[mirror_ubuntu-hirsute-kernel.git] / sound / xen / xen_snd_front_evtchnl.c

// SPDX-License-Identifier: GPL-2.0 OR MIT

/*
 * Xen para-virtual sound device
 *
 * Copyright (C) 2016-2018 EPAM Systems Inc.
 *
 * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
 */

#include <xen/events.h>
#include <xen/grant_table.h>
#include <xen/xen.h>
#include <xen/xenbus.h>

#include "xen_snd_front.h"
#include "xen_snd_front_alsa.h"
#include "xen_snd_front_cfg.h"
#include "xen_snd_front_evtchnl.h"

static irqreturn_t evtchnl_interrupt_req(int irq, void *dev_id)
{
	struct xen_snd_front_evtchnl *channel = dev_id;
	struct xen_snd_front_info *front_info = channel->front_info;
	struct xensnd_resp *resp;
	RING_IDX i, rp;

	if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
		return IRQ_HANDLED;

	mutex_lock(&channel->ring_io_lock);

again:
	rp = channel->u.req.ring.sring->rsp_prod;
	/* Ensure we see queued responses up to rp. */
	rmb();

	/*
	 * Assume that the backend is trusted to always write sane values
	 * to the ring counters, so no overflow checks on frontend side
	 * are required.
	 */
	for (i = channel->u.req.ring.rsp_cons; i != rp; i++) {
		resp = RING_GET_RESPONSE(&channel->u.req.ring, i);
		if (resp->id != channel->evt_id)
			continue;
		switch (resp->operation) {
		case XENSND_OP_OPEN:
			/* fall through */
		case XENSND_OP_CLOSE:
			/* fall through */
		case XENSND_OP_READ:
			/* fall through */
		case XENSND_OP_WRITE:
			/* fall through */
		case XENSND_OP_TRIGGER:
			channel->u.req.resp_status = resp->status;
			complete(&channel->u.req.completion);
			break;
		case XENSND_OP_HW_PARAM_QUERY:
			channel->u.req.resp_status = resp->status;
			channel->u.req.resp.hw_param =
					resp->resp.hw_param;
			complete(&channel->u.req.completion);
			break;

		default:
			dev_err(&front_info->xb_dev->dev,
				"Operation %d is not supported\n",
				resp->operation);
			break;
		}
	}

	channel->u.req.ring.rsp_cons = i;
	if (i != channel->u.req.ring.req_prod_pvt) {
		int more_to_do;

		RING_FINAL_CHECK_FOR_RESPONSES(&channel->u.req.ring,
					       more_to_do);
		if (more_to_do)
			goto again;
	} else {
		channel->u.req.ring.sring->rsp_event = i + 1;
	}

	mutex_unlock(&channel->ring_io_lock);
	return IRQ_HANDLED;
}

static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)
{
	struct xen_snd_front_evtchnl *channel = dev_id;
	struct xensnd_event_page *page = channel->u.evt.page;
	u32 cons, prod;

	if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
		return IRQ_HANDLED;

	mutex_lock(&channel->ring_io_lock);

	prod = page->in_prod;
	/* Ensure we see ring contents up to prod. */
	virt_rmb();
	if (prod == page->in_cons)
		goto out;

	/*
	 * Assume that the backend is trusted to always write sane values
	 * to the ring counters, so no overflow checks on frontend side
	 * are required.
	 */
	for (cons = page->in_cons; cons != prod; cons++) {
		struct xensnd_evt *event;

		event = &XENSND_IN_RING_REF(page, cons);
		if (unlikely(event->id != channel->evt_id++))
			continue;

		switch (event->type) {
		case XENSND_EVT_CUR_POS:
			xen_snd_front_alsa_handle_cur_pos(channel,
							  event->op.cur_pos.position);
			break;
		}
	}

	page->in_cons = cons;
	/* Ensure ring contents. */
	virt_wmb();

out:
	mutex_unlock(&channel->ring_io_lock);
	return IRQ_HANDLED;
}

void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel)
{
	int notify;

