vmbus_chan.c revision 307595
1/*-
2 * Copyright (c) 2009-2012,2016 Microsoft Corp.
3 * Copyright (c) 2012 NetApp Inc.
4 * Copyright (c) 2012 Citrix Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/11/sys/dev/hyperv/vmbus/vmbus_chan.c 307595 2016-10-19 02:14:04Z sephe $");
31
32#include <sys/param.h>
33#include <sys/kernel.h>
34#include <sys/lock.h>
35#include <sys/malloc.h>
36#include <sys/mutex.h>
37#include <sys/smp.h>
38#include <sys/sysctl.h>
39#include <sys/systm.h>
40
41#include <machine/atomic.h>
42
43#include <dev/hyperv/include/hyperv_busdma.h>
44#include <dev/hyperv/vmbus/hyperv_var.h>
45#include <dev/hyperv/vmbus/vmbus_reg.h>
46#include <dev/hyperv/vmbus/vmbus_var.h>
47#include <dev/hyperv/vmbus/vmbus_brvar.h>
48#include <dev/hyperv/vmbus/vmbus_chanvar.h>
49
50static void			vmbus_chan_update_evtflagcnt(
51				    struct vmbus_softc *,
52				    const struct vmbus_channel *);
53static void			vmbus_chan_close_internal(
54				    struct vmbus_channel *);
55static int			vmbus_chan_sysctl_mnf(SYSCTL_HANDLER_ARGS);
56static void			vmbus_chan_sysctl_create(
57				    struct vmbus_channel *);
58static struct vmbus_channel	*vmbus_chan_alloc(struct vmbus_softc *);
59static void			vmbus_chan_free(struct vmbus_channel *);
60static int			vmbus_chan_add(struct vmbus_channel *);
61static void			vmbus_chan_cpu_default(struct vmbus_channel *);
62
63static void			vmbus_chan_task(void *, int);
64static void			vmbus_chan_task_nobatch(void *, int);
65static void			vmbus_chan_detach_task(void *, int);
66
67static void			vmbus_chan_msgproc_choffer(struct vmbus_softc *,
68				    const struct vmbus_message *);
69static void			vmbus_chan_msgproc_chrescind(
70				    struct vmbus_softc *,
71				    const struct vmbus_message *);
72
73/*
74 * Vmbus channel message processing.
75 */
76static const vmbus_chanmsg_proc_t
77vmbus_chan_msgprocs[VMBUS_CHANMSG_TYPE_MAX] = {
78	VMBUS_CHANMSG_PROC(CHOFFER,	vmbus_chan_msgproc_choffer),
79	VMBUS_CHANMSG_PROC(CHRESCIND,	vmbus_chan_msgproc_chrescind),
80
81	VMBUS_CHANMSG_PROC_WAKEUP(CHOPEN_RESP),
82	VMBUS_CHANMSG_PROC_WAKEUP(GPADL_CONNRESP),
83	VMBUS_CHANMSG_PROC_WAKEUP(GPADL_DISCONNRESP)
84};
85
86/*
87 * Notify host that there are data pending on our TX bufring.
88 */
89static __inline void
90vmbus_chan_signal_tx(const struct vmbus_channel *chan)
91{
92	atomic_set_long(chan->ch_evtflag, chan->ch_evtflag_mask);
93	if (chan->ch_txflags & VMBUS_CHAN_TXF_HASMNF)
94		atomic_set_int(chan->ch_montrig, chan->ch_montrig_mask);
95	else
96		hypercall_signal_event(chan->ch_monprm_dma.hv_paddr);
97}
98
99static int
100vmbus_chan_sysctl_mnf(SYSCTL_HANDLER_ARGS)
101{
102	struct vmbus_channel *chan = arg1;
103	int mnf = 0;
104
105	if (chan->ch_txflags & VMBUS_CHAN_TXF_HASMNF)
106		mnf = 1;
107	return sysctl_handle_int(oidp, &mnf, 0, req);
108}
109
110static void
111vmbus_chan_sysctl_create(struct vmbus_channel *chan)
112{
113	struct sysctl_oid *ch_tree, *chid_tree, *br_tree;
114	struct sysctl_ctx_list *ctx;
115	uint32_t ch_id;
116	char name[16];
117
118	/*
119	 * Add sysctl nodes related to this channel to this
120	 * channel's sysctl ctx, so that they can be destroyed
121	 * independently upon close of this channel, which can
122	 * happen even if the device is not detached.
123	 */
124	ctx = &chan->ch_sysctl_ctx;
125	sysctl_ctx_init(ctx);
126
127	/*
128	 * Create dev.NAME.UNIT.channel tree.
129	 */
130	ch_tree = SYSCTL_ADD_NODE(ctx,
131	    SYSCTL_CHILDREN(device_get_sysctl_tree(chan->ch_dev)),
132	    OID_AUTO, "channel", CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
133	if (ch_tree == NULL)
134		return;
135
136	/*
137	 * Create dev.NAME.UNIT.channel.CHANID tree.
138	 */
139	if (VMBUS_CHAN_ISPRIMARY(chan))
140		ch_id = chan->ch_id;
141	else
142		ch_id = chan->ch_prichan->ch_id;
143	snprintf(name, sizeof(name), "%d", ch_id);
144	chid_tree = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(ch_tree),
145	    OID_AUTO, name, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
146	if (chid_tree == NULL)
147		return;
148
149	if (!VMBUS_CHAN_ISPRIMARY(chan)) {
150		/*
151		 * Create dev.NAME.UNIT.channel.CHANID.sub tree.
152		 */
153		ch_tree = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(chid_tree),
154		    OID_AUTO, "sub", CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
155		if (ch_tree == NULL)
156			return;
157
158		/*
159		 * Create dev.NAME.UNIT.channel.CHANID.sub.SUBIDX tree.
160		 *
161		 * NOTE:
162		 * chid_tree is changed to this new sysctl tree.
163		 */
164		snprintf(name, sizeof(name), "%d", chan->ch_subidx);
165		chid_tree = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(ch_tree),
166		    OID_AUTO, name, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
167		if (chid_tree == NULL)
168			return;
169
170		SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(chid_tree), OID_AUTO,
171		    "chanid", CTLFLAG_RD, &chan->ch_id, 0, "channel id");
172	}
173
174	SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(chid_tree), OID_AUTO,
175	    "cpu", CTLFLAG_RD, &chan->ch_cpuid, 0, "owner CPU id");
176	SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(chid_tree), OID_AUTO,
177	    "mnf", CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
178	    chan, 0, vmbus_chan_sysctl_mnf, "I",
179	    "has monitor notification facilities");
180
181	br_tree = SYSCTL_ADD_NODE(ctx, SYSCTL_CHILDREN(chid_tree), OID_AUTO,
182	    "br", CTLFLAG_RD | CTLFLAG_MPSAFE, 0, "");
183	if (br_tree != NULL) {
184		/*
185		 * Create sysctl tree for RX bufring.
186		 */
187		vmbus_br_sysctl_create(ctx, br_tree, &chan->ch_rxbr.rxbr, "rx");
188		/*
189		 * Create sysctl tree for TX bufring.
