As a preparation for follow-up patches add a new helper that checks
whether we hold an RPM reference, since this is what we want most of
the cases. Atm this helper will only check for the HW suspended state, a
follow-up patch will do the actual change to check the refcount instead.
One exception is the forcewake release timer function, where it's
guaranteed that the HW is on even though the RPM refcount drops to zero.
This guarantee is provided by flushing the timer in the runtime suspend
handler. So leave the assert_device_not_suspended check in place there.

Also rename assert_device_suspended for consistency and export these
helpers as a preparation for the follow-up patches.

No functional change.

v3:
- change the assert warning message to be more meaningful (Chris)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1450203038-5150-6-git-send-email-imre.deak@intel.com

We don't really need to check this flag in the get/put/assert helpers,
as on platforms without RPM support we won't ever enable RPM. That means
pm.suspend will be always false and the assert will be always true.

Do this to simplify the code and to let us extend the RPM asserts to all
platforms for a better coverage.

Motivated by Ville.

v2-v3:
- unchanged
v4:
- remove the HAS_RUNTIME_PM check from intel_runtime_pm_enable() too
  made possible by the previous two patches
v5:
- rebased on the previous new patch in the series that keeps
  HAS_RUNTIME_PM() in intel_runtime_pm_enable() with a permanent
  reference taken there
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v3)
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1450352931-16498-1-git-send-email-imre.deak@intel.com

The cherryview device shares many characteristics with the valleyview
device.  When support was added to the driver for cherryview, the
corresponding device info structure included .is_valleyview = 1.
This is not correct and leads to some confusion.

This patch changes .is_valleyview to .is_cherryview in the cherryview
device info structure and simplifies the IS_CHERRYVIEW macro.
Then where appropriate, instances of IS_VALLEYVIEW are replaced with
IS_VALLEYVIEW || IS_CHERRYVIEW or equivalent.

v2: Use IS_VALLEYVIEW || IS_CHERRYVIEW instead of defining a new macro.
    Also add followup patches to fix issues discovered during the first
    review. (Ville)
v3: Fix some style issues and one gen check. Remove CRT related changes
    as CRT is not supported on CHV. (Imre, Ville)
v4: Make a few more optimizations. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NWayne Boyer <wayne.boyer@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1449692975-14803-1-git-send-email-wayne.boyer@intel.comReviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: NJani Nikula <jani.nikula@intel.com>

Make I915_READ and I915_WRITE more type safe by wrapping the register
offset in a struct. This should eliminate most of the fumbles we've had
with misplaced parens.

This only takes care of normal mmio registers. We could extend the idea
to other register types and define each with its own struct. That way
you wouldn't be able to accidentally pass the wrong thing to a specific
register access function.

The gpio_reg setup is probably the ugliest thing left. But I figure I'd
just leave it for now, and wait for some divine inspiration to strike
before making it nice.

As for the generated code, it's actually a bit better sometimes. Eg.
looking at i915_irq_handler(), we can see the following change:
  lea    0x70024(%rdx,%rax,1),%r9d
  mov    $0x1,%edx
- movslq %r9d,%r9
- mov    %r9,%rsi
- mov    %r9,-0x58(%rbp)
- callq  *0xd8(%rbx)
+ mov    %r9d,%esi
+ mov    %r9d,-0x48(%rbp)
 callq  *0xd8(%rbx)

So previously gcc thought the register offset might be signed and
decided to sign extend it, just in case. The rest appears to be
mostly just minor shuffling of instructions.

v2: i915_mmio_reg_{offset,equal,valid}() helpers added
    s/_REG/_MMIO/ in the register defines
    mo more switch statements left to worry about
    ring_emit stuff got sorted in a prep patch
    cmd parser, lrc context and w/a batch buildup also in prep patch
    vgpu stuff cleaned up and moved to a prep patch
    all other unrelated changes split out
v3: Rebased due to BXT DSI/BLC, MOCS, etc.
v4: Rebased due to churn, s/i915_mmio_reg_t/i915_reg_t/
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1447853606-2751-1-git-send-email-ville.syrjala@linux.intel.com

Add 'u32 offset' to the uncore register access functions. For now
it's the same as 'reg', but once type safety gets added 'reg' will be
the type safe register variable and 'offset' the raw offset.

v2: s/uint32_t/u32/ (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446839236-20035-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

I need to add a new variable into GEN6_{READ,WRITE}_HEADER, but the vgpu
won't need it, so let's avoid an unused variable warning by splitting
the vgpu stuff to use its own macros.

