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path: root/drivers/gpu/drm/i915/i915_active.c
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2020-10-15Merge tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drmLinus Torvalds
Pull drm updates from Dave Airlie: "Not a major amount of change, the i915 trees got split into display and gt trees to better facilitate higher level review, and there's a major refactoring of i915 GEM locking to use more core kernel concepts (like ww-mutexes). msm gets per-process pagetables, older AMD SI cards get DC support, nouveau got a bump in displayport support with common code extraction from i915. Outside of drm this contains a couple of patches for hexint moduleparams which you've acked, and a virtio common code tree that you should also get via it's regular path. New driver: - Cadence MHDP8546 DisplayPort bridge driver core: - cross-driver scatterlist cleanups - devm_drm conversions - remove drm_dev_init - devm_drm_dev_alloc conversion ttm: - lots of refactoring and cleanups bridges: - chained bridge support in more drivers panel: - misc new panels scheduler: - cleanup priority levels displayport: - refactor i915 code into helpers for nouveau i915: - split into display and GT trees - WW locking refactoring in GEM - execbuf2 extension mechanism - syncobj timeline support - GEN 12 HOBL display powersaving - Rocket Lake display additions - Disable FBC on Tigerlake - Tigerlake Type-C + DP improvements - Hotplug interrupt refactoring amdgpu: - Sienna Cichlid updates - Navy Flounder updates - DCE6 (SI) support for DC - Plane rotation enabled - TMZ state info ioctl - PCIe DPC recovery support - DC interrupt handling refactor - OLED panel fixes amdkfd: - add SMI events for thermal throttling - SMI interface events ioctl update - process eviction counters radeon: - move to dma_ for allocations - expose sclk via sysfs msm: - DSI support for sm8150/sm8250 - per-process GPU pagetable support - Displayport support mediatek: - move HDMI phy driver to PHY - convert mtk-dpi to bridge API - disable mt2701 tmds tegra: - bridge support exynos: - misc cleanups vc4: - dual display cleanups ast: - cleanups gma500: - conversion to GPIOd API hisilicon: - misc reworks ingenic: - clock handling and format improvements mcde: - DSI support mgag200: - desktop g200 support mxsfb: - i.MX7 + i.MX8M - alpha plane support panfrost: - devfreq support - amlogic SoC support ps8640: - EDID from eDP retrieval tidss: - AM65xx YUV workaround virtio: - virtio-gpu exported resources rcar-du: - R8A7742, R8A774E1 and R8A77961 support - YUV planar format fixes - non-visible plane handling - VSP device reference count fix - Kconfig fix to avoid displaying disabled options in .config" * tag 'drm-next-2020-10-15' of git://anongit.freedesktop.org/drm/drm: (1494 commits) drm/ingenic: Fix bad revert drm/amdgpu: Fix invalid number of character '{' in amdgpu_acpi_init drm/amdgpu: Remove warning for virtual_display drm/amdgpu: kfd_initialized can be static drm/amd/pm: setup APU dpm clock table in SMU HW initialization drm/amdgpu: prevent spurious warning drm/amdgpu/swsmu: fix ARC build errors drm/amd/display: Fix OPTC_DATA_FORMAT programming drm/amd/display: Don't allow pstate if no support in blank drm/panfrost: increase readl_relaxed_poll_timeout values MAINTAINERS: Update entry for st7703 driver after the rename Revert "gpu/drm: ingenic: Add option to mmap GEM buffers cached" drm/amd/display: HDMI remote sink need mode validation for Linux drm/amd/display: Change to correct unit on audio rate drm/amd/display: Avoid set zero in the requested clk drm/amdgpu: align frag_end to covered address space drm/amdgpu: fix NULL pointer dereference for Renoir drm/vmwgfx: fix regression in thp code due to ttm init refactor. drm/amdgpu/swsmu: add interrupt work handler for smu11 parts drm/amdgpu/swsmu: add interrupt work function ...
