Now that the request is guaranteed to specify the context, it is possible to
update the context switch code to use requests rather than ring and context
pairs. This patch updates i915_switch_context() accordingly.

Also removed the warning that the request's context must match the last context
switch's context. As the context switch now gets the context object from the
request structure, there is no longer any scope for the two to become out of
step.

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>

The final step in removing the OLR from i915_gem_init_hw() is to pass the newly
allocated request structure in to each step rather than passing a ring
structure. This patch updates both i915_ppgtt_init_ring() and
i915_gem_context_enable() to take request pointers.

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>

Now that a single per ring loop is being done for all the different
intialisation steps in i915_gem_init_hw(), it is possible to add proper request
management as well. The last remaining issue is that the context enable call
eventually ends up within *_render_state_init() and this does its own private
_i915_add_request() call.

This patch adds explicit request creation and submission to the top level loop
and removes the add_request() from deep within the sub-functions.

v2: Updated for removal of batch_obj from add_request call in previous patch.

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>

The start of day context initialisation code in i915_gem_context_enable() loops
over each ring and calls the legacy switch context or the execlist init context
code as appropriate.

This patch moves the ring looping out of that function in to the top level
caller i915_gem_init_hw(). This means the a single pass can be made over all
rings doing the PPGTT, L3 remap and context initialisation of each ring
altogether.

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>

In order to explcitly track all GPU work (and completely remove the outstanding
lazy request), it is necessary to add extra i915_add_request() calls to various
places. Some of these do not need the implicit cache flush done as part of the
standard batch buffer submission process.

This patch adds a flag to _add_request() to specify whether the flush is
required or not.

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>

The plan is to pass requests around as the basic submission tracking structure
rather than rings and contexts. This patch updates the
execbuffer_move_to_active() code path.

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>

Rather than just having a local request variable in the execbuff code, the
request pointer is now stored in the execbuff params structure. Also added
explicit cleanup of the request (plus wiping the OLR to match) in the error
case. This means that the execbuff code is no longer dependent upon the OLR
keeping track of the request so as to not leak it when things do go wrong. Note
that in the success case, the i915_add_request() at the end of the submission
function will tidy up the request and clear 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>

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>

Shrunk the parameter list of i915_gem_execbuffer_retire_commands() to a single
structure as everything it requires is available in the execbuff_params object.

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>

The do_execbuf() function takes quite a few parameters. The actual set of
parameters is going to change with the conversion to passing requests around.
Further, it is due to grow massively with the arrival of the GPU scheduler.

This patch simplifies the prototype by passing a parameter structure instead.
Changing the parameter set in the future is then simply a matter of
adding/removing items to the structure.

Note that the structure does not contain absolutely everything that is passed
in. This is because the intention is to use this structure more extensively
later in this patch series and more especially in the GPU scheduler that is
coming soon. The latter requires hanging on to the structure as the final
hardware submission can be delayed until long after the execbuf IOCTL has
returned to user land. Thus it is unsafe to put anything in the structure that
is local to the IOCTL call itself - such as the 'args' parameter. All entries
must be copies of data or pointers to structures that are reference counted in
some way and guaranteed to exist for the duration of the batch buffer's life.

v2: Rebased to newer tree and updated for changes to the command parser.
Specifically, a code shuffle has required saving the batch start address in the
params structure.

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>

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>

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>

We have enough generic hotplug functions sprinkled all over i915_irq.c
to warrant moving them to a file of their own. This should further
underline the distinction between generic code in the new file and
platform specific hotplug and irq code that remains in i915_irq.c.

Add new intel_hpd_init_work to keep work functions static, and rename
get_port_from_pin to intel_hpd_pin_to_port while increasing its
visibility, but keep everything else the same.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The skylake scalers depend on the cdclk freq, but that frequency can
change during a modeset. So when a modeset happens calculate the new
cdclk in the atomic state. With the transitional helpers gone the
cached value can be used in the scaler, and committed after all
crtc's are disabled.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90874Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because we're currently using FBC_UNSUPPORTED_MODE for two different
cases.

This commit will also allow us to write the next one without hiding
information from the user.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In igt, we want to test handling of GPU hangs, both for recovery
purposes and for reporting. However, we don't want to inject a genuine
GPU hang onto a machine that cannot recover and so be permenantly
wedged. Rather than embed heuristics into igt, have the kernel report
exactly when it expects the GPU reset to work.

This can also be usefully extended in future to indicate different
levels of fine-grained resets.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tim Gore <tim.gore@intel.com>
Cc: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Until now the software command checker assumed that commands could
read or write at most a single register per packet.  This is not
necessarily the case, MI_LOAD_REGISTER_IMM expects a variable-length
list of offset/value pairs and writes them in sequence.  The previous
code would only check whether the first entry was valid, effectively
allowing userspace to write unrestricted registers of the MMIO space
by sending a multi-register write with a legal first register, with
potential security implications on Gen6 and 7 hardware.

