Having introduced per-context seqno, we now have a means to identity
progress across the system without feel of rollback as befell the
global_seqno. That is we can program a MI_SEMAPHORE_WAIT operation in
advance of submission safe in the knowledge that our target seqno and
address is stable.
However, since we are telling the GPU to busy-spin on the target address
until it matches the signaling seqno, we only want to do so when we are
sure that busy-spin will be completed quickly. To achieve this we only
submit the request to HW once the signaler is itself executing (modulo
preemption causing us to wait longer), and we only do so for default and
above priority requests (so that idle priority tasks never themselves
hog the GPU waiting for others).
As might be reasonably expected, HW semaphores excel in inter-engine
synchronisation microbenchmarks (where the 3x reduced latency / increased
throughput more than offset the power cost of spinning on a second ring)
and have significant improvement (can be up to ~10%, most see no change)
for single clients that utilize multiple engines (typically media players
and transcoders), without regressing multiple clients that can saturate
the system or changing the power envelope dramatically.
v3: Drop the older NEQ branch, now we pin the signaler's HWSP anyway.
v4: Tell the world and include it as part of scheduler caps.
Testcase: igt/gem_exec_whisper
Testcase: igt/benchmarks/gem_wsim
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190301170901.8340-3-chris@chris-wilson.co.uk
Change the license of the i915_sw_fence files to MIT matching
most of the other i915 files. This makes it possible to use them
in a new port of i915 to OpenBSD.
Besides some mechanical tree wide changes Chris Wilson is the sole
author of these files with Intel holding the copyright.
Intel's legal team have given permission to change the license according
to Joonas Lahtinen.
v2: expand commit message and note permission from Intel legal
Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181129013051.17525-1-jsg@jsg.id.au
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Merge tag 'drm-for-v4.13' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
"This is the main pull request for the drm, I think I've got one later
driver pull for mediatek SoC driver, I'm undecided on if it needs to
go to you yet.
Otherwise summary below:
Core drm:
- Atomic add driver private objects
- Deprecate preclose hook in modern drivers
- MST bandwidth tracking
- Use kvmalloc in more places
- Add mode_valid hook for crtc/encoder/bridge
- Reduce sync_file construction time
- Documentation updates
- New DRM synchronisation object support
New drivers:
- pl111 - pl111 CLCD display controller
Panel:
- Innolux P079ZCA panel driver
- Add NL12880B20-05, NL192108AC18-02D, P320HVN03 panels
- panel-samsung-s6e3ha2: Add s6e3hf2 panel support
i915:
- SKL+ watermark fixes
- G4x/G33 reset improvements
- DP AUX backlight improvements
- Buffer based GuC/host communication
- New getparam for (sub)slice infomation
- Cannonlake and Coffeelake initial patches
- Execbuf optimisations
radeon/amdgpu:
- Lots of Vega10 bug fixes
- Preliminary raven support
- KIQ support for compute rings
- MEC queue management rework
- DCE6 Audio support
- SR-IOV improvements
- Better radeon/amdgpu selection support
nouveau:
- HDMI stereoscopic support
- Display code rework for >= GM20x GPUs
msm:
- GEM rework for fine-grained locking
- Per-process pagetable work
- HDMI fixes for Snapdragon 820.
vc4:
- Remove 256MB CMA limit from vc4
- Add out-fence support
- Add support for cygnus
- Get/set tiling ioctls support
- Add T-format tiling support for scanout
zte:
- add VGA support.
etnaviv:
- Thermal throttle support for newer GPUs
- Restore userspace buffer cache performance
- dma-buf sync fix
stm:
- add stm32f429 display support
exynos:
- Rework vblank handling
- Fixup sw-trigger code
sun4i:
- V3s display engine support
- HDMI support for older SoCs
- Preliminary work on dual-pipeline SoCs.
rcar-du:
- VSP work
imx-drm:
- Remove counter load enable from PRE
- Double read/write reduction flag support
tegra:
- Documentation for the host1x and drm driver.
