drm/i915: Define and use GuC and CTB TLB invalidation routines

The GuC firmware had defined the interface for Translation Look-Aside
Buffer (TLB) invalidation. We should use this interface when
invalidating the engine and GuC TLBs.
Add additional functionality to intel_gt_invalidate_tlb, invalidating
the GuC TLBs and falling back to GT invalidation when the GuC is
disabled.
The invalidation is done by sending a request directly to the GuC
tlb_lookup that invalidates the table. The invalidation is submitted as
a wait request and is performed in the CT event handler. This means we
cannot perform this TLB invalidation path if the CT is not enabled.
If the request isn't fulfilled in two seconds, this would constitute
an error in the invalidation as that would constitute either a lost
request or a severe GuC overload.

With this new invalidation routine, we can perform GuC-based GGTT
invalidations. GuC-based GGTT invalidation is incompatible with
MMIO invalidation so we should not perform MMIO invalidation when
GuC-based GGTT invalidation is expected.

The additional complexity incurred in this patch will be necessary for
range-based tlb invalidations, which will be platformed in the future.

Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>
Signed-off-by: Bruce Chang <yu.bruce.chang@intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Signed-off-by: Fei Yang <fei.yang@intel.com>
CC: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231017180806.3054290-4-jonathan.cavitt@intel.com

drm/i915/guc: Enable WA 14018913170

The GuC handles the WA, the KMD just needs to set the flag to enable
it on the appropriate platforms.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231006013553.1339418-1-John.C.Harrison@Intel.com

drm/i915/guc: Remove some obsolete definitions

There were a bunch of defines and structures left over from an API
update a very long time ago. Remove them.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230531155942.441862-1-John.C.Harrison@Intel.com

drm/i915/guc: Fix confused register capture list creation

The GuC has a completely separate engine class enum when referring to
register capture lists, which combines render and compute. The driver
was using the 'normal' GuC specific engine class enum instead. That
meant that it thought it was defining a capture list for compute
engines, the list was actually being applied to the GSC engine. And if
a platform didn't have a render engine, then it would get no compute
register captures at all.

Fix that.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512013544.3367606-1-John.C.Harrison@Intel.com

drm/i915/guc: drop lots of kernel-doc markers

The documentation is closer to not being kernel-doc, so just drop the
kernel-doc markers.

drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:27: warning: Function parameter or member 'size' not described in '__guc_capture_bufstate'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:27: warning: Function parameter or member 'data' not described in '__guc_capture_bufstate'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:27: warning: Function parameter or member 'rd' not described in '__guc_capture_bufstate'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:27: warning: Function parameter or member 'wr' not described in '__guc_capture_bufstate'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'link' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'is_partial' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'eng_class' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'eng_inst' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'guc_id' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'lrca' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:59: warning: Function parameter or member 'reginfo' not described in '__guc_capture_parsed_output'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:62: warning: wrong kernel-doc identifier on line:
* struct guc_debug_capture_list_header / struct guc_debug_capture_list
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:80: warning: wrong kernel-doc identifier on line:
* struct __guc_mmio_reg_descr / struct __guc_mmio_reg_descr_group
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:105: warning: wrong kernel-doc identifier on line:
* struct guc_state_capture_header_t / struct guc_state_capture_t /
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:163: warning: Function parameter or member 'is_valid' not described in '__guc_capture_ads_cache'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:163: warning: Function parameter or member 'ptr' not described in '__guc_capture_ads_cache'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:163: warning: Function parameter or member 'size' not described in '__guc_capture_ads_cache'
drivers/gpu/drm/i915/gt/uc/guc_capture_fwif.h:163: warning: Function parameter or member 'status' not described in '__guc_capture_ads_cache'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'marker' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'read_ptr' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'write_ptr' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'size' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'sampled_write_ptr' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'wrap_offset' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'flush_to_file' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'buffer_full_cnt' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'reserved' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'flags' not described in 'guc_log_buffer_state'
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h:491: warning: Function parameter or member 'version' not described in 'guc_log_buffer_state'

