Add additional error logging in NPU driver

To make it easier to distinguish where an error occurred in the NPU
driver, additional logging has been added to the error cases.

Change-Id: I9d744e7adf3ba3098d456d1f3c2859aa0ce66de4
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>
diff --git a/kernel/common/ethosu_buffer.c b/kernel/common/ethosu_buffer.c
index cf41b8d..519e270 100644
--- a/kernel/common/ethosu_buffer.c
+++ b/kernel/common/ethosu_buffer.c
@@ -139,12 +139,18 @@
 	struct ethosu_buffer *buf;
 	int ret = -ENOMEM;
 
-	if (!size)
+	if (!size) {
+		dev_err(dev, "Buffer create. Invalid zero size");
+
 		return -EINVAL;
+	}
 
 	buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL);
-	if (!buf)
+	if (!buf) {
+		dev_err(dev, "Buffer create. Failed to allocate struct");
+
 		return -ENOMEM;
+	}
 
 	buf->dev = dev;
 	kref_init(&buf->kref);
@@ -152,13 +158,20 @@
 	buf->dma_mem = ethosu_dma_mem_alloc(dev, size);
 	if (IS_ERR(buf->dma_mem)) {
 		ret = PTR_ERR(buf->dma_mem);
+		dev_err(dev,
+			"Buffer create. Failed to allocate DMA memory. ret=%d",
+			ret);
 		goto free_buf;
 	}
 
 	ret = anon_inode_getfd("ethosu-buffer", &ethosu_buffer_fops, buf,
 			       O_RDWR | O_CLOEXEC);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(dev,
+			"Buffer create. Failed to get file descriptor. ret=%d",
+			ret);
 		goto free_dma;
+	}
 
 	buf->file = fget(ret);
 	buf->file->f_mode |= FMODE_LSEEK;
diff --git a/kernel/common/ethosu_dma_mem.c b/kernel/common/ethosu_dma_mem.c
index 0e05978..fd444d2 100644
--- a/kernel/common/ethosu_dma_mem.c
+++ b/kernel/common/ethosu_dma_mem.c
@@ -35,18 +35,27 @@
 {
 	struct ethosu_dma_mem *dma_mem;
 
-	if (!size)
+	if (!size) {
+		dev_err(dev, "DMA mem alloc. Invalid zero size");
+
 		return ERR_PTR(-EINVAL);
+	}
 
 	dma_mem = devm_kzalloc(dev, sizeof(*dma_mem), GFP_KERNEL);
-	if (!dma_mem)
+	if (!dma_mem) {
+		dev_err(dev,
+			"DMA mem alloc. Failed to allocate struct");
+
 		return ERR_PTR(-ENOMEM);
+	}
 
 	dma_mem->dev = dev;
 	dma_mem->size = size;
 	dma_mem->cpu_addr = dma_alloc_coherent(dev, size, &dma_mem->dma_addr,
 					       GFP_KERNEL);
 	if (!dma_mem->cpu_addr) {
+		dev_err(dev, "DMA mem alloc. Failed to allocate 0x%02zx bytes",
+			size);
 		memset(dma_mem, 0, sizeof(*dma_mem));
 		devm_kfree(dev, dma_mem);
 
diff --git a/kernel/rpmsg/ethosu_rpmsg_cancel_inference.c b/kernel/rpmsg/ethosu_rpmsg_cancel_inference.c
index 5fa7515..b07c0ec 100644
--- a/kernel/rpmsg/ethosu_rpmsg_cancel_inference.c
+++ b/kernel/rpmsg/ethosu_rpmsg_cancel_inference.c
@@ -83,8 +83,11 @@
 		devm_kzalloc(dev,
 			     sizeof(struct ethosu_rpmsg_cancel_inference),
 			     GFP_KERNEL);
-	if (!cancellation)
+	if (!cancellation) {
+		dev_err(dev, "Cancel inference. Failed to allocate struct");
+
 		return -ENOMEM;
+	}
 
 	/* increase ref count on the inference we are refering to */
 	ethosu_rpmsg_inference_get(inf);
diff --git a/kernel/rpmsg/ethosu_rpmsg_inference.c b/kernel/rpmsg/ethosu_rpmsg_inference.c
index b6288ef..dd88a8a 100644
--- a/kernel/rpmsg/ethosu_rpmsg_inference.c
+++ b/kernel/rpmsg/ethosu_rpmsg_inference.c
@@ -278,16 +278,20 @@
 
 	if (uapi->ifm_count > ETHOSU_FD_MAX ||
 	    uapi->ofm_count > ETHOSU_FD_MAX) {
-		dev_warn(dev,
-			 "Too many IFM and/or OFM buffers for inference. ifm_count=%u, ofm_count=%u",
-			 uapi->ifm_count, uapi->ofm_count);
+		dev_err(dev,
+			"Inference create. Too many IFM and/or OFM buffers for inference. ifm_count=%u, ofm_count=%u",
+			uapi->ifm_count, uapi->ofm_count);
 
 		return -EFAULT;
 	}
 
 	inf = devm_kzalloc(dev, sizeof(*inf), GFP_KERNEL);
-	if (!inf)
+	if (!inf) {
+		dev_err(dev,
+			"Inference create. Failed to allocate struct");
+
 		return -ENOMEM;
+	}
 
 	inf->dev = dev;
 	inf->mailbox = mailbox;
@@ -308,6 +312,9 @@
 		inf->ifm[i] = ethosu_buffer_get_from_fd(uapi->ifm_fd[i]);
 		if (IS_ERR(inf->ifm[i])) {
 			ret = PTR_ERR(inf->ifm[i]);
+			dev_err(dev,
+				"Inference create. Failed to get IFM buffer%u ret=%d",
+				i, ret);
 			goto put_ifm;
 		}
 
