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path: root/drivers/gpu/drm/i915/gt/intel_lrc.c
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2021-06-05drm/i915/gt: replace IS_GEN and friends with GRAPHICS_VERLucas De Marchi
This was done by the following semantic patch: @@ expression i915; @@ - INTEL_GEN(i915) + GRAPHICS_VER(i915) @@ expression i915; expression E; @@ - INTEL_GEN(i915) >= E + GRAPHICS_VER(i915) >= E @@ expression dev_priv; expression E; @@ - !IS_GEN(dev_priv, E) + GRAPHICS_VER(dev_priv) != E @@ expression dev_priv; expression E; @@ - IS_GEN(dev_priv, E) + GRAPHICS_VER(dev_priv) == E @@ expression dev_priv; expression from, until; @@ - IS_GEN_RANGE(dev_priv, from, until) + IS_GRAPHICS_VER(dev_priv, from, until) @def@ expression E; identifier id =~ "^gen$"; @@ - id = GRAPHICS_VER(E) + ver = GRAPHICS_VER(E) @@ identifier def.id; @@ - id + ver It also takes care of renaming the variable we assign to GRAPHICS_VER() so to use "ver" rather than "gen". Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210605155356.4183026-2-lucas.demarchi@intel.com
2021-04-27drm/i915: Update the helper to set correct mappingVenkata Sandeep Dhanalakota
Determine the possible coherent map type based on object location, and if target has llc or if user requires an always coherent mapping. Cc: Matthew Auld <matthew.auld@intel.com> Cc: CQ Tang <cq.tang@intel.com> Suggested-by: Michal Wajdeczko <michal.wajdeczko@intel.com> Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com> Signed-off-by: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210427085417.120246-2-matthew.auld@intel.com
2021-04-08Merge tag 'drm-intel-gt-next-2021-04-06' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-intel into drm-next Driver Changes: - Prepare for local/device memory support on DG1 by starting to use it for kernel internal allocations: context, ring and engine scratch (Matt A, CQ, Abdiel, Imre) - Sandybridge fix to avoid hard hang on ring resume (Chris) - Limit imported dma-buf size to int32 (Matt A) - Double check heartbeat timeout before resetting (Chris) - Use new tasklet API for execution list (Emil) - Fix SPDX checkpats warnings (Chris) - Fixes for various checkpatch warnings (Chris) - Selftest improvements (Chris) - Move the defer_request waiter active assertion to correct spot (Chris) - Make local-memory probing a GT operation (Matt, Tvrtko) - Protect against request freeing during cancellation on wedging (Chris) - Retire unexpected starting state error dumping (Chris) - Distinction of memory regions in debugging (Zbigniew) - Always flush the submission queue on checking for idle (Chris) - Consolidate 2big error check to helper (Matt) - Decrease number of subplatform bits (Tvrtko) - Remove unused internal request priority levels (Chris) - Document the unused internal header bits in buddy allocator (Matt) - Cleanup the region class/instance encoding (Matt) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YGxksaZGXHnFxlwg@jlahtine-mobl.ger.corp.intel.com
2021-03-24drm/i915: allocate context from LMEMMatthew Auld
Prefer allocating the context from LMEM on dgfx. Based on a patch from Michel Thierry. v2: flatten the chain 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/20210127131417.393872-6-matthew.auld@intel.com Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2021-03-24drm/i915: Make lrc_init_wa_ctx compatible with ww locking, v3.Maarten Lankhorst
Make creation separate from pinning, in order to take the lock only once, and pin the mapping with the lock held. Changes since v1: - Rebase on top of upstream changes. Changes since v2: - Fully clear wa_ctx on error. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-27-maarten.lankhorst@linux.intel.com
2021-01-14drm/i915/gt: Prune inlinesChris Wilson
Remove all the manual inlines from non-critical sections in gt/ add/remove: 2/0 grow/shrink: 0/3 up/down: 762/-1473 (-711) Function old new delta mi_set_context.isra - 602 +602 write_dma_entry - 160 +160 __set_pd_entry 214 69 -145 clear_pd_entry 190 42 -148 ring_request_alloc 2021 841 -1180 Total: Before=1605086, After=1604375, chg -0.04% Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210113152224.29794-1-chris@chris-wilson.co.uk
2021-01-09drm/i915/gt: Remove unused function 'dword_in_page'Chris Wilson
>> drivers/gpu/drm/i915/gt/intel_lrc.c:17:28: error: unused function 'dword_in_page' [-Werror,-Wunused-function] static inline unsigned int dword_in_page(void *addr) Reported-by: kernel test robot <lkp@intel.com> 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/20210109163455.28466-1-chris@chris-wilson.co.uk