Cc: Eddie Dong <eddie.dong@intel.com>
Cc: Jike Song <jike.song@intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Yu Zhang <yu.c.zhang@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Zhiyuan Lv <zhiyuan.lv@intel.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446672017-24497-26-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NZhiyuan Lv <zhiyuan.lv@intel.com>

Store the upper dword of the register offset in the whitelist as well.
This would allow it to read register where the two halves aren't sitting
right next to each other, and it'll make it easier to make register
access type safe.

While at it change the register offsets to u32 from u64. Our register
space isn't quite that big, yet :)

v2: Use ldw/udw as the suffixes, and add a note about
    64bit wide split regs (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446839021-18599-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

We have a timed release of a forcewake when using
I915_READ/WRITE macros. wait_for() macro will go to quite
long sleep if the first read doesn't satisfy the condition for
successful exit. With these two interacting, it is possible that
we lose the forcewake during the wait_for() and the subsequent read
will reaquire forcewake.

Further experiments with skl shows that when we lose forcewake,
we lose the reset request we submitted. So reset request register
is not power context saved.

Grab forcewakes for all engines before starting the reset/request
dance so that all requests stay valid for the duration of reset
requisition across all the engines.

v2: Add comment on power well sleeps. Wrap the reset handling
    under forcewake instead of just reset requests (Chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92774
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: Tomi Sarvela <tomix.p.sarvela@intel.com> (v1, v2)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446721898-1450-1-git-send-email-mika.kuoppala@intel.comSigned-off-by: NJani Nikula <jani.nikula@intel.com>

Include an early NEEDS_FORCEWAKE() check for vlv and chv.
Hopefully that will avoid doing so many range checks in for many
register accesses (at least for all display registers).

Note that vlv already had the check in the write path since it shares
the gen6+ code for that.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445517300-28173-6-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Change the fw domain handling in the vlv/chv register read/write
functions to look more like the SKL code, ie. have a single
__force_wake_get() get call instead of multiple ones.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445517300-28173-5-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445517300-28173-4-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Change FORCEWAKE & co. reads for the error state to use I915_READ_FW().
Reading a FORCEWAKE register using a function that can frob forcewake
just seems wrong.

There is a check to skip grabbing the forcewake for accessing FORCEWAKE
in intel_uncore.c, but there's no such check for FORCEWAKE_MT. So no
idea what is currently happening with FORCEWAKE_MT reads. FORCEWAKE_VLV
is fortunately outside the forcewake range anyway, so no actual issue
with that one.

So let's just make the rule that you can't access FORCEWAKE registers with
the normal I915_READ() stuff, and we can drop the extra FORCEWAKE check
from NEEDS_FORCEWAKE(). While at it use NEEDS_FORCEWAKE() on BDW, where
it was skipped for whatever bikeshed reason that I've already forgotten.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445517300-28173-3-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

There's no need for __raw_i915_read8() & co. to be macros, so make them
inline functions. To avoid typo mistakes generate the inline functions
using preprocessor templates.

We have a few users of the raw register acces functions outside
intel_uncore.c, so let's also move the functions into intel_drv.h.

While doing that switch I915_READ_FW() & co. to use the
__raw_i915_read() functions, and use the _FW macros everywhere
outside intel_uncore.c where we want to read registers without
grabbing forcewake and whatnot. The only exception is
i915_check_vgpu() which itself gets called from intel_uncore.c,
so using the __raw_i915_read stuff there seems appropriate.

v2: Squash in the intel_uncore.c->i915_drv.h move
    Convert I915_READ_FW() to use __raw_i915_read(), and use
    I915_READ_FW() outside of intel_uncore.c (Chris)
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445517300-28173-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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>

On BXT, We Observe timeout for forcewake request completion with 2ms polling period as given here:
[drm:fw_domains_get] ERROR render: timed out waiting for forcewake ack request.
Polling for 50ms is recommended to avoid these timeouts.

