Commit Graph

810819 Commits

Author SHA1 Message Date
Chris Wilson 5f5c139d69 drm/i915: Allocate active tracking nodes from a slabcache
Wrap the active tracking for a GPU references in a slabcache for faster
allocations, and hopefully better fragmentation reduction.

v3: Nothing device specific left, it's just a slabcache that we can
make global.
v4: Include i915_active.h and don't put the initfunc under DEBUG_GEM

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/20190205130005.2807-4-chris@chris-wilson.co.uk
2019-02-05 17:17:34 +00:00
Chris Wilson a42375af0a drm/i915: Release the active tracker tree upon idling
As soon as we detect that the active tracker is idle and we prepare to
call the retire callback, release the storage for our tree of
per-timeline nodes. We expect these to be infrequently used and quick
to allocate, so there is little benefit in keeping the tree cached and
we would prefer to return the pages back to the system in a timely
fashion.

This also means that when we finalize the struct as a whole, we know as
the activity tracker must be idle, the tree has already been released.
Indeed we can reduce i915_active_fini() just to the assertions that there
is nothing to do.

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/20190205130005.2807-3-chris@chris-wilson.co.uk
2019-02-05 17:14:33 +00:00
Chris Wilson 64d6c500a3 drm/i915: Generalise GPU activity tracking
We currently track GPU memory usage inside VMA, such that we never
release memory used by the GPU until after it has finished accessing it.
However, we may want to track other resources aside from VMA, or we may
want to split a VMA into multiple independent regions and track each
separately. For this purpose, generalise our request tracking (akin to
struct reservation_object) so that we can embed it into other objects.

v2: Tweak error handling during selftest setup.

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/20190205130005.2807-2-chris@chris-wilson.co.uk
2019-02-05 17:12:00 +00:00
Chris Wilson a21f453c73 drm/i915/selftests: Exercise some AB...BA preemption chains
Build a chain using 2 contexts (A, B) then request a preemption such
that a later A request runs before the spinner in B.

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/20190205123835.25331-1-chris@chris-wilson.co.uk
2019-02-05 16:16:02 +00:00
Tvrtko Ursulin c06ee6ff2c drm/i915/selftests: Context SSEU reconfiguration tests
Exercise the context image reconfiguration logic for idle and busy
contexts, with the resets thrown into the mix as well.

Free from the uAPI restrictions this test runs on all Gen9+ platforms
with slice power gating.

v2:
 * Rename some helpers for clarity.
 * Include subtest names in error logs.
 * Remove unnecessary function export.

v3:
 * Rebase for RUNTIME_INFO.

v4:
 * Fix incomplete unexport from v2. (Chris Wilson)

v5:
 * Rebased for runtime pm api changes.

v6:
 * Rebased for i915_reset.c.

v7:
 * Tidy checkpatch warnings.
 * Consolidate error checking and logging a bit.
 * Skip idle test phase if something failed before it.

v8:
 (Chris Wilson)
 * Fix i915_request_wait error handling.
 * No need to PIN_HIGH the VMA.
 * Remove pointless GEM_BUG_ON before pointer dereference.

v9:
 * Avoid rq leak if rpcs query fails. (Chris)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> # v6
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-5-tvrtko.ursulin@linux.intel.com
2019-02-05 11:32:03 +00:00
Tvrtko Ursulin e46c2e99f6 drm/i915: Expose RPCS (SSEU) configuration to userspace (Gen11 only)
We want to allow userspace to reconfigure the subslice configuration on a
per context basis.

This is required for the functional requirement of shutting down non-VME
enabled sub-slices on Gen11 parts.

To do so, we expose a context parameter to allow adjustment of the RPCS
register stored within the context image (and currently not accessible via
LRI).

If the context is adjusted before first use or whilst idle, the adjustment
is for "free"; otherwise if the context is active we queue a request to do
so (using the kernel context), following all other activity by that
context, which is also marked as barrier for all following submission
against the same context.

Since the overhead of device re-configuration during context switching can
be significant, especially in multi-context workloads, we limit this new
uAPI to only support the Gen11 VME use case. In this use case either the
device is fully enabled, and exactly one slice and half of the subslices
are enabled.

Example usage:

	struct drm_i915_gem_context_param_sseu sseu = { };
	struct drm_i915_gem_context_param arg = {
		.param = I915_CONTEXT_PARAM_SSEU,
		.ctx_id = gem_context_create(fd),
		.size = sizeof(sseu),
		.value = to_user_pointer(&sseu)
	};

	/* Query device defaults. */
	gem_context_get_param(fd, &arg);