	channel->u.req.ring.req_prod_pvt++;
	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&channel->u.req.ring, notify);
	if (notify)
		notify_remote_via_irq(channel->irq);
}

static void evtchnl_free(struct xen_snd_front_info *front_info,
			 struct xen_snd_front_evtchnl *channel)
{
	unsigned long page = 0;

	if (channel->type == EVTCHNL_TYPE_REQ)
		page = (unsigned long)channel->u.req.ring.sring;
	else if (channel->type == EVTCHNL_TYPE_EVT)
		page = (unsigned long)channel->u.evt.page;

	if (!page)
		return;

	channel->state = EVTCHNL_STATE_DISCONNECTED;
	if (channel->type == EVTCHNL_TYPE_REQ) {
		/* Release all who still waits for response if any. */
		channel->u.req.resp_status = -EIO;
		complete_all(&channel->u.req.completion);
	}

	if (channel->irq)
		unbind_from_irqhandler(channel->irq, channel);

	if (channel->port)
		xenbus_free_evtchn(front_info->xb_dev, channel->port);

	/* End access and free the page. */
	if (channel->gref != GRANT_INVALID_REF)
		gnttab_end_foreign_access(channel->gref, 0, page);
	else
		free_page(page);

	memset(channel, 0, sizeof(*channel));
}

void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info)
{
	int i;

	if (!front_info->evt_pairs)
		return;

	for (i = 0; i < front_info->num_evt_pairs; i++) {
		evtchnl_free(front_info, &front_info->evt_pairs[i].req);
		evtchnl_free(front_info, &front_info->evt_pairs[i].evt);
	}

	kfree(front_info->evt_pairs);
	front_info->evt_pairs = NULL;
}

static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index,
			 struct xen_snd_front_evtchnl *channel,
			 enum xen_snd_front_evtchnl_type type)
{
	struct xenbus_device *xb_dev = front_info->xb_dev;
	unsigned long page;
	grant_ref_t gref;
	irq_handler_t handler;
	char *handler_name = NULL;
	int ret;

	memset(channel, 0, sizeof(*channel));
	channel->type = type;
	channel->index = index;
	channel->front_info = front_info;
	channel->state = EVTCHNL_STATE_DISCONNECTED;
	channel->gref = GRANT_INVALID_REF;
	page = get_zeroed_page(GFP_KERNEL);
	if (!page) {
		ret = -ENOMEM;
		goto fail;
	}

	handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME,
				 type == EVTCHNL_TYPE_REQ ?
				 XENSND_FIELD_RING_REF :
				 XENSND_FIELD_EVT_RING_REF);
	if (!handler_name) {
		ret = -ENOMEM;
		goto fail;
	}

	mutex_init(&channel->ring_io_lock);

	if (type == EVTCHNL_TYPE_REQ) {
		struct xen_sndif_sring *sring = (struct xen_sndif_sring *)page;

		init_completion(&channel->u.req.completion);
		mutex_init(&channel->u.req.req_io_lock);
		SHARED_RING_INIT(sring);
		FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE);

		ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
		if (ret < 0) {
			channel->u.req.ring.sring = NULL;
			goto fail;
		}

		handler = evtchnl_interrupt_req;
	} else {
		ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
						  virt_to_gfn((void *)page), 0);
		if (ret < 0)
			goto fail;

		channel->u.evt.page = (struct xensnd_event_page *)page;
		gref = ret;
		handler = evtchnl_interrupt_evt;
	}

	channel->gref = gref;

	ret = xenbus_alloc_evtchn(xb_dev, &channel->port);
	if (ret < 0)
		goto fail;

	ret = bind_evtchn_to_irq(channel->port);
	if (ret < 0) {
		dev_err(&xb_dev->dev,
			"Failed to bind IRQ for domid %d port %d: %d\n",
			front_info->xb_dev->otherend_id, channel->port, ret);
		goto fail;
	}

	channel->irq = ret;

	ret = request_threaded_irq(channel->irq, NULL, handler,
				   IRQF_ONESHOT, handler_name, channel);
	if (ret < 0) {
		dev_err(&xb_dev->dev, "Failed to request IRQ %d: %d\n",
			channel->irq, ret);
		goto fail;
	}

