We can convert engine stats from a spinlock to seqlock to ensure interrupt
processing is never even a tiny bit delayed by parallel readers.
There is a smidgen bit more cost on the write lock side, and an extremely
unlikely chance that readers will have to retry a few times in face of
heavy interrupt load. But it should be extremely unlikely given how
lightweight read side section is compared to the interrupt processing
side, and also compared to the rest of the code paths which can lead into
it. Furthermore, writer is the ones doing the real, latency sensitive
work, while readers are only informative.
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/20180426074716.7352-1-tvrtko.ursulin@linux.intel.com
Instead of synchronously cancelling the timer and re-enabling it inside
the reset callbacks, keep the timer enabled and let it die on its next
wakeup if no longer required. This allows
intel_engine_reset_breadcrumbs() to be used from an atomic
(timer/softirq) context such as required for resetting an engine.
It also allows us to react better to the user poking around debugfs for
testing missed irqs.
v2: Tighten the order of del_timer_sync as the fake_irq timer
may trigger the hangcheck timer, and so we should cancel it first and
then cancel the hangcheck (Mika)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180424142945.6787-1-chris@chris-wilson.co.uk
If we have more than a few, possibly several thousand request in the
queue, don't show the central portion, just the first few and the last
being executed and/or queued. The first few should be enough to help
identify a problem in execution, and most often comparing the first/last
in the queue is enough to identify problems in the scheduling.
We may need some fine tuning to set MAX_REQUESTS_TO_SHOW for common
debug scenarios, but for the moment if we can avoiding spending more
than a few seconds dumping the GPU state that will avoid a nasty
livelock (where hangcheck spends so long dumping the state, it fires
again and starts to dump the state again in parallel, ad infinitum).
v2: Remember to print last not the stale rq iter after the loop.
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/20180424081600.27544-1-chris@chris-wilson.co.uk
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Addresses-Coverity-ID: 1466154 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
For perfomance purpose, scanning of non-privileged batch buffer is turned
off by default. But for debugging purpose, it can be turned on via debugfs.
After scanning, we submit the original non-privileged batch buffer into
hardware, so that the scanning is only a peeking window of guest submitted
commands and will not affect the execution results.
v4:
- refine debugfs print format&content (zhenyu wang)
- print engine id instread of engine name to prevent potential memory leak
in debugfs warning message. (zhenyu wang)
v3:
- change vgpu->scan_nonprivbb from type bool to u32, so it is able to
selectively turn on/off scanning of non-privileged batch buffer on engine
level. e.g.
if vgpu->scan_nonprivbb=3, then it will scan non-privileged batch buffer
on engine 0 and 1.
- in debugfs interface to set vgpu->scan_nonprivbb, print warning message
to warn user and explicitly tell state change in kernel log (zhenyu wang)
v2:
- rebase
- update comments for start_gma_offset (henry)
Signed-off-by: Zhao Yan <yan.y.zhao@intel.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
When there is only one vGPU in GVT-g and it submits workloads
continuously, it will not be scheduled out, vgpu_update_timeslice
is not called and its sched_in_time is not updated in a long time,
which can be several seconds or longer.
Once GVT-g pauses to submit workload for this vGPU due to heavy
host CPU workload, this vGPU get scheduled out and
vgpu_update_timeslice is called, its left_ts will be subtract
by a big value from sched_out_time - sched_in_time.
When GVT-g is going to submit workload for this vGPU again,
it will not be scheduled in until gvt_balance_timeslice reaches
stage 0 and reset its left_ts, which introduces several
hunderand milliseconds latency.
This patch updates time slice in every ms to update sched_in_time
timely.
v2: revise commit message
v3: use more concise expr. (Zhenyu)
Signed-off-by: Zhipeng Gong <zhipeng.gong@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Min He <min.he@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
intel_gvt_schedule check timer through a counter and is supposed
to wake up to increase the counter every ms.
In a system with heavy workload, gvt_service_thread can not get
a chance to run right after wake up and will be delayed several
milliseconds. As a result, one hundred counter interval means
several hundred milliseconds in real time.
This patch use real time instead of counter to do timer check.
v2: remove static variable. (Zhenyu)
v3: correct expire_time update. (Zhenyu)
Signed-off-by: Zhipeng Gong <zhipeng.gong@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Min He <min.he@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Before this commit the WaSkipStolenMemoryFirstPage workaround code was
skipping the first 4k by passing 4096 as start of the address range passed
to drm_mm_init(). This means that calling drm_mm_reserve_node() to try and
reserve the firmware framebuffer so that we can inherit it would always
fail, as the firmware framebuffer starts at address 0.
Commit d435376104 ("drm/i915: skip the first 4k of stolen memory on
everything >= gen8") says in its commit message: "This is confirmed to fix
Skylake screen flickering issues (probably caused by the fact that we
initialized a ring in the first page of stolen, but I didn't 100% confirm
this theory)."
