* [Xen-devel][PATCH v2 2/3] sndif: Add explicit back and front synchronization
2018-03-14 16:02 [Xen-devel][PATCH v2 0/3] sndif: add explicit back and front synchronization Oleksandr Andrushchenko
2018-03-14 16:02 ` [Xen-devel][PATCH v2 1/3] sndif: Introduce protocol version Oleksandr Andrushchenko
@ 2018-03-14 16:02 ` Oleksandr Andrushchenko
2018-03-15 20:17 ` Konrad Rzeszutek Wilk
2018-03-14 16:02 ` [Xen-devel][PATCH v2 3/3] sndif: Add explicit back and front parameter negotiation Oleksandr Andrushchenko
2 siblings, 1 reply; 7+ messages in thread
From: Oleksandr Andrushchenko @ 2018-03-14 16:02 UTC (permalink / raw)
To: alsa-devel, xen-devel, konrad.wilk, tiwai
Cc: andr2000, Clemens Ladisch, Takashi Sakamoto, Oleksandr Grytsov,
Oleksandr Andrushchenko
From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
In order to provide explicit synchronization between backend and
frontend the following changes are introduced in the protocol:
- bump protocol version to 2
- add new ring buffer for sending asynchronous events from
backend to frontend to report number of bytes played by the
frontend (XENSND_EVT_CUR_POS)
- introduce trigger events for playback control: start/stop/pause/resume
- add "req-" prefix to event-channel and ring-ref to unify naming
of the Xen event channels for requests and events
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Oleksandr Grytsov <oleksandr_grytsov@epam.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: Clemens Ladisch <clemens@ladisch.de>
---
xen/include/public/io/sndif.h | 168 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 164 insertions(+), 4 deletions(-)
diff --git a/xen/include/public/io/sndif.h b/xen/include/public/io/sndif.h
index 667e610fda2b..1a6a1467f253 100644
--- a/xen/include/public/io/sndif.h
+++ b/xen/include/public/io/sndif.h
@@ -41,7 +41,7 @@
* Protocol version
******************************************************************************
*/
-#define XENSND_PROTOCOL_VERSION 1
+#define XENSND_PROTOCOL_VERSION 2
/*
******************************************************************************
@@ -113,6 +113,8 @@
*
* /local/domain/1/device/vsnd/0/0/0/ring-ref = "386"
* /local/domain/1/device/vsnd/0/0/0/event-channel = "15"
+ * /local/domain/1/device/vsnd/0/0/0/evt-ring-ref = "1386"
+ * /local/domain/1/device/vsnd/0/0/0/evt-event-channel = "215"
*
*------------------------------ Stream 1, capture ----------------------------
*
@@ -122,6 +124,8 @@
*
* /local/domain/1/device/vsnd/0/0/1/ring-ref = "384"
* /local/domain/1/device/vsnd/0/0/1/event-channel = "13"
+ * /local/domain/1/device/vsnd/0/0/1/evt-ring-ref = "1384"
+ * /local/domain/1/device/vsnd/0/0/1/evt-event-channel = "213"
*
*------------------------------- PCM device 1 --------------------------------
*
@@ -135,6 +139,8 @@
*
* /local/domain/1/device/vsnd/0/1/0/ring-ref = "387"
* /local/domain/1/device/vsnd/0/1/0/event-channel = "151"
+ * /local/domain/1/device/vsnd/0/1/0/evt-ring-ref = "1387"
+ * /local/domain/1/device/vsnd/0/1/0/evt-event-channel = "351"
*
*------------------------------- PCM device 2 --------------------------------
*
@@ -147,6 +153,8 @@
*
* /local/domain/1/device/vsnd/0/2/0/ring-ref = "389"
* /local/domain/1/device/vsnd/0/2/0/event-channel = "152"
+ * /local/domain/1/device/vsnd/0/2/0/evt-ring-ref = "1389"
+ * /local/domain/1/device/vsnd/0/2/0/evt-event-channel = "452"
*
******************************************************************************
* Backend XenBus Nodes
@@ -292,6 +300,23 @@
* The Xen grant reference granting permission for the backend to map
* a sole page in a single page sized ring buffer.
*
+ *--------------------- Stream Event Transport Parameters ---------------------
+ *
+ * This communication path is used to deliver asynchronous events from backend
+ * to frontend, set up per stream.
+ *
+ * evt-event-channel
+ * Values: <uint32_t>
+ *
+ * The identifier of the Xen event channel used to signal activity
+ * in the ring buffer.
+ *
+ * evt-ring-ref
+ * Values: <uint32_t>
+ *
+ * The Xen grant reference granting permission for the backend to map
+ * a sole page in a single page sized ring buffer.
