I suspect we probably set this incorrectly; we have some platforms where
there is merely an offset between the phys address and the bus address.
For these, I think we want to set this to 1.
Other platforms require the dma functions to allocate a new buffer
and copy the data to work around buggy "wont fix" errata (eg, new buffer
below 1MB) and for these I think we want to leave this at 0.
It is rather unfortunate that this got called "PCI_xxx" since it has
been used in a non pci-bus manner in (eg) the scsi layer.
Also note that I have platforms where the dma_mask is a real mask not
"a set of zeros followed by a set of ones from MSB to LSB." I can
see this breaking the block layer if PCI_DMA_BUS_IS_PHYS is defined
to one. 8/
--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux
http://www.arm.linux.org.uk/personal/aboutme.html
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