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/9c210d53fdbd6da5fac42e435855d269504919d7.1683041799.git.jani.nikula@intel.com

drm/i915/mtl: pass the GSC CS info to the GuC

We need to tell the GuC that the GSC CS is there.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102171047.2787951-3-daniele.ceraolospurio@intel.com

drm/i915/guc: Limit scheduling properties to avoid overflow

GuC converts the pre-emption timeout and timeslice quantum values into
clock ticks internally. That significantly reduces the point of 32bit
overflow. On current platforms, worst case scenario is approximately
110 seconds. Rather than allowing the user to set higher values and
then get confused by early timeouts, add limits when setting these
values.

v2: Add helper functions for clamping (review feedback from Tvrtko).
v3: Add a bunch of BUG_ON range checks in addition to the checks
already in the clamping functions (Tvrtko)

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221006213813.1563435-2-John.C.Harrison@Intel.com

drm/i915/guc: Enable compute scheduling on DG2

DG2 has issues. To work around one of these the GuC must schedule
apps in an exclusive manner across both RCS and CCS. That is, if a
context from app X is running on RCS then all CCS engines must sit
idle even if there are contexts from apps Y, Z, ... waiting to run. A
certain OS favours RCS to the total starvation of CCS. Linux does not.
Hence the GuC now has a scheduling policy setting to control this
abitration.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220922201209.1446343-2-John.C.Harrison@Intel.com

drm/i915/guc: support v69 in parallel to v70

This patch re-introduces support for GuC v69 in parallel to v70. As this
is a quick fix, v69 has been re-introduced as the single "fallback" guc
version in case v70 is not available on disk and only for platforms that
are out of force_probe and require the GuC by default. All v69 specific
code has been labeled as such for easy identification, and the same was
done for all v70 functions for which there is a separate v69 version,
to avoid accidentally calling the wrong version via the unlabeled name.

When the fallback mode kicks in, a drm_notice message is printed in
dmesg to inform the user of the required update. The existing
logging of the fetch function has also been updated so that we no
longer complain immediately if we can't find a fw and we only throw an
error if the fetch of both the base and fallback blobs fails.

The plan is to follow this up with a more complex rework to allow for
multiple different GuC versions to be supported at the same time.

v2: reduce the fallback to platform that require it, switch to
firmware_request_nowarn(), improve logs.

Fixes: 2584b3549f4c ("drm/i915/guc: Update to GuC version 70.1.1")
Link: https://lists.freedesktop.org/archives/intel-gfx/2022-July/301640.html
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220718230732.1409641-1-daniele.ceraolospurio@intel.com

drm/i915: More PVC+DG2 workarounds

A new PVC+DG2 workaround has appeared recently:
- Wa_16015675438

And a couple existing DG2 workarounds have been extended to PVC:
- Wa_14015795083
- Wa_18018781329

Note that Wa_16015675438 asks us to program a register that is in the
0x2xxx range typically associated with the RCS engine, even though PVC
does not have an RCS. By default the GuC will think we've made a
mistake and throw an exception when it sees this register on a CCS
engine's save/restore list, so we need to pass an extra GuC control flag
to tell it that this is expected and not a problem.

Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220608005108.3717895-1-matthew.d.roper@intel.com

drm/i915/guc: support v69 in parallel to v70

This patch re-introduces support for GuC v69 in parallel to v70. As this
is a quick fix, v69 has been re-introduced as the single "fallback" guc
version in case v70 is not available on disk and only for platforms that
are out of force_probe and require the GuC by default. All v69 specific
code has been labeled as such for easy identification, and the same was
done for all v70 functions for which there is a separate v69 version,
to avoid accidentally calling the wrong version via the unlabeled name.

When the fallback mode kicks in, a drm_notice message is printed in
dmesg to inform the user of the required update. The existing
logging of the fetch function has also been updated so that we no
longer complain immediately if we can't find a fw and we only throw an
error if the fetch of both the base and fallback blobs fails.

The plan is to follow this up with a more complex rework to allow for
multiple different GuC versions to be supported at the same time.

v2: reduce the fallback to platform that require it, switch to
firmware_request_nowarn(), improve logs.

