DRM_IOCTL_MODE_GETFB is used to retrieve information about a given
framebuffer ID. It is a read-only helper and was thus declassified for
unprivileged access in:
commit a14b1b4247
Author: Mandeep Singh Baines <mandeep.baines@gmail.com>
Date: Fri Jan 20 12:11:16 2012 -0800
drm: remove master fd restriction on mode setting getters
However, alongside width, height and stride information,
DRM_IOCTL_MODE_GETFB also passes back a handle to the underlying buffer of
the framebuffer. This handle allows users to mmap() it and read or write
into it. Obviously, this should be restricted to DRM-Master.
With the current setup, *any* process with access to /dev/dri/card0 (which
means any process with access to hardware-accelerated rendering) can
access the current screen framebuffer and modify it ad libitum.
For backwards-compatibility reasons we want to keep the
DRM_IOCTL_MODE_GETFB call unprivileged. Besides, it provides quite useful
information regarding screen setup. So we simply test whether the caller
is the current DRM-Master and if not, we return 0 as handle, which is
always invalid. A following DRM_IOCTL_GEM_CLOSE on this handle will fail
with EINVAL, but we accept this. Users shouldn't test for errors during
GEM_CLOSE, anyway. And it is still better as a failing MODE_GETFB call.
v2: add capable(CAP_SYS_ADMIN) check for compatibility with i-g-t
Cc: <stable@vger.kernel.org>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch adds the notion of a drm_bridge. A bridge is a chained
device which hangs off an encoder. The drm driver using the bridge
should provide the association between encoder and bridge. Once a
bridge is associated with an encoder, it will participate in mode
set, and dpms (via the enable/disable hooks).
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Let applications know whether the kernel supports asynchronous page
flipping.
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
This lets drivers see the flags requested by the application
[airlied: fixup for rcar/imx/msm]
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
It's only used in drm_crtc.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>
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>
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>
So it looks like for virtual hw cursors on QXL we need to inform
the "hw" device what the cursor hotspot parameters are. This
makes sense if you think the host has to draw the cursor and interpret
clicks from it. However the current modesetting interface doesn't support
passing the hotspot information from userspace.
This implements a new cursor ioctl, that takes the hotspot info as well,
userspace can try calling the new interface and if it gets -ENOSYS it means
its on an older kernel and can just fallback.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Drivers are allowed (actually have to) disable unrelated crtcs in
their ->set_config callback (when we steal all the connectors from
that crtc). If they do that they'll clear crtc->fb to NULL.
Which results in a refcount leak, since the drm core is keeping track
of that reference.
To fix this track the old fb of all crtcs and adjust references for
all of them. Of course, since we only hold an additional reference for
the fb for the current crtc we need to increase refcounts before we
drop the old one.
This approach has the benefit that it inches us a bit closer to an
atomic modeset world, where we want to update the config of all crtcs
in one step.
This regression has been introduce in the framebuffer refcount
conversion, specifically in
commit b0d1232589
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Dec 11 01:07:12 2012 +0100
drm: refcounting for crtc framebuffers
Reported-by: Russell King <linux@arm.linux.org.uk>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Historically drm lacked fb refcounting, so the updating of crtc->fb
was done by the lower levels at a point convenient to get their own
refcounting (e.g. refcounts for the underlying gem bo, pinning
refcounts) right. With the introduction of refcounted fbs the drm core
handled the fb refcounts, but still relied on drivers to update the
crtc->fb pointer (this approach required the least invasive changes in
drivers).
Enforce this contract with a WARN_ON.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
There's a bunch of unused members inside drm_plane, bloating the size of
the structure needlessly. Eliminate them.
v2: Remove all of it from kernel-doc too
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
v2: Follow the drm_crtc documentation fixes
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
drm_plane_force_disable() will forcibly disable the plane even if user
had previously requested the plane to be enabled.
This can be used to force planes to be off when restoring the fbdev
mode.
