handle_unreference only clears up the obj->name and the reference,
but would leave a dangling handle in the idr. The right thing
to do is to call handle_delete.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This is the 2nd attempt, I've always been a bit dissatisified with the
tricky nature of the first one:
http://lists.freedesktop.org/archives/dri-devel/2012-July/025451.html
The issue is that the flink ioctl can race with calling gem_close on
the last gem handle. In that case we'll end up with a zero handle
count, but an flink name (and it's corresponding reference). Which
results in a neat space leak.
In my first attempt I've solved this by rechecking the handle count.
But fundamentally the issue is that ->handle_count isn't your usual
refcount - it can be resurrected from 0 among other things.
For those special beasts atomic_t often suggest way more ordering that
it actually guarantees. To prevent being tricked by those hairy
semantics take the easy way out and simply protect the handle with the
existing dev->object_name_lock.
With that change implemented it's dead easy to fix the flink vs. gem
close reace: When we try to create the name we simply have to check
whether there's still officially a gem handle around and if not refuse
to create the flink name. Since the handle count decrement and flink
name destruction is now also protected by that lock the reace is gone
and we can't ever leak the flink reference again.
Outside of the drm core only the exynos driver looks at the handle
count, and tbh I have no idea why (it's just for debug dmesg output
luckily).
I've considered inlining the drm_gem_object_handle_free, but I plan to
add more name-like things (like the exported dma_buf) to this scheme,
so it's clearer to leave the handle freeing in its own function.
This is exercised by the new gem_flink_race i-g-t testcase, which on
my snb leaks gem objects at a rate of roughly 1k objects/s.
v2: Fix up the error path handling in handle_create and make it more
robust by simply calling object_handle_unreference.
v3: Fix up the handle_unreference logic bug - atomic_dec_and_test
retursn 1 for 0. Oops.
v4: Squash in inlining of drm_gem_object_handle_reference as suggested
by Dave Airlie and add a note that we now have a testcase.
Cc: Dave Airlie <airlied@gmail.com>
Cc: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Daniel writes:
New pile of stuff for -next:
- Cleanup of the old crtc helper callbacks, all encoders are now converted
to the i915 modeset infrastructure.
- Massive amount of wm patches from Ville for ilk, snb, ivb, hsw, this is
prep work to eventually get things going for nuclear pageflips where we
need to adjust watermarks on the fly.
- More vm/vma patches from Ben. This refactoring isn't yet fully rolled
out, we miss the execbuf conversion and some of the low-level
bind/unbind support code.
- Convert our hdmi infoframe code to use the new common helper functions
(Damien). This contains some bugfixes for the common infoframe helpers.
- Some cruft removal from Damien.
- Various smaller bits&pieces all over, as usual.
* tag 'drm-intel-next-2013-08-09' of git://people.freedesktop.org/~danvet/drm-intel: (105 commits)
drm/i915: Fix FB WM for HSW
drm/i915: expose HDMI connectors on port C on BYT
drm/i915: fix a limit check in hsw_compute_wm_results()
drm/i915: unbreak i915_gem_object_ggtt_unbind()
drm/i915: Make intel_set_mode() static
drm/i915: Remove intel_modeset_disable()
drm/i915: Make intel_encoder_dpms() static
drm/i915: Make i915_hangcheck_elapsed() static
drm/i915: Fix #endif comment
drm/i915: Remove i915_gem_object_check_coherency()
drm/i915: Remove stale prototypes
drm/i915: List objects allocated from stolen memory in debugfs
drm/i915: Always call intel_update_sprite_watermarks() when disabling a plane
drm/i915: Pass plane and crtc to intel_update_sprite_watermarks
drm/i915: Don't try to disable plane if it's already disabled
drm/i915: Pass crtc to our update/disable_plane hooks
drm/i915: Split plane watermark parameters into a separate struct
drm/i915: Pull some watermarks state into a separate structure
drm/i915: Calculate max watermark levels for ILK+
drm/i915: Rename hsw_lp_wm_result to intel_wm_level
...
