Introduces a new parameters to execbuf so that we can specify syncobj
handles as well as timeline points.

v2: Reuse i915_user_extension_fn

v3: Check that the chained extension is only present once (Chris)

v4: Check that dma_fence_chain_find_seqno returns a non NULL fence (Lionel)

v5: Use BIT_ULL (Chris)

v6: Fix issue with already signaled timeline points,
    dma_fence_chain_find_seqno() setting fence to NULL (Chris)

v7: Report ENOENT with invalid syncobj handle (Lionel)

v8: Check for out of order timeline point insertion (Chris)

v9: After explanations on
    https://lists.freedesktop.org/archives/dri-devel/2019-August/229287.html
    drop the ordering check from v8 (Lionel)

v10: Set first extension enum item to 1 (Jason)

v11: Rebase

v12: Allow multiple extension nodes of timeline syncobj (Chris)
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Co-authored-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v11)
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804085954.350343-3-lionel.g.landwerlin@intel.com
Link: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2901Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

We're planning to use this for a couple of new feature where we need
to provide additional parameters to execbuf.

v2: Check for invalid flags in execbuffer2 (Lionel)

v3: Rename I915_EXEC_EXT -> I915_EXEC_USE_EXTENSIONS (Chris)

v4: Rebase
    Move array fence parsing in i915_gem_do_execbuffer()
Signed-off-by: NLionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804085954.350343-2-lionel.g.landwerlin@intel.com
Link: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2901Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

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: NDaniele 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: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200708003952.21831-5-daniele.ceraolospurio@intel.com

Rather than reuse the common ctx->mutex for locking the execbuffer LUT,
split it into its own lock to avoid being taken [as part of ctx->mutex]
at inappropriate times. In particular to avoid the inversion from taking
the timeline->mutex for the whole execbuf submission in the next patch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200703004306.11117-1-chris@chris-wilson.co.uk

The obj->lut_list is traversed when the object is closed as the file
table is destroyed during process termination. As this occurs before we
kill any outstanding context if, due to some bug or another, the closure
is blocked, then we fail to shootdown any inflight operations
potentially leaving the GPU spinning forever. As we only need to guard
the list against concurrent closures and insertions, the hold is short
and merits being treated as a simple spinlock.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701084439.17025-1-chris@chris-wilson.co.uk

If the execbuf is interrupted after building the cmdparser pipeline, and
before we commit to submitting the request to HW, we would attempt to
clean up the cmdparser early. While we held active references to the vma
being parsed and constructed, we did not hold an active reference for
the buffer pool itself. The result was that an interrupted execbuf could
still have run the cmdparser pipeline, but since the buffer pool was
idle, its target vma could have been recycled.

Note this problem only occurs if the cmdparser is running async due to
pipelined waits on busy fences, and the execbuf is interrupted.

Fixes: 686c7c35 ("drm/i915/gem: Asynchronous cmdparser")
Fixes: 16e87459 ("drm/i915/gt: Move the batch buffer pool from the engine to the gt")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200604103751.18816-1-chris@chris-wilson.co.uk
(cherry picked from commit 57a78ca4)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Unused as of commit 9e0f9464 ("drm/i915/gem: Async GPU relocations
only"), but left behind.

>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:933:21: error: unused function 'unmask_page' [-Werror,-Wunused-function]
static inline void *unmask_page(unsigned long p)
^
>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:938:28: error: unused function 'unmask_flags' [-Werror,-Wunused-function]
static inline unsigned int unmask_flags(unsigned long p)
^
>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:945:33: error: unused function 'cache_to_ggtt' [-Werror,-Wunused-function]
static inline struct i915_ggtt *cache_to_ggtt(struct reloc_cache *cache)
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200605200357.13069-1-chris@chris-wilson.co.uk

Reduce the 3 relocation paths down to the single path that accommodates
all. The primary motivation for this is to guard the relocations with a
natural fence (derived from the i915_request used to write the
relocation from the GPU).

The tradeoff in using async gpu relocations is that it increases latency
over using direct CPU relocations, for the cases where the target is
idle and accessible by the CPU. The benefit is greatly reduced lock
contention and improved concurrency by pipelining.

Note that forcing the async gpu relocations does reveal a few issues
they have. Firstly, is that they are visible as writes to gem_busy,
causing to mark some buffers are being to written to by the GPU even
though userspace only reads. Secondly is that, in combination with the
cmdparser, they can cause priority inversions. This should be the case
where the work is being put into a common workqueue losing our priority
information and so being executed in FIFO from the worker, denying us
the opportunity to reorder the requests afterwards.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200604211457.19696-1-chris@chris-wilson.co.uk

If the execbuf is interrupted after building the cmdparser pipeline, and
before we commit to submitting the request to HW, we would attempt to
clean up the cmdparser early. While we held active references to the vma
being parsed and constructed, we did not hold an active reference for
the buffer pool itself. The result was that an interrupted execbuf could
still have run the cmdparser pipeline, but since the buffer pool was
idle, its target vma could have been recycled.

