linux.git/include/drm/drm_syncobj.h, branch v6.12.80

drm/syncobj: add IOCTL to register an eventfd

2023-07-20T10:01:03+00:00

Introduce a new DRM_IOCTL_SYNCOBJ_EVENTFD IOCTL which signals an
eventfd from a syncobj.

This is useful for Wayland compositors to handle wait-before-submit.
Wayland clients can send a timeline point to the compositor
before the point has materialized yet, then compositors can wait
for the point to materialize via this new IOCTL.

The existing DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT IOCTL is not suitable
because it blocks. Compositors want to integrate the wait with
their poll(2)-based event loop.

Requirements for new uAPI:

- User-space patch: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4262
- IGT: https://lists.freedesktop.org/archives/igt-dev/2023-July/057893.html

v2:
- Wait for fence when flags is zero
- Improve documentation (Pekka)
- Rename IOCTL (Christian)
- Fix typo in drm_syncobj_add_eventfd() (Christian)

v3:
- Link user-space + IGT patches
- Add reference from overview docs

v4: fix IOCTL number conflict with GETFB2 (Nicholas Choi, Vitaly Prosyak)

Signed-off-by: Simon Ser 
Reviewed-by: Christian König 
Acked-by: Pekka Paalanen 
Cc: Jason Ekstrand 
Cc: Daniel Vetter 
Cc: Bas Nieuwenhuizen 
Cc: Daniel Stone 
Cc: James Jones 
Cc: Austin Shafer 
Cc: Vitaly Prosyak 
Link: https://patchwork.freedesktop.org/patch/msgid/20230714111257.11940-1-contact@emersion.fr

drm/syncobj: add new drm_syncobj_add_point interface v4

2019-04-01T10:05:53+00:00

Use the dma_fence_chain object to create a timeline of fence objects
instead of just replacing the existing fence.

v2: rebase and cleanup
v3: fix garbage collection parameters
v4: add unorder point check, print a warn calltrace

Signed-off-by: Christian König 
Reviewed-by: Lionel Landwerlin 
Link: https://patchwork.freedesktop.org/patch/295780/?series=58813&rev=1

Merge tag 'topic/drmp-cleanup-2019-01-02' of git://anongit.freedesktop.org/drm/drm-intel into drm-misc-next

2019-01-07T15:43:24+00:00

Make some drm headers self-contained with includes and forward declarations

Signed-off-by: Maxime Ripard 

# gpg: Signature made Wed 02 Jan 2019 10:47:51 AM CET
# gpg:                using RSA key 1565A65B77B0632E1124E59CD398079D26ABEE6F
# gpg: Can't check signature: No public key
From: Jani Nikula 
Link: https://patchwork.freedesktop.org/patch/msgid/87pntfl6pa.fsf@intel.com

drm: forward declare struct drm_file in drm_syncobj.h

2019-01-02T09:38:08+00:00

drm_syncobj.h uses struct drm_file pointers, forward declare struct
drm_file to make the header self-contained. This prepares for dropping
drmP.h from files including drm_syncobj.h.

Switch from "" to <> includes while at it.

v2: forward declare instead of including drm_file.h (Daniel)

[Updated commit message per Laurent's review while applying.]

Cc: Sam Ravnborg 
Cc: Daniel Vetter 
Cc: Laurent Pinchart 
Reviewed-by: Daniel Vetter 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Jani Nikula 
Link: https://patchwork.freedesktop.org/patch/msgid/20181228082815.10797-1-jani.nikula@intel.com

drm/syncobj: remove drm_syncobj_cb and cleanup

2018-12-11T16:38:38+00:00

This completes "drm/syncobj: Drop add/remove_callback from driver
interface" and cleans up the implementation a bit.

Signed-off-by: Christian König 
Reviewed-by: Chunming Zhou 
Link: https://patchwork.freedesktop.org/patch/266255/

drm: revert "expand replace_fence to support timeline point v2"

2018-12-05T10:01:11+00:00

This reverts commit 9a09a42369a4a37a959c051d8e1a1f948c1529a4.

The whole interface isn't thought through. Since this function can't
fail we actually can't allocate an object to store the sync point.

Sorry, I should have taken the lead on this from the very beginning and
reviewed it more thoughtfully. Going to propose a new interface as a
follow up change.