2020-09-24treewide: Make all debug_obj_descriptors constStephen Boyd
This should make it harder for the kernel to corrupt the debug object descriptor, used to call functions to fixup state and track debug objects, by moving the structure to read-only memory. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org
2020-09-07drm/i915: Reduce locking around i915_active_acquire_preallocate_barrier()Chris Wilson
As the conversion between idle-barrier and full i915_active_fence is already serialised by explicit memory barriers, we can reduce the spinlock in i915_active_acquire_preallocate_barrier() for finding an idle-barrier to reuse to an RCU read lock to ensure the fence remains valid, only taking the spinlock for the update of the rbtree itself. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-6-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: Make the stale cached active node available for any timelineChris Wilson
Rather than require the next timeline after idling to match the MRU before idling, reset the index on the node and allow it to match the first request. However, this requires cmpxchg(u64) and so is not trivial on 32b, so for compatibility we just fallback to keeping the cached node pointing to the MRU timeline. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-5-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: Keep the most recently used active-fence upon discardChris Wilson
Whenever an i915_active idles, we prune its tree of old fence slots to prevent a gradual leak should it be used to track many, many timelines. The downside is that we then have to frequently reallocate the rbtree. A compromise is that we keep the most recently used fence slot, and reuse that for the next active reference as that is the most likely timeline to be reused. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-4-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: Export a preallocate variant of i915_active_acquire()Chris Wilson
Sometimes we have to be very careful not to allocate underneath a mutex (or spinlock) and yet still want to track activity. Enter i915_active_acquire_for_context(). This raises the activity counter on i915_active prior to use and ensures that the fence-tree contains a slot for the context. v2: Refactor active_lookup() so it can be called again before/after locking to resolve contention. Since we protect the rbtree until we idle, we can do a lockfree lookup, with the caveat that if another thread performs a concurrent insertion, the rotations from the insert may cause us to not find our target. A second pass holding the treelock will find the target if it exists, or the place to perform our insertion. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-3-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: Skip taking acquire mutex for no ref->active callbackChris Wilson
If no active callback is defined for i915_active, we do not need to serialise its enabling with the mutex. We still do only want to call the debug activate once, and must still serialise with a concurrent retire. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200731085015.32368-2-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-08-17drm/i915: Fix wrong return valueTianjia Zhang
In function i915_active_acquire_preallocate_barrier(), not all paths have the return value set correctly, and in case of memory allocation failure, a negative error code should be returned. Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.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/20200802115655.25568-1-chris@chris-wilson.co.uk Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2020-04-06drm/i915: Allow asynchronous waits on the i915_active barriersChris Wilson
Allow the caller to also wait upon the barriers stored in i915_active. v2: Hook up i915_request_await_active(I915_ACTIVE_AWAIT_BARRIER) as well for completeness, and avoid the lazy GEM_BUG_ON()! v3: Pull flush_lazy_signals() under the active-ref protection as it too walks the rbtree and so we must be careful that we do not free it as we iterate. 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/20200406155840.1728-2-chris@chris-wilson.co.uk
2020-04-06drm/i915: Make exclusive awaits on i915_active optionalChris Wilson
Later use will require asynchronous waits on the active timelines, but will not utilize an async wait on the exclusive channel. Make the await on the exclusive fence explicit in the selection flags. 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/20200406155840.1728-1-chris@chris-wilson.co.uk
2020-03-30drm/i915: Wrap i915_active in a simple kreffed structChris Wilson
