On Wed, Dec 13, 2006 at 10:11:31AM +0530, Nilanjan Roychowdhury wrote: > Hi, > > I am thinking of rewriting few traditional Linux drivers as user space > drivers. The idea is to mmap the hardware register region and then use > them. Other than interrupt dispatching, can anyone tell me what all > other issues I may encounter. The intention to do that is to avoid any > system call overhead and overhead with copy_to_user/ copy_from_user. I > am using an embedded board with no swapping. Any insights will be highly > appreciated. I have just the patches you need in the current -mm tree. They are also on kernel.org, in my directory, and will be announced tomorrow as there are a few minor bugs being cleaned up. You can find them at: http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/driver/uio.patch - for the core patch to the kernel http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/driver/uio-documentation.patch - for documentation on how to use it http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/driver/uio-dummy.patch http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/driver/uio-irq.patch - for two example kernel modules and userspace test tools showing how to use the interface properly. Please let me know if this will do what you need, and if you have any questions about it, please let me know. thanks, greg k-h -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