190		 */
191		vmbus_br_sysctl_create(ctx, br_tree, &chan->ch_txbr.txbr, "tx");
192	}
193}
194
195int
196vmbus_chan_open(struct vmbus_channel *chan, int txbr_size, int rxbr_size,
197    const void *udata, int udlen, vmbus_chan_callback_t cb, void *cbarg)
198{
199	struct vmbus_chan_br cbr;
200	int error;
201
202	/*
203	 * Allocate the TX+RX bufrings.
204	 */
205	KASSERT(chan->ch_bufring == NULL, ("bufrings are allocated"));
206	chan->ch_bufring = hyperv_dmamem_alloc(bus_get_dma_tag(chan->ch_dev),
207	    PAGE_SIZE, 0, txbr_size + rxbr_size, &chan->ch_bufring_dma,
208	    BUS_DMA_WAITOK);
209	if (chan->ch_bufring == NULL) {
210		device_printf(chan->ch_dev, "bufring allocation failed\n");
211		return (ENOMEM);
212	}
213
214	cbr.cbr = chan->ch_bufring;
215	cbr.cbr_paddr = chan->ch_bufring_dma.hv_paddr;
216	cbr.cbr_txsz = txbr_size;
217	cbr.cbr_rxsz = rxbr_size;
218
219	error = vmbus_chan_open_br(chan, &cbr, udata, udlen, cb, cbarg);
220	if (error) {
221		hyperv_dmamem_free(&chan->ch_bufring_dma, chan->ch_bufring);
222		chan->ch_bufring = NULL;
223	}
224	return (error);
225}
226
227int
228vmbus_chan_open_br(struct vmbus_channel *chan, const struct vmbus_chan_br *cbr,
229    const void *udata, int udlen, vmbus_chan_callback_t cb, void *cbarg)
230{
231	struct vmbus_softc *sc = chan->ch_vmbus;
232	const struct vmbus_chanmsg_chopen_resp *resp;
233	const struct vmbus_message *msg;
234	struct vmbus_chanmsg_chopen *req;
235	struct vmbus_msghc *mh;
236	uint32_t status;
237	int error, txbr_size, rxbr_size;
238	uint8_t *br;
239
240	if (udlen > VMBUS_CHANMSG_CHOPEN_UDATA_SIZE) {
241		device_printf(sc->vmbus_dev,
242		    "invalid udata len %d for chan%u\n", udlen, chan->ch_id);
243		return EINVAL;
244	}
245
246	br = cbr->cbr;
247	txbr_size = cbr->cbr_txsz;
248	rxbr_size = cbr->cbr_rxsz;
249	KASSERT((txbr_size & PAGE_MASK) == 0,
250	    ("send bufring size is not multiple page"));
251	KASSERT((rxbr_size & PAGE_MASK) == 0,
252	    ("recv bufring size is not multiple page"));
253	KASSERT((cbr->cbr_paddr & PAGE_MASK) == 0,
254	    ("bufring is not page aligned"));
255
256	/*
257	 * Zero out the TX/RX bufrings, in case that they were used before.
258	 */
259	memset(br, 0, txbr_size + rxbr_size);
260
261	if (atomic_testandset_int(&chan->ch_stflags,
262	    VMBUS_CHAN_ST_OPENED_SHIFT))
263		panic("double-open chan%u", chan->ch_id);
264
265	chan->ch_cb = cb;
266	chan->ch_cbarg = cbarg;
267
268	vmbus_chan_update_evtflagcnt(sc, chan);
269
270	chan->ch_tq = VMBUS_PCPU_GET(chan->ch_vmbus, event_tq, chan->ch_cpuid);
271	if (chan->ch_flags & VMBUS_CHAN_FLAG_BATCHREAD)
272		TASK_INIT(&chan->ch_task, 0, vmbus_chan_task, chan);
273	else
274		TASK_INIT(&chan->ch_task, 0, vmbus_chan_task_nobatch, chan);
275
276	/* TX bufring comes first */
277	vmbus_txbr_setup(&chan->ch_txbr, br, txbr_size);
278	/* RX bufring immediately follows TX bufring */
279	vmbus_rxbr_setup(&chan->ch_rxbr, br + txbr_size, rxbr_size);
280
281	/* Create sysctl tree for this channel */
282	vmbus_chan_sysctl_create(chan);
283
284	/*
285	 * Connect the bufrings, both RX and TX, to this channel.
286	 */
287	error = vmbus_chan_gpadl_connect(chan, cbr->cbr_paddr,
288	    txbr_size + rxbr_size, &chan->ch_bufring_gpadl);
289	if (error) {
290		device_printf(sc->vmbus_dev,
291		    "failed to connect bufring GPADL to chan%u\n", chan->ch_id);
292		goto failed;
293	}
294
295	/*
296	 * Open channel w/ the bufring GPADL on the target CPU.
297	 */
298	mh = vmbus_msghc_get(sc, sizeof(*req));
299	if (mh == NULL) {
300		device_printf(sc->vmbus_dev,
301		    "can not get msg hypercall for chopen(chan%u)\n",
302		    chan->ch_id);
303		error = ENXIO;
304		goto failed;
305	}
306
307	req = vmbus_msghc_dataptr(mh);
308	req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_CHOPEN;
309	req->chm_chanid = chan->ch_id;
310	req->chm_openid = chan->ch_id;
311	req->chm_gpadl = chan->ch_bufring_gpadl;
312	req->chm_vcpuid = chan->ch_vcpuid;
313	req->chm_txbr_pgcnt = txbr_size >> PAGE_SHIFT;
314	if (udlen > 0)
315		memcpy(req->chm_udata, udata, udlen);
316
317	error = vmbus_msghc_exec(sc, mh);
318	if (error) {
319		device_printf(sc->vmbus_dev,
320		    "chopen(chan%u) msg hypercall exec failed: %d\n",
321		    chan->ch_id, error);
322		vmbus_msghc_put(sc, mh);
323		goto failed;
324	}
325
326	msg = vmbus_msghc_wait_result(sc, mh);
327	resp = (const struct vmbus_chanmsg_chopen_resp *)msg->msg_data;
328	status = resp->chm_status;
329
330	vmbus_msghc_put(sc, mh);
331
332	if (status == 0) {
333		if (bootverbose) {
334			device_printf(sc->vmbus_dev, "chan%u opened\n",
335			    chan->ch_id);
336		}
337		return 0;
338	}
339
340	device_printf(sc->vmbus_dev, "failed to open chan%u\n", chan->ch_id);
341	error = ENXIO;
342
343failed:
344	if (chan->ch_bufring_gpadl) {
345		vmbus_chan_gpadl_disconnect(chan, chan->ch_bufring_gpadl);
346		chan->ch_bufring_gpadl = 0;
347	}
348	atomic_clear_int(&chan->ch_stflags, VMBUS_CHAN_ST_OPENED);
349	return error;
350}
351
352int
353vmbus_chan_gpadl_connect(struct vmbus_channel *chan, bus_addr_t paddr,
354    int size, uint32_t *gpadl0)
355{
356	struct vmbus_softc *sc = chan->ch_vmbus;
357	struct vmbus_msghc *mh;
358	struct vmbus_chanmsg_gpadl_conn *req;
359	const struct vmbus_message *msg;
360	size_t reqsz;
361	uint32_t gpadl, status;
362	int page_count, range_len, i, cnt, error;
363	uint64_t page_id;
364
365	/*
366	 * Preliminary checks.