Change-Id: Ie715b0069a3049606e9602bc5e97a6511890864d
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed by: Alex Dai <yu.dai@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Unless future specs tells otherwise we can assume future gens
inherit some stuff from the previous so let's handle
missed cases when we know tehy should't be there and assume
default equals newest one.

No functional changes.

v2: Remove useless case as pointed out by Ville.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Dear git bisect user,

Even though this is the patch that introduced the WARN() you're
bisecting, please notice that it's very likely that the problem you're
facing was already present before this commit. In other words: this
commit adds code to detect errors and give WARN()s about them, but the
errors were already there.

In order to continue your debug, please use the i915.mmio_debug
option, check the backtraces and try to discover which read or write
operation is causing the error message. Then check if this is
happening because the register does not exist or because its power
well is down when the operation is being done.

On my SKL machine, if I use i915.mmio_debug=999, this patch triggers
42 WARNs just by booting. I didn't investigate them yet. Normal users
are only going to get a single WARN due to the default i915.mmio_debug
setting.

Thank you for your comprehension,
Paulo
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

A couple of hand rolled ARRAY_SIZE()s caught my eye. Get rid of them.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since the hardware sometimes mysteriously totally flummoxes the 64bit
read of a 64bit register when read using a single instruction, split the
read into two instructions. Since the read here is of automatically
incrementing timestamp counters, we also have to be very careful in
order to make sure that it does not increment between the two
instructions.

However, since userspace tried to workaround this issue and so enshrined
this ABI for a broken hardware read and in the process neglected that
the read only fails in some environments, we have to introduce a new
uABI flag for userspace to request the 2x32 bit accurate read of the
timestamp.

v2: Fix alignment check and include details of the workaround for
userspace.
Reported-by: NKarol Herbst <freedesktop@karolherbst.de>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91317
Testcase: igt/gem_reg_read
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: stable@vger.kernel.org
Tested-by: NMichał Winiarski <michal.winiarski@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If the user disables the GPU reset using the i915.reset parameter and
one occurs, report that we failed to reset the GPU. If we return early,
as we currently do, then we leave all state intact (with a hung GPU)
and clients block forever waiting for their requests to complete.

Testcase: igt/gem_eio
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Mark i915.reset as an unsafe modoption, as discussed with
Chris.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In order for gen8+ hardware to guarantee that no context switch
takes place during engine reset and that current context is properly
saved, the driver needs to notify and query hw before commencing
with reset.

There are gpu hangs where the engine gets so stuck that it never will
report to be ready for reset. We could proceed with reset anyway, but
with some hangs with skl, the forced gpu reset will result in a system
hang. By inspecting the unreadiness for reset seems to correlate with
the probable system hang.

We will only proceed with reset if all engines report that they
are ready for reset. If root cause for system hang is found and
can be worked around with another means, we can reconsider if
we can reinstate full reset for unreadiness case.

v2: -EIO, Recovery, gen8 (Chris, Tomas, Daniel)
v3: updated commit msg
v4: timeout_ms, simpler error path (Chris)

References: https://bugs.freedesktop.org/show_bug.cgi?id=89959
References: https://bugs.freedesktop.org/show_bug.cgi?id=90854
Testcase: igt/gem_concurrent_blit/prw-blt-overwrite-source-read-rcs-forked
Testcase: igt/gem_concurrent_blit/gtt-blt-overwrite-source-read-rcs-forked
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tomas Elf <tomas.elf@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
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>

This WA is avoid problem between shadow vs wake FIFO unload
problem during CPD/RC6 transactions on CHV.