Fixes: 2584b3549f4c ("drm/i915/guc: Update to GuC version 70.1.1")
Link: https://lists.freedesktop.org/archives/intel-gfx/2022-July/301640.html
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220718230732.1409641-1-daniele.ceraolospurio@intel.com
(cherry picked from commit 774ce1510e6ccb9c0752d4aa7a9ff3624b3db3f3)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915/dg2: Enable Wa_22012727170/Wa_22012727685

The above two workaronuds regarding context isolation are implemented
by GuC. The KMD just needs to enable them.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-7-umesh.nerlige.ramappa@intel.com

drm/i915/dg2: Enable Wa_14014475959 - RCS / CCS context exit

There is bug in DG2 where if the CCS contexts switches out while the RCS
is running it can cause memory corruption. To workaround this add an
atomic to a memory address with a value 1 and semaphore wait to the same
address for a value of 0. The GuC firmware is responsible for writing 0
to the memory address when it is safe for the context to switch out.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-6-umesh.nerlige.ramappa@intel.com

drm/i915/guc: Apply Wa_16011777198

Enable GuC Wa to reset RCS/CCS before it goes into RC6.

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-5-umesh.nerlige.ramappa@intel.com

drm/i915/guc: Enable GuC based workarounds for DG2

There are some workarounds for DG2 that are implemented in the GuC
firmware. However, the KMD is required to enable these by setting the
appropriate flag as GuC does not know what platform it is running on.
Wa_16011759253
Wa_14012630569
Wa_14013746162

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
CC: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-4-umesh.nerlige.ramappa@intel.com

drm/i915/guc: Enable Wa_22011802037 for gen12 GuC based platforms

Initiating a reset when the command streamer is not idle or in the
middle of executing an MI_FORCE_WAKE can result in a hang. Multiple
command streamers can be part of a single reset domain, so resetting one
would mean resetting all command streamers in that domain.

To workaround this, before initiating a reset, ensure that all command
streamers within that reset domain are either IDLE or are not executing
a MI_FORCE_WAKE.

Enable GuC PRE_PARSER WA bit so that GuC follows the WA sequence when
initiating engine-resets.

For gt-resets, ensure that i915 applies the WA sequence.

Opens to address in future patches:
- The part of the WA to wait for pending forcewakes is also applicable
to execlists backend.
- The WA also needs to be applied for gen11

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220415224025.3693037-3-umesh.nerlige.ramappa@intel.com

drm/i915/guc: Update to GuC version 70.1.1

The latest GuC firmware drops the context descriptor pool in favour of
passing all creation data in the create H2G. It also greatly simplifies
the work queue and removes the process descriptor used for multi-LRC
submission. So, remove all mention of LRC and process descriptors and
update the registration code accordingly.

Unfortunately, the new API also removes the ability to set default
values for the scheduling policies at context registration time.
Instead, a follow up H2G must be sent. The individual scheduling
policy update H2G commands are also dropped in favour of a single KLV
based H2G. So, change the update wrappers accordingly and call this
during context registration..

Of course, this second H2G per registration might fail due to being
backed up. The registration code has a complicated state machine to
cope with the actual registration call failing. However, if that works
then there is no support for unwinding if a further call should fail.
Unwinding would require sending a H2G to de-register - but that can't
be done because the CTB is already backed up.

So instead, add a new flag to say whether the context has a pending
policy update. This is set if the policy H2G fails at registration
time. The submission code checks for this flag and retries the policy
update if set. If that call fails, the submission path early exists
with a retry error. This is something that is already supported for
other reasons.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220412225955.1802543-2-John.C.Harrison@Intel.com

drm/i915/guc: Add XE_LP static registers for GuC error capture.

Add device specific tables and register lists to cover different engines
class types for GuC error state capture for XE_LP products.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321164527.2500062-3-alan.previn.teres.alexis@intel.com

drm/i915/guc: Update GuC ADS size for error capture lists

Update GuC ADS size allocation to include space for
the lists of error state capture register descriptors.

Then, populate GuC ADS with the lists of registers we want
GuC to report back to host on engine reset events. This list
should include global, engine-class and engine-instance
registers for every engine-class type on the current hardware.

Ensure we allocate a persistent store for the register lists
that are populated into ADS so that we don't need to allocate
memory during GT resets when GuC is reloaded and ADS population
happens again.

