[v5,4/9] ASoC: SOF: Implement Probe IPC API

diff --git a/include/sound/sof/header.h b/include/sound/sof/header.h
index bf3edd9c08b4..b79479575cc8 100644
--- a/include/sound/sof/header.h
+++ b/include/sound/sof/header.h
@@ -51,6 +51,7 @@ 
 #define SOF_IPC_GLB_TRACE_MSG			SOF_GLB_TYPE(0x9U)
 #define SOF_IPC_GLB_GDB_DEBUG                   SOF_GLB_TYPE(0xAU)
 #define SOF_IPC_GLB_TEST_MSG			SOF_GLB_TYPE(0xBU)
+#define SOF_IPC_GLB_PROBE			SOF_GLB_TYPE(0xCU)
 
 /*
  * DSP Command Message Types
@@ -102,6 +103,16 @@ 
 #define SOF_IPC_STREAM_VORBIS_PARAMS		SOF_CMD_TYPE(0x010)
 #define SOF_IPC_STREAM_VORBIS_FREE		SOF_CMD_TYPE(0x011)
 
+/* probe */
+#define SOF_IPC_PROBE_INIT			SOF_CMD_TYPE(0x001)
+#define SOF_IPC_PROBE_DEINIT			SOF_CMD_TYPE(0x002)
+#define SOF_IPC_PROBE_DMA_ADD			SOF_CMD_TYPE(0x003)
+#define SOF_IPC_PROBE_DMA_INFO			SOF_CMD_TYPE(0x004)
+#define SOF_IPC_PROBE_DMA_REMOVE		SOF_CMD_TYPE(0x005)
+#define SOF_IPC_PROBE_POINT_ADD		SOF_CMD_TYPE(0x006)
+#define SOF_IPC_PROBE_POINT_INFO		SOF_CMD_TYPE(0x007)
+#define SOF_IPC_PROBE_POINT_REMOVE		SOF_CMD_TYPE(0x008)
+
 /* trace */
 #define SOF_IPC_TRACE_DMA_PARAMS		SOF_CMD_TYPE(0x001)
 #define SOF_IPC_TRACE_DMA_POSITION		SOF_CMD_TYPE(0x002)
diff --git a/sound/soc/sof/Kconfig b/sound/soc/sof/Kconfig
index 827b0ec92522..65c3cfbcb812 100644
--- a/sound/soc/sof/Kconfig
+++ b/sound/soc/sof/Kconfig
@@ -41,6 +41,14 @@  config SND_SOC_SOF_OF
 	  required to enable i.MX8 devices.
 	  Say Y if you need this option. If unsure select "N".
 
+config SND_SOC_SOF_DEBUG_PROBES
+	bool "SOF enable data probing"
+	help
+	  This option enables the data probing feature that can be used to
+	  gather data directly from specific points of the audio pipeline.
+	  Say Y if you want to enable probes.
+	  If unsure, select "N".
+
 config SND_SOC_SOF_DEVELOPER_SUPPORT
 	bool "SOF developer options support"
 	depends on EXPERT
diff --git a/sound/soc/sof/Makefile b/sound/soc/sof/Makefile
index 0a8bc72c28a5..18d7cab9046e 100644
--- a/sound/soc/sof/Makefile
+++ b/sound/soc/sof/Makefile
@@ -2,6 +2,7 @@ 
 
 snd-sof-objs := core.o ops.o loader.o ipc.o pcm.o pm.o debug.o topology.o\
 		control.o trace.o utils.o sof-audio.o
+snd-sof-$(CONFIG_SND_SOC_SOF_DEBUG_PROBES) += probe.o
 
 snd-sof-pci-objs := sof-pci-dev.o
 snd-sof-acpi-objs := sof-acpi-dev.o
diff --git a/sound/soc/sof/intel/hda-ipc.c b/sound/soc/sof/intel/hda-ipc.c
index 1837f66e361f..922052883b0a 100644
--- a/sound/soc/sof/intel/hda-ipc.c
+++ b/sound/soc/sof/intel/hda-ipc.c
@@ -106,7 +106,9 @@  void hda_dsp_ipc_get_reply(struct snd_sof_dev *sdev)
 		ret = reply.error;
 	} else {
 		/* reply correct size ? */
-		if (reply.hdr.size != msg->reply_size) {
+		if (reply.hdr.size != msg->reply_size &&
+			/* getter payload is never known upfront */
+			!(reply.hdr.cmd & SOF_IPC_GLB_PROBE)) {
 			dev_err(sdev->dev, "error: reply expected %zu got %u bytes\n",
 				msg->reply_size, reply.hdr.size);
 			ret = -EINVAL;
diff --git a/sound/soc/sof/probe.c b/sound/soc/sof/probe.c
new file mode 100644
index 000000000000..2b2f3dcfc7e9
--- /dev/null
+++ b/sound/soc/sof/probe.c
@@ -0,0 +1,286 @@ 
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2019-2020 Intel Corporation. All rights reserved.
