Cleanup intel_lrc.h by moving some of the residual common register
definitions into intel_lrc_reg.h, prior to rebranding and splitting off
the submission backends.
v2: keep the SCHEDULE enum in the old file, since it is specific to the
gvt usage of the execlists submission backend (John)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> #v2
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209233618.4287-1-chris@chris-wilson.co.uk
Tigerlake is plagued by spontaneous DMAR faults [reason 7, next page
table ptr is invalid] which lead to GPU hangs. These faults occur when
an iommu map is immediately reused. Adding further clflushes and
barriers around either the GTT PTE or iommu PTE updates do not prevent
the faults. So far the only effect has been from inducing a delay
between reuse of the iommu on the GPU, and applying the delay at the
iommu map allows for the smallest stable delay.
Note that such a delay is hideous and clearly does not fix the root cause,
and so should only be a bandaid until a complete solution is found. The
delay was determined by running igt/gem_exec_fence/parallel in a loop for
a few hours (unpatched MTBF is about 10s).
We have also seen such DMAR fault [reason 7] errors on other platforms,
notably gen9-gen11, but so far it has only been trivially and
consistently reproduced on Tigerlake.
v2: Leave a tell-tale to know when we apply the vt'd quirk, and as a
reminder to remove it again. Hopefully.
Testcase: igt/gem_exec_fence/parallel
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209164008.5487-2-chris@chris-wilson.co.uk
A call to wait for the GT to idle from inside the put_pages fallback is
prone to cause an uninterruptible livelock. As it does not provide
adequate serialisation with new requests, simply fallback to a trivial
sleep.
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/20201209164008.5487-1-chris@chris-wilson.co.uk
Document what a masked register is according to bspec so we avoid
developers using the wrong functions to implement WAs.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-3-lucas.demarchi@intel.com
The use of "masked" in this function is due to its history. Once upon a
time it received a mask and a value as parameter. Since
commit eeec73f8a4 ("drm/i915/gt: Skip rmw for masked registers")
that is not true anymore and now there is a clear and a set parameter.
Depending on the case, that can still be thought as a mask and value,
but there are some subtle differences: what we clear doesn't need to be
the same bits we are setting, particularly when we are using masked
registers.
The fact that we also have "masked registers", i.e. registers whose mask
is stored in the upper 16 bits of the register, makes it even more
confusing, because "masked" in wa_write_masked_or() has little to do
with masked registers, but rather refers to the old mask parameter the
function received (that can also, but not exclusively, be used to write
to masked register).
Avoid the ambiguity and misnomer by renaming it to something else,
hopefully less confusing: wa_write_clr_set(), to designate that we are
doing both clr and set operations in the register.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-2-lucas.demarchi@intel.com
When using masked registers, there is nothing to clear since a masked
register has the mask in the upper 16b: we can just write to the
location we want and use the mask to control what bits we are writing
to.
However that doesn't mean we don't want to read back the register and
check the value actually matched what we wanted to write, i.e. that
the WA stick. That should be an explicit opt-out for registers that are
either write-only or that are affected by hardware misbehavior.
Moreover both wa_masked_en() and wa_masked_dis() check the WA stick, so
skipping the check just because the field is more than 1 bit is
surprising and error-prone.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201209045246.2905675-1-lucas.demarchi@intel.com
Closed vma are protected by the GT wakeref held as we lookup the vma, so
we know that the vma will not be freed as we process it for the execbuf.
Instead we expect to catch the closed status of the context, and simply
allow the close-race on an individual vma to be washed away.
Longer term, the GT wakeref protection will be removed by explicit
vma.kref tracking.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2245
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/20201207193824.18114-1-chris@chris-wilson.co.uk
When we fail to find a single block large enough to require splitting,
report the largest block we did find.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201207130346.11849-1-chris@chris-wilson.co.uk
Currently the check that the unsigned size_t variable i is >= 0
is always true because the unsigned variable will never be negative,
causing the loop to run forever. Fix this by changing the
pre-decrement check to a zero check on i followed by a decrement of i.