For conveniences of callers that just want to use an i915_active to track a wide array of concurrent timelines, wrap the base i915_active struct inside a kref. This i915_active will self-destruct after use. 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/20200327112212.16046-2-chris@chris-wilson.co.uk
2020-03-30drm/i915: Allow for different modes of interruptible i915_active_waitChris Wilson
Allow some users the discretion to not immediately return on a normal signal. Hopefully, they will opt to use TASK_KILLABLE instead. 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/20200327112212.16046-1-chris@chris-wilson.co.uk
2020-03-23drm/i915/gt: Delay release of engine-pm after last retirementChris Wilson
Keep the engine-pm awake until the next jiffie, to avoid immediate ping-pong under moderate load. (Forcing the idle barrier excerbates the moderate load, dramatically increasing the driver overhead.) On the other hand, delaying the idle-barrier slightly incurs longer rc6-off and so more power consumption. Closes: https://gitlab.freedesktop.org/drm/intel/issues/848 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/20200323092841.22240-4-chris@chris-wilson.co.uk
2020-03-11drm/i915: Extend i915_request_await_active to use all timelinesChris Wilson
Extend i915_request_await_active() to be able to asynchronously wait on all the tracked timelines simultaneously. 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/20200311092044.16353-1-chris@chris-wilson.co.uk
2020-02-28drm/i915: Skip barriers inside waitsChris Wilson
Attaching to the i915_active barrier is a two stage process, and a flush is only effective when the barrier is activation. Thus it is possible for us to see a barrier, and attempt to flush, only for our flush to have no effect. As such, before attempting to activate signaling on the fence we need to double check it is a fence! Fixes: d13a31770077 ("drm/i915: Flush idle barriers when waiting") Closes: https://gitlab.freedesktop.org/drm/intel/issues/1333 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Andi Shyti <andi.shyti@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200227085723.1961649-1-chris@chris-wilson.co.uk
2020-02-25drm/i915: Flush idle barriers when waitingChris Wilson
If we do find ourselves with an idle barrier inside our active while waiting, attempt to flush it by emitting a pulse using the kernel context. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Steve Carbonari <steven.carbonari@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200225192206.1107336-1-chris@chris-wilson.co.uk
2020-02-25drm/i915: Drop assertion that active->fence is unchangedChris Wilson
We cannot assert the fence is not yet changed as the next thread may change it prior to acquiring our lock. 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/20200225082233.274530-1-chris@chris-wilson.co.uk
2020-02-03drm/i915: Hold reference to previous active fence as we queueChris Wilson
Take a reference to the previous exclusive fence on the i915_active, as we wish to add an await to it in the caller (and so must prevent it from being freed until we have completed that task). Fixes: e3793468b466 ("drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutex") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200203094152.4150550-1-chris@chris-wilson.co.uk
2020-01-30drm/i915: Use the async worker to avoid reclaim tainting the ggtt->mutexChris Wilson
On Braswell and Broxton (also known as Valleyview and Apollolake), we need to serialise updates of the GGTT using the big stop_machine() hammer. This has the side effect of appearing to lockdep as a possible reclaim (since it uses the cpuhp mutex and that is tainted by per-cpu allocations). However, we want to use vm->mutex (including ggtt->mutex) from within the shrinker and so must avoid such possible taints. For this purpose, we introduced the asynchronous vma binding and we can apply it to the PIN_GLOBAL so long as take care to add the necessary waits for the worker afterwards. Closes: https://gitlab.freedesktop.org/drm/intel/issues/211 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/20200130181710.2030251-3-chris@chris-wilson.co.uk
2020-01-30drm/i915: Fix preallocated barrier list appendJosé Roberto de Souza
Only the first and the last nodes were being added to ref->preallocated_barriers. Renaming variables to make it more easy to read. Fixes: 841350223816 ("drm/i915/gt: Drop mutex serialisation between context pin/unpin") Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@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/20200129232345.84512-1-jose.souza@intel.com