+//
+// Author: Cezary Rojewski <cezary.rojewski@intel.com>
+//
+
+#include "sof-priv.h"
+#include "probe.h"
+
+/**
+ * sof_ipc_probe_init - initialize data probing
+ * @sdev:		SOF sound device
+ * @stream_tag:		Extractor stream tag
+ * @buffer_size:	DMA buffer size to set for extractor
+ *
+ * Host chooses whether extraction is supported or not by providing
+ * valid stream tag to DSP. Once specified, stream described by that
+ * tag will be tied to DSP for extraction for the entire lifetime of
+ * probe.
+ *
+ * Probing is initialized only once and each INIT request must be
+ * matched by DEINIT call.
+ */
+int sof_ipc_probe_init(struct snd_sof_dev *sdev,
+		u32 stream_tag, size_t buffer_size)
+{
+	struct sof_ipc_probe_dma_add_params *msg;
+	struct sof_ipc_reply reply;
+	size_t size = struct_size(msg, dma, 1);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_INIT;
+	msg->num_elems = 1;
+	msg->dma[0].stream_tag = stream_tag;
+	msg->dma[0].dma_buffer_size = buffer_size;
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
+			&reply, sizeof(reply));
+	kfree(msg);
+	return ret;
+}
+EXPORT_SYMBOL(sof_ipc_probe_init);
+
+/**
+ * sof_ipc_probe_deinit - cleanup after data probing
+ * @sdev:	SOF sound device
+ *
+ * Host sends DEINIT request to free previously initialized probe
+ * on DSP side once it is no longer needed. DEINIT only when there
+ * are no probes connected and with all injectors detached.
+ */
+int sof_ipc_probe_deinit(struct snd_sof_dev *sdev)
+{
+	struct sof_ipc_cmd_hdr msg;
+	struct sof_ipc_reply reply;
+
+	msg.size = sizeof(msg);
+	msg.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_DEINIT;
+
+	return sof_ipc_tx_message(sdev->ipc, msg.cmd, &msg, msg.size,
+			&reply, sizeof(reply));
+}
+EXPORT_SYMBOL(sof_ipc_probe_deinit);
+
+static int sof_ipc_probe_info(struct snd_sof_dev *sdev, unsigned int cmd,
+		void **params, size_t *num_params)
+{
+	struct sof_ipc_probe_info_params msg = {{{0}}};
+	struct sof_ipc_probe_info_params *reply;
+	size_t bytes;
+	int ret;
+
+	*params = NULL;
+	*num_params = 0;
+
+	reply = kzalloc(SOF_IPC_MSG_MAX_SIZE, GFP_KERNEL);
+	if (!reply)
+		return -ENOMEM;
+	msg.rhdr.hdr.size = sizeof(msg);
+	msg.rhdr.hdr.cmd = SOF_IPC_GLB_PROBE | cmd;
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg.rhdr.hdr.cmd, &msg,
+			msg.rhdr.hdr.size, reply, SOF_IPC_MSG_MAX_SIZE);
+	if (ret < 0 || reply->rhdr.error < 0)
+		goto exit;
+
+	if (!reply->num_elems)
+		goto exit;
+
+	bytes = reply->num_elems * sizeof(reply->dma[0]);
+	*params = kmemdup(&reply->dma[0], bytes, GFP_KERNEL);
+	if (!*params) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	*num_params = msg.num_elems;
+
+exit:
+	kfree(reply);
+	return ret;
+}
+
+/**
+ * sof_ipc_probe_dma_info - retrieve list of active injection dmas
+ * @sdev:	SOF sound device
+ * @dma:	Returned list of active dmas
+ * @num_dma:	Returned count of active dmas
+ *
+ * Host sends DMA_INFO request to obtain list of injection dmas it
+ * can use to transfer data over with.
+ *
+ * Note that list contains only injection dmas as there is only one
+ * extractor (dma) and it is always assigned on probing init.