Which suggests that it is safe to use the first page for a linear
framebuffer as the firmware is doing (see note below).
This commit always passes 0 as start to drm_mm_init() and works around
WaSkipStolenMemoryFirstPage in i915_gem_stolen_insert_node_in_range()
by insuring the start address passed by to drm_mm_insert_node_in_range()
is always 4k or more. All entry points to i915_gem_stolen.c go through
i915_gem_stolen_insert_node_in_range(), so that any newly allocated
objects such as ring-buffers will not be allocated in the first 4k.
The one exception is i915_gem_object_create_stolen_for_preallocated()
which directly calls drm_mm_reserve_node() which now will be able to
use the first 4k.
This fixes the i915 driver no longer being able to inherit the firmware
framebuffer on gen8+, which fixes the video output changing from the
vendor logo to a black screen as soon as the i915 driver is loaded
(on systems without fbcon).
Some notes about the mapping of the BIOS framebuffer:
v1 led to some discussion if the assumption of the intel_display.c code
that the firmware framebuffer is a linear mapping of the stolen memory
starting at offset 0 is still correct, because that would mean that the
GOP does not implement the WaSkipStolenMemoryFirstPage workaround.
To verify this the following code was added at the end of
i915_gem_object_create_stolen_for_preallocated() :
pr_err("first ggtt entry before bind: 0x%016llx\n",
readq(dev_priv->ggtt.gsm));
ret = i915_vma_bind(vma,
HAS_LLC(dev_priv) ? I915_CACHE_LLC : I915_CACHE_NONE,
PIN_UPDATE);
pr_err("i915_vma_bind ret %d\n", ret);
pr_err("first ggtt entry after bind: 0x%016llx\n",
readq(dev_priv->ggtt.gsm));
Which prints the mapping of the first page, then does a vma_bind() to
force update the mapping with our linear view of the framebuffer and
then prints the mapping of the first page again.
On an Asrock B150M Pro4S/D3 mainboard with i5-6500 CPU this prints:
[ 1.651141] first ggtt entry before bind: 0x0000000078c00001
[ 1.651151] i915_vma_bind ret 0
[ 1.651152] first ggtt entry after bind: 0x0000000078c00083
And "sudo cat /proc/iomem | grep Stolen" gives:
78c00000-88bfffff : Graphics Stolen Memory
There are no visual changes with this patch (BIOS vendor logo still
stays in place when we inherit the BIOS framebuffer), so the vma_bind()
does not impact which memory is being scanned out.
The address of the first ggtt entry matches with the start of stolen
and the i915_vma_bind call only changes the first gtt entry's flags,
or-ing in _PAGE_RW (BIT(1)) and PPAT_CACHED (BIT(7)), which perfectly
matches what we would expect based on gen8_pte_encode()'s behavior.
So it seems that the GOP indeed does NOT implement the wa and the i915's
code assuming a linear mapping at the start of stolen for the BIOS fb
still holds true for gen8+.
I've also tested this on a Cherry Trail based device (a GPD Win)
with identical results (the flags are 0x1b after the vma_bind
on CHT, which matches with I915_CACHE_NONE).
Changed in v2: No code changes, extended the commit message with the
verification that the intel_display.c BIOS framebuffer mapping is still
correct.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180420095933.16442-1-hdegoede@redhat.com
Interrupts other than the one for AUX errors are required only for debug,
so unmask them via debugfs when the user requests debug.
User can make such a request with
echo 1 > <DEBUG_FS>/dri/0/i915_edp_psr_debug
There are no locks to serialize PSR debug enabling from
irq_postinstall() and debugfs for simplicity. As irq_postinstall() is
called only during module initialization/resume and IGT subtests
aren't expected to modify PSR debug at those times, we should be safe.
v2: Unroll loops (Ville)
Avoid resetting error mask bits.
v3: Unmask interrupts in postinstall() if debug was still enabled.
Avoid RMW (Ville)
v4: Avoid extra IMR write introduced in the previous version.(Jose)
Style changes, renames (Jose).
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405013717.24254-1-dhinakaran.pandiyan@intel.com
Today we only want to pass along the priority to engine->schedule(), but
in the future we want to have much more control over the various aspects
of the GPU during a context's execution, for example controlling the
frequency allowed. As we need an ever growing number of parameters for
scheduling, move those into a struct for convenience.
v2: Move the anonymous struct into its own function for legibility and
ye olde gcc.
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/20180418184052.7129-3-chris@chris-wilson.co.uk
Add a selftest to ensure that we restore the whitelisted registers after
rewrite the registers everytime they might be scrubbed, e.g. module
load, reset and resume. For the other volatile workaround registers, we
export their presence via debugfs and check in igt/gem_workarounds.
