[PATCH] drm: Remove PageReserved manipulation from drm_pci_alloc

[Chris Wilson]

Quoting Daniel Vetter (2020-02-02 16:43:06)
> On Sun, Feb 02, 2020 at 04:10:09PM +0000, Chris Wilson wrote:
> > drm_pci_alloc/drm_pci_free are very thin wrappers around the core dma
> > facilities, and we have no special reason within the drm layer to behave
> > differently. In particular, since
> > 
> > commit de09d31dd38a50fdce106c15abd68432eebbd014
> > Author: Kirill A. Shutemov <kirill.shutemov at linux.intel.com>
> > Date:   Fri Jan 15 16:51:42 2016 -0800
> > 
> >     page-flags: define PG_reserved behavior on compound pages
> > 
> >     As far as I can see there's no users of PG_reserved on compound pages.
> >     Let's use PF_NO_COMPOUND here.
> > 
> > it has been illegal to combine GFP_COMP with SetPageReserved, so lets
> > stop doing both and leave the dma layer to its own devices.
> > 
> > Reported-by: Taketo Kabe
> > Closes: https://gitlab.freedesktop.org/drm/intel/issues/1027
> > Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages")
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: <stable at vger.kernel.org> # v4.5+
> 
> Given that after your i915 patch only mga and r128 still use this I think
> deleting code is the best action here.

drm_bufs.c has a little sting in its tail with the inclusion of the
drm_dma_handle struct in its seglist. Certainly after removing r128 we
can remove the EXPORT_SYMBOL and make it internal.
-Chris