The code was simply pulled from drm_framebuffer_remove(), which now
calls the new function as well.
v2: Check plane->fb in drm_plane_force_disable(), drop bogus comment
about disabling crtc
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Keeping the modes in the same order as we probe them makes it a bit
easier to track what's happening.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The structures and strings involved with various pretty-print functions
aren't meant to be modified, so make them all const. The exception is
drm_connector_enum_list which does get modified in drm_connector_init().
While at it move the drm_get_connector_status_name() prototype from
drmP.h to drm_crtc.h where it belongs.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Rather than just printing the pixel format as a hex number, decode the
fourcc into human readable form, and also decode the LE vs. BE flag.
Keep printing the raw hex number too in case it contains non-printable
characters.
Some examples what the new drm_get_format_name() produces:
DRM_FORMAT_XRGB8888: "XR24 little-endian (0x34325258)"
DRM_FORMAT_YUYV: "YUYV little-endian (0x56595559)"
DRM_FORMAT_RGB565|DRM_FORMAT_BIG_ENDIAN: "RG16 big-endian (0xb6314752)"
Unprintable characters: "D??? big-endian (0xff7f0244)"
v2: Fix patch author
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Instead of just printing "status updated from 1 to 2", make those enum
numbers immediately readable.
v2: Also patch output_poll_execute() (Daniel Vetter)
v3: Use drm_get_connector_status_name (Ville Syrjälä)
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> (for v1)
Signed-off-by: Dave Airlie <airlied@redhat.com>
Daniel writes:
A few intel fixes for smaller issues and one revert for an sdv hack which
we've wanted to kill anyway. Plus two drm patches included for your
convenience, both regression fixers for mine own screw-ups.
+ both fixes for stolen mem handling.
* 'for-linux-next' of git://people.freedesktop.org/~danvet/drm-intel:
drm/i915: clear the stolen fb before resuming
Revert "drm/i915: Calculate correct stolen size for GEN7+"
drm/i915: hsw: fix link training for eDP on port-A
Revert "drm/i915: revert eDP bpp clamping code changes"
drm: don't check modeset locks in panic handler
drm/i915: Fix pipe enabled mask for pipe C in WM calculations
drm/mm: fix dump table BUG
drm/i915: Always normalize return timeout for wait_timeout_ioctl
Since we know that locking is broken in that case and it's more
important to not flood the dmesg with random gunk.
Cc: Dave Airlie <airlied@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
References: http://lkml.kernel.org/r/20130502000206.GH15623@pd.tnic
Cc: stable@vger.kernel.org
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
There is no way to use modes added to the user_modes list. We never
look at the contents of said list in the kernel, and the only operations
userspace can do are attach and detach. So the only "benefit" of this
interface is wasting kernel memory.
Fortunately it seems no real user space application ever used these
ioctls. So just kill them.
Also remove the prototypes for the non-existing drm_mode_addmode_ioctl()
and drm_mode_rmmode_ioctl() functions.
v2: Use drm_noop instead of completely removing the ioctls
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_pci.c:155:5: warning: symbol 'drm_pci_set_busid' was not declared. Should it be static?
drivers/gpu/drm/drm_pci.c:197:5: warning: symbol 'drm_pci_set_unique' was not declared. Should it be static?
drivers/gpu/drm/drm_pci.c:269:5: warning: symbol 'drm_pci_agp_init' was not declared. Should it be static?
drivers/gpu/drm/drm_crtc.c:181:1: warning: symbol 'drm_get_dirty_info_name' was not declared. Should it be static?
drivers/gpu/drm/drm_crtc.c:1123:5: warning: symbol 'drm_mode_group_init' was not declared. Should it be static?
drivers/gpu/drm/drm_modes.c:918:6: warning: symbol 'drm_mode_validate_clocks' was not declared. Should it be static?
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
A page flip is not a mode set, changing the frame buffer pixel format
doesn't make sense and isn't handled by most drivers anyway. Disallow
it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Property blob objects need to be destroyed when cleaning up to avoid
memory leaks. Go through the list of all blobs in the
drm_mode_config_cleanup() function and destroy them.
