> Date: Mon, 3 Dec 2012 17:49:49 +0100
> From: Martin Pieuchot <[email protected]>
>
> On 28/11/12(Wed) 16:49, Mark Kettenis wrote:
> > > Date: Tue, 27 Nov 2012 15:02:31 +0100
> > > From: Martin Pieuchot <[email protected]>
> > >
> > > While working on drm support for macppc that makes use of non-cached
> > > memory I found that some platforms (amd64, i386, powerpc) use the MD
> > > PMAP_NOCACHE flag where others (sparc, sparc64, solbourne) use PMAP_NC
> > > for the same purpose.
> > >
> > > Because I'd like to use this flag in the drm code and for coherency
> > > the diff below rename PMAP_NOCACHE into PMAP_NC.
> > >
> > > Tested on macppc and amd64, ok?
> >
> > Hi Martin,
> >
> > These flags are not really supposed to be used in MI code. So I don't
> > think the drm and agp code should use these flags, at least not
> > directly. Fortunately doing so isn't really necessary, at least for
> > the agp stuff. There we can do something like:
>
> Following your suggestion, here's a diff that implements the
> BUS_DMA_NOCACHE flag for bus_dmamem_mmap(9) on macppc. Ok?
ok kettenis@
> Martin
>
> Index: macppc/dma.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/macppc/macppc/dma.c,v
> retrieving revision 1.36
> diff -u -p -r1.36 dma.c
> --- macppc/dma.c 30 Aug 2012 18:14:26 -0000 1.36
> +++ macppc/dma.c 3 Dec 2012 11:56:09 -0000
> @@ -522,7 +522,10 @@ paddr_t
> _dmamem_mmap(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs, off_t off,
> int prot, int flags)
> {
> - int i;
> + int i, pmapflags = 0;
> +
> + if (flags & BUS_DMA_NOCACHE)
> + pmapflags |= PMAP_NOCACHE;
>
> for (i = 0; i < nsegs; i++) {
> #ifdef DIAGNOSTIC
> @@ -539,7 +542,7 @@ _dmamem_mmap(bus_dma_tag_t t, bus_dma_se
> continue;
> }
>
> - return (segs[i].ds_addr + off);
> + return ((segs[i].ds_addr + off) | pmapflags);
> }
>
> /* Page not found. */