Note this problem only occurs if the cmdparser is running async due to
pipelined waits on busy fences, and the execbuf is interrupted.

Fixes: 686c7c35 ("drm/i915/gem: Asynchronous cmdparser")
Fixes: 16e87459 ("drm/i915/gt: Move the batch buffer pool from the engine to the gt")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200604103751.18816-1-chris@chris-wilson.co.uk

We infrequently use the direct i915 backpointer from the i915_request,
so do we really need to waste the space in the struct for it? 8 bytes
from the most frequently allocated struct vs an 3 bytes and pointer
chasing in using rq->engine->i915?
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAkeem G Abodunrin <akeem.g.abodunrin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200602220953.21178-1-chris@chris-wilson.co.uk

Leave the error propagation in place, but limit the warnings to only
show up in CI if the unlikely errors are hit.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200525141957.3061-2-chris@chris-wilson.co.uk

struct drm_device specific drm_WARN* macros include device information
in the backtrace, so we know what device the warnings originate from.

Prefer drm_WARN* over WARN* at places where struct drm_device pointer
can be extracted.
Signed-off-by: NPankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504181600.18503-6-pankaj.laxminarayan.bharadiya@intel.com

Now that we have fast timeslicing on semaphores, we no longer need to
prioritise none-semaphore work as we will yield any work blocked on a
semaphore to the next in the queue. Previously with no timeslicing,
blocking on the semaphore caused extremely bad scheduling with multiple
clients utilising multiple rings. Now, there is no impact and we can
remove the complication.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200513173504.28322-1-chris@chris-wilson.co.uk

Since there can only be one of in_fence/exec_fence, just use the single
in_fence local.

v2: Consolidate lookup
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200513180937.28992-1-chris@chris-wilson.co.uk

Upon waiting a request (when asked), we gave that request a small
priority boost, not enough for it to cause preemption, but enough for it
to be scheduled next before all equals. We also used that bit to give
new clients a small priority boost, similar to FQ_CODEL, such that we
favoured short interactive tasks ahead of long running streams.

However, this is causing lots of complications with timeslicing where we
both want to honour the boost and yet ignore it. Those complications
cause unexpected user behaviour (tasks not being timesliced and run
concurrently as epxected), and the easiest way to resolve that is to
remove the boost. Hopefully, we can find a compromise again if we need
to, but in theory timeslicing itself and future more advanced schedulers
should give us the interactivity boost we seek.

Testcase: igt/gem_exec_schedule/lateslice
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200507152338.7452-3-chris@chris-wilson.co.uk

The older arches did not convert MI_STORE_DATA_IMM to using the GTT, but
left them writing to a physical address. The notes suggest that the
primary reason would be so that the writes were cache coherent, as the
CPU cache uses physical tagging. As such we did not implement the
legacy variant of MI_STORE_DATA_IMM and so left all the relocations
synchronous -- but with a small function to convert from the vma address
into the physical address, we can implement asynchronous relocs on these
older arches, fixing up a few tests that require them.

In order to be able to test the legacy paths, refactor the gpu
relocations so that we can hook them up to a selftest.

v2: Use an array of offsets not enum labels for the selftest
v3: Refactor the common igt_hexdump()

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/757Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504140629.28240-1-chris@chris-wilson.co.uk

It is required that a chained batch be in the same address domain as its
parent, and also that must be specified in the command for earlier gen
as it is not inferred from the chaining until gen6.

Fixes: 964a9b0f ("drm/i915/gem: Use chained reloc batches")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504125149.4396-1-chris@chris-wilson.co.uk

If at first we don't succeed, try try again.

Not all engines may support the MI ops we need to perform asynchronous
relocation patching, and so we end up falling back to a synchronous
operation that has a liability of blocking. However, Tvrtko pointed out
we don't need to use the same engine to perform the relocations as we
are planning to execute the execbuf on, and so if we switch over to a
working engine, we can perform the relocation asynchronously. The user
execbuf will be queued after the relocations by virtue of fencing.

This patch creates a new context per execbuf requiring asynchronous
relocations on an unusable engines. This is perhaps a bit excessive and
can be ameliorated by a small context cache, but for the moment we only
need it for working around a little used engine on Sandybridge, and only
if relocations are actually required to an active batch buffer.

Now we just need to teach the relocation code to handle physical
addressing for gen2/3, and we should then have universal support!
Suggested-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Testcase: igt/gem_exec_reloc/basic-spin # snb
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200501192945.22215-3-chris@chris-wilson.co.uk

As we can now keep chaining together a relocation batch to process any
number of relocations, we can keep building that relocation batch for
all of the target vma. This avoiding emitting a new request into the
ring for each target, consuming precious ring space and a potential
stall.

v2: Propagate the failure from submitting the relocation batch.

