drm/i915: Use internal class when counting engine resets

Commit 503579448db9 ("drm/i915/gsc: Mark internal GSC engine with reserved uabi class")
made the GSC0 engine not have a valid uabi class and so broke the engine
reset counting, which in turn was made class based in cb823ed9915b ("drm/i915/gt: Use intel_gt as the primary object for handling resets").

Despite the title and commit text of the latter is not mentioning it (and
has left the storage array incorrectly sized), tracking by class, despite
it adding aliasing in hypthotetical multi-tile systems, is handy for
virtual engines which for instance do not have a valid engine->id.

Therefore we keep that but just change it to use the internal class which
is always valid. We also add a helper to increment the count, which
aligns with the existing getter.

What was broken without this fix were out of bounds reads every time a
reset would happen on the GSC0 engine, or during selftests when storing
and cross-checking the counts in igt_live_test_begin and
igt_live_test_end.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: dfed6b58d54f ("drm/i915/gsc: Mark internal GSC engine with reserved uabi class")
[tursulin: fixed Fixes tag]
Reported-by: Alan Previn Teres Alexis <alan.previn.teres.alexis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231201122109.729006-2-tvrtko.ursulin@linux.intel.com

drm/i915: move gpu error sysfs to i915_gpu_error.c

Hide gpu error specifics in i915_gpu_error.c. This is also cleaner wrt
conditional compilation, as i915_gpu_error.c is only built with
DRM_I915_CAPTURE_ERROR=y.

With this, we can also make i915_first_error_state() static.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231031124502.1772160-3-jani.nikula@intel.com

drm/i915: move gpu error debugfs to i915_gpu_error.c

Hide gpu error specifics in i915_gpu_error.c. This is also cleaner wrt
conditional compilation, as i915_gpu_error.c is only built with
DRM_I915_CAPTURE_ERROR=y.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231031124502.1772160-2-jani.nikula@intel.com

drm/i915: make some error capture functions static

Not needed outside of i915_gpu_error.c.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231031124502.1772160-1-jani.nikula@intel.com

drm/i915/display: Dump also display parameters

GPU error dump contained all module parameters. If we are moving
display parameters to intel_display_params.[ch] they are not dumped
into GPU error dump. This patch is adding moved display parameters
back to GPU error dump. Display parameters are also included in
i915_capabilities

v2: Add parameters to i915_capabilities as well

Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231024124109.384973-3-jouni.hogander@intel.com

drm/i915: Use internal class when counting engine resets

Commit 503579448db9 ("drm/i915/gsc: Mark internal GSC engine with reserved uabi class")
made the GSC0 engine not have a valid uabi class and so broke the engine
reset counting, which in turn was made class based in cb823ed9915b ("drm/i915/gt: Use intel_gt as the primary object for handling resets").

Despite the title and commit text of the latter is not mentioning it (and
has left the storage array incorrectly sized), tracking by class, despite
it adding aliasing in hypthotetical multi-tile systems, is handy for
virtual engines which for instance do not have a valid engine->id.

Therefore we keep that but just change it to use the internal class which
is always valid. We also add a helper to increment the count, which
aligns with the existing getter.

What was broken without this fix were out of bounds reads every time a
reset would happen on the GSC0 engine, or during selftests when storing
and cross-checking the counts in igt_live_test_begin and
igt_live_test_end.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 503579448db9 ("drm/i915/gsc: Mark internal GSC engine with reserved uabi class")
[tursulin: fixed Fixes tag]
Reported-by: Alan Previn Teres Alexis <alan.previn.teres.alexis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231201122109.729006-2-tvrtko.ursulin@linux.intel.com
(cherry picked from commit cf9cb028ac56696ff879af1154c4b2f0b12701fd)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915: separate display info printing from the rest

Add new function intel_display_device_info_print() and print the display
device info there instead of intel_device_info_print(). This also fixes
the display runtime info printing to use the actual runtime info instead
of the static defaults.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/30d4f93c58839bc9312b43423cd43bc0ef655a35.1687878757.git.jani.nikula@intel.com

drm/i915: Dump error capture to kernel log

This is useful for getting debug information out in certain
situations, such as failing kernel selftests and CI runs that don't
log error captures. It is especially useful for things like retrieving
GuC logs as GuC operation can't be tracked by adding printk or ftrace
entries.

v2: Add CONFIG_DRM_I915_DEBUG_GEM wrapper (review feedback by Rodrigo).

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230418181744.3251240-2-John.C.Harrison@Intel.com

drm/i915: Include timeline seqno in error capture

The seqno value actually written out to memory is no longer in the
regular HWSP. Instead, it is now in its own private timeline buffer.
Thus, it is no longer visible in an error capture. So, explicitly read
the value and include that in the capture.

v2: %d -> %u (Alan)

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/20230311063714.570389-4-John.C.Harrison@Intel.com

drm/i915/guc: Rename GuC register state capture node to be more obvious

The GuC specific register state entry in the error capture object was
just called 'capture'. Although the companion 'node' entry was called
'guc_capture_node'. Rename the base entry to be 'guc_capture' instead
so that it is a) more consistent and b) more obvious what it is.