The drm_mode_config_cleanup() function needs to be moved after the
drm_property_destroy_blob() declaration. Move drm_mode_config_init() as
well to keep the functions together.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drm_framebuffer_lookup() does a kref_get() for the framebuffer if it finds one
corresponding to the fb id passed to it. Use drm_framebuffer_reference() instead
for clarity since it's the function used in other places to take a reference.
Signed-off-by: Archit Taneja <archit@ti.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
We don't grab the modeset locks any more since
commit 468174f748
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Dec 11 00:09:12 2012 +0100
drm: push modeset_lock_all into ->fb_create driver callbacks
Reported-by: Ray Strode <rstrode@redhat.com>
Cc: Ray Strode <rstrode@redhat.com>
Cc: Dave Airlie <airlied@gmail.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated. Drop its usage.
* drm_ctxbitmap_cleanup() was calling idr_remove_all() but forgetting
idr_destroy() thus leaking all buffered free idr_layers. Replace it
with idr_destroy().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David Airlie <airlied@linux.ie>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Driver implementations of the drm_crtc's .page_flip() function are
required to update the crtc->fb field on success to reflect that the new
framebuffer is now in use. This is important to keep reference counting
on the framebuffers balanced.
While at it, document this requirement to keep others from falling into
the same trap.
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
So here's my promised pile of fixes for 3.9. I've dropped the core prep
patches for vt-switchless suspend/resume as discussed on irc. Highlights:
- Fix dmar on g4x. Not really gfx related, but I'm fed up with getting
blamed for dmar crapouts.
- Disable wc ptes updates on ilk when dmar is enabled (Chris). So again,
dmar, but this time gfx related :(
- Reduced range support for hsw, using the pipe CSC (Ville).
- Fixup pll limits for gen3/4 (Patrick Jakobsson). The sdvo patch is
already confirmed to fix 2 bug reports, so added cc: stable on that one.
- Regression fix for 8bit fb console (Ville).
- Preserve lane reversal bits on DDI/FDI ports (Damien).
- Page flip vs. gpu hang fixes (Ville). Unfortuntely not quite all of
them, need to decide what to do with the currently still in-flight ones.
- Panel fitter regression fix from Mika Kuoppala (was accidentally left on
on some pipes with the new modset code since 3.7). This also improves
the modeset sequence and might help a few other unrelated issues with
lvds.
- Write backlight regs even harder ... another installement in our eternal
fight against the BIOS and backlights.
- Fixup lid notifier vs. suspend/resume races (Zhang Rui). Prep work for
new ACPI stuff, but closing the race itself seems worthwile on its own.
- A few other small fixes and tiny cleanups all over.
Lots of the patches are cc: stable since I've stalled on a few
not-so-important fixes for 3.8 due to the grumpy noise Linus made.
* 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel: (33 commits)
intel/iommu: force writebuffer-flush quirk on Gen 4 Chipsets
drm/i915: Disable WC PTE updates to w/a buggy IOMMU on ILK
drm/i915: Implement pipe CSC based limited range RGB output
drm/i915: inverted brightness quirk for Acer Aspire 4736Z
drm/i915: Print the hw context status is debugfs
drm/i915: Use HAS_L3_GPU_CACHE in i915_gem_l3_remap
drm/i915: Fix PIPE_CONTROL DW/QW write through global GTT on IVB+
drm/i915: Set i9xx sdvo clock limits according to specifications
drm/i915: Set i9xx lvds clock limits according to specifications
drm/i915: Preserve the DDI link reversal configuration
drm/i915: Preserve the FDI line reversal override bit on CPT
drm/i915: add missing \n to UTS_RELEASE in the error_state
drm: Use C8 instead of RGB332 when determining the format from depth/bpp
drm: Fill depth/bits_per_pixel for C8 format
drm/i915: don't clflush gem objects in stolen memory
drm/i915: Don't wait for page flips if there was GPU reset
drm/i915: Kill obj->pending_flip
drm/i915: Fix a typo in a intel_modeset_stage_output_state() comment
drm/i915: remove bogus mutex_unlock from error-path
drm/i915: Print the pipe control page GTT address
...
