New GuC code is logging errors at runtime suspend and resume which
causes CI testing to log "orange" status. Default to not trying to
load the firmware until this is resolved.

Example of the log:

 [drm] RC6 on
 [drm:intel_runtime_suspend] Suspending device
 [drm:host2guc_action [i915]] *ERROR* GUC: host2guc action 0x501 failed. ret=-110 status=0x00000501 response=0x40000000
 ...
 [drm:intel_runtime_resume] Resuming device
 [drm:host2guc_action [i915]] *ERROR* GUC: host2guc action 0x502 failed. ret=-110 status=0x00000502 response=0x40000000
 [drm:intel_runtime_resume] Device resumed
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Harris <chris.harris@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1464017675-12257-1-git-send-email-tvrtko.ursulin@linux.intel.com

Like with cdclk, the DMC is supposed to manage dbuf enabling/disabling.
Let's make sure it has correctly restored the dbuf state to enabled
when we disable the DC states.

v2: s/skl/gen9/ in function name (Imre)

Cc: Imre Deak <imre.deak@intel.com>
Suggested-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463407180-28993-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

In case the driver is initialized without active displays, we should
just drop the cdclk to the minimum frequency right off the bat. There
might not be a modeset to drop it to the minimum late rafter all.

With DMC supposedly we should always have the cdclk up and running.
The DMC will shut the DE PLL down when appropriate, so let's nuke
the related FIXMEs as well. Trying to do anything different would
go against the expectations of the DMC firmware, and we all know
how fragile the DMC firmware is.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-22-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Rather than having a BXT specific function to make sure the DE PLL is
enabled after disabling DC6, let's just make sure the current cdclk
is the same as what we last programmed.

Having another check in bxt_display_core_init() almost immediately after
the cdclk init seems redundant, so let's just kill that one.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-21-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Make bxt_set_cdclk() more readable by looking at current vs. target
DE PLL vco to determine if the DE PLL needs disabling and/or enabling.
We can also calculate the CD2X divider simply as (vco/cdclk) instead of
depending on magic numbers.

The magic numbers are still needed though, but only to map the supported
cdclk frequencies to corresponding DE PLL frequencies.

Note that w'll now program CDCLK_CTL correctly even for the bypass case.
Actually the CD2X divider should not matter in that case since the
hardware will bypass it too, but the "decimal" part should matter (if we
want to do gmbus/aux with the bypass enabled).
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-20-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Now that we've read out the DE PLL vco and refclk, we can just use them
in the cdclk calculation. While at it switch over to
DIV_ROUND_CLOSEST().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-19-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Let's make sure our cached cdclk state is accurate right after
broxton_init_cdclk() whether or not we end up changing the cdclk
frequency.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-18-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

We have need to know the DE PLL refclk and output frequency in various
cdclk calculations, so let's store those in dev_priv.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-17-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Enabling and disalbing the DE PLL are two nice self contained
operations, so let's move them into a few small helper functions.
Makes it easier to see the forest from the trees in broxton_set_cdclk().
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-16-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Future platforms will have multiple options for the cdclk PLL reference
clock, so let's start tracking that under dev_priv alreday on SKL,
although on SKL it's always 24 MHz.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-15-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

We'll want to store the cdclk PLL (whatever PLL that is in reality) vco
frequency somewhere on other platforms too, so let's rename the
skl_vco_freq to cdclk_pll.vco, and let's store it in kHz instead of MHz
to match most of the other clocks.

v2: Drop the spurious > vs != change (Imre)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-14-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

The SKL 308.57 MHz cdclk is probably 8640/28 = ~308.571 Mhz.
Similartly the 617.14 MHz cdclk is probably 8640/14 = ~617.143 MHz.
Let's use the slightly more accurate numbers. Potentially we might
change to computing all of these based on dividers, but let's
stick to the current theme for now..
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-13-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

SKL and BXT have the same snippets of code for enabling disabling the
DBUF. Extract those into helpers and move the calls from
init/unit_cdclk() to the display core init/init since this stuff isn't
really about cdclk. Also doing the enable twice shouldn't hurt since
you're just setting the request bit again when it was already set.

We can also toss in a few WARNs about the register values into
skl_get_dpll0_vco() now that we know that things should always be
sane there.

Flatten skl_init_cdclk() while at it.

v2: s/skl/gen9/ in function names (Imre)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-12-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Currently we initialize cdclk on SKL from two different places,
depending on whether it's during driver init or resume. Let's
unify it to happen from the same place always, and that place will be
the display core init function.

To do this we first run through the cdclk sanitation code, which will
first verify that the PLL is programmed correctly, after which we can
read out the current cdclk frequency, and once the cdclk is known we
verify that the cdclk "decimal" frequency is programmed correctly. If
any of these fail we will force a cdclk change, and to be safe we also
force the PLL to be turned off and on again. If the sanitation step
didn't notice anything amiss, we'll skip the cdclk programming which
will prevent cdclk reprogramming when the displays might be active.