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/20230127002842.3169194-9-John.C.Harrison@Intel.com

drm/i915/guc: Record CTB info in error logs

When debugging GuC communication issues, it is useful to have the CTB
info available. So add the state and buffer contents to the error
capture log.

Also, add a sub-structure for the GuC specific error capture info as
it is now becoming numerous.

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/20220728022028.2190627-5-John.C.Harrison@Intel.com

drm/i915/guc: Add GuC <-> kernel time stamp translation information

It is useful to be able to match GuC events to kernel events when
looking at the GuC log. That requires being able to convert GuC
timestamps to kernel time. So, when dumping error captures and/or GuC
logs, include a stamp in both time zones plus the clock frequency.

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/20220728022028.2190627-4-John.C.Harrison@Intel.com

drm/i915: Add extra registers to GPU error dump

Our internal teams have identified a few additional engine registers
that are worth inspecting in error state dumps during development &
debug. Let's capture and print them as part of our error dump.

For simplicity we'll just dump these registers on gen11 and beyond.
Most of these registers have existed since earlier platforms (e.g., gen6
or gen7) but were initially introduced only for a subset of the
platforms' engines; gen11 seems to be where they became available on all
engines.

Signed-off-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601210646.615946-1-matthew.d.roper@intel.com

drm/i915: Track context current active time

Track context active (on hardware) status together with the start
timestamp.

This will be used to provide better granularity of context
runtime reporting in conjunction with already tracked pphwsp accumulated
runtime.

The latter is only updated on context save so does not give us visibility
to any currently executing work.

As part of the patch the existing runtime tracking data is moved under the
new ce->stats member and updated under the seqlock. This provides the
ability to atomically read out accumulated plus active runtime.

v2:
* Rename and make __intel_context_get_active_time unlocked.

v3:
* Use GRAPHICS_VER.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com> # v1
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401142205.3123159-6-tvrtko.ursulin@linux.intel.com

drm/i915/dmc: abstract GPU error state dump

Only intel_dmc.c should be accessing dmc details directly.

Need to add an i915_error_printf() stub for
CONFIG_DRM_I915_CAPTURE_ERROR=n.

v2: Add the stub (kernel test robot <lkp@intel.com>)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> # v1
Link: https://patchwork.freedesktop.org/patch/msgid/20220330113417.220964-1-jani.nikula@intel.com

drm/i915/guc: Print the GuC error capture output register list.

Print the GuC captured error state register list (string names
and values) when gpu_coredump_state printout is invoked via
the i915 debugfs for flushing the gpu error-state that was
captured prior.

Since GuC could have reported multiple engine register dumps
in a single notification event, parse the captured data
(appearing as a stream of structures) to identify each dump as
a different 'engine-capture-group-output'.

Finally, for each 'engine-capture-group-output' that is found,
verify if the engine register dump corresponds to the
engine_coredump content that was previously populated by the
i915_gpu_coredump function. That function would have copied
the context's vma's including the bacth buffer during the
G2H-context-reset notification that occurred earlier. Perform
this verification check by comparing guc_id, lrca and engine-
instance obtained from the 'engine-capture-group-output' vs a
copy of that same info taken during i915_gpu_coredump. If
they match, then print those vma's as well (such as the batch
buffers).

NOTE: the output format was verified using the gem_exec_capture
IGT test.

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/20220321164527.2500062-14-alan.previn.teres.alexis@intel.com

drm/i915/guc: Plumb GuC-capture into gpu_coredump

Add a flags parameter through all of the coredump creation
functions. Add a bitmask flag to indicate if the top
level gpu_coredump event is triggered in response to
a GuC context reset notification.

Using that flag, ensure all coredump functions that
read or print mmio-register values related to work submission
or command-streamer engines are skipped and replaced with
a calls guc-capture module equivalent functions to retrieve
or print the register dump.

While here, split out display related register reading
and printing into its own function that is called agnostic
to whether GuC had triggered the reset.

For now, introduce an empty printing function that can
filled in on a subsequent patch just to handle formatting.

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/20220321164527.2500062-13-alan.previn.teres.alexis@intel.com

drm/i915/gt: Remove GEN12_SFC_DONE_MAX from register defs header

We shouldn't really be keeping track of how many SFC_DONE registers
our platforms can have, but rather how many SFC hardware units there can
be (each SFC unit will have one corresponding SFC_DONE register). So
drop the stray GEN12_SFC_DONE_MAX definition we had in the register
definition file and replace it with an I915_MAX_SFC that follows the
pattern we use for other hardware units. Note that our hardware has a
2:1:1 ratio of VD:VE:SFC, and as far as we know that pattern should
carry forward to future platforms, so we'll define it as #VCS/2.