Support for real RGB332 is a rarity, most hardware only really support
C8. So use C8 instead of RGB332 when determining the format based on
depth/bpp.
This fixes 8bpp fbcon on i915, since i915 will only accept C8 and not
RGB332.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59572
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Tested-by: mlsemon35@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Set depth/bits_per_pixel to 8 for C8 format.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We need to clear the local variable to get the refcounting right
(since the reference drm_mode_setplane holds is transferred to the
plane->fb pointer). But should be done _after_ we update the pointer.
Breakage introduced in
commit 6c2a75325c
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue Dec 11 00:59:24 2012 +0100
drm: refcounting for sprite framebuffers
Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Rob Clark <rob@ti.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
... it's required. Fix up exynos and the cma helper, and add a
corresponding WARN_ON to drm_fb_helper_restore_fbdev_mode.
Note that tegra calls the fbdev cma helper restore function also from
it's driver-load callback. Which is a bit against current practice,
since usually the call is only from ->lastclose, and initial setup is
done by drm_fb_helper_initial_config.
Also add the relevant drm DocBook entry.
v2: Add promised WARN to restore_fbdev_mode.
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The coup de grace of the entire journey. No more dropped frames every
10s on my testbox!
I've tried to audit all ->detect and ->get_modes callbacks, but things
became a bit fuzzy after trying to piece together the umpteenth
implemenation. Afaict most drivers just have bog-standard output
register frobbing with a notch of i2c edid reading, nothing which
could potentially race with the newly concurrent pageflip/set_cursor
code. The big exception is load-detection code which requires a
running pipe, but radeon/nouveau seem to to this without touching any
state which can be observed from page_flip (e.g. disabled crtcs
temporarily getting enabled and so a pageflip succeeding).
The only special case I could find is the i915 load detect code. That
uses the normal modeset interface to enable the load-detect crtc, and
so userspace could try to squeeze in a pageflip on the load-detect
pipe. So we need to grab the relevant crtc mutex in there, to avoid
the temporary crtc enabling to sneak out and be visible to userspace.
Note that the sysfs files already stopped grabbing the per-crtc locks,
since I didn't want to bother with doing a interruptible
modeset_lock_all. But since there's very little in-between breakage
(essentially just the ability for userspace to pageflip on load-detect
crtcs when it shouldn't on the i915 driver) I figured I don't need to
bother.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The pagelip ioctl itself is rather simply, so the hard work for this
patch is auditing all the drivers:
- exynos: Pageflip is protect with dev->struct_mutex and ...
synchronous. But nothing fancy going on, besides a check whether the
crtc is enabled, which should probably be somewhere in the drm core
so that we have unified behaviour across all drivers.
- i915: hw-state is protected with dev->struct_mutex, the delayed
unpin work together with the other stuff the pageflip complete irq
handler needs is protected by the event_lock spinlock.
- nouveau: With the pin/unpin functions fixed, everything looks safe:
A bit of ttm wrestling and refcounting, and a few channel accesses.
The later are either already proteced sufficiently, or are now safe
with the channel locking introduced to make cursor updates safe.
- radeon: The irq_get/put functions look a bit race, since the
atomic_inc/dec isn't protect with locks. Otoh they're all per-crtc,
so we should be safe with per-crtc locking from the drm core. Then
there's tons of per-crtc register access, which could potentially go
through the indirect reg acces. But that's fixed to make cursor
updates concurrent. Bookeeping for the drm even is also protected
with the even_lock, which also protects against the pageflip irq
handler since radeon hw seems to have no way to queue these up
asynchronously. Otherwise just a bit of ttm-based buffer handling
and fencing, which is now safe with the previous patch to hold
bdev->fence_lock while grabbing the ttm fence.
- shmob: Only one crtc. That's an easy one ...
- vmwgfx: As usual a bit special with tons different things:
- Flippable check using is_implicit and num_implicit. Changes to
those seem to be nicely covered with the global modeset lock, so
we should be fine.
