Messages in this thread | | | Date | Mon, 8 Nov 1999 11:31:12 -0500 (EST) | From | "Tony E. Bennett" <> | Subject | Re: locking user memory and kiobuf |
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>>>>> "Alan" == Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
>> kiobuf sounds perfect for a problem we have. Currently I use mmap() to map >> pages from __get_free_pages() into user space for dma. This is not totally >> satisfactory, tho, in part because the resulting group of pages is not mapped >> contiguously into kernel.
Alan> If you have a situation where that is hard to handle you can vmalloc a block Alan> of memory then map that into user space. drivers/char/bttv.c does it. Its Alan> ugly and bttv needs to switch to kiovecs in 2.3.x if I get time.
Is vmalloc'd memory locked down and thus suitable for dma? Somehow I thought it was paged...
>> Since we're going to ship a driver to customers, we can't use kiobuf unless >> it is standard part of the kernel.
Alan> Whose kernel 8)
Why, everybody's of course :-)
--tony
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