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311062835.163744-1-matthew.d.roper@intel.com

drm/i915: move i915_reset_count()/i915_reset_engine_count() out of i915_drv.h

It doesn't help much, as i915_drv.h includes i915_gpu_error.h, but it's
a step in the right direction.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7af2f698a320c1efb0563f56a432c6d122d40b94.1644507885.git.jani.nikula@intel.com

drm/i915: Avoid allocating a page array for the gpu coredump

The gpu coredump typically takes place in a dma_fence signalling
critical path, and hence can't use GFP_KERNEL allocations, as that
means we might hit deadlocks under memory pressure. However
changing to __GFP_KSWAPD_RECLAIM which will be done in an upcoming
patch will instead mean a lower chance of the allocation succeeding.
In particular large contigous allocations like the coredump page
vector.
Remove the page vector in favor of a linked list of single pages.
Use the page lru list head as the list link, as the page owner is
allowed to do that.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211108174547.979714-2-thomas.hellstrom@linux.intel.com

gpu: drm: replace occurrences of invalid character

There are some places at drm that ended receiving a
REPLACEMENT CHARACTER U+fffd ('�'), probably because of
some bad charset conversion.

Fix them by using what it seems to be the proper
character.

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e606930c73029f16673849c57acac061dd923866.1621412009.git.mchehab+huawei@kernel.org

drm/i915: Nuke display error state

I doubt anyone has used the display error state since CS flips
went the way of the dodo. Just nuke it.

It might be semi interesting to have something like this for
FIFO underruns and the like, but as it stands this wouldn't
provide a sufficient amount of information. So would need
an extensive rewrite anyway.

The lockless power well handling is also racy, so this could
just be contributing noise to test results if we end up
accessing something with the relevant power well already
disabled.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210505191140.14215-1-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>

drm/i915: Improve record of hung engines in error state

Between events which trigger engine and GPU resets and capturing the error
state we lose information on which engine triggered the reset. Improve
this by passing in the hung engine mask down to error capture.

Result is that the list of engines in user visible "GPU HANG: ecode
<gen>:<engines>:<ecode>, <process>" is now a list of hanging and not just
active engines. Most importantly the displayed process is now the one
which was actually hung.

v2:
* Stub prototype. (Chris)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201104134743.916027-1-tvrtko.ursulin@linux.intel.com

drm/i915: Move the engine mask to intel_gt_info

Since the engines belong to the GT, move the runtime-updated list of
available engines to the intel_gt struct. The original mask has been
renamed to indicate it contains the maximum engine list that can be
found on a matching device.

In preparation for other info being moved to the gt in follow up patches
(sseu), introduce an intel_gt_info structure to group all gt-related
runtime info.

v2: s/max_engine_mask/platform_engine_mask (tvrtko), fix selftest

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Cc: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> #v1
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200708003952.21831-5-daniele.ceraolospurio@intel.com

drm/i915: Replace zero-length array with flexible-array

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
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/20200507185408.GA14561@embeddedor

drm/i915: Drop rq->ring->vma peeking from error capture

We only hold the active spinlock while dumping the error state, and this
does not prevent another thread from retiring the request -- as it is
quite possible that despite us capturing the current state, the GPU has
completed the request. As such, it is dangerous to dereference state
below the request as it may already be freed, and the simplest way to
avoid the danger is not include it in the error state.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1788
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200424191410.27570-1-chris@chris-wilson.co.uk

drm/i915: Track hw reported context runtime

GPU saves accumulated context runtime (in CS timestamp units) in PPHWSP
which will be useful for us in cases when we are not able to track context
busyness ourselves (like with GuC). Keep a copy of this in struct
intel_context from where it can be easily read even if the context is not
pinned.

v2:
(Chris)
* Do not store pphwsp address in intel_context.
* Log CS wrap-around.
* Simplify calculation by relying on integer wraparound.
v3:
* Include total/avg in traces and error state for debugging

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200216133620.394962-1-chris@chris-wilson.co.uk

drm/i915: Stub out i915_gpu_coredump_put

i915_gpu_coreddump_put is currently only defined if
CONFIG_DRM_I915_CAPTURE_ERROR is enabled, provide a stub otherwise.

Reported-by: Mike Lothian <mike@fireburn.co.uk>
Fixes: 742379c0c400 ("drm/i915: Start chopping up the GPU error capture")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mike Lothian <mike@fireburn.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200124192255.541355-1-chris@chris-wilson.co.uk
(cherry picked from commit 7e36505d0cf82f2920f2fd22ebb14a8b540396a3)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915: Fix i915_error_state_store error defination

Since commit 742379c0c4001 ("drm/i915: Start chopping up the GPU error
capture"), function 'i915_error_state_store' was defined and used with
only one parameter.

But if no 'CONFIG_DRM_I915_CAPTURE_ERROR', this function was defined
with two parameter.

This may lead compile error. This patch fix it.

Fixes: 742379c0c400 ("drm/i915: Start chopping up the GPU error capture")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200117073436.6507-1-zhangxiaoxu5@huawei.com
(cherry picked from commit 04062c58faafddf62006c6f8e5077dc050e8207e)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/i915/gt: Hook up CS_MASTER_ERROR_INTERRUPT

Now that we have offline error capture and can reset an engine from
inside an atomic context while also preserving the GPU state for
post-mortem analysis, it is time to handle error interrupts thrown by
the command parser.