2020-01-27drm/i915: Tighten atomicity of i915_active_acquire vs i915_active_releaseChris Wilson
As we use a mutex to serialise the first acquire (as it may be a lengthy operation), but only an atomic decrement for the release, we have to be careful in case a second thread races and completes both acquire/release as the first finishes its acquire. Thread A Thread B i915_active_acquire i915_active_acquire atomic_read() == 0 atomic_read() == 0 mutex_lock() mutex_lock() atomic_read() == 0 ref->active(); atomic_inc() mutex_unlock() atomic_read() == 1 i915_active_release atomic_dec_and_test() -> 0 ref->retire() atomic_inc() -> 1 mutex_unlock() So thread A has acquired the ref->active_count but since the ref was still active at the time, it did not initialise it. By switching the check inside the mutex to an atomic increment only if already active, we close the race. Fixes: c9ad602feabe ("drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtree") 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/20200126102346.1877661-3-chris@chris-wilson.co.uk
2020-01-17drm/i915: Satisfy smatch that a loop has at least one iterationChris Wilson
Smatch worries that the engine->mask may be 0 leading to the loop being shortcircuited leaving the next pointer unset, drivers/gpu/drm/i915/i915_active.c:667 i915_active_acquire_preallocate_barrier() error: uninitialized symbol 'next'. Assert that mask is not 0 and smatch can then verify that next must be initialised before use. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200117110603.2982286-1-chris@chris-wilson.co.uk
2020-01-06drm/i915/gt: Drop mutex serialisation between context pin/unpinChris Wilson
The last remaining reason for serialising the pin/unpin of the intel_context is to ensure that our preallocated wakerefs are not consumed too early (i.e. the unpin of the previous phase does not emit the idle barriers for this phase before we even submit). All of the other operations within the context pin/unpin are supposed to be atomic... Therefore, we can reduce the serialisation to being just on the i915_active.preallocated_barriers itself and drop the nested pin_mutex from intel_context_unpin(). Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200106114234.2529613-5-chris@chris-wilson.co.uk
2019-12-21drm/i915: Remove i915->kernel_contextChris Wilson
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
2019-12-05drm/i915: Serialise i915_active_acquire() with __active_retire()Chris Wilson
As __active_retire() does it's final atomic_dec() under the ref->tree_lock spinlock, in order to prevent ourselves from reusing the ref->cache and ref->tree as they are being destroyed, we need to serialise with the retirement during i915_active_acquire(). [ +0.000005] kernel BUG at drivers/gpu/drm/i915/i915_active.c:157! [ +0.000011] invalid opcode: 0000 [#1] SMP [ +0.000004] CPU: 7 PID: 188 Comm: kworker/u16:4 Not tainted 5.4.0-rc8-03070-gac5e57322614 #89 [ +0.000002] Hardware name: Razer Razer Blade Stealth 13 Late 2019/LY320, BIOS 1.02 09/10/2019 [ +0.000082] Workqueue: events_unbound active_work [i915] [ +0.000059] RIP: 0010:__active_retire+0x115/0x120 [i915] [ +0.000003] Code: 75 28 48 8b 3d 8c 6e 1a 00 48 89 ee e8 e4 5f a5 c0 48 8b 44 24 10 65 48 33 04 25 28 00 00 00 75 0f 48 83 c4 18 5b 5d 41 5c c3 <0f> 0b 0f 0b 0f 0b e8 a0 90 87 c0 0f 1f 44 00 00 48 8b 3d 54 6e 1a [ +0.000002] RSP: 0018:ffffb833003f7e48 EFLAGS: 00010286 [ +0.000003] RAX: ffff8d6e8d726d00 RBX: ffff8d6f9db4e840 RCX: 0000000000000000 [ +0.000001] RDX: ffffffff82605930 RSI: ffff8d6f9adc4908 RDI: ffff8d6e96cefe28 [ +0.000002] RBP: ffff8d6e96cefe00 R08: 0000000000000000 R09: ffff8d6f9ffe9a50 [ +0.000002] R10: 0000000000000048 R11: 0000000000000018 R12: ffff8d6f9adc4930 [ +0.000001] R13: ffff8d6f9e04fb00 R14: 0000000000000000 R15: ffff8d6f9adc4988 [ +0.000002] FS: 0000000000000000(0000) GS:ffff8d6f9ffc0000(0000) knlGS:0000000000000000 [ +0.000002] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000002] CR2: 000055eb5a34cf10 CR3: 000000018d609002 CR4: 0000000000760ee0 [ +0.000002] PKRU: 55555554 [ +0.000001] Call Trace: [ +0.000010] process_one_work+0x1aa/0x350 [ +0.000004] worker_thread+0x4d/0x3a0 [ +0.000004] kthread+0xfb/0x130 [ +0.000004] ? process_one_work+0x350/0x350 [ +0.000003] ? kthread_park+0x90/0x90 [ +0.000005] ret_from_fork+0x1f/0x40 Reported-by: Kenneth Graunke <kenneth@whitecape.org> Fixes: c9ad602feabe ("drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtree") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Kenneth Graunke <kenneth@whitecape.org> Cc: Matthew Auld <matthew.auld@intel.com> Tested-by: Kenneth Graunke <kenneth@whitecape.org> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> Link: https://patchwork.freedesktop.org/patch/msgid/20191205183332.801237-1-chris@chris-wilson.co.uk