NOTE: Start with a sample static table of register lists to
layout the framework before adding real registers in subsequent
patch. This static register tables are a different format from
the ADS populated list.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321164527.2500062-2-alan.previn.teres.alexis@intel.com

drm/i915/guc: add steering info to GuC register save/restore list

GuC has its own steering mechanism and can't use the default set by i915,
so we need to provide the steering information that the FW will need to
save/restore registers while processing an engine reset. The GUC
interface allows us to do so as part of the register save/restore list
and it requires us to specify the steering for all multicast register, even
those that would be covered by the default setting for cpu access. Given
that we do not distinguish between registers that do not need steering and
registers that are guaranteed to work the default steering, we set the
steering for all entries in the guc list that do not require a special
steering (e.g. mslice) to the default settings; this will cost us a few
extra writes during engine reset but allows us to keep the steering
logic simple.

Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220314234203.799268-3-matthew.d.roper@intel.com

drm/i915/guc: Better name for context id limit

The LRC descriptor pool is going away. So, stop using it as the limit
for how many context ids are available. Instead, size the pool
according to the number of contexts allowed. Note that this is just a
naming change, the actual limit is identical in value.

While at it, also update a kzalloc(sizeof()*count) to be a
kcalloc(count,size).

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302003357.4188363-4-John.C.Harrison@Intel.com

drm/i915/xehp: Define compute class and engine

Introduce a Compute Command Streamer (CCS), which has access to
the media and GPGPU pipelines (but not the 3D pipeline).

To begin with, define the compute class/engine common functions, based
on the existing render ones.

v2:
- Add kerneldoc for drm_i915_gem_engine_class since we're adding a new
element to it. (Daniel)
- Make engine class <-> guc class converters use lookup tables to make
it more clear/explicit how the IDs map. (Tvrtko)

v3:
- Don't update uapi for now; we'll just include the driver-internal
changes for the time being.

Bspec: 46167, 45544
Original-author: Michel Thierry
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> #v1
Link: https://patchwork.freedesktop.org/patch/msgid/20220301231549.1817978-2-matthew.d.roper@intel.com

drm/i915/guc: Update to GuC version 69.0.3

Update to the latest GuC release.

The latest GuC firmware introduces a number of interface changes:

GuC may return NO_RESPONSE_RETRY message for requests sent over CTB.
Add support for this reply and try resending the request again as a
new CTB message.

A KLV (key-length-value) mechanism is now used for passing
configuration data such as CTB management.

With the new KLV scheme, the old CTB management actions are no longer
used and are removed.

Register capture on hang is now supported by GuC. Full i915 support
for this will be added by a later patch. A minimum support of
providing capture memory and register lists is required though, so add
that in.

The device id of the current platform needs to be provided at init time.

The 'poll CS' w/a (Wa_22012773006) was blanket enabled by previous
versions of GuC. It must now be explicitly requested by the KMD. So,
add in the code to turn it on when relevant.

The GuC log entry format has changed. This requires adding a new field
to the log header structure to mark the wrap point at the end of the
buffer (as the buffer size is no longer a multiple of the log entry
size).

New CTB notification messages are now sent for some things that were
previously only sent via MMIO notifications.

Of these, the crash dump notification was not really being handled by
i915. It called the log flush code but that only flushed the regular
debug log and then only if relay logging was enabled. So just report
an error message instead.

The 'exception' notification was just being ignored completely. So add
an error message for that as well.

Note that in either the crash dump or the exception case, the GuC is
basically dead. The KMD will detect this via the heartbeat and trigger
both an error log (which will include the crash dump as part of the
GuC log) and a GT reset. So no other processing is really required.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220107000622.292081-3-John.C.Harrison@Intel.com

drm/i915/pmu: Connect engine busyness stats from GuC to pmu

With GuC handling scheduling, i915 is not aware of the time that a
context is scheduled in and out of the engine. Since i915 pmu relies on
this info to provide engine busyness to the user, GuC shares this info
with i915 for all engines using shared memory. For each engine, this
info contains:

- total busyness: total time that the context was running (total)
- id: id of the running context (id)
- start timestamp: timestamp when the context started running (start)

At the time (now) of sampling the engine busyness, if the id is valid
(!= ~0), and start is non-zero, then the context is considered to be
active and the engine busyness is calculated using the below equation

engine busyness = total + (now - start)

All times are obtained from the gt clock base. For inactive contexts,
engine busyness is just equal to the total.

The start and total values provided by GuC are 32 bits and wrap around
in a few minutes. Since perf pmu provides busyness as 64 bit
monotonically increasing values, there is a need for this implementation
to account for overflows and extend the time to 64 bits before returning
busyness to the user. In order to do that, a worker runs periodically at
frequency = 1/8th the time it takes for the timestamp to wrap. As an
example, that would be once in 27 seconds for a gt clock frequency of
19.2 MHz.