This provides a much, much faster mechanism for us to detect known
problems than using heartbeats/hangchecks, and also provides a mechanism
for when those are disabled. However, it is limited to problems the HW
can detect in the CS and so not a complete solution for detecting lockups.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128204318.4182039-2-chris@chris-wilson.co.uk

drm/i915: Stub out i915_gpu_coredump_put

i915_gpu_coreddump_put is currently only defined if
CONFIG_DRM_I915_CAPTURE_ERROR is enabled, provide a stub otherwise.

Reported-by: Mike Lothian <mike@fireburn.co.uk>
Fixes: 742379c0c400 ("drm/i915: Start chopping up the GPU error capture")
Fixes: 748317386afb ("drm/i915/execlists: Offline error capture")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mike Lothian <mike@fireburn.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200124192255.541355-1-chris@chris-wilson.co.uk

drm/i915: Fix i915_error_state_store error defination

Since commit 742379c0c4001 ("drm/i915: Start chopping up the GPU error
capture"), function 'i915_error_state_store' was defined and used with
only one parameter.

But if no 'CONFIG_DRM_I915_CAPTURE_ERROR', this function was defined
with two parameter.

This may lead compile error. This patch fix it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200117073436.6507-1-zhangxiaoxu5@huawei.com

drm/i915: Fix too few arguments to function i915_capture_error_state

If 'CONFIG_DRM_I915_CAPTURE_ERROR' not configured, there is an error
when compile the kernel:

drivers/gpu/drm/i915/gt/intel_reset.c:
In function intel_gt_handle_error:
drivers/gpu/drm/i915/gt/intel_reset.c:1233:3:
error: too few arguments to function i915_capture_error_state
i915_capture_error_state(gt->i915);
^~~~~~~~~~~~~~~~~~~~~~~~
In file included
from ./drivers/gpu/drm/i915/i915_drv.h:97:0,
from ./drivers/gpu/drm/i915/display/intel_display_types.h:46,
from drivers/gpu/drm/i915/gt/intel_reset.c:10:
./drivers/gpu/drm/i915/i915_gpu_error.h:267:20: note: declared here
static inline void i915_capture_error_state(struct drm_i915_private *dev_priv,

Fixes: 742379c0c400 ("drm/i915: Start chopping up the GPU error capture")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200113081942.15982-1-zhangxiaoxu5@huawei.com

drm/i915: Fix multiple definition of 'i915_vma_capture_finish'

If 'CONFIG_DRM_I915_CAPTURE_ERROR' not configured, there are some
errors like:

drivers/gpu/drm/i915/i915_irq.o:
In function `i915_vma_capture_finish':
./drivers/gpu/drm/i915/i915_gpu_error.h:312:
multiple definition of `i915_vma_capture_finish'
drivers/gpu/drm/i915/i915_drv.o:
./drivers/gpu/drm/i915/i915_gpu_error.h:312: first defined here

So, add 'static inline' on the defineation of the 'i915_vma_capture_finish'

Fixes: d713e3ab93fdc("drm/i915: Correct typo in i915_vma_compress_finish stub")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200113104009.13274-1-zhangxiaoxu5@huawei.com

drm/i915: Correct typo in i915_vma_compress_finish stub

A copy and paste error in setting up the !CONFIG_DRM_I915_CAPTURE_ERROR
stubs left a conflicting duplicate declaration.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200111083007.1619228-1-chris@chris-wilson.co.uk

drm/i915: Drop request list from error state

The list of requests from after the hang tells little about the hang
itself, only how busy userspace was after the fact. As it pertains
nothing to the HW state, drop it from the error state.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110123059.1348712-4-chris@chris-wilson.co.uk

drm/i915: Drop the shadow ring state from the error capture

The shadow ring regs (ring->head, ring->tail) are meaningless in the
post-mortem dump as they do not related to anything on HW. Remove them
from the coredump.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110123059.1348712-3-chris@chris-wilson.co.uk

drm/i915: Start chopping up the GPU error capture

In the near future, we will want to start a GPU error capture from a new
context, from inside the softirq region of a forced preemption. To do
so requires us to break up the monolithic error capture to provide new
entry points with finer control; in particular focusing on one
engine/gt, and being able to compose an error state from little pieces
of HW capture.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110123059.1348712-1-chris@chris-wilson.co.uk

drm/i915/tgl: Add gam instdone

This has been asked from us already. Prepare for the next
time.

Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191029163841.5224-2-mika.kuoppala@linux.intel.com

drm/i915/tgl: Add SFC instdone to error state

On debugging media workload hangs, sfc instdone
might prove useful in future. Be prepared.

Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191029163841.5224-1-mika.kuoppala@linux.intel.com

drm/i915: capture aux page table error register

TGL introduced a feature in which we map the main surface to the
auxiliary surface. If we screw up the page tables, the HW has a
register to tell us which engine encounters a fault in the page table
walk.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
[ickle: Be brave and apply to gen12]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191025121718.18806-1-lionel.g.landwerlin@intel.com

drm/i915/gt: Replace hangcheck by heartbeats

Replace sampling the engine state every so often with a periodic
heartbeat request to measure the health of an engine. This is coupled
with the forced-preemption to allow long running requests to survive so
long as they do not block other users.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: Jon Bloomfield <jon.bloomfield@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191023133108.21401-5-chris@chris-wilson.co.uk

drm/i915: Remove logical HW ID

With the introduction of ctx->engines[] we allow multiple logical
contexts to be used on the same engine (e.g. with virtual engines).
According to bspec, aach logical context requires a unique tag in order
for context-switching to occur correctly between them. [Simple
experiments show that it is not so easy to trick the HW into performing
a lite-restore with matching logical IDs, though my memory from early
Broadwell experiments do suggest that it should be generating
lite-restores.]

We only need to keep a unique tag for the active lifetime of the
context, and for as long as we need to identify that context. The HW
uses the tag to determine if it should use a lite-restore (why not the
LRCA?) and passes the tag back for various status identifies. The only
status we need to track is for OA, so when using perf, we assign the
specific context a unique tag.

v2: Calculate required number of tags to fill ELSP.

Fixes: 976b55f0e1db ("drm/i915: Allow a context to define its set of engines")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111895
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-14-chris@chris-wilson.co.uk

drm/i915: include GTT page-size info in error state

It might prove useful in the future to know if the vma is utilising
huge-GTT-pages. Related to this is the GTT cache, where there is some HW
"quirkiness" where it must be disabled if using 2M pages, so include
that for good measure.

Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Matthew Auld <matthew.auld@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/20190909171646.22090-1-matthew.auld@intel.com

drm/i915: Only include active engines in the capture state

Skip printing out idle engines that did not contribute to the GPU hang.
As the number of engines gets ever larger, we have increasing noise in
the error state where typically there is only one guilty request on one
engine that we need to inspect.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808144511.32269-1-chris@chris-wilson.co.uk

drm/i915: Rely on spinlock protection for GPU error capture

Trust that we now have adequate protection over the low level structures
via the engine->active.lock to allow ourselves to capture the GPU error
state without the heavy hammer of stop_machine(). Sadly this does mean
that we have to forgo some of the lesser used information (not derived
from the active state) that is not controlled by the active locks. This
includes the list of buffers in the ppGTT and pinned globally in the
GGTT. Originally this was used to manually verify relocations, but
hasn't been required for sometime and modern mesa now has the habit of
ensuring that all interesting buffers within a batch are captured in their
entirety (that are the auxiliary state buffers, but not the textures).

A useful side-effect is that this allows us to restore error capturing
for Braswell and Broxton.

v2: Use pagevec for a typical arbitrary number of preallocated pages

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/20190722222847.24178-1-chris@chris-wilson.co.uk

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>

drm/i915/gt: Use intel_gt as the primary object for handling resets

Having taken the first step in encapsulating the functionality by moving
the related files under gt/, the next step is to start encapsulating by
passing around the relevant structs rather than the global
drm_i915_private. In this step, we pass intel_gt to intel_reset.c

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712192953.9187-1-chris@chris-wilson.co.uk

drm/i915: Invert the GEM wakeref hierarchy

In the current scheme, on submitting a request we take a single global
GEM wakeref, which trickles down to wake up all GT power domains. This
is undesirable as we would like to be able to localise our power
management to the available power domains and to remove the global GEM
operations from the heart of the driver. (The intent there is to push
global GEM decisions to the boundary as used by the GEM user interface.)

Now during request construction, each request is responsible via its
logical context to acquire a wakeref on each power domain it intends to
utilize. Currently, each request takes a wakeref on the engine(s) and
the engines themselves take a chipset wakeref. This gives us a
transition on each engine which we can extend if we want to insert more
powermangement control (such as soft rc6). The global GEM operations
that currently require a struct_mutex are reduced to listening to pm
events from the chipset GT wakeref. As we reduce the struct_mutex
requirement, these listeners should evaporate.

Perhaps the biggest immediate change is that this removes the
struct_mutex requirement around GT power management, allowing us greater
flexibility in request construction. Another important knock-on effect,
is that by tracking engine usage, we can insert a switch back to the
kernel context on that engine immediately, avoiding any extra delay or
inserting global synchronisation barriers. This makes tracking when an
engine and its associated contexts are idle much easier -- important for
when we forgo our assumed execution ordering and need idle barriers to
unpin used contexts. In the process, it means we remove a large chunk of
code whose only purpose was to switch back to the kernel context.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190424200717.1686-5-chris@chris-wilson.co.uk

drm/i915: Move GraphicsTechnology files under gt/

Start partitioning off the code that talks to the hardware (GT) from the
uapi layers and move the device facing code under gt/

One casualty is s/intel_ringbuffer.h/intel_engine.h/ with the plan to
subdivide that header and body further (and split out the submission
code from the ringbuffer and logical context handling). This patch aims
to be simple motion so git can fixup inflight patches with little mess.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190424174839.7141-1-chris@chris-wilson.co.uk

drm/i915: Move intel_engine_mask_t around for use by i915_request_types.h

We want to use intel_engine_mask_t inside i915_request.h, which means
extracting it from the general header file mess and placing it inside a
types.h. A knock on effect is that the compiler wants to warn about
type-contraction of ALL_ENGINES into intel_engine_maskt_t, so prepare
for the worst.

v2: Use intel_engine_mask_t consistently
v3: Move I915_NUM_ENGINES to its natural home at the end of the enum

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>
Cc: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190401162641.10963-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drm/i915: Stop storing ctx->user_handle

The user_handle need only be known by userspace for it to lookup the
context via the idr; internally we have no use for it.