2021-01-09drm/i915/gt: Exercise lrc_wa_ctx initialisation failureChris Wilson
Inject a fault into lrc_init_wa_ctx() to ensure that we can tolerate a failure to construct the workarounds. v2: Avoid mentioning an error for fault-injection, other CI will complain about the dmesg spam. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matt Roper <matthew.d.roper@intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210109114453.27798-1-chris@chris-wilson.co.uk
2021-01-08drm/i915/gt: Prevent use of engine->wa_ctx after errorChris Wilson
On error we unpin and free the wa_ctx.vma, but do not clear any of the derived flags. During lrc_init, we look at the flags and attempt to dereference the wa_ctx.vma if they are set. To protect the error path where we try to limp along without the wa_ctx, make sure we clear those flags! Reported-by: Matt Roper <matthew.d.roper@intel.com> Fixes: 604a8f6f1e33 ("drm/i915/lrc: Only enable per-context and per-bb buffers if set") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matt Roper <matthew.d.roper@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: <stable@vger.kernel.org> # v4.15+ Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210108204026.20682-1-chris@chris-wilson.co.uk
2021-01-01drm/i915: Populate logical context during first pin.Maarten Lankhorst
This allows us to remove pin_map from state allocation, which saves us a few retry loops. We won't need this until first pin, anyway. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20201231170405.22843-1-chris@chris-wilson.co.uk
2020-12-22drm/i915/gt: Track all timelines created using the HWSPChris Wilson
We assume that the contents of the HWSP are lost across suspend, and so upon resume we must restore critical values such as the timeline seqno. Keep track of every timeline allocated that uses the HWSP as its storage and so we can then reset all seqno values by walking that list. 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/20201222104242.10993-1-chris@chris-wilson.co.uk
2020-12-21drm/i915/gt: Split logical ring contexts from execlist submissionChris Wilson
Split the definition, construction and updating of the Logical Ring Context from the execlist submission interface. The LRC is used by the HW, irrespective of our different submission backends. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201219020343.22681-1-chris@chris-wilson.co.uk
2020-12-09drm/i915/gt: Rename lrc.c to execlists_submission.cChris Wilson
We want to separate the utility functions for controlling the logical ring context from the execlists submission mechanism (which is an overgrown scheduler). This is similar to Daniele's work to split up the files, but being selfish I wanted to base it after my own changes to intel_lrc.c petered out. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201209233618.4287-2-chris@chris-wilson.co.uk
2020-12-04drm/i915/gt: Clear the execlists timers upon resetChris Wilson
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
2020-12-04drm/i915/gt: Cancel the preemption timeout on responding to itChris Wilson
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: 3a7a92aba8fb ("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
2020-12-04drm/i915/gt: Ignore repeated attempts to suspend request flow across resetChris Wilson
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: 32ff621fd744 ("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
2020-11-26drm/i915/gt: Check for a completed last request onceChris Wilson
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 35f3fd8182ba ("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
2020-11-26drm/i915/gt: Decouple completed requests on unwindChris Wilson
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
2020-11-23drm/i915/gt: Free stale request on destroying the virtual engineChris Wilson
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: 6d06779e8672 ("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
2020-11-19drm/i915: Lift waiter/signaler iteratorsChris Wilson
Lift the list iteration defines for traversing the signaler/waiter lists into i915_scheduler.h for reuse. 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/20201119165616.10834-5-chris@chris-wilson.co.uk
2020-11-19drm/i915/gt: Update request status flags for debug pretty-printerChris Wilson