367	 */
368
369	KASSERT((size & PAGE_MASK) == 0,
370	    ("invalid GPA size %d, not multiple page size", size));
371	page_count = size >> PAGE_SHIFT;
372
373	KASSERT((paddr & PAGE_MASK) == 0,
374	    ("GPA is not page aligned %jx", (uintmax_t)paddr));
375	page_id = paddr >> PAGE_SHIFT;
376
377	range_len = __offsetof(struct vmbus_gpa_range, gpa_page[page_count]);
378	/*
379	 * We don't support multiple GPA ranges.
380	 */
381	if (range_len > UINT16_MAX) {
382		device_printf(sc->vmbus_dev, "GPA too large, %d pages\n",
383		    page_count);
384		return EOPNOTSUPP;
385	}
386
387	/*
388	 * Allocate GPADL id.
389	 */
390	gpadl = vmbus_gpadl_alloc(sc);
391	*gpadl0 = gpadl;
392
393	/*
394	 * Connect this GPADL to the target channel.
395	 *
396	 * NOTE:
397	 * Since each message can only hold small set of page
398	 * addresses, several messages may be required to
399	 * complete the connection.
400	 */
401	if (page_count > VMBUS_CHANMSG_GPADL_CONN_PGMAX)
402		cnt = VMBUS_CHANMSG_GPADL_CONN_PGMAX;
403	else
404		cnt = page_count;
405	page_count -= cnt;
406
407	reqsz = __offsetof(struct vmbus_chanmsg_gpadl_conn,
408	    chm_range.gpa_page[cnt]);
409	mh = vmbus_msghc_get(sc, reqsz);
410	if (mh == NULL) {
411		device_printf(sc->vmbus_dev,
412		    "can not get msg hypercall for gpadl->chan%u\n",
413		    chan->ch_id);
414		return EIO;
415	}
416
417	req = vmbus_msghc_dataptr(mh);
418	req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_GPADL_CONN;
419	req->chm_chanid = chan->ch_id;
420	req->chm_gpadl = gpadl;
421	req->chm_range_len = range_len;
422	req->chm_range_cnt = 1;
423	req->chm_range.gpa_len = size;
424	req->chm_range.gpa_ofs = 0;
425	for (i = 0; i < cnt; ++i)
426		req->chm_range.gpa_page[i] = page_id++;
427
428	error = vmbus_msghc_exec(sc, mh);
429	if (error) {
430		device_printf(sc->vmbus_dev,
431		    "gpadl->chan%u msg hypercall exec failed: %d\n",
432		    chan->ch_id, error);
433		vmbus_msghc_put(sc, mh);
434		return error;
435	}
436
437	while (page_count > 0) {
438		struct vmbus_chanmsg_gpadl_subconn *subreq;
439
440		if (page_count > VMBUS_CHANMSG_GPADL_SUBCONN_PGMAX)
441			cnt = VMBUS_CHANMSG_GPADL_SUBCONN_PGMAX;
442		else
443			cnt = page_count;
444		page_count -= cnt;
445
446		reqsz = __offsetof(struct vmbus_chanmsg_gpadl_subconn,
447		    chm_gpa_page[cnt]);
448		vmbus_msghc_reset(mh, reqsz);
449
450		subreq = vmbus_msghc_dataptr(mh);
451		subreq->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_GPADL_SUBCONN;
452		subreq->chm_gpadl = gpadl;
453		for (i = 0; i < cnt; ++i)
454			subreq->chm_gpa_page[i] = page_id++;
455
456		vmbus_msghc_exec_noresult(mh);
457	}
458	KASSERT(page_count == 0, ("invalid page count %d", page_count));
459
460	msg = vmbus_msghc_wait_result(sc, mh);
461	status = ((const struct vmbus_chanmsg_gpadl_connresp *)
462	    msg->msg_data)->chm_status;
463
464	vmbus_msghc_put(sc, mh);
465
466	if (status != 0) {
467		device_printf(sc->vmbus_dev, "gpadl->chan%u failed: "
468		    "status %u\n", chan->ch_id, status);
469		return EIO;
470	} else {
471		if (bootverbose) {
472			device_printf(sc->vmbus_dev, "gpadl->chan%u "
473			    "succeeded\n", chan->ch_id);
474		}
475	}
476	return 0;
477}
478
479/*
480 * Disconnect the GPA from the target channel
481 */
482int
483vmbus_chan_gpadl_disconnect(struct vmbus_channel *chan, uint32_t gpadl)
484{
485	struct vmbus_softc *sc = chan->ch_vmbus;
486	struct vmbus_msghc *mh;
487	struct vmbus_chanmsg_gpadl_disconn *req;
488	int error;
489
490	mh = vmbus_msghc_get(sc, sizeof(*req));
491	if (mh == NULL) {
492		device_printf(sc->vmbus_dev,
493		    "can not get msg hypercall for gpa x->chan%u\n",
494		    chan->ch_id);
495		return EBUSY;
496	}
497
498	req = vmbus_msghc_dataptr(mh);
499	req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_GPADL_DISCONN;
500	req->chm_chanid = chan->ch_id;
501	req->chm_gpadl = gpadl;
502
503	error = vmbus_msghc_exec(sc, mh);
504	if (error) {
505		device_printf(sc->vmbus_dev,
506		    "gpa x->chan%u msg hypercall exec failed: %d\n",
507		    chan->ch_id, error);
508		vmbus_msghc_put(sc, mh);
509		return error;
510	}
511
512	vmbus_msghc_wait_result(sc, mh);
513	/* Discard result; no useful information */
514	vmbus_msghc_put(sc, mh);
515
516	return 0;
517}
518
519static void
520vmbus_chan_close_internal(struct vmbus_channel *chan)
521{
522	struct vmbus_softc *sc = chan->ch_vmbus;
523	struct vmbus_msghc *mh;
524	struct vmbus_chanmsg_chclose *req;
525	struct taskqueue *tq = chan->ch_tq;
526	int error;
527
528	/* TODO: stringent check */
529	atomic_clear_int(&chan->ch_stflags, VMBUS_CHAN_ST_OPENED);
530
531	/*
532	 * Free this channel's sysctl tree attached to its device's
533	 * sysctl tree.
534	 */
535	sysctl_ctx_free(&chan->ch_sysctl_ctx);
536
537	/*
538	 * Set ch_tq to NULL to avoid more requests be scheduled.
539	 * XXX pretty broken; need rework.
540	 */
541	chan->ch_tq = NULL;
542	taskqueue_drain(tq, &chan->ch_task);
543	chan->ch_cb = NULL;
544
545	/*
546	 * Close this channel.
547	 */
548	mh = vmbus_msghc_get(sc, sizeof(*req));
549	if (mh == NULL) {
550		device_printf(sc->vmbus_dev,
551		    "can not get msg hypercall for chclose(chan%u)\n",
552		    chan->ch_id);
553		return;
554	}
555
556	req = vmbus_msghc_dataptr(mh);
557	req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_CHCLOSE;
558	req->chm_chanid = chan->ch_id;
559
560	error = vmbus_msghc_exec_noresult(mh);
561	vmbus_msghc_put(sc, mh);
562
563	if (error) {
564		device_printf(sc->vmbus_dev,
565		    "chclose(chan%u) msg hypercall exec failed: %d\n",
566		    chan->ch_id, error);
567		return;
568	} else if (bootverbose) {
569		device_printf(sc->vmbus_dev, "close chan%u\n", chan->ch_id);
570	}
571
572	/*
573	 * Disconnect the TX+RX bufrings from this channel.