+ *
******************************************************************************
* STATE DIAGRAMS
******************************************************************************
@@ -439,6 +464,19 @@
#define XENSND_OP_GET_VOLUME 5
#define XENSND_OP_MUTE 6
#define XENSND_OP_UNMUTE 7
+#define XENSND_OP_TRIGGER 8
+
+#define XENSND_OP_TRIGGER_START 0
+#define XENSND_OP_TRIGGER_PAUSE 1
+#define XENSND_OP_TRIGGER_STOP 2
+#define XENSND_OP_TRIGGER_RESUME 3
+
+/*
+ ******************************************************************************
+ * EVENT CODES
+ ******************************************************************************
+ */
+#define XENSND_EVT_CUR_POS 0
/*
******************************************************************************
@@ -455,6 +493,8 @@
#define XENSND_FIELD_VCARD_LONG_NAME "long-name"
#define XENSND_FIELD_RING_REF "ring-ref"
#define XENSND_FIELD_EVT_CHNL "event-channel"
+#define XENSND_FIELD_EVT_RING_REF "evt-ring-ref"
+#define XENSND_FIELD_EVT_EVT_CHNL "evt-event-channel"
#define XENSND_FIELD_DEVICE_NAME "name"
#define XENSND_FIELD_TYPE "type"
#define XENSND_FIELD_STREAM_UNIQUE_ID "unique-id"
@@ -566,9 +606,7 @@
* +----------------+----------------+----------------+----------------+
* | gref_directory | 24
* +----------------+----------------+----------------+----------------+
- * | reserved | 28
- * +----------------+----------------+----------------+----------------+
- * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * | period_sz | 28
* +----------------+----------------+----------------+----------------+
* | reserved | 32
* +----------------+----------------+----------------+----------------+
@@ -578,6 +616,14 @@
* pcm_channels - uint8_t, number of channels of this stream,
* [channels-min; channels-max]
* buffer_sz - uint32_t, buffer size to be allocated, octets
+ * period_sz - uint32_t, event period size, octets
+ * This is the requested value of the period at which frontend would
+ * like to receive XENSND_EVT_CUR_POS notifications from the backend when
+ * stream position advances during playback/capture.
+ * It shows how many octets are expected to be played/captured before
+ * sending such an event.
+ * If set to 0 no XENSND_EVT_CUR_POS events are sent by the backend.
+ *
* gref_directory - grant_ref_t, a reference to the first shared page
* describing shared buffer references. At least one page exists. If shared
* buffer size (buffer_sz) exceeds what can be addressed by this single page,
@@ -592,6 +638,7 @@ struct xensnd_open_req {
uint16_t reserved;
uint32_t buffer_sz;
grant_ref_t gref_directory;
+ uint32_t period_sz;
};
/*
@@ -750,8 +797,36 @@ struct xensnd_rw_req {
*
* The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME,
* XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE.
+ *
+ * Request stream running state change - trigger PCM stream running state
+ * to start, stop, pause or resume:
+ *
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | _OP_TRIGGER | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | type | reserved | 12
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 24
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 28
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * type - uint8_t, XENSND_OP_TRIGGER_XXX value
*/
+struct xensnd_trigger_req {
+ uint8_t type;
+};
+
/*
*---------------------------------- Responses --------------------------------
*
@@ -774,8 +849,51 @@ struct xensnd_rw_req {
* id - uint16_t, copied from the request
* operation - uint8_t, XENSND_OP_* - copied from request
* status - int32_t, response status, zero on success and -XEN_EXX on failure
+ *
+ *----------------------------------- Events ----------------------------------
+ *
+ * Events are sent via a shared page allocated by the front and propagated by
+ * evt-event-channel/evt-ring-ref XenStore entries
+ * All event packets have the same length (32 octets)
+ * All event packets have common header:
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | type | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * id - uint16_t, event id, may be used by front
+ * type - uint8_t, type of the event
+ *
+ *
+ * Current stream position - event from back to front when stream's
+ * playback/capture position has advanced:
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | _EVT_CUR_POS | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | position low 32-bit | 12
+ * +----------------+----------------+----------------+----------------+
+ * | position high 32-bit | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * position - current value of stream's playback/capture position, octets
+ *
*/
+struct xensnd_cur_pos_evt {
+ uint64_t position;
+};
+
struct xensnd_req {
uint16_t id;
uint8_t operation;
@@ -783,6 +901,7 @@ struct xensnd_req {
union {
struct xensnd_open_req open;
struct xensnd_rw_req rw;
+ struct xensnd_trigger_req trigger;
uint8_t reserved[24];
} op;
};
@@ -795,8 +914,49 @@ struct xensnd_resp {
uint8_t reserved1[24];
};
+struct xensnd_evt {
+ uint16_t id;
+ uint8_t type;
+ uint8_t reserved[5];
+ union {
+ struct xensnd_cur_pos_evt cur_pos;
+ uint8_t reserved[24];
+ } op;
+};
+
DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
+/*
+ ******************************************************************************
+ * Back to front events delivery
+ ******************************************************************************
+ * In order to deliver asynchronous events from back to front a shared page is
+ * allocated by front and its granted reference propagated to back via
+ * XenStore entries (evt-ring-ref/evt-event-channel).
