kiobufs and highmem

From: William Waddington (waddington@tahomatech.com)
Date: Wed Jul 17 2002 - 13:15:22 EST

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Hello All,

I have a 2.4.x char driver which works fine, except in boxes with lots of
memory.

user_buffer -> write() -> map_user_kiobuf() -> pci_map_sg() -> Pci DMA

I'm using the .page/.offset version of the scatterlist, but in the HIGHMEM case,
map_user_kiobuf() seems to return peculiar page addresses.

What is the state of kiobufs/HIGHMEM in 2.4.x? Do I need to implement
a bounce buffer in the driver? Some email correspondence indicates so,
but I would be grateful for a definitive word from the kernel folks.

TIA,
Bill Waddington

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Next message: Daniel Phillips: "Re: [patch 10/13] remove add_to_page_cache_unique()"
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