2019-12-02drm/i915: Serialise i915_active_wait() with its retirementChris Wilson
As the i915_active.retire() may be running on another CPU as we detect that the i915_active is idle, we may not wait for the retirement itself. Wait for the remote callback by waiting for the retirement worker. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112424 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/20191202140133.2444217-2-chris@chris-wilson.co.uk
2019-12-02drm/i915: Specialise i915_active.work lock classesChris Wilson
Similar to for i915_active.mutex, we require each class of i915_active to have distinct lockdep chains as some, but by no means all, i915_active are used within the shrinker and so have much more severe usage constraints. By using a lockclass local to i915_active_init() all i915_active workers have the same lock class, and we may generate false positives when waiting for the i915_active. If we push the lockclass into the caller, each class of i915_active will have distinct lockdep chains. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191202140133.2444217-1-chris@chris-wilson.co.uk
2019-11-27drm/i915: Serialise i915_active_fence_set() with itselfChris Wilson
The expected downside to commit 58b4c1a07ada ("drm/i915: Reduce nested prepare_remote_context() to a trylock") was that it would need to return -EAGAIN to userspace in order to resolve potential mutex inversion. Such an unsightly round trip is unnecessary if we could atomically insert a barrier into the i915_active_fence, so make it happen. Currently, we use the timeline->mutex (or some other named outer lock) to order insertion into the i915_active_fence (and so individual nodes of i915_active). Inside __i915_active_fence_set, we only need then serialise with the interrupt handler in order to claim the timeline for ourselves. However, if we remove the outer lock, we need to ensure the order is intact between not only multiple threads trying to insert themselves into the timeline, but also with the interrupt handler completing the previous occupant. We use xchg() on insert so that we have an ordered sequence of insertions (and each caller knows the previous fence on which to wait, preserving the chain of all fences in the timeline), but we then have to cmpxchg() in the interrupt handler to avoid overwriting the new occupant. The only nasty side-effect is having to temporarily strip off the RCU-annotations to apply the atomic operations, otherwise the rules are much more conventional! Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112402 Fixes: 58b4c1a07ada ("drm/i915: Reduce nested prepare_remote_context() to a trylock") 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/20191127134527.3438410-1-chris@chris-wilson.co.uk
2019-11-20drm/i915: Mark up the calling context for intel_wakeref_put()Chris Wilson
Previously, we assumed we could use mutex_trylock() within an atomic context, falling back to a worker if contended. However, such trickery is illegal inside interrupt context, and so we need to always use a worker under such circumstances. As we normally are in process context, we can typically use a plain mutex, and only defer to a work when we know we are being called from an interrupt path. Fixes: 51fbd8de87dc ("drm/i915/pmu: Atomically acquire the gt_pm wakeref") References: a0855d24fc22d ("locking/mutex: Complain upon mutex API misuse in IRQ contexts") References: https://bugs.freedesktop.org/show_bug.cgi?id=111626 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/20191120125433.3767149-1-chris@chris-wilson.co.uk
2019-11-14drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtreeChris Wilson
As we want to be able to run inside atomic context for retiring the i915_active, and we are no longer allowed to abuse mutex_trylock, split the tree management portion of i915_active.mutex into an irq-safe spinlock. References: a0855d24fc22d ("locking/mutex: Complain upon mutex API misuse in IRQ contexts") References: https://bugs.freedesktop.org/show_bug.cgi?id=111626 Fixes: 274cbf20fd10 ("drm/i915: Push the i915_active.retire into a worker") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191114172535.1116-1-chris@chris-wilson.co.uk
2019-10-24drm/i915/gt: Split intel_ring_submissionChris Wilson
Split the legacy submission backend from the common CS ring buffer handling. 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/20191024100344.5041-1-chris@chris-wilson.co.uk
2019-10-21drm/i915/gt: Introduce barrier pulses along enginesChris Wilson
