1. 23 6月, 2015 7 次提交
    • J
      drm/i915: Update add_request() to take a request structure · 75289874
      John Harrison 提交于
      Now that all callers of i915_add_request() have a request pointer to hand, it is
      possible to update the add request function to take a request pointer rather
      than pulling it out of the OLR.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      75289874
    • J
      drm/i915: Update queue_flip() to take a request structure · 6258fbe2
      John Harrison 提交于
      Updated the display page flip code to do explicit request creation and
      submission rather than relying on the OLR and just hoping that the request
      actually gets submitted at some random point.
      
      The sequence is now to create a request, queue the work to the ring, assign the
      known request to the flip queue work item then actually submit the work and post
      the request.
      
      Note that every single flip function used to finish with
      '__intel_ring_advance(ring);'. However, immediately after they return there is
      now an add request call which will do the advance anyway. Thus the many
      duplicate advance calls have been removed.
      
      v2: Updated commit message with comment about advance removal.
      
      v3: The request can now be allocated by the _sync() code earlier on. Thus the
      page flip path does not necessarily need to allocate a new request, it may be
      able to re-use one.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      6258fbe2
    • J
      drm/i915: Update render_state_init() to take a request structure · be01363f
      John Harrison 提交于
      Updated the two render_state_init() functions to take a request pointer instead
      of a ring. This removes their reliance on the OLR.
      
      v2: Rebased to newer tree.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      be01363f
    • J
      drm/i915: Update init_context() to take a request structure · 8753181e
      John Harrison 提交于
      Now that everything above has been converted to use requests, it is possible to
      update init_context() to take a request pointer instead of a ring/context pair.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      8753181e
    • J
      drm/i915: Update alloc_request to return the allocated request · 217e46b5
      John Harrison 提交于
      The alloc_request() function does not actually return the newly allocated
      request. Instead, it must be pulled from ring->outstanding_lazy_request. This
      patch fixes this so that code can create a request and start using it knowing
      exactly which request it actually owns.
      
      v2: Updated for new i915_gem_request_alloc() scheme.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      217e46b5
    • J
      drm/i915: i915_add_request must not fail · bf7dc5b7
      John Harrison 提交于
      The i915_add_request() function is called to keep track of work that has been
      written to the ring buffer. It adds epilogue commands to track progress (seqno
      updates and such), moves the request structure onto the right list and other
      such house keeping tasks. However, the work itself has already been written to
      the ring and will get executed whether or not the add request call succeeds. So
      no matter what goes wrong, there isn't a whole lot of point in failing the call.
      
      At the moment, this is fine(ish). If the add request does bail early on and not
      do the housekeeping, the request will still float around in the
      ring->outstanding_lazy_request field and be picked up next time. It means
      multiple pieces of work will be tagged as the same request and driver can't
      actually wait for the first piece of work until something else has been
      submitted. But it all sort of hangs together.
      
      This patch series is all about removing the OLR and guaranteeing that each piece
      of work gets its own personal request. That means that there is no more
      'hoovering up of forgotten requests'. If the request does not get tracked then
      it will be leaked. Thus the add request call _must_ not fail. The previous patch
      should have already ensured that it _will_ not fail by removing the potential
      for running out of ring space. This patch enforces the rule by actually removing
      the early exit paths and the return code.
      
      Note that if something does manage to fail and the epilogue commands don't get
      written to the ring, the driver will still hang together. The request will be
      added to the tracking lists. And as in the old case, any subsequent work will
      generate a new seqno which will suffice for marking the old one as complete.
      
      v2: Improved WARNings (Tomas Elf review request).
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      bf7dc5b7
    • J
      drm/i915: Reserve ring buffer space for i915_add_request() commands · 29b1b415
      John Harrison 提交于
      It is a bad idea for i915_add_request() to fail. The work will already have been
      send to the ring and will be processed, but there will not be any tracking or
      management of that work.
      
      The only way the add request call can fail is if it can't write its epilogue
      commands to the ring (cache flushing, seqno updates, interrupt signalling). The
      reasons for that are mostly down to running out of ring buffer space and the
      problems associated with trying to get some more. This patch prevents that
      situation from happening in the first place.
      