- Some dirty cliprect handling stuff, or at least that is my guess.
Looks like it's fine since either it's per-crtc, invariant or
(like the execbuf stuff launched) protected otherwise.
- Adding the actual flip to the fence_event list. On a quick look
this seems to have solid locking in place, too.
... but generally this is all way over my head.
- imx: Impressive display of races between the page_flip
implementation and the irq handler. Also, ipu_drm_set_base which
gets eventually called from the irq handler to update the display
base isn't really protected against concurrent set_config calls from
process context. In any case, going for per-crtc locking won't make
this worse, so nothing to do.
- omap: The new async callback code merged into 3.8 seems to have
solid locking in place, and there doesn't seem to be any shared
state at risk. Especially since the callbacks still use
modeset_lock_all and are so not converted.
v2: Update omapdrm analysis to 3.8 code per the discussion with Rob
Clark.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now that all framebuffer usage is properly refcounted, we are no
longer required to hold the modeset locks while dropping the last
reference. Hence implemented a fastpath which avoids the potential
stalls associated with grabbing mode_config.lock for the case where
there's no other reference around.
Explain in a big comment why it is safe. Also update kerneldocs with
the new locking rules around drm_framebuffer_remove.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
With the prep patch to encapsulate ->set_crtc calls, this is now
rather easy. Hooray for inconsistent semantics between ->set_crtc and
->page_flip, where the driver callback is supposed to update the fb
pointer, and ->update_plane, where the drm core does the same.
Also, since the drm core functions check crtc->fb before calling into
driver callbacks, we can't really reduce the critical sections
protected by the mode_config locks.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Now plane->fb holds a reference onto it's framebuffer. Nothing too
fancy going on here:
- Extract __drm_framebuffer_unreference to be called when we know
we're not dropping the last reference, e.g. useful in the fb cleanup
code.
- Reduce the locked sections in the set_plane ioctl to only protect
plane->fb/plane->crtc and the driver callback (i.e. hw state).
Everything either doesn't disappear (crtc, plane) or is refcounted
(fb), and all the data we check is invariant over the respective
object's lifetimes.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We only need to ensure that the fb stays around for long enough. While
at it, only grab the modeset locks when we need them (since most
drivers don't implement the dirty callback, this should help jitter
and stalls when using the generic modeset driver).
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We only need to push the fb unreference a bit down. While at it,
properly pass the return value from ->create_handle back to userspace.
Most drivers either return -ENODEV if they don't have a concept of
buffer objects (ast, cirrus, ...) or just install a handle for the
underlying gem object (which is ok since we hold a reference on that
through the framebuffer).
v2: Split out the ->create_handle rework in the individual drivers.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
And drop it where it's not needed. Most driver just lookup the gem
object, allocate an fb struct, fill in all the useful fields and then
register it with drm_framebuffer_init.
All of these operations are already separately locked, and since we
only put the fb into the fpriv->fbs list _after_ having called
->fb_create, we can't also race with rmfb. We can otoh race with other
ioctls that put the framebuffer to use, but all drivers have been
reorganized already to call drm_framebuffer_init last in the fb
creation sequence.
So essentially, we can completely remove any modeset locks from the
addfb ioctl paths. Yeah!
Also, reference-counting is solid - we get a reference from fb_create
which we transfer to the fpriv->fbs list. And after unlocking the
fpriv->fbs_lock we don't touch the framebuffer any longer. Furthermore
drm_framebuffer_init has added a 2nd reference for the idr lookup, and
any access through that table will do it's own refcounting.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Atm we still need to unconditionally take the modeset locks in the
rmfb paths. But eventually we only want to take them if there are
other users around as a slow-path. This way sane userspace avoids
blocking on edid reads and other stuff in rmfb if it ensures that the
fb isn't used anywhere by a crtc/plane.
We can do a quick check for such other users once framebuffers are
properly refcounting by locking at the refcount - if it's more than 1,
there are other users left. Again, rmfb racing against other ioctls
isn't a real problem, userspace is allowed to shoot its foot.