	kfree(handler_name);
	return 0;

fail:
	if (page)
		free_page(page);
	kfree(handler_name);
	dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret);
	return ret;
}

int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
				     int num_streams)
{
	struct xen_front_cfg_card *cfg = &front_info->cfg;
	struct device *dev = &front_info->xb_dev->dev;
	int d, ret = 0;

	front_info->evt_pairs =
			kcalloc(num_streams,
				sizeof(struct xen_snd_front_evtchnl_pair),
				GFP_KERNEL);
	if (!front_info->evt_pairs)
		return -ENOMEM;

	/* Iterate over devices and their streams and create event channels. */
	for (d = 0; d < cfg->num_pcm_instances; d++) {
		struct xen_front_cfg_pcm_instance *pcm_instance;
		int s, index;

		pcm_instance = &cfg->pcm_instances[d];

		for (s = 0; s < pcm_instance->num_streams_pb; s++) {
			index = pcm_instance->streams_pb[s].index;

			ret = evtchnl_alloc(front_info, index,
					    &front_info->evt_pairs[index].req,
					    EVTCHNL_TYPE_REQ);
			if (ret < 0) {
				dev_err(dev, "Error allocating control channel\n");
				goto fail;
			}

			ret = evtchnl_alloc(front_info, index,
					    &front_info->evt_pairs[index].evt,
					    EVTCHNL_TYPE_EVT);
			if (ret < 0) {
				dev_err(dev, "Error allocating in-event channel\n");
				goto fail;
			}
		}

		for (s = 0; s < pcm_instance->num_streams_cap; s++) {
			index = pcm_instance->streams_cap[s].index;

			ret = evtchnl_alloc(front_info, index,
					    &front_info->evt_pairs[index].req,
					    EVTCHNL_TYPE_REQ);
			if (ret < 0) {
				dev_err(dev, "Error allocating control channel\n");
				goto fail;
			}

			ret = evtchnl_alloc(front_info, index,
					    &front_info->evt_pairs[index].evt,
					    EVTCHNL_TYPE_EVT);
			if (ret < 0) {
				dev_err(dev, "Error allocating in-event channel\n");
				goto fail;
			}
		}
	}

	front_info->num_evt_pairs = num_streams;
	return 0;

fail:
	xen_snd_front_evtchnl_free_all(front_info);
	return ret;
}

static int evtchnl_publish(struct xenbus_transaction xbt,
			   struct xen_snd_front_evtchnl *channel,
			   const char *path, const char *node_ring,
			   const char *node_chnl)
{
	struct xenbus_device *xb_dev = channel->front_info->xb_dev;
	int ret;

	/* Write control channel ring reference. */
	ret = xenbus_printf(xbt, path, node_ring, "%u", channel->gref);
	if (ret < 0) {
		dev_err(&xb_dev->dev, "Error writing ring-ref: %d\n", ret);
		return ret;
	}

	/* Write event channel ring reference. */
	ret = xenbus_printf(xbt, path, node_chnl, "%u", channel->port);
	if (ret < 0) {
		dev_err(&xb_dev->dev, "Error writing event channel: %d\n", ret);
		return ret;
	}

	return 0;
}

int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info)
{
	struct xen_front_cfg_card *cfg = &front_info->cfg;
	struct xenbus_transaction xbt;
	int ret, d;

again:
	ret = xenbus_transaction_start(&xbt);
	if (ret < 0) {
		xenbus_dev_fatal(front_info->xb_dev, ret,
				 "starting transaction");
		return ret;
	}

	for (d = 0; d < cfg->num_pcm_instances; d++) {
		struct xen_front_cfg_pcm_instance *pcm_instance;
		int s, index;

		pcm_instance = &cfg->pcm_instances[d];

		for (s = 0; s < pcm_instance->num_streams_pb; s++) {
			index = pcm_instance->streams_pb[s].index;