v2: Define individual bits GTFIFOCTL (Ville)

v3: move WA to uncore_early_sanitize (ville)
Signed-off-by: NDeepak S <deepak.s@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
[Jani: fixed some whitespace issues while applying]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

This eliminates six needless spin lock/unlock pairs when writing out
ELSP.

v2: Respin with my preferred colour.
v3: Mostly back to the original colour

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> [v1]
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>

If we have a single unclaimed register, we will have lots. A WARN for
each one makes the machine unusable and does not aid debugging. Convert
the i915.mmio_debug option to a counter for how many WARNs to fire
before shutting up. Even when i915.mmio_debug was disabled it would
continue to shout an *ERROR* for every interrupt, without any
information at all for debugging.

The massive verbiage was added in
commit 5978118c
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Wed Jul 16 17:49:29 2014 -0300

    drm/i915: reorganize the unclaimed register detection code

v2: Automatically enable invalid mmio reporting for the *next* invalid
access if mmio_debug is disabled by default. This should give us clearer
debug information without polluting the logs too much.
v3: Compile fixes, rebase.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Update modparam text per the thread.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit 05a2fb15 ("drm/i915: Consolidate forcewake code")
failed to take into account that we have used to reset both
the gen6 style and the multithreaded style forcewake registers.
This is due to fact that ivb can use either, depending on how the
bios has set up the machine.

Mimic the old semantics before we have determined the correct variety
and reset both before the ecobus probe.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit 05a2fb15 ("drm/i915: Consolidate forcewake code")
failed to take into account that we have used to reset both
the gen6 style and the multithreaded style forcewake registers.
This is due to fact that ivb can use either, depending on how the
bios has set up the machine.

Mimic the old semantics before we have determined the correct variety
and reset both before the ecobus probe.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

When querying the GTFIFOCTL register to check the FIFO space, the read value
must be masked. The operation is repeated explicitly in several places. This
change refactors the read-and-mask code into a function call.

v2: rebased on top of Mika's forcewake patch set, specifically:
	[PATCH 8/8] drm/i915: Enum forcewake domains and domain identifiers

Change-Id: Id1a9f3785cb20b82d4caa330c37b31e4e384a3ef
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NNick Hoath <nicholas.hoath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Suggested-by: NDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At the moment we compare the whole EDRAM_PRESENT/EDRAMCAP register value
to 1 while EDRAM_PRESENT is only bit 0 (the rest may be used to describe
eDRAM capabilities).

To be more future proof, only look at bit 0 to detect eDRAM presence.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the virtualized environment, forcewake operations are not
necessary for the driver, because mmio accesses will be trapped
and emulated by the host side, and real forcewake operations are
also done in the host. New mmio access handlers are added to directly
call the __raw_i915_read/write, therefore will reduce many traps and
increase the overall performance for drivers running in the VM with
Intel GVT-g enhancement.

v2:
take Chris' comments:
        - register the mmio hooks in intel_uncore_init()
v3:
take Daniel's comments:
        - use macros to assign mmio write functions for vGPU
v4:
take Tvrtko's comments:
        - also use mmio hooks for read operations
Signed-off-by: NYu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>k
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Introduce a PV INFO structure, to facilitate the Intel GVT-g
technology, which is a GPU virtualization solution with mediated
pass-through. This page contains the shared information between
i915 driver and the host emulator. For now, this structure utilizes
an area of 4K bytes on HSW GPU's unused MMIO space. Future hardware
will have the reserved window architecturally defined, and layout
of the page will be added in future BSpec.

The i915 driver load routine detects if it is running in a VM by
reading the contents of this PV INFO page. Thereafter a flag,
vgpu.active is set, and intel_vgpu_active() is used by checking
this flag to conclude if GPU is virtualized with Intel GVT-g. By
now, intel_vgpu_active() will return true, only when the driver
is running as a guest in the Intel GVT-g enhanced environment on
HSW platform.

