As we now protect the timeline list using RCU, we can drop the
timeline->mutex for guarding the list iteration during context close, as
we are searching for an inflight request. Any new request will see the
context is banned and not be submitted. In doing so, pull the checks for
a concurrent submission of the request (notably the
i915_request_completed()) under the engine spinlock, to fully serialise
with __i915_request_submit()). That is in the case of preempt-to-busy
where the request may be completed during the __i915_request_submit(),
we need to be careful that we sample the request status after
serialising so that we don't miss the request the engine is actually
submitting.
Fixes: 4a31741521 ("drm/i915/gem: Refine occupancy test in kill_context()")
References: d22d2d073e ("drm/i915: Protect i915_request_await_start from early waits") # rcu protection of timeline->requests
References: https://gitlab.freedesktop.org/drm/intel/-/issues/1622
References: https://gitlab.freedesktop.org/drm/intel/-/issues/2158
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200806105954.7766-1-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
The obj->lut_list is traversed when the object is closed as the file
table is destroyed during process termination. As this occurs before we
kill any outstanding context if, due to some bug or another, the closure
is blocked, then we fail to shootdown any inflight operations
potentially leaving the GPU spinning forever. As we only need to guard
the list against concurrent closures and insertions, the hold is short
and merits being treated as a simple spinlock.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701084439.17025-1-chris@chris-wilson.co.uk
Catch up with upstream, in particular to get c1e8d7c6a7 ("mmap locking
API: convert mmap_sem comments").
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Start using device specific parameters instead of module parameters for
most things. The module parameters become the immutable initial values
for i915 parameters. The device specific parameters in i915->params
start life as a copy of i915_modparams. Any later changes are only
reflected in the debugfs.
The stragglers are:
* i915.force_probe and i915.modeset. Needed before dev_priv is
available. This is fine because the parameters are read-only and never
modified.
* i915.verbose_state_checks. Passing dev_priv to I915_STATE_WARN and
I915_STATE_WARN_ON would result in massive and ugly churn. This is
handled by not exposing the parameter via debugfs, and leaving the
parameter writable in sysfs. This may be fixed up in follow-up work.
* i915.inject_probe_failure. Only makes sense in terms of the module,
not the device. This is handled by not exposing the parameter via
debugfs.
v2: Fix uc i915 lookup code (Michał Winiarski)
Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila@intel.com>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200618150402.14022-1-jani.nikula@intel.com
Pull i915 uaccess updates from Al Viro:
"Low-hanging fruit in i915; there are several trickier followups, but
that'll wait for the next cycle"
* 'uaccess.i915' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
i915:get_engines(): get rid of pointless access_ok()
i915: alloc_oa_regs(): get rid of pointless access_ok()
i915 compat ioctl(): just use drm_ioctl_kernel()
i915: switch copy_perf_config_registers_or_number() to unsafe_put_user()
i915: switch query_{topology,engine}_info() to copy_to_user()
Since the removal of the no-semaphore boosting, we rely on timeslicing to
reorder passed inter-dependency hogs across the engines. However, we
require preemption to support timeslicing into user payloads, and not all
machine support preemption so we do not universally enable timeslicing,
even when it would correctly preempt our own inter-engine semaphores.
Since timeslicing and semaphore priority deboosting is now disabled on
Broadwell/Braswell, we have to follow suite and not use semaphores.
Testcase: igt/gem_exec_schedule/semaphore-codependency # bdw/bsw
Fixes: 18e4af04d2 ("drm/i915: Drop no-semaphore boosting")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200521140617.30015-1-chris@chris-wilson.co.uk
(cherry picked from commit 0eb670aac2)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Since the removal of the no-semaphore boosting, we rely on timeslicing to
reorder passed inter-dependency hogs across the engines. However, we
require preemption to support timeslicing into user payloads, and not all
machine support preemption so we do not universally enable timeslicing,
even when it would correctly preempt our own inter-engine semaphores.
Since timeslicing and semaphore priority deboosting is now disabled on
Broadwell/Braswell, we have to follow suite and not use semaphores.