Signed-off-by: Christian König 
Reviewed-by: Chunming Zhou 
Link: https://patchwork.freedesktop.org/patch/265580/

drm: Revert syncobj timeline changes.

2018-11-12T11:54:21+00:00

Daniel suggested I submit this, since we're still seeing regressions
from it.  This is a revert to before 48197bc564c7 ("drm: add syncobj
timeline support v9") and its followon fixes.

Fixes this on first V3D testcase execution:

[   48.767088] ============================================
[   48.772410] WARNING: possible recursive locking detected
[   48.777739] 4.19.0-rc6+ #489 Not tainted
[   48.781668] --------------------------------------------
[   48.786993] shader_runner/3284 is trying to acquire lock:
[   48.792408] ce309d7f (&(&array->lock)->rlock){....}, at: dma_fence_add_callback+0x30/0x23c
[   48.800714]
[   48.800714] but task is already holding lock:
[   48.806559] c5952bd3 (&(&array->lock)->rlock){....}, at: dma_fence_add_callback+0x30/0x23c
[   48.814862]
[   48.814862] other info that might help us debug this:
[   48.821410]  Possible unsafe locking scenario:
[   48.821410]
[   48.827338]        CPU0
[   48.829788]        ----
[   48.832239]   lock(&(&array->lock)->rlock);
[   48.836434]   lock(&(&array->lock)->rlock);
[   48.840640]
[   48.840640]  *** DEADLOCK ***
[   48.840640]
[   48.846582]  May be due to missing lock nesting notation
[  130.763560] 1 lock held by cts-runner/3270:
[  130.767745]  #0: 7834b793 (&(&array->lock)->rlock){-...}, at: dma_fence_add_callback+0x30/0x23c
[  130.776461]
               stack backtrace:
[  130.780825] CPU: 1 PID: 3270 Comm: cts-runner Not tainted 4.19.0-rc6+ #486
[  130.787706] Hardware name: Broadcom STB (Flattened Device Tree)
[  130.793645] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[  130.801404] [] (show_stack) from [] (dump_stack+0xa8/0xd4)
[  130.808642] [] (dump_stack) from [] (__lock_acquire+0x848/0x1a68)
[  130.816483] [] (__lock_acquire) from [] (lock_acquire+0xd8/0x22c)
[  130.824326] [] (lock_acquire) from [] (_raw_spin_lock_irqsave+0x54/0x68)
[  130.832777] [] (_raw_spin_lock_irqsave) from [] (dma_fence_add_callback+0x30/0x23c)
[  130.842183] [] (dma_fence_add_callback) from [] (dma_fence_array_enable_signaling+0x58/0xec)
[  130.852371] [] (dma_fence_array_enable_signaling) from [] (dma_fence_add_callback+0xe8/0x23c)
[  130.862647] [] (dma_fence_add_callback) from [] (drm_syncobj_wait_ioctl+0x518/0x614)
[  130.872143] [] (drm_syncobj_wait_ioctl) from [] (drm_ioctl_kernel+0xb0/0xf0)
[  130.880940] [] (drm_ioctl_kernel) from [] (drm_ioctl+0x1d8/0x390)
[  130.888782] [] (drm_ioctl) from [] (do_vfs_ioctl+0xb0/0x8ac)
[  130.896187] [] (do_vfs_ioctl) from [] (ksys_ioctl+0x34/0x60)
[  130.903593] [] (ksys_ioctl) from [] (ret_fast_syscall+0x0/0x28)

Cc: Chunming Zhou 
Cc: Christian König 
Cc: Daniel Vetter 
Signed-off-by: Eric Anholt 
Acked-by: Christian König 
Signed-off-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/261044/

drm/syncobj: disable the timeline UAPI for now v2

2018-11-08T10:31:34+00:00

Until we have sorted out all problems.

v2: return -EINVAL during create if flag is set.

Signed-off-by: Christian König 
Reviewed-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/260937/

drm: fix deadlock of syncobj v6

2018-10-23T11:58:56+00:00

v2:
add a mutex between sync_cb execution and free.
v3:
clearly separating the roles for pt_lock and cb_mutex (Chris)
v4:
the cb_mutex should be taken outside of the pt_lock around
this if() block. (Chris)
v5:
fix a corner case
v6:
tidy drm_syncobj_fence_get_or_add_callback up. (Chris)

Tested by syncobj_basic and syncobj_wait of igt.