	/* Set VME configuration on a 1x6x8 part. */
	sseu.slice_mask = 0x1;
	sseu.subslice_mask = 0xe0;
	gem_context_set_param(fd, &arg);

v2: Fix offset of CTX_R_PWR_CLK_STATE in intel_lr_context_set_sseu()
    (Lionel)

v3: Add ability to program this per engine (Chris)

v4: Move most get_sseu() into i915_gem_context.c (Lionel)

v5: Validate sseu configuration against the device's capabilities (Lionel)

v6: Change context powergating settings through MI_SDM on kernel context
    (Chris)

v7: Synchronize the requests following a powergating setting change using
    a global dependency (Chris)
    Iterate timelines through dev_priv.gt.active_rings (Tvrtko)
    Disable RPCS configuration setting for non capable users
    (Lionel/Tvrtko)

v8: s/union intel_sseu/struct intel_sseu/ (Lionel)
    s/dev_priv/i915/ (Tvrtko)
    Change uapi class/instance fields to u16 (Tvrtko)
    Bump mask fields to 64bits (Lionel)
    Don't return EPERM when dynamic sseu is disabled (Tvrtko)

v9: Import context image into kernel context's ppgtt only when
    reconfiguring powergated slice/subslices (Chris)
    Use aliasing ppgtt when needed (Michel)

Tvrtko Ursulin:

v10:
 * Update for upstream changes.
 * Request submit needs a RPM reference.
 * Reject on !FULL_PPGTT for simplicity.
 * Pull out get/set param to helpers for readability and less indent.
 * Use i915_request_await_dma_fence in add_global_barrier to skip waits
   on the same timeline and avoid GEM_BUG_ON.
 * No need to explicitly assign a NULL pointer to engine in legacy mode.
 * No need to move gen8_make_rpcs up.
 * Factored out global barrier as prep patch.
 * Allow to only CAP_SYS_ADMIN if !Gen11.

v11:
 * Remove engine vfunc in favour of local helper. (Chris Wilson)
 * Stop retiring requests before updates since it is not needed
   (Chris Wilson)
 * Implement direct CPU update path for idle contexts. (Chris Wilson)
 * Left side dependency needs only be on the same context timeline.
   (Chris Wilson)
 * It is sufficient to order the timeline. (Chris Wilson)
 * Reject !RCS configuration attempts with -ENODEV for now.

v12:
 * Rebase for make_rpcs.

v13:
 * Centralize SSEU normalization to make_rpcs.
 * Type width checking (uAPI <-> implementation).
 * Gen11 restrictions uAPI checks.
 * Gen11 subslice count differences handling.
 Chris Wilson:
 * args->size handling fixes.
 * Update context image from GGTT.
 * Postpone context image update to pinning.
 * Use i915_gem_active_raw instead of last_request_on_engine.

v14:
 * Add activity tracker on intel_context to fix the lifetime issues
   and simplify the code. (Chris Wilson)

v15:
 * Fix context pin leak if no space in ring by simplifying the
   context pinning sequence.

v16:
 * Rebase for context get/set param locking changes.
 * Just -ENODEV on !Gen11. (Joonas)

v17:
 * Fix one Gen11 subslice enablement rule.
 * Handle error from i915_sw_fence_await_sw_fence_gfp. (Chris Wilson)

v18:
 * Update commit message. (Joonas)
 * Restrict uAPI to VME use case. (Joonas)

v19:
 * Rebase.

v20:
 * Rebase for ce->active_tracker.

v21:
 * Rebase for IS_GEN changes.

v22:
 * Reserve uAPI for flags straight away. (Chris Wilson)

v23:
 * Rebase for RUNTIME_INFO.

v24:
 * Added some headline docs for the uapi usage. (Joonas/Chris)

v25:
 * Renamed class/instance to engine_class/engine_instance to avoid clash
   with C++ keyword. (Tony Ye)

v26:
 * Rebased for runtime pm api changes.

v27:
 * Rebased for intel_context_init.
 * Wrap commit msg to 75.

v28:
 (Chris Wilson)
 * Use i915_gem_ggtt.
 * Use i915_request_await_dma_fence to show a better example.

v29:
 * i915_timeline_set_barrier can now fail. (Chris Wilson)

v30:
 * Capture some acks.

v31:
 * Drop the WARN_ON from use controllable paths. (Chris Wilson)
 * Use overflows_type for all checks.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100899
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107634
Issue: https://github.com/intel/media-driver/issues/267
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Zhipeng Gong <zhipeng.gong@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tony Ye <tony.ye@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Timo Aaltonen <timo.aaltonen@canonical.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Stéphane Marchesin <marcheu@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-4-tvrtko.ursulin@linux.intel.com
2019-02-05 11:32:03 +00:00
Tvrtko Ursulin 7810858412 drm/i915: Add timeline barrier support
Timeline barrier allows serialization between different timelines.

After calling i915_timeline_set_barrier with a request, all following
submissions on this timeline will be set up as depending on this request,
or barrier. Once the barrier has been completed it automatically gets
cleared and things continue as normal.

