Buffer based command transport can replace MMIO based mechanism.
It may be used to perform host-2-guc and guc-to-host communication.

Portions of this patch are based on work by:
 Michel Thierry <michel.thierry@intel.com>
 Robert Beckett <robert.beckett@intel.com>
 Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>

v2: use gem_object_pin_map (Chris)
    don't use DEBUG_RATELIMITED (Chris)
    don't track action stats (Chris)
    simplify next fence (Chris)
    use READ_ONCE (Chris)
    move blob allocation to new function (Chris)

v3: use static owner id (Daniele)
v4: but keep channel initialization generic (Daniele)
    and introduce owner_sub_id (Daniele)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170526111326.87280-3-michal.wajdeczko@intel.com

In earlier patch 789a6251 we were enabling send function only
after successful init. For completeness, we should make sure
that we disable it on fini.

v2: don't group steps by submission flag (Chris)
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170526111326.87280-2-michal.wajdeczko@intel.com

This patch adds the following definition
- Bit mask for EDP_PWMGEN_BIT_COUNT and min/max cap
  register which only use bit 0:4
- Base frequency (27 MHz) for backlight PWM frequency
  generator.
Signed-off-by: NPuthikorn Voravootivat <puthik@chromium.org>
Reviewed-by: NDhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170523223805.46372-5-puthik@chromium.org

There are some panel that
(1) does not support display backlight enable via AUX
(2) support display backlight adjustment via AUX
(3) support display backlight enable via eDP BL_ENABLE pin

The current driver required that (1) must be support to enable (2).
This patch drops that requirement.
Signed-off-by: NPuthikorn Voravootivat <puthik@chromium.org>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170523223805.46372-2-puthik@chromium.org

We depend on intel_iommu_gfx_mapped for various workarounds, but that is
only available under an #ifdef CONFIG_INTEL_IOMMU. Refactor all the
cut-and-paste ifdefs to a common routine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170525121612.2190-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

As only GGTT vma may be permanently pinned and are always at the head of
the object's vma list, as soon as we seen a ppGTT vma we can stop
searching for any_vma_pinned().
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170525072528.11185-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

BXT has a H/W issue with IOMMU which can lead to system hangs when
Aperture accesses are queued within the GAM behind GTT Accesses.

This patch avoids the condition by wrapping all GTT updates in stop_machine
and using a flushing read prior to restarting the machine.

The stop_machine guarantees no new Aperture accesses can begin while
the PTE writes are being emmitted. The flushing read ensures that
any following Aperture accesses cannot begin until the PTE writes
have been cleared out of the GAM's fifo.

Only FOLLOWING Aperture accesses need to be separated from in flight
PTE updates. PTE Writes may follow tightly behind already in flight
Aperture accesses, so no flushing read is required at the start of
a PTE update sequence.

This issue was reproduced by running
	igt/gem_readwrite and
	igt/gem_render_copy
simultaneously from different processes, each in a tight loop,
with INTEL_IOMMU enabled.

This patch was originally published as:
	drm/i915: Serialize GTT Updates on BXT

v2: Move bxt/iommu detection into static function
    Remove #ifdef CONFIG_INTEL_IOMMU protection
    Make function names more reflective of purpose
    Move flushing read into static function

v3: Tidy up for checkpatch.pl

Testcase: igt/gem_concurrent_blit
Signed-off-by: NJon Bloomfield <jon.bloomfield@intel.com>
Cc: John Harrison <john.C.Harrison@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1495641251-30022-1-git-send-email-jon.bloomfield@intel.comReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Having just watched someone add a new value, 0x3, without realising that
the flags were bit values, I have come to appreciate the value in using
BIT.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170523103116.32239-1-chris@chris-wilson.co.ukReviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

The compiler doesn't always spot the guard that object is allocated on
the first pass, leading to:

drivers/gpu/drm/i915/selftests/i915_gem_context.c: warning: 'obj' may be used uninitialized in this function [-Wuninitialized]:  => 370:8

v2: Make it more obvious by setting obj to NULL on the first pass and
any later pass where we need to reallocate.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Fixes: 791ff39a ("drm/i915: Live testing for context execution")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
c: <drm-intel-fixes@lists.freedesktop.org> # v4.12-rc1+
Link: http://patchwork.freedesktop.org/patch/msgid/20170523194412.1195-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

If port[0] is occupied and we're trying to dequeue request from
different context, we will inevitably hit BUG_ON in port_assign.
Let's skip it - similar to what we're doing in execlists counterpart.

