[virtmagma] Support for magma_poll

Change-Id: Iba9ad6ec8a6cd735af46c3b9baca8937c41ff3b6

drivers/virtio/virtio_magma.c

diff --git a/drivers/virtio/virtio_magma.c b/drivers/virtio/virtio_magma.c
index 26ed77bb..6d12129 100644
--- a/drivers/virtio/virtio_magma.c
+++ b/drivers/virtio/virtio_magma.c
@@ -1074,6 +1074,45 @@ static int virtmagma_command_magma_wait_semaphores(
 	return virtmagma_check_expected_response_type(request, response);
 }
 
+static int
+	virtmagma_command_magma_poll(struct virtmagma_instance *instance,
+				     struct virtmagma_virtio_command *command)
+{
+	int ret;
+	size_t items_size;
+	struct virtio_magma_poll_ctrl *request = command->request_ptr;
+	struct virtio_magma_poll_resp *response = command->response_ptr;
+
+	if (!COMMAND_OK(command, request, response))
+		return -EINVAL;
+
+	/* reallocate request buffer with enough space for the items */
+	/* note: request->count is used as the byte count */
+	items_size = request->count;
+	command->request_size = sizeof(*request) + items_size;
+	command->request_ptr = kzalloc(command->request_size, GFP_KERNEL);
+	if (!command->request_ptr)
+		return -ENOMEM;
+
+	memcpy(command->request_ptr, request, sizeof(*request));
+	ret = copy_from_user((char *)command->request_ptr + sizeof(*request),
+			     (void *)request->items, items_size);
+	if (ret)
+		return ret;
+
+	ret = vq_out_send_sync(instance->vi, command);
+	if (ret)
+		return ret;
+
+	ret = virtmagma_check_expected_response_type(request, response);
+	if (ret)
+		return ret;
+
+	return copy_to_user((void *)request->items,
+			    (char *)command->request_ptr + sizeof(*request),
+			    items_size);
+}
+
 static int virtmagma_command_magma_read_notification_channel(
 	struct virtmagma_instance *instance,
 	struct virtmagma_virtio_command *command)
@@ -1262,7 +1301,7 @@ int virtmagma_ioctl_magma_command(struct file *filp, void __user *ptr)
 	switch (request_type) {
 	case VIRTIO_MAGMA_CMD_CREATE_CONNECTION2:
 		ret = virtmagma_command_magma_create_connection2(instance,
-								&command);
+								 &command);
 		break;
 	case VIRTIO_MAGMA_CMD_RELEASE_CONNECTION:
 		ret = virtmagma_command_magma_release_connection(instance,
@@ -1302,6 +1341,9 @@ int virtmagma_ioctl_magma_command(struct file *filp, void __user *ptr)
 		ret = virtmagma_command_magma_wait_semaphores(instance,
 							      &command);
 		break;
+	case VIRTIO_MAGMA_CMD_POLL:
+		ret = virtmagma_command_magma_poll(instance, &command);
+		break;
 	case VIRTIO_MAGMA_CMD_READ_NOTIFICATION_CHANNEL:
 		ret = virtmagma_command_magma_read_notification_channel(
 			instance, &command);