This facility will be used by the upcoming context SSEU code.

v2:
 * Assert barrier has been retired on timeline_fini. (Chris Wilson)
 * Fix mock_timeline.

v3:
 * Improved comment language. (Chris Wilson)

v4:
 * Maintain ordering with previous barriers set on the timeline.

v5:
 * Rebase.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-3-tvrtko.ursulin@linux.intel.com
2019-02-05 11:32:03 +00:00
Lionel Landwerlin ec431eae8f drm/i915/perf: lock powergating configuration to default when active
If some of the contexts submitting workloads to the GPU have been
configured to shutdown slices/subslices, we might loose the NOA
configurations written in the NOA muxes.

One possible solution to this problem is to reprogram the NOA muxes
when we switch to a new context. We initially tried this in the
workaround batchbuffer but some concerns where raised about the cost
of reprogramming at every context switch. This solution is also not
without consequences from the userspace point of view. Reprogramming
of the muxes can only happen once the powergating configuration has
changed (which happens after context switch). This means for a window
of time during the recording, counters recorded by the OA unit might
be invalid. This requires userspace dealing with OA reports to discard
the invalid values.

Minimizing the reprogramming could be implemented by tracking of the
last programmed configuration somewhere in GGTT and use MI_PREDICATE
to discard some of the programming commands, but the command streamer
would still have to parse all the MI_LRI instructions in the
workaround batchbuffer.

Another solution, which this change implements, is to simply disregard
the user requested configuration for the period of time when i915/perf
is active.

On most platforms there are no issues with this apart from a performance
penality for some media workloads that benefit from running on a partially
powergated GPU. We already prevent RC6 from affecting the programming so
it doesn't sound completely unreasonable to hold on powergating for the
same reason.

On Icelake however there would a functional problem if the slices not-
containing the VME block were left enabled with a running media workload
which explicitly disabled them. To avoid a GPU hang in this case, on
Icelake we lock the enablement to only slices which contain VME blocks.
Downside is that it means degraded GPU performance when OA is active but
there is no known alternative solution for this.

v2: Leave RPCS programming in intel_lrc.c (Lionel)

v3: Update for s/union intel_sseu/struct intel_sseu/ (Lionel)
    More to_intel_context() (Tvrtko)
    s/dev_priv/i915/ (Tvrtko)

Tvrtko Ursulin:

v4:
 * Rebase for make_rpcs changes.

v5:
 * Apply OA restriction from make_rpcs directly.

v6:
 * Rebase for context image setup changes.

v7:
 * Move stream assignment before metric enable.

v8-9:
 * Rebase.

v10:
 * Squashed with ICL support patch.

Bspec: 21140
Co-developed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> # v9
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-2-tvrtko.ursulin@linux.intel.com
2019-02-05 11:31:52 +00:00
Lionel Landwerlin 87f1ef2252 drm/i915: Record the sseu configuration per-context & engine
We want to expose the ability to reconfigure the slices, subslice and
eu per context and per engine. To facilitate that, store the current
configuration on the context for each engine, which is initially set
to the device default upon creation.

v2: record sseu configuration per context & engine (Chris)

v3: introduce the i915_gem_context_sseu to store powergating
    programming, sseu_dev_info has grown quite a bit (Lionel)

v4: rename i915_gem_sseu into intel_sseu (Chris)
    use to_intel_context() (Chris)

v5: More to_intel_context() (Tvrtko)
    Switch intel_sseu from union to struct (Tvrtko)
    Move context default sseu in existing loop (Chris)

v6: s/intel_sseu_from_device_sseu/intel_device_default_sseu/ (Tvrtko)

Tvrtko Ursulin:

v7:
 * Pass intel_sseu by pointer instead of value to make_rpcs.
 * Rebase for make_rpcs changes.

v8:
 * Rebase for RPCS edit on pin.

v9:
 * Rebase for context image setup changes.

v10:
 * Rename dev_priv to i915. (Chris Wilson)

v11:
 * Rebase.

v12:
 * Rebase for IS_GEN changes.

v13:
 * Rebase for RUNTIME_INFO.

v14:
 * Rebase for intel_context_init.

v15:
 * Rebase for drm-tip changes.

v16:
 * Moved struct intel_sseu definition to i915_gem_context.h.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-1-tvrtko.ursulin@linux.intel.com
2019-02-05 11:31:27 +00:00
Chris Wilson 1413b2bc07 drm/i915: Trim NEWCLIENT boosting
Limit the NEWCLIENT boost to only give its small priority boost to fresh
clients only that have no dependencies.

The idea for using NEWCLIENT boosting, commit b16c765122 ("drm/i915:
Priority boost for new clients"), is that short-lived streams are often
interactive and require lower latency -- and that by executing those
ahead of the long running hogs, the short-lived clients do little to
interfere with the system throughput by virtue of their short-lived
nature. However, we were only considering the client's own timeline for
determining whether or not it was a fresh stream. This allowed for
compositors to wake up before their vblank and bump all of its client
streams. However, in testing with media-bench this results in chaining
all cooperating contexts together preventing us from being able to
reorder contexts to reduce bubbles (pipeline stalls), overall increasing
latency, and reducing system throughput. The exact opposite of our
intent. The compromise of applying the NEWCLIENT boost to strictly fresh
clients (that do not wait upon anything else) should maintain the
"real-time response under load" characteristics of FQ_CODEL, without
locking together the long chains of dependencies across the system.