574	 */
575	if (chan->ch_bufring_gpadl) {
576		vmbus_chan_gpadl_disconnect(chan, chan->ch_bufring_gpadl);
577		chan->ch_bufring_gpadl = 0;
578	}
579
580	/*
581	 * Destroy the TX+RX bufrings.
582	 */
583	if (chan->ch_bufring != NULL) {
584		hyperv_dmamem_free(&chan->ch_bufring_dma, chan->ch_bufring);
585		chan->ch_bufring = NULL;
586	}
587}
588
589/*
590 * Caller should make sure that all sub-channels have
591 * been added to 'chan' and all to-be-closed channels
592 * are not being opened.
593 */
594void
595vmbus_chan_close(struct vmbus_channel *chan)
596{
597	int subchan_cnt;
598
599	if (!VMBUS_CHAN_ISPRIMARY(chan)) {
600		/*
601		 * Sub-channel is closed when its primary channel
602		 * is closed; done.
603		 */
604		return;
605	}
606
607	/*
608	 * Close all sub-channels, if any.
609	 */
610	subchan_cnt = chan->ch_subchan_cnt;
611	if (subchan_cnt > 0) {
612		struct vmbus_channel **subchan;
613		int i;
614
615		subchan = vmbus_subchan_get(chan, subchan_cnt);
616		for (i = 0; i < subchan_cnt; ++i)
617			vmbus_chan_close_internal(subchan[i]);
618		vmbus_subchan_rel(subchan, subchan_cnt);
619	}
620
621	/* Then close the primary channel. */
622	vmbus_chan_close_internal(chan);
623}
624
625int
626vmbus_chan_send(struct vmbus_channel *chan, uint16_t type, uint16_t flags,
627    void *data, int dlen, uint64_t xactid)
628{
629	struct vmbus_chanpkt pkt;
630	int pktlen, pad_pktlen, hlen, error;
631	uint64_t pad = 0;
632	struct iovec iov[3];
633	boolean_t send_evt;
634
635	hlen = sizeof(pkt);
636	pktlen = hlen + dlen;
637	pad_pktlen = VMBUS_CHANPKT_TOTLEN(pktlen);
638	KASSERT(pad_pktlen <= vmbus_txbr_maxpktsz(&chan->ch_txbr),
639	    ("invalid packet size %d", pad_pktlen));
640
641	pkt.cp_hdr.cph_type = type;
642	pkt.cp_hdr.cph_flags = flags;
643	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_hlen, hlen);
644	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_tlen, pad_pktlen);
645	pkt.cp_hdr.cph_xactid = xactid;
646
647	iov[0].iov_base = &pkt;
648	iov[0].iov_len = hlen;
649	iov[1].iov_base = data;
650	iov[1].iov_len = dlen;
651	iov[2].iov_base = &pad;
652	iov[2].iov_len = pad_pktlen - pktlen;
653
654	error = vmbus_txbr_write(&chan->ch_txbr, iov, 3, &send_evt);
655	if (!error && send_evt)
656		vmbus_chan_signal_tx(chan);
657	return error;
658}
659
660int
661vmbus_chan_send_sglist(struct vmbus_channel *chan,
662    struct vmbus_gpa sg[], int sglen, void *data, int dlen, uint64_t xactid)
663{
664	struct vmbus_chanpkt_sglist pkt;
665	int pktlen, pad_pktlen, hlen, error;
666	struct iovec iov[4];
667	boolean_t send_evt;
668	uint64_t pad = 0;
669
670	hlen = __offsetof(struct vmbus_chanpkt_sglist, cp_gpa[sglen]);
671	pktlen = hlen + dlen;
672	pad_pktlen = VMBUS_CHANPKT_TOTLEN(pktlen);
673	KASSERT(pad_pktlen <= vmbus_txbr_maxpktsz(&chan->ch_txbr),
674	    ("invalid packet size %d", pad_pktlen));
675
676	pkt.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
677	pkt.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
678	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_hlen, hlen);
679	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_tlen, pad_pktlen);
680	pkt.cp_hdr.cph_xactid = xactid;
681	pkt.cp_rsvd = 0;
682	pkt.cp_gpa_cnt = sglen;
683
684	iov[0].iov_base = &pkt;
685	iov[0].iov_len = sizeof(pkt);
686	iov[1].iov_base = sg;
687	iov[1].iov_len = sizeof(struct vmbus_gpa) * sglen;
688	iov[2].iov_base = data;
689	iov[2].iov_len = dlen;
690	iov[3].iov_base = &pad;
691	iov[3].iov_len = pad_pktlen - pktlen;
692
693	error = vmbus_txbr_write(&chan->ch_txbr, iov, 4, &send_evt);
694	if (!error && send_evt)
695		vmbus_chan_signal_tx(chan);
696	return error;
697}
698
699int
700vmbus_chan_send_prplist(struct vmbus_channel *chan,
701    struct vmbus_gpa_range *prp, int prp_cnt, void *data, int dlen,
702    uint64_t xactid)
703{
704	struct vmbus_chanpkt_prplist pkt;
705	int pktlen, pad_pktlen, hlen, error;
706	struct iovec iov[4];
707	boolean_t send_evt;
708	uint64_t pad = 0;
709
710	hlen = __offsetof(struct vmbus_chanpkt_prplist,
711	    cp_range[0].gpa_page[prp_cnt]);
712	pktlen = hlen + dlen;
713	pad_pktlen = VMBUS_CHANPKT_TOTLEN(pktlen);
714	KASSERT(pad_pktlen <= vmbus_txbr_maxpktsz(&chan->ch_txbr),
715	    ("invalid packet size %d", pad_pktlen));
716
717	pkt.cp_hdr.cph_type = VMBUS_CHANPKT_TYPE_GPA;
718	pkt.cp_hdr.cph_flags = VMBUS_CHANPKT_FLAG_RC;
719	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_hlen, hlen);
720	VMBUS_CHANPKT_SETLEN(pkt.cp_hdr.cph_tlen, pad_pktlen);
721	pkt.cp_hdr.cph_xactid = xactid;
722	pkt.cp_rsvd = 0;
723	pkt.cp_range_cnt = 1;
724
725	iov[0].iov_base = &pkt;
726	iov[0].iov_len = sizeof(pkt);
727	iov[1].iov_base = prp;
728	iov[1].iov_len = __offsetof(struct vmbus_gpa_range, gpa_page[prp_cnt]);
729	iov[2].iov_base = data;
730	iov[2].iov_len = dlen;
731	iov[3].iov_base = &pad;