include/uapi/linux/virtio_magma.h

diff --git a/include/uapi/linux/virtio_magma.h b/include/uapi/linux/virtio_magma.h
index 451566ea..fcf55b1 100644
--- a/include/uapi/linux/virtio_magma.h
+++ b/include/uapi/linux/virtio_magma.h
@@ -62,6 +62,7 @@ enum virtio_magma_ctrl_type {
 	VIRTIO_MAGMA_CMD_QUERY_RETURNS_BUFFER2 = 0x1031,
 	VIRTIO_MAGMA_CMD_CREATE_CONNECTION2 = 0x1032,
 	VIRTIO_MAGMA_CMD_INITIALIZE_LOGGING = 0x1033,
+	VIRTIO_MAGMA_CMD_POLL = 0x1034,
 	/* magma success responses */
 	VIRTIO_MAGMA_RESP_RELEASE_CONNECTION = 0x2004,
 	VIRTIO_MAGMA_RESP_GET_ERROR = 0x2005,
@@ -107,6 +108,7 @@ enum virtio_magma_ctrl_type {
 	VIRTIO_MAGMA_RESP_QUERY_RETURNS_BUFFER2 = 0x2031,
 	VIRTIO_MAGMA_RESP_CREATE_CONNECTION2 = 0x2032,
 	VIRTIO_MAGMA_RESP_INITIALIZE_LOGGING = 0x2033,
+	VIRTIO_MAGMA_RESP_POLL = 0x2034,
 	/* magma error responses */
 	VIRTIO_MAGMA_RESP_ERR_UNIMPLEMENTED = 0x3001,
 	VIRTIO_MAGMA_RESP_ERR_INTERNAL = 0x3002,
@@ -206,6 +208,8 @@ inline const char* virtio_magma_ctrl_type_string(enum virtio_magma_ctrl_type typ
 		case VIRTIO_MAGMA_RESP_CREATE_CONNECTION2: return "VIRTIO_MAGMA_RESP_CREATE_CONNECTION2";
 		case VIRTIO_MAGMA_CMD_INITIALIZE_LOGGING: return "VIRTIO_MAGMA_CMD_INITIALIZE_LOGGING";
 		case VIRTIO_MAGMA_RESP_INITIALIZE_LOGGING: return "VIRTIO_MAGMA_RESP_INITIALIZE_LOGGING";
+		case VIRTIO_MAGMA_CMD_POLL: return "VIRTIO_MAGMA_CMD_POLL";
+		case VIRTIO_MAGMA_RESP_POLL: return "VIRTIO_MAGMA_RESP_POLL";
 		case VIRTIO_MAGMA_RESP_ERR_UNIMPLEMENTED: return "VIRTIO_MAGMA_RESP_ERR_UNIMPLEMENTED";
 		case VIRTIO_MAGMA_RESP_ERR_INTERNAL: return "VIRTIO_MAGMA_RESP_ERR_INTERNAL";
 		case VIRTIO_MAGMA_RESP_ERR_HOST_DISCONNECTED: return "VIRTIO_MAGMA_RESP_ERR_HOST_DISCONNECTED";
@@ -262,6 +266,7 @@ inline enum virtio_magma_ctrl_type virtio_magma_expected_response_type(enum virt
 		case VIRTIO_MAGMA_CMD_QUERY_RETURNS_BUFFER2: return VIRTIO_MAGMA_RESP_QUERY_RETURNS_BUFFER2;
 		case VIRTIO_MAGMA_CMD_CREATE_CONNECTION2: return VIRTIO_MAGMA_RESP_CREATE_CONNECTION2;
 		case VIRTIO_MAGMA_CMD_INITIALIZE_LOGGING: return VIRTIO_MAGMA_RESP_INITIALIZE_LOGGING;
+		case VIRTIO_MAGMA_CMD_POLL: return VIRTIO_MAGMA_RESP_POLL;
 		default: return VIRTIO_MAGMA_RESP_ERR_INVALID_COMMAND;
 	}
 }
@@ -764,4 +769,16 @@ struct virtio_magma_initialize_logging_resp {
 	__le64 result_return;
 } __attribute((packed));
 
+struct virtio_magma_poll_ctrl {
+	struct virtio_magma_ctrl_hdr hdr;
+	__le64 items;
+	__le32 count;
+	__le64 timeout_ns;
+} __attribute((packed));
+
+struct virtio_magma_poll_resp {
+	struct virtio_magma_ctrl_hdr hdr;
+	__le64 result_return;
+} __attribute((packed));
+
 #endif /* _LINUX_VIRTIO_MAGMA_H */