References: b16c765122 ("drm/i915: Priority boost for new clients")
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/20190204150101.30759-1-chris@chris-wilson.co.uk
2019-02-04 21:54:38 +00:00
Chris Wilson 3d7a64b992 drm/i915: Allow normal clients to always preempt idle priority clients
When first enabling preemption, we hesitated from making it a free-for-all
where every higher priority client would force a preempt-to-idle cycle
and take over from all lower priority clients. We hesitated because we
were uncertain just how well preemption would work in practice, whether
the preemption latency itself would detract from the latency gains for
higher priority tasks and whether it would work at all. Since
introducing preemption, we have been enabling it for more common tasks,
even giving normal clients a small preemptive boost when they first
start (to aide fairness and improve interactivity). Now lets take one
step further and give permission for all normal (priority:0) clients to
preempt any idle (priority:<0) task so that users running long compute
jobs do not overly impact other jobs (i.e. their desktop) and the system
remains responsive under such idle loads.

References: f6322eddaf ("drm/i915/preemption: Allow preemption between submission ports")
References: b16c765122 ("drm/i915: Priority boost for new clients")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: "Bloomfield, Jon" <jon.bloomfield@intel.com>
Cc: "Stead, Alan" <alan.stead@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/20190204084116.3013-1-chris@chris-wilson.co.uk
2019-02-04 09:47:28 +00:00
Rodrigo Vivi 46c0cd8c56 drm/i915: Update DRIVER_DATE to 20190202
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2019-02-02 00:14:28 -08:00
Rodrigo Vivi 5e0f5a58b1 drm/i915/cfl: Adding another PCI Device ID.
While cross checking PCI IDs from Intel Media SDK
and kernel Dmitry noticed this gap. So we checked the
spec and this new ID had been recently added.

v2: Adding new H_GT1 entry to i915_pci.c (Jose)

Reported-by: Dmitry Rogozhkin<dmitry.v.rogozhkin@intel.com>
Cc: Dmitry Rogozhkin<dmitry.v.rogozhkin@intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190201235049.27206-1-rodrigo.vivi@intel.com
2019-01-31 08:53:59 -08:00
Rodrigo Vivi 1b4fd5d38c Merge tag 'gvt-next-2019-02-01' of https://github.com/intel/gvt-linux into drm-intel-next-queued
gvt-next-2019-02-01

- new VFIO EDID region support (Henry)

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
From: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190201061523.GE5588@zhen-hp.sh.intel.com
2019-02-01 09:03:24 -08:00
Hans de Goede 7360c9f6b8 drm/i915: Enable fastboot by default on VLV and CHV
We really want to have fastboot enabled by default to avoid an ugly
modeset during boot.

Currently we are enabling fastboot by default on gen9+ (Skylake and newer).
The intention is to enable it on older generations after it has seen more
testing on gen9+.

VLV and CHV devices are still being sold in stores today, as such it is
desirable to also enable fastboot by default on these now.

I've extensively tested fastboot=1 support on over 50 different
Bay- and Cherry-Trail devices. Testing DSI and eDP panels as well as
HDMI output (and even DP over Type-C on one device).

All 50 devices work fine with fastboot=1. On 2 devices their DSI panel
turns black as soon as the i915 driver loads when fastboot=0, so having
fastboot enabled is required for these 2 to work properly (for lack of
a better fix).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129142237.8684-1-hdegoede@redhat.com
2019-02-01 10:15:06 +01:00
Talha Nassar 0b904c890a drm/i915/icl: restore WaEnableFloatBlendOptimization
Enables blend optimization for floating point RTs

This restores the workaround that was reverted in c358514ba8
("Revert "drm/i915/icl: WaEnableFloatBlendOptimization"").

The revert was due to the register write seemingly not sticking,
but the HW team has confirmed that this is because the
register is WO and that the workaround is indeed required.

Here the wa is added with a mask of 0 since the register is WO.

