8 Commits

Author SHA1 Message Date
Maarten Lankhorst
1832f886ba drm/i915/selftests: Prepare execbuf tests for obj->mm.lock removal.
Also quite simple, a single call needs to use the unlocked version.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-47-maarten.lankhorst@linux.intel.com
2021-03-24 17:41:23 +01:00
Maarten Lankhorst
47b086934f drm/i915: Make sure execbuffer always passes ww state to i915_vma_pin.
As a preparation step for full object locking and wait/wound handling
during pin and object mapping, ensure that we always pass the ww context
in i915_gem_execbuffer.c to i915_vma_pin, use lockdep to ensure this
happens.

This also requires changing the order of eb_parse slightly, to ensure
we pass ww at a point where we could still handle -EDEADLK safely.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-15-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07 14:31:13 +03:00
Maarten Lankhorst
2bf541ff6d drm/i915: Pin engine before pinning all objects, v5.
We want to lock all gem objects, including the engine context objects,
rework the throttling to ensure that we can do this. Now we only throttle
once, but can take eb_pin_engine while acquiring objects. This means we
will have to drop the lock to wait. If we don't have to throttle we can
still take the fastpath, if not we will take the slowpath and wait for
the throttle request while unlocked.

The engine has to be pinned as first step, otherwise gpu relocations
won't work.

Changes since v1:
- Only need to get a throttled request in the fastpath, no need for
  a global flag any more.
- Always free the waited request correctly.
Changes since v2:
- Use intel_engine_pm_get()/put() to keeep engine pool alive during
  EDEADLK handling.
Changes since v3:
- Fix small rq leak.
Changes since v4:
- Use a single reloc_context, for intel_context_pin_ww().

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-13-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07 14:30:52 +03:00
Maarten Lankhorst
c43ce12328 drm/i915: Use per object locking in execbuf, v12.
Now that we changed execbuf submission slightly to allow us to do all
pinning in one place, we can now simply add ww versions on top of
struct_mutex. All we have to do is a separate path for -EDEADLK
handling, which needs to unpin all gem bo's before dropping the lock,
then starting over.

This finally allows us to do parallel submission, but because not
all of the pinning code uses the ww ctx yet, we cannot completely
drop struct_mutex yet.

Changes since v1:
- Keep struct_mutex for now. :(
Changes since v2:
- Make sure we always lock the ww context in slowpath.
Changes since v3:
- Don't call __eb_unreserve_vma in eb_move_to_gpu now; this can be
  done on normal unlock path.
- Unconditionally release vmas and context.
Changes since v4:
- Rebased on top of struct_mutex reduction.
Changes since v5:
- Remove training wheels.
Changes since v6:
- Fix accidentally broken -ENOSPC handling.
Changes since v7:
- Handle gt buffer pool better.
Changes since v8:
- Properly clear variables, to make -EDEADLK handling not BUG.
Change since v9:
- Fix unpinning fence on pnv and below.
Changes since v10:
- Make relocation gpu chaining working again.
Changes since v11:
- Remove relocation chaining, pain to make it work.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-9-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07 14:30:07 +03:00
Maarten Lankhorst
50ae6c61a1 drm/i915: Revert relocation chaining commits.
This reverts commit 964a9b0f611ee ("drm/i915/gem: Use chained reloc batches")
and commit 0e97fbb080553 ("drm/i915/gem: Use a single chained reloc batches
for a single execbuf").

When adding ww locking to execbuf, it's hard enough to deal with a
single BO that is part of relocation execution. Chaining is hard to
get right, and with GPU relocation deprecated, it's best to drop this
altogether, instead of trying to fix something we will remove.

This is not a completely 1:1 revert, we reset rq_size to 0 in
reloc_cache_init, this was from e3d291301f99 ("drm/i915/gem: Implement legacy
MI_STORE_DATA_IMM"), because we don't want to break the selftests. (Daniel)

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-3-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07 14:29:07 +03:00
Maarten Lankhorst
102a0a9051 Revert "drm/i915/gem: Async GPU relocations only"
This reverts commit 9e0f9464e2ab ("drm/i915/gem: Async GPU relocations only"),
and related commit 7ac2d2536dfa7 ("drm/i915/gem: Delete unused code").

Async GPU relocations are not the path forward, we want to remove
GPU accelerated relocation support eventually when userspace is fixed
to use VM_BIND, and this is the first step towards that. We will keep
async gpu relocations around for now, until userspace is fixed.

Relocation support will be disabled completely on platforms where there
was never any userspace that depends on it, as the hardware doesn't
require it from at least gen9+ onward. For older platforms, the plan
is to use cpu relocations only.

The igt side is fixed in igt commit 39e9aa1032a4e ("tests/i915: Remove
subtests that rely on async relocation behavior").

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-2-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-09-07 14:28:46 +03:00
Chris Wilson
9e0f9464e2 drm/i915/gem: Async GPU relocations only
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: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200604211457.19696-1-chris@chris-wilson.co.uk
2020-06-05 09:45:44 +01:00
Chris Wilson
e3d291301f drm/i915/gem: Implement legacy MI_STORE_DATA_IMM
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/757
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/20200504140629.28240-1-chris@chris-wilson.co.uk
2020-05-04 15:15:04 +01:00