apps: add responder part of the no copy example

Add the ping responder that uses the nocpy API to process the message
outside of the receive callback.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>

apps/examples/nocopy_echo/CMakeLists.txt

@@ -15,9 +15,13 @@ collector_list (_deps PROJECT_LIB_DEPS)
 
 set (OPENAMP_LIB open_amp)
 
-foreach (_app pmsg-nocopy-ping)
+foreach (_app rpmsg-nocopy-ping rpmsg-nocopy-echo)
   collector_list (_sources APP_COMMON_SOURCES)
+  if (${_app} STREQUAL "rpmsg-nocopy-ping")
     list (APPEND _sources "${CMAKE_CURRENT_SOURCE_DIR}/rpmsg-nocopy-ping.c")
+  elseif (${_app} STREQUAL "rpmsg-nocopy-echo")
+    list (APPEND _sources "${CMAKE_CURRENT_SOURCE_DIR}/rpmsg-nocopy-echo.c")
+  endif (${_app} STREQUAL "rpmsg-nocopy-ping")
 
   if (WITH_SHARED_LIB)
     add_executable (${_app}-shared ${_sources})

apps/examples/nocopy_echo/rpmsg-nocopy-echo.c

@@ -0,0 +1,168 @@
+/*
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2020, STMicroelectronics
+ */
+
+/*
+ * This is a sample demonstration application that showcases usage of rpmsg
+ * This application is meant to run on the remote CPU running baremetal code.
+ * This application echoes back data that was sent to it by the master core.
+ */
+
+#include <stdio.h>
+#include <openamp/open_amp.h>
+#include <metal/alloc.h>
+#include "platform_info.h"
+#include "rpmsg-echo.h"
+
+#define SHUTDOWN_MSG	0xEF56A55A
+
+#define LPRINTF(format, ...) printf(format, ##__VA_ARGS__)
+#define LPERROR(format, ...) LPRINTF("ERROR: " format, ##__VA_ARGS__)
+
+static struct rpmsg_endpoint lept;
+static int shutdown_req;
+
+struct rpmsg_rcv_msg {
+	void *data;
+	size_t len;
+	struct rpmsg_endpoint *ept;
+	struct rpmsg_rcv_msg *next;
+};
+
+struct rpmsg_rcv_msg *rpmsg_list;
+
+/*-----------------------------------------------------------------------------
+ *  RPMSG endpoint callbacks
+ *-----------------------------------------------------------------------------
+ */
+static int rpmsg_endpoint_cb(struct rpmsg_endpoint *ept, void *data, size_t len,
+			     uint32_t src, void *priv)
+{
+	(void)src;
+	(void)priv;
+	struct rpmsg_rcv_msg *rpmsg_node, *p_msg;
+
+	/* On reception of a shutdown we signal the application to terminate */
+	if ((*(unsigned int *)data) == SHUTDOWN_MSG) {
+		LPRINTF("shutdown message is received.\r\n");
+		shutdown_req = 1;
+		return RPMSG_SUCCESS;
+	}
+
+	rpmsg_node = metal_allocate_memory(sizeof(*rpmsg_node));
+	if (!rpmsg_node) {
+		LPERROR("rpmsg_node allocation failed\r\n");
+		return -1;
+	}
+	rpmsg_hold_rx_buffer(ept, data);
+	rpmsg_node->ept = ept;
+	rpmsg_node->data = data;
+	rpmsg_node->len = len;
+	rpmsg_node->next = NULL;
+
+	if (!rpmsg_list)
+		rpmsg_list = rpmsg_node;
+	else {
+		p_msg = rpmsg_list;
+		while (p_msg->next)
+			p_msg = p_msg->next;
+		p_msg->next = rpmsg_node;
+	}
+
+	return RPMSG_SUCCESS;
+}
+
+static void rpmsg_service_unbind(struct rpmsg_endpoint *ept)
+{
+	(void)ept;
+	LPRINTF("unexpected Remote endpoint destroy\r\n");
+	shutdown_req = 1;
+}
+
+/*-----------------------------------------------------------------------------
+ *  Application
+ *-----------------------------------------------------------------------------
+ */
+int app(struct rpmsg_device *rdev, void *priv)
+{
+	int ret;
+	struct rpmsg_rcv_msg *rpmsg_node;
+
+	/* Initialize RPMSG framework */
+	LPRINTF("Try to create rpmsg endpoint.\r\n");
+
+	rpmsg_list = NULL;
+	ret = rpmsg_create_ept(&lept, rdev, RPMSG_SERVICE_NAME,
+			       RPMSG_ADDR_ANY, RPMSG_ADDR_ANY,
+			       rpmsg_endpoint_cb,
+			       rpmsg_service_unbind);
+	if (ret) {
+		LPERROR("Failed to create endpoint.\r\n");
+		return -1;
+	}
+
+	LPRINTF("Successfully created rpmsg endpoint.\r\n");
+	while (1) {
+		platform_poll(priv);
+		/* we got a shutdown request, exit */
+		if (shutdown_req) {
+			break;
+		}
+		while (rpmsg_list) {
+			/* Send data back to master */
+			ret = rpmsg_send(rpmsg_list->ept, rpmsg_list->data,
+					 rpmsg_list->len);
+			if (ret < 0) {
+				LPERROR("rpmsg_send failed\r\n");
+				return ret;
+			}
+			rpmsg_release_rx_buffer(rpmsg_list->ept,
+						rpmsg_list->data);
+			rpmsg_node = rpmsg_list;
+			rpmsg_list = rpmsg_list->next;
+			metal_free_memory(rpmsg_node);
+		}
+	}
+	rpmsg_destroy_ept(&lept);
+
+	return 0;
+}
+
+/*-----------------------------------------------------------------------------
+ *  Application entry point
+ *-----------------------------------------------------------------------------
+ */
+int main(int argc, char *argv[])
+{
+	void *platform;
+	struct rpmsg_device *rpdev;
+	int ret;
+
+	LPRINTF("Starting application...\r\n");
+
+	/* Initialize platform */
+	ret = platform_init(argc, argv, &platform);
+	if (ret) {
+		LPERROR("Failed to initialize platform.\r\n");
+		ret = -1;
+	} else {
+		rpdev = platform_create_rpmsg_vdev(platform, 0,
+						   VIRTIO_DEV_SLAVE,
+						   NULL, NULL);
+		if (!rpdev) {
+			LPERROR("Failed to create rpmsg virtio device.\r\n");
+			ret = -1;
+		} else {
+			app(rpdev, platform);
+			platform_release_rpmsg_vdev(rpdev, platform);
+			ret = 0;
+		}
+	}
+
+	LPRINTF("Stopping application...\r\n");
+	platform_cleanup(platform);
+
+	return ret;
+}