+ * DSP knows exactly where data from extraction probes is going to,
+ * which is not the case for injection where multiple streams
+ * could be engaged.
+ */
+int sof_ipc_probe_dma_info(struct snd_sof_dev *sdev,
+		struct sof_probe_dma **dma, size_t *num_dma)
+{
+	return sof_ipc_probe_info(sdev, SOF_IPC_PROBE_DMA_INFO,
+			(void **)dma, num_dma);
+}
+EXPORT_SYMBOL(sof_ipc_probe_dma_info);
+
+/**
+ * sof_ipc_probe_dma_add - attach to specified dmas
+ * @sdev:	SOF sound device
+ * @dma:	List of streams (dmas) to attach to
+ * @num_dma:	Number of elements in @dma
+ *
+ * Contrary to extraction, injection streams are never assigned
+ * on init. Before attempting any data injection, host is responsible
+ * for specifying streams which will be later used to transfer data
+ * to connected probe points.
+ */
+int sof_ipc_probe_dma_add(struct snd_sof_dev *sdev,
+		struct sof_probe_dma *dma, size_t num_dma)
+{
+	struct sof_ipc_probe_dma_add_params *msg;
+	struct sof_ipc_reply reply;
+	size_t size = struct_size(msg, dma, num_dma);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_dma;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_DMA_ADD;
+	memcpy(&msg->dma[0], dma, size - sizeof(*msg));
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
+			&reply, sizeof(reply));
+	kfree(msg);
+	return ret;
+}
+EXPORT_SYMBOL(sof_ipc_probe_dma_add);
+
+/**
+ * sof_ipc_probe_dma_remove - detach from specified dmas
+ * @sdev:		SOF sound device
+ * @stream_tag:		List of stream tags to detach from
+ * @num_stream_tag:	Number of elements in @stream_tag
+ *
+ * Host sends DMA_REMOVE request to free previously attached stream
+ * from being occupied for injection. Each detach operation should
+ * match equivalent DMA_ADD. Detach only when all probes tied to
+ * given stream have been disconnected.
+ */
+int sof_ipc_probe_dma_remove(struct snd_sof_dev *sdev,
+		unsigned int *stream_tag, size_t num_stream_tag)
+{
+	struct sof_ipc_probe_dma_remove_params *msg;
+	struct sof_ipc_reply reply;
+	size_t size = struct_size(msg, stream_tag, num_stream_tag);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_stream_tag;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_DMA_REMOVE;
+	memcpy(&msg->stream_tag[0], stream_tag, size - sizeof(*msg));
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
+			&reply, sizeof(reply));
+	kfree(msg);
+	return ret;
+}
+EXPORT_SYMBOL(sof_ipc_probe_dma_remove);
+
+/**
+ * sof_ipc_probe_points_info - retrieve list of active probe points
+ * @sdev:	SOF sound device
+ * @desc:	Returned list of active probes
+ * @num_desc:	Returned count of active probes
+ *
+ * Host sends PROBE_POINT_INFO request to obtain list of active probe
+ * points, valid for disconnection when given probe is no longer
+ * required.
+ */
+int sof_ipc_probe_points_info(struct snd_sof_dev *sdev,
+		struct sof_probe_point_desc **desc, size_t *num_desc)
+{
+	return sof_ipc_probe_info(sdev, SOF_IPC_PROBE_POINT_INFO,
+				 (void **)desc, num_desc);
+}
+EXPORT_SYMBOL(sof_ipc_probe_points_info);
+
+/**
+ * sof_ipc_probe_points_add - connect specified probes
+ * @sdev:	SOF sound device
+ * @desc:	List of probe points to connect
+ * @num_desc:	Number of elements in @desc
+ *
+ * Dynamically connects to provided set of endpoints. Immediately
+ * after connection is established, host must be prepared to
+ * transfer data from or to target stream given the probing purpose.
+ *
+ * Each probe point should be removed using PROBE_POINT_REMOVE
+ * request when no longer needed.
+ */
+int sof_ipc_probe_points_add(struct snd_sof_dev *sdev,
+		struct sof_probe_point_desc *desc, size_t num_desc)
+{
+	struct sof_ipc_probe_point_add_params *msg;
+	struct sof_ipc_reply reply;
+	size_t size = struct_size(msg, desc, num_desc);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_desc;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_POINT_ADD;
+	memcpy(&msg->desc[0], desc, size - sizeof(*msg));
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
+			&reply, sizeof(reply));
+	kfree(msg);
+	return ret;
+}
+EXPORT_SYMBOL(sof_ipc_probe_points_add);
+
+/**
+ * sof_ipc_probe_points_remove - disconnect specified probes
+ * @sdev:		SOF sound device
+ * @buffer_id:		List of probe points to disconnect
+ * @num_buffer_id:	Number of elements in @desc
+ *
+ * Removes previously connected probes from list of active probe
+ * points and frees all resources on DSP side.
