free_table:
1084 	free_pages((unsigned long) table, order);
1085 	ldc_iommu->page_table = NULL;
1086 
1087 out_free_map:
1088 	kfree(iommu->map);
1089 	iommu->map = NULL;
1090 
1091 	return err;
1092 }
1093 
1094 static void ldc_iommu_release(struct ldc_channel *lp)
1095 {
1096 	struct ldc_iommu *ldc_iommu = &lp->iommu;
1097 	struct iommu_map_table *iommu = &ldc_iommu->iommu_map_table;
1098 	unsigned long num_tsb_entries, tsbsize, order;
1099 
1100 	(void) sun4v_ldc_set_map_table(lp->id, 0, 0);
1101 
1102 	num_tsb_entries = iommu->poolsize * iommu->nr_pools;
1103 	tsbsize = num_tsb_entries * sizeof(struct ldc_mtable_entry);
1104 	order = get_order(tsbsize);
1105 
1106 	free_pages((unsigned long) ldc_iommu->page_table, order);
1107 	ldc_iommu->page_table = NULL;
1108 
1109 	kfree(iommu->map);
1110 	iommu->map = NULL;
1111 }
1112 
1113 struct ldc_channel *ldc_alloc(unsigned long id,
1114 			      const struct ldc_channel_config *cfgp,
1115 			      void *event_arg,
1116 			      const char *name)
1117 {
1118 	struct ldc_channel *lp;
1119 	const struct ldc_mode_ops *mops;
1120 	unsigned long dummy1, dummy2, hv_err;
1121 	u8 mss, *mssbuf;
1122 	int err;
1123 
1124 	err = -ENODEV;
1125 	if (!ldom_domaining_enabled)
1126 		goto out_err;
1127 
1128 	err = -EINVAL;
1129 	if (!cfgp)
1130 		goto out_err;
1131 	if (!name)
1132 		goto out_err;
1133 
1134 	switch (cfgp->mode) {
1135 	case LDC_MODE_RAW:
1136 		mops = &raw_ops;
1137 		mss = LDC_PACKET_SIZE;
1138 		break;
1139 
1140 	case LDC_MODE_UNRELIABLE:
1141 		mops = &nonraw_ops;
1142 		mss = LDC_PACKET_SIZE - 8;
1143 		break;
1144 
1145 	case LDC_MODE_STREAM:
1146 		mops = &stream_ops;
1147 		mss = LDC_PACKET_SIZE - 8 - 8;
1148 		break;
1149 
1150 	default:
1151 		goto out_err;
1152 	}
1153 
1154 	if (!cfgp->event || !event_arg || !cfgp->rx_irq || !cfgp->tx_irq)
1155 		goto out_err;
1156 
1157 	hv_err = sun4v_ldc_tx_qinfo(id, &dummy1, &dummy2);
1158 	err = -ENODEV;
1159 	if (hv_err == HV_ECHANNEL)
1160 		goto out_err;
1161 
1162 	err = -EEXIST;
1163 	if (__ldc_channel_exists(id))
1164 		goto out_err;
1165 
1166 	mssbuf = NULL;
1167 
1168 	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
1169 	err = -ENOMEM;
1170 	if (!lp)
1171 		goto out_err;
1172 
1173 	spin_lock_init(&lp->lock);
1174 
1175 	lp->id = id;
1176 
1177 	err = ldc_iommu_init(name, lp);
1178 	if (err)
1179 		goto out_free_ldc;
1180 
1181 	lp->mops = mops;
1182 	lp->mss = mss;
1183 
1184 	lp->cfg = *cfgp;
1185 	if (!lp->cfg.mtu)
1186 		lp->cfg.mtu = LDC_DEFAULT_MTU;
1187 
1188 	if (lp->cfg.mode == LDC_MODE_STREAM) {
1189 		mssbuf = kzalloc(lp->cfg.mtu, GFP_KERNEL);
1190 		if (!mssbuf) {
1191 			err = -ENOMEM;
1192 			goto out_free_iommu;
1193 		}
1194 		lp->mssbuf = mssbuf;
1195 	}
1196 
1197 	lp->event_arg = event_arg;
1198 
1199 	/* XXX allow setting via ldc_channel_config to override defaults
1200 	 * XXX or use some formula based upon mtu
1201 	 */
1202 	lp->tx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1203 	lp->rx_num_entries = LDC_DEFAULT_NUM_ENTRIES;
1204 
1205 	err = alloc_queue("TX", lp->tx_num_entries,
1206 			  &lp->tx_base, &lp->tx_ra);
1207 	if (err)
1208 		goto out_free_mssbuf;
1209 
1210 	err = alloc_queue("RX", lp->rx_num_entries,
1211 			  &lp->rx_base, &lp->rx_ra);
1212 	if (err)
1213 		goto out_free_txq;
1214 
1215 	lp->flags |= LDC_FLAG_ALLOCED_QUEUES;
1216 
1217 	lp->hs_state = LDC_HS_CLOSED;
1218 	ldc_set_state(lp, LDC_STATE_INIT);
1219 
1220 	INIT_HLIST_NODE(&lp->list);
1221 	hlist_add_head(&lp->list, &ldc_channel_list);
1222 
1223 	INIT_HLIST_HEAD(&lp->mh_list);
1224 
1225 	snprintf(lp->rx_irq_name, LDC_IRQ_NAME_MAX, "%s RX", name);
1226 	snprintf(lp->tx_irq_name, LDC_IRQ_NAME_MAX, "%s TX", name);
1227 
1228 	err = request_irq(lp->cfg.rx_irq, ldc_rx, 0,
1229 			  lp->rx_irq_name, lp);
1230 	if (err)
1231 		goto out_free_txq;
1232 
1233 	err = request_irq(lp->cfg.tx_irq, ldc_tx, 0,
