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5 commits

Author SHA1 Message Date
Daniel Vetter
ea0dd85a75 drm/doc: use preferred struct reference in kernel-doc
sed -e 's/\( \* .*\)struct &\([_a-z]*\)/\1\&struct \2/' -i

Originally I wasnt a friend of this style because I thought a
line-break between the "&struct" and "foo" part would break it. But a
quick test shows that " * &struct \n * foo\n" works pefectly well with
current kernel-doc. So time to mass-apply these changes!

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-6-git-send-email-daniel.vetter@ffwll.ch
2016-12-30 13:34:59 +01:00
Daniel Vetter
613051dac4 drm: locking&new iterators for connector_list
The requirements for connector_list locking are a bit tricky:
- We need to be able to jump over zombie conectors (i.e. with refcount
  == 0, but not yet removed from the list). If instead we require that
  there's no zombies on the list then the final kref_put must happen
  under the list protection lock, which means that locking context
  leaks all over the place. Not pretty - better to deal with zombies
  and wrap the locking just around the list_del in the destructor.

- When we walk the list we must _not_ hold the connector list lock. We
  walk the connector list at an absolutely massive amounts of places,
  if all those places can't ever call drm_connector_unreference the
  code would get unecessarily complicated.

- connector_list needs it own lock, again too many places that walk it
  that we could reuse e.g. mode_config.mutex without resulting in
  inversions.

- Lots of code uses these loops to look-up a connector, i.e. they want
  to be able to call drm_connector_reference. But on the other hand we
  want connectors to stay on that list until they're dead (i.e.
  connector_list can't hold a full reference), which means despite the
  "can't hold lock for the loop body" rule we need to make sure a
  connector doesn't suddenly become a zombie.

At first Dave&I discussed various horror-show approaches using srcu,
but turns out it's fairly easy:

- For the loop body we always hold an additional reference to the
  current connector. That means it can't zombify, and it also means
  it'll stay on the list, which means we can use it as our iterator to
  find the next connector.

- When we try to find the next connector we only have to jump over
  zombies. To make sure we don't chase bad pointers that entire loop
  is protected with the new connect_list_lock spinlock. And because we
  know that we're starting out with a non-zombie (need to drop our
  reference for the old connector only after we have our new one),
  we're guranteed to still be on the connector_list and either find
  the next non-zombie or complete the iteration.

- Only downside is that we need to make sure that the temporary
  reference for the loop body doesn't leak. iter_get/put() functions +
  lockdep make sure that's the case.

- To avoid a flag day the new iterator macro has an _iter postfix. We
  can rename it back once all the users of the unsafe version are gone
  (there's about 100 list walkers for the connector_list).

For now this patch only converts all the list walking in the core,
leaving helpers and drivers for later patches. The nice thing is that
we can now finally remove 2 FIXME comments from the
register/unregister functions.

v2:
- use irqsafe spinlocks, so that we can use this in drm_state_dump
  too.
- nuke drm_modeset_lock_all from drm_connector_init, now entirely
  cargo-culted nonsense.

v3:
- do {} while (!kref_get_unless_zero), makes for a tidier loop (Dave).
- pretty kerneldoc
- add EXPORT_SYMBOL, helpers&drivers are supposed to use this.

v4: Change lockdep annotations to only check whether we release the
iter fake lock again (i.e. make sure that iter_put is called), but
not check any locking dependecies itself. That seams to require a
recursive read lock in trylock mode.

Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161213230814.19598-6-daniel.vetter@ffwll.ch
2016-12-18 14:32:35 +01:00
Gustavo Padovan
beaf5af480 drm/fence: add out-fences support
Support DRM out-fences by creating a sync_file with a fence for each CRTC
that sets the OUT_FENCE_PTR property.

We use the out_fence pointer received in the OUT_FENCE_PTR prop to send
the sync_file fd back to userspace.

The sync_file and fd are allocated/created before commit, but the
fd_install operation only happens after we know that commit succeed.

v2: Comment by Rob Clark:
	- Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here.