The last user was removed in
commit 575dc34ee0
Author: Dave Airlie <airlied@redhat.com>
Date: Mon Sep 7 18:43:26 2009 +1000
drm/kms: remove old std mode fallback code.
The new code adds modes in the helper, which makes more sense
I disliked the non-driver code adding modes.
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>
This was last used by nouveau, replaced by a driver-specific property
in:
commit de69185573
Author: Ben Skeggs <bskeggs@redhat.com>
Date: Mon Oct 17 12:23:41 2011 +1000
drm/nouveau: improve dithering properties, and implement proper auto mode
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>
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 <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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 955b12def4
Author: Ben Gamari <bgamari@gmail.com>
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 <fengguang.wu@intel.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
It has way too much potential for driver writers to do stupid things
like delayed hw setup because the load sequence is somehow racy (e.g.
the imx driver in staging). So don't call it for modesetting drivers,
which reduces the complexity of the drm core -> driver interface a
notch.
v2: Don't forget to update DocBook.
v3: Go with Laurent's slightly more elaborate proposal for the DocBook
update. Add a few words on top of his diff to elaborate a bit on what
KMS drivers should and shouldn't do in lastclose. There was already a
paragraph present talking about restoring properties, I've simply
extended that one.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
So if we survey kms drivers there's a bunch of things they commonly do
in ->lastclose
- delayed processing of vga switcheroo requests (i915, nouveau,
radeon)
- force-restoring the fbcon (most)
- resetting a bunch properties to make fbcon work better (omap)
- disabling all outputs (vmwgfx)
In short besides the semantically important vga switcheroo stuff they
all try very hard to keep fbcon working in case X dies.
But none of them try to not do this at driver unload time safe for
vmwgfx, and digging through logs I couldn't find any reason for why
vmwgfx is special.
Since ->firstopen has lots of potential for abuse with kms drivers
(like delaying driver setup to pamper over races in the load sequence)
it's imo very much worth it to remove this logic so that we can
stop using the ->firstopen callback for kms drivers.
Also module unloading is rather a debug feature and developers should
know how to restore the display to a sane configuration.
Cc: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Currently, both ranges overlap. Fix the limits so both ranges are mutually
exclusive. Also use the occasion to convert whitespaces to tabs.
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
(fixed up tabs and adjust commit-msg accordingly)
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The idr is protected with our spinlock, if we don't hold that nothing
prevents the gem objects from disappearing from under us.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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 <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The new arch_phys_wc_add/del functions do the right thing both with
and without MTRR support in the kernel. So we can drop these
additional checks.
David Herrmann suggest to also kill the DRIVER_USE_MTRR flag since
it's now unused, which spurred me to do a bit a better audit of the
affected drivers. David helped a lot in that. Quoting our mail
discussion:
On Wed, Jul 10, 2013 at 5:41 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
> On Wed, Jul 10, 2013 at 5:22 PM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> On Wed, Jul 10, 2013 at 3:51 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
>>>> -#if __OS_HAS_MTRR
>>>> -static inline int drm_core_has_MTRR(struct drm_device *dev)
>>>> -{
>>>> - return drm_core_check_feature(dev, DRIVER_USE_MTRR);
>>>> -}
>>>> -#else
>>>> -#define drm_core_has_MTRR(dev) (0)
>>>> -#endif
>>>> -
>>>
>>> That was the last user of DRIVER_USE_MTRR (apart from drivers setting
>>> it in .driver_features). Any reason to keep it around?
>>
>> Yeah, I guess we could rip things out. Which will also force me to
>> properly audit drivers for the eventual behaviour change this could
>> entail (in case there's an x86 driver which did not ask for an mtrr,
>> but iirc there isn't).
