Re: Proposal: Eliminate GFP_DMA

[Martin J. Bligh]

>> > > umm.  are you volunteering to convert drivers/net/macmace.c to the pci_*
>> > > API then?  also, GFP_DMA is used on, eg, s390 to get memory below 2GB and
>> > > on ia64 to get memory below 4GB.
>> > 
>> > The ia64 is a fine example of how broken it is. People have to hack around 
>> > with GFP_DMA meaning different things on ia64 to everything else. It needs
>> > to die. 
>> 
>> At least on x86-64 it is still needed when you need have some hardware
>> with address limits < 4GB (e.g. an 24bit soundcard)
>> 
>> pci_* on K8 only allows address mask 0xffffffff or unlimited.
> 
> That's a bit broken...  I have an ALS4000 PCI soundcard that is a 24-bit
> soundcard.  pci_set_dma_mask should support 24-bits accordingly,
> otherwise it's a bug in your platform implementation...  Nobody will be
> able to use certain properly-written drivers on your platform otherwise.

If we're going to really sort this out, would be nice to just pass an upper
bound for an address to __alloc_pages, instead of a simple bitmask ;-)

M.