      When a request is created, it marks sufficient space as reserved for the
      epilogue commands. Thus guaranteeing that by the time the epilogue is written,
      there will be plenty of space for it. Note that a ring_begin() call is required
      to actually reserve the space (and do any potential waiting). However, that is
      not currently done at request creation time. This is because the ring_begin()
      code can allocate a request. Hence calling begin() from the request allocation
      code would lead to infinite recursion! Later patches in this series remove the
      need for begin() to do the allocate. At that point, it becomes safe for the
      allocate to call begin() and really reserve the space.
      
      Until then, there is a potential for insufficient space to be available at the
      point of calling i915_add_request(). However, that would only be in the case
      where the request was created and immediately submitted without ever calling
      ring_begin() and adding any work to that request. Which should never happen. And
      even if it does, and if that request happens to fall down the tiny window of
      opportunity for failing due to being out of ring space then does it really
      matter because the request wasn't doing anything in the first place?
      
      v2: Updated the 'reserved space too small' warning to include the offending
      sizes. Added a 'cancel' operation to clean up when a request is abandoned. Added
      re-initialisation of tracking state after a buffer wrap to keep the sanity
      checks accurate.
      
      v3: Incremented the reserved size to accommodate Ironlake (after finally
      managing to run on an ILK system). Also fixed missing wrap code in LRC mode.
      
      v4: Added extra comment and removed duplicate WARN (feedback from Tomas).
      
      For: VIZ-5115
      CC: Tomas Elf <tomas.elf@intel.com>
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      29b1b415
  2. 03 6月, 2015 3 次提交
  3. 22 5月, 2015 1 次提交
  4. 21 5月, 2015 3 次提交
    • C
      drm/i915: Implement inter-engine read-read optimisations · b4716185
      Chris Wilson 提交于
      Currently, we only track the last request globally across all engines.
      This prevents us from issuing concurrent read requests on e.g. the RCS
      and BCS engines (or more likely the render and media engines). Without
      semaphores, we incur costly stalls as we synchronise between rings -
      greatly impacting the current performance of Broadwell versus Haswell in
      certain workloads (like video decode). With the introduction of
      reference counted requests, it is much easier to track the last request
      per ring, as well as the last global write request so that we can
      optimise inter-engine read read requests (as well as better optimise
      certain CPU waits).
      
      v2: Fix inverted readonly condition for nonblocking waits.
      v3: Handle non-continguous engine array after waits
      v4: Rebase, tidy, rewrite ring list debugging
      v5: Use obj->active as a bitfield, it looks cool
      v6: Micro-optimise, mostly involving moving code around
      v7: Fix retire-requests-upto for execlists (and multiple rq->ringbuf)
      v8: Rebase
      v9: Refactor i915_gem_object_sync() to allow the compiler to better
      optimise it.
      
      Benchmark: igt/gem_read_read_speed
      hsw:gt3e (with semaphores):
      Before: Time to read-read 1024k:		275.794µs
      After:  Time to read-read 1024k:		123.260µs
      
      hsw:gt3e (w/o semaphores):
      Before: Time to read-read 1024k:		230.433µs
      After:  Time to read-read 1024k:		124.593µs
      
      bdw-u (w/o semaphores):             Before          After
      Time to read-read 1x1:            26.274µs       10.350µs
      Time to read-read 128x128:        40.097µs       21.366µs
      Time to read-read 256x256:        77.087µs       42.608µs
      Time to read-read 512x512:       281.999µs      181.155µs
      Time to read-read 1024x1024:    1196.141µs     1118.223µs
      Time to read-read 2048x2048:    5639.072µs     5225.837µs
      Time to read-read 4096x4096:   22401.662µs    21137.067µs
      Time to read-read 8192x8192:   89617.735µs    85637.681µs
      
      Testcase: igt/gem_concurrent_blit (read-read and friends)
      Cc: Lionel Landwerlin <lionel.g.landwerlin@linux.intel.com>
      Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
      Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> [v8]
      [danvet: s/\<rq\>/req/g]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      b4716185
    • I
      drm/i915/skl: enable WaForceContextSaveRestoreNonCoherent · 8ea6f892
      Imre Deak 提交于
      v2:
      - set the override disable flag too on stepping F0 (mika)
      Signed-off-by: NImre Deak <imre.deak@intel.com>
      Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      8ea6f892
    • I
      drm/i915/bxt: fix WaForceContextSaveRestoreNonCoherent on steppings B0+ · 2a0ee94f
      Imre Deak 提交于
      On B0 and C0 steppings the workaround enable bit would be overriden by
      default, so the overriding must be disabled.
      