This patch just prepares this by moving the modeset locks to nest
within fpriv->fbs_lock. Now the distinction between the fbs_lock and
the device-global fb_lock is clear, since we need to hold the fbs_lock
outside of any modeset_locks in fb_release.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Since otherwise looking and reference-counting around
drm_framebuffer_lookup will be an unmanageable mess. With this change,
an object can either be found in the idr and will stay around once we
incremented the reference counter. Or it will be gone for good and
can't be looked up using its id any more.
Atomicity is guaranteed by the dev->mode_config.fb_lock. The
newly-introduce fpriv->fbs_lock looks a bit redundant, but the next
patch will shuffle the locking order between these two locks and all
the modeset locks taken in modeset_lock_all, so we'll need it.
Also, since userspace could do really funky stuff and race e.g. a
getresources with an rmfb, we need to make sure that the kernel
doesn't fall over trying to look-up an inexistent fb, or causing
confusion by having two fbs around with the same id. Simply reset the
framebuffer id to 0, which marks it as reaped. Any lookups of that id
will fail, so the object is really gone for good from userspace's pov.
Note that we still need to protect the "remove framebuffer from all
use-cases" and the final unreference with the modeset-lock, since most
framebuffer use-sites don't implement proper reference counting yet.
We can only lift this once _all_ users are converted.
With this change, two references are held on alife, but unused
framebuffers:
- The reference for the idr lookup, created in this patch.
- For user-created framebuffers the fpriv->fbs reference, for
driver-private fbs the driver is supposed to hold it's own last
reference.
Note that the dev->mode_config.fb_list itself does _not_ hold a
reference onto the framebuffers (this list is essentially only used
for debugfs files). Hence if there's anything left there when the
driver has cleaned up all it's modeset resources, this is a ref-leak.
WARN about it.
Now we only need to fix up all other places to properly reference
count framebuffers.
v2: Fix spelling fail in a comment spotted by Rob Clark.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We have two classes of framebuffer
- Created by the driver (atm only for fbdev), and the driver holds
onto the last reference count until destruction.
- Created by userspace and associated with a given fd. These
framebuffers will be reaped when their assoiciated fb is closed.
Now these two cases are set up differently, the framebuffers are on
different lists and hence destruction needs to clean up different
things. Also, for userspace framebuffers we remove them from any
current usage, whereas for internal framebuffers it is assumed that
the driver has done this already.
Long story short, we need two different ways to cleanup such drivers.
Three functions are involved in total:
- drm_framebuffer_remove: Convenience function which removes the fb
from all active usage and then drops the passed-in reference.
- drm_framebuffer_unregister_private: Will remove driver-private
framebuffers from relevant lists and drop the corresponding
references. Should be called for driver-private framebuffers before
dropping the last reference (or like for a lot of the drivers where
the fbdev is embedded someplace else, before doing the cleanup
manually).
- drm_framebuffer_cleanup: Final cleanup for both classes of fbs,
should be called by the driver's ->destroy callback once the last
reference is gone.
This patch just rolls out the new interfaces and updates all drivers
(by adding calls to drm_framebuffer_unregister_private at all the
right places)- no functional changes yet. Follow-on patches will move
drm core code around and update the lifetime management for
framebuffers, so that we are no longer required to keep framebuffers
alive by locking mode_config.mutex.
I've also updated the kerneldoc already.
vmwgfx seems to again be a bit special, at least I haven't figured out
how the fbdev support in that driver works. It smells like it's
external though.
v2: The i915 driver creates another private framebuffer in the
load-detect code. Adjust its cleanup code, too.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
And replace all fb lookups with it. Also add a WARN to
drm_mode_object_find since that is now no longer the blessed interface
to look up an fb. And add kerneldoc to both functions.
