Commit Graph

16 Commits

Author SHA1 Message Date
David Herrmann
099d1c290e drm: provide device-refcount
Lets not trick ourselves into thinking "drm_device" objects are not
ref-counted. That's just utterly stupid. We manage "drm_minor" objects on
each drm-device and each minor can have an unlimited number of open
handles. Each of these handles has the drm_minor (and thus the drm_device)
as private-data in the file-handle. Therefore, we may not destroy
"drm_device" until all these handles are closed.

It is *not* possible to reset all these pointers atomically and restrict
access to them, and this is *not* how this is done! Instead, we use
ref-counts to make sure the object is valid and not freed.

Note that we currently use "dev->open_count" for that, which is *exactly*
the same as a reference-count, just open coded. So this patch doesn't
change any semantics on DRM devices (well, this patch just introduces the
ref-count, anyway. Follow-up patches will replace open_count by it).

Also note that generic VFS revoke support could allow us to drop this
ref-count again. We could then just synchronously disable any fops->xy()
calls. However, this is not the case, yet, and no such patches are
in sight (and I seriously question the idea of dropping the ref-cnt
again).

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
2014-03-16 12:25:17 +01:00
Daniel Vetter
b3f2333de8 drm: restrict the device list for shadow attached drivers
There's really no need for the drm core to keep a list of all
devices of a given driver - the linux device model keeps perfect
track of this already for us.

The exception is old legacy ums drivers using pci shadow attaching.
So rename the lists to make the use case clearer and rip out everything
else.

v2: Rebase on top of David Herrmann's drm device register changes.
Also drop the bogus dev_set_drvdata for platform drivers that somehow
crept into the original version - drivers really should be in full
control of that field.

v3: Initialize driver->legacy_dev_list outside of the loop, spotted by
David Herrmann.

v4: Rebase on top of the newly created host1x drm_bus for tegra.

Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-12-18 11:08:36 +10:00
Daniel Vetter
e2577d455a drm: rip out drm_platform_exit
This very much looks like a remnant of the old legady ums shadow
attach days. Now with the last users gone we can rip it out since
we won't ever support an ums drm driver again.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-12-18 11:06:22 +10:00
David Herrmann
0dc8fe5985 drm: introduce drm_dev_free() to fix error paths
The error paths in DRM bus drivers currently leak memory as they don't
correctly revert drm_dev_alloc(). Introduce drm_dev_free() to free DRM
devices which haven't been registered, yet.

We must be careful not to introduce any side-effects with cleanups done in
drm_dev_free(). drm_ht_remove(), drm_ctxbitmap_cleanup() and
drm_gem_destroy() are all fine in that regard.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-10-09 15:55:09 +10:00
David Herrmann
c22f0ace19 drm: merge device setup into drm_dev_register()
All bus drivers do device setup themselves. This requires us to adjust all
of them if we introduce new core features. Thus, merge all these into a
uniform drm_dev_register() helper.

Note that this removes the drm_lastclose() error path for AGP as it is
horribly broken. Moreover, no bus driver called this in any other error
path either. Instead, we use the recently introduced AGP cleanup helpers.

We also keep a DRIVER_MODESET condition around pci_set_drvdata() to keep
semantics.

[airlied: keep passing flags through so drivers don't oops on load]

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-10-09 15:54:31 +10:00
David Herrmann
1bb72532ac drm: add drm_dev_alloc() helper
Instead of managing device allocation+initialization in each bus-driver,
we should do that in a central place. drm_fill_in_dev() already does most
of it, but also requires the global drm lock for partial AGP device
registration.

Split both apart so we have a clean device initialization/allocation
phase, and a registration phase.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-10-09 14:38:15 +10:00
David Herrmann
1793126fce drm: implement experimental render nodes
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 <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-08-30 08:43:57 +10:00
Lespiau, Damien
66cc8b6b8b drm: Make drm_get_platform_dev() static
It's only used in drm_platform.c.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-08-21 12:47:56 +10:00
Thierry Reding
a16d4f8601 drm: platform: Don't initialize driver-private data
Platform device drivers usually use the driver-private data for their
own purposes. Having it overwritten by drm_platform_init() is confusing
and error-prone.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-10-23 10:15:11 +10:00
David Howells
760285e7e7 UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/
Convert #include "..." to #include <path/...> in drivers/gpu/.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-02 18:01:07 +01:00
Rob Clark
b19c19afa8 drm: cope with platformdev->id == -1
If there are not multiple instances of a platform device, the id
should apparently be set to -1.  Which results in a odd looking
bus-id like "platform:foodrm:-1".  Probably we should just treat
this case as id 0.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-07 14:03:40 +00:00
Paul Gortmaker
2d1a8a48ac gpu: Add export.h as required to drivers/gpu files.
They need this to get all the EXPORT_SYMBOL variants and THIS_MODULE

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:03 -04:00
Rob Clark
28a4a163b5 drm: platform multi-device support
Include the device id in the bus-id to give userspace a way to open
the correct "cardN" when there are multiple device instances.

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-07-15 06:52:58 +01:00
Dave Airlie
8410ea3b95 drm: rework PCI/platform driver interface.
This abstracts the pci/platform interface out a step further,
we can go further but this is far enough for now to allow USB
to be plugged in.

The drivers now just call the init code directly for their
device type.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-02-07 13:09:36 +10:00
Dave Airlie
b64c115eb2 drm: fix race between driver loading and userspace open.
Not 100% sure this is due to BKL removal, its most likely a combination
of that + userspace timing changes in udev/plymouth. The drm adds the sysfs
device before the driver has completed internal loading, this causes udev
to make the node and plymouth to open it before we've completed loading.

The proper solution is to delay the sysfs manipulation until later in loading
however this causes knock on issues with sysfs connector nodes, so we can use
the global mutex to serialise loading and userspace opens.

Reported-by: Toni Spets (hifi on #radeon)
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-09-14 20:39:04 +10:00
Jordan Crouse
dcdb167402 drm: Add support for platform devices to register as DRM devices
Allow platform devices without PCI resources to be DRM devices.

[airlied: fixup warnings with dev pointers]

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-06-01 10:07:39 +10:00