Quoting Mike DeKoker <mdekoker@yahoo.com>: > > I am developing a module for a PCI device. In order to get large enough > DMA buffers, I am reserving the upper N megabytes of RAM (via the > kernel parameter "mem=") and using ioremap to get at the buffer from > within the kernel. This is all fine and dandy, I can do DMA transfers > to/from my device just fine. My question is, is it possible to map > this DMA buffer into user space? > > For smaller, kmalloc'd DMA buffers I can map into user space easily by > manually returning the correct page with VM no_page operation. It > doesn't look like I can do this using reserved buffers because the > page structures don't appear to be valid. (Reserved buffer page indices > >= max_mapnr). > > Thanks for your time, > Mike DeKoker > Signatec, Inc. > I think you will have to implement mmap() for your driver.Check Linux Device Drivers, Rubini for more information. -sridhar -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