To flush idle barriers, and even inflight requests, we want to send a preemptive 'pulse' along an engine. We use a no-op request along the pinned kernel_context at high priority so that it should run or else kick off the stuck requests. We can use this to ensure idle barriers are immediately flushed, as part of a context cancellation mechanism, or as part of a heartbeat mechanism to detect and reset a stuck GPU. 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/20191021174339.5389-1-chris@chris-wilson.co.uk
2019-10-18drm/i915: Make for_each_engine_masked work on intel_gtTvrtko Ursulin
Medium term goal is to eliminate the i915->engine[] array and to get there we have recently introduced equivalent array in intel_gt. Now we need to migrate the code further towards this state. This next step is to eliminate usage of i915->engines[] from the for_each_engine_masked iterator. For this to work we also need to use engine->id as index when populating the gt->engine[] array and adjust the default engine set indexing to use engine->legacy_idx instead of assuming gt->engines[] indexing. v2: * Populate gt->engine[] earlier. * Check that we don't duplicate engine->legacy_idx v3: * Work around the initialization order issue between default_engines() and intel_engines_driver_register() which sets engine->legacy_idx for now. It will be fixed properly later. v4: * Merge with forgotten v2.5. 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> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/20191017161852.8836-1-tvrtko.ursulin@linux.intel.com
2019-10-04drm/i915: Move idle barrier cleanup into engine-pmChris Wilson
Now that we now longer need to guarantee that the active callback is under the struct_mutex, we can lift it out of the i915_gem_park() and into the engine parking itself. 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/20191004134015.13204-7-chris@chris-wilson.co.uk
2019-10-04drm/i915: Coordinate i915_active with its own mutexChris Wilson
Forgo the struct_mutex serialisation for i915_active, and interpose its own mutex handling for active/retire. This is a multi-layered sleight-of-hand. First, we had to ensure that no active/retire callbacks accidentally inverted the mutex ordering rules, nor assumed that they were themselves serialised by struct_mutex. More challenging though, is the rule over updating elements of the active rbtree. Instead of the whole i915_active now being serialised by struct_mutex, allocations/rotations of the tree are serialised by the i915_active.mutex and individual nodes are serialised by the caller using the i915_timeline.mutex (we need to use nested spinlocks to interact with the dma_fence callback lists). The pain point here is that instead of a single mutex around execbuf, we now have to take a mutex for active tracker (one for each vma, context, etc) and a couple of spinlocks for each fence update. The improvement in fine grained locking allowing for multiple concurrent clients (eventually!) should be worth it in typical loads. v2: Add some comments that barely elucidate anything :( 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/20191004134015.13204-6-chris@chris-wilson.co.uk
2019-10-04drm/i915: Push the i915_active.retire into a workerChris Wilson
As we need to use a mutex to serialise i915_active activation (because we want to allow the callback to sleep), we need to push the i915_active.retire into a worker callback in case we get need to retire from an atomic context. 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/20191004134015.13204-5-chris@chris-wilson.co.uk
2019-10-04drm/i915: Pull i915_vma_pin under the vm->mutexChris Wilson
Replace the struct_mutex requirement for pinning the i915_vma with the local vm->mutex instead. Note that the vm->mutex is tainted by the shrinker (we require unbinding from inside fs-reclaim) and so we cannot allocate while holding that mutex. Instead we have to preallocate workers to do allocate and apply the PTE updates after we have we reserved their slot in the drm_mm (using fences to order the PTE writes with the GPU work and with later unbind). In adding the asynchronous vma binding, one subtle requirement is to avoid coupling the binding fence into the backing object->resv. That is the asynchronous binding only applies to the vma timeline itself and not to the pages as that is a more global timeline (the binding of one vma does not need to be ordered with another vma, nor does the implicit GEM fencing depend on a vma, only on writes to the backing store). Keeping the vma binding distinct from the backing store timelines is verified by a number of async gem_exec_fence