Accessing high PCI memory

Dave Newman (dnewman@skepsis.com)
Mon, 9 Nov 1998 19:21:02 -0500 (EST)

I am writing a device driver and the "Linux Device Drivers"
book has left me with a question that I can't find the answer
to. It is a PCI device so probing the device and reading
the configuration registers is easy enough but I run into
problems when trying to read from the memory on-board.
The device has a 4k region of 32bit registers at 0xfdbfe000.
When I try to use read[bwl]() I get a segmentation fault
and in[bwl]() always returns 0xffffffff. The book talks about
remapping PCI memory but only in terms of making it available
to user-space. I only want to access these locations from
within the driver.

This _has_ to be a FAQ, but I can't find the answer anywhere.

-Dave

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