linux-toradex.git/drivers/gpu/drm/i915/intel_ringbuffer.h, branch v4.4.44

drm/i915: Refactor common ringbuffer allocation code

2015-09-04T08:17:00+00:00

A small, very small, step to sharing the duplicate code between
execlists and legacy submission engines, starting with the ringbuffer
allocation code.

Signed-off-by: Chris Wilson 
Cc: Arun Siluvery 
Cc: Mika Kuoppala 
Cc: Dave Gordon 
Reviewed-by: Paulo Zanoni 
Reviewed-by: Mika Kuoppala 
Signed-off-by: Daniel Vetter

drm/i915/bxt: work around HW coherency issue when accessing GPU seqno

2015-08-26T07:39:13+00:00

By running igt/store_dword_loop_render on BXT we can hit a coherency
problem where the seqno written at GPU command completion time is not
seen by the CPU. This results in __i915_wait_request seeing the stale
seqno and not completing the request (not considering the lost
interrupt/GPU reset mechanism). I also verified that this isn't a case
of a lost interrupt, or that the command didn't complete somehow: when
the coherency issue occured I read the seqno via an uncached GTT mapping
too. While the cached version of the seqno still showed the stale value
the one read via the uncached mapping was the correct one.

Work around this issue by clflushing the corresponding CPU cacheline
following any store of the seqno and preceding any reading of it. When
reading it do this only when the caller expects a coherent view.

v2:
- fix using the proper logical && instead of a bitwise & (Jani, Mika)
- limit the workaround to A stepping, on later steppings this HW issue
  is fixed
v3:
- use a separate get_seqno/set_seqno vfunc (Chris)

Testcase: igt/store_dword_loop_render
Signed-off-by: Imre Deak 
Reviewed-by: Chris Wilson 
Signed-off-by: Daniel Vetter

Merge tag 'drm-intel-fixes-2015-07-15' into drm-intel-next-queued

2015-07-15T14:36:50+00:00

Backmerge fixes since it's getting out of hand again with the massive
split due to atomic between -next and 4.2-rc. All the bugfixes in
4.2-rc are addressed already (by converting more towards atomic
instead of minimal duct-tape) so just always pick the version in next
for the conflicts in modeset code.

All the other conflicts are just adjacent lines changed.

Conflicts:
	drivers/gpu/drm/i915/i915_drv.h
	drivers/gpu/drm/i915/i915_gem_gtt.c
	drivers/gpu/drm/i915/intel_display.c
	drivers/gpu/drm/i915/intel_drv.h
	drivers/gpu/drm/i915/intel_ringbuffer.h

Signed-off-by: Daniel Vetter

drm/i915: Snapshot seqno of most recently submitted request.

2015-07-13T20:42:39+00:00

The hang checker needs to inspect whether or not the ring request list is empty
as well as if the given engine has reached or passed the most recently
submitted request. The problem with this is that the hang checker cannot grab
the struct_mutex, which is required in order to safely inspect requests since
requests might be deallocated during inspection. In the past we've had kernel
panics due to this very unsynchronized access in the hang checker.

One solution to this problem is to not inspect the requests directly since
we're only interested in the seqno of the most recently submitted request - not
the request itself. Instead the seqno of the most recently submitted request is
stored separately, which the hang checker then inspects, circumventing the
issue of synchronization from the hang checker entirely.

This fixes a regression introduced in

commit 44cdd6d219bc64f6810b8ed0023a4d4db9e0fe68
Author: John Harrison 
Date:   Mon Nov 24 18:49:40 2014 +0000

    drm/i915: Convert 'ring_idle()' to use requests not seqnos

v2 (Chris Wilson):
- Pass current engine seqno to ring_idle() from i915_hangcheck_elapsed() rather
than compute it over again.
- Remove extra whitespace.

Issue: VIZ-5998
Signed-off-by: Tomas Elf 
Cc: stable@vger.kernel.org
Reviewed-by: Chris Wilson 
[danvet: Add regressing commit citation provided by Chris.]
Signed-off-by: Daniel Vetter

drm/i915: Enable resource streamer bits on MI_BATCH_BUFFER_START

2015-07-06T08:25:57+00:00

Adds support for enabling the resource streamer on the legacy
ringbuffer for HSW and GEN8.

Reviewed-by: Chris Wilson 
Signed-off-by: Abdiel Janulgue 
Signed-off-by: Daniel Vetter

drm/i915: Reserve space improvements

2015-07-03T05:38:59+00:00

An earlier patch was added to reserve space in the ring buffer for the
commands issued during 'add_request()'. The initial version was
pessimistic in the way it handled buffer wrapping and would cause
premature wraps and thus waste ring space.

This patch updates the code to better handle the wrap case. It no
longer enforces that the space being asked for and the reserved space
are a single contiguous block. Instead, it allows the reserve to be on
the far end of a wrap operation. It still guarantees that the space is
available so when the wrap occurs, no wait will happen. Thus the wrap
cannot fail which is the whole point of the exercise.

Also fixed a merge failure with some comments from the original patch.

v2: Incorporated suggestion by David Gordon to move the wrap code
inside the prepare function and thus allow a single combined
wait_for_space() call rather than doing one before the wrap and
another after. This also makes the prepare code much simpler and
easier to follow.

v3: Fix for 'effective_size' vs 'size' during ring buffer remainder
calculations (spotted by Tomas Elf).

For: VIZ-5115
CC: Daniel Vetter 
Signed-off-by: John Harrison 
Reviewed-by: Tomas Elf 
Signed-off-by: Daniel Vetter

drm/i915: Remove the now obsolete 'outstanding_lazy_request'

2015-06-23T12:02:32+00:00

The outstanding_lazy_request is no longer used anywhere in the driver.
Everything that was looking at it now has a request explicitly passed in from on
high. Everything that was relying upon it behind the scenes is now explicitly
creating/passing/submitting its own private request. Thus the OLR can be
removed.

For: VIZ-5115
Signed-off-by: John Harrison 
Reviewed-by: Tomas Elf 
Signed-off-by: Daniel Vetter

drm/i915: Remove the now obsolete intel_ring_get_request()

2015-06-23T12:02:31+00:00

Much of the driver has now been converted to passing requests around instead of
rings/ringbufs/contexts. Thus the function for retreiving the request from a
ring (i.e. the OLR) is no longer used and can be removed.

For: VIZ-5115
Signed-off-by: John Harrison 
Reviewed-by: Tomas Elf 
Signed-off-by: Daniel Vetter

drm/i915: Add *_ring_begin() to request allocation

2015-06-23T12:02:30+00:00

Now that the *_ring_begin() functions no longer call the request allocation
code, it is finally safe for the request allocation code to call *_ring_begin().
This is important to guarantee that the space reserved for the subsequent
i915_add_request() call does actually get reserved.

v2: Renamed functions according to review feedback (Tomas Elf).

For: VIZ-5115
Signed-off-by: John Harrison 
Signed-off-by: Daniel Vetter

drm/i915: Update intel_ring_begin() to take a request structure

2015-06-23T12:02:29+00:00

Now that everything above has been converted to use requests, intel_ring_begin()
can be updated to take a request instead of a ring. This also means that it no
longer needs to lazily allocate a request if no-one happens to have done it
earlier.

For: VIZ-5115
Signed-off-by: John Harrison 
Reviewed-by: Tomas Elf 
Signed-off-by: Daniel Vetter