Commit 788ef64a authored by Oleksandr Andrushchenko's avatar Oleksandr Andrushchenko Committed by Takashi Iwai

ALSA: xen-front: Implement Xen event channel handling

Handle Xen event channels:
  - create for all configured streams and publish
    corresponding ring references and event channels in Xen store,
    so backend can connect
  - implement event channels interrupt handlers
  - create and destroy event channels with respect to Xen bus state
Signed-off-by: default avatarOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent fd3b3604
# SPDX-License-Identifier: GPL-2.0 OR MIT
snd_xen_front-objs := xen_snd_front.o \
xen_snd_front_cfg.o
xen_snd_front_cfg.o \
xen_snd_front_evtchnl.o
obj-$(CONFIG_SND_XEN_FRONTEND) += snd_xen_front.o
......@@ -18,9 +18,11 @@
#include <xen/interface/io/sndif.h>
#include "xen_snd_front.h"
#include "xen_snd_front_evtchnl.h"
static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
{
xen_snd_front_evtchnl_free_all(front_info);
}
static int sndback_initwait(struct xen_snd_front_info *front_info)
......@@ -32,7 +34,12 @@ static int sndback_initwait(struct xen_snd_front_info *front_info)
if (ret < 0)
return ret;
return 0;
/* create event channels for all streams and publish */
ret = xen_snd_front_evtchnl_create_all(front_info, num_streams);
if (ret < 0)
return ret;
return xen_snd_front_evtchnl_publish_all(front_info);
}
static int sndback_connect(struct xen_snd_front_info *front_info)
......
......@@ -13,9 +13,14 @@
#include "xen_snd_front_cfg.h"
struct xen_snd_front_evtchnl_pair;
struct xen_snd_front_info {
struct xenbus_device *xb_dev;
int num_evt_pairs;
struct xen_snd_front_evtchnl_pair *evt_pairs;
struct xen_front_cfg_card cfg;
};
......
This diff is collapsed.
/* 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>
*/
#ifndef __XEN_SND_FRONT_EVTCHNL_H
#define __XEN_SND_FRONT_EVTCHNL_H
#include <xen/interface/io/sndif.h>
struct xen_snd_front_info;
#ifndef GRANT_INVALID_REF
/*
* FIXME: usage of grant reference 0 as invalid grant reference:
* grant reference 0 is valid, but never exposed to a PV driver,
* because of the fact it is already in use/reserved by the PV console.
*/
#define GRANT_INVALID_REF 0
#endif
/* Timeout in ms to wait for backend to respond. */
#define VSND_WAIT_BACK_MS 3000
enum xen_snd_front_evtchnl_state {
EVTCHNL_STATE_DISCONNECTED,
EVTCHNL_STATE_CONNECTED,
};
enum xen_snd_front_evtchnl_type {
EVTCHNL_TYPE_REQ,
EVTCHNL_TYPE_EVT,
};
struct xen_snd_front_evtchnl {
struct xen_snd_front_info *front_info;
int gref;
int port;
int irq;
int index;
/* State of the event channel. */
enum xen_snd_front_evtchnl_state state;
enum xen_snd_front_evtchnl_type type;
/* Either response id or incoming event id. */
u16 evt_id;
/* Next request id or next expected event id. */
u16 evt_next_id;
/* Shared ring access lock. */
struct mutex ring_io_lock;
union {
struct {
struct xen_sndif_front_ring ring;
struct completion completion;
/* Serializer for backend IO: request/response. */
struct mutex req_io_lock;
/* Latest response status. */
int resp_status;
union {
struct xensnd_query_hw_param hw_param;
} resp;
} req;
struct {
struct xensnd_event_page *page;
/* This is needed to handle XENSND_EVT_CUR_POS event. */
struct snd_pcm_substream *substream;
} evt;
} u;
};
struct xen_snd_front_evtchnl_pair {
struct xen_snd_front_evtchnl req;
struct xen_snd_front_evtchnl evt;
};
int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
int num_streams);
void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info);
int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info);
void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl);
void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
bool is_connected);
void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair);
#endif /* __XEN_SND_FRONT_EVTCHNL_H */
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