Testcase: igt/gem_exec_schedule/semaphore-codependency # bdw/bsw
Fixes: 18e4af04d2 ("drm/i915: Drop no-semaphore boosting")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200521140617.30015-1-chris@chris-wilson.co.uk
The history of i915_vma_close() is confusing, as is its use. As the
lifetime of the i915_vma is currently bounded by the object it is
attached to, we needed a means of identify when a vma was no longer in
use by userspace (via the user's fd). This is further complicated by
that only ppgtt vma should be closed at the user's behest, as the ggtt
were always shared.
Now that we attach the vma to a lut on the user's context, the open
count does indicate how many unique and open context/vm are referencing
this vma from the user. As such, we can and should just use the
open_count to track when the vma is still in use by userspace.
It's a poor man's replacement for reference counting.
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1193
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200422190558.30509-1-chris@chris-wilson.co.uk
If we want to percolate information back from the HW, up through the GEM
context, we need to wait until the intel_context is scheduled out for
the last time. This is handled by the retirement of the intel_context's
barrier, i.e. by listening to the pulse after the notional unpin. So
wait until the intel_context is finally retired before releasing the
engine, so that we can inspect the final context state and pass it on.
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/20200406155840.1728-3-chris@chris-wilson.co.uk
Now that we can peek at GEM->engines[] and obtain a reference to them
using RCU, do so for instances where we can safely iterate the
potentially old copy of the engines. For setting, we can do this when we
know the engine properties are copied over before swapping, so we know
the new engines already have the global property and we update the old
before they are discarded. For reading, we only need to be safe; as we
do so on behalf of the user, their races are their own problem.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200402124218.6375-1-chris@chris-wilson.co.uk
On Gen11 powergating half the execution units is a functional
requirement when using the VME samplers. Not fullfilling this
requirement can lead to hangs.
This unfortunately plays fairly poorly with the NOA requirements. NOA
requires a stable power configuration to maintain its configuration.
As a result using OA (and NOA feeding into it) so far has required us
to use a power configuration that can work for all contexts. The only
power configuration fullfilling this is powergating half the execution
units.
This makes performance analysis for 3D workloads somewhat pointless.
Failing to find a solution that would work for everybody, this change
introduces a new i915-perf stream open parameter that punts the
decision off to userspace. If this parameter is omitted, the existing
Gen11 behavior remains (half EU array powergating).
This change takes the initiative to move all perf related sseu
configuration into i915_perf.c
v2: Make parameter priviliged if different from default
v3: Fix context modifying its sseu config while i915-perf is enabled
v4: Always consider global sseu a privileged operation (Tvrtko)
Override req_sseu point in intel_sseu_make_rpcs() (Tvrtko)
Remove unrelated changes (Tvrtko)
v5: Some typos (Tvrtko)
Process sseu param in read_properties_unlocked() (Tvrtko)
v6: Actually commit the bits from v5...
Fixup some checkpath warnings
v7: Only compare engine uabi field (Chris)
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200317132222.2638719-3-lionel.g.landwerlin@intel.com
If we have a set of active engines marked as being non-persistent, we
lose track of those if the user replaces those engines with
I915_CONTEXT_PARAM_ENGINES. As part of our uABI contract is that
non-persistent requests are terminated if they are no longer being
tracked by the user's context (in order to prevent a lost request
causing an untracked and so unstoppable GPU hang), we need to apply the
same context cancellation upon changing engines.
v2: Track stale engines[] so we only reap at context closure.
v3: Tvrtko spotted races with closing contexts and set-engines, so add a
veneer of kill-everything paranoia to clean up after losing a race.
Fixes: a0e047156c ("drm/i915/gem: Make context persistence optional")
Testcase: igt/gem_ctx_peristence/replace
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/20200211144831.1011498-1-chris@chris-wilson.co.uk
To enable non-persistent contexts, we require a means of cancelling any
inflight work from that context. This is first done "gracefully" by
using preemption to kick the active context off the engine, and then
forcefully by resetting the engine if it is active. If we are unable to
reset the engine to remove hostile userspace, we should not allow
userspace to opt into using non-persistent contexts.