Fixes: 77f0d0e9 ("drm/i915/execlists: Pack the count into the low bits of the port.request")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NMichał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170523102400.9614-2-michal.winiarski@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Passing NULL ctx to request_alloc would lead to null-ptr-deref.

v2: Let's not replace the comment with a BUG_ON
Signed-off-by: NMichał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170523102400.9614-1-michal.winiarski@intel.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We improved the reset reliablity on gen4 with
stopping all engines before commencing reset, in
commit 2c80353f ("drm/i915/g4x: Improve gpu reset reliability")

Evidence indicates that this same trick works with g33.

v2: proper gen naming, comment readability (Chris)

Testcase: igt/gem_busy/*-hang #blb-e6850
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170522090244.2557-1-mika.kuoppala@intel.com

This reverts commit bc5ca47c.

Gabriel put this back into generic code with

commit 75f6dfe3
Author: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Date:   Wed Dec 28 12:32:11 2016 -0200

    drm: Deduplicate driver initialization message

but somehow he missed Chris' patch to add the message meanwhile.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101025
Fixes: 75f6dfe3 ("drm: Deduplicate driver initialization message")
Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: <stable@vger.kernel.org> # v4.11+
Reviewed-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517131557.7836-1-daniel.vetter@ffwll.ch

Update version of HuC from 01.07.1748 to the
version 02.00.1748

Cc: Ander Conselvan <ander.conselvan.de.oliveira@intel.com>
Cc: John Spotswood <john.a.spotswood@intel.com>
Signed-off-by: NAnusha Srivatsa <anusha.srivatsa@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1495129631-2930-1-git-send-email-anusha.srivatsa@intel.com

The memory allocation for C is not being null checked and hence we
could end up with a null pointer dereference. Fix this with a null
pointer check. (I really should have noticed this when I was fixing an
earlier issue.)

Detected by CoverityScan, CID#1436406 ("Dereference null return")

Fixes: 47624cc3 ("drm/i915: Import the kfence selftests for i915_sw_fence")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519175617.7036-1-colin.king@canonical.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Usefulness of these stats was over-advertised.

v2: remove duplicated engine stats (Chris)
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515170610.35528-1-michal.wajdeczko@intel.comAcked-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

ELK seems to very picky about the preconditions to reset.
Evidence on Eaglelake (8086:2e12 (rev 03)) shows that it does
not like if reset occurs when there is active ring.

Ville found out that there is workaround with name
'WaMediaResetMainRingCleanup' which suggests that we need to
cleanup rings before resetting. It is unclear what cleanup
exactly means but evidence shows that stopping the ring
does have an effect on reset reliability. This patch makes
reset successful on hangs induced by chained batches (the igt ones).
Note that if the hang is inside a shader, it is possible
that our attempts to stop the ring achieves anything.

v2: zero ctl,head,tail also. bug ref. use driver debugs (Chris)
v3: specify platform on testcases, comment tidyup (Chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100942
Testcase: igt/gem_busy/*-hang #elk
Testcase: igt/gem_ringfill/hang-* #elk
Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tomi Sarvela <tomi.p.sarvela@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519091340.21439-1-mika.kuoppala@intel.com

Debugfs does not seems to be a right place to display transient data.
If we want to capture errors, we should log them.
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518113104.54400-3-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This stat is almost always zero unless fatal error occurs,
which should be reported by other means anyway.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518113104.54400-2-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This member was dropped long time ago.

Fixes: 774439e1 ("drm/i915/guc: re-optimise i915_guc_client layout")
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518113104.54400-1-michal.wajdeczko@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Ville found a reference to WaMediaResetBeforeFullReset which we presume
means that we should simply do the media reset first.

References: https://bugs.freedesktop.org/show_bug.cgi?id=100942Suggested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518204811.7408-2-chris@chris-wilson.co.uk

Repeat the reset a couple of times if at first we do not succeed.

v2: differentiate which path/engine failed with a debug message
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170513083726.502-1-chris@chris-wilson.co.ukReviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518204811.7408-1-chris@chris-wilson.co.uk

Set the class on our mock pci device to GFX. This should be useful for
utilities like intel-iommu that special case gfx devices.