1234 			  lp->tx_irq_name, lp);
1235 	if (err) {
1236 		free_irq(lp->cfg.rx_irq, lp);
1237 		goto out_free_txq;
1238 	}
1239 
1240 	return lp;
1241 
1242 out_free_txq:
1243 	free_queue(lp->tx_num_entries, lp->tx_base);
1244 
1245 out_free_mssbuf:
1246 	kfree(mssbuf);
1247 
1248 out_free_iommu:
1249 	ldc_iommu_release(lp);
1250 
1251 out_free_ldc:
1252 	kfree(lp);
1253 
1254 out_err:
1255 	return ERR_PTR(err);
1256 }
1257 EXPORT_SYMBOL(ldc_alloc);
1258 
1259 void ldc_unbind(struct ldc_channel *lp)
1260 {
1261 	if (lp->flags & LDC_FLAG_REGISTERED_IRQS) {
1262 		free_irq(lp->cfg.rx_irq, lp);
1263 		free_irq(lp->cfg.tx_irq, lp);
1264 		lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1265 	}
1266 
1267 	if (lp->flags & LDC_FLAG_REGISTERED_QUEUES) {
1268 		sun4v_ldc_tx_qconf(lp->id, 0, 0);
1269 		sun4v_ldc_rx_qconf(lp->id, 0, 0);
1270 		lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1271 	}
1272 	if (lp->flags & LDC_FLAG_ALLOCED_QUEUES) {
1273 		free_queue(lp->tx_num_entries, lp->tx_base);
1274 		free_queue(lp->rx_num_entries, lp->rx_base);
1275 		lp->flags &= ~LDC_FLAG_ALLOCED_QUEUES;
1276 	}
1277 
1278 	ldc_set_state(lp, LDC_STATE_INIT);
1279 }
1280 EXPORT_SYMBOL(ldc_unbind);
1281 
1282 void ldc_free(struct ldc_channel *lp)
1283 {
1284 	ldc_unbind(lp);
1285 	hlist_del(&lp->list);
1286 	kfree(lp->mssbuf);
1287 	ldc_iommu_release(lp);
1288 
1289 	kfree(lp);
1290 }
1291 EXPORT_SYMBOL(ldc_free);
1292 
1293 /* Bind the channel.  This registers the LDC queues with
1294  * the hypervisor and puts the channel into a pseudo-listening
1295  * state.  This does not initiate a handshake, ldc_connect() does
1296  * that.
1297  */
1298 int ldc_bind(struct ldc_channel *lp)
1299 {
1300 	unsigned long hv_err, flags;
1301 	int err = -EINVAL;
1302 
1303 	if (lp->state != LDC_STATE_INIT)
1304 		return -EINVAL;
1305 
1306 	spin_lock_irqsave(&lp->lock, flags);
1307 
1308 	enable_irq(lp->cfg.rx_irq);
1309 	enable_irq(lp->cfg.tx_irq);
1310 
1311 	lp->flags |= LDC_FLAG_REGISTERED_IRQS;
1312 
1313 	err = -ENODEV;
1314 	hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1315 	if (hv_err)
1316 		goto out_free_irqs;
1317 
1318 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1319 	if (hv_err)
1320 		goto out_free_irqs;
1321 
1322 	hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1323 	if (hv_err)
1324 		goto out_unmap_tx;
1325 
1326 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1327 	if (hv_err)
1328 		goto out_unmap_tx;
1329 
1330 	lp->flags |= LDC_FLAG_REGISTERED_QUEUES;
1331 
1332 	hv_err = sun4v_ldc_tx_get_state(lp->id,
1333 					&lp->tx_head,
1334 					&lp->tx_tail,
1335 					&lp->chan_state);
1336 	err = -EBUSY;
1337 	if (hv_err)
1338 		goto out_unmap_rx;
1339 
1340 	lp->tx_acked = lp->tx_head;
1341 
1342 	lp->hs_state = LDC_HS_OPEN;
1343 	ldc_set_state(lp, LDC_STATE_BOUND);
1344 
1345 	spin_unlock_irqrestore(&lp->lock, flags);
1346 
1347 	return 0;
1348 
1349 out_unmap_rx:
1350 	lp->flags &= ~LDC_FLAG_REGISTERED_QUEUES;
1351 	sun4v_ldc_rx_qconf(lp->id, 0, 0);
1352 
1353 out_unmap_tx:
1354 	sun4v_ldc_tx_qconf(lp->id, 0, 0);
1355 
1356 out_free_irqs:
1357 	lp->flags &= ~LDC_FLAG_REGISTERED_IRQS;
1358 	free_irq(lp->cfg.tx_irq, lp);
1359 	free_irq(lp->cfg.rx_irq, lp);
1360 
1361 	spin_unlock_irqrestore(&lp->lock, flags);
1362 
1363 	return err;
1364 }
1365 EXPORT_SYMBOL(ldc_bind);
1366 
1367 int ldc_connect(struct ldc_channel *lp)
1368 {
1369 	unsigned long flags;
1370 	int err;
1371 
1372 	if (lp->cfg.mode == LDC_MODE_RAW)
1373 		return -EINVAL;
1374 
1375 	spin_lock_irqsave(&lp->lock, flags);
1376 
1377 	if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1378 	    !(lp->flags & LDC_FLAG_REGISTERED_QUEUES) ||
1379 	    lp->hs_state != LDC_HS_OPEN)
1380 		err = ((lp->hs_state > LDC_HS_OPEN) ? 0 : -EINVAL);
1381 	else
1382 		err = start_handshake(lp);
1383 
1384 	spin_unlock_irqrestore(&lp->lock, flags);