We plan to expand upon the number of available statuses for when we pretty-print the requests along the timelines, and so need a new set of flags. We have settled upon: Unready [U] - initial status after being submitted, the request is not ready for execution as it is waiting for external fences Ready [R] - all fences the request was waiting on have been signaled, and the request is now ready for execution and will be in a backend queue - a ready request may still need to wait on semaphores [internal fences] Ready/virtual [V] - same as ready, but queued over multiple backends Executing [E] - the request has been transferred from the backend queue and submitted for execution on HW - a completed request may still be regarded as executing, its status may not be updated until it is retired and removed from the lists 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/20201119165616.10834-3-chris@chris-wilson.co.uk
2020-11-19drm/i915: Lift i915_request_show()Chris Wilson
Extract i915_request_show for reuse in other request chain pretty printers. For a bonus point, quietly change the seqno format from %llx to %lld to match everywhere else. 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/20201119165616.10834-2-chris@chris-wilson.co.uk
2020-11-18drm/i915/gt: Remember to free the virtual breadcrumbsChris Wilson
Since we allocate some breadcrumbs for the virtual engine, and the virtual engine has a custom destructor, we also need to free the breadcrumbs after use. Fixes: b3786b29379c ("drm/i915/gt: Distinguish the virtual breadcrumbs from the irq breadcrumbs") 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/20201118133839.1783-1-chris@chris-wilson.co.uk
2020-11-17drm/i915/gt: Ignore dt==0 for reporting underflowsChris Wilson
The presumption was that some time would always elapse between recording the start and the finish of a context switch. This turns out to be a regular occurrence and emitting a debug statement superfluous. 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/20201117113103.21480-4-chris@chris-wilson.co.uk
2020-11-09drm/i915: Improve record of hung engines in error stateTvrtko Ursulin
Between events which trigger engine and GPU resets and capturing the error state we lose information on which engine triggered the reset. Improve this by passing in the hung engine mask down to error capture. Result is that the list of engines in user visible "GPU HANG: ecode <gen>:<engines>:<ecode>, <process>" is now a list of hanging and not just active engines. Most importantly the displayed process is now the one which was actually hung. v2: * Stub prototype. (Chris) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20201104134743.916027-1-tvrtko.ursulin@linux.intel.com
2020-11-03drm/i915/gt: Flush xcs before tgl breadcrumbsChris Wilson
In a simple test case that writes to scratch and then busy-waits for the batch to be signaled, we observe that the signal is before the write is posted. That is bad news. Splitting the flush + write_dword into two separate flush_dw prevents the issue from being reproduced, we can presume the post-sync op is not so post-sync. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/216 Testcase: igt/gem_exec_fence/parallel Testcase: igt/i915_selftest/live/gt_timelines Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: stable@vger.kernel.org Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201102221057.29626-2-chris@chris-wilson.co.uk
2020-10-23drm/i915/gt: Use the local HWSP offset during submissionChris Wilson
We wrap the timeline on construction of the next request, but there may still be requests in flight that have not yet finalized the breadcrumb. (The breadcrumb is delayed as we need engine-local offsets, and for the virtual engine that is not known until execution.) As such, by the time we write to the timeline's HWSP offset it may have changed, and we should use the value we preserved in the request instead. Though the window is small and infrequent (at full flow we can expect a timeline's seqno to wrap once every 30 minutes), the impact of writing the old seqno into the new HWSP is severe: the old requests are never completed, and the new requests are completed before they are even submitted. Fixes: ebece7539242 ("drm/i915: Keep timeline HWSP allocated until idle across the system") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: <stable@vger.kernel.org> # v5.2+ Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201022064127.10159-1-chris@chris-wilson.co.uk