We can also toss in a few WARNs about the register values into
skl_update_dpll0() since we now know that the PLL state should
always be sane when that function is called.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-11-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Also verify the DPLL_CTRL1 register value in skl_sanitize_cdclk(), throw
out a few unneeded variables, and write the CDCLK_CTL check a bit more
legible way.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-10-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Now that skl_vco_freq tracks the actual DPLL0 vco frequency, we'll need
something that keeps track of which vco frequency we want to use in case
the current vco is 0. This would be important across supend/resume since
we'll disable DPLL0 around those parts.

We'll also update our idea of max cdclk/dotclock when the preferred
vco changes. That could happen if out initial guess was wrong, and
later eDP would force us to change it. One issue here could be that
changing the max dotclock could cause our mode list to change during
next time the displays get probed. But I don't see a good way to avoid
that, except perhaps by allowing either vco frequency to be used as
needed. But the docs suggest that such usage wasn't really inteded.

Also need to make sure we don't update our max_cdclk value before we
have a preferred vco value, which means moving that to happen after
the cdclk sanitation.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-9-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

In case we originally guessed wrong which lcpll vco frequency to use,
we will need to shut down the pll and restart it when reprogamming the
cdclk.

This also allows us to track the actual vco frequency in dev_priv
instead of just a guess.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-8-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-7-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Currently we're trying to guess which lcpll vco frequency is used
use based on the cdclk. That doesn't work for cdclk==540 since
both vco frequencies can generate a 540 Mhz output. Let's stop
guessing and just read the actual vco frequency from the
hardware.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-6-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

We have many places where we want to pick a suitable cdclk frequency for
skl based on the dotclock and lcpll vco. Split that code into a small
helper and call it from all over.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Shared plls won't get assigned until the .compute_clocks() hook gets
called, which happens from the crtc .atomic_check hook. That's too late
as the cdclk computation has already happened. So let's move the DPLL0
VCO computation into intel_dp_compute_config() so that it's done when
the cdclk computation happens. Also only do it for eDP since we only
pick DPLL0 for eDP.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

WARNING: Using ChromeOS with an eDP panel and a 4K@60 DP monitor connected
to DDI1 the system will hard hang during a cold boot. Occurs when DDI1
is enabled when the cdclk is less then required. DP connected to DDI2
and HPD on either port works correctly.

Set cdclk based on the max required pixel clock based on VCO
selected. Track boot vco instead of boot cdclk.

The vco is now tracked at the atomic level and all CRTCs updated if
the required vco is changed. Not tested with eDP v1.4 panels that
require 8640 vco due to availability.

V1: initial version
V2: add vco tracking in intel_dp_compute_config(), rename
skl_boot_cdclk.
V3: rebase, V2 feedback not possible as encoders are not aware of
atomic.
V4: track target vco is atomic state. modeset all CRTCs if vco changes
V5: rename atomic variable, cleaner if/else logic, use existing vco if
      encoder does not return a new vco value. check_patch.pl cleanup
V6: simplify logic in intel_modeset_checks.
V7: reorder an IF for readability and whitespace fix.
V8: use dev_cdclk for tracking new cdclk during atomic
V9: correctly handle vco 8640 when crtcs==0
V10: Clean up if else in crtcs==0
V11: Rebase for new intel_dpll_mgr.c
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NClint Taylor <clinton.a.taylor@intel.com>
[vsyrjala: rebased due to churn]
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-3-git-send-email-ville.syrjala@linux.intel.com

commit 4e5ca60f ("drm/i915: Use ilk_max_pixel_rate() for BXT cdclk calculation")
tried to change BXT to use ilk_max_pixel_rate() to compute the
pipe pixel rate. I failed to notice that there was another place
in the state readout code that needs the same treatment. So let's
change that one too.

Should probably just change things to always compuyte the pipe pixel
rates, instead of just doing on platforms that can change cdclk
dynamically. But for now let's just move BXT fully over to the
side that uses ilk_pipe_pixel_rate().

Cc: Jani Nikula <jani.nikula@intel.com>
Fixes: 4e5ca60f ("drm/i915: Use ilk_max_pixel_rate() for BXT cdclk calculation")
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NImre Deak <imre.deak@intel.com>

Current intel_opregion_init is called during the driver registration
phase and intel_opregion_fini from the unregistration phase. Rename the
functions so that this is clear from their names. The phases tell us
what we expect the existing hw state to be, e.g. whether interrupts are
still enabled etc.

