linux-toradex.git/drivers/gpu/drm/drm_drv.c, branch v3.12.30

drm: allow DRM_IOCTL_VERSION on render-nodes

2013-10-30T04:41:56+00:00

DRM_IOCTL_VERSION is a reliable way to get the driver-name and version
information. It's not related to the interface-version (SET_VERSION ioctl)
so we can safely enable it on render-nodes.

Note that gbm uses udev-BUSID to load the correct mesa driver. However,
the VERSION ioctl should be the more reliable way to do this (in case we
add new DRM-bus drivers which have no BUSID or similar).

Signed-off-by: David Herrmann 
Reviewed-by: Daniel Vetter 
Signed-off-by: Dave Airlie

drm: Prevent overwriting from userspace underallocating core ioctl structs

2013-10-18T06:40:37+00:00

Apply the protections from

commit 1b2f1489633888d4a06028315dc19d65768a1c05
Author: Dave Airlie 
Date:   Sat Aug 14 20:20:34 2010 +1000

    drm: block userspace under allocating buffer and having drivers overwrite it (v2)

to the core ioctl structs as well, for we found one instance where there
is a 32-/64-bit size mismatch and were guilty of writing beyond the end
of the user's buffer.

Signed-off-by: Chris Wilson 
Cc: Dave Airlie 
Reviewed-by: Ville Syrjälä 
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie

drm: implement experimental render nodes

2013-08-29T22:43:57+00:00

Render nodes provide an API for userspace to use non-privileged GPU
commands without any running DRM-Master. It is useful for offscreen
rendering, GPGPU clients, and normal render clients which do not perform
modesetting.

Compared to legacy clients, render clients no longer need any
authentication to perform client ioctls. Instead, user-space controls
render/client access to GPUs via filesystem access-modes on the
render-node. Once a render-node was opened, a client has full access to
the client/render operations on the GPU. However, no modesetting or ioctls
that affect global state are allowed on render nodes.

To prevent privilege-escalation, drivers must explicitly state that they
support render nodes. They must mark their render-only ioctls as
DRM_RENDER_ALLOW so render clients can use them. Furthermore, they must
support clients without any attached master.

If filesystem access-modes are not enough for fine-grained access control
to render nodes (very unlikely, considering the versaitlity of FS-ACLs),
you may still fall-back to fd-passing from server to client (which allows
arbitrary access-control). However, note that revoking access is
currently impossible and unlikely to get implemented.

Note: Render clients no longer have any associated DRM-Master as they are
supposed to be independent of any server state. DRM core highly depends on
file_priv->master to be non-NULL for modesetting/ctx/etc. commands.
Therefore, drivers must be very careful to not require DRM-Master if they
support DRIVER_RENDER.

So far render-nodes are protected by "drm_rnodes". As long as this
module-parameter is not set to 1, a driver will not create render nodes.
This allows us to experiment with the API a bit before we stabilize it.

v2: drop insecure GEM_FLINK to force use of dmabuf

Signed-off-by: David Herrmann 
Signed-off-by: Dave Airlie

drm: move dev data clearing from drm_setup to lastclose

2013-08-19T04:29:41+00:00

We kzalloc this structure, and for real kms devices we should never
loose track of things really.

But ums/legacy drivers rely on the drm core to clean up a bit of cruft
between lastclose and firstopen (i.e. when X is being restarted), so
keep this around. But give it a clear drm_legacy_ prefix and
conditionalize the code on !DRIVER_MODESET.

Cc: David Herrmann 
Signed-off-by: Daniel Vetter 
Reviewed-by: David Herrmann 
Signed-off-by: Dave Airlie

drm: remove procfs code, take 2

2013-08-19T04:29:24+00:00

So almost two years ago I've tried to nuke the procfs code already
once before:

http://lists.freedesktop.org/archives/dri-devel/2011-October/015707.html

The conclusion was that userspace drivers (specifically libdrm device
node detection) stopped relying on procfs in 2001. But after some
digging it turned out that the drmstat tool in libdrm is still using
those files (but only when certain options are set). So we've decided
to keep profcs.

But I when I've started to dig around again what exactly this tool
does I've noticed that it tries to read the "mem", "vm", and "vma"
files from procfs. Now as far my git history digging shows "mem" never
did anything useful (at least in the version that first showed up in
upstream history in 2004) and the file was remove in

commit 955b12def42e83287c1bdb1411d99451753c1391
Author: Ben Gamari 
Date:   Tue Feb 17 20:08:49 2009 -0500

    drm: Convert proc files to seq_file and introduce debugfs

Which means that for over 4 years drmstat has been broken, and no one
cared. In my opinion that's proof enough that no one is actually using
drmstat, and so that we can savely nuke the procfs support from drm.

While at it fix up the error case cleanup for debugfs in drm_get_minor.

v2: Fix dates, libdrm stopped relying on procfs for drm node detection
in 2001.

v3: fixup compilation warning for !CONFIG_DEBUG_FS, reported by
Fengguang Wu.

Cc: kbuild test robot 
Cc: Dave Airlie 
Signed-off-by: Daniel Vetter 
Signed-off-by: Dave Airlie

drm: remove the dma_ioctl special-case

2013-08-19T04:15:50+00:00

We might as well have a real ioctl function which checks for the
callbacks. This seems to be a remnant from back in the days when each
drm driver had their own complete ioctl table, with no shared core
drm table at all.

To make really sure no mis-guided user in a kms driver pops up again
explicitly check for that in the new ioctl implementation.

v2: Drop the unused variable I've accidentally left in the code,
spotted by David Herrmann.

Cc: David Herrmann 
Signed-off-by: Daniel Vetter 
Reviewed-by: David Herrmann 
Signed-off-by: Dave Airlie

drm: use ida to allocate connector ids

2013-08-19T00:40:31+00:00

This makes it so that reloading a module does not cause all the
connector ids to change, which are user-visible and sometimes used
for configuration.

Signed-off-by: Ilia Mirkin 
Reviewed-by: Ville Syrjälä 
Signed-off-by: Dave Airlie

drm: mark dma setup/teardown as legacy systems

2013-08-19T00:04:21+00:00

And hide the checks a bit better. This was already disallowed for
modesetting drivers, so no functinal change here.

Reviewed-by: Eric Anholt 
Signed-off-by: Daniel Vetter 
Signed-off-by: Dave Airlie

drm: hide legacy sg cleanup better from common code

2013-08-19T00:03:49+00:00

I've decided that some clear markers for what's legacy dri1/non-gem
code is useful. I've opted to use the drm_legacy prefix and then hide
all the checks in that function for better readability in the common
code.

Reviewed-by: Eric Anholt 
Signed-off-by: Daniel Vetter 
Signed-off-by: Dave Airlie

drm/agp: move AGP cleanup paths to drm_agpsupport.c

2013-08-07T00:14:24+00:00

Introduce two new helpers, drm_agp_clear() and drm_agp_destroy() which
clear all AGP mappings and destroy the AGP head. This allows to reduce the
AGP code in core DRM and move it all to drm_agpsupport.c.

Signed-off-by: David Herrmann 
Signed-off-by: Dave Airlie