However, we don't export the whitelist and rather than do so, let's test
them directly in the kernel.
The test we use is to read the registers back from the CS (this helps us
be sure that the registers will be valid for MI_LRI etc). In order to
generate the expected list, we split intel_whitelist_workarounds_emit
into two phases, the first to build the list and the second to apply.
Inside the test, we only build the list and then check that list against
the hw.
v2: Filter out pre-gen8 as they do not have RING_NONPRIV.
v3: Drop unused engine parameter, no plans to use it now or future.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Oscar Mateo <oscar.mateo@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180414122754.569-1-chris@chris-wilson.co.uk
There are different kind of workarounds (those that modify registers that
live in the context image, those that modify global registers, those that
whitelist registers, etc...) and they have different requirements in terms
of where they are applied and how. Also, by splitting them apart, it should
be easier to decide where a new workaround should go.
v2:
- Add multiple MISSING_CASE
- Rebased
v3:
- Rename mmio_workarounds to gt_workarounds (Chris, Mika)
- Create empty placeholders for BDW and CHV GT WAs
- Rebased
v4: Rebased
v5:
- Rebased
- FORCE_TO_NONPRIV register exists since BDW, so make a path
for it to achieve universality, even if empty (Chris)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[ickle: appease checkpatch]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1523376767-18480-2-git-send-email-oscar.mateo@intel.com
This has grown to be a sizable amount of code, so move it to
its own file before we try to refactor anything. For the moment,
we are leaving behind the WA BB code and the WAs that get applied
(incorrectly) in init_clock_gating, but we will deal with it later.
v2: Use intel_ prefix for code that deals with the hardware (Chris)
v3: Rebased
v4:
- Rebased
- New license header
v5:
- Rebased
- Added some organisational notes to the file (Chris)
v6: Include DOC section in the documentation build (Jani)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[ickle: appease checkpatch, mostly]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1523376767-18480-1-git-send-email-oscar.mateo@intel.com
We can refine our current execlists->queue_priority if we inspect
ELSP[1] rather than the head of the unsubmitted queue. Currently, we use
the unsubmitted queue and say that if a subsequent request is more
important than the current queue, we will rerun the submission tasklet
to evaluate the need for preemption. However, we only want to preempt if
we need to jump ahead of a currently executing request in ELSP. The
second reason for running the submission tasklet is amalgamate requests
into the active context on ELSP[0] to avoid a stall when ELSP[0] drains.
(Though repeatedly amalgamating requests into the active context and
triggering many lite-restore is off question gain, the goal really is to
put a context into ELSP[1] to cover the interrupt.) So if instead of
looking at the head of the queue, we look at the context in ELSP[1] we
can answer both of the questions more accurately -- we don't need to
rerun the submission tasklet unless our new request is important enough
to feed into, at least, ELSP[1].
v2: Add some comments from the discussion with Tvrtko.
v3: More commentary to cross-reference queue_request()
References: f6322eddaf ("drm/i915/preemption: Allow preemption between submission ports")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180411103929.27374-1-chris@chris-wilson.co.uk
While thinking about sporadic failures of perf_pmu/rc6-runtime-pm* tests
on some CI machines I have concluded that: a) the PMU readout of RC6 can
race against runtime PM transitions, and b) there are other reasons than
being runtime suspended which can cause intel_runtime_pm_get_if_in_use to
fail.
Therefore when estimating RC6 the code needs to assert we are indeed in
suspended state, and if not, the best we can do is return the last known
RC6 value.
Without this check we can calculate the estimated value based on un-
initialized or inappropriate internal state, which can result in over-
estimation, or in any case incorrect value being returned.
v2:
* Re-arrange the code a bit to avoid second unlock and return branch.
(Chris Wilson)
v3:
* Insert some strategic blank lines and improve commit msg.
(Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 1fe699e301 ("drm/i915/pmu: Fix sleep under atomic in RC6 readout")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105010
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180410112704.24462-1-tvrtko.ursulin@linux.intel.com
%phn is not a valid specifier, and the trailing 'n' is being eaten by
the format-specifier and defaulting to the ' ' separator. Avoid angering
smatch by using the unknown specifier, and use the default we expect.
drivers/gpu/drm/i915/intel_guc_ct.c:616 ctb_read() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:616 ctb_read() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:616 ctb_read() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:669 ct_handle_response() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:679 ct_handle_response() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:693 ct_handle_response() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:707 ct_handle_response() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:727 ct_process_request() warn: '%ph' cannot be followed by 'n'
drivers/gpu/drm/i915/intel_guc_ct.c:803 ct_handle_request() warn: '%ph' cannot be followed by 'n'
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180410111417.27563-1-chris@chris-wilson.co.uk