			ret = evtchnl_publish(xbt,
					      &front_info->evt_pairs[index].req,
					      pcm_instance->streams_pb[s].xenstore_path,
					      XENSND_FIELD_RING_REF,
					      XENSND_FIELD_EVT_CHNL);
			if (ret < 0)
				goto fail;

			ret = evtchnl_publish(xbt,
					      &front_info->evt_pairs[index].evt,
					      pcm_instance->streams_pb[s].xenstore_path,
					      XENSND_FIELD_EVT_RING_REF,
					      XENSND_FIELD_EVT_EVT_CHNL);
			if (ret < 0)
				goto fail;
		}

		for (s = 0; s < pcm_instance->num_streams_cap; s++) {
			index = pcm_instance->streams_cap[s].index;

			ret = evtchnl_publish(xbt,
					      &front_info->evt_pairs[index].req,
					      pcm_instance->streams_cap[s].xenstore_path,
					      XENSND_FIELD_RING_REF,
					      XENSND_FIELD_EVT_CHNL);
			if (ret < 0)
				goto fail;

			ret = evtchnl_publish(xbt,
					      &front_info->evt_pairs[index].evt,
					      pcm_instance->streams_cap[s].xenstore_path,
					      XENSND_FIELD_EVT_RING_REF,
					      XENSND_FIELD_EVT_EVT_CHNL);
			if (ret < 0)
				goto fail;
		}
	}
	ret = xenbus_transaction_end(xbt, 0);
	if (ret < 0) {
		if (ret == -EAGAIN)
			goto again;

		xenbus_dev_fatal(front_info->xb_dev, ret,
				 "completing transaction");
		goto fail_to_end;
	}
	return 0;
fail:
	xenbus_transaction_end(xbt, 1);
fail_to_end:
	xenbus_dev_fatal(front_info->xb_dev, ret, "writing XenStore");
	return ret;
}

void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
					      bool is_connected)
{
	enum xen_snd_front_evtchnl_state state;

	if (is_connected)
		state = EVTCHNL_STATE_CONNECTED;
	else
		state = EVTCHNL_STATE_DISCONNECTED;

	mutex_lock(&evt_pair->req.ring_io_lock);
	evt_pair->req.state = state;
	mutex_unlock(&evt_pair->req.ring_io_lock);

	mutex_lock(&evt_pair->evt.ring_io_lock);
	evt_pair->evt.state = state;
	mutex_unlock(&evt_pair->evt.ring_io_lock);
}

void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair)
{
	mutex_lock(&evt_pair->req.ring_io_lock);
	evt_pair->req.evt_next_id = 0;
	mutex_unlock(&evt_pair->req.ring_io_lock);