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/20190321140711.11190-3-chris@chris-wilson.co.uk

drm/i915: Stop capturing semaphore registers for gen6/7 GPU hangs

We no longer use the semaphore sync registers on gen6/7, so including
them in the GPU error state is mere noise.

References: 6faf5916e6be ("drm/i915: Remove HW semaphores for gen7 inter-engine synchronisation")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190305150914.11340-2-chris@chris-wilson.co.uk

drm/i915: Remove i915_request.global_seqno

Having weaned the interrupt handling off using a single global execution
queue, we no longer need to emit a global_seqno. Note that we still have
a few assumptions about execution order along engine timelines, but this
removes the most obvious artefact!

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/20190226094922.31617-3-chris@chris-wilson.co.uk

drm/i915: Remove access to global seqno in the HWSP

Stop accessing the HWSP to read the global seqno, and stop tracking the
mirror in the engine's execution timeline -- it is unused.

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/20190226094922.31617-2-chris@chris-wilson.co.uk

drm/i915: Use time based guilty context banning

Currently, we accumulate each time a context hangs the GPU, offset
against the number of requests it submits, and if that score exceeds a
certain threshold, we ban that context from submitting any more requests
(cancelling any work in flight). In contrast, we use a simple timer on
the file, that if we see more than a 9 hangs faster than 60s apart in
total across all of its contexts, we will ban the client from creating
any more contexts. This leads to a confusing situation where the file
may be banned before the context, so lets use a simple timer scheme for
each.

If the context submits 3 hanging requests within a 120s period, declare
it forbidden to ever send more requests.

This has the advantage of not being easy to repair by simply sending
empty requests, but has the disadvantage that if the context is idle
then it is forgiven. However, if the context is idle, it is not
disrupting the system, but a hog can evade the request counting and
cause much more severe disruption to the system.

Updating ban_score from request retirement is dubious as the retirement
is purposely not in sync with request submission (i.e. we try and batch
retirement to reduce overhead and avoid latency on submission), which
leads to surprising situations where we can forgive a hang immediately
due to a backlog of requests from before the hang being retired
afterwards.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190219122215.8941-2-chris@chris-wilson.co.uk

drm/i915: Revoke mmaps and prevent access to fence registers across reset

Previously, we were able to rely on the recursive properties of
struct_mutex to allow us to serialise revoking mmaps and reacquiring the
FENCE registers with them being clobbered over a global device reset.
I then proceeded to throw out the baby with the bath water in order to
pursue a struct_mutex-less reset.

Perusing LWN for alternative strategies, the dilemma on how to serialise
access to a global resource on one side was answered by
https://lwn.net/Articles/202847/ -- Sleepable RCU:

1 int readside(void) {
2 int idx;
3 rcu_read_lock();
4 if (nomoresrcu) {
5 rcu_read_unlock();
6 return -EINVAL;
7 }
8 idx = srcu_read_lock(&ss);
9 rcu_read_unlock();
10 /* SRCU read-side critical section. */
11 srcu_read_unlock(&ss, idx);
12 return 0;
13 }
14
15 void cleanup(void)
16 {
17 nomoresrcu = 1;
18 synchronize_rcu();
19 synchronize_srcu(&ss);
20 cleanup_srcu_struct(&ss);
21 }

No more worrying about stop_machine, just an uber-complex mutex,
optimised for reads, with the overhead pushed to the rare reset path.

However, we do run the risk of a deadlock as we allocate underneath the
SRCU read lock, and the allocation may require a GPU reset, causing a
dependency cycle via the in-flight requests. We resolve that by declaring
the driver wedged and cancelling all in-flight rendering.

v2: Use expedited rcu barriers to match our earlier timing
characteristics.
v3: Try to annotate locking contexts for sparse
v4: Reduce selftest lock duration to avoid a reset deadlock with fences
v5: s/srcu/reset_backoff_srcu/
v6: Remove more stale comments

Testcase: igt/gem_mmap_gtt/hang
Fixes: eb8d0f5af4ec ("drm/i915: Remove GPU reset dependence on struct_mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190208153708.20023-2-chris@chris-wilson.co.uk

drm/i915: Drop fake breadcrumb irq

Missed breadcrumb detection is defunct due to the tight coupling with
dma_fence signaling and the myriad ways we may signal fences from
everywhere but from an interrupt, i.e. we frequently signal a fence
before we even see its interrupt. This means that even if we miss an
interrupt for a fence, it still is signaled before our breadcrumb
hangcheck fires, so simplify the breadcrumb hangchecking by moving it
into the GPU hangcheck and forgo fake interrupts.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129205230.19056-3-chris@chris-wilson.co.uk

drm/i915: Replace global breadcrumbs with per-context interrupt tracking

A few years ago, see commit 688e6c725816 ("drm/i915: Slaughter the
thundering i915_wait_request herd"), the issue of handling multiple
clients waiting in parallel was brought to our attention. The
requirement was that every client should be woken immediately upon its
request being signaled, without incurring any cpu overhead.