Signed-off-by: Chunming Zhou 
Cc: Daniel Vetter 
Cc: Chris Wilson 
Cc: Christian König 
Cc: intel-gfx@lists.freedesktop.org
Reviewed-by: Chris Wilson 
Signed-off-by: Christian König 
Link: https://patchwork.kernel.org/patch/10652893/

drm: add syncobj timeline support v9

2018-10-18T11:46:48+00:00

This patch is for VK_KHR_timeline_semaphore extension, semaphore is called syncobj in kernel side:
This extension introduces a new type of syncobj that has an integer payload
identifying a point in a timeline. Such timeline syncobjs support the
following operations:
   * CPU query - A host operation that allows querying the payload of the
     timeline syncobj.
   * CPU wait - A host operation that allows a blocking wait for a
     timeline syncobj to reach a specified value.
   * Device wait - A device operation that allows waiting for a
     timeline syncobj to reach a specified value.
   * Device signal - A device operation that allows advancing the
     timeline syncobj to a specified value.

v1:
Since it's a timeline, that means the front time point(PT) always is signaled before the late PT.
a. signal PT design:
Signal PT fence N depends on PT[N-1] fence and signal opertion fence, when PT[N] fence is signaled,
the timeline will increase to value of PT[N].
b. wait PT design:
Wait PT fence is signaled by reaching timeline point value, when timeline is increasing, will compare
wait PTs value with new timeline value, if PT value is lower than timeline value, then wait PT will be
signaled, otherwise keep in list. syncobj wait operation can wait on any point of timeline,
so need a RB tree to order them. And wait PT could ahead of signal PT, we need a sumission fence to
perform that.

v2:
1. remove unused DRM_SYNCOBJ_CREATE_TYPE_NORMAL. (Christian)
2. move unexposed denitions to .c file. (Daniel Vetter)
3. split up the change to drm_syncobj_find_fence() in a separate patch. (Christian)
4. split up the change to drm_syncobj_replace_fence() in a separate patch.
5. drop the submission_fence implementation and instead use wait_event() for that. (Christian)
6. WARN_ON(point != 0) for NORMAL type syncobj case. (Daniel Vetter)

v3:
1. replace normal syncobj with timeline implemenation. (Vetter and Christian)
    a. normal syncobj signal op will create a signal PT to tail of signal pt list.
    b. normal syncobj wait op will create a wait pt with last signal point, and this wait PT is only signaled by related signal point PT.
2. many bug fix and clean up
3. stub fence moving is moved to other patch.

v4：
1. fix RB tree loop with while(node=rb_first(...)). (Christian)
2. fix syncobj lifecycle. (Christian)
3. only enable_signaling when there is wait_pt. (Christian)
4. fix timeline path issues.
5. write a timeline test in libdrm

v5: (Christian)
1. semaphore is called syncobj in kernel side.
2. don't need 'timeline' characters in some function name.
3. keep syncobj cb.

v6: (Christian)
1. merge syncobj_timeline to syncobj structure.
2. simplify some check sentences.
3. some misc change.
4. fix CTS failed issue.

v7: (Christian)
1. error handling when creating signal pt.
2. remove timeline naming in func.
3. export flags in find_fence.
4. allow reset timeline.

v8:
1. use wait_event_interruptible without timeout
2. rename _TYPE_INDIVIDUAL to _TYPE_BINARY

v9:
1. rename signal_pt->base to signal_pt->fence_array to avoid misleading
2. improve kerneldoc

individual syncobj is tested by ./deqp-vk -n dEQP-VK*semaphore*
timeline syncobj is tested by ./amdgpu_test -s 9

Signed-off-by: Chunming Zhou 
Signed-off-by: Christian König 
Cc: Christian Konig 
Cc: Dave Airlie 
Cc: Daniel Rakos 
Cc: Daniel Vetter 
Cc: Bas Nieuwenhuizen 
Cc: Jason Ekstrand 
Reviewed-by: Christian König 
Acked-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/257258/