732	iov[3].iov_len = pad_pktlen - pktlen;
733
734	error = vmbus_txbr_write(&chan->ch_txbr, iov, 4, &send_evt);
735	if (!error && send_evt)
736		vmbus_chan_signal_tx(chan);
737	return error;
738}
739
740int
741vmbus_chan_recv(struct vmbus_channel *chan, void *data, int *dlen0,
742    uint64_t *xactid)
743{
744	struct vmbus_chanpkt_hdr pkt;
745	int error, dlen, hlen;
746
747	error = vmbus_rxbr_peek(&chan->ch_rxbr, &pkt, sizeof(pkt));
748	if (error)
749		return (error);
750
751	if (__predict_false(pkt.cph_hlen < VMBUS_CHANPKT_HLEN_MIN)) {
752		device_printf(chan->ch_dev, "invalid hlen %u\n",
753		    pkt.cph_hlen);
754		/* XXX this channel is dead actually. */
755		return (EIO);
756	}
757	if (__predict_false(pkt.cph_hlen > pkt.cph_tlen)) {
758		device_printf(chan->ch_dev, "invalid hlen %u and tlen %u\n",
759		    pkt.cph_hlen, pkt.cph_tlen);
760		/* XXX this channel is dead actually. */
761		return (EIO);
762	}
763
764	hlen = VMBUS_CHANPKT_GETLEN(pkt.cph_hlen);
765	dlen = VMBUS_CHANPKT_GETLEN(pkt.cph_tlen) - hlen;
766
767	if (*dlen0 < dlen) {
768		/* Return the size of this packet's data. */
769		*dlen0 = dlen;
770		return (ENOBUFS);
771	}
772
773	*xactid = pkt.cph_xactid;
774	*dlen0 = dlen;
775
776	/* Skip packet header */
777	error = vmbus_rxbr_read(&chan->ch_rxbr, data, dlen, hlen);
778	KASSERT(!error, ("vmbus_rxbr_read failed"));
779
780	return (0);
781}
782
783int
784vmbus_chan_recv_pkt(struct vmbus_channel *chan,
785    struct vmbus_chanpkt_hdr *pkt0, int *pktlen0)
786{
787	struct vmbus_chanpkt_hdr pkt;
788	int error, pktlen;
789
790	error = vmbus_rxbr_peek(&chan->ch_rxbr, &pkt, sizeof(pkt));
791	if (error)
792		return (error);
793
794	if (__predict_false(pkt.cph_hlen < VMBUS_CHANPKT_HLEN_MIN)) {
795		device_printf(chan->ch_dev, "invalid hlen %u\n",
796		    pkt.cph_hlen);
797		/* XXX this channel is dead actually. */
798		return (EIO);
799	}
800	if (__predict_false(pkt.cph_hlen > pkt.cph_tlen)) {
801		device_printf(chan->ch_dev, "invalid hlen %u and tlen %u\n",
802		    pkt.cph_hlen, pkt.cph_tlen);
803		/* XXX this channel is dead actually. */
804		return (EIO);
805	}
806
807	pktlen = VMBUS_CHANPKT_GETLEN(pkt.cph_tlen);
808	if (*pktlen0 < pktlen) {
809		/* Return the size of this packet. */
810		*pktlen0 = pktlen;
811		return (ENOBUFS);
812	}
813	*pktlen0 = pktlen;
814
815	/* Include packet header */
816	error = vmbus_rxbr_read(&chan->ch_rxbr, pkt0, pktlen, 0);
817	KASSERT(!error, ("vmbus_rxbr_read failed"));
818
819	return (0);
820}
821
822static void
823vmbus_chan_task(void *xchan, int pending __unused)
824{
825	struct vmbus_channel *chan = xchan;
826	vmbus_chan_callback_t cb = chan->ch_cb;
827	void *cbarg = chan->ch_cbarg;
828
829	/*
830	 * Optimize host to guest signaling by ensuring:
831	 * 1. While reading the channel, we disable interrupts from
832	 *    host.
833	 * 2. Ensure that we process all posted messages from the host
834	 *    before returning from this callback.
835	 * 3. Once we return, enable signaling from the host. Once this
836	 *    state is set we check to see if additional packets are
837	 *    available to read. In this case we repeat the process.
838	 *
839	 * NOTE: Interrupt has been disabled in the ISR.
840	 */
841	for (;;) {
842		uint32_t left;
843
844		cb(chan, cbarg);
845
846		left = vmbus_rxbr_intr_unmask(&chan->ch_rxbr);
847		if (left == 0) {
848			/* No more data in RX bufring; done */
849			break;
850		}
851		vmbus_rxbr_intr_mask(&chan->ch_rxbr);
852	}
853}
854
855static void
856vmbus_chan_task_nobatch(void *xchan, int pending __unused)
857{
858	struct vmbus_channel *chan = xchan;
859
860	chan->ch_cb(chan, chan->ch_cbarg);
861}
862
863static __inline void
864vmbus_event_flags_proc(struct vmbus_softc *sc, volatile u_long *event_flags,
865    int flag_cnt)
866{
867	int f;
868
869	for (f = 0; f < flag_cnt; ++f) {
870		uint32_t chid_base;
871		u_long flags;
872		int chid_ofs;
873
874		if (event_flags[f] == 0)
875			continue;
876
877		flags = atomic_swap_long(&event_flags[f], 0);
878		chid_base = f << VMBUS_EVTFLAG_SHIFT;
879
880		while ((chid_ofs = ffsl(flags)) != 0) {
881			struct vmbus_channel *chan;
882
883			--chid_ofs; /* NOTE: ffsl is 1-based */
884			flags &= ~(1UL << chid_ofs);
885
886			chan = sc->vmbus_chmap[chid_base + chid_ofs];
887
888			/* if channel is closed or closing */
889			if (chan == NULL || chan->ch_tq == NULL)
890				continue;
891
892			if (chan->ch_flags & VMBUS_CHAN_FLAG_BATCHREAD)
893				vmbus_rxbr_intr_mask(&chan->ch_rxbr);
894			taskqueue_enqueue(chan->ch_tq, &chan->ch_task);
895		}
896	}
897}
898
899void
900vmbus_event_proc(struct vmbus_softc *sc, int cpu)
901{
902	struct vmbus_evtflags *eventf;
903
904	/*
905	 * On Host with Win8 or above, the event page can be checked directly
906	 * to get the id of the channel that has the pending interrupt.
