1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
index d63441194249..e9f448a5ebb3 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_msg.c
@@ -57,6 +57,8 @@
 
 #define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
 
+#define MAX_USER_MSG_LENGTH	PAGE_SIZE
+
 static u32 vmw_msg_enabled = 1;
 
 enum rpc_msg_type {
@@ -517,3 +519,84 @@ out_open:
 
 	return -EINVAL;
 }
+
+
+/**
+ * vmw_msg_ioctl: Sends and receveives a message to/from host from/to user-space
+ *
+ * Sends a message from user-space to host.
+ * Can also receive a result from host and return that to user-space.
+ *
+ * @dev: Identifies the drm device.
+ * @data: Pointer to the ioctl argument.
+ * @file_priv: Identifies the caller.
+ * Return: Zero on success, negative error code on error.
+ */
+
+int vmw_msg_ioctl(struct drm_device *dev, void *data,
+		  struct drm_file *file_priv)
+{
+	struct drm_vmw_msg_arg *arg =
+		(struct drm_vmw_msg_arg *) data;
+	struct rpc_channel channel;
+	char *msg;
+	int length;
+
+	msg = kmalloc(MAX_USER_MSG_LENGTH, GFP_KERNEL);
+	if (!msg) {
+		DRM_ERROR("Cannot allocate memory for log message.\n");
+		return -ENOMEM;
+	}
+
+	length = strncpy_from_user(msg, (void __user *)((unsigned long)arg->send),
+				   MAX_USER_MSG_LENGTH);
+	if (length < 0 || length >= MAX_USER_MSG_LENGTH) {
+		DRM_ERROR("Userspace message access failure.\n");
+		kfree(msg);
+		return -EINVAL;
+	}
+
+
+	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM)) {
+		DRM_ERROR("Failed to open channel.\n");
+		goto out_open;
+	}
+
+	if (vmw_send_msg(&channel, msg)) {
+		DRM_ERROR("Failed to send message to host.\n");
+		goto out_msg;
+	}
+
+	if (!arg->send_only) {
+		char *reply = NULL;
+		size_t reply_len = 0;
+
+		if (vmw_recv_msg(&channel, (void *) &reply, &reply_len)) {
+			DRM_ERROR("Failed to receive message from host.\n");
+			goto out_msg;
+		}
+		if (reply && reply_len > 0) {
+			if (copy_to_user((void __user *)((unsigned long)arg->receive),
+							 reply, reply_len)) {
+				DRM_ERROR("Failed to copy message to userspace.\n");
+				kfree(reply);
+				goto out_msg;
+			}
+			arg->receive_len = (__u32)reply_len;
+		}
+		kfree(reply);
+	}
+
+	vmw_close_channel(&channel);
+	kfree(msg);
+
+	return 0;
+
+out_msg:
+	vmw_close_channel(&channel);
+out_open:
+	kfree(msg);
+
+	return -EINVAL;
+}
+