1385 
1386 	return err;
1387 }
1388 EXPORT_SYMBOL(ldc_connect);
1389 
1390 int ldc_disconnect(struct ldc_channel *lp)
1391 {
1392 	unsigned long hv_err, flags;
1393 	int err;
1394 
1395 	if (lp->cfg.mode == LDC_MODE_RAW)
1396 		return -EINVAL;
1397 
1398 	if (!(lp->flags & LDC_FLAG_ALLOCED_QUEUES) ||
1399 	    !(lp->flags & LDC_FLAG_REGISTERED_QUEUES))
1400 		return -EINVAL;
1401 
1402 	spin_lock_irqsave(&lp->lock, flags);
1403 
1404 	err = -ENODEV;
1405 	hv_err = sun4v_ldc_tx_qconf(lp->id, 0, 0);
1406 	if (hv_err)
1407 		goto out_err;
1408 
1409 	hv_err = sun4v_ldc_tx_qconf(lp->id, lp->tx_ra, lp->tx_num_entries);
1410 	if (hv_err)
1411 		goto out_err;
1412 
1413 	hv_err = sun4v_ldc_rx_qconf(lp->id, 0, 0);
1414 	if (hv_err)
1415 		goto out_err;
1416 
1417 	hv_err = sun4v_ldc_rx_qconf(lp->id, lp->rx_ra, lp->rx_num_entries);
1418 	if (hv_err)
1419 		goto out_err;
1420 
1421 	ldc_set_state(lp, LDC_STATE_BOUND);
1422 	lp->hs_state = LDC_HS_OPEN;
1423 	lp->flags |= LDC_FLAG_RESET;
1424 
1425 	spin_unlock_irqrestore(&lp->lock, flags);
1426 
1427 	return 0;
1428 
1429 out_err:
1430 	sun4v_ldc_tx_qconf(lp->id, 0, 0);
1431 	sun4v_ldc_rx_qconf(lp->id, 0, 0);
1432 	free_irq(lp->cfg.tx_irq, lp);
1433 	free_irq(lp->cfg.rx_irq, lp);
1434 	lp->flags &= ~(LDC_FLAG_REGISTERED_IRQS |
1435 		       LDC_FLAG_REGISTERED_QUEUES);
1436 	ldc_set_state(lp, LDC_STATE_INIT);
1437 
1438 	spin_unlock_irqrestore(&lp->lock, flags);
1439 
1440 	return err;
1441 }
1442 EXPORT_SYMBOL(ldc_disconnect);
1443 
1444 int ldc_state(struct ldc_channel *lp)
1445 {
1446 	return lp->state;
1447 }
1448 EXPORT_SYMBOL(ldc_state);
1449 
1450 static int write_raw(struct ldc_channel *lp, const void *buf, unsigned int size)
1451 {
1452 	struct ldc_packet *p;
1453 	unsigned long new_tail;
1454 	int err;
1455 
1456 	if (size > LDC_PACKET_SIZE)
1457 		return -EMSGSIZE;
1458 
1459 	p = data_get_tx_packet(lp, &new_tail);
1460 	if (!p)
1461 		return -EAGAIN;
1462 
1463 	memcpy(p, buf, size);
1464 
1465 	err = send_tx_packet(lp, p, new_tail);
1466 	if (!err)
1467 		err = size;
1468 
1469 	return err;
1470 }
1471 
1472 static int read_raw(struct ldc_channel *lp, void *buf, unsigned int size)
1473 {
1474 	struct ldc_packet *p;
1475 	unsigned long hv_err, new;
1476 	int err;
1477 
1478 	if (size < LDC_PACKET_SIZE)
1479 		return -EINVAL;
1480 
1481 	hv_err = sun4v_ldc_rx_get_state(lp->id,
1482 					&lp->rx_head,
1483 					&lp->rx_tail,
1484 					&lp->chan_state);
1485 	if (hv_err)
1486 		return ldc_abort(lp);
1487 
1488 	if (lp->chan_state == LDC_CHANNEL_DOWN ||
1489 	    lp->chan_state == LDC_CHANNEL_RESETTING)
1490 		return -ECONNRESET;
1491 
1492 	if (lp->rx_head == lp->rx_tail)
1493 		return 0;
1494 
1495 	p = lp->rx_base + (lp->rx_head / LDC_PACKET_SIZE);
1496 	memcpy(buf, p, LDC_PACKET_SIZE);
1497 
1498 	new = rx_advance(lp, lp->rx_head);
1499 	lp->rx_head = new;
1500 
1501 	err = __set_rx_head(lp, new);
1502 	if (err < 0)
1503 		err = -ECONNRESET;
1504 	else
1505 		err = LDC_PACKET_SIZE;
1506 
1507 	return err;
1508 }
1509 
1510 static const struct ldc_mode_ops raw_ops = {
1511 	.write		=	write_raw,
1512 	.read		=	read_raw,
1513 };
1514 
1515 static int write_nonraw(struct ldc_channel *lp, const void *buf,
1516 			unsigned int size)
1517 {
1518 	unsigned long hv_err, tail;
1519 	unsigned int copied;
1520 	u32 seq;
1521 	int err;
1522 
1523 	hv_err = sun4v_ldc_tx_get_state(lp->id, &lp->tx_head, &lp->tx_tail,
1524 					&lp->chan_state);
1525 	if (unlikely(hv_err))
1526 		return -EBUSY;
1527 
1528 	if (unlikely(lp->chan_state != LDC_CHANNEL_UP))
1529 		return ldc_abort(lp);
1530 
1531 	if (!tx_has_space_for(lp, size))
1532 		return -EAGAIN;
1533 
1534 	seq = lp->snd_nxt;
1535 	copied = 0;
1536 	tail = lp->tx_tail;
1537 	while (copied < size) {
1538 		struct ldc_packet *p = lp->tx_base + (tail / LDC_PACKET_SIZE);
1539 		u8 *data = ((lp->cfg.mode == LDC_MODE_UNRELIABLE) ?