>
> david@david-mb ~/dev/kernel/linux $ for i in drivers/gpu/drm/* ; do if
> test -d "$i" ; then if ! grep -q USE_MTRR -r $i ; then echo $i ; fi ;
> fi ; done
> drivers/gpu/drm/exynos
> drivers/gpu/drm/gma500
> drivers/gpu/drm/i2c
> drivers/gpu/drm/nouveau
> drivers/gpu/drm/omapdrm
> drivers/gpu/drm/qxl
> drivers/gpu/drm/rcar-du
> drivers/gpu/drm/shmobile
> drivers/gpu/drm/tilcdc
> drivers/gpu/drm/ttm
> drivers/gpu/drm/udl
> drivers/gpu/drm/vmwgfx
> david@david-mb ~/dev/kernel/linux $
>
> So for x86 gma500,nouveau,qxl,udl,vmwgfx don't set DRIVER_USE_MTRR.
> But I cannot tell whether they break if we call arch_phys_wc_add/del,
> anyway. At least nouveau seemed to work here, but it doesn't use AGP
> or drm_bufs, I guess.
Cool, thanks a lot for stitching together the list of drivers to look
at. So for real KMS drivers it's the drives responsibility to add an
mtrr if it needs one. nouvea, radeon, mgag200, i915 and vmwgfx do that
already. Somehow the savage driver also ends up doing that, I have no
idea why.
Note that gma500 as a pure KMS driver doesn't need MTRR setup since
the platforms that it supports all support PAT. So no MTRRs needed to
get wc iomappings.
The mtrr support in the drm core is all for legacy mappings of garts,
framebuffers and registers. All legacy drivers set the USE_MTRR flag,
so we're good there.
All in all I think we can really just ditch this
/endquote
v2: Also kill DRIVER_USE_MTRR as suggested by David Herrmann
v3: Rebase on top of David Herrmann's agp setup/cleanup changes.
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Trying to drop a reference we don't have is a pretty serious bug.
Trying to paper over it is an even worse offense.
So scream into dmesg with a big WARN in case that ever happens.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Calling this function with a NULL object is simply a bug, so papering
over a NULL object not a good idea.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
We have three callers of this function now and it's neither
performance critical nor really small. So an inline function feels
like overkill and unecessarily separates the different parts of the
code.
Since all callers of drm_gem_object_handle_free are now in drm_gem.c
we can make that static (and remove the unused EXPORT_SYMBOL). To
avoid a forward declaration move it (and drm_gem_object_free_bug) up a
bit.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
I've checked both implementations (radeon/nouveau) and they both grab
the page array from ttm simply by dereferencing it and then wrapping
it up with drm_prime_pages_to_sg in the callback and map it with
dma_map_sg (in the helper).
Only the grabbing of the underlying page array is anything we need to
be concerned about, and either those pages are pinned independently,
or we're screwed no matter what.
And indeed, nouveau/radeon pin the backing storage in their
attach/detach functions.
Since I've created this patch cma prime support for dma_buf was added.
drm_gem_cma_prime_get_sg_table only calls kzalloc and the creates&maps
the sg table with dma_get_sgtable. It doesn't touch any gem object
state otherwise. So the cma helpers also look safe.
The only thing we might claim it does is prevent concurrent mapping of
dma_buf attachments. But a) that's not allowed and b) the current code
is racy already since it checks whether the sg mapping exists _before_
grabbing the lock.
So the dev->struct_mutex locking here does absolutely nothing useful,
but only distracts. Remove it.
This should also help Maarten's work to eventually pin the backing
storage more dynamically by preventing locking inversions around
dev->struct_mutex.
v2: Add analysis for recently added cma helper prime code.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Note that this is slightly tricky since both drivers store their
native objects in dma_buf->priv. But both also embed the base
drm_gem_object at the first position, so the implicit cast is ok.
To use the release helper we need to export it, too.
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
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 <imirkin@alum.mit.edu>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Daniel Vetter
Dave Airlie
Lespiau, Damien
Kristian Høgsberg
Inki Dae
David Herrmann
Ilia Mirkin
Rob Clark