LXR linux/sound/xen/xen_snd_front

   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#ifndef __XEN_SND_FRONT_EVTCHNL_H
  12#define __XEN_SND_FRONT_EVTCHNL_H
  13
  14#include <xen/interface/io/sndif.h>
  15
  16struct xen_snd_front_info;
  17
  18#ifndef GRANT_INVALID_REF
  19/*
  20 * FIXME: usage of grant reference 0 as invalid grant reference:
  21 * grant reference 0 is valid, but never exposed to a PV driver,
  22 * because of the fact it is already in use/reserved by the PV console.
  23 */
  24#define GRANT_INVALID_REF       0
  25#endif
  26
  27/* Timeout in ms to wait for backend to respond. */
  28#define VSND_WAIT_BACK_MS       3000
  29
  30enum xen_snd_front_evtchnl_state {
  31        EVTCHNL_STATE_DISCONNECTED,
  32        EVTCHNL_STATE_CONNECTED,
  33};
  34
  35enum xen_snd_front_evtchnl_type {
  36        EVTCHNL_TYPE_REQ,
  37        EVTCHNL_TYPE_EVT,
  38};
  39
  40struct xen_snd_front_evtchnl {
  41        struct xen_snd_front_info *front_info;
  42        int gref;
  43        int port;
  44        int irq;
  45        int index;
  46        /* State of the event channel. */
  47        enum xen_snd_front_evtchnl_state state;
  48        enum xen_snd_front_evtchnl_type type;
  49        /* Either response id or incoming event id. */
  50        u16 evt_id;
  51        /* Next request id or next expected event id. */
  52        u16 evt_next_id;
  53        /* Shared ring access lock. */
  54        struct mutex ring_io_lock;
  55        union {
  56                struct {
  57                        struct xen_sndif_front_ring ring;
  58                        struct completion completion;
  59                        /* Serializer for backend IO: request/response. */
  60                        struct mutex req_io_lock;
  61
  62                        /* Latest response status. */
  63                        int resp_status;
  64                        union {
  65                                struct xensnd_query_hw_param hw_param;
  66                        } resp;
  67                } req;
  68                struct {
  69                        struct xensnd_event_page *page;
  70                        /* This is needed to handle XENSND_EVT_CUR_POS event. */
  71                        struct snd_pcm_substream *substream;
  72                } evt;
  73        } u;
  74};
  75
  76struct xen_snd_front_evtchnl_pair {
  77        struct xen_snd_front_evtchnl req;
  78        struct xen_snd_front_evtchnl evt;
  79};
  80
  81int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
  82                                     int num_streams);
  83
  84void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info);
  85
  86int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info);
  87
  88void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl);
  89
  90void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
  91                                              bool is_connected);
  92
  93void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair);
  94
  95#endif /* __XEN_SND_FRONT_EVTCHNL_H */
  96