1540 			    p->u.u_data :
1541 			    p->u.r.r_data);
1542 		int data_len;
1543 
1544 		p->type = LDC_DATA;
1545 		p->stype = LDC_INFO;
1546 		p->ctrl = 0;
1547 
1548 		data_len = size - copied;
1549 		if (data_len > lp->mss)
1550 			data_len = lp->mss;
1551 
1552 		BUG_ON(data_len > LDC_LEN);
1553 
1554 		p->env = (data_len |
1555 			  (copied == 0 ? LDC_START : 0) |
1556 			  (data_len == size - copied ? LDC_STOP : 0));
1557 
1558 		p->seqid = ++seq;
1559 
1560 		ldcdbg(DATA, "SENT DATA [%02x:%02x:%02x:%02x:%08x]\n",
1561 		       p->type,
1562 		       p->stype,
1563 		       p->ctrl,
1564 		       p->env,
1565 		       p->seqid);
1566 
1567 		memcpy(data, buf, data_len);
1568 		buf += data_len;
1569 		copied += data_len;
1570 
1571 		tail = tx_advance(lp, tail);
1572 	}
1573 
1574 	err = set_tx_tail(lp, tail);
1575 	if (!err) {
1576 		lp->snd_nxt = seq;
1577 		err = size;
1578 	}
1579 
1580 	return err;
1581 }
1582 
1583 static int rx_bad_seq(struct ldc_channel *lp, struct ldc_packet *p,
1584 		      struct ldc_packet *first_frag)
1585 {
1586 	int err;
1587 
1588 	if (first_frag)
1589 		lp->rcv_nxt = first_frag->seqid - 1;
1590 
1591 	err = send_data_nack(lp, p);
1592 	if (err)
1593 		return err;
1594 
1595 	err = __set_rx_head(lp, lp->rx_tail);
1596 	if (err < 0)
1597 		return ldc_abort(lp);
1598 
1599 	return 0;
1600 }
1601 
1602 static int data_ack_nack(struct ldc_channel *lp, struct ldc_packet *p)
1603 {
1604 	if (p->stype & LDC_ACK) {
1605 		int err = process_data_ack(lp, p);
1606 		if (err)
1607 			return err;
1608 	}
1609 	if (p->stype & LDC_NACK)
1610 		return ldc_abort(lp);
1611 
1612 	return 0;
1613 }
1614 
1615 static int rx_data_wait(struct ldc_channel *lp, unsigned long cur_head)
1616 {
1617 	unsigned long dummy;
1618 	int limit = 1000;
1619 
1620 	ldcdbg(DATA, "DATA WAIT cur_head[%lx] rx_head[%lx] rx_tail[%lx]\n",
1621 	       cur_head, lp->rx_head, lp->rx_tail);
1622 	while (limit-- > 0) {
1623 		unsigned long hv_err;
1624 
1625 		hv_err = sun4v_ldc_rx_get_state(lp->id,
1626 						&dummy,
1627 						&lp->rx_tail,
1628 						&lp->chan_state);
1629 		if (hv_err)
1630 			return ldc_abort(lp);
1631 
1632 		if (lp->chan_state == LDC_CHANNEL_DOWN ||
1633 		    lp->chan_state == LDC_CHANNEL_RESETTING)
1634 			return -ECONNRESET;
1635 
1636 		if (cur_head != lp->rx_tail) {
1637 			ldcdbg(DATA, "DATA WAIT DONE "
1638 			       "head[%lx] tail[%lx] chan_state[%lx]\n",
1639 			       dummy, lp->rx_tail, lp->chan_state);
1640 			return 0;
1641 		}
1642 
1643 		udelay(1);
1644 	}
1645 	return -EAGAIN;
1646 }
1647 
1648 static int rx_set_head(struct ldc_channel *lp, unsigned long head)
1649 {
1650 	int err = __set_rx_head(lp, head);
1651 
1652 	if (err < 0)
1653 		return ldc_abort(lp);
1654 
1655 	lp->rx_head = head;
1656 	return 0;
1657 }
1658 
1659 static void send_data_ack(struct ldc_channel *lp)
1660 {
1661 	unsigned long new_tail;
1662 	struct ldc_packet *p;
1663 
1664 	p = data_get_tx_packet(lp, &new_tail);
1665 	if (likely(p)) {
1666 		int err;
1667 
1668 		memset(p, 0, sizeof(*p));
1669 		p->type = LDC_DATA;
1670 		p->stype = LDC_ACK;
1671 		p->ctrl = 0;
1672 		p->seqid = lp->snd_nxt + 1;
1673 		p->u.r.ackid = lp->rcv_nxt;
1674 
1675 		err = send_tx_packet(lp, p, new_tail);
1676 		if (!err)
1677 			lp->snd_nxt++;
1678 	}
1679 }
1680 
1681 static int read_nonraw(struct ldc_channel *lp, void *buf, unsigned int size)
1682 {
1683 	struct ldc_packet *first_frag;
1684 	unsigned long hv_err, new;
1685 	int err, copied;
1686 
1687 	hv_err = sun4v_ldc_rx_get_state(lp->id,
1688 					&lp->rx_head,
1689 					&lp->rx_tail,
1690 					&lp->chan_state);
1691 	if (hv_err)
1692 		return ldc_abort(lp);
1693 
1694 	if (lp->chan_state == LDC_CHANNEL_DOWN ||
1695 	    lp->chan_state == LDC_CHANNEL_RESETTING)
1696 		return -ECONNRESET;
1697 
1698 	if (lp->rx_head == lp->rx_tail)
1699 		return 0;
1700 
1701 	first_frag = NULL;
1702 	copied = err = 0;
1703 	new = lp->rx_head;
1704 	while (1) {
1705 		struct ldc_packet *p;
1706 		int pkt_len;
1707 
1708 		BUG_ON(new == lp->rx_tail);
1709 		p = lp->rx_base + (new / LDC_PACKET_SIZE);
1710 
1711 		ldcdbg(RX, "RX read pkt[%02x:%02x:%02x:%02x:%08x:%08x] "
1712 		       "rcv_nxt[%08x]\n",
1713 		       p->type,
1714 		       p->stype,
1715 		       p->ctrl,
1716 		       p->env,
1717 		       p->seqid,
1718 		       p->u.r.ackid,
1719 		       lp->rcv_nxt);
1720 
1721 		if (unlikely(!rx_seq_ok(lp, p->seqid))) {
1722 			err = rx_bad_seq(lp, p, first_frag);
1723 			copied = 0;
1724 			break;
1725 		}
1726 
1727 		if (p->type & LDC_CTRL) {
1728 			err = process_control_frame(lp, p);
1729 			if (err < 0)
1730 				break;
1731 			err = 0;
1732 		}
1733 
1734 		lp->rcv_nxt = p->seqid;
1735 
1736 		if (!(p->type & LDC_DATA)) {
1737 			new = rx_advance(lp, new);
1738 			goto no_data;
1739 		}
1740 		if (p->stype & (LDC_ACK | LDC_NACK)) {
1741 			err = data_ack_nack(lp, p);
1742 			if (err)
1743 				break;
1744 		}
1745 		if (!(p->stype & LDC_INFO)) {
1746 			new = rx_advance(lp, new);
1747 			err = rx_set_head(lp, new);
1748 			if (err)
1749 				break;
1750 			goto no_data;
1751 		}
1752 
1753 		pkt_len = p->env & LDC_LEN;
1754 
1755 		/* Every initial packet starts with the START bit set.