Testcase: igt/gem_exec_reloc/basic-wide-active
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200501192945.22215-2-chris@chris-wilson.co.uk

The ring is a precious resource: we anticipate to only use a few hundred
bytes for a request, and only try to reserve that before we start. If we
go beyond our guess in building the request, then instead of waiting at
the start of execbuf before we hold any locks or other resources, we
may trigger a wait inside a critical region. One example is in using gpu
relocations, where currently we emit a new MI_BB_START from the ring
every time we overflow a page of relocation entries. However, instead of
insert the command into the precious ring, we can chain the next page of
relocation entries as MI_BB_START from the end of the previous.

v2: Delay the emit_bb_start until after all the chained vma
synchronisation is complete. Since the buffer pool batches are idle, this
_should_ be a no-op, but one day we may some fancy async GPU bindings
for new vma!

v3: Use pool/batch consitently, once we start thinking in terms of the
batch vma, use batch->obj.
v4: Explain the magic number 4.

Tvrtko spotted that we lose propagation of the error for failing to
submit the relocation request; that's easier to fix up in the next
patch.

Testcase: igt/gem_exec_reloc/basic-many-active
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200501192945.22215-1-chris@chris-wilson.co.uk

When i915_gem_execbuffer2_ioctl() is using user_access_begin(),
that's only to perform unsafe_put_user() so use
user_write_access_begin() in order to only open write access.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ebf1250b6d4f351469fb339e5399d8b92aa8a1c1.1585898438.git.christophe.leroy@c-s.fr

Since the introduction of 'soft-rc6', we aim to park the device quickly
and that results in frequent idling of the whole device. Currently upon
idling we free the batch buffer pool, and so this renders the cache
ineffective for many workloads. If we want to have an effective cache of
recently allocated buffers available for reuse, we need to decouple that
cache from the engine powermanagement and make it timer based. As there
is no reason then to keep it within the engine (where it once made
retirement order easier to track), we can move it up the hierarchy to the
owner of the memory allocations.

v2: Hook up to debugfs/drop_caches to clear the cache on demand.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200430111819.10262-2-chris@chris-wilson.co.uk

The history of i915_vma_close() is confusing, as is its use. As the
lifetime of the i915_vma is currently bounded by the object it is
attached to, we needed a means of identify when a vma was no longer in
use by userspace (via the user's fd). This is further complicated by
that only ppgtt vma should be closed at the user's behest, as the ggtt
were always shared.

Now that we attach the vma to a lut on the user's context, the open
count does indicate how many unique and open context/vm are referencing
this vma from the user. As such, we can and should just use the
open_count to track when the vma is still in use by userspace.

It's a poor man's replacement for reference counting.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/1193Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200422190558.30509-1-chris@chris-wilson.co.uk

Tidy the code by casting remain to unsigned long once for the duration
of eb_relocate_vma()
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200407085930.19421-1-chris@chris-wilson.co.uk

__i915_gem_object_flush_map() takes a byte range, so feed it the written
bytes and do not mistake the u32 index as bytes!

Fixes: a679f58d ("drm/i915: Flush pages on acquisition")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: <stable@vger.kernel.org> # v5.2+
Reviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200406114821.10949-1-chris@chris-wilson.co.uk
(cherry picked from commit 30c88a47)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

If the user passes in a readonly reloc[], by the time we notice we have
already committed to modifying the execobjects, or have indeed done so
already. Reporting the failure just compounds the issue as we have no
second pass to fall back to anymore.

"Be damned if you do, and damned if you don't."

Testcase: igt/gem_exec_reloc/readonly
Fixes: 7dc8f114 ("drm/i915/gem: Drop relocation slowpath")
References: fddcd00a ("drm/i915: Force the slow path after a user-write error")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331162150.3635-1-chris@chris-wilson.co.uk
(cherry picked from commit 97a37c91)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

If we set the debug flag to force ourselves not to relocate via the gpu,
do not relocate via the gpu.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200406123616.7334-1-chris@chris-wilson.co.uk

__i915_gem_object_flush_map() takes a byte range, so feed it the written
bytes and do not mistake the u32 index as bytes!

Fixes: a679f58d ("drm/i915: Flush pages on acquisition")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: <stable@vger.kernel.org> # v5.2+
Reviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200406114821.10949-1-chris@chris-wilson.co.uk

If the current node/entry location is occupied, and the object is not
pinned, try assigning it some free space. We cannot wait here, so if in
doubt, we unreserve and try to grab all at once.

v2: Use the final pin_flags so that we won't have to move the object if
we find the wrong free space.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200401194135.5442-1-chris@chris-wilson.co.uk

If the user passes in a readonly reloc[], by the time we notice we have
already committed to modifying the execobjects, or have indeed done so
already. Reporting the failure just compounds the issue as we have no
second pass to fall back to anymore.