References: https://bugs.freedesktop.org/show_bug.cgi?id=101080Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518094638.5469-1-chris@chris-wilson.co.ukReviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

There are two occasions where pointer B is being check for a NULL
when it should be pointer C instead. Fix these.

Detected by CoverityScan, CID#1436348,1436349 ("Logically Dead Code")

Fixes: 47624cc3 ("drm/i915: Import the kfence selftests for i915_sw_fence")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518133942.5660-1-colin.king@canonical.comSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This commit fixes the following compiler warning:

drivers/gpu/drm/i915/intel_dsi.c: In function ‘intel_dsi_prepare’:
drivers/gpu/drm/i915/intel_dsi.c:1487:23: warning:
    ?: using integer constants in boolean context [-Wint-in-bool-context]
       PORT_A ? PORT_C : PORT_A),

Fixes: f4c3a88e ("drm/i915: Tighten mmio arrays for MIPI_PORT")
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518110644.9902-1-hdegoede@redhat.com

This patch make changes to use linetime latency if allocated
DDB size during plane watermark calculation is not available.
linetime is the time, display engine takes to fetch one line worth of
pixels with given pixel clock rate.
This is required to implement new DDB allocation algorithm.

In New Algorithm DDB is allocated based on WM values, because of which
number of DDB blocks will not be available during WM calculation,
So this "linetime latency" is suggested by SV/HW team to be used during
switch-case for WM blocks selection.
linetime latency us = pipe horizontal total pixels/adjusted pixel rate MHz

Changes since v1:
 - Rebase on top of Paulo's patch series
Changes since v2:
 - Fix if-else condition (pointed by Maarten)
Changes since v3:
 - Use common function for timetime_us calculation (Paulo)
 - rebase on drm-tip
Changes since v4:
 - Use consistent name for fixed_point operation
Changes since v5:
 - Improve commit message
 - rename skl_get_linetime_us to intel_get_linetime_us
 - fix watermark result selection (Matt)
Signed-off-by: N"Mahesh Kumar" <mahesh1.kumar@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-11-mahesh1.kumar@intel.com

Instead of iterating over planes & wm levels in a single function use
skl_compute_wm_level function to interate over WM levels.
Change name of function to skl_compute_wm_levels (Matt).

These changes are to clean-up WM code & will help in making only new
ddb algorithm related changes in later patch in series.
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-10-mahesh1.kumar@intel.com

This patch cleanup/reorganises the watermark calculation functions.
This patch make use of already available macro
"drm_atomic_crtc_state_for_each_plane_state" to walk through
plane_state list instead of calculating plane_state in function itself.

This restructuring will help later patch for new DDB allocation
algorithm to do only algo related changes.

Changes from V1:
 - split the patch in two parts as per Matt's comment
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-9-mahesh1.kumar@intel.com

DDB minimum requirement of crtc configuration (cumulative of all the
enabled planes in crtc) may exceed the allocated DDB for crtc/pipe.
This patch make changes to fail the flip/ioctl if minimum requirement
for pipe exceeds the total ddb allocated to the pipe.
Previously it succeeded but making alloc_size a negative value. Which
will make subsequent calculations for plane ddb allocation bogus & may
lead to screen corruption or system hang.

Changes from V1:
 - Improve commit message as per Ander's comment
 - Remove extra parentheses (Ander)
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NAnder Conselvan de Oliveira <conselvan2@gmail.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-8-mahesh1.kumar@intel.com

We are already doing memset of ddb structure at the begining of skl_allocate_pipe_ddb
function, No need to again do a memset.
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-7-mahesh1.kumar@intel.com

Fail the flip if no FB is present but plane_state is set as visible.
Above is not a valid combination so instead of continue fail the flip.
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-6-mahesh1.kumar@intel.com

This patch make changes to calculate adjusted plane pixel rate &
plane downscale amount using fixed_point functions available.
This patch will give uniformity in code, & will help to avoid mixing of
32bit uint32_t variable for fixed-16.16 with fixed_16_16_t variables in
later patch in the series.