1756 		 *
1757 		 * Singleton packets will have both START+STOP set.
1758 		 *
1759 		 * Fragments will have START set in the first frame, STOP
1760 		 * set in the last frame, and neither bit set in middle
1761 		 * frames of the packet.
1762 		 *
1763 		 * Therefore if we are at the beginning of a packet and
1764 		 * we don't see START, or we are in the middle of a fragmented
1765 		 * packet and do see START, we are unsynchronized and should
1766 		 * flush the RX queue.
1767 		 */
1768 		if ((first_frag == NULL && !(p->env & LDC_START)) ||
1769 		    (first_frag != NULL &&  (p->env & LDC_START))) {
1770 			if (!first_frag)
1771 				new = rx_advance(lp, new);
1772 
1773 			err = rx_set_head(lp, new);
1774 			if (err)
1775 				break;
1776 
1777 			if (!first_frag)
1778 				goto no_data;
1779 		}
1780 		if (!first_frag)
1781 			first_frag = p;
1782 
1783 		if (pkt_len > size - copied) {
1784 			/* User didn't give us a big enough buffer,
1785 			 * what to do?  This is a pretty serious error.
1786 			 *
1787 			 * Since we haven't updated the RX ring head to
1788 			 * consume any of the packets, signal the error
1789 			 * to the user and just leave the RX ring alone.
1790 			 *
1791 			 * This seems the best behavior because this allows
1792 			 * a user of the LDC layer to start with a small
1793 			 * RX buffer for ldc_read() calls and use -EMSGSIZE
1794 			 * as a cue to enlarge it's read buffer.
1795 			 */
1796 			err = -EMSGSIZE;
1797 			break;
1798 		}
1799 
1800 		/* Ok, we are gonna eat this one.  */
1801 		new = rx_advance(lp, new);
1802 
1803 		memcpy(buf,
1804 		       (lp->cfg.mode == LDC_MODE_UNRELIABLE ?
1805 			p->u.u_data : p->u.r.r_data), pkt_len);
1806 		buf += pkt_len;
1807 		copied += pkt_len;
1808 
1809 		if (p->env & LDC_STOP)
1810 			break;
1811 
1812 no_data:
1813 		if (new == lp->rx_tail) {
1814 			err = rx_data_wait(lp, new);
1815 			if (err)
1816 				break;
1817 		}
1818 	}
1819 
1820 	if (!err)
1821 		err = rx_set_head(lp, new);
1822 
1823 	if (err && first_frag)
1824 		lp->rcv_nxt = first_frag->seqid - 1;
1825 
1826 	if (!err) {
1827 		err = copied;
1828 		if (err > 0 && lp->cfg.mode != LDC_MODE_UNRELIABLE)
1829 			send_data_ack(lp);
1830 	}
1831 
1832 	return err;
1833 }
1834 
1835 static const struct ldc_mode_ops nonraw_ops = {
1836 	.write		=	write_nonraw,
1837 	.read		=	read_nonraw,
1838 };
1839 
1840 static int write_stream(struct ldc_channel *lp, const void *buf,
1841 			unsigned int size)
1842 {
1843 	if (size > lp->cfg.mtu)
1844 		size = lp->cfg.mtu;
1845 	return write_nonraw(lp, buf, size);
1846 }
1847 
1848 static int read_stream(struct ldc_channel *lp, void *buf, unsigned int size)
1849 {
1850 	if (!lp->mssbuf_len) {
1851 		int err = read_nonraw(lp, lp->mssbuf, lp->cfg.mtu);
1852 		if (err < 0)
1853 			return err;
1854 
1855 		lp->mssbuf_len = err;
1856 		lp->mssbuf_off = 0;
1857 	}
1858 
1859 	if (size > lp->mssbuf_len)
1860 		size = lp->mssbuf_len;
1861 	memcpy(buf, lp->mssbuf + lp->mssbuf_off, size);
1862 
1863 	lp->mssbuf_off += size;
1864 	lp->mssbuf_len -= size;
1865 
1866 	return size;
1867 }
1868 
1869 static const struct ldc_mode_ops stream_ops = {
1870 	.write		=	write_stream,
1871 	.read		=	read_stream,
1872 };
1873 
1874 int ldc_write(struct ldc_channel *lp, const void *buf, unsigned int size)
1875 {
1876 	unsigned long flags;
1877 	int err;
1878 
1879 	if (!buf)
1880 		return -EINVAL;
1881 
1882 	if (!size)
1883 		return 0;
1884 
1885 	spin_lock_irqsave(&lp->lock, flags);
1886 
1887 	if (lp->hs_state != LDC_HS_COMPLETE)
1888 		err = -ENOTCONN;
1889 	else
1890 		err = lp->mops->write(lp, buf, size);
1891 
1892 	spin_unlock_irqrestore(&lp->lock, flags);
1893 
1894 	return err;
1895 }
1896 EXPORT_SYMBOL(ldc_write);
1897 
1898 int ldc_read(struct ldc_channel *lp, void *buf, unsigned int size)
1899 {
1900 	unsigned long flags;
1901 	int err;
1902 
1903 	if (!buf)
1904 		return -EINVAL;
1905 