References: https://hsdes.intel.com/resource/1408134172
References: https://bugs.freedesktop.org/show_bug.cgi?id=107338
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>

Signed-off-by: Talha Nassar <talha.nassar@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/1548983324-15344-4-git-send-email-talha.nassar@intel.com
2019-02-01 08:39:53 +00:00
Tvrtko Ursulin ae598b0d6b drm/i915: Save some lines of source code in workarounds
No functional or code size change - just notice we can compact the source
by re-using a single helper for adding workarounds.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@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/1548983324-15344-3-git-send-email-talha.nassar@intel.com
2019-02-01 08:39:52 +00:00
Tvrtko Ursulin 69b768f2bc drm/i915: Move workaround infrastructure code up
Top comment in intel_workarounds.c says common code should come first so
lets respect that. Also, by moving the common code together opportunities
to reduce duplication will become more obvious.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@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/1548983324-15344-2-git-send-email-talha.nassar@intel.com
2019-02-01 08:39:51 +00:00
Imre Deak 2b34e56236 drm/i915/icl: Work around broken VBTs for port F detection
VBT may include incorrect information about the presence of port F. Work
around this on SKUs where we know the port is not present.

v2:
- Fix IS_ICL_WITH_PORT_F, so it's useable from any context.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108915
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181220155211.31456-1-imre.deak@intel.com
2019-01-31 16:31:22 +02:00
Imre Deak 828ccb31cf drm/i915/icl: Add TypeC ports only if VBT is present
We can't safely probe Type C ports, whether they are a legacy or a
USB/Thunderbolt DP Alternate Type C port. This would require performing
the TypeC connect sequence - as described by the specification - but
that may have unwanted side-effects. These side-effects include at least
- without completeness - timeouts during AUX power well enabling and
subsequent PLL enabling errors.

To safely identify these ports we really need VBT, which has the proper
flag for this (ddi_vbt_port_info::supports_typec_usb, supports_tbt).
Based on the above disable Type C ports if we can't load VBT for some
reason.

v2:
- Notice that we disable TypeC ports completely and simplify accordingly
  (Jose).
- Add code comment explaining why we disabled the ports. (Jani)

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128114242.28666-1-imre.deak@intel.com
2019-01-31 16:28:33 +02:00
Ville Syrjälä 8aae2b1cdf drm/i915: Pick the first unused PLL once again
commit 5b0bd14dcc ("drm/i915/icl: keep track of unused pll while
looping") inadvertently (I presume) changed the code to pick the
last unused dpll rather than the first unused one like we did before.

While there should most likely be no harm in changing the order
let's change back just to avoid a change in the behaviour. At
least it might reduce the confusion when staring at logs (took
me a while to figure out why DPLL1 being picked over DPLL0
when the latter was most definitely available).

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190130181359.20693-1-ville.syrjala@linux.intel.com
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
2019-01-31 09:46:02 +02:00
Ville Syrjälä ad3e7b824c drm/i915: Don't use the second dbuf slice on icl
The code managing the dbuf slices is borked and needs some
real work to fix. In the meantime let's just stop using the
second slice.

v2: Drop the change to intel_enabled_dbuf_slices_num() (Mahesh)

Cc: Mahesh Kumar <mahesh1.sh.kumar@gmail.com>
Reviewed-by: Imre Deak <imre.deak@intel.com> #v1
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190130155110.12918-1-ville.syrjala@linux.intel.com
Reviewed-by: Mahesh Kumar <mahesh1.sh.kumar@gmail.com>
2019-01-31 09:00:08 +02:00
Hang Yuan 39c68e87bc drm/i915/gvt: add VFIO EDID region
Implement VFIO EDID region for vgpu. Support EDID blob update and notify
guest on link state change via hotplug event.

v3: move struct edid_region to kvmgt.c <zhenyu>
v2: add EDID sanity check and size update <zhenyu>

Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2019-01-31 11:41:25 +08:00
Hang Yuan 1ca20f33df drm/i915/gvt: add hotplug emulation
Add function to emulate hotplug interrupt for SKL/KBL platforms

Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2019-01-31 11:26:55 +08:00
Hang Yuan 4922078961 drm/i915/gvt: add functions to get default resolution
These functions will get default resolution according to vgpu type.

Signed-off-by: Hang Yuan <hang.yuan@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
2019-01-31 11:26:48 +08:00
Matt Roper e4c0d5314d drm/i915: Apply LUT validation checks to platforms more accurately (v3)
Use of the new DRM_COLOR_LUT_NON_DECREASING test was a bit over-zealous;
it doesn't actually need to be applied to the degamma on "bdw-style"
platforms.  Likewise, we overlooked the fact that CHV should have that
test applied to the gamma LUT as well as the degamma LUT.

Rather than adding more complicated platform checking to
intel_color_check(), let's just store the appropriate set of LUT
validation flags for each platform in the intel_device_info structure.

v2:
 - Shuffle around LUT size tests so that the hardware-specific tests
   won't be applied to legacy gamma tables.  (Ville)
 - Add a debug message so that it will be easier to understand why an
   atomic transaction involving incorrectly-sized LUT's got rejected
   by the driver.

v3:
 - Switch size_t's to int's.  (Ville)

Fixes: 85e2d61e49 ("drm/i915: Validate userspace-provided color management LUT's (v4)")
References: https://lists.freedesktop.org/archives/intel-gfx/2019-January/187634.html
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190130181022.4291-1-matthew.d.roper@intel.com
2019-01-30 17:09:45 -08:00
Matt Roper c0550305fc drm/i915: Force background color to black for gen9+ (v2)
We don't yet allow userspace to control the CRTC background color, but
we should manually program the color to black to ensure the BIOS didn't
leave us with some other color.  We should also set the pipe gamma and
pipe CSC bits so that the background color goes through the same color
management transformations that a plane with black pixels would.