It should be noted that the opregion init/fini routines are asymmetric
and this is carried across into their new names. Indeed, their new names
make it even clearer that perhaps all is not well in the opregion
suspend/resume sequence (as well in the module unload).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464012490-30961-2-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJani Nikula <jani.nikula@linux.intel.com>

Prefer passing struct drm_i915_private to internal interfaces as this
saves us having to dance between drm_device and our native struct. The
savings hare are small (only 70 bytes of unrequired dancing), but
progressive!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464012490-30961-1-git-send-email-chris@chris-wilson.co.ukReviewed-by: NJani Nikula <jani.nikula@linux.intel.com>

We've never actually enabled or unmasked the GSE interrupt on BDW+,
even though the interrupt handler was always prepared for it.
Let's enable it and see what happens.

Credit to Mark Kettenis who fixed this in the OpenBSD fork of the
driver. He reports that it fixed the "ACPI _BCM/_BCQ-based
brightness mechanism on a MacBookPro12,1 and a 3rd gen Lenovo X1
Carbon" for them.

Mark says:
"FWIW, this *is* needed if you want ACPI-based backlight control to
 work.  On Linux you probably don't notice, since "hardware" backlight
 control is preferred over "firmware" or "platform" backlight control.

 It would help me if this did land in the Linux tree though, as it will
 make future imports of the i915 driver into OpenBSD easier."

So even though we don't really need this, let's put it in to help Mark
with future porting efforts. Should be harmless to have it enabled in
any case.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
References: http://lists.freedesktop.org/archives/intel-gfx/2015-December/081799.htmlReported-by: NMark Kettenis <mark.kettenis@xs4all.nl>
Cc: Mark Kettenis <mark.kettenis@xs4all.nl>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463649283-28698-1-git-send-email-ville.syrjala@linux.intel.comAcked-by: NJani Nikula <jani.nikula@intel.com>

Mostly little optimisations and future-proofing against code breakage.
For instance, if the driver is correctly following the submission
protocol, the "out of space" condition is impossible, so the previous
runtime WARN_ON() is promoted to a GEM_BUG_ON() for a more dramatic
effect in development and less impact in end-user systems.

Similarly we can make alignment checking more stringent and replace
other WARN_ON() conditions that don't relate to the runtime hardware
state with either BUILD_BUG_ON() for compile-time-detectable issues, or
GEM_BUG_ON() for logical "can't happen" errors.

With those changes, we can convert it to void, as suggested by Chris
Wilson, and update the calling code appropriately.

v2:
    Note that we're now putting the request seqno in the "fence_id"
    field of each GuC-work-item, in case it turns up somewhere useful
    (e.g. in a GuC log) [Tvrtko Ursulin].
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Rather than wait to see whether more space becomes available in the GuC
submission workqueue, we can just return -EAGAIN and let the caller try
again in a little while. This gets rid of an uninterruptable sleep in
the polling code :)

We'll also add a counter to the GuC client statistics, to see how often
we find the WQ full.

v2:
    Flag the likely() code path (Tvtrko Ursulin).

v4:
    Add/update comments about failure counters (Tvtrko Ursulin).
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The knowledge of how to derive the relevant client from the request
should be localised within i915_guc_submission.c; the LRC code shouldn't
have to know about the internal details of the GuC submission process.
And all the information the GuC code needs should be encapsulated in (or
reachable from) the request.

v2:
    GEM_BUG_ON() for bad GuC client (Tvrtko Ursulin).
    Add/update kerneldoc explaining check_space/submit protocol
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

Split the function of "enable_guc_submission" into two separate
options.  The new one ("enable_guc_loading") controls only the
*fetching and loading* of the GuC firmware image. The existing
one is redefined to control only the *use* of the GuC for batch
submission once the firmware is loaded.

In addition, the degree of control has been refined from a simple
bool to an integer key, allowing several options:
-1 (default)     whatever the platform default is
 0  DISABLE      don't load/use the GuC
 1  BEST EFFORT  try to load/use the GuC, fallback if not available
 2  REQUIRE      must load/use the GuC, else leave the GPU wedged

The new platform default (as coded here) will be to attempt to
load the GuC iff the device has a GuC that requires firmware,
but not yet to use it for submission. A later patch will change
to enable it if appropriate.

v4:
    Changed some error-message levels, mostly ERROR->INFO, per
    review comments by Tvrtko Ursulin.

v5:
    Dropped one more error message, disabled GuC submission on
    hypothetical firmware-free devices [Tvrtko Ursulin].

v6:
    Logging tidy by Tvrtko Ursulin:
     * Do not log falling back to execlists when wedging the GPU.
     * Do not log fw load errors when load was disabled by user.
     * Pass down some error code from fw load for log message to
       make more sense.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v5)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Tested-by: NFiedorowicz, Lukasz <lukasz.fiedorowicz@intel.com>
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v5)
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com> (v6)

