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authorOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>2018-05-14 09:27:39 +0300
committerTakashi Iwai <tiwai@suse.de>2018-05-16 12:58:41 +0200
commit788ef64a2caee38cc4b8890abd3d7e54dfa3bcc9 (patch)
treed30d0a599df3ca130513ee7400ed266b8e4432d1 /sound/xen/xen_snd_front_evtchnl.h
parentfd3b36045c2c612b5f44a47f388677af256d1d0a (diff)
downloadlinux-stericsson-788ef64a2caee38cc4b8890abd3d7e54dfa3bcc9.tar.gz
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: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/xen/xen_snd_front_evtchnl.h')
-rw-r--r--sound/xen/xen_snd_front_evtchnl.h95
1 files changed, 95 insertions, 0 deletions
diff --git a/sound/xen/xen_snd_front_evtchnl.h b/sound/xen/xen_snd_front_evtchnl.h
new file mode 100644
index 000000000000..cbe51fd1ec15
--- /dev/null
+++ b/sound/xen/xen_snd_front_evtchnl.h
@@ -0,0 +1,95 @@
+/* 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 */