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

Before commit 688e6c725816, the solution was simple. Every client
waiting on a request would be woken on every interrupt and each would do
a heavyweight check to see if their request was complete. Commit
688e6c725816 introduced an rbtree so that only the earliest waiter on
the global timeline would woken, and would wake the next and so on.
(Along with various complications to handle requests being reordered
along the global timeline, and also a requirement for kthread to provide
a delegate for fence signaling that had no process context.)

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

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

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

References: 688e6c725816 ("drm/i915: Slaughter the thundering i915_wait_request herd")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129205230.19056-2-chris@chris-wilson.co.uk

drm/i915: Remove GPU reset dependence on struct_mutex

Now that the submission backends are controlled via their own spinlocks,
with a wave of a magic wand we can lift the struct_mutex requirement
around GPU reset. That is we allow the submission frontend (userspace)
to keep on submitting while we process the GPU reset as we can suspend
the backend independently.

The major change is around the backoff/handoff strategy for performing
the reset. With no mutex deadlock, we no longer have to coordinate with
any waiter, and just perform the reset immediately.

Testcase: igt/gem_mmap_gtt/hang # regresses
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125132230.22221-3-chris@chris-wilson.co.uk

drm/i915: Serialise concurrent calls to i915_gem_set_wedged()

Make i915_gem_set_wedged() and i915_gem_unset_wedged() behaviour more
consistent if called concurrently, and only do the wedging and reporting
once, curtailing any possible race where we start unwedging in the middle
of a wedge.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114210408.4561-2-chris@chris-wilson.co.uk

drm/i915: start moving runtime device info to a separate struct

First move the low hanging fruit, the fields that are only initialized
runtime. Use RUNTIME_INFO() exclusively to access the fields.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/c24fe7a4b0492a888690c46814c0ff21ce2f12b1.1546267488.git.jani.nikula@intel.com

drm/i915: Cache the error string

Currently, we convert the error state into a string every time we read
from sysfs (and sysfs reads in page size (4KiB) chunks). We do try to
window the string and only capture the portion that is being read, but
that means that we must always convert up to the window to find the
start. For a very large error state bordering on EXEC_OBJECT_CAPTURE
abuse, this is noticeable as it degrades to O(N^2)!

As we do not have a convenient hook for sysfs open(), and we would like
to keep the lazy conversion into a string, do the conversion of the
whole string on the first read and keep the string until the error state
is freed.

v2: Don't double advance simple_read_from_buffer
v3: Due to extreme pain of lack of vrealloc, use a scatterlist
v4: Keep the forward iterator loosely cached
v5: Stylistic improvements to reduce patch size

Reported-by: Jason Ekstrand <jason@jlekstrand.net>
Testcase: igt/gem_exec_capture/many*
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181123132325.26541-1-chris@chris-wilson.co.uk

drm/i915: Prevent machine hang from Broxton's vtd w/a and error capture

Since capturing the error state requires fiddling around with the GGTT
to read arbitrary buffers and is itself run under stop_machine(), it
deadlocks the machine (effectively a hard hang) when run in conjunction
with Broxton's VTd workaround to serialize GGTT access.

v2: Store the ERR_PTR in first_error so that the error can be reported
to the user via sysfs.
v3: Mention the quirk in dmesg (using info as per usual)

Fixes: 0ef34ad6222a ("drm/i915: Serialize GTT/Aperture accesses on BXT")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: John Harrison <john.C.Harrison@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181102161232.17742-5-chris@chris-wilson.co.uk
(cherry picked from commit fb6f0b64e455b207a636346588e65bf9598d30eb)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drm/i915: Prevent machine hang from Broxton's vtd w/a and error capture

Since capturing the error state requires fiddling around with the GGTT
to read arbitrary buffers and is itself run under stop_machine(), it
deadlocks the machine (effectively a hard hang) when run in conjunction
with Broxton's VTd workaround to serialize GGTT access.

v2: Store the ERR_PTR in first_error so that the error can be reported
to the user via sysfs.
v3: Mention the quirk in dmesg (using info as per usual)

Fixes: 0ef34ad6222a ("drm/i915: Serialize GTT/Aperture accesses on BXT")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: John Harrison <john.C.Harrison@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181102161232.17742-5-chris@chris-wilson.co.uk

drm/i915: Handle incomplete Z_FINISH for compressed error states

The final call to zlib_deflate(Z_FINISH) may require more output
space to be allocated and so needs to re-invoked. Failure to do so in
the current code leads to incomplete zlib streams (albeit intact due to
the use of Z_SYNC_FLUSH) resulting in the occasional short object
capture.

v2: Check against overrunning our pre-allocated page array
v3: Drop Z_SYNC_FLUSH entirely

