From: Daniel Vetter <daniel@ffwll.ch>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [PATCH] drm: remove pgprot_decrypted() before calls to io_remap_pfn_range()
Date: Tue, 10 Nov 2020 13:54:52 +0100 [thread overview]
Message-ID: <20201110125452.GG401619@phenom.ffwll.local> (raw)
In-Reply-To: <20201105193554.GP2620339@nvidia.com>
On Thu, Nov 05, 2020 at 03:35:54PM -0400, Jason Gunthorpe wrote:
> On Thu, Nov 05, 2020 at 08:17:46PM +0100, Daniel Vetter wrote:
> > On Thu, Nov 05, 2020 at 01:00:19PM -0400, Jason Gunthorpe wrote:
> > > commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
> > > pgprot_decrypted()") moves the pgprot_decrypted() into
> > > io_remap_pfn_range(). Delete any, now confusing, open coded calls that
> > > directly precede io_remap_pfn_range():
> > >
> > > - drm_io_prot() is only in drm_mmap_locked() to call io_remap_pfn_range()
> > >
> > > - fb_mmap() immediately calls vm_iomap_memory() which is a convenience
> > > wrapper for io_remap_pfn_range()
> > >
> > > Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> > > drivers/gpu/drm/drm_vm.c | 3 ---
> > > drivers/video/fbdev/core/fbmem.c | 5 -----
> > > 2 files changed, 8 deletions(-)
> > >
> > > rc3 will have the dependent patch, this should not be merged to DRM until it
> > > has the rc3 commits.
> > >
> > > There are three other pgprot_decrypted() calls in DRM, I could not figure out
> > > what was what there, but other than very special cases I would expect code to
> > > use io_remap_pfn_range() instead.
> >
> > There's 4 now, I think linux-next added one. It's another io_remap_pfn
> >
> > Of the three you mentioned we have:
> > - ttm and i915 use vm_insert_pfn (and ttm also can do also do pud_mkhuge
> > entries)
>
> You can't insert IO memory with vmf_insert_pfn_pmd_prot() (it
> doesn't set the special flag) so why does it need decrypted?
Well, see the other thread, we do ... :-/
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2020-11-10 12:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 17:00 [PATCH] drm: remove pgprot_decrypted() before calls to io_remap_pfn_range() Jason Gunthorpe
2020-11-05 19:17 ` Daniel Vetter
2020-11-05 19:35 ` Jason Gunthorpe
2020-11-10 12:54 ` Daniel Vetter [this message]
2020-11-10 16:19 ` Daniel Vetter
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