memory address space conversion

Hello all, I ask a while ago a question and received great response. I'm hoping to repeat the experience :) I have a driver that I cannot change the ioctl API to. Unfortunately, it has a peculiar need to return a user-space address based on the physical address. Here is the scenario: user cal

question about user space addressed, mmap, and getting phys address

Hi everyone, Sorry I am not on the list, but I was hoping someone here might be able to help me. I have a design that I cannot change that does the following: 1) Calls mmap on a chunk of memory that the device driver uses to DMA to a video decoder. 2) This chunk of memory is treated as several