2020-10-16drm/i915/gt: Confirm the context survives executionChris Wilson
Repeat our sanitychecks from before execution to after execution. One expects that if we were to see these, the gpu would already be on fire, but the timing may be informative. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201015190816.31763-1-chris@chris-wilson.co.uk
2020-10-16drm/i915/gt: Undo forced context restores after trivial preemptionsChris Wilson
We may try to preempt the currently executing request, only to find that after unravelling all the dependencies that the original executing context is still the earliest in the topological sort and re-submitted back to HW (if we do detect some change in the ELSP that requires re-submission). However, due to the way we check for wrap-around during the unravelling, we mark any context that has been submitted just once (i.e. with the rq->wa_tail set, but the ring->tail earlier) as potentially wrapping and requiring a forced restore on resubmission. This was expected to be not a problem, as it was anticipated that most unwinding for preemption would result in a context switch and the few that did not would be lost in the noise. It did not take long for someone to find one particular workload where the cost of those extra context restores was measurable. However, since we know the wa_tail is of fixed size, and we know that a request must be larger than the wa_tail itself, we can safely maintain the check for request wrapping and check against a slightly future point in the ring that includes an expected wa_tail. (That is if the ring->tail is already set to rq->wa_tail, including another 8 bytes in the check does not invalidate the incremental wrap detection.) Fixes: 8ab3a3812aa9 ("drm/i915/gt: Incrementally check for rewinding") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Bruce Chang <yu.bruce.chang@intel.com> Cc: Ramalingam C <ramalingam.c@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: <stable@vger.kernel.org> # v5.4+ Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201002083425.4605-1-chris@chris-wilson.co.uk
2020-10-16drm/i915/gt: Delay execlist processing for tglChris Wilson
When running gem_exec_nop, it floods the system with many requests (with the goal of userspace submitting faster than the HW can process a single empty batch). This causes the driver to continually resubmit new requests onto the end of an active context, a flood of lite-restore preemptions. If we time this just right, Tigerlake hangs. Inserting a small delay between the processing of CS events and submitting the next context, prevents the hang. Naturally it does not occur with debugging enabled. The suspicion then is that this is related to the issues with the CS event buffer, and inserting an mmio read of the CS pointer status appears to be very successful in preventing the hang. Other registers, or uncached reads, or plain mb, do not prevent the hang, suggesting that register is key -- but that the hang can be prevented by a simple udelay, suggests it is just a timing issue like that encountered by commit 233c1ae3c83f ("drm/i915/gt: Wait for CSB entries on Tigerlake"). Also note that the hang is not prevented by applying CTX_DESC_FORCE_RESTORE, or by inserting a delay on the GPU between requests. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Bruce Chang <yu.bruce.chang@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: stable@vger.kernel.org Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201015195023.32346-1-chris@chris-wilson.co.uk
2020-09-30drm/i915/gt: Signal cancelled requestsChris Wilson
After marking the requests on an engine as cancelled upon wedging, send any signals for their completions. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200930163253.2789-1-chris@chris-wilson.co.uk
2020-09-18drm/i915/gt: Remove defunct intel_virtual_engine_get_sibling()Chris Wilson
As the last user was eliminated in commit e21fecdcde40 ("drm/i915/gt: Distinguish the virtual breadcrumbs from the irq breadcrumbs"), we can remove the function. One less implementation detail creeping beyond its scope. 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/20200826132811.17577-16-chris@chris-wilson.co.uk
2020-09-15drm/i915/gt: Use a mmio read of the CSB in case of failureChris Wilson