Addresses-Coverity: ("Unsigned compared against 0")
Fixes: bfed6708d6 ("drm/i915: use vmap in shmem_pin_map")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201002170354.94627-1-colin.king@canonical.com
Remove the last macro and implement it as a function like the rest of
the operations that don't assume there is a `wal` list, but rather
receive it as argument.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-4-lucas.demarchi@intel.com
Just ommitting the list it's operating on doesn't save much typing
and adds another way to do the same thing. Just replace it with
wa_masked_dis().
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-3-lucas.demarchi@intel.com
Just ommitting the list it's operating on doesn't save much typing and
adds another way to do the same thing. Just replace it with
wa_masked_en().
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-2-lucas.demarchi@intel.com
Set GS Timer to 224 to prevent a HS/DS hang.
Bspec: 53508
v2: reword commit message and add comment explaining why read
verification is ignored (Chris)
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201205092542.2325477-1-lucas.demarchi@intel.com
Across a reset, we stop the engine but not the timers. This leaves a
window where the timers have inconsistent state with the engine, but
should only result in a spurious timeout. As we cancel the outstanding
events, also cancel their timers.
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/20201204151234.19729-4-chris@chris-wilson.co.uk
We currently presume that the engine reset is successful, cancelling the
expired preemption timer in the process. However, engine resets can
fail, leaving the timeout still pending and we will then respond to the
timeout again next time the tasklet fires. What we want is for the
failed engine reset to be promoted to a full device reset, which is
kicked by the heartbeat once the engine stops processing events.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1168
Fixes: 3a7a92aba8 ("drm/i915/execlists: Force preemption")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.5+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-2-chris@chris-wilson.co.uk
Before reseting the engine, we suspend the execution of the guilty
request, so that we can continue execution with a new context while we
slowly compress the captured error state for the guilty context. However,
if the reset fails, we will promptly attempt to reset the same request
again, and discover the ongoing capture. Ignore the second attempt to
suspend and capture the same request.
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1168
Fixes: 32ff621fd7 ("drm/i915/gt: Allow temporary suspension of inflight requests")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201204151234.19729-1-chris@chris-wilson.co.uk
In the course of discovering and closing many races with context closure
and execbuf submission, since commit 61231f6bd0 ("drm/i915/gem: Check
that the context wasn't closed during setup") we started checking that
the context was not closed by another userspace thread during the execbuf
ioctl. In doing so we cancelled the inflight request (by telling it to be
skipped), but kept reporting success since we do submit a request, albeit
one that doesn't execute. As the error is known before we return from the
ioctl, we can report the error we detect immediately, rather than leave
it on the fence status. With the immediate propagation of the error, it
is easier for userspace to handle.
Fixes: 61231f6bd0 ("drm/i915/gem: Check that the context wasn't closed during setup")
Testcase: igt/gem_ctx_exec/basic-close-race
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.7+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203103432.31526-1-chris@chris-wilson.co.uk
There is a copy and paste bug in this code. It's supposed to check
"obj2" instead of checking "obj" a second time.
Fixes: 80f0b679d6 ("drm/i915: Add an implementation for i915_gem_ww_ctx locking, v2.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/8ilneOcJAjwqU4t@mwand
Mixing I915_ALLOC_CONTIGUOUS and I915_ALLOC_MAX_SEGMENT_SIZE fared
badly. The two directives conflict, with the contiguous request setting
the min_order to the full size of the object, and the max-segment-size
setting the max_order to the limit of the DMA mapper. This results in a
situation where max_order < min_order, causing our sanity checks to
fail.
Instead of limiting the buddy block size, in the previous patch we split
the oversized buddy into multiple scatterlist elements.
Fixes: d2cf0125d4 ("drm/i915/lmem: Limit block size to 4G")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201202173444.14903-2-chris@chris-wilson.co.uk
Adhere to the i915_sg_max_segment() limit on the lengths of individual
scatterlist elements, and in doing so split up very large chunks of lmem
into manageable pieces for the dma-mapping backend.