1906 	if (!size)
1907 		return 0;
1908 
1909 	spin_lock_irqsave(&lp->lock, flags);
1910 
1911 	if (lp->hs_state != LDC_HS_COMPLETE)
1912 		err = -ENOTCONN;
1913 	else
1914 		err = lp->mops->read(lp, buf, size);
1915 
1916 	spin_unlock_irqrestore(&lp->lock, flags);
1917 
1918 	return err;
1919 }
1920 EXPORT_SYMBOL(ldc_read);
1921 
1922 static u64 pagesize_code(void)
1923 {
1924 	switch (PAGE_SIZE) {
1925 	default:
1926 	case (8ULL * 1024ULL):
1927 		return 0;
1928 	case (64ULL * 1024ULL):
1929 		return 1;
1930 	case (512ULL * 1024ULL):
1931 		return 2;
1932 	case (4ULL * 1024ULL * 1024ULL):
1933 		return 3;
1934 	case (32ULL * 1024ULL * 1024ULL):
1935 		return 4;
1936 	case (256ULL * 1024ULL * 1024ULL):
1937 		return 5;
1938 	}
1939 }
1940 
1941 static u64 make_cookie(u64 index, u64 pgsz_code, u64 page_offset)
1942 {
1943 	return ((pgsz_code << COOKIE_PGSZ_CODE_SHIFT) |
1944 		(index << PAGE_SHIFT) |
1945 		page_offset);
1946 }
1947 
1948 
1949 static struct ldc_mtable_entry *alloc_npages(struct ldc_iommu *iommu,
1950 					     unsigned long npages)
1951 {
1952 	long entry;
1953 
1954 	entry = iommu_tbl_range_alloc(NULL, &iommu->iommu_map_table,
1955 				      npages, NULL, (unsigned long)-1, 0);
1956 	if (unlikely(entry == IOMMU_ERROR_CODE))
1957 		return NULL;
1958 
1959 	return iommu->page_table + entry;
1960 }
1961 
1962 static u64 perm_to_mte(unsigned int map_perm)
1963 {
1964 	u64 mte_base;
1965 
1966 	mte_base = pagesize_code();
1967 
1968 	if (map_perm & LDC_MAP_SHADOW) {
1969 		if (map_perm & LDC_MAP_R)
1970 			mte_base |= LDC_MTE_COPY_R;
1971 		if (map_perm & LDC_MAP_W)
1972 			mte_base |= LDC_MTE_COPY_W;
1973 	}
1974 	if (map_perm & LDC_MAP_DIRECT) {
1975 		if (map_perm & LDC_MAP_R)
1976 			mte_base |= LDC_MTE_READ;
1977 		if (map_perm & LDC_MAP_W)
1978 			mte_base |= LDC_MTE_WRITE;
1979 		if (map_perm & LDC_MAP_X)
1980 			mte_base |= LDC_MTE_EXEC;
1981 	}
1982 	if (map_perm & LDC_MAP_IO) {
1983 		if (map_perm & LDC_MAP_R)
1984 			mte_base |= LDC_MTE_IOMMU_R;
1985 		if (map_perm & LDC_MAP_W)
1986 			mte_base |= LDC_MTE_IOMMU_W;
1987 	}
1988 
1989 	return mte_base;
1990 }
1991 
1992 static int pages_in_region(unsigned long base, long len)
1993 {
1994 	int count = 0;
1995 
1996 	do {
1997 		unsigned long new = (base + PAGE_SIZE) & PAGE_MASK;
1998 
1999 		len -= (new - base);
2000 		base = new;
2001 		count++;
2002 	} while (len > 0);
2003 
2004 	return count;
2005 }
2006 
2007 struct cookie_state {
2008 	struct ldc_mtable_entry		*page_table;
2009 	struct ldc_trans_cookie		*cookies;
2010 	u64				mte_base;
2011 	u64				prev_cookie;
2012 	u32				pte_idx;
2013 	u32				nc;
2014 };
2015 
2016 static void fill_cookies(struct cookie_state *sp, unsigned long pa,
2017 			 unsigned long off, unsigned long len)
2018 {
2019 	do {
2020 		unsigned long tlen, new = pa + PAGE_SIZE;
2021 		u64 this_cookie;
2022 
2023 		sp->page_table[sp->pte_idx].mte = sp->mte_base | pa;
2024 
2025 		tlen = PAGE_SIZE;
2026 		if (off)
2027 			tlen = PAGE_SIZE - off;
2028 		if (tlen > len)
2029 			tlen = len;
2030 
2031 		this_cookie = make_cookie(sp->pte_idx,
2032 					  pagesize_code(), off);
2033 
2034 		off = 0;
2035 
2036 		if (this_cookie == sp->prev_cookie) {
2037 			sp->cookies[sp->nc - 1].cookie_size += tlen;
2038 		} else {
2039 			sp->cookies[sp->nc].cookie_addr = this_cookie;
2040 			sp->cookies[sp->nc].cookie_size = tlen;
2041 			sp->nc++;
2042 		}
2043 		sp->prev_cookie = this_cookie + tlen;
2044 
2045 		sp->pte_idx++;
2046 
2047 		len -= tlen;
2048 		pa = new;
2049 	} while (len > 0);
2050 }
2051 
2052 static int sg_count_one(struct scatterlist *sg)
2053 {
2054 	unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
2055 	long len = sg->length;
2056 
2057 	if ((sg->offset | len) & (8UL - 1))
2058 		return -EFAULT;
2059 
2060 	return pages_in_region(base + sg->offset, len);
2061 }
2062 
2063 static int sg_count_pages(struct scatterlist *sg, int num_sg)
2064 {