If we find the GPU didn't update the CSB within 50us, we currently fail and eventually reset the GPU. Lets report the value from the mmio space as a last resort, it may just stave off an unnecessary GPU reset. References: HSDES#22011327657 Suggested-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200915134923.30088-4-chris@chris-wilson.co.uk
2020-09-15drm/i915/gt: Apply the CSB w/a for allChris Wilson
Since we expect to inline the csb_parse() routines, the w/a for the stale CSB data on Tigerlake will be pulled into process_csb(), and so we might as well simply reuse the logic for all, and so will hopefully avoid any strange behaviour on Icelake that was not covered by our previous w/a. References: d8f505311717 ("drm/i915/icl: Forcibly evict stale csb entries") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: Bruce Chang <yu.bruce.chang@intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200915134923.30088-3-chris@chris-wilson.co.uk
2020-09-15drm/i915/gt: Wait for CSB entries on TigerlakeChris Wilson
On Tigerlake, we are seeing a repeat of commit d8f505311717 ("drm/i915/icl: Forcibly evict stale csb entries") where, presumably, due to a missing Global Observation Point synchronisation, the write pointer of the CSB ringbuffer is updated _prior_ to the contents of the ringbuffer. That is we see the GPU report more context-switch entries for us to parse, but those entries have not been written, leading us to process stale events, and eventually report a hung GPU. However, this effect appears to be much more severe than we previously saw on Icelake (though it might be best if we try the same approach there as well and measure), and Bruce suggested the good idea of resetting the CSB entry after use so that we can detect when it has been updated by the GPU. By instrumenting how long that may be, we can set a reliable upper bound for how long we should wait for: 513 late, avg of 61 retries (590 ns), max of 1061 retries (10099 ns) Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2045 References: d8f505311717 ("drm/i915/icl: Forcibly evict stale csb entries") References: HSDES#22011327657, HSDES#1508287568 Suggested-by: Bruce Chang <yu.bruce.chang@intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Bruce Chang <yu.bruce.chang@intel.com> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Cc: stable@vger.kernel.org # v5.4 Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200915134923.30088-2-chris@chris-wilson.co.uk
2020-09-15drm/i915/gt: Widen CSB pointer to u64 for the parsersChris Wilson
A CSB entry is 64b, and it is simpler for us to treat it as an array of 64b entries than as an array of pairs of 32b entries. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200915134923.30088-1-chris@chris-wilson.co.uk
2020-09-07drm/i915: Be wary of data races when reading the active execlistsChris Wilson
To implement preempt-to-busy (and so efficient timeslicing and best utilization of the hardware submission ports) we let the GPU run asynchronously in respect to the ELSP submission queue. This created challenges in keeping and accessing the driver state mirroring the asynchronous GPU execution. The latest occurence of this was spotted by KCSAN: [ 1413.563200] BUG: KCSAN: data-race in __await_execution+0x217/0x370 [i915] [ 1413.563221] [ 1413.563236] race at unknown origin, with read to 0xffff88885bb6c478 of 8 bytes by task 9654 on cpu 1: [ 1413.563548] __await_execution+0x217/0x370 [i915] [ 1413.563891] i915_request_await_dma_fence+0x4eb/0x6a0 [i915] [ 1413.564235] i915_request_await_object+0x421/0x490 [i915] [ 1413.564577] i915_gem_do_execbuffer+0x29b7/0x3c40 [i915] [ 1413.564967] i915_gem_execbuffer2_ioctl+0x22f/0x5c0 [i915] [ 1413.564998] drm_ioctl_kernel+0x156/0x1b0 [ 1413.565022] drm_ioctl+0x2ff/0x480 [ 1413.565046] __x64_sys_ioctl+0x87/0xd0 [ 1413.565069] do_syscall_64+0x4d/0x80 [ 1413.565094] entry_SYSCALL_64_after_hwframe+0x44/0xa9 To complicate matters, we have to both avoid the read tearing of *active and avoid any write tearing as perform the pending[] -> inflight[] promotion of the execlists. This is because we cannot rely on the memcpy doing u64 aligned copies on all kernels/platforms and so we opt to open-code it with explicit WRITE_ONCE annotations to satisfy KCSAN. v2: When in doubt, write the same comment again. v3: Expanded commit message. Fixes: b55230e5e800 ("drm/i915: Check for awaits on still currently executing requests") 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/20200716142207.13003-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] [Joonas: Added expanded commit message from Tvrtko and Chris] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Make sure execbuffer always passes ww state to i915_vma_pin.Maarten Lankhorst