Reported-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Suggested-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201202173444.14903-1-chris@chris-wilson.co.uk
Adding any kinds of "last" abi markers is usually a mistake which I
repeated when implementing the PMU because it felt convenient at the time.
This patch marks I915_PMU_LAST as deprecated and stops the internal
implementation using it for sizing the event status bitmask and array.
New way of sizing the fields is a bit less elegant, but it omits reserving
slots for tracking events we are not interested in, and as such saves some
runtime space. Adding sampling events is likely to be a special event and
the new plumbing needed will be easily detected in testing. Existing
asserts against the bitfield and array sizes are keeping the code safe.
First event which gets the new treatment in this new scheme are the
interrupts - which neither needs any tracking in i915 pmu nor needs
waking up the GPU to read it.
v2:
* Streamline helper names. (Chris)
v3:
* Comment which events need tracking. (Chris)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201131757.206367-1-tvrtko.ursulin@linux.intel.com
After a cursory check on the parameters to i915_gem_object_pin_map(),
where we return a precise error, if the backend rejects the mapping we
always return PTR_ERR(-ENOMEM). Let us also return a more precise error
here so we can differentiate between running out of memory and
programming errors (or situations where we may be trying different paths
and looking for an error from an unsupported map).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127195334.13134-1-chris@chris-wilson.co.uk
Block sizes are only limited by the largest power-of-two that will fit
in the region size, but to construct an object we also require feeding
it into an sg list, where the upper limit of the sg entry is at most
UINT_MAX. Therefore to prevent issues with allocating blocks that are
too large, add the flag I915_ALLOC_MAX_SEGMENT_SIZE which should limit
block sizes to the i915_sg_segment_size().
v2: (matt)
- query the max segment.
- prefer flag to limit block size to 4G, since it's best not to assume
the user will feed the blocks into an sg list.
- simple selftest so we don't have to guess.
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: CQ Tang <cq.tang@intel.com>
Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130134721.54457-1-matthew.auld@intel.com
For the LMEM case if we have suitable alignment and 2M physical pages we
should always get 2M GTT pages within the constraints of the hugepages
selftest. If we don't then something might be wrong in our construction
of the backing pages.
References: 330b7d3305 ("drm/i915/region: fix order when adding blocks")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130141809.65330-2-matthew.auld@intel.com
In igt_ppgtt_sanity_check we should also exercise the non-contiguous
option for LMEM, since this will give us slightly different sg layouts
and alignment.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201130141809.65330-1-matthew.auld@intel.com
We treat idling the GT (intel_rps_park) as a downclock event, and reduce
the frequency we intend to restart the GT with. Since the two workloads
are likely related (e.g. a compositor rendering every 16ms), we want to
carry the frequency and load information from across the idling.
However, we do also need to update the frequencies so that workloads
that run for less than 1ms are autotuned by RPS (otherwise we leave
compositors running at max clocks, draining excess power). Conversely,
if we try to run too slowly, the next workload has to run longer. Since
there is a hysteresis in the power graph, below a certain frequency
running a short workload for longer consumes more energy than running it
slightly higher for less time. The exact balance point is unknown
beforehand, but measurements with 30fps media playback indicate that RPe
is a better choice.
Reported-by: Edward Baker <edward.baker@intel.com>
Tested-by: Edward Baker <edward.baker@intel.com>
Fixes: 043cd2d14e ("drm/i915/gt: Leave rps->cur_freq on unpark")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201124183521.28623-1-chris@chris-wilson.co.uk
idr_init() uses base 0 which is an invalid identifier. The new function
idr_init_base allows IDR to set the ID lookup from base 1. This avoids
all lookups that otherwise starts from 0 since 0 is always unused.