2065 	int count;
2066 	int i;
2067 
2068 	count = 0;
2069 	for (i = 0; i < num_sg; i++) {
2070 		int err = sg_count_one(sg + i);
2071 		if (err < 0)
2072 			return err;
2073 		count += err;
2074 	}
2075 
2076 	return count;
2077 }
2078 
2079 int ldc_map_sg(struct ldc_channel *lp,
2080 	       struct scatterlist *sg, int num_sg,
2081 	       struct ldc_trans_cookie *cookies, int ncookies,
2082 	       unsigned int map_perm)
2083 {
2084 	unsigned long i, npages;
2085 	struct ldc_mtable_entry *base;
2086 	struct cookie_state state;
2087 	struct ldc_iommu *iommu;
2088 	int err;
2089 	struct scatterlist *s;
2090 
2091 	if (map_perm & ~LDC_MAP_ALL)
2092 		return -EINVAL;
2093 
2094 	err = sg_count_pages(sg, num_sg);
2095 	if (err < 0)
2096 		return err;
2097 
2098 	npages = err;
2099 	if (err > ncookies)
2100 		return -EMSGSIZE;
2101 
2102 	iommu = &lp->iommu;
2103 
2104 	base = alloc_npages(iommu, npages);
2105 
2106 	if (!base)
2107 		return -ENOMEM;
2108 
2109 	state.page_table = iommu->page_table;
2110 	state.cookies = cookies;
2111 	state.mte_base = perm_to_mte(map_perm);
2112 	state.prev_cookie = ~(u64)0;
2113 	state.pte_idx = (base - iommu->page_table);
2114 	state.nc = 0;
2115 
2116 	for_each_sg(sg, s, num_sg, i) {
2117 		fill_cookies(&state, page_to_pfn(sg_page(s)) << PAGE_SHIFT,
2118 			     s->offset, s->length);
2119 	}
2120 
2121 	return state.nc;
2122 }
2123 EXPORT_SYMBOL(ldc_map_sg);
2124 
2125 int ldc_map_single(struct ldc_channel *lp,
2126 		   void *buf, unsigned int len,
2127 		   struct ldc_trans_cookie *cookies, int ncookies,
2128 		   unsigned int map_perm)
2129 {
2130 	unsigned long npages, pa;
2131 	struct ldc_mtable_entry *base;
2132 	struct cookie_state state;
2133 	struct ldc_iommu *iommu;
2134 
2135 	if ((map_perm & ~LDC_MAP_ALL) || (ncookies < 1))
2136 		return -EINVAL;
2137 
2138 	pa = __pa(buf);
2139 	if ((pa | len) & (8UL - 1))
2140 		return -EFAULT;
2141 
2142 	npages = pages_in_region(pa, len);
2143 
2144 	iommu = &lp->iommu;
2145 
2146 	base = alloc_npages(iommu, npages);
2147 
2148 	if (!base)
2149 		return -ENOMEM;
2150 
2151 	state.page_table = iommu->page_table;
2152 	state.cookies = cookies;
2153 	state.mte_base = perm_to_mte(map_perm);
2154 	state.prev_cookie = ~(u64)0;
2155 	state.pte_idx = (base - iommu->page_table);
2156 	state.nc = 0;
2157 	fill_cookies(&state, (pa & PAGE_MASK), (pa & ~PAGE_MASK), len);
2158 	BUG_ON(state.nc > ncookies);
2159 
2160 	return state.nc;
2161 }
2162 EXPORT_SYMBOL(ldc_map_single);
2163 
2164 
2165 static void free_npages(unsigned long id, struct ldc_iommu *iommu,
2166 			u64 cookie, u64 size)
2167 {
2168 	unsigned long npages, entry;
2169 
2170 	npages = PAGE_ALIGN(((cookie & ~PAGE_MASK) + size)) >> PAGE_SHIFT;
2171 
2172 	entry = ldc_cookie_to_index(cookie, iommu);
2173 	ldc_demap(iommu, id, cookie, entry, npages);
2174 	iommu_tbl_range_free(&iommu->iommu_map_table, cookie, npages, entry);
2175 }
2176 
2177 void ldc_unmap(struct ldc_channel *lp, struct ldc_trans_cookie *cookies,
2178 	       int ncookies)
2179 {
2180 	struct ldc_iommu *iommu = &lp->iommu;
2181 	int i;
2182 	unsigned long flags;
2183 
2184 	spin_lock_irqsave(&iommu->lock, flags);
2185 	for (i = 0; i < ncookies; i++) {
2186 		u64 addr = cookies[i].cookie_addr;
2187 		u64 size = cookies[i].cookie_size;
2188 
2189 		free_npages(lp->id, iommu, addr, size);
2190 	}
2191 	spin_unlock_irqrestore(&iommu->lock, flags);
2192 }
2193 EXPORT_SYMBOL(ldc_unmap);
2194 
2195 int ldc_copy(struct ldc_channel *lp, int copy_dir,
2196 	     void *buf, unsigned int len, unsigned long offset,
2197 	     struct ldc_trans_cookie *cookies, int ncookies)
2198 {
2199 	unsigned int orig_len;
2200 	unsigned long ra;
2201 	int i;
2202 
2203 	if (copy_dir != LDC_COPY_IN && copy_dir != LDC_COPY_OUT) {
2204 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Bad copy_dir[%d]\n",
2205 		       lp->id, copy_dir);
2206 		return -EINVAL;
2207 	}
2208 