If the per-engine reset fails, we still do a full GPU reset, but that is
rare and usually indicative of much deeper issues. The damage is already
done. However, the goal of the interface to allow long running compute
jobs without causing collateral damage elsewhere, and if we are unable
to support that we should make that known by not providing the
interface (and falsely pretending we can).
Fixes: a0e047156c ("drm/i915/gem: Make context persistence optional")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200130164553.1937718-1-chris@chris-wilson.co.uk
Allocate only an internal intel_context for the kernel_context, forgoing
a global GEM context for internal use as we only require a separate
address space (for our own protection).
Now having weaned GT from requiring ce->gem_context, we can stop
referencing it entirely. This also means we no longer have to create random
and unnecessary GEM contexts for internal use.
GEM contexts are now entirely for tracking GEM clients, and intel_context
the execution environment on the GPU.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221160324.1073045-1-chris@chris-wilson.co.uk
All pinning must be done prior to i915_request_create, to avoid
timeline->mutex inversions.
Here we slightly abuse the context_barrier_task stages to utilise the
'skip' decision as an opportunity to acquire the pin on the new ppgtt.
Consider it s/skip/prepare/. At the moment, we only have on user of
context_barrier_task, so it might be worth breaking it down for the
specific task of set-vm and refactor it later if we find a second
purpose.
<4> [402.377487] WARNING: possible circular locking dependency detected
<4> [402.377493] 5.4.0-rc8-CI-CI_DRM_7491+ #1 Tainted: G U
<4> [402.377497] ------------------------------------------------------
<4> [402.377502] gem_exec_parall/2506 is trying to acquire lock:
<4> [402.377507] ffff888403cdac70 (&kernel#2){+.+.}, at: i915_request_create+0x16/0x1c0 [i915]
<4> [402.377593]
but task is already holding lock:
<4> [402.377597] ffff88835efad550 (&ppgtt->pin_mutex){+.+.}, at: gen6_ppgtt_pin+0x4d/0x110 [i915]
<4> [402.377660]
which lock already depends on the new lock.
<4> [402.377664]
the existing dependency chain (in reverse order) is:
<4> [402.377668]
-> #1 (&ppgtt->pin_mutex){+.+.}:
<4> [402.377674] __mutex_lock+0x9a/0x9d0
<4> [402.377713] gen6_ppgtt_pin+0x4d/0x110 [i915]
<4> [402.377756] emit_ppgtt_update+0x1dc/0x370 [i915]
<4> [402.377801] context_barrier_task+0x176/0x310 [i915]
<4> [402.377844] ctx_setparam+0x400/0xb10 [i915]
<4> [402.377886] i915_gem_context_setparam_ioctl+0xc8/0x160 [i915]
<4> [402.377891] drm_ioctl_kernel+0xa7/0xf0
<4> [402.377895] drm_ioctl+0x2e1/0x390
<4> [402.377899] do_vfs_ioctl+0xa0/0x6f0
<4> [402.377903] ksys_ioctl+0x35/0x60
<4> [402.377906] __x64_sys_ioctl+0x11/0x20
<4> [402.377910] do_syscall_64+0x4f/0x210
<4> [402.377914] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [402.377917]
-> #0 (&kernel#2){+.+.}:
<4> [402.377923] __lock_acquire+0x1328/0x15d0
<4> [402.377926] lock_acquire+0xa7/0x1c0
<4> [402.377930] __mutex_lock+0x9a/0x9d0
<4> [402.377977] i915_request_create+0x16/0x1c0 [i915]
<4> [402.378013] intel_engine_flush_barriers+0x4c/0x100 [i915]
<4> [402.378062] i915_ggtt_pin+0x7d/0x130 [i915]
<4> [402.378108] gen6_ppgtt_pin+0x9c/0x110 [i915]