v2: Rename register to SKL_BOTTOM_COLOR to more closely follow
    bspec naming.  (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190130185122.10322-2-matthew.d.roper@intel.com
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
2019-01-30 16:25:15 -08:00
Rodrigo Vivi d54e5f76d8 drm/i915: Update DRIVER_DATE to 20190129
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2019-01-29 17:39:13 -08:00
Ville Syrjälä 717671c610 drm/i915: Use IS_GEN9_LP() for the linetime w/a check
IS_GLK||IS_BXT == IS_GEN9_LP

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-10-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:15:20 +02:00
Ville Syrjälä ff58c11cdb drm/i915: Drop the pointless linetime==0 check
0*whatever==0 so this check is pointless. Remove it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-9-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:14:40 +02:00
Ville Syrjälä ff61a97499 drm/i915: Drop the definite article in front of SAGV
The spec doesn't use a definite article in front of SAGV. The
rules regarding articles and initialisms are super fuzzy, but
at least to my ears it sounds much more natural to not have
the article. Perhaps because I tend to pronounce it as
"sag-vee" instead of spelling out the letters one at a time.
Actually I might still prefer to leave out the article if I
did spell them out.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-8-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2019-01-30 16:14:19 +02:00
Ville Syrjälä 60e983ff18 drm/i915: Pass dev_priv to skl_needs_memory_bw_wa()
skl_needs_memory_bw_wa() doesn't look at the passed in state at all.
Possibly it should, but for now let's make life simpler by just
passing in dev_priv.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-7-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:13:12 +02:00
Ville Syrjälä 961d95e09c drm/i915: Account for minimum ddb allocation restrictions
On icl+ bspec tells us to calculate a separate minimum ddb
allocation from the blocks watermark. Both have to be checked
against the actual ddb allocation, but since we do things the
other way around we'll just calculat the minimum acceptable
ddb allocation by taking the maximum of the two values.

We'll also replace the memcmp() with a full trawl over the
the watermarks so that it'll ignore the min_ddb_alloc
because we can't directly read that out from the hw. I suppose
we could reconstruct it from the other values, but I was
too lazy to do that now.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-6-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:13:08 +02:00
Ville Syrjälä b19c9bcaa2 drm/i915: Fix > vs >= mismatch in watermark/ddb calculations
Bspec says we have to reject the watermark if it's >= the ddb
allocation. Fix the code to reject the == case as it should.
For transition watermarks we can just use >=, for the rest
we'll do +1 when calculating the minimum ddb allocation size.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-5-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:10:47 +02:00
Ville Syrjälä 17b16054b1 drm/i915: Fix bits vs. bytes mixup in dbuf block size computation
The spec used to say "8bpp" which someone took to mean 8 bytes per
pixel when in fact it was supposed to be 8 bits per pixel. The
spec has been updated to make it more clear now. Fix the code
to match.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-4-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:03:01 +02:00
Ville Syrjälä 692927f4e9 drm/i915: Reinstate an early latency==0 check for skl+
I thought we could remove all the early latency==0 checks
and rely on skl_wm_method{1,2}() checking for it. But
skl_compute_plane_wm() applies a bunch of workarounds to bump
up the latency before calling those guys so clearly it won't
end up doing the right thing. Also not sure if the calculations
based on the method1/2 results are safe agaisnt overflows so
it might not work all that well in any case. Let's put the
early check back.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-3-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 16:00:44 +02:00
Ville Syrjälä b52c273be6 drm/i915: Don't ignore level 0 lines watermark for glk+
On glk+ the level 0 lines watermark actually matters. Do not ignore it.
And while at it let's change things so that we always program a
consistnet 0 to the register when the lines watermarks is ignored
by the hardware.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181221171436.8218-2-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
2019-01-30 15:59:43 +02:00
Lucas De Marchi 5b0bd14dcc drm/i915/icl: keep track of unused pll while looping
Instead of looping again on the range of plls, just keep track of one
unused one and use it later.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125222444.19926-5-lucas.demarchi@intel.com
2019-01-29 14:35:07 -08:00
Lucas De Marchi 20fd2ab7be drm/i915/icl: remove dpll from clk_sel
We should not pass DPLL_ID_ICL_DPLL0 or DPLL_ID_ICL_DPLL1 to this
function because the path is only taken for non-combophy ports. Let the
warning trigger if improper value is given.

