callback or notification from kernel to user space
I am working on a device driver. It is no problem to access driver from user space to call ioctl, read and write. But how can I issue a callback from kernel to user application? For example, my driver in kernel space receives some packets from hardware and need to pass the data to the application in user space, is it possible to pass a callback function from user space to kernel, so that the kernel can call the callback function in user space? Or using other mechanism to let kernel notifies user applicaitons asynchronously?