References: commit 6ce711f275 ("idr: Make 1-based IDRs more efficient")
Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201104150339.GA68663@localhost
As we use a shmemfs file to hold the context state, when not in use it
may be swapped out, such as across suspend. Since we wrote into the
shmemfs without marking the pages as dirty, the contents may be dropped
instead of being written back to swap. On re-using the shmemfs file,
such as creating a new context after resume, the contents of that file
were likely garbage and so the new context could then hang the GPU.
Simply mark the page as being written when copying into the shmemfs
file, and it the new contents will be retained across swapout.
Fixes: be1cb55a07 ("drm/i915/gt: Keep a no-frills swappable copy of the default context state")
Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Venkata Ramana Nayana <venkata.ramana.nayana@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v5.8+
Link: https://patchwork.freedesktop.org/patch/msgid/20201127120718.454037-161-matthew.auld@intel.com
We checked the table size against a hardcoded number of entries, and
that number was excluding the special mocs registers at the end.
Fixes: 977933b5da ("drm/i915/gt: Program mocs:63 for cache eviction on gen9")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.3+
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127102540.13117-1-chris@chris-wilson.co.uk
If while we are cancelling the breadcrumb signaling, we find that the
request is already completed, move it to the irq signaler and let it be
signaled.
v2: Tweak reference counting so that we only acquire a new reference on
adding to a signal list, as opposed to a hidden i915_request_put of the
caller's reference.
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/20201126140407.31952-5-chris@chris-wilson.co.uk
Allow a brief period for continued access to a dead intel_context by
deferring the release of the struct until after an RCU grace period.
As we are using a dedicated slab cache for the contexts, we can defer
the release of the slab pages via RCU, with the caveat that individual
structs may be reused from the freelist within an RCU grace period. To
handle that, we have to avoid clearing members of the zombie struct.
This is required for a later patch to handle locking around virtual
requests in the signaler, as those requests may want to move between
engines and be destroyed while we are holding b->irq_lock on a physical
engine.
v2: Drop mutex_reinit(), if we never mark the mutex as destroyed we
don't need to reset the debug code, at the loss of having the mutex
debug code spot us attempting to destroy a locked mutex.
v3: As the intended use will remain strongly referenced counted, with
very little inflight access across reuse, drop the ctor.
v4: Drop the unrequired change to remove the temporary reference around
dropping the active context, and add back some more missing ctor
operations.
v5: The ctor is back. Tvrtko spotted that ce->signal_lock [introduced
later] maybe accessed under RCU and so needs special care not to be
reinitialised.
v6: Don't mix SLAB_TYPESAFE_BY_RCU and RCU list iteration.
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/20201126140407.31952-3-chris@chris-wilson.co.uk
Pull the repeated check for the last active request being completed to a
single spot, when deciding whether or not execlist preemption is
required.
In doing so, we remove the tasklet kick, introduced with the completion
checks in commit 35f3fd8182 ("drm/i915/execlists: Workaround switching
back to a completed context"), if we find the request was completed but
have not yet seen the corresponding CS event. This was devolving into a
busy spin of the tasklet while we waited for the event as the delivery
was not as instantaneous as expected. Under load this is sufficient to
exhaust the tasklet softirq timeslice, and force ksoftirqd. Quite
noticeable overhead for no apparent improvement in latency.
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/20201126140407.31952-2-chris@chris-wilson.co.uk
Since the introduction of preempt-to-busy, requests can complete in the
background, even while they are not on the engine->active.requests list.
As such, the engine->active.request list itself is not in strict
retirement order, and we have to scan the entire list while unwinding to
not miss any. However, if the request is completed we currently leave it
on the list [until retirement], but we could just as simply remove it
and stop treating it as active. We would only have to then traverse it
once while unwinding in quick succession.
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/20201126140407.31952-1-chris@chris-wilson.co.uk
Ville noticed that the last mocs entry is used unconditionally by the HW
when it performs cache evictions, and noted that while the value is not
meant to be writable by the driver, we should program it to a reasonable
value nevertheless.