While at it, rename the function to match the register name we are
trying to program.

v2: fix typo in comment

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125222444.19926-4-lucas.demarchi@intel.com
2019-01-29 14:35:06 -08:00
Lucas De Marchi 7a61a6dec3 drm/i915: always return something on DDI clock selection
Even if we don't have the correct clock and get a warning, we should not
skip the return.

v2: improve commit message (from Joonas)

Fixes: 1fa11ee2d9 ("drm/i915/icl: start adding the TBT pll")
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125222444.19926-3-lucas.demarchi@intel.com
2019-01-29 14:35:04 -08:00
Lucas De Marchi 584fca111d drm/i915/icl: use tc_port in MG_PLL macros
Fix the TODO leftover in the code by changing the argument in MG_PLL
macros. The MG_PLL ids used to access the register values can be
converted from tc_port rather than port.

All these registers can use the TC port to calculate the right offsets
because they are only available for TC ports. The range (PORT_C onwards)
may not be stable and change from platform to platform. So by using the
TC id directly we avoid having to check for the platform in the "leaf
functions" and thus passing dev_priv around.

The helper functions were also renamed to use "tc" as prefix to make
them more generic.

v2: Improve commit message and fix checkpatch warning (from Paulo)

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125222444.19926-2-lucas.demarchi@intel.com
2019-01-29 14:35:02 -08:00
Chris Wilson 789659f430 drm/i915: Drop fake breadcrumb irq
Missed breadcrumb detection is defunct due to the tight coupling with
dma_fence signaling and the myriad ways we may signal fences from
everywhere but from an interrupt, i.e. we frequently signal a fence
before we even see its interrupt. This means that even if we miss an
interrupt for a fence, it still is signaled before our breadcrumb
hangcheck fires, so simplify the breadcrumb hangchecking by moving it
into the GPU hangcheck and forgo fake interrupts.

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/20190129205230.19056-3-chris@chris-wilson.co.uk
2019-01-29 21:45:30 +00:00
Chris Wilson 52c0fdb25c drm/i915: Replace global breadcrumbs with per-context interrupt tracking
A few years ago, see commit 688e6c7258 ("drm/i915: Slaughter the
thundering i915_wait_request herd"), the issue of handling multiple
clients waiting in parallel was brought to our attention. The
requirement was that every client should be woken immediately upon its
request being signaled, without incurring any cpu overhead.

To handle certain fragility of our hw meant that we could not do a
simple check inside the irq handler (some generations required almost
unbounded delays before we could be sure of seqno coherency) and so
request completion checking required delegation.

Before commit 688e6c7258, the solution was simple. Every client
waiting on a request would be woken on every interrupt and each would do
a heavyweight check to see if their request was complete. Commit
688e6c7258 introduced an rbtree so that only the earliest waiter on
the global timeline would woken, and would wake the next and so on.
(Along with various complications to handle requests being reordered
along the global timeline, and also a requirement for kthread to provide
a delegate for fence signaling that had no process context.)

The global rbtree depends on knowing the execution timeline (and global
seqno). Without knowing that order, we must instead check all contexts
queued to the HW to see which may have advanced. We trim that list by
only checking queued contexts that are being waited on, but still we
keep a list of all active contexts and their active signalers that we
inspect from inside the irq handler. By moving the waiters onto the fence
signal list, we can combine the client wakeup with the dma_fence
signaling (a dramatic reduction in complexity, but does require the HW
being coherent, the seqno must be visible from the cpu before the
interrupt is raised - we keep a timer backup just in case).

Having previously fixed all the issues with irq-seqno serialisation (by
inserting delays onto the GPU after each request instead of random delays
on the CPU after each interrupt), we can rely on the seqno state to
perfom direct wakeups from the interrupt handler. This allows us to
preserve our single context switch behaviour of the current routine,
with the only downside that we lose the RT priority sorting of wakeups.
In general, direct wakeup latency of multiple clients is about the same
(about 10% better in most cases) with a reduction in total CPU time spent
in the waiter (about 20-50% depending on gen). Average herd behaviour is
improved, but at the cost of not delegating wakeups on task_prio.

v2: Capture fence signaling state for error state and add comments to
warm even the most cold of hearts.
v3: Check if the request is still active before busywaiting
v4: Reduce the amount of pointer misdirection with list_for_each_safe
and using a local i915_request variable inside the loops
v5: Add a missing pluralisation to a purely informative selftest message.

References: 688e6c7258 ("drm/i915: Slaughter the thundering i915_wait_request herd")
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/20190129205230.19056-2-chris@chris-wilson.co.uk
2019-01-29 21:45:22 +00:00
Chris Wilson 3df0bd1919 drm/i915: Remove the intel_engine_notify tracepoint
The global seqno is defunct and so we have no meaningful indicator of
forward progress for an engine. You need to listen to the request
signaling tracepoints instead.

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/20190129205230.19056-1-chris@chris-wilson.co.uk
2019-01-29 21:45:21 +00:00
Ville Syrjälä 68e94f62cf drm/i915/tv: Bypass the vertical filter if possible
Let's switch the pipe into interlaced mode and switch off
the TV encoder vertical filter if the pipe vdisplay
matches the TV YSIZE exactly.