v2:
take Chris' comments:
        - call the i915_check_vgpu() in intel_uncore_init()
        - sanitize i915_check_vgpu() by adding BUILD_BUG_ON() and debug info
take Daniel's comments:
        - put the definition of PV INFO into a new header - i915_vgt_if.h
other changes:
        - access mmio regs by readq/readw in i915_check_vgpu()

v3:
take Daniel's comments:
        - move the i915/vgt interfaces into a new i915_vgpu.c
        - update makefile
        - add kerneldoc to functions which are non-static
        - add a DOC: section describing some of the high-level design
        - update drm docbook
other changes:
        - rename i915_vgt_if.h to i915_vgpu.h

v4:
take Tvrtko's comments:
        - fix a typo in commit message
        - add debug message when vgt version mismatches
        - rename low_gmadr/high_gmadr to mappable/non-mappable in PV INFO
          structure
Signed-off-by: NYu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Signed-off-by: NEddie Dong <eddie.dong@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We added this WARN_ON to guard against using uninitialized
forcewake domains. But forgot blissfully that not all
gens have forcewake domains in the first place.

v2: Move WARN_ON to fw_domains_init (Chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88911
Tested-by: Ding Heng <hengx.ding@intel.com> (v1)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[Jani: add comment above WARN_ON as suggested by Chris]
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The checking for ack and also any subsequent mmio access
will serialize with setting the forcewake bit. Drop the
posting read as superfluous.

Note that in the put side we still want to keep the posting read
as it will ensure that the hw sees our forcewake release in a
timely manner and doesn't keep the hw powered up.

Comment from Chris:

On Wed, Jan 28, 2015 at 05:54:14PM +0200, Mika Kuoppala wrote:
> Ville Syrjälä <ville.syrjala@linux.intel.com> writes:
> > IIRC the posting read from same cache line actually fixed real bugs. So
> > I'm a bit worried about dropping them. But I suppose it's possible only
> > the _put side was important for those bugs.
>
> I found these:
>
> commit 6af2d180
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Thu Jul 26 16:24:50 2012 +0200
>
>     drm/i915: fix forcewake related hangs on snb
>
> commit 8dee3eea
> Author: Ben Widawsky <ben@bwidawsk.net>
> Date:   Sat Sep 1 22:59:50 2012 -0700
>
>     drm/i915: Never read FORCEWAKE
>
> https://bugs.freedesktop.org/show_bug.cgi?id=51738
> https://bugs.freedesktop.org/show_bug.cgi?id=52424
>
> The snb here seems to survive gem_dummy_reloc_loop and
> gem_ring_sync_loop in here with the get side posting removed.

Note that we kept the once associated with #52424, but judging by my
comments in #51738 the posting read is just a band aid anyway as a full
mb() itself was not adequate.
Suggested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: paste relevant review discussion in.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_uncore_early_sanitize() will reset the forcewake registers. When
forcewake domains were introduced, the domain init was done after the
sanitization of the forcewake registers. And as the resetting of
registers use the domain accessors, we tried to reset the forcewake
registers with unitialized forcewake domains and failed.

Fix this by sanitizing after all the domains have been initialized. Do
per domain clearing of forcewake register on domain init so that
IVB can do early access to ECOBUS do determine the final configuration.

This regression was introduced in

commit 05a2fb15
Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date:   Mon Jan 19 16:20:43 2015 +0200

    drm/i915: Consolidate forcewake code

v2: Carve out ellc detect, fw_domain_reset for ivb/ecobus (Chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88805
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: NOlof Johansson <olof@lixom.net>
Tested-by: Darren Hart <dvhart@linux.intel.com> (v1)
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make the domains and domain identifiers enums. To emphasize
the difference in order to avoid mistakes.

v2: s/fw_domain/forcewake_domain (Jani)
v3: rebase
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have multiple forcewake domains now on recent gens. Change the
function naming to reflect this.

v2: More verbose names (Chris)
v3: Rebase
v4: Rebase
v5: Add documentation for forcewake_get/put
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com> (v2)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These two were using a fw dance logic where posting read was done
after both domain bit were set. When in other gens, the posting
read is done immediately after setting the forcewake bit for each
domain.

Now bring these in line with other gens.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NDeepak S <deepak.s@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>