907	 */
908	eventf = VMBUS_PCPU_GET(sc, event_flags, cpu) + VMBUS_SINT_MESSAGE;
909	vmbus_event_flags_proc(sc, eventf->evt_flags,
910	    VMBUS_PCPU_GET(sc, event_flags_cnt, cpu));
911}
912
913void
914vmbus_event_proc_compat(struct vmbus_softc *sc, int cpu)
915{
916	struct vmbus_evtflags *eventf;
917
918	eventf = VMBUS_PCPU_GET(sc, event_flags, cpu) + VMBUS_SINT_MESSAGE;
919	if (atomic_testandclear_long(&eventf->evt_flags[0], 0)) {
920		vmbus_event_flags_proc(sc, sc->vmbus_rx_evtflags,
921		    VMBUS_CHAN_MAX_COMPAT >> VMBUS_EVTFLAG_SHIFT);
922	}
923}
924
925static void
926vmbus_chan_update_evtflagcnt(struct vmbus_softc *sc,
927    const struct vmbus_channel *chan)
928{
929	volatile int *flag_cnt_ptr;
930	int flag_cnt;
931
932	flag_cnt = (chan->ch_id / VMBUS_EVTFLAG_LEN) + 1;
933	flag_cnt_ptr = VMBUS_PCPU_PTR(sc, event_flags_cnt, chan->ch_cpuid);
934
935	for (;;) {
936		int old_flag_cnt;
937
938		old_flag_cnt = *flag_cnt_ptr;
939		if (old_flag_cnt >= flag_cnt)
940			break;
941		if (atomic_cmpset_int(flag_cnt_ptr, old_flag_cnt, flag_cnt)) {
942			if (bootverbose) {
943				device_printf(sc->vmbus_dev,
944				    "channel%u update cpu%d flag_cnt to %d\n",
945				    chan->ch_id, chan->ch_cpuid, flag_cnt);
946			}
947			break;
948		}
949	}
950}
951
952static struct vmbus_channel *
953vmbus_chan_alloc(struct vmbus_softc *sc)
954{
955	struct vmbus_channel *chan;
956
957	chan = malloc(sizeof(*chan), M_DEVBUF, M_WAITOK | M_ZERO);
958
959	chan->ch_monprm = hyperv_dmamem_alloc(bus_get_dma_tag(sc->vmbus_dev),
960	    HYPERCALL_PARAM_ALIGN, 0, sizeof(struct hyperv_mon_param),
961	    &chan->ch_monprm_dma, BUS_DMA_WAITOK | BUS_DMA_ZERO);
962	if (chan->ch_monprm == NULL) {
963		device_printf(sc->vmbus_dev, "monprm alloc failed\n");
964		free(chan, M_DEVBUF);
965		return NULL;
966	}
967
968	chan->ch_vmbus = sc;
969	mtx_init(&chan->ch_subchan_lock, "vmbus subchan", NULL, MTX_DEF);
970	TAILQ_INIT(&chan->ch_subchans);
971	TASK_INIT(&chan->ch_detach_task, 0, vmbus_chan_detach_task, chan);
972	vmbus_rxbr_init(&chan->ch_rxbr);
973	vmbus_txbr_init(&chan->ch_txbr);
974
975	return chan;
976}
977
978static void
979vmbus_chan_free(struct vmbus_channel *chan)
980{
981	/* TODO: assert sub-channel list is empty */
982	/* TODO: asset no longer on the primary channel's sub-channel list */
983	/* TODO: asset no longer on the vmbus channel list */
984	hyperv_dmamem_free(&chan->ch_monprm_dma, chan->ch_monprm);
985	mtx_destroy(&chan->ch_subchan_lock);
986	vmbus_rxbr_deinit(&chan->ch_rxbr);
987	vmbus_txbr_deinit(&chan->ch_txbr);
988	free(chan, M_DEVBUF);
989}
990
991static int
992vmbus_chan_add(struct vmbus_channel *newchan)
993{
994	struct vmbus_softc *sc = newchan->ch_vmbus;
995	struct vmbus_channel *prichan;
996
997	if (newchan->ch_id == 0) {
998		/*
999		 * XXX
1000		 * Chan0 will neither be processed nor should be offered;
1001		 * skip it.
1002		 */
1003		device_printf(sc->vmbus_dev, "got chan0 offer, discard\n");
1004		return EINVAL;
1005	} else if (newchan->ch_id >= VMBUS_CHAN_MAX) {
1006		device_printf(sc->vmbus_dev, "invalid chan%u offer\n",
1007		    newchan->ch_id);
1008		return EINVAL;
1009	}
1010	sc->vmbus_chmap[newchan->ch_id] = newchan;
1011
1012	if (bootverbose) {
1013		device_printf(sc->vmbus_dev, "chan%u subidx%u offer\n",
1014		    newchan->ch_id, newchan->ch_subidx);
1015	}
1016
1017	mtx_lock(&sc->vmbus_prichan_lock);
1018	TAILQ_FOREACH(prichan, &sc->vmbus_prichans, ch_prilink) {
1019		/*
1020		 * Sub-channel will have the same type GUID and instance
1021		 * GUID as its primary channel.
1022		 */
1023		if (memcmp(&prichan->ch_guid_type, &newchan->ch_guid_type,
1024		    sizeof(struct hyperv_guid)) == 0 &&
1025		    memcmp(&prichan->ch_guid_inst, &newchan->ch_guid_inst,
1026		    sizeof(struct hyperv_guid)) == 0)
1027			break;
1028	}
1029	if (VMBUS_CHAN_ISPRIMARY(newchan)) {
1030		if (prichan == NULL) {
1031			/* Install the new primary channel */
1032			TAILQ_INSERT_TAIL(&sc->vmbus_prichans, newchan,
1033			    ch_prilink);
1034			mtx_unlock(&sc->vmbus_prichan_lock);
1035			return 0;
1036		} else {
1037			mtx_unlock(&sc->vmbus_prichan_lock);
1038			device_printf(sc->vmbus_dev, "duplicated primary "
1039			    "chan%u\n", newchan->ch_id);
1040			return EINVAL;
1041		}
1042	} else { /* Sub-channel */
1043		if (prichan == NULL) {
1044			mtx_unlock(&sc->vmbus_prichan_lock);
1045			device_printf(sc->vmbus_dev, "no primary chan for "
1046			    "chan%u\n", newchan->ch_id);
1047			return EINVAL;
1048		}
1049		/*
1050		 * Found the primary channel for this sub-channel and
1051		 * move on.
1052		 *
1053		 * XXX refcnt prichan
1054		 */
1055	}
1056	mtx_unlock(&sc->vmbus_prichan_lock);
1057
1058	/*
1059	 * This is a sub-channel; link it with the primary channel.
1060	 */
1061	KASSERT(!VMBUS_CHAN_ISPRIMARY(newchan),
1062	    ("new channel is not sub-channel"));
1063	KASSERT(prichan != NULL, ("no primary channel"));
1064
1065	newchan->ch_prichan = prichan;
1066	newchan->ch_dev = prichan->ch_dev;
1067
1068	mtx_lock(&prichan->ch_subchan_lock);
1069	TAILQ_INSERT_TAIL(&prichan->ch_subchans, newchan, ch_sublink);
1070	/*
1071	 * Bump up sub-channel count and notify anyone that is
1072	 * interested in this sub-channel, after this sub-channel
1073	 * is setup.
1074	 */
1075	prichan->ch_subchan_cnt++;
1076	mtx_unlock(&prichan->ch_subchan_lock);
1077	wakeup(prichan);
1078
1079	return 0;
1080}
1081
1082void
1083vmbus_chan_cpu_set(struct vmbus_channel *chan, int cpu)
1084{
1085	KASSERT(cpu >= 0 && cpu < mp_ncpus, ("invalid cpu %d", cpu));
1086
1087	if (chan->ch_vmbus->vmbus_version == VMBUS_VERSION_WS2008 ||
1088	    chan->ch_vmbus->vmbus_version == VMBUS_VERSION_WIN7) {
1089		/* Only cpu0 is supported */
1090		cpu = 0;
1091	}
1092
1093	chan->ch_cpuid = cpu;
1094	chan->ch_vcpuid = VMBUS_PCPU_GET(chan->ch_vmbus, vcpuid, cpu);
1095
1096	if (bootverbose) {
1097		printf("vmbus_chan%u: assigned to cpu%u [vcpu%u]\n",
1098		    chan->ch_id, chan->ch_cpuid, chan->ch_vcpuid);
1099	}
1100}
1101
1102void
1103vmbus_chan_cpu_rr(struct vmbus_channel *chan)
1104{
1105	static uint32_t vmbus_chan_nextcpu;
1106	int cpu;
1107
1108	cpu = atomic_fetchadd_int(&vmbus_chan_nextcpu, 1) % mp_ncpus;
1109	vmbus_chan_cpu_set(chan, cpu);
1110}
1111
1112static void
1113vmbus_chan_cpu_default(struct vmbus_channel *chan)
1114{
1115	/*
1116	 * By default, pin the channel to cpu0.  Devices having
1117	 * special channel-cpu mapping requirement should call
1118	 * vmbus_chan_cpu_{set,rr}().