Note:
There might be an over-accounting of busyness due to the fact that GuC
may be updating the total and start values while kmd is reading them.
(i.e kmd may read the updated total and the stale start). In such a
case, user may see higher busyness value followed by smaller ones which
would eventually catch up to the higher value.

v2: (Tvrtko)
- Include details in commit message
- Move intel engine busyness function into execlist code
- Use union inside engine->stats
- Use natural type for ping delay jiffies
- Drop active_work condition checks
- Use for_each_engine if iterating all engines
- Drop seq locking, use spinlock at GuC level to update engine stats
- Document worker specific details

v3: (Tvrtko/Umesh)
- Demarcate GuC and execlist stat objects with comments
- Document known over-accounting issue in commit
- Provide a consistent view of GuC state
- Add hooks to gt park/unpark for GuC busyness
- Stop/start worker in gt park/unpark path
- Drop inline
- Move spinlock and worker inits to GuC initialization
- Drop helpers that are called only once

v4: (Tvrtko/Matt/Umesh)
- Drop addressed opens from commit message
- Get runtime pm in ping, remove from the park path
- Use cancel_delayed_work_sync in disable_submission path
- Update stats during reset prepare
- Skip ping if reset in progress
- Explicitly name execlists and GuC stats objects
- Since disable_submission is called from many places, move resetting
stats to intel_guc_submission_reset_prepare

v5: (Tvrtko)
- Add a trylock helper that does not sleep and synchronize PMU event
callbacks and worker with gt reset

v6: (CI BAT failures)
- DUTs using execlist submission failed to boot since __gt_unpark is
called during i915 load. This ends up calling the GuC busyness unpark
hook and results in kick-starting an uninitialized worker. Let
park/unpark hooks check if GuC submission has been initialized.
- drop cant_sleep() from trylock helper since rcu_read_lock takes care
of that.

v7: (CI) Fix igt@i915_selftest@live@gt_engines
- For GuC mode of submission the engine busyness is derived from gt time
domain. Use gt time elapsed as reference in the selftest.
- Increase busyness calculation to 10ms duration to ensure batch runs
longer and falls within the busyness tolerances in selftest.

v8:
- Use ktime_get in selftest as before
- intel_reset_trylock_no_wait results in a lockdep splat that is not
trivial to fix since the PMU callback runs in irq context and the
reset paths are tightly knit into the driver. The test that uncovers
this is igt@perf_pmu@faulting-read. Drop intel_reset_trylock_no_wait,
instead use the reset_count to synchronize with gt reset during pmu
callback. For the ping, continue to use intel_reset_trylock since ping
is not run in irq context.

- GuC PM timestamp does not tick when GuC is idle. This can potentially
result in wrong busyness values when a context is active on the
engine, but GuC is idle. Use the RING TIMESTAMP as GPU timestamp to
process the GuC busyness stats. This works since both GuC timestamp and
RING timestamp are synced with the same clock.

- The busyness stats may get updated after the batch starts running.
This delay causes the busyness reported for 100us duration to fall
below 95% in the selftest. The only option at this time is to wait for
GuC busyness to change from idle to active before we sample busyness
over a 100us period.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211027004821.66097-2-umesh.nerlige.ramappa@intel.com

drm/i915/guc: Implement no mid batch preemption for multi-lrc

For some users of multi-lrc, e.g. split frame, it isn't safe to preempt
mid BB. To safely enable preemption at the BB boundary, a handshake
between parent and child is needed, syncing the set of BBs at the
beginning and end of each batch. This is implemented via custom
emit_bb_start & emit_fini_breadcrumb functions and enabled by default if
a context is configured by set parallel extension.