This only updates all callsites, but immediately drops the acquired
refence again. Hence all callers still rely on the fact that a mode fb
can't disappear while they're holding the struct mutex. Subsequent
patches will instate proper use of refcounts, and then rework the rmfb
and unref code to no longer serialize fb destruction with the
mode_config lock. We don't want that since otherwise a compositor
might end up stalling for a few frames in rmfb.
v2: Don't use kref_get_unless_zero - Greg KH doesn't like that kind of
interface.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Well, at least step 1. The goal here is that framebuffer objects can
survive outside of the mode_config lock, with just a reference held
as protection. The first step to get there is to introduce a special
fb_lock which protects fb lookup, creation and destruction, to make
them appear atomic.
This new fb_lock can nest within the mode_config lock. But the idea is
(once the reference counting part is completed) that we only quickly
take that fb_lock to lookup a framebuffer and grab a reference,
without any other locks involved.
vmwgfx is the only driver which does framebuffer lookups itself, also
wrap those calls to drm_mode_object_find with the new lock.
Also protect the fb_list walking in i915 and omapdrm with the new lock.
As a slight complication there's also the list of user-created fbs
attached to the file private. The problem now is that at fclose() time
we need to walk that list, eventually do a modeset call to remove the
fb from active usage (and are required to be able to take the
mode_config lock), but in the end we need to grab the new fb_lock to
remove the fb from the list. The easiest solution is to add another
mutex to protect this per-file list.
Currently that new fbs_lock nests within the modeset locks and so
appears redudant. But later patches will switch around this sequence
so that taking the modeset locks in the fb destruction path is
optional in the fastpath. Ultimately the goal is that addfb and rmfb
do not require the mode_config lock, since otherwise they have the
potential to introduce stalls in the pageflip sequence of a compositor
(if the compositor e.g. switches to a fullscreen client or if it
enables a plane). But that requires a few more steps and hoops to jump
through.
Note that framebuffer creation/destruction is now double-protected -
once by the fb_lock and in parts by the idr_lock. The later would be
unnecessariy if framebuffers would have their own idr allocator. But
that's material for another patch (series).
v2: Properly initialize the fb->filp_head list in _init, otherwise the
newly added WARN to check whether the fb isn't on a fpriv list any
more will fail for driver-private objects.
v3: Fixup two error-case unlock bugs spotted by Richard Wilbur.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
->cursor_move uses mostly the same facilities in drivers as
->cursor_set, so pretty much nothing to fix up:
- ast/gma500/i915: They all use per-crtc registers to update the
cursor position. ast again touches the global cursor cache, but
that's ok since there's only one crtc.
- nouveau: nv50+ is again special, updates happen through the per-crtc
channel (without pushbufs), so it's not protected by the new evo
lock introduced earlier. But since this channel is per-crtc, we
should be fine anyway.
- radeon: A bit a mess: avivo asics need a workaround when both output
pipes are enabled, which means it'll access the crtc list. Just
reading that flag is ok though as long as radeon _always_ grabs all
locks when changing the crtc configuration. Which means with the
current scheme it cannot do an optimized modeset which only locks
the relevant crtcs. This can be fixed though by introducing a bit of
global state with separate locks and ensure in the modeset code that
the cursor will be updated appropriately when enabling the 2nd pipe
(on affected asics).
- vmwgfx: I still don't understand what it's doing exactly, so apply
the same trick for now.
v2: Fixup unlocking for the error cases, spotted by Richard Wilbur.
v3: Another error-case fixup.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
First convert ->cursor_set to only take the crtc lock, since that
seems to be the function with the least amount of state - the core
ioctl function doesn't check anything which can change at runtime, so
we don't have any object lifetime issues to contend.
The only thing which is important is that the driver's implementation
doesn't touch any state outside of that single crtc which is not yet
properly protected by other locking:
- ast: access the global ast->cache_kmap. Luckily we only have on crtc
on this driver, so this is fine. Add a comment.
- gma500: calls gma_power_begin|and and psb_gtt_pin|unpin, both which
have their own locking to protect their state. Everything else is
crtc-local.
- i915: touches a bit of global gem state, all protected by the One
Lock to Rule Them All (dev->struct_mutex).