For now, anything with a GuC requires uCode loading, and then supports
command submission once loaded. But these are logically distinct from
simply "having a GuC", so we need a separate macro for the latter. Then,
various tests should use this new macro rather than HAS_GUC_UCODE() or
testing enable_guc_submission.

v4:
    Added a couple more uses of the new macro.
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

The GuC initialisation code could do other things apart from loading
firmware, so here we rename the three primary entry points to remove any
specific reference to "ucode" (no functional changes, just renaming).
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>

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

Avoiding the out-of-line call to sg_next() reduces the kernel execution
overhead by 10% in some workloads (for example the Unreal Engine 4 demo
Atlantis on 2GiB GTTs) which are dominated by the cost of inserting PTEs
due to texture thrashing. We can demonstrate this in a microbenchmark
that forces us to rebind the object on every execbuf, where we can
measure a 25% improvement, in the time required to execute an execbuf
requiring a texture to be rebound, for inlining the sg_next() for large
texture sizes.

Benchmark: igt/benchmarks/gem_exec_fault
Benchmark: igt/benchmarks/gem_exec_trace/Atlantis
Signed-off-by: NDave Gordon <david.s.gordon@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: http://patchwork.freedesktop.org/patch/msgid/1463741647-15666-5-git-send-email-chris@chris-wilson.co.uk

The existing for_each_sg_page() iterator is somewhat heavyweight, and is
limiting i915 driver performance in a few benchmarks. So here we
introduce somewhat lighter weight iterators, primarily for use with GEM
objects or other case where we need only deal with whole aligned pages.

Unlike the old iterator, the new iterators use an internal state
structure which is not intended to be accessed by the caller; instead
each takes as a parameter an output variable which is set before each
iteration. This makes them particularly simple to use :)

One of the new iterators provides the caller with the DMA address of
each page in turn; the other provides the 'struct page' pointer required
by many memory management operations.

Various uses of for_each_sg_page() are then converted to the new macros.

v2: Force inlining of the sg_iter constructor and make the union
anonymous.
Signed-off-by: NDave Gordon <david.s.gordon@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: http://patchwork.freedesktop.org/patch/msgid/1463741647-15666-4-git-send-email-chris@chris-wilson.co.uk

We're using this function for ringbuffers and other "small" objects, so
it's worth avoiding an extra malloc()/free() cycle if the page array is
small enough to put on the stack. Here we've chosen an arbitrary cutoff
of 32 (4k) pages, which is big enough for a ringbuffer (4 pages) or a
context image (currently up to 22 pages).

v5:
    change name of local array [Chris Wilson]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-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: http://patchwork.freedesktop.org/patch/msgid/1463741647-15666-3-git-send-email-chris@chris-wilson.co.uk

The recently-added i915_gem_object_pin_map() can be further optimised
for "small" objects. To facilitate this, and simplify the error paths
before adding the new code, this patch pulls out the "mapping" part of
the operation (involving local allocations which must be undone before
return) into its own subfunction.

The next patch will then insert the new optimisation into the middle of
the now-separated subfunction.

This reorganisation will probably not affect the generated code, as the
compiler will most likely inline it anyway, but it makes the logical
structure a bit clearer and easier to modify.

v2:
    Restructure loop-over-pages & error check [Chris Wilson]

v3:
    Add page count to debug messages [Chris Wilson]
    Convert WARN_ON() to GEM_BUG_ON()

v4:
    Drop the DEBUG messages [Tvrtko Ursulin]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-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: http://patchwork.freedesktop.org/patch/msgid/1463741647-15666-2-git-send-email-chris@chris-wilson.co.uk

Found this while browsing Bspec. Looks like it applies to both skl and
kbl.

v2: Also for bxt (Art).

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Cc: "Runyan, Arthur J" <arthur.j.runyan@intel.com>
Reviewed-by: Sonika Jindal<sonika.jindal@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463642060-30728-1-git-send-email-daniel.vetter@ffwll.ch

I just wanted to get rid of the rmw cycle for gen9, but this also
fixes some bugs we haven't carried over, like using recommended
precharge and timeout values.

Also I noticed that we don't set the fastwake sync length on skl, and
that's used by PSR2 selective updates. Fix that.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463590036-17824-6-git-send-email-daniel.vetter@ffwll.ch

On bdw/hsw we have a separate psr dp aux registers to set up, but on
bdw it's shared with the main dp aux thing. Which means any subsequent
dp aux transaction will trample over it, and hence must be done
beforehand.

Also this means we can't do any dp aux transactions while PSR is
active, or at least we must restore the old state.

Probably need a psr disable/enable pair around dp aux transactions in
general.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Sonika Jindal <sonika.jindal@intel.com>
Cc: Durgadoss R <durgadoss.r@intel.com>
Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463590036-17824-5-git-send-email-daniel.vetter@ffwll.ch