Ed Okerson wrote:
Is it possible to mmap an address in KSEG1 so a user space app can read/write to an IO device uncached?
It depends on your definition of 'possible'. The mips32/64 architecture specification has a 'C' field in the EntryLo register that controls cachability, so given an appropriate device driver it should be doable.
Calling __ioremap() with the appropriate flags should allow you to set the 'C' bits.
Depending on your requirements, you might be able to get by using /dev/mem and some 'sync' instructions, instead of establishing an uncached mapping.
David Daney