Testcase: igt/i915-error-capture.js
Fixes: 0a97015d45ee ("drm/i915: Compress GPU objects in error state")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003082422.23214-1-chris@chris-wilson.co.uk
(cherry picked from commit 83bc0f5b432f60394466deef16fc753e27371d0b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drm/i915: Handle incomplete Z_FINISH for compressed error states

The final call to zlib_deflate(Z_FINISH) may require more output
space to be allocated and so needs to re-invoked. Failure to do so in
the current code leads to incomplete zlib streams (albeit intact due to
the use of Z_SYNC_FLUSH) resulting in the occasional short object
capture.

v2: Check against overrunning our pre-allocated page array
v3: Drop Z_SYNC_FLUSH entirely

Testcase: igt/i915-error-capture.js
Fixes: 0a97015d45ee ("drm/i915: Compress GPU objects in error state")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003082422.23214-1-chris@chris-wilson.co.uk

drm/i915: Track vma activity per fence.context, not per engine

In the next patch, we will want to be able to use more flexible request
timelines that can hop between engines. From the vma pov, we can then
not rely on the binding of this request to an engine and so can not
ensure that different requests are ordered through a per-engine
timeline, and so we must track activity of all timelines. (We track
activity on the vma itself to prevent unbinding from HW before the HW
has finished accessing it.)

v2: Switch to a rbtree for 32b safety (since using u64 as a radixtree
index is fraught with aliasing of unsigned longs).
v3: s/lookup_active/active_instance/ because we can never agree on names

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706103947.15919-5-chris@chris-wilson.co.uk

drm/i915/icl: Read the correct Gen11 interrupt registers

Stop reading some now deprecated interrupt registers in both
debugfs and error state. Instead, read the new equivalents in the
Gen11 interrupt repartitioning scheme.

Note that the equivalent to the PM ISR & IIR cannot be read without
affecting the current state of the system, so I've opted for leaving
them out. See gen11_reset_one_iir() for more info.

v2: else if !!! (Paulo)
v3: another else if (Vinay)
v4:
- Rebased
- Renamed patch
- Improved the ordering of GENs
- Improved the printing of per-GEN info
v5: Avoid maybe-unitialized & add comment explaining the lack
of PM ISR & IIR

Suggested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
[Paulo: fix commit message and coding style.]
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1525989595-18220-1-git-send-email-oscar.mateo@intel.com

drm/i915: Show ring->start for the ELSP context/request queue

Since the advent of execlists, the HW no longer executes from a single
statically assigned ring, but instead switches to a different ring for
each context (logical ringbuffer contexts as it is called). So a good way
to tally the executing context against what we have queued is by
comparing the RING_START register against our requests. Make it so.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180502104150.29874-1-chris@chris-wilson.co.uk

drm/i915: Print error state times relative to capture

Using plain jiffies in error state output makes the output
time differences relative to the current system time. This
is wrong as it makes output time differences dependent
of when the error state is printed rather than when it is
captured.

Store capture jiffies into error state and use it
when outputting the state to fix time differences output.

v2: use engine timestamp as epoch, output formatting (Chris)
v3: pass epoch to print_engine/request (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180430075259.4476-1-mika.kuoppala@linux.intel.com

drm/i915: Pack params to engine->schedule() into a struct

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

drm/i915: Pass the set of guilty engines to i915_reset()

Currently, we rely on inspecting the hangcheck state from within the
i915_reset() routines to determine which engines were guilty of the
hang. This is problematic for cases where we want to run
i915_handle_error() and call i915_reset() independently of hangcheck.
Instead of relying on the indirect parameter passing, turn it into an
explicit parameter providing the set of stalled engines which then are
treated as guilty until proven innocent.

While we are removing the implicit stalled parameter, also make the
reason into an explicit parameter to i915_reset(). We still need a
back-channel for i915_handle_error() to hand over the task to the locked
waiter, but let's keep that its own channel rather than incriminate
another.

This leaves stalled/seqno as being private to hangcheck, with no more
nefarious snooping by reset, be it whole-device or per-engine. \o/

The only real issue now is that this makes it crystal clear that we
don't actually do any testing of hangcheck per se in
drv_selftest/live_hangcheck, merely of resets!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180406220354.18911-2-chris@chris-wilson.co.uk

drm/i915: Add control flags to i915_handle_error()

Not all callers want the GPU error to handled in the same way, so expose
a control parameter. In the first instance, some callers do not want the
heavyweight error capture so add a bit to request the state to be
captured and saved.

v2: Pass msg down to i915_reset/i915_reset_engine so that we include the
reason for the reset in the dev_notice(), superseding the earlier option
to not print that notice.
v3: Stash the reason inside the i915->gpu_error to handover to the direct
reset from the blocking waiter.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180320100449.1360-2-chris@chris-wilson.co.uk

drm/i915: Move i915_gpu_error into its own header

Error state management code was moved into separate .c unit
but we didn't move related definitions into own header.

v2: move also intel_display_error_state forward decl
fix ("Prefer 'unsigned int' to bare use of 'unsigned'")
warnings detected by checkpatch in moved code (Michal)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@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/20180308095037.18264-5-michal.wajdeczko@intel.com