+ * This page has a common header used by both front and back to synchronize
+ * access and control event's ring buffer, while back being a producer of the
+ * events and front being a consumer. The rest of the page after the header
+ * is used for event packets.
+ *
+ * Upon reception of an event(s) front may confirm its reception
+ * for either each event, group of events or none.
+ */
+
+struct xensnd_event_page {
+ uint32_t in_cons;
+ uint32_t in_prod;
+ uint8_t reserved[24];
+};
+
+#define XENSND_EVENT_PAGE_SIZE 4096
+#define XENSND_IN_RING_OFFS (sizeof(struct xensnd_event_page))
+#define XENSND_IN_RING_SIZE (XENSND_EVENT_PAGE_SIZE - XENSND_IN_RING_OFFS)
+#define XENSND_IN_RING_LEN (XENSND_IN_RING_SIZE / sizeof(struct xensnd_evt))
+#define XENSND_IN_RING(page) \
+ ((struct xensnd_evt *)((char *)(page) + XENSND_IN_RING_OFFS))
+#define XENSND_IN_RING_REF(page, idx) \
+ (XENSND_IN_RING((page))[(idx) % XENSND_IN_RING_LEN])
+
#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */
/*
--
2.7.4
^ permalink raw reply related [flat|nested] 7+ messages in thread* [Xen-devel][PATCH v2 3/3] sndif: Add explicit back and front parameter negotiation
2018-03-14 16:02 [Xen-devel][PATCH v2 0/3] sndif: add explicit back and front synchronization Oleksandr Andrushchenko
2018-03-14 16:02 ` [Xen-devel][PATCH v2 1/3] sndif: Introduce protocol version Oleksandr Andrushchenko
2018-03-14 16:02 ` [Xen-devel][PATCH v2 2/3] sndif: Add explicit back and front synchronization Oleksandr Andrushchenko
@ 2018-03-14 16:02 ` Oleksandr Andrushchenko
2 siblings, 0 replies; 7+ messages in thread
From: Oleksandr Andrushchenko @ 2018-03-14 16:02 UTC (permalink / raw)
To: alsa-devel, xen-devel, konrad.wilk, tiwai
Cc: andr2000, Oleksandr Andrushchenko
From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
In order to provide explicit stream parameter negotiation between
backend and frontend the following changes are introduced in the protocol:
add XENSND_OP_HW_PARAM_QUERY request to read/update
configuration space for the parameter given: request passes
desired parameter interval (mask) and the response to this request
returns min/max interval (mask) for the parameter to be used.
Parameters supported by this request/response:
- format mask
- sample rate interval
- number of channels interval
- buffer size, interval, frames
- period size, interval, frames
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Takashi Iwai <tiwai@suse.de>
---
xen/include/public/io/sndif.h | 124 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 117 insertions(+), 7 deletions(-)
diff --git a/xen/include/public/io/sndif.h b/xen/include/public/io/sndif.h
index 1a6a1467f253..ff0ba15b0462 100644
--- a/xen/include/public/io/sndif.h
+++ b/xen/include/public/io/sndif.h
@@ -465,12 +465,19 @@
#define XENSND_OP_MUTE 6
#define XENSND_OP_UNMUTE 7
#define XENSND_OP_TRIGGER 8
+#define XENSND_OP_HW_PARAM_QUERY 9
#define XENSND_OP_TRIGGER_START 0
#define XENSND_OP_TRIGGER_PAUSE 1
#define XENSND_OP_TRIGGER_STOP 2
#define XENSND_OP_TRIGGER_RESUME 3
+#define XENSND_OP_HW_PARAM_FORMAT 0
+#define XENSND_OP_HW_PARAM_RATE 1
+#define XENSND_OP_HW_PARAM_BUFFER 2
+#define XENSND_OP_HW_PARAM_PERIOD 3
+#define XENSND_OP_HW_PARAM_CHANNELS 4
+
/*
******************************************************************************
* EVENT CODES
@@ -828,28 +835,127 @@ struct xensnd_trigger_req {
};
/*
+ * Request stream configuration parameter range: request interval or
+ * bit mask of the supported values for the parameter given.