	mutex_lock(&evt_pair->evt.ring_io_lock);
	evt_pair->evt.evt_next_id = 0;
	mutex_unlock(&evt_pair->evt.ring_io_lock);
}
Commit	Line	Data
788ef64a OA	1	// SPDX-License-Identifier: GPL-2.0 OR MIT
	2
	3	/*
	4	* Xen para-virtual sound device
	5	*
	6	* Copyright (C) 2016-2018 EPAM Systems Inc.
	7	*
	8	* Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
	9	*/
	10
	11	#include <xen/events.h>
	12	#include <xen/grant_table.h>
	13	#include <xen/xen.h>
	14	#include <xen/xenbus.h>
	15
	16	#include "xen_snd_front.h"
1cee5593	17	#include "xen_snd_front_alsa.h"
788ef64a OA	18	#include "xen_snd_front_cfg.h"
	19	#include "xen_snd_front_evtchnl.h"
	20
	21	static irqreturn_t evtchnl_interrupt_req(int irq, void *dev_id)
	22	{
	23	struct xen_snd_front_evtchnl *channel = dev_id;
	24	struct xen_snd_front_info *front_info = channel->front_info;
	25	struct xensnd_resp *resp;
	26	RING_IDX i, rp;
	27
	28	if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
	29	return IRQ_HANDLED;
	30
	31	mutex_lock(&channel->ring_io_lock);
	32
	33	again:
	34	rp = channel->u.req.ring.sring->rsp_prod;
	35	/* Ensure we see queued responses up to rp. */
	36	rmb();
	37
	38	/*
	39	* Assume that the backend is trusted to always write sane values
	40	* to the ring counters, so no overflow checks on frontend side
	41	* are required.
	42	*/
	43	for (i = channel->u.req.ring.rsp_cons; i != rp; i++) {
	44	resp = RING_GET_RESPONSE(&channel->u.req.ring, i);
	45	if (resp->id != channel->evt_id)
	46	continue;
	47	switch (resp->operation) {
	48	case XENSND_OP_OPEN:
	49	/* fall through */
	50	case XENSND_OP_CLOSE:
	51	/* fall through */
	52	case XENSND_OP_READ:
	53	/* fall through */
	54	case XENSND_OP_WRITE:
	55	/* fall through */
	56	case XENSND_OP_TRIGGER:
	57	channel->u.req.resp_status = resp->status;
	58	complete(&channel->u.req.completion);
	59	break;
	60	case XENSND_OP_HW_PARAM_QUERY:
	61	channel->u.req.resp_status = resp->status;
	62	channel->u.req.resp.hw_param =
	63	resp->resp.hw_param;
	64	complete(&channel->u.req.completion);
	65	break;
	66
	67	default:
	68	dev_err(&front_info->xb_dev->dev,
	69	"Operation %d is not supported\n",
	70	resp->operation);
	71	break;
	72	}
	73	}
	74
	75	channel->u.req.ring.rsp_cons = i;
	76	if (i != channel->u.req.ring.req_prod_pvt) {
	77	int more_to_do;
	78
	79	RING_FINAL_CHECK_FOR_RESPONSES(&channel->u.req.ring,
	80	more_to_do);
	81	if (more_to_do)
82	goto again;
83	} else {
84	channel->u.req.ring.sring->rsp_event = i + 1;
85	}
86
87	mutex_unlock(&channel->ring_io_lock);
88	return IRQ_HANDLED;
89	}
90
91	static irqreturn_t evtchnl_interrupt_evt(int irq, void *dev_id)
92	{
93	struct xen_snd_front_evtchnl *channel = dev_id;
94	struct xensnd_event_page *page = channel->u.evt.page;
95	u32 cons, prod;
96
97	if (unlikely(channel->state != EVTCHNL_STATE_CONNECTED))
98	return IRQ_HANDLED;
99
100	mutex_lock(&channel->ring_io_lock);
101
102	prod = page->in_prod;
103	/* Ensure we see ring contents up to prod. */
104	virt_rmb();
105	if (prod == page->in_cons)
106	goto out;
107
108	/*
109	* Assume that the backend is trusted to always write sane values
110	* to the ring counters, so no overflow checks on frontend side
111	* are required.
112	*/
113	for (cons = page->in_cons; cons != prod; cons++) {
114	struct xensnd_evt *event;
115
116	event = &XENSND_IN_RING_REF(page, cons);
117	if (unlikely(event->id != channel->evt_id++))
118	continue;