Lastly, this patch updates the process descriptor to the correct size as
the memory used in the handshake is directly after the process
descriptor.

v2:
(John Harrison)
- Fix a few comments wording
- Add struture for parent page layout
v3:
(John Harrison)
- A structure for sync semaphore
- Use offsetof to calc address
- Update commit message
v4:
(John Harrison)
- Fix typos in comment explaining memory map of scratch page

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-20-matthew.brost@intel.com

drm/i915/guc: Implement multi-lrc submission

Implement multi-lrc submission via a single workqueue entry and single
H2G. The workqueue entry contains an updated tail value for each
request, of all the contexts in the multi-lrc submission, and updates
these values simultaneously. As such, the tasklet and bypass path have
been updated to coalesce requests into a single submission.

v2:
(John Harrison)
- s/wqe/wqi
- Use FIELD_PREP macros
- Add GEM_BUG_ONs ensures length fits within field
- Add comment / white space to intel_guc_write_barrier
(Kernel test robot)
- Make need_tasklet a static function
v3:
(Docs)
- A comment for submission_stall_reason
v4:
(Kernel test robot)
- Initialize return value in bypass tasklt submit function
(John Harrison)
- Add comment near work queue defs
- Add BUILD_BUG_ON to ensure WQ_SIZE is a power of 2
- Update write_barrier comment to talk about work queue
v5:
(John Harrison)
- Fix typo in work queue comment

Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-13-matthew.brost@intel.com

drm/i915/guc: Add multi-lrc context registration

Add multi-lrc context registration H2G. In addition a workqueue and
process descriptor are setup during multi-lrc context registration as
these data structures are needed for multi-lrc submission.

v2:
(John Harrison)
- Move GuC specific fields into sub-struct
- Clean up WQ defines
- Add comment explaining math to derive WQ / PD address
v3:
(John Harrison)
- Add PARENT_SCRATCH_SIZE define
- Update comment explaining multi-lrc register
v4:
(John Harrison)
- Move PARENT_SCRATCH_SIZE to common file

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-9-matthew.brost@intel.com

drm/i915/guc/slpc: Adding SLPC communication interfaces

Add constants and params that are needed to configure SLPC.

v2: Add a new abi header for SLPC. Replace bitfields with
genmasks. Address other comments from Michal W.

v3: Add slpc H2G format in abi, other review commments (Michal W)

v4: Update status bits according to latest spec

v5: checkpatch()

Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Sundaresan Sujaritha <sujaritha.sundaresan@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730202119.23810-4-vinay.belgaumkar@intel.com

drm/i915/guc: Ensure G2H response has space in buffer

Ensure G2H response has space in the buffer before sending H2G CTB as
the GuC can't handle any backpressure on the G2H interface.

v2:
(Matthew)
- s/INTEL_GUC_SEND/INTEL_GUC_CT_SEND
v3:
(Matthew)
- Add G2H credit accounting to blocking path, add g2h_release_space
helper
(John H)
- CTB_G2H_BUFFER_SIZE / 4 == G2H_ROOM_BUFFER_SIZE

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-15-matthew.brost@intel.com

drm/i915/guc: Remove GuC stage descriptor, add LRC descriptor

Remove old GuC stage descriptor, add LRC descriptor which will be used
by the new GuC interface implemented in this patch series.

v2:
(John Harrison)
- s/lrc/LRC/g

Cc: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-3-matthew.brost@intel.com

drm/i915/guc: Add new GuC interface defines and structures

Add new GuC interface defines and structures while maintaining old ones
in parallel.

Cc: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-2-matthew.brost@intel.com

drm/i915/guc: Update firmware to v62.0.0

Most of the changes to the 62.0.0 firmware revolved around CTB
communication channel. Conform to the new (stable) CTB protocol.

v2:
(Michal)
Add values back to kernel DOC for actions
(Docs)
Add 'CT buffer' back in to fix warning

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
[mattrope: Tweaked kerneldoc while pushing as suggested by Daniele/Michal]
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210616001302.84233-3-matthew.brost@intel.com

drm/i915/guc: Use guc_class instead of engine_class in fw interface

GuC has its own defines for the engine classes. They're currently
mapping 1:1 to the defines used by the driver, but there is no guarantee
this will continue in the future. Given that we've been caught off-guard
in the past by similar divergences, we can prepare for the changes by
introducing helper functions to convert from engine class to GuC class and
back again.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210603051630.2635-21-matthew.brost@intel.com

drm/i915/guc: Keep strict GuC ABI definitions

Our fwif.h file is now mix of strict firmware ABI definitions and
set of our helpers. In anticipation of upcoming changes to the GuC
interface try to keep them separate in smaller maintainable files.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210603051630.2635-6-matthew.brost@intel.com

drm/i915/guc: Remove sample_forcewake h2g action

This action is no-op in the GuC side for a few versions already
and it is getting entirely removed soon, in an upcoming version.