and gem_exec_schedule tests. The way we do this is quite simple, we keep the fence for the vma binding separate and only wait on it as required, and never add it to the obj->resv itself. Another consequence in reducing the locking around the vma is the destruction of the vma is no longer globally serialised by struct_mutex. A natural solution would be to add a kref to i915_vma, but that requires decoupling the reference cycles, possibly by introducing a new i915_mm_pages object that is own by both obj->mm and vma->pages. However, we have not taken that route due to the overshadowing lmem/ttm discussions, and instead play a series of complicated games with trylocks to (hopefully) ensure that only one destruction path is called! v2: Add some commentary, and some helpers to reduce patch churn. 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/20191004134015.13204-4-chris@chris-wilson.co.uk
2019-09-20drm/i915: Mark i915_request.timeline as a volatile, rcu pointerChris Wilson
The request->timeline is only valid until the request is retired (i.e. before it is completed). Upon retiring the request, the context may be unpinned and freed, and along with it the timeline may be freed. We therefore need to be very careful when chasing rq->timeline that the pointer does not disappear beneath us. The vast majority of users are in a protected context, either during request construction or retirement, where the timeline->mutex is held and the timeline cannot disappear. It is those few off the beaten path (where we access a second timeline) that need extra scrutiny -- to be added in the next patch after first adding the warnings about dangerous access. One complication, where we cannot use the timeline->mutex itself, is during request submission onto hardware (under spinlocks). Here, we want to check on the timeline to finalize the breadcrumb, and so we need to impose a second rule to ensure that the request->timeline is indeed valid. As we are submitting the request, it's context and timeline must be pinned, as it will be used by the hardware. Since it is pinned, we know the request->timeline must still be valid, and we cannot submit the idle barrier until after we release the engine->active.lock, ergo while submitting and holding that spinlock, a second thread cannot release the timeline. v2: Don't be lazy inside selftests; hold the timeline->mutex for as long as we need it, and tidy up acquiring the timeline with a bit of refactoring (i915_active_add_request) 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/20190919111912.21631-1-chris@chris-wilson.co.uk
2019-08-27drm/i915: Only activate i915_active debugobject onceChris Wilson
The point of debug_object_activate is to mark the first, and only the first, acquisition. The object then remains active until the last release. However, we marked up all successful first acquires even though we allowed concurrent parties to try and acquire the i915_active simultaneously (serialised by the i915_active.mutex). Testcase: igt/gem_mmap_gtt/fault-concurrent 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/20190827132631.18627-1-chris@chris-wilson.co.uk
2019-08-19drm/i915: i915_active.retire() is optionalChris Wilson
Check that i915_active.retire() exists before calling. 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/20190819075835.20065-6-chris@chris-wilson.co.uk
2019-08-16drm/i915: Markup expected timeline locks for i915_activeChris Wilson
As every i915_active_request should be serialised by a dedicated lock, i915_active consists of a tree of locks; one for each node. Markup up the i915_active_request with what lock is supposed to be guarding it so that we can verify that the serialised updated are indeed serialised. 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/20190816121000.8507-2-chris@chris-wilson.co.uk
2019-08-14drm/i915: Serialise read/write of the barrier's engineChris Wilson
We use the request pointer inside the i915_active_node as the indicator of the barrier's status; we mark it as used during i915_request_add_active_barriers(), and search for an available barrier in reuse_idle_barrier(). That check must be carefully serialised to ensure we do use an engine for the barrier and not just a random pointer. (Along the other reuse path, we are fully serialised by the timeline->mutex.) The acquisition of the barrier itself is ordered through the strong memory barrier in llist_del_all(). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111397 Fixes: d8af05ff38ae ("drm/i915: Allow sharing the idle-barrier from other kernel requests") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190813200905.11369-1-chris@chris-wilson.co.uk
