Re: Accessing high PCI memory
Philip Blundell (pb@nexus.co.uk)
Tue, 10 Nov 1998 10:40:04 +0100
>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.
You need to use ioremap() to make the region accessible and then you should be
in business. There are plenty of device drivers already in the kernel that
use memory-mapped I/O and you should be able to crib the code from one of
these.
p.
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