    Comment by Daniel Vetter:
	- Add clean up code for out_fences

v3: Comments by Daniel Vetter:
	- create DRM_MODE_ATOMIC_EVENT_MASK
	- userspace should fill out_fences_ptr with the crtc_ids for which
	it wants fences back.

v4: Create OUT_FENCE_PTR properties and remove old approach.

v5: Comments by Brian Starkey:
	- Remove extra fence_get() in atomic_ioctl()
	- Check ret before iterating on the crtc_state
	- check ret before fd_install
	- set fence_state to NULL at the beginning
	- check fence_state->out_fence_ptr before put_user()
	- change order of fput() and put_unused_fd() on failure

     - Add access_ok() check to the out_fence_ptr received
     - Rebase after fence -> dma_fence rename
     - Store out_fence_ptr in the drm_atomic_state
     - Split crtc_setup_out_fence()
     - return -1 as out_fence with TEST_ONLY flag

v6: Comments by Daniel Vetter
	- Add prepare/unprepare_crtc_signaling()
	- move struct drm_out_fence_state to drm_atomic.c
	- mark get_crtc_fence() as static

    Comments by Brian Starkey
	- proper set fence_ptr fence_state array
	- isolate fence_idx increment

    - improve error handling

v7: Comments by Daniel Vetter
	- remove prefix from internal functions
	- make out_fence_ptr an s64 pointer
	- degrade DRM_INFO to DRM_DEBUG_ATOMIC when put_user fail
	- fix doc issues
	- filter out OUT_FENCE_PTR == NULL and do not fail in this case
	- add complete_crtc_signalling()
	- krealloc fence_state on demand

    Comment by Brian Starkey
	- remove unused crtc_state arg from get_out_fence()

v8: Comment by Brian Starkey
	- cancel events before check for !fence_state
	- convert a few lefovers u64 types for out_fence_ptr
	- fix memleak by assign fence_state earlier after realloc
	- proper accout num_fences in case of error

v9: Comment by Brian Starkey
	- memset last position of fence_state after krealloc
    Comments by Sean Paul
	- pass install_fds in complete_crtc_signaling() instead of ret

     - put_user(-1, fence_ptr) when decoding props

v10: Comment by Brian Starkey
	- remove unneeded num_fences increment on error path
	- kfree fence_state after installing fences fd

v11: rebase against latest drm-misc

v12: rebase again against latest drm-misc

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Brian Starkey <brian.starkey@arm.com> (v10)
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Robert Foss <robert.foss@collabora.com> (v10)
[danvet: Appease checkpatch.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1479301221-13056-1-git-send-email-gustavo@padovan.org
2016-11-16 14:36:27 +01:00
Gustavo Padovan
9626014258 drm/fence: add in-fences support
There is now a new property called IN_FENCE_FD attached to every plane
state that receives sync_file fds from userspace via the atomic commit
IOCTL.

The fd is then translated to a fence (that may be a fence_array
subclass or just a normal fence) and then used by DRM to fence_wait() for
all fences in the sync_file to signal. So it only commits when all
framebuffers are ready to scanout.

v2: Comments by Daniel Vetter:
	- remove set state->fence = NULL in destroy phase
	- accept fence -1 as valid and just return 0
	- do not call fence_get() - sync_file_fences_get() already calls it
	- fence_put() if state->fence is already set, in case userspace
	set the property more than once.

v3: WARN_ON if fence is set but state has no FB

v4: Comment from Maarten Lankhorst
	- allow set fence with no related fb

v5: rename FENCE_FD to IN_FENCE_FD

v6: Comments by Daniel Vetter:
	- rename plane_state->in_fence back to "fence"
	- re-introduce WARN_ON if fence set but no fb

     - rebase after fence -> dma_fence rename

v7: Comments by Brian Starkey
	- set state->fence to NULL when duplicating the state
	- fail if IN_FENCE_FD was already set

v8: rebase against latest drm-misc

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Robert Foss <robert.foss@collabora.com>
[danvet: Rebase onto extracted drm_mode_config.[hc].]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-11-16 09:55:27 +01:00
Daniel Vetter
28575f165d drm: Extract drm_mode_config.[hc]
And shuffle the kernel-doc structure a bit since drm_crtc.[hc] now
only contains CRTC-related functions and structures.

v2:
- rebase onto drm-misc
- don't forget to move drm_mode_config_cleanup.
- move 2 internal decls under the right heading (Chris)

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2016-11-15 15:23:29 +01:00