+ *
+ * Sound device configuration for a particular stream is a limited subset
+ * of the multidimensional configuration available on XenStore, for instance,
+ * once frame rate has been selected there is a limited supported range
+ * for sample rates becomes available (which might be the same set configured
+ * on XenStore or less). For example, selecting 96kHz sample rate may limit
+ * number of channels available for such configuration from 4 to 2 etc.
+ * Thus, each call to XENSND_OP_HW_PARAM_QUERY will reduce configuration
+ * space making it possible to iteratively get the final stream configuration,
+ * used in XENSND_OP_OPEN request.
+ *
+ * See response format for this request.
+ *
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | _HW_PARAM_QUERY| reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | param | reserved | 12
+ * +----------------+----------------+----------------+----------------+
+ * | min or mask low 32-bit | 16
+ * +----------------+----------------+----------------+----------------+
+ * | max or mask high 32-bit | 20
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 24
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 28
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 32
+ * +----------------+----------------+----------------+----------------+
+ *
+ * param - uint8_t, XENSND_OP_HW_PARAM_XXX value
+ *
+ * The following parameters' payload treated as interval:
+ * XENSND_OP_HW_PARAM_RATE
+ * XENSND_OP_HW_PARAM_BUFFER
+ * XENSND_OP_HW_PARAM_PERIOD
+ * XENSND_OP_HW_PARAM_CHANNELS
+ *
+ * For interval parameters the payload of the request:
+ * min - uint32_t, minimum value of the parameter
+ * max - uint32_t, maximum value of the parameter
+ *
+ * For the following parameters their min and max values are expressed in
+ * frames:
+ * XENSND_OP_HW_PARAM_BUFFER
+ * XENSND_OP_HW_PARAM_PERIOD
+ * where frame is defined as a product of the number of channels by the
+ * number of octets per one sample.
+ *
+ * The following parameters' payload treated as a bit mask:
+ * XENSND_OP_HW_PARAM_FORMAT
+ *
+ * For mask parameters the payload of the request:
+ * mask - uint64_t, bit mask representing values of the parameter
+ */
+
+struct xensnd_query_hw_param_req {
+ uint8_t param;
+ uint8_t reserved[3];
+ union {
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } interval;
+ uint64_t mask;
+ } val;
+};
+
+/*
*---------------------------------- Responses --------------------------------
*
* All response packets have the same length (32 octets)
*
- * Response for all requests:
+ * All response packets have common header:
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | id | operation | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | status | 8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * id - uint16_t, copied from the request
+ * operation - uint8_t, XENSND_OP_* - copied from request
+ * status - int32_t, response status, zero on success and -XEN_EXX on failure
+ *
+ *
+ * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | operation | reserved | 4
* +----------------+----------------+----------------+----------------+
* | status | 8
* +----------------+----------------+----------------+----------------+
- * | reserved | 12
+ * | min or mask low 32-bit | 12
+ * +----------------+----------------+----------------+----------------+
+ * | max or mask high 32-bit | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 32
* +----------------+----------------+----------------+----------------+
*
- * id - uint16_t, copied from the request
- * operation - uint8_t, XENSND_OP_* - copied from request
- * status - int32_t, response status, zero on success and -XEN_EXX on failure
- *
+ * The payload meaning is the same as in the corresponing HW parameter
+ * request: see XENSND_OP_HW_PARAM_QUERY for details.
+ */
+
+union xensnd_query_hw_param_resp {
+ struct {
+ uint32_t min;
+ uint32_t max;
+ } interval;
+ uint64_t mask;
+};
+
+/*
*----------------------------------- Events ----------------------------------
*
* Events are sent via a shared page allocated by the front and propagated by
@@ -902,6 +1008,7 @@ struct xensnd_req {
struct xensnd_open_req open;
struct xensnd_rw_req rw;
struct xensnd_trigger_req trigger;
+ struct xensnd_query_hw_param_req hw_param;
uint8_t reserved[24];
} op;
};
@@ -911,7 +1018,10 @@ struct xensnd_resp {
uint8_t operation;
uint8_t reserved;
int32_t status;
- uint8_t reserved1[24];
+ union {
+ union xensnd_query_hw_param_resp hw_param;
+ uint8_t reserved1[24];
+ } resp;
};
struct xensnd_evt {
--
2.7.4
^ permalink raw reply related [flat|nested] 7+ messages in thread