119
120	switch (event->type) {
121	case XENSND_EVT_CUR_POS:
1cee5593 OA	122	xen_snd_front_alsa_handle_cur_pos(channel,
1cee5593 OA	123	event->op.cur_pos.position);
788ef64a OA	124	break;
	125	}
	126	}
	127
	128	page->in_cons = cons;
	129	/* Ensure ring contents. */
	130	virt_wmb();
	131
	132	out:
	133	mutex_unlock(&channel->ring_io_lock);
	134	return IRQ_HANDLED;
	135	}
	136
	137	void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *channel)
	138	{
	139	int notify;
	140
	141	channel->u.req.ring.req_prod_pvt++;
	142	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&channel->u.req.ring, notify);
	143	if (notify)
	144	notify_remote_via_irq(channel->irq);
	145	}
	146
	147	static void evtchnl_free(struct xen_snd_front_info *front_info,
	148	struct xen_snd_front_evtchnl *channel)
	149	{
	150	unsigned long page = 0;
	151
	152	if (channel->type == EVTCHNL_TYPE_REQ)
	153	page = (unsigned long)channel->u.req.ring.sring;
	154	else if (channel->type == EVTCHNL_TYPE_EVT)
	155	page = (unsigned long)channel->u.evt.page;
	156
	157	if (!page)
	158	return;
	159
	160	channel->state = EVTCHNL_STATE_DISCONNECTED;
	161	if (channel->type == EVTCHNL_TYPE_REQ) {
	162	/* Release all who still waits for response if any. */
	163	channel->u.req.resp_status = -EIO;
	164	complete_all(&channel->u.req.completion);
	165	}
	166
	167	if (channel->irq)
	168	unbind_from_irqhandler(channel->irq, channel);
	169
	170	if (channel->port)
	171	xenbus_free_evtchn(front_info->xb_dev, channel->port);
	172
	173	/* End access and free the page. */
	174	if (channel->gref != GRANT_INVALID_REF)
	175	gnttab_end_foreign_access(channel->gref, 0, page);
	176	else
	177	free_page(page);
	178
	179	memset(channel, 0, sizeof(*channel));
	180	}
	181
	182	void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info)
	183	{
	184	int i;
	185
	186	if (!front_info->evt_pairs)
	187	return;
188
189	for (i = 0; i < front_info->num_evt_pairs; i++) {
190	evtchnl_free(front_info, &front_info->evt_pairs[i].req);
191	evtchnl_free(front_info, &front_info->evt_pairs[i].evt);
192	}
193
194	kfree(front_info->evt_pairs);
195	front_info->evt_pairs = NULL;
196	}
197
198	static int evtchnl_alloc(struct xen_snd_front_info *front_info, int index,
199	struct xen_snd_front_evtchnl *channel,
200	enum xen_snd_front_evtchnl_type type)
201	{
202	struct xenbus_device *xb_dev = front_info->xb_dev;
203	unsigned long page;
204	grant_ref_t gref;
205	irq_handler_t handler;
206	char *handler_name = NULL;
207	int ret;
208
209	memset(channel, 0, sizeof(*channel));
210	channel->type = type;
211	channel->index = index;
212	channel->front_info = front_info;
213	channel->state = EVTCHNL_STATE_DISCONNECTED;
214	channel->gref = GRANT_INVALID_REF;
215	page = get_zeroed_page(GFP_KERNEL);
216	if (!page) {
217	ret = -ENOMEM;
218	goto fail;
219	}
220
221	handler_name = kasprintf(GFP_KERNEL, "%s-%s", XENSND_DRIVER_NAME,
222	type == EVTCHNL_TYPE_REQ ?
223	XENSND_FIELD_RING_REF :
224	XENSND_FIELD_EVT_RING_REF);
225	if (!handler_name) {
226	ret = -ENOMEM;
227	goto fail;
228	}
229
230	mutex_init(&channel->ring_io_lock);
231
232	if (type == EVTCHNL_TYPE_REQ) {
233	struct xen_sndif_sring sring = (struct xen_sndif_sring )page;
234
235	init_completion(&channel->u.req.completion);
236	mutex_init(&channel->u.req.req_io_lock);
237	SHARED_RING_INIT(sring);
238	FRONT_RING_INIT(&channel->u.req.ring, sring, XEN_PAGE_SIZE);
239