      The WA was added in
      commit 83a24979
      Author: Nick Hoath <nicholas.hoath@intel.com>
      Date:   Fri Apr 10 13:12:26 2015 +0100
      
          drm/i915/bxt: Add WaForceContextSaveRestoreNonCoherent
      Spotted-by: NMika Kuoppala <mika.kuoppala@intel.com>
      Signed-off-by: NImre Deak <imre.deak@intel.com>
      Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      2a0ee94f
  5. 20 5月, 2015 1 次提交
  6. 08 5月, 2015 12 次提交
  7. 14 4月, 2015 2 次提交
  8. 10 4月, 2015 3 次提交
  9. 09 4月, 2015 1 次提交
  10. 07 4月, 2015 1 次提交
  11. 01 4月, 2015 2 次提交
    • J
      drm/i915: Fix for ringbuf space wait in LRC mode · dbe4646d
      John Harrison 提交于
      The legacy and LRC code paths have an almost identical procedure for waiting for
      space in the ring buffer. They both search for a request in the free list that
      will advance the tail to a point where sufficient space is available. They then
      wait for that request, retire it and recalculate the free space value.
      
      Unfortunately, a bug in the LRC side meant that the resulting free space might
      not be as large as expected and indeed, might not be sufficient. This is because
      it was testing against the value of request->tail not request->postfix. Whereas,
      when a request is retired, ringbuf->tail is updated to req->postfix not
      req->tail.
      
      Another significant difference between the two is that the LRC one did not trust
      the wait for request to work! It redid the is there enough space available test
      and would fail the call if insufficient. Whereas, the legacy version just said
      'return 0' - it assumed the preceeding code works. This difference meant that
      the LRC version still worked even with the bug - it just fell back to the
      polling wait path.
      
      For: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NThomas Daniel <thomas.daniel@intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      dbe4646d
    • J
      drm/i915: Move common request allocation code into a common function · 6689cb2b
      John Harrison 提交于
      The request allocation code is largely duplicated between legacy mode and
      execlist mode. The actual difference between the two versions of the code is
      pretty minimal.
      
      This patch moves the common code out into a separate function. This is then
      called by the execution specific version prior to setting up the one different
      value.
      
      For: VIZ-5190
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      Reviewed-by: NTomas Elf <tomas.elf@intel.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      6689cb2b
  12. 18 3月, 2015 2 次提交
  13. 26 2月, 2015 2 次提交
    • J
      drm/i915: Cache ringbuf pointer in request structure · 98e1bd4a
      John Harrison 提交于
      In execlist mode, the ringbuf is a function of the ring and context whereas in
      legacy mode, it is derived from the ring alone. Thus the calculation required to
      determine the ringbuf pointer from the ring (and context) also needs to test
      execlist mode or not. This is messy.
      
      Further, the request structure holds a pointer to both the ring and the context
      for which it was created. Thus, given a request, it is possible to derive the
      ringbuf in either legacy or execlist mode. Hence it is necessary to pass just
      the request in to all the low level functions rather than some combination of
      request, ring, context and ringbuf. However, rather than recalculating it each
      time, it is much simpler to just cache the ringbuf pointer in the request
      structure itself.
      
      Caching the pointer means the calculation is done once at request creation time
      and all further code and simply read it directly from the request structure.
      
      OTC-Jira: VIZ-5115
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      [danvet: Drop contentless comment in lrc alloc request entirely. And
      spelling fix in the commit message.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      98e1bd4a
    • J
      drm/i915: Rename 'flags' to 'dispatch_flags' for better code reading · 8e004efc
      John Harrison 提交于
      There is a flags word that is passed through the execbuffer code path all the
      way from initial decoding of the user parameters down to the very final dispatch
      buffer call. It is simply called 'flags'. Unfortuantely, there are many other
      flags words floating around in the same blocks of code. Even more once the GPU
      scheduler arrives.
      
      This patch makes it more obvious exactly which flags word is which by renaming
      'flags' to 'dispatch_flags'. Note that the bit definitions for this flags word
      already have an 'I915_DISPATCH_' prefix on them and so are not quite so
      ambiguous.
      
      OTC-Jira: VIZ-1587
      Signed-off-by: NJohn Harrison <John.C.Harrison@Intel.com>
      [danvet: Resolve conflict with Chris' rework of the bb parsing.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      8e004efc