While I didn't measure it I presume this might reduce
the power consumption a little bit, and the pixel rate
is halved as the pipe will now fetching in interlaced
mode rather than in progressive mode (effectively the
same difference as between IF-ID vs. PF-ID pfit modes
on more modern hardware) so a bit easier on the memory
bandwidth.

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129141913.5515-2-ville.syrjala@linux.intel.com
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2019-01-29 23:27:31 +02:00
Ville Syrjälä addc80f0bb drm/i915/tv: Fix adjusted_mode dotclock for interlaced modes
intel_tv_mode_to_mode() assumes the pipe will be in progressive
fetch mode, and thus when programming the pipe into interlaced
mode we have to halve the calculated dotclock to get the correct
field duration.

This becomes more important when we start to program the pipe
into interlaced mode on i965gm as we depend on the timestamps
to get accurate frame counter values. Withot halving the clock
our guesstimated frame counter would tick at twice the expected
speed.

Cc: Imre Deak <imre.deak@intel.com>
Fixes: 690157f0a9 ("drm/i915/tv: Fix >1024 modes on gen3")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129141913.5515-1-ville.syrjala@linux.intel.com
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2019-01-29 23:26:39 +02:00
Ville Syrjälä 5a3db6f08a drm: Constify drm_color_lut_check()
drm_color_lut_check() doens't modify the passed in blob so
let's make it const.

Also s/uint32_t/u32/ while at it.

v2: Reduce line wraps (Sam)

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129170609.5718-1-ville.syrjala@linux.intel.com
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2019-01-29 23:26:12 +02:00
Chris Wilson c9a6462288 drm/i915/execlists: Suppress preempting self
In order to avoid preempting ourselves, we currently refuse to schedule
the tasklet if we reschedule an inflight context. However, this glosses
over a few issues such as what happens after a CS completion event and
we then preempt the newly executing context with itself, or if something
else causes a tasklet_schedule triggering the same evaluation to
preempt the active context with itself.

However, when we avoid preempting ELSP[0], we still retain the preemption
value as it may match a second preemption request within the same time period
that we need to resolve after the next CS event. However, since we only
store the maximum preemption priority seen, it may not match the
subsequent event and so we should double check whether or not we
actually do need to trigger a preempt-to-idle by comparing the top
priorities from each queue. Later, this gives us a hook for finer
control over deciding whether the preempt-to-idle is justified.

The sequence of events where we end up preempting for no avail is:

1. Queue requests/contexts A, B
2. Priority boost A; no preemption as it is executing, but keep hint
3. After CS switch, B is less than hint, force preempt-to-idle
4. Resubmit B after idling

v2: We can simplify a bunch of tests based on the knowledge that PI will
ensure that earlier requests along the same context will have the highest
priority.
v3: Demonstrate the stale preemption hint with a selftest

References: a2bf92e8cc ("drm/i915/execlists: Avoid kicking priority on the current context")
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/20190129185452.20989-4-chris@chris-wilson.co.uk
2019-01-29 20:00:05 +00:00
Chris Wilson 4d97cbe019 drm/i915: Rename execlists->queue_priority to queue_priority_hint
After noticing that we trigger preemption events for currently executing
requests, as well as requests that complete before the preemption and
attempting to suppress those preemption events, it is wise to not
consider the queue_priority to be authoritative. As we only track the
maximum priority seen between dequeue passes, if the maximum priority
request is no longer available for dequeuing (it completed or is even
executing on another engine), we have no knowledge of the previous
queue_priority as it would require us to keep a full history of enqueued
requests -- but we already have that history in the priolists!

Rename the queue_priority to queue_priority_hint so that we do not
confuse it as being exactly the maximum priority in the queue, but merely
an indication that we have seen a new maximum priority value and as such
we should check whether it should preempt the currently running request.

v2: s/preempt_priority_hint/queue_priority_hint/ as preempt implies it
being only used for the singular task of preemption and not the wider
question of waking up due to a change in the queue.

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/20190129185452.20989-3-chris@chris-wilson.co.uk
2019-01-29 20:00:03 +00:00
Chris Wilson 8547444137 drm/i915: Identify active requests
To allow requests to forgo a common execution timeline, one question we
need to be able to answer is "is this request running?". To track
whether a request has started on HW, we can emit a breadcrumb at the
beginning of the request and check its timeline's HWSP to see if the
breadcrumb has advanced past the start of this request. (This is in
contrast to the global timeline where we need only ask if we are on the
global timeline and if the timeline has advanced past the end of the
previous request.)

There is still confusion from a preempted request, which has already
started but relinquished the HW to a high priority request. For the
common case, this discrepancy should be negligible. However, for
identification of hung requests, knowing which one was running at the
time of the hang will be much more important.

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/20190129185452.20989-2-chris@chris-wilson.co.uk
2019-01-29 19:59:59 +00:00