As a preparation step for full object locking and wait/wound handling during pin and object mapping, ensure that we always pass the ww context in i915_gem_execbuffer.c to i915_vma_pin, use lockdep to ensure this happens. This also requires changing the order of eb_parse slightly, to ensure we pass ww at a point where we could still handle -EDEADLK safely. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-15-maarten.lankhorst@linux.intel.com Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Rework intel_context pinning to do everything outside of pin_mutexMaarten Lankhorst
Instead of doing everything inside of pin_mutex, we move all pinning outside. Because i915_active has its own reference counting and pinning is also having the same issues vs mutexes, we make sure everything is pinned first, so the pinning in i915_active only needs to bump refcounts. This allows us to take pin refcounts correctly all the time. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-14-maarten.lankhorst@linux.intel.com Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Distinguish the virtual breadcrumbs from the irq breadcrumbsChris Wilson
On the virtual engines, we only use the intel_breadcrumbs for tracking signaling of stale breadcrumbs from the irq_workers. They do not have any associated interrupt handling, active requests are passed to a physical engine and associated breadcrumb interrupt handler. This causes issues for us as we need to ensure that we do not actually try and enable interrupts and the powermanagement required for them on the virtual engine, as they will never be disabled. Instead, let's specify the physical engine used for interrupt handler on a particular breadcrumb. v2: Drop b->irq_armed = true mocking for no interrupt HW Fixes: 4fe6abb8f513 ("drm/i915/gt: Ignore irq enabling on the virtual engines") 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/20200731154834.8378-4-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Only transfer the virtual context to the new engine if activeChris Wilson
One more complication of preempt-to-busy with respect to the virtual engine is that we may have retired the last request along the virtual engine at the same time as preparing to submit the completed request to a new engine. That submit will be shortcircuited, but not before we have updated the context with the new register offsets and marked the virtual engine as bound to the new engine (by calling swap on ve->siblings[]). As we may have just retired the completed request, we may also be in the middle of calling virtual_context_exit() to turn off the power management associated with the virtual engine, and that in turn walks the ve->siblings[]. If we happen to call swap() on the array as we walk, we will call intel_engine_pm_put() twice on the same engine. In this patch, we prevent this by only updating the bound engine after a successful submission which weeds out the already completed requests. Alternatively, we could walk a non-volatile array for the pm, such as using the engine->mask. The small advantage to performing the update after the submit is that we then only have to do a swap for active requests. Fixes: 22b7a426bbe1 ("drm/i915/execlists: Preempt-to-busy") References: 6d06779e8672 ("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> Cc: "Nayana, Venkata Ramana" <venkata.ramana.nayana@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731154834.8378-3-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Replace intel_engine_transfer_stale_breadcrumbsChris Wilson
After staring at the breadcrumb enabling/cancellation and coming to the conclusion that the cause of the mysterious stale breadcrumbs must the act of submitting a completed requests, we can then redirect those completed requests onto a dedicated signaled_list at the time of construction and so eliminate intel_engine_transfer_stale_breadcrumbs(). 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/20200731154834.8378-2-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915: Remove requirement for holding i915_request.lock for breadcrumbsChris Wilson