1119	 */
1120	vmbus_chan_cpu_set(chan, 0);
1121}
1122
1123static void
1124vmbus_chan_msgproc_choffer(struct vmbus_softc *sc,
1125    const struct vmbus_message *msg)
1126{
1127	const struct vmbus_chanmsg_choffer *offer;
1128	struct vmbus_channel *chan;
1129	int error;
1130
1131	offer = (const struct vmbus_chanmsg_choffer *)msg->msg_data;
1132
1133	chan = vmbus_chan_alloc(sc);
1134	if (chan == NULL) {
1135		device_printf(sc->vmbus_dev, "allocate chan%u failed\n",
1136		    offer->chm_chanid);
1137		return;
1138	}
1139
1140	chan->ch_id = offer->chm_chanid;
1141	chan->ch_subidx = offer->chm_subidx;
1142	chan->ch_guid_type = offer->chm_chtype;
1143	chan->ch_guid_inst = offer->chm_chinst;
1144
1145	/* Batch reading is on by default */
1146	chan->ch_flags |= VMBUS_CHAN_FLAG_BATCHREAD;
1147
1148	chan->ch_monprm->mp_connid = VMBUS_CONNID_EVENT;
1149	if (sc->vmbus_version != VMBUS_VERSION_WS2008)
1150		chan->ch_monprm->mp_connid = offer->chm_connid;
1151
1152	if (offer->chm_flags1 & VMBUS_CHOFFER_FLAG1_HASMNF) {
1153		int trig_idx;
1154
1155		/*
1156		 * Setup MNF stuffs.
1157		 */
1158		chan->ch_txflags |= VMBUS_CHAN_TXF_HASMNF;
1159
1160		trig_idx = offer->chm_montrig / VMBUS_MONTRIG_LEN;
1161		if (trig_idx >= VMBUS_MONTRIGS_MAX)
1162			panic("invalid monitor trigger %u", offer->chm_montrig);
1163		chan->ch_montrig =
1164		    &sc->vmbus_mnf2->mnf_trigs[trig_idx].mt_pending;
1165
1166		chan->ch_montrig_mask =
1167		    1 << (offer->chm_montrig % VMBUS_MONTRIG_LEN);
1168	}
1169
1170	/*
1171	 * Setup event flag.
1172	 */
1173	chan->ch_evtflag =
1174	    &sc->vmbus_tx_evtflags[chan->ch_id >> VMBUS_EVTFLAG_SHIFT];
1175	chan->ch_evtflag_mask = 1UL << (chan->ch_id & VMBUS_EVTFLAG_MASK);
1176
1177	/* Select default cpu for this channel. */
1178	vmbus_chan_cpu_default(chan);
1179
1180	error = vmbus_chan_add(chan);
1181	if (error) {
1182		device_printf(sc->vmbus_dev, "add chan%u failed: %d\n",
1183		    chan->ch_id, error);
1184		vmbus_chan_free(chan);
1185		return;
1186	}
1187
1188	if (VMBUS_CHAN_ISPRIMARY(chan)) {
1189		/*
1190		 * Add device for this primary channel.
1191		 *
1192		 * NOTE:
1193		 * Error is ignored here; don't have much to do if error
1194		 * really happens.
1195		 */
1196		vmbus_add_child(chan);
1197	}
1198}
1199
1200/*
1201 * XXX pretty broken; need rework.
1202 */
1203static void
1204vmbus_chan_msgproc_chrescind(struct vmbus_softc *sc,
1205    const struct vmbus_message *msg)
1206{
1207	const struct vmbus_chanmsg_chrescind *note;
1208	struct vmbus_channel *chan;
1209
1210	note = (const struct vmbus_chanmsg_chrescind *)msg->msg_data;
1211	if (note->chm_chanid > VMBUS_CHAN_MAX) {
1212		device_printf(sc->vmbus_dev, "invalid rescinded chan%u\n",
1213		    note->chm_chanid);
1214		return;
1215	}
1216
1217	if (bootverbose) {
1218		device_printf(sc->vmbus_dev, "chan%u rescinded\n",
1219		    note->chm_chanid);
1220	}
1221
1222	chan = sc->vmbus_chmap[note->chm_chanid];
1223	if (chan == NULL)
1224		return;
1225	sc->vmbus_chmap[note->chm_chanid] = NULL;
1226
1227	taskqueue_enqueue(taskqueue_thread, &chan->ch_detach_task);
1228}
1229
1230static void
1231vmbus_chan_detach_task(void *xchan, int pending __unused)
1232{
1233	struct vmbus_channel *chan = xchan;
1234
1235	if (VMBUS_CHAN_ISPRIMARY(chan)) {
1236		/* Only primary channel owns the device */
1237		vmbus_delete_child(chan);
1238		/* NOTE: DO NOT free primary channel for now */
1239	} else {
1240		struct vmbus_softc *sc = chan->ch_vmbus;
1241		struct vmbus_channel *pri_chan = chan->ch_prichan;
1242		struct vmbus_chanmsg_chfree *req;
1243		struct vmbus_msghc *mh;
1244		int error;
1245
1246		mh = vmbus_msghc_get(sc, sizeof(*req));
1247		if (mh == NULL) {
1248			device_printf(sc->vmbus_dev,
1249			    "can not get msg hypercall for chfree(chan%u)\n",
1250			    chan->ch_id);
1251			goto remove;
1252		}
1253
1254		req = vmbus_msghc_dataptr(mh);
1255		req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_CHFREE;
1256		req->chm_chanid = chan->ch_id;
1257
1258		error = vmbus_msghc_exec_noresult(mh);
1259		vmbus_msghc_put(sc, mh);
1260
1261		if (error) {
1262			device_printf(sc->vmbus_dev,
1263			    "chfree(chan%u) failed: %d",
1264			    chan->ch_id, error);
1265			/* NOTE: Move on! */
1266		} else {
1267			if (bootverbose) {
1268				device_printf(sc->vmbus_dev, "chan%u freed\n",
1269				    chan->ch_id);
1270			}
1271		}
1272remove:
1273		mtx_lock(&pri_chan->ch_subchan_lock);
1274		TAILQ_REMOVE(&pri_chan->ch_subchans, chan, ch_sublink);
1275		KASSERT(pri_chan->ch_subchan_cnt > 0,
1276		    ("invalid subchan_cnt %d", pri_chan->ch_subchan_cnt));
1277		pri_chan->ch_subchan_cnt--;
1278		mtx_unlock(&pri_chan->ch_subchan_lock);
1279		wakeup(pri_chan);
1280
1281		vmbus_chan_free(chan);
1282	}
1283}
1284
1285/*
1286 * Detach all devices and destroy the corresponding primary channels.