Changes from V1:
 - Rebase based on wrapper name change
 - Remove unnecessary comment
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-5-mahesh1.kumar@intel.com

Don't use fixed_16_16 structure members directly, instead use wrapper to
perform fixed_16_16 division operation.
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-4-mahesh1.kumar@intel.com

This patch adds few wrapper to perform fixed_point_16_16 operations
mul_round_up_u32_fixed16 : Multiplies u32 and fixed_16_16_t variables
			   & returns u32 result with rounding-up.
mul_fixed16 : Multiplies two fixed_16_16_t variable & returns fixed_16_16
div_round_up_fixed16 : Perform division operation on fixed_16_16_t
		       variables & return u32 result with round-off
div_round_up_u32_fixed16 : devide uint32_t variable by fixed_16_16 variable
			   and round_up the result to uint32_t.

These wrappers will be used by later patches in the series.

Changes from V1:
 - Rename wrapper as per Matt's comment
Changes from V2:
 - Fix indentation
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-3-mahesh1.kumar@intel.com

fixed_16_16_div_round_up(_u64), wrapper for fixed_16_16 division
operation don't really round_up the result. Wrapper round_up only the
fraction part of the result to make it 16-bit.
This patch eliminates round_up keyword from the wrapper.

Later patch will introduce the new wrapper to do rounding-off the result
and give unt32_t output to cleanup mix use of fixed_16_16_t & uint32_t
variables.
Signed-off-by: NMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NMatt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-2-mahesh1.kumar@intel.com

Since we coordinate with the execlists tasklet using a locked schedule
operation that ensures that after we set the engine->irq_posted we
always have an invocation of the tasklet, we do not need to use a locked
operation to set the engine->irq_posted itself.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-12-chris@chris-wilson.co.uk

As the handler is now quite complex, involving a few atomics, the cost
of the function preamble is negligible in comparison and so we should
leave the function out-of-line for better I$.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-11-chris@chris-wilson.co.uk

If we do not require to perform priority bumping, and we haven't yet
submitted the request, we can update its priority in situ and skip
acquiring the engine locks -- thus avoiding any contention between us
and submit/execute.

v2: Remove the stack element from the list if we can do the early
assignment.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-10-chris@chris-wilson.co.uk

The i915_priolist are allocated within an atomic context on a path where
we wish to minimise latency. If we use a dedicated kmem_cache, we have
the advantage of a local freelist from which to service new requests
that should keep the latency impact of an allocation small. Though
currently we expect the majority of requests to be at default priority
(and so hit the preallocate priolist), once userspace starts using
priorities they are likely to use many fine grained policies improving
the utilisation of a private slab.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-9-chris@chris-wilson.co.uk

All the requests at the same priority are executed in FIFO order. They
do not need to be stored in the rbtree themselves, as they are a simple
list within a level. If we move the requests at one priority into a list,
we can then reduce the rbtree to the set of priorities. This should keep
the height of the rbtree small, as the number of active priorities can not
exceed the number of active requests and should be typically only a few.

Currently, we have ~2k possible different priority levels, that may
increase to allow even more fine grained selection. Allocating those in
advance seems a waste (and may be impossible), so we opt for allocating
upon first use, and freeing after its requests are depleted. To avoid
the possibility of an allocation failure causing us to lose a request,
we preallocate the default priority (0) and bump any request to that
priority if we fail to allocate it the appropriate plist. Having a
request (that is ready to run, so not leading to corruption) execute
out-of-order is better than leaking the request (and its dependency
tree) entirely.

There should be a benefit to reducing execlists_dequeue() to principally
using a simple list (and reducing the frequency of both rbtree iteration
and balancing on erase) but for typical workloads, request coalescing
should be small enough that we don't notice any change. The main gain is
from improving PI calls to schedule, and the explicit list within a
level should make request unwinding simpler (we just need to insert at
the head of the list rather than the tail and not have to make the
rbtree search more complicated).

v2: Avoid use-after-free when deleting a depleted priolist

v3: Michał found the solution to handling the allocation failure
gracefully. If we disable all priority scheduling following the
allocation failure, those requests will be executed in fifo and we will
ensure that this request and its dependencies are in strict fifo (even
when it doesn't realise it is only a single list). Normal scheduling is
restored once we know the device is idle, until the next failure!
Suggested-by: NMichał Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NMichał Winiarski <michal.winiarski@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517121007.27224-8-chris@chris-wilson.co.uk