As it turns out, we can change the value of mocs:63 and the value we
were programming into it would cause hard hangs in conjunction with
atomic operations.
v2: Add details from bspec about how it is used by HW
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2707
Fixes: 3bbaba0cea ("drm/i915: Added Programming of the MOCS")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: <stable@vger.kernel.org> # v4.3+
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201126140841.1982-1-chris@chris-wilson.co.uk
CT event handler is called under the gt->irq_lock from the interrupt
handling paths so make it the same from the init path. I don't think this
mismatch caused any functional issue but we need to wean the code of the
global i915->irq_lock.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120095636.1987395-2-tvrtko.ursulin@linux.intel.com
Guc->mmio_msg is set under the guc->irq_lock in guc_get_mmio_msg so it
should be consumed under the same lock from guc_handle_mmio_msg.
I am not sure if the overall flow here makes complete sense but at least
the correct lock is now used.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120095636.1987395-1-tvrtko.ursulin@linux.intel.com
Since preempt-to-busy, we may unsubmit a request while it is still on
the HW and completes asynchronously. That means it may be retired and in
the process destroy the virtual engine (as the user has closed their
context), but that engine may still be holding onto the unsubmitted
compelted request. Therefore we need to potentially cleanup the old
request on destroying the virtual engine. We also have to keep the
virtual_engine alive until after the sibling's execlists_dequeue() have
finished peeking into the virtual engines, for which we serialise with
RCU.
v2: Be paranoid and flush the tasklet as well.
v3: And flush the tasklet before the engines, as the tasklet may
re-attach an rb_node after our removal from the siblings.
Fixes: 6d06779e86 ("drm/i915: Load balancing across a virtual engine")
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/20201123113717.20500-4-chris@chris-wilson.co.uk
We currently want to keep the interrupt enabled until the interrupt after
which we have no more work to do. This heuristic was broken by us
kicking the irq-work on adding a completed request without attaching a
signaler -- hence it appearing to the irq-worker that an interrupt had
fired when we were idle.
Fixes: 2854d86632 ("drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbs")
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/20201123113717.20500-3-chris@chris-wilson.co.uk
Move the register slow register write and readback from out of the
critical path for execlists submission and delay it until the following
worker, shaving off around 200us. Note that the same signal_irq_work() is
allowed to run concurrently on each CPU (but it will only be queued once,
once running though it can be requeued and reexecuted) so we have to
remember to lock the global interactions as we cannot rely on the
signal_irq_work() itself providing the serialisation (in constrast to a
tasklet).
By pushing the arm/disarm into the central signaling worker we can close
the race for disarming the interrupt (and dropping its associated
GT wakeref) on parking the engine. If we loose the race, that GT wakeref
may be held indefinitely, preventing the machine from sleeping while
the GPU is ostensibly idle.
v2: Move the self-arming parking of the signal_irq_work to a flush of
the irq-work from intel_breadcrumbs_park().
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2271
Fixes: e23005604b ("drm/i915/gt: Hold context/request reference while breadcrumbs are active")
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/20201123113717.20500-1-chris@chris-wilson.co.uk
The old IPS interface did not match the RPS interface that we tried to
plug it into (bool vs int return). Once repaired, our minimal
selftesting is finally happy!
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/20201121190352.15996-1-chris@chris-wilson.co.uk
If we run out of ring space, or exceed the desired runtime, we wish to
stop the subtest. Put these checks together, so that we always keep the
requests flushed on completion.
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/20201120140314.24749-3-chris@chris-wilson.co.uk
We print out the "logical" context support before we discover whether or
not the engines have logical contexts. No one, except Tvrtko, seems to
have noticed the error, so the debug message must not be useful to
anyone.
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/20201120140314.24749-1-chris@chris-wilson.co.uk
Chris Wilson
Lucas De Marchi
Colin Ian King
Swathi Dhanavanthri
Dan Carpenter
Tvrtko Ursulin
Venkata Sandeep Dhanalakota
Matthew Auld
Deepak R Varma
Venkata Ramana Nayana