Re: Proposal: Eliminate GFP_DMA

[Russell King <rmk@arm.linux.org.uk>]

On Fri, Feb 28, 2003 at 09:44:14PM +0600, Dmitry A. Fedorov wrote:
> On 28 Feb 2003, Alan Cox wrote:
> > On Fri, 2003-02-28 at 14:12, Matthew Wilcox wrote:
> > > i'm not the kind of person who just changes the header file and breaks all
> > > the drivers.  plan:
> > > 
> > >  - Add the GFP_ATOMIC_DMA & GFP_KERNEL_DMA definitions
> > >  - Change the drivers
> > >  - Delete the GFP_DMA definition
> > 
> > Needless pain for people maintaining cross release drivers. Save it for
> > 2.7 where we should finally do the honourable deed given x86-64 may well
> > be mainstream, and simply remove GFP_DMA and expect people to use 
> > pci_*
> 
> But why drivers of ISA bus devices with DMA should use pci_* functions?
> 
> I'm personally wouldn't have too much pain with GFP_DMA because I have
> compatibility headers and proposed change for them is tiny.

Umm, question - I've seen ISA bridges with the ability to perform 32-bit
DMA using the ISA DMA controllers.  AFAIK, Linux doesn't make use of this
feature, except on ARM PCI systems with ISA bridges.  Is there a reason
why this isn't used on x86 hardware?

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html