Fix it by extending the drm_i915_cmd_descriptor table to represent
multi-register access and making validate_cmd() iterate for all
register offsets present in the command packet.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Until now the software command checker assumed that commands could
read or write at most a single register per packet.  This is not
necessarily the case, MI_LOAD_REGISTER_IMM expects a variable-length
list of offset/value pairs and writes them in sequence.  The previous
code would only check whether the first entry was valid, effectively
allowing userspace to write unrestricted registers of the MMIO space
by sending a multi-register write with a legal first register, with
potential security implications on Gen6 and 7 hardware.

Fix it by extending the drm_i915_cmd_descriptor table to represent
multi-register access and making validate_cmd() iterate for all
register offsets present in the command packet.
Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Reviewed-by: NZhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we can subclass drm_atomic_state we can also use it to keep
track of all the pll settings. atomic_state is a better place to hold
all shared state than keeping pll->new_config everywhere.

Changes since v1:
- Assert connection_mutex is held.
Changes since v2:
- Fix swapped arguments to kzalloc for intel_atomic_state_alloc. (Jani Nikula)
Signed-off-by: NAnder Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Now that the dpll updates are (mostly) atomic, the .off() code is a noop,
and intel_crtc_disable does mostly the same as intel_modeset_update_state.

Move all logic for connectors_active and setting dpms to that function.

Changes since v1:
- Move drm_atomic_helper_swap_state up.
Changes since v2:
- Split out intel_put_shared_dpll removal.
Changes since v3:
- Rebase on top of latest drm-intel.
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

We need to tell BDW ULT and ULX apart.

v2: Rebased to the latest
v3: Rebased to the latest
v4: Fix for patch style problems
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kahola <mika.kahola@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

Keep the cdclk maximum supported frequency around in dev_priv so that we
can verify certain things against it before actually changing the cdclk
frequency.

For now only VLV/CHV have support changing cdclk frequency, so other
plarforms get to assume cdclk is fixed.

v2: Rebased to the latest
v3: Rebased to the latest
v4: Fix for patch style problems
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NMika Kahola <mika.kahola@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There are plenty of hotplug related fields in struct drm_i915_private
scattered all around. Group them under one hotplug struct. Clean up
naming while at it. No functional changes.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Export a new context parameter that can be set/queried through the
context_{get,set}param ioctls.  This parameter is passed as a context
flag and decides whether or not a GPU address mapping is allowed to
be made at address zero.  The default is to allow such mappings.
Signed-off-by: NDavid Weinehall <david.weinehall@intel.com>
Acked-by: N"Zou, Nanhai" <nanhai.zou@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Rename dpio_lock to sb_lock to inform the reader that its primary
purpose is to protect the sideband mailbox rather than some DPIO
state.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In commit 1854d5ca
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Tue Apr 7 16:20:32 2015 +0100

    drm/i915: Deminish contribution of wait-boosting from clients

we removed an atomic timer based check for allowing waitboosting and
moved it below the mutex taken during RPS. However, that mutex can be
held for long periods of time on Vallyview/Cherryview as communication
with the PCU is slow. As clients may frequently wait for results (e.g.
such as tranform feedback) we introduced contention between the client
and the RPS worker. We can take advantage of the RPS worker, by
switching the wait boost decision to use spin locks and defer the
actual reclocking to the worker.

Fixes a regression of up to 45% on Baytrail and Baswell!

v2 (Daniel):
- Use max_freq_softlimit instead of the not-yet-merged boost
  frequency.
- Don't inject a fake irq into the boost work, instead treat
  client_boost as just another legit waker.

v3: Drop the now unused mask (Chris).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=90112
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As Daniel commented on

commit b7ffe1362c5f468b853223acc9268804aa92afc8
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Apr 27 13:41:24 2015 +0100

    drm/i915: Free RPS boosts for all laggards

it is better to be explicit when sharing hardcoded values such as
throttle/boost timeouts. Make it so!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to re-init the display hardware when going out of suspend. This
includes:

  - Hooking the PCH to the reset logic
  - Restoring CDCDLK
  - Enabling the DDB power

Among those, only the CDCDLK one is a bit tricky. There's some
complexity in that:

  - DPLL0 (which is the source for CDCLK) has two VCOs, each with a set
    of supported frequencies. As eDP also uses DPLL0 for its link rate,
    once DPLL0 is on, we restrict the possible eDP link rates the chosen
    VCO.
  - CDCLK also limits the bandwidth available to push pixels.

So, as a first step, this commit restore what the BIOS set, until I can
do more testing.