- Lots of staging ioctl fixes due to grate project work.
omapdrm:
- dma-buf fence support
- TILER rotation fixes"
* tag 'drm-for-v4.13' of git://people.freedesktop.org/~airlied/linux: (1270 commits)
drm: Remove unused drm_file parameter to drm_syncobj_replace_fence()
drm/amd/powerplay: fix bug fail to remove sysfs when rmmod amdgpu.
amdgpu: Set cik/si_support to 1 by default if radeon isn't built
drm/amdgpu/gfx9: fix driver reload with KIQ
drm/amdgpu/gfx8: fix driver reload with KIQ
drm/amdgpu: Don't call amd_powerplay_destroy() if we don't have powerplay
drm/ttm: Fix use-after-free in ttm_bo_clean_mm
drm/amd/amdgpu: move get memory type function from early init to sw init
drm/amdgpu/cgs: always set reference clock in mode_info
drm/amdgpu: fix vblank_time when displays are off
drm/amd/powerplay: power value format change for Vega10
drm/amdgpu/gfx9: support the amdgpu.disable_cu option
drm/amd/powerplay: change PPSMC_MSG_GetCurrPkgPwr for Vega10
drm/amdgpu: Make amdgpu_cs_parser_init static (v2)
drm/amdgpu/cs: fix a typo in a comment
drm/amdgpu: Fix the exported always on CU bitmap
drm/amdgpu/gfx9: gfx_v9_0_enable_gfx_static_mg_power_gating() can be static
drm/amdgpu/psp: upper_32_bits/lower_32_bits for address setup
drm/amd/powerplay/cz: print message if smc message fails
drm/amdgpu: fix typo in amdgpu_debugfs_test_ib_init
...
Rename:
wait_queue_t => wait_queue_entry_t
'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.
Start sorting this out by renaming it to 'wait_queue_entry_t'.
This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
My original intention was for i915_sw_fence to be the base class and
provide the reference count for the container. This was from starting
with a design to handle async_work. In practice, for i915 we embed
fences into structs which have their own independent reference counting,
making the i915_sw_fence.kref duplicitous. If we remove the kref, we
remove the i915_sw_fence's ability to free itself and its independence,
it can only exist within a container and must be supplied with a
callback to handle its release.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-1-chris@chris-wilson.co.uk
Add the tracking required to enable debugobjects for fences to improve
error detection in BAT. The debugobject interface lets us track the
lifetime and phases of the fences even while being embedded into larger
structs, i.e. to check they are not used after they have been released.
v2: Don't populate the stubs, debugobjects checks for a NULL pointer and
treats it equivalently.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161125131718.20978-4-chris@chris-wilson.co.uk
Currently, we have an active reference for the request until it is
retired. Though it cannot be retired before it has been executed by
hardware, the request may be completed before we have finished
processing the execute fence, i.e. we may continue to process that fence
as we free the request.
Fixes: 5590af3e11 ("drm/i915: Drive request submission through fence callbacks")
Fixes: 23902e49c9 ("drm/i915: Split request submit/execute phase into two")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161125131718.20978-3-chris@chris-wilson.co.uk
Localise the static struct lock_class_key to the caller of
i915_sw_fence_init() so that we create a lock_class instance for each
unique sw_fence rather than all sw_fences sharing the same
lock_class. This eliminate some lockdep false positive when using fences
from within fence callbacks.
For the relatively small number of fences currently in use [2], this adds
160 bytes of unused text/code when lockdep is disabled. This seems
quite high, but fully reducing it via ifdeffery is also quite ugly.
Removing the #fence strings saves 72 bytes with just a single #ifdef.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161114204105.29171-1-chris@chris-wilson.co.uk
In forthcoming patches, we want to be able to dynamically allocate the
wait_queue_t used whilst awaiting. This is more convenient if we extend
the i915_sw_fence_await_sw_fence() to perform the allocation for us if
we pass in a gfp mask as an alternative than a preallocated struct.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161028125858.23563-2-chris@chris-wilson.co.uk
This is really a core kernel struct in disguise until we can finally
place it in kernel/. There is an immediate need for a fence collection
mechanism that is more flexible than fence-array, in particular being
able to easily drive request submission via events (and not just
interrupt driven). The same mechanism would be useful for handling
nonblocking and asynchronous atomic modesets, parallel execution and
more, but for the time being just create a local sw fence for execbuf.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160909131201.16673-1-chris@chris-wilson.co.uk
Chris Wilson