+ */
+int sof_ipc_probe_points_remove(struct snd_sof_dev *sdev,
+		unsigned int *buffer_id, size_t num_buffer_id)
+{
+	struct sof_ipc_probe_point_remove_params *msg;
+	struct sof_ipc_reply reply;
+	size_t size = struct_size(msg, buffer_id, num_buffer_id);
+	int ret;
+
+	msg = kmalloc(size, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+	msg->hdr.size = size;
+	msg->num_elems = num_buffer_id;
+	msg->hdr.cmd = SOF_IPC_GLB_PROBE | SOF_IPC_PROBE_POINT_REMOVE;
+	memcpy(&msg->buffer_id[0], buffer_id, size - sizeof(*msg));
+
+	ret = sof_ipc_tx_message(sdev->ipc, msg->hdr.cmd, msg, msg->hdr.size,
+			&reply, sizeof(reply));
+	kfree(msg);
+	return ret;
+}
+EXPORT_SYMBOL(sof_ipc_probe_points_remove);
diff --git a/sound/soc/sof/probe.h b/sound/soc/sof/probe.h
new file mode 100644
index 000000000000..45daa5552834
--- /dev/null
+++ b/sound/soc/sof/probe.h
@@ -0,0 +1,85 @@ 
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2019-2020 Intel Corporation. All rights reserved.
+ *
+ * Author: Cezary Rojewski <cezary.rojewski@intel.com>
+ */
+
+#ifndef __SOF_PROBE_H
+#define __SOF_PROBE_H
+
+#include <sound/sof/header.h>
+
+struct snd_sof_dev;
+
+#define SOF_PROBE_INVALID_NODE_ID UINT_MAX
+
+struct sof_probe_dma {
+	unsigned int stream_tag;
+	unsigned int dma_buffer_size;
+} __packed;
+
+enum sof_connection_purpose {
+	SOF_CONNECTION_PURPOSE_EXTRACT = 1,
+	SOF_CONNECTION_PURPOSE_INJECT,
+};
+
+struct sof_probe_point_desc {
+	unsigned int buffer_id;
+	unsigned int purpose;
+	unsigned int stream_tag;
+} __packed;
+
+struct sof_ipc_probe_dma_add_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	struct sof_probe_dma dma[0];
+} __packed;
+
+struct sof_ipc_probe_info_params {
+	struct sof_ipc_reply rhdr;
+	unsigned int num_elems;
+	union {
+		struct sof_probe_dma dma[0];
+		struct sof_probe_point_desc desc[0];
+	};
+} __packed;
+
+struct sof_ipc_probe_dma_remove_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	unsigned int stream_tag[0];
+} __packed;
+
+struct sof_ipc_probe_point_add_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	struct sof_probe_point_desc desc[0];
+} __packed;
+
+struct sof_ipc_probe_point_remove_params {
+	struct sof_ipc_cmd_hdr hdr;
+	unsigned int num_elems;
+	unsigned int buffer_id[0];
+} __packed;
+
+int sof_ipc_probe_init(struct snd_sof_dev *sdev,
+		u32 stream_tag, size_t buffer_size);
+int sof_ipc_probe_deinit(struct snd_sof_dev *sdev);
+int sof_ipc_probe_dma_info(struct snd_sof_dev *sdev,
+		struct sof_probe_dma **dma, size_t *num_dma);
+int sof_ipc_probe_dma_add(struct snd_sof_dev *sdev,
+		struct sof_probe_dma *dma, size_t num_dma);
+int sof_ipc_probe_dma_remove(struct snd_sof_dev *sdev,
+		unsigned int *stream_tag, size_t num_stream_tag);
+int sof_ipc_probe_points_info(struct snd_sof_dev *sdev,
+		struct sof_probe_point_desc **desc, size_t *num_desc);
+int sof_ipc_probe_points_add(struct snd_sof_dev *sdev,
+		struct sof_probe_point_desc *desc, size_t num_desc);
+int sof_ipc_probe_points_remove(struct snd_sof_dev *sdev,
+		unsigned int *buffer_id, size_t num_buffer_id);
+
+#endif