In case that's of interest for the reviewer, I've unit tested the
function that derives the decimal frequency field:

  #include <stdio.h>
  #include <stdint.h>
  #include <assert.h>

  #define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))

  static const struct dpll_freq {
          unsigned int freq;
          unsigned int decimal;
  } freqs[] = {
          { .freq = 308570, .decimal = 0b01001100111},
          { .freq = 337500, .decimal = 0b01010100001},
          { .freq = 432000, .decimal = 0b01101011110},
          { .freq = 450000, .decimal = 0b01110000010},
          { .freq = 540000, .decimal = 0b10000110110},
          { .freq = 617140, .decimal = 0b10011010000},
          { .freq = 675000, .decimal = 0b10101000100},
  };

  static void intbits(unsigned int v)
  {
          int i;

          for(i = 10; i >= 0; i--)
                  putchar('0' + ((v >> i) & 1));
  }

  static unsigned int freq_decimal(unsigned int freq /* in kHz */)
  {
          return (freq - 1000) / 500;
  }

  static void test_freq(const struct dpll_freq *entry)
  {
          unsigned int decimal = freq_decimal(entry->freq);

          printf("freq: %d, expected: ", entry->freq);
          intbits(entry->decimal);
          printf(", got: ");
          intbits(decimal);
          putchar('\n');

          assert(decimal == entry->decimal);
  }

  int main(int argc, char **argv)
  {
          int i;

          for (i = 0; i < ARRAY_SIZE(freqs); i++)
                  test_freq(&freqs[i]);

          return 0;
  }

v2:
  - Rebase on top of -nightly
  - Use (freq - 1000) / 500 for the decimal frequency (Ville)
  - Fix setting the enable bit of HSW_NDE_RSTWRN_OPT (Ville)
  - Rename skl_display_{resume,suspend} to skl_{init,uninit}_cdclk to
    be consistent with the BXT code (Ville)
  - Store boot CDCLK in ddi_pll_init (Ville)
  - Merge dev_priv's skl_boot_cdclk into cdclk_freq
  - Use LCPLL_PLL_LOCK instead of (1 << 30) (Ville)
  - Replace various '0' by SKL_DPLL0 to be a bit more explicit that
    we're programming DPLL0
  - Busy poll the PCU before doing the frequency change. It takes about
    3/4 cycles, each separated by 10us, to get the ACK from the CPU
    (Ville)

v3:
  - Restore dev_priv->skl_boot_cdclk, leaving unification with
    dev_priv->cdclk_freq for a later patch (Daniel, Ville)
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we have internal clients, rather than faking a whole
drm_i915_file_private just for tracking RPS boosts, create a new struct
intel_rps_client and pass it along when waiting.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: s/rq/req/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since we will often pageflip to an active surface, we will often have to
wait for the surface to be written before issuing the flip. Also we are
likely to wait on that surface in plenty of time before the vblank.
Since we have a mechanism for boosting when a flip misses the expected
vblank, curtain the number of times we RPS boost when simply waiting for
mmioflip.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: s/rq/req/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ring switches can occur many times per frame, and are often out of
control, causing frequent RPS boosting for no practical benefit. Treat
the sw semaphore synchronisation as a separate client and only allow it
to boost once per busy/idle cycle.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: s/rq/req/]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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>

Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

BUN 1: prop_coeff, int_coeff, tdctargetcnt programming updated and tied to
VCO frequencies. Program i_lockthresh in PORT_PLL_9.

VCO calculated based on the formula:
Desired Output = Port bit rate in MHz (DisplayPort HBR2 is 5400 MHz)
Fast Clock = Desired Output / 2
VCO = Fast Clock * P1 * P2

Prop_coeff, int_coeff, and tdctargetcnt modified according to above
calculation.

BUN 2: Port PLLs require additional programming at certain frequencies -
DCO amplitude in PORT_PLL_10

Review comments from Siva which were addressed in the initial version of the
patch.
	- Change PORT_PLL_LOCK_THRESHOLD to PORT_PLL_LOCK_THRESHOLD_MASK
	- Calculate for HDMI
	- Correct values for vco = 5.4
	- return in case of invalid vco range

v2: Imre's review comments addressed
	- change dcoampovr_en to dcoampovr_en_h
	- change PORT_PLL_DCO_AMP_OVR_EN to PORT_PLL_DCO_AMP_OVR_EN_H
	- Correct lane stagger value for 324MHz
	- Make coef common for HDMI and DP
	- remove superfluous comments

v3: Imre's comments addressed
	- Remove Prop_coeff, int_coeff, tdctargetcnt, dcoampovr_en, gain_ctl,
	dcoampovr_en_h from bxt_clk_div and make them local variables.
Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com> [v1]
Cc: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Be in line with other features that we have.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As we perform the mmio-flip without any locking and then try to acquire
the struct_mutex prior to dereferencing the request, it is possible for
userspace to queue a new pageflip before the worker can finish clearing
the old state - and then it will clear the new flip request. The result
is that the new flip could be completed before the GPU has finished
rendering.

The bugs stems from removing the seqno checking in
commit 536f5b5e
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Thu Nov 6 11:03:40 2014 +0200

    drm/i915: Make mmio flip wait for seqno in the work function
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We no longer interpolate domains in the same manner, and even if we did,
we should trust setting either of the other write domains would trigger
an invalidation rather than force it. Remove the tweaking of the
read_domains since it serves no purpose and use
i915_gem_object_wait_rendering() directly.

Note that this goes back to

commit a8198eea
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed Apr 13 22:04:09 2011 +0100

    drm/i915: Introduce i915_gem_object_finish_gpu()

and gpu domain tracking died in

commit cc889e0f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Jun 13 20:45:19 2012 +0200

    drm/i915: disable flushing_list/gpu_write_list

which is more than 1 year older.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add notes with information dug out of git history.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>