240	ret = xenbus_grant_ring(xb_dev, sring, 1, &gref);
241	if (ret < 0) {
242	channel->u.req.ring.sring = NULL;
243	goto fail;
244	}
245
246	handler = evtchnl_interrupt_req;
247	} else {
248	ret = gnttab_grant_foreign_access(xb_dev->otherend_id,
249	virt_to_gfn((void *)page), 0);
250	if (ret < 0)
251	goto fail;
252
253	channel->u.evt.page = (struct xensnd_event_page *)page;
254	gref = ret;
255	handler = evtchnl_interrupt_evt;
256	}
257
258	channel->gref = gref;
259
260	ret = xenbus_alloc_evtchn(xb_dev, &channel->port);
261	if (ret < 0)
262	goto fail;
263
264	ret = bind_evtchn_to_irq(channel->port);
265	if (ret < 0) {
266	dev_err(&xb_dev->dev,
267	"Failed to bind IRQ for domid %d port %d: %d\n",
268	front_info->xb_dev->otherend_id, channel->port, ret);
269	goto fail;
270	}
271
272	channel->irq = ret;
273
274	ret = request_threaded_irq(channel->irq, NULL, handler,
275	IRQF_ONESHOT, handler_name, channel);
276	if (ret < 0) {
277	dev_err(&xb_dev->dev, "Failed to request IRQ %d: %d\n",
278	channel->irq, ret);
279	goto fail;
280	}
281
282	kfree(handler_name);
283	return 0;
284
285	fail:
286	if (page)
287	free_page(page);
288	kfree(handler_name);
289	dev_err(&xb_dev->dev, "Failed to allocate ring: %d\n", ret);
290	return ret;
291	}
292
293	int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
294	int num_streams)
295	{
296	struct xen_front_cfg_card *cfg = &front_info->cfg;
297	struct device *dev = &front_info->xb_dev->dev;
298	int d, ret = 0;
299
300	front_info->evt_pairs =
301	kcalloc(num_streams,
302	sizeof(struct xen_snd_front_evtchnl_pair),
303	GFP_KERNEL);
304	if (!front_info->evt_pairs)
305	return -ENOMEM;
306
307	/* Iterate over devices and their streams and create event channels. */
308	for (d = 0; d < cfg->num_pcm_instances; d++) {
309	struct xen_front_cfg_pcm_instance *pcm_instance;
310	int s, index;
311
312	pcm_instance = &cfg->pcm_instances[d];
313
314	for (s = 0; s < pcm_instance->num_streams_pb; s++) {
315	index = pcm_instance->streams_pb[s].index;
316
317	ret = evtchnl_alloc(front_info, index,
318	&front_info->evt_pairs[index].req,
319	EVTCHNL_TYPE_REQ);
320	if (ret < 0) {
321	dev_err(dev, "Error allocating control channel\n");
322	goto fail;
323	}
324
325	ret = evtchnl_alloc(front_info, index,
326	&front_info->evt_pairs[index].evt,
327	EVTCHNL_TYPE_EVT);
328	if (ret < 0) {
329	dev_err(dev, "Error allocating in-event channel\n");
330	goto fail;
331	}
332	}
333
334	for (s = 0; s < pcm_instance->num_streams_cap; s++) {
335	index = pcm_instance->streams_cap[s].index;
336
337	ret = evtchnl_alloc(front_info, index,
338	&front_info->evt_pairs[index].req,
339	EVTCHNL_TYPE_REQ);
340	if (ret < 0) {
341	dev_err(dev, "Error allocating control channel\n");
342	goto fail;
343	}
344
345	ret = evtchnl_alloc(front_info, index,
346	&front_info->evt_pairs[index].evt,
347	EVTCHNL_TYPE_EVT);
348	if (ret < 0) {
349	dev_err(dev, "Error allocating in-event channel\n");
350	goto fail;
351	}
352	}
353	}
788ef64a OA	354
	355	front_info->num_evt_pairs = num_streams;
	356	return 0;
	357
	358	fail:
	359	xen_snd_front_evtchnl_free_all(front_info);
	360	return ret;
	361	}
	362
	363	static int evtchnl_publish(struct xenbus_transaction xbt,
	364	struct xen_snd_front_evtchnl *channel,
	365	const char path, const char node_ring,
	366	const char *node_chnl)
	367	{
	368	struct xenbus_device *xb_dev = channel->front_info->xb_dev;
	369	int ret;