2209 	ra = __pa(buf);
2210 	if ((ra | len | offset) & (8UL - 1)) {
2211 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Unaligned buffer "
2212 		       "ra[%lx] len[%x] offset[%lx]\n",
2213 		       lp->id, ra, len, offset);
2214 		return -EFAULT;
2215 	}
2216 
2217 	if (lp->hs_state != LDC_HS_COMPLETE ||
2218 	    (lp->flags & LDC_FLAG_RESET)) {
2219 		printk(KERN_ERR PFX "ldc_copy: ID[%lu] Link down hs_state[%x] "
2220 		       "flags[%x]\n", lp->id, lp->hs_state, lp->flags);
2221 		return -ECONNRESET;
2222 	}
2223 
2224 	orig_len = len;
2225 	for (i = 0; i < ncookies; i++) {
2226 		unsigned long cookie_raddr = cookies[i].cookie_addr;
2227 		unsigned long this_len = cookies[i].cookie_size;
2228 		unsigned long actual_len;
2229 
2230 		if (unlikely(offset)) {
2231 			unsigned long this_off = offset;
2232 
2233 			if (this_off > this_len)
2234 				this_off = this_len;
2235 
2236 			offset -= this_off;
2237 			this_len -= this_off;
2238 			if (!this_len)
2239 				continue;
2240 			cookie_raddr += this_off;
2241 		}
2242 
2243 		if (this_len > len)
2244 			this_len = len;
2245 
2246 		while (1) {
2247 			unsigned long hv_err;
2248 
2249 			hv_err = sun4v_ldc_copy(lp->id, copy_dir,
2250 						cookie_raddr, ra,
2251 						this_len, &actual_len);
2252 			if (unlikely(hv_err)) {
2253 				printk(KERN_ERR PFX "ldc_copy: ID[%lu] "
2254 				       "HV error %lu\n",
2255 				       lp->id, hv_err);
2256 				if (lp->hs_state != LDC_HS_COMPLETE ||
2257 				    (lp->flags & LDC_FLAG_RESET))
2258 					return -ECONNRESET;
2259 				else
2260 					return -EFAULT;
2261 			}
2262 
2263 			cookie_raddr += actual_len;
2264 			ra += actual_len;
2265 			len -= actual_len;
2266 			if (actual_len == this_len)
2267 				break;
2268 
2269 			this_len -= actual_len;
2270 		}
2271 
2272 		if (!len)
2273 			break;
2274 	}
2275 
2276 	/* It is caller policy what to do about short copies.
2277 	 * For example, a networking driver can declare the
2278 	 * packet a runt and drop it.
2279 	 */
2280 
2281 	return orig_len - len;
2282 }
2283 EXPORT_SYMBOL(ldc_copy);
2284 
2285 void *ldc_alloc_exp_dring(struct ldc_channel *lp, unsigned int len,
2286 			  struct ldc_trans_cookie *cookies, int *ncookies,
2287 			  unsigned int map_perm)
2288 {
2289 	void *buf;
2290 	int err;
2291 
2292 	if (len & (8UL - 1))
2293 		return ERR_PTR(-EINVAL);
2294 
2295 	buf = kzalloc(len, GFP_ATOMIC);
2296 	if (!buf)
2297 		return ERR_PTR(-ENOMEM);
2298 
2299 	err = ldc_map_single(lp, buf, len, cookies, *ncookies, map_perm);
2300 	if (err < 0) {
2301 		kfree(buf);
2302 		return ERR_PTR(err);
2303 	}
2304 	*ncookies = err;
2305 
2306 	return buf;
2307 }
2308 EXPORT_SYMBOL(ldc_alloc_exp_dring);
2309 
2310 void ldc_free_exp_dring(struct ldc_channel *lp, void *buf, unsigned int len,
2311 			struct ldc_trans_cookie *cookies, int ncookies)
2312 {
2313 	ldc_unmap(lp, cookies, ncookies);
2314 	kfree(buf);
2315 }
2316 EXPORT_SYMBOL(ldc_free_exp_dring);
2317 
2318 static int __init ldc_init(void)
2319 {
2320 	unsigned long major, minor;
2321 	struct mdesc_handle *hp;
2322 	const u64 *v;
2323 	int err;
2324 	u64 mp;
2325 
2326 	hp = mdesc_grab();
2327 	if (!hp)
2328 		return -ENODEV;
2329 
2330 	mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform");
2331 	err = -ENODEV;
2332 	if (mp == MDESC_NODE_NULL)
2333 		goto out;
2334 
2335 	v = mdesc_get_property(hp, mp, "domaining-enabled", NULL);
2336 	if (!v)
2337 		goto out;
2338 
2339 	major = 1;
2340 	minor = 0;
2341 	if (sun4v_hvapi_register(HV_GRP_LDOM, major, &minor)) {
2342 		printk(KERN_INFO PFX "Could not register LDOM hvapi.\n");
2343 		goto out;
2344 	}
2345 
2346 	printk(KERN_INFO "%s", version);
2347 
2348 	if (!*v) {
2349 		printk(KERN_INFO PFX "Domaining disabled.\n");
2350 		goto out;
2351 	}
2352 	ldom_domaining_enabled = 1;
2353 	err = 0;
2354 
2355 out:
2356 	mdesc_release(hp);
2357 	return err;
2358 }
2359 
2360 core_initcall(ldc_init);
2361