"Be damned if you do, and damned if you don't."

Testcase: igt/gem_exec_reloc/readonly
Fixes: 7dc8f114 ("drm/i915/gem: Drop relocation slowpath")
References: fddcd00a ("drm/i915: Force the slow path after a user-write error")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NAndi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331162150.3635-1-chris@chris-wilson.co.uk

Use a separate array allocation for the execbuf vma, so that we can
track their lifetime independently from the copy of the user arguments.
With luck, this has a secondary benefit of splitting the malloc size to
within reason and avoid vmalloc. The downside is that we might require
two separate vmallocs -- but much less likely.

In the process, this prevents a memory leak on the ww_mutex error
unwind.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1390Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330133710.14385-1-chris@chris-wilson.co.uk

A recent commit in clang added -Wtautological-compare to -Wall, which is
enabled for i915 after -Wtautological-compare is disabled for the rest
of the kernel so we see the following warning on x86_64:

 ../drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1433:22: warning:
 result of comparison of constant 576460752303423487 with expression of
 type 'unsigned int' is always false
 [-Wtautological-constant-out-of-range-compare]
         if (unlikely(remain > N_RELOC(ULONG_MAX)))
            ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
 ../include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
 # define unlikely(x)    __builtin_expect(!!(x), 0)
                                            ^
 1 warning generated.

It is not wrong in the case where ULONG_MAX > UINT_MAX but it does not
account for the case where this file is built for 32-bit x86, where
ULONG_MAX == UINT_MAX and this check is still relevant.

Cast remain to unsigned long, which keeps the generated code the same
(verified with clang-11 on x86_64 and GCC 9.2.0 on x86 and x86_64) and
the warning is silenced so we can catch more potential issues in the
future.

Closes: https://github.com/ClangBuiltLinux/linux/issues/778Suggested-by: NMichel Dänzer <michel@daenzer.net>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214054706.33870-1-natechancellor@gmail.com

I need to keep the GEM context around a bit longer so adding an explicit
flag for syncing execbuf with closed/abandonded contexts.

v2:
 * Use already available context flags. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319170707.8262-1-chris@chris-wilson.co.uk
(cherry picked from commit 207e4a71)
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

If the caller allows and we do not have to wait for any signals,
immediately execute the work within the caller's process. By doing so we
avoid the overhead of scheduling a new task, and the latency in
executing it, at the cost of pulling that work back into the immediate
context. (Sometimes we still prefer to offload the task to another cpu,
especially if we plan on executing many such tasks in parallel for this
client.)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200325120227.8044-2-chris@chris-wilson.co.uk

Drop the pretense of kicking the tasklet (used only for the defunct guc
submission backend, it should just take ownership of the submit!) and so
remove the bh-kicking from around submission.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323092841.22240-5-chris@chris-wilson.co.uk

As we store the handle lookup inside a radix tree, we do not need the
gem_context->mutex except until we need to insert our lookup into the
common radix tree. This takes a small bit of rearranging to ensure that
the lut we insert into the tree is ready prior to actually inserting it
(as soon as it is exposed via the radixtree, it is visible to any other
submission).

v2: For brownie points, remove the goto spaghetti.
v3: Tighten up the closed-handle checks.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323092841.22240-8-chris@chris-wilson.co.uk

I need to keep the GEM context around a bit longer so adding an explicit
flag for syncing execbuf with closed/abandonded contexts.

v2:
 * Use already available context flags. (Chris)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319170707.8262-1-chris@chris-wilson.co.uk

Since the relocations are no longer performed under a global
struct_mutex, or any other lock, that is also held by pagefault handlers,
we can relax and allow our fast path to take a fault. As we no longer
need to abort the fast path for lock avoidance, we no longer need the
slow path handling at all.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200311160310.26711-1-chris@chris-wilson.co.uk

The alignment is u64, and yet is_power_of_2() assumes unsigned long,
which might give different results between 32b and 64b kernel.
Signed-off-by: NMatthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305203534.210466-1-matthew.auld@intel.com
Cc: stable@vger.kernel.org
(cherry picked from commit 2920516b)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

We only need to serialise the multiple pinning during the eb_reserve
phase. Ideally this would be using the vm->mutex as an outer lock, or
using a composite global mutex (ww_mutex), but at the moment we are
using struct_mutex for the group.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/1381
Fixes: 003d8b91 ("drm/i915/gem: Only call eb_lookup_vma once during execbuf ioctl")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200306071614.2846708-3-chris@chris-wilson.co.uk