@@ -319,6 +326,9 @@
 		inf->ofm[i] = ethosu_buffer_get_from_fd(uapi->ofm_fd[i]);
 		if (IS_ERR(inf->ofm[i])) {
 			ret = PTR_ERR(inf->ofm[i]);
+			dev_err(dev,
+				"Inference create. Failed to get OFM buffer%u ret=%d",
+				i, ret);
 			goto put_ofm;
 		}
 
@@ -353,8 +363,13 @@
 	ret = fd = anon_inode_getfd("ethosu-inference",
 				    &ethosu_rpmsg_inference_fops,
 				    inf, O_RDWR | O_CLOEXEC);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(dev,
+			"Inference create. Failed to get file descriptor. ret=%d",
+			ret);
+
 		goto put_net;
+	}
 
 	/* Store pointer to file structure */
 	inf->file = fget(ret);
diff --git a/kernel/rpmsg/ethosu_rpmsg_network.c b/kernel/rpmsg/ethosu_rpmsg_network.c
index 38d7db2..cf36f2d 100644
--- a/kernel/rpmsg/ethosu_rpmsg_network.c
+++ b/kernel/rpmsg/ethosu_rpmsg_network.c
@@ -108,7 +108,7 @@
 	case ETHOSU_IOCTL_NETWORK_INFO: {
 		struct ethosu_uapi_network_info uapi = { 0 };
 
-		dev_dbg(dev, "Network ioctl: Network info. net=0x%pK\n", net);
+		dev_dbg(dev, "Network ioctl: Network info. net=0x%pK", net);
 
 		ret = ethosu_rpmsg_network_info_request(dev, net->mailbox, net,
 							&uapi);
@@ -122,12 +122,14 @@
 		struct ethosu_uapi_inference_create uapi;
 
 		if (copy_from_user(&uapi, udata, sizeof(uapi))) {
+			dev_err(dev,
+				"Network ioctl: Failed to copy inference request");
 			ret = -EFAULT;
 			break;
 		}
 
 		dev_dbg(dev,
-			"Network ioctl: Inference. ifm_fd=%u, ofm_fd=%u\n",
+			"Network ioctl: Inference. ifm_fd=%u, ofm_fd=%u",
 			uapi.ifm_fd[0], uapi.ofm_fd[0]);
 
 		ret = ethosu_rpmsg_inference_create(dev, net->mailbox, net,
@@ -156,8 +158,11 @@
 	int ret;
 
 	net = devm_kzalloc(dev, sizeof(*net), GFP_KERNEL);
-	if (!net)
+	if (!net) {
+		dev_err(dev, "Network create. Failed to allocate struct");
+
 		return -ENOMEM;
+	}
 
 	net->dev = dev;
 	net->mailbox = mailbox;
@@ -166,13 +171,15 @@
 	switch (uapi->type) {
 	case ETHOSU_UAPI_NETWORK_USER_BUFFER:
 		if (!uapi->network.data_ptr) {
-			dev_err(dev, "Invalid network data ptr\n");
+			dev_err(dev,
+				"Network create. Invalid network data ptr");
 			ret = -EINVAL;
 			goto free_net;
 		}
 
 		if (!uapi->network.size) {
-			dev_err(dev, "Invalid network data size\n");
+			dev_err(dev,
+				"Network create. Invalid network data size");
 			ret = -EINVAL;
 			goto free_net;
 		}
@@ -180,20 +187,29 @@
 		net->dma_mem = ethosu_dma_mem_alloc(dev, uapi->network.size);
 		if (IS_ERR(net->dma_mem)) {
 			ret = PTR_ERR(net->dma_mem);
+			dev_err(dev,
+				"Network create. Failed to allocate DMA memory. ret=%d",
+				ret);
 			goto free_net;
 		}
 
 		data = u64_to_user_ptr(uapi->network.data_ptr);
 		ret = copy_from_user(net->dma_mem->cpu_addr, data,
 				     uapi->network.size);
-		if (ret)
+		if (ret) {
+			dev_err(dev,
+				"Network create. Failed to copy network data from user buffer. ret=%d",
+				ret);
 			goto free_dma_mem;
+		}
 
 		break;
 	case ETHOSU_UAPI_NETWORK_INDEX:
 		net->index = uapi->index;
 		break;
 	default:
+		dev_err(dev, "Network create. Invalid buffer type. type=%u",
+			uapi->type);
 		ret = -EINVAL;
 		goto free_net;
 	}
@@ -201,8 +217,12 @@
 	ret = anon_inode_getfd("ethosu-network", &ethosu_rpmsg_network_fops,
 			       net,
 			       O_RDWR | O_CLOEXEC);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(dev,
+			"Network create. Failed to get file descriptor. ret=%d",
+			ret);
 		goto free_dma_mem;
+	}
 
 	net->file = fget(ret);
 	fput(net->file);
diff --git a/kernel/rpmsg/ethosu_rpmsg_network_info.c b/kernel/rpmsg/ethosu_rpmsg_network_info.c
index 36b6290..2445a09 100644
--- a/kernel/rpmsg/ethosu_rpmsg_network_info.c
+++ b/kernel/rpmsg/ethosu_rpmsg_network_info.c
@@ -73,8 +73,12 @@
 	info->msg.fail = ethosu_rpmsg_network_info_fail;
 
 	ret = ethosu_rpmsg_mailbox_register(mailbox, &info->msg);
-	if (ret < 0)
+	if (ret < 0) {
+		dev_err(dev,
+			"Network info create. Failed to register message in mailbox. ret=%d",
+			ret);
 		goto kfree;
+	}
 
 	/* Get reference to network */
 	ethosu_rpmsg_network_get(info->net);