Since the breadcrumb enabling/cancelling itself is serialised by the breadcrumbs.irq_lock, with a bit of care we can remove the outer serialisation with i915_request.lock for concurrent dma_fence_enable_signaling(). This has the important side-effect of eliminating the nested i915_request.lock within request submission. The challenge in serialisation is around the unsubmission where we take an active request that wants a breadcrumb on the signaling engine and put it to sleep. We do not want a concurrent dma_fence_enable_signaling() to attach a breadcrumb as we unsubmit, so we must mark the request as no longer active before serialising with the concurrent enable-signaling. On retire, we serialise with the concurrent enable-signaling, but instead of clearing ACTIVE, we mark it as SIGNALED. 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/20200731154834.8378-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> [Joonas: Rebased and reordered into drm-intel-gt-next branch] Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Support multiple pinned timelinesChris Wilson
We may need to allocate more than one pinned context/timeline for each engine which can utilise the per-engine HWSP, so we need to give each a different offset within it. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200730183906.25422-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07drm/i915/gt: Disable preparser around xcs invalidations on tglChris Wilson
Unlike rcs where we have conclusive evidence from our selftesting that disabling the preparser before performing the TLB invalidate and relocations does impact upon the GPU execution, the evidence for the same requirement on xcs is much more circumstantial. Let's apply the preparser disable between batches as we invalidate the TLB as a dose of healthy paranoia, just in case. References: https://gitlab.freedesktop.org/drm/intel/-/issues/2169 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200728152110.830-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-08-28Merge tag 'drm-intel-next-2020-08-24-1' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-intel into drm-next UAPI Changes: - Introduce a mechanism to extend execbuf2 (Lionel) - Add syncobj timeline support (Lionel) Driver Changes: - Limit stolen mem usage on the compressed frame buffer (Ville) - Some clean-up around display's cdclk (Ville) - Some DDI changes for better DP link training according to spec (Imre) - Provide the perf pmu.module (Chris) - Remove dobious Valleyview PCI IDs (Alexei) - Add new display power saving feature for gen12+ called HOBL (Jose) - Move SKL's clock gating w/a to skl_init_clock_gating() (Ville) - Rocket Lake display additions (Matt) - Selftest: temporarily downgrade on severity of frequency scaling tests (Chris) - Introduce a new display workaround for fixing FLR related issues on new PCH. (Jose) - Temporarily disable FBC on TGL. It was the culprit of random underruns. (Uma). - Copy default modparams to mock i915_device (Chris) - Add compiler paranoia for checking HWSP values (Chris) - Remove useless gen check before calling intel_rps_boost (Chris) - Fix a null pointer dereference (Chris) - Add a couple of missing i915_active_fini() (Chris) - Update TGL display power's bw_buddy table according to update spec (Matt) - Fix couple wrong return values (Tianjia) - Selftest: Avoid passing random 0 into ilog2 (George) - Many Tiger Lake display fixes and improvements for Type-C and DP compliance (Imre, Jose) - Start the addition of PSR2 selective fetch (Jose) - Update a few DMC and HuC firmware versions (Jose) - Add gen11+ w/a to fix underuns (Matt) - Fix cmd parser desc matching with mask (Mika) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200826232733.GA129053@intel.com
2020-08-17drm/i915/kbl: Fix revision ID checksMatt Roper
We usually assume that increasing PCI device revision ID's translates to newer steppings; macros like IS_KBL_REVID() that we use rely on this behavior. Unfortunately this turns out to not be true on KBL; the newer device 2 revision ID's sometimes go backward to older steppings. The situation is further complicated by different GT and display steppings associated with each revision ID. Let's work around this by providing a table to map the revision ID to specific GT and display steppings, and then perform our comparisons on the mapped values. v2: - Move the kbl_revids[] array to intel_workarounds.c to avoid compiler warnings about an unused variable in files that don't call the macros (kernel test robot). Bspec: 18329 Signed-off-by: Matt Roper <matthew.d.roper@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200811032105.2819370-1-matthew.d.roper@intel.com Reviewed-by: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-08-05Merge tag 'drm-next-2020-08-06' of git://anongit.freedesktop.org/drm/drmLinus Torvalds