1287 */
1288void
1289vmbus_chan_destroy_all(struct vmbus_softc *sc)
1290{
1291	struct vmbus_channel *chan;
1292
1293	mtx_lock(&sc->vmbus_prichan_lock);
1294	while ((chan = TAILQ_FIRST(&sc->vmbus_prichans)) != NULL) {
1295		KASSERT(VMBUS_CHAN_ISPRIMARY(chan), ("not primary channel"));
1296		TAILQ_REMOVE(&sc->vmbus_prichans, chan, ch_prilink);
1297		mtx_unlock(&sc->vmbus_prichan_lock);
1298
1299		vmbus_delete_child(chan);
1300		vmbus_chan_free(chan);
1301
1302		mtx_lock(&sc->vmbus_prichan_lock);
1303	}
1304	bzero(sc->vmbus_chmap,
1305	    sizeof(struct vmbus_channel *) * VMBUS_CHAN_MAX);
1306	mtx_unlock(&sc->vmbus_prichan_lock);
1307}
1308
1309/*
1310 * The channel whose vcpu binding is closest to the currect vcpu will
1311 * be selected.
1312 * If no multi-channel, always select primary channel.
1313 */
1314struct vmbus_channel *
1315vmbus_chan_cpu2chan(struct vmbus_channel *prichan, int cpu)
1316{
1317	struct vmbus_channel *sel, *chan;
1318	uint32_t vcpu, sel_dist;
1319
1320	KASSERT(cpu >= 0 && cpu < mp_ncpus, ("invalid cpuid %d", cpu));
1321	if (TAILQ_EMPTY(&prichan->ch_subchans))
1322		return prichan;
1323
1324	vcpu = VMBUS_PCPU_GET(prichan->ch_vmbus, vcpuid, cpu);
1325
1326#define CHAN_VCPU_DIST(ch, vcpu)		\
1327	(((ch)->ch_vcpuid > (vcpu)) ?		\
1328	 ((ch)->ch_vcpuid - (vcpu)) : ((vcpu) - (ch)->ch_vcpuid))
1329
1330#define CHAN_SELECT(ch)				\
1331do {						\
1332	sel = ch;				\
1333	sel_dist = CHAN_VCPU_DIST(ch, vcpu);	\
1334} while (0)
1335
1336	CHAN_SELECT(prichan);
1337
1338	mtx_lock(&prichan->ch_subchan_lock);
1339	TAILQ_FOREACH(chan, &prichan->ch_subchans, ch_sublink) {
1340		uint32_t dist;
1341
1342		KASSERT(chan->ch_stflags & VMBUS_CHAN_ST_OPENED,
1343		    ("chan%u is not opened", chan->ch_id));
1344
1345		if (chan->ch_vcpuid == vcpu) {
1346			/* Exact match; done */
1347			CHAN_SELECT(chan);
1348			break;
1349		}
1350
1351		dist = CHAN_VCPU_DIST(chan, vcpu);
1352		if (sel_dist <= dist) {
1353			/* Far or same distance; skip */
1354			continue;
1355		}
1356
1357		/* Select the closer channel. */
1358		CHAN_SELECT(chan);
1359	}
1360	mtx_unlock(&prichan->ch_subchan_lock);
1361
1362#undef CHAN_SELECT
1363#undef CHAN_VCPU_DIST
1364
1365	return sel;
1366}
1367
1368struct vmbus_channel **
1369vmbus_subchan_get(struct vmbus_channel *pri_chan, int subchan_cnt)
1370{
1371	struct vmbus_channel **ret, *chan;
1372	int i;
1373
1374	KASSERT(subchan_cnt > 0, ("invalid sub-channel count %d", subchan_cnt));
1375
1376	ret = malloc(subchan_cnt * sizeof(struct vmbus_channel *), M_TEMP,
1377	    M_WAITOK);
1378
1379	mtx_lock(&pri_chan->ch_subchan_lock);
1380
1381	while (pri_chan->ch_subchan_cnt < subchan_cnt)
1382		mtx_sleep(pri_chan, &pri_chan->ch_subchan_lock, 0, "subch", 0);
1383
1384	i = 0;
1385	TAILQ_FOREACH(chan, &pri_chan->ch_subchans, ch_sublink) {
1386		/* TODO: refcnt chan */
1387		ret[i] = chan;
1388
1389		++i;
1390		if (i == subchan_cnt)
1391			break;
1392	}
1393	KASSERT(i == subchan_cnt, ("invalid subchan count %d, should be %d",
1394	    pri_chan->ch_subchan_cnt, subchan_cnt));
1395
1396	mtx_unlock(&pri_chan->ch_subchan_lock);
1397
1398	return ret;
1399}
1400
1401void
1402vmbus_subchan_rel(struct vmbus_channel **subchan, int subchan_cnt __unused)
1403{
1404
1405	free(subchan, M_TEMP);
1406}
1407
1408void
1409vmbus_subchan_drain(struct vmbus_channel *pri_chan)
1410{
1411	mtx_lock(&pri_chan->ch_subchan_lock);
1412	while (pri_chan->ch_subchan_cnt > 0)
1413		mtx_sleep(pri_chan, &pri_chan->ch_subchan_lock, 0, "dsubch", 0);
1414	mtx_unlock(&pri_chan->ch_subchan_lock);
1415}
1416
1417void
1418vmbus_chan_msgproc(struct vmbus_softc *sc, const struct vmbus_message *msg)
1419{
1420	vmbus_chanmsg_proc_t msg_proc;
1421	uint32_t msg_type;
1422
1423	msg_type = ((const struct vmbus_chanmsg_hdr *)msg->msg_data)->chm_type;
1424	KASSERT(msg_type < VMBUS_CHANMSG_TYPE_MAX,
1425	    ("invalid message type %u", msg_type));
1426
1427	msg_proc = vmbus_chan_msgprocs[msg_type];
1428	if (msg_proc != NULL)
1429		msg_proc(sc, msg);
1430}
1431
1432void
1433vmbus_chan_set_readbatch(struct vmbus_channel *chan, bool on)
1434{
1435	if (!on)
1436		chan->ch_flags &= ~VMBUS_CHAN_FLAG_BATCHREAD;
1437	else
1438		chan->ch_flags |= VMBUS_CHAN_FLAG_BATCHREAD;
1439}
1440
1441uint32_t
1442vmbus_chan_id(const struct vmbus_channel *chan)
1443{
1444	return chan->ch_id;
1445}
1446
1447uint32_t
1448vmbus_chan_subidx(const struct vmbus_channel *chan)
1449{
1450	return chan->ch_subidx;
1451}
1452
1453bool
1454vmbus_chan_is_primary(const struct vmbus_channel *chan)
1455{
1456	if (VMBUS_CHAN_ISPRIMARY(chan))
1457		return true;
1458	else
1459		return false;
1460}
1461
1462const struct hyperv_guid *
1463vmbus_chan_guid_inst(const struct vmbus_channel *chan)
1464{
1465	return &chan->ch_guid_inst;
1466}
1467
1468int
1469vmbus_chan_prplist_nelem(int br_size, int prpcnt_max, int dlen_max)
1470{
1471	int elem_size;
1472
1473	elem_size = __offsetof(struct vmbus_chanpkt_prplist,
1474	    cp_range[0].gpa_page[prpcnt_max]);
1475	elem_size += dlen_max;
1476	elem_size = VMBUS_CHANPKT_TOTLEN(elem_size);
1477
1478	return (vmbus_br_nelem(br_size, elem_size));
1479}
1480