From: Alan Cox <alan@lxorguk.ukuu.org.uk>
Date: 30 Sep 2002 13:54:11 +0100
On Mon, 2002-09-30 at 01:53, David S. Miller wrote:
> EISA/ISA DMA is defined as using a hwdev of NULL or requiring
> <16MB address, he is preserving GFP_DMA in those cases.
Firstly the DMA mask on x86 can't be below 24bits, we don't support
allocation from a smaller zone.
Understood.
Secondly what about PCI for 25-31bits -
there we do need to force gfp_dma to have any chance of getting the
right pages
Look at what his code does after the GFP_DMA setting, it goes
a non-GFP_DMA setting, and if the 25-31 bits case is not satisfied
it backs down to GFP_DMA.
Giving the page allocator a mask argument does sound a lot nicer
It's pretty simple to implement too since we do have page_to_phys.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Sep 30 2002 - 22:00:47 EST