Pull drm updates from Dave Airlie: "New xilinx displayport driver, AMD support for two new GPUs (more header files), i915 initial support for RocketLake and some work on their DG1 (discrete chip). The core also grew some lockdep annotations to try and constrain what drivers do with dma-fences, and added some documentation on why the idea of indefinite fences doesn't work. The long list is below. I do have some fixes trees outstanding, but I'll follow up with those later. core: - add user def flag to cmd line modes - dma_fence_wait added might_sleep - dma-fence lockdep annotations - indefinite fences are bad documentation - gem CMA functions used in more drivers - struct mutex removal - more drm_ debug macro usage - set/drop master api fixes - fix for drm/mm hole size comparison - drm/mm remove invalid entry optimization - optimise drm/mm hole handling - VRR debugfs added - uncompressed AFBC modifier support - multiple display id blocks in EDID - multiple driver sg handling fixes - __drm_atomic_helper_crtc_reset in all drivers - managed vram helpers ttm: - ttm_mem_reg handling cleanup - remove bo offset field - drop CMA memtype flag - drop mappable flag xilinx: - New Xilinx ZynqMP DisplayPort Subsystem driver nouveau: - add CRC support - start using NVIDIA published class header files - convert all push buffer emission to new macros - Proper push buffer space management for EVO/NVD channels. - firmware loading fixes - 2MiB system memory pages support on Pascal and newer vkms: - larger cursor support i915: - Rocketlake platform enablement - Early DG1 enablement - Numerous GEM refactorings - DP MST fixes - FBC, PSR, Cursor, Color, Gamma fixes - TGL, RKL, EHL workaround updates - TGL 8K display support fixes - SDVO/HDMI/DVI fixes amdgpu: - Initial support for Sienna Cichlid GPU - Initial support for Navy Flounder GPU - SI UVD/VCE support - expose rotation property - Add support for unique id on Arcturus - Enable runtime PM on vega10 boards that support BACO - Skip BAR resizing if the bios already did id - Major swSMU code cleanup - Fixes for DCN bandwidth calculations amdkfd: - Track SDMA usage per process - SMI events interface radeon: - Default to on chip GART for AGP boards on all arches - Runtime PM reference count fixes msm: - headers regenerated causing churn - a650/a640 display and GPU enablement - dpu dither support for 6bpc panels - dpu cursor fix - dsi/mdp5 enablement for sdm630/sdm636/sdm66 tegra: - video capture prep support - reflection support mediatek: - convert mtk_dsi to bridge API meson: - FBC support sun4i: - iommu support rockchip: - register locking fix - per-pixel alpha support PX30 VOP mgag200: - ported to simple and shmem helpers - device init cleanups - use managed pci functions - dropped hw cursor support ast: - use managed pci functions - use managed VRAM helpers - rework cursor support malidp: - dev_groups support hibmc: - refactor hibmc_drv_vdac: vc4: - create TXP CRTC imx: - error path fixes and cleanups etnaviv: - clock handling and error handling cleanups - use pin_user_pages" * tag 'drm-next-2020-08-06' of git://anongit.freedesktop.org/drm/drm: (1747 commits) drm/msm: use kthread_create_worker instead of kthread_run drm/msm/mdp5: Add MDP5 configuration for SDM636/660 drm/msm/dsi: Add DSI configuration for SDM660 drm/msm/mdp5: Add MDP5 configuration for SDM630 drm/msm/dsi: Add phy configuration for SDM630/636/660 drm/msm/a6xx: add A640/A650 hwcg drm/msm/a6xx: hwcg tables in gpulist drm/msm/dpu: add SM8250 to hw catalog drm/msm/dpu: add SM8150 to hw catalog drm/msm/dpu: intf timing path for displayport drm/msm/dpu: set missing flush bits for INTF_2 and INTF_3 drm/msm/dpu: don't use INTF_INPUT_CTRL feature on sdm845 drm/msm/dpu: move some sspp caps to dpu_caps drm/msm/dpu: update UBWC config for sm8150 and sm8250 drm/msm/dpu: use right setup_blend_config for sm8150 and sm8250 drm/msm/a6xx: set ubwc config for A640 and A650 drm/msm/adreno: un-open-code some packets drm/msm: sync generated headers drm/msm/a6xx: add build_bw_table for A640/A650 drm/msm/a6xx: fix crashstate capture for A650 ...
2020-08-04Merge tag 'uninit-macro-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var()
2020-07-16treewide: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>