Time to remove before we face communication issues.

Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210603051630.2635-5-matthew.brost@intel.com

drm/i915/guc: Update to use firmware v49.0.1

The latest GuC firmware includes a number of interface changes that
require driver updates to match.

* Starting from Gen11, the ID to be provided to GuC needs to contain
the engine class in bits [0..2] and the instance in bits [3..6].

NOTE: this patch breaks pointer dereferences in some existing GuC
functions that use the guc_id to dereference arrays but these functions
are not used for now as we have GuC submission disabled and we will
update these functions in follow up patch which requires new IDs.

* The new GuC requires the additional data structure (ADS) and associated
'private_data' pointer to be setup. This is basically a scratch area
of memory that the GuC owns. The size is read from the CSS header.

* There is now a physical to logical engine mapping table in the ADS
which needs to be configured in order for the firmware to load. For
now, the table is initialised with a 1 to 1 mapping.

* GUC_CTL_CTXINFO has been removed from the initialization params.

* reg_state_buffer is maintained internally by the GuC as part of
the private data.

* The ADS layout has changed significantly. This patch updates the
shared structure and also adds better documentation of the layout.

* While i915 does not use GuC doorbells, the firmware now requires
that some initialisation is done.

* The number of engine classes and instances supported in the ADS has
been increased.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201028145826.2949180-2-John.C.Harrison@Intel.com

drm/i915/guc: kill the GuC client

We now only use 1 client without any plan to add more. The client is
also only holding information about the WQ and the process desc, so we
can just move those in the intel_guc structure and always use stage_id
0.

v2: fix comment (John)
v3: fix the comment for real, fix kerneldoc

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191205220243.27403-4-daniele.ceraolospurio@intel.com

drm/i915/guc: kill doorbell code and selftests

Instead of relying on the workqueue, the upcoming reworked GuC
submission flow will offer the host driver indipendent control over
the execution status of each context submitted to GuC. As part of this,
the doorbell usage model has been reworked, with each doorbell being
paired to a single lrc and a doorbell ring representing new work
available for that specific context. This mechanism, however, limits
the number of contexts that can be registered with GuC to the number of
doorbells, which is an undesired limitation. To avoid this limitation,
we requested the GuC team to also provide a H2G that will allow the host
to notify the GuC of work available for a specified lrc, so we can use
that mechanism instead of relying on the doorbells. We can therefore drop
the doorbell code we currently have, also given the fact that in the
unlikely case we'd want to switch back to using doorbells we'd have to
heavily rework it.
The workqueue will still have a use in the new interface to pass special
commands, so that code has been retained for now.

With the doorbells gone and the GuC client becoming even simpler, the
existing GuC selftests don't give us any meaningful coverage so we can
remove them as well. Some selftests might come with the new code, but
they will look different from what we have now so if doesn't seem worth
it to keep the file around in the meantime.

v2: fix comments and commit message (John)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191205220243.27403-3-daniele.ceraolospurio@intel.com

drm/i915/guc: Update H2G enable logging action definition

GuC enable logging H2G action definition changed some time ago from 0xE000
to 0x40. All current GuC FW blobs use this definition, so fix the action
definition in driver to match.

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Robert M. Fosha <robert.m.fosha@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191022163754.23870-2-robert.m.fosha@intel.com

drm/i915/uc: Update copyright and license

Include 2019 in copyright years and start using SPDX tag.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190812092935.21048-1-michal.wajdeczko@intel.com

drm/i915/uc: Move uc firmware layout definitions to dedicated file

Generic uc firmware layout definitions are unlikely to change and
are separate to other GuC specific definitions.

v2: reordered

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190725141308.24660-3-michal.wajdeczko@intel.com

drm/i915/uc: Update drawing for firmware layout

Sphinx was rendering firmware layout as html table, but since
we want to add sizes relations switch to plain text graphics.

v2: also update text and do it before move (Daniele)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190725141308.24660-2-michal.wajdeczko@intel.com

drm/i915/uc: move GuC and HuC files under gt/uc/

Both microcontrollers are part of the GT HW and are closely related to
GT operations. To keep all the files cleanly together, they've been
placed in their own subdir inside the gt/ folder

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713100016.8026-6-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>