2019-08-09drm/i915: Lift timeline into intel_contextChris Wilson
Move the timeline from being inside the intel_ring to intel_context itself. This saves much pointer dancing and makes the relations of the context to its timeline much clearer. 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/20190809182518.20486-4-chris@chris-wilson.co.uk
2019-08-02drm/i915: Allow sharing the idle-barrier from other kernel requestsChris Wilson
By placing our idle-barriers in the i915_active fence tree, we expose those for reuse by other components that are issuing requests along the kernel_context. Reusing the proto-barrier active_node is perfectly fine as the new request implies a context-switch, and so an opportune point to run the idle-barrier. However, the proto-barrier is not equivalent to a normal active_node and care must be taken to avoid dereferencing the ERR_PTR used as its request marker. v2: Comment the more egregious cheek v3: A glossary! Reported-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Fixes: ce476c80b8bf ("drm/i915: Keep contexts pinned until after the next kernel context switch") Fixes: a9877da2d629 ("drm/i915/oa: Reconfigure contexts on the fly") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190802100015.1281-1-chris@chris-wilson.co.uk
2019-07-26drm/i915: Do not rely on for loop caching the maskTvrtko Ursulin
for_each_engine_masked caches the engine mask but what does the caller know. Cache it explicitly for clarity and while at it correct the type to match. 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/20190725125056.11942-1-tvrtko.ursulin@linux.intel.com
2019-07-26drm/i915: Capture vma contents outside of spinlockChris Wilson
Currently we use the engine->active.lock to ensure that the request is not retired as we capture the data. However, we only need to ensure that the vma are not removed prior to use acquiring their contents, and since we have already relinquished our stop-machine protection, we assume that the user will not be overwriting the contents before we are able to record them. In order to capture the vma outside of the spinlock, we acquire a reference and mark the vma as active to prevent it from being unbound. However, since it is tricky allocate an entry in the fence tree (doing so would require taking a mutex) while inside the engine spinlock, we use an atomic bit and special case the handling for i915_active_wait. The core benefit is that we can use some non-atomic methods for mapping the device pages, we can remove the slow compression phase out of atomic context (i.e. stop antagonising the nmi-watchdog), and no we longer need large reserves of atomic pages. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111215 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190725223843.8971-1-chris@chris-wilson.co.uk
2019-07-03drm/i915: Markup potential lock for i915_activeChris Wilson
Make the lockchains more deterministic via i915_active by flagging the potential lock. 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/20190703091726.11690-7-chris@chris-wilson.co.uk
2019-07-02drm/i915: Report if i915_active is still busy upon waitingChris Wilson
If we try to wait on an i915_active from within a critical section, it will remain busy (such as if we are shrinking from within i915_active_ref). Report the failure so that we do not proceed thinking it is idle. Extracted from a future patch "drm/i915: Coordinate i915_active with its own mutex". Fixes: 12c255b5dad1 ("drm/i915: Provide an i915_active.acquire callback") 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/20190702092117.1707-1-chris@chris-wilson.co.uk
2019-06-21drm/i915: Provide an i915_active.acquire callbackChris Wilson
If we introduce a callback for i915_active that is only called the first time we use the i915_active and is symmetrically paired with the i915_active.retire callback, we can replace the open-coded and non-atomic implementations -- which will be very fragile (i.e. broken) upon removing the struct_mutex serialisation. 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/20190621183801.23252-4-chris@chris-wilson.co.uk
2019-06-21drm/i915: Track i915_active using debugobjectsChris Wilson
Provide runtime asserts and tracking of i915_active via debugobjects. For example, this should allow us to check that the i915_active is only active when we expect it to be and is never freed too early. One consequence is that, for simplicity, we no longer allow i915_active to be on-stack which only affected the selftests. 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/20190621183801.23252-2-chris@chris-wilson.co.uk