- nouveau: Pre-nv50 is all nice, nv50+ uses the evo channels to queue
up all display changes. And some of these channels are device
global. But this is fine now since the previous patch introduced an
evo channel mutex.
- radeon: Uses some indirect register access for cursor updates, but
with the previous patches to protect these indirect 2-register
access patterns with a spinlock, this should be fine now, too.
- vmwgfx: I have no idea how that works - update_cursor_position
doesn't take any per-crtc argument and I haven't figured out any
other place where this could be set in some form of a side-channel.
But vmwgfx definitely has more than one crtc (or at least can
register more than one), so I have no idea how this is supposed to
not fail with the current code already. Hence take the easy way out
and simply acquire all locks (which requires dropping the crtc lock
the core acquired for us). That way it's not worse off for
consistency than the old code.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
*drumroll*
The basic idea is to protect per-crtc state which can change without
touching the output configuration with separate mutexes, i.e. all the
input side state to a crtc like framebuffers, cursor settings or plane
configuration. Holding such a crtc lock gives a read-lock on all the
other crtc state which can be changed by e.g. a modeset.
All non-crtc state is still protected by the mode_config mutex.
Callers that need to change modeset state of a crtc (e.g. dpms or
set_mode) need to grab both the mode_config lock and nested within any
crtc locks.
Note that since there can only ever be one holder of the mode_config
lock we can grab the subordinate crtc locks in any order (if we need
to grab more than one of them). Lockdep can handle such nesting with
the mutex_lock_nest_lock call correctly.
With this functions that only touch connectors/encoders but not crtcs
only need to take the mode_config lock. The biggest such case is the
output probing, which means that we can now pageflip and move cursors
while the output probe code is reading an edid.
Most cases neatly fall into the three buckets:
- Only touches connectors and similar output state and so only needs
the mode_config lock.
- Touches the global configuration and so needs all locks.
- Only touches the crtc input side and so only needs the crtc lock.
But a few cases that need special consideration:
- Load detection which requires a crtc. The mode_config lock already
prevents a modeset change, so we can use any unused crtc as we like
to do load detection. The only thing to consider is that such
temporary state changes don't leak out to userspace through ioctls
that only take the crtc look (like a pageflip). Hence the load
detect code needs to grab the crtc of any output pipes it touches
(but only if it touches state used by the pageflip or cursor
ioctls).
- Atomic pageflip when moving planes. The first case is sane hw, where
planes have a fixed association with crtcs - nothing needs to be
done there. More insane^Wflexible hw needs to have plane->crtc
mapping which is separately protect with a lock that nests within
the crtc lock. If the plane is unused we can just assign it to the
current crtc and continue. But if a plane is already in use by
another crtc we can't just reassign it.
Two solution present themselves: Either go back to a slow-path which
takes all modeset locks, potentially incure quite a hefty delay. Or
simply disallowing such changes in one atomic pageflip - in general
the vblanks of two crtcs are not synced, so there's no sane way to
atomically flip such plane changes accross more than one crtc. I'd
heavily favour the later approach, going as far as mandating it as
part of the ABI of such a new a nuclear pageflip.
And if we _really_ want such semantics, we can always get them by
introducing another pageflip mutex between the mode_config.mutex and
the individual crtc locks. Pageflips crossing more than one crtc
would then need to take that lock first, to lock out concurrent
multi-crtc pageflips.
- Optimized global modeset operations: We could just take the
mode_config lock and then lazily lock all crtc which are affected by
a modeset operation. This has the advantage that pageflip could
continue unhampered on unaffected crtc. But if e.g. global resources
like plls need to be reassigned and so affect unrelated crtcs we can
still do that - nested locking works in any order.
This patch just adds the locks and takes them in drm_modeset_lock_all,
no real locking changes yet.
v2: Need to initialize the new lock in crtc_init and lock it righ
away, for otherwise the modeset_unlock_all below will try to unlock a
not-locked mutex.
Reviewed-by: Rob Clark <rob@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
David Herrmann