	370
	371	/* Write control channel ring reference. */
	372	ret = xenbus_printf(xbt, path, node_ring, "%u", channel->gref);
	373	if (ret < 0) {
	374	dev_err(&xb_dev->dev, "Error writing ring-ref: %d\n", ret);
	375	return ret;
	376	}
	377
	378	/* Write event channel ring reference. */
	379	ret = xenbus_printf(xbt, path, node_chnl, "%u", channel->port);
	380	if (ret < 0) {
	381	dev_err(&xb_dev->dev, "Error writing event channel: %d\n", ret);
	382	return ret;
	383	}
	384
	385	return 0;
	386	}
	387
	388	int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info)
	389	{
	390	struct xen_front_cfg_card *cfg = &front_info->cfg;
	391	struct xenbus_transaction xbt;
	392	int ret, d;
	393
	394	again:
	395	ret = xenbus_transaction_start(&xbt);
	396	if (ret < 0) {
	397	xenbus_dev_fatal(front_info->xb_dev, ret,
	398	"starting transaction");
	399	return ret;
	400	}
	401
	402	for (d = 0; d < cfg->num_pcm_instances; d++) {
	403	struct xen_front_cfg_pcm_instance *pcm_instance;
	404	int s, index;
	405
	406	pcm_instance = &cfg->pcm_instances[d];
	407
	408	for (s = 0; s < pcm_instance->num_streams_pb; s++) {
	409	index = pcm_instance->streams_pb[s].index;
	410
	411	ret = evtchnl_publish(xbt,
	412	&front_info->evt_pairs[index].req,
	413	pcm_instance->streams_pb[s].xenstore_path,
	414	XENSND_FIELD_RING_REF,
	415	XENSND_FIELD_EVT_CHNL);
	416	if (ret < 0)
	417	goto fail;
418
419	ret = evtchnl_publish(xbt,
420	&front_info->evt_pairs[index].evt,
421	pcm_instance->streams_pb[s].xenstore_path,
422	XENSND_FIELD_EVT_RING_REF,
423	XENSND_FIELD_EVT_EVT_CHNL);
424	if (ret < 0)
425	goto fail;
426	}
427
428	for (s = 0; s < pcm_instance->num_streams_cap; s++) {
429	index = pcm_instance->streams_cap[s].index;
430
431	ret = evtchnl_publish(xbt,
432	&front_info->evt_pairs[index].req,
433	pcm_instance->streams_cap[s].xenstore_path,
434	XENSND_FIELD_RING_REF,
435	XENSND_FIELD_EVT_CHNL);
436	if (ret < 0)
437	goto fail;
438
439	ret = evtchnl_publish(xbt,
440	&front_info->evt_pairs[index].evt,
441	pcm_instance->streams_cap[s].xenstore_path,
442	XENSND_FIELD_EVT_RING_REF,
443	XENSND_FIELD_EVT_EVT_CHNL);
444	if (ret < 0)
445	goto fail;
446	}
447	}
448	ret = xenbus_transaction_end(xbt, 0);
449	if (ret < 0) {
450	if (ret == -EAGAIN)
451	goto again;
452
453	xenbus_dev_fatal(front_info->xb_dev, ret,
454	"completing transaction");
455	goto fail_to_end;
456	}
457	return 0;
458	fail:
459	xenbus_transaction_end(xbt, 1);
460	fail_to_end:
461	xenbus_dev_fatal(front_info->xb_dev, ret, "writing XenStore");
462	return ret;
463	}
464
465	void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
466	bool is_connected)
467	{
468	enum xen_snd_front_evtchnl_state state;
469
470	if (is_connected)
471	state = EVTCHNL_STATE_CONNECTED;
472	else
473	state = EVTCHNL_STATE_DISCONNECTED;
474
475	mutex_lock(&evt_pair->req.ring_io_lock);
476	evt_pair->req.state = state;
477	mutex_unlock(&evt_pair->req.ring_io_lock);
478
479	mutex_lock(&evt_pair->evt.ring_io_lock);
480	evt_pair->evt.state = state;
481	mutex_unlock(&evt_pair->evt.ring_io_lock);
482	}
483
484	void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair)
485	{
486	mutex_lock(&evt_pair->req.ring_io_lock);
487	evt_pair->req.evt_next_id = 0;
488	mutex_unlock(&evt_pair->req.ring_io_lock);
489
490	mutex_lock(&evt_pair->evt.ring_io_lock);
491	evt_pair->evt.evt_next_id = 0;
492	mutex_unlock(&evt_pair->evt.ring_io_lock);
493	}
494