<4> [402.378148] ring_context_pin+0x2e/0xc0 [i915]
<4> [402.378183] __intel_context_do_pin+0x6b/0x190 [i915]
<4> [402.378226] i915_gem_do_execbuffer+0x180c/0x26b0 [i915]
<4> [402.378268] i915_gem_execbuffer2_ioctl+0x11b/0x460 [i915]
<4> [402.378272] drm_ioctl_kernel+0xa7/0xf0
<4> [402.378275] drm_ioctl+0x2e1/0x390
<4> [402.378279] do_vfs_ioctl+0xa0/0x6f0
<4> [402.378282] ksys_ioctl+0x35/0x60
<4> [402.378286] __x64_sys_ioctl+0x11/0x20
<4> [402.378289] do_syscall_64+0x4f/0x210
<4> [402.378292] entry_SYSCALL_64_after_hwframe+0x49/0xbe
<4> [402.378295]
other info that might help us debug this:
<4> [402.378299] Possible unsafe locking scenario:
<4> [402.378302] CPU0 CPU1
<4> [402.378305] ---- ----
<4> [402.378307] lock(&ppgtt->pin_mutex);
<4> [402.378310] lock(&kernel#2);
<4> [402.378314] lock(&ppgtt->pin_mutex);
<4> [402.378317] lock(&kernel#2);
<4> [402.378320]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191206105527.1130413-4-chris@chris-wilson.co.uk
Pull more drm updates from Dave Airlie:
"Rob pointed out I missed his pull request for msm-next, it's been in
next for a while outside of my tree so shouldn't cause any unexpected
issues, it has some OCMEM support in drivers/soc that is acked by
other maintainers as it's outside my tree.
Otherwise it's a usual fixes pull, i915, amdgpu, the main ones, with
some tegra, omap, mgag200 and one core fix.
Summary:
msm-next:
- OCMEM support for a3xx and a4xx GPUs.
- a510 support + display support
core:
- mst payload deletion fix
i915:
- uapi alignment fix
- fix for power usage regression due to security fixes
- change default preemption timeout to 640ms from 100ms
- EHL voltage level display fixes
- TGL DGL PHY fix
- gvt - MI_ATOMIC cmd parser fix, CFL non-priv warning
- CI spotted deadlock fix
- EHL port D programming fix
amdgpu:
- VRAM lost fixes on BACO for CI/VI
- navi14 DC fixes
- misc SR-IOV, gfx10 fixes
- XGMI fixes for arcturus
- SRIOV fixes
amdkfd:
- KFD on ppc64le enabled
- page table optimisations
radeon:
- fix for r1xx/2xx register checker.
tegra:
- displayport regression fixes
- DMA API regression fixes
mgag200:
- fix devices that can't scanout except at 0 addr
omap:
- fix dma_addr refcounting"
* tag 'drm-next-2019-12-06' of git://anongit.freedesktop.org/drm/drm: (100 commits)
drm/dp_mst: Correct the bug in drm_dp_update_payload_part1()
drm/omap: fix dma_addr refcounting
drm/tegra: Run hub cleanup on ->remove()
drm/tegra: sor: Make the +5V HDMI supply optional
drm/tegra: Silence expected errors on IOMMU attach
drm/tegra: vic: Export module device table
drm/tegra: sor: Implement system suspend/resume
drm/tegra: Use proper IOVA address for cursor image
drm/tegra: gem: Remove premature import restrictions
drm/tegra: gem: Properly pin imported buffers
drm/tegra: hub: Remove bogus connection mutex check
ia64: agp: Replace empty define with do while
agp: Add bridge parameter documentation
agp: remove unused variable num_segments
agp: move AGPGART_MINOR to include/linux/miscdevice.h
agp: remove unused variable size in agp_generic_create_gatt_table
drm/dp_mst: Fix build on systems with STACKTRACE_SUPPORT=n
drm/radeon: fix r1xx/r2xx register checker for POT textures
drm/amdgpu: fix GFX10 missing CSIB set(v3)
drm/amdgpu: should stop GFX ring in hw_fini
...
