As with processes which run on the CPU, the goal of multiple VMs is to
provide process isolation. Specific to GEN, there is also the ability to
map more objects per process (2GB each instead of 2Gb-2k total).

For the most part, all the pipes have been laid, and all we need to do
is remove asserts and actually start changing address spaces with the
context switch. Since prior to this we've converted the setting of the
page tables to a streamed version, this is quite easy.

One important thing to point out (since it'd been hotly contested) is
that with this patch, every context created will have it's own address
space (provided the HW can do it).

v2: Disable BDW on rebase

NOTE: I tried to make this commit as small as possible. I needed one
place where I could "turn everything on" and that is here. It could be
split into finer commits, but I didn't really see much point.

Cc: Eric Anholt <eric@anholt.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We call intel_modeset_setup_hw_state() along two paths, driver
load/resume and after a lid event notification. During initialisation of
the driver, it is imperative that we reset the config state. This
correctly sets up the initial connector statuses and prepares the
hardware for a thorough probing. However, during a lid event, we only
want to undo the damage caused by the bios by resetting our last known
mode. In this cirumstance, we do not want to clobber our desired state.

In order to try and keep sanity between the config state and our own
tracking, do the drm_mode_config_reset() first along the load/resume
paths before reading out the hw state and apply any definite known
corrections.

v2: "As discussed on irc I don't think we should force the connector
state to anything here: Imo connector->status should reflect what we
believe to be the true output connection state, whereas connector->encoder
reflects whether this connector is wired up to a pipe. And since we no
longer reject modeset on disconnected connectors and never nuked the pipe
if the connector gets disconnected there's no reason for that - such policy
is userspace's job.

This regression has been introduced in

commit 2e938892
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 11 20:08:24 2012 +0200

    drm/i915/crt: explicitly set up HOTPLUG_BITS on resume"
so sayeth Daniel.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: stable@vger.kernel.org (v3.8 and later)
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is just a theoretical issue, but we need to do this to prevent the
WARN in pipe_from_connector at suspend time.

This regression has been introduce in

commit 7bd688cd
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Fri Nov 8 16:48:56 2013 +0200

    drm/i915: handle backlight through chip specific functions

https://bugs.freedesktop.org/show_bug.cgi?id=71978Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This would have never worked.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Oops, makes testing early boot failures in i915.ko a bit more pain, so
let's fix it.

v2: We already have a bit of static storage to track this (Chris).
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

At least since SNB (perhaps even earlier) even the desktop parts
should have FBC.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's been 5 years since kms support was merged and roughly 4 years
since UMS support was ripped out from userspace drivers.

Thus far it's not been a big burden to keep the ums paths alive, and
we've made some good progress in better separating it from the kms
code by sprinkling DRIVER_MODESET checks all over the place.

But now that the drm demidlayering is within reach this changes. I
want to make the driver loading code more robust using devres.c and
other cool tricks. But that doesn't work with ums due to the
shadow-attach trick. Which means we either
a) need to split out a complete ums codebase like radeon has
b) kill it for good.

The 2nd option is obviously much less work than the first, so I think
it's time to test the waters and see how many people out there still
use ums.

I've decided that silently failing to initialize the driver (and not
e.g. failing to load the module) is the right thing. That way we
should only get reports from users that actually care about some ums
features (like accelerated gl or support for secondary outputs).
Everyone else will just fall back to the vesa X driver.

For developers there's a small info level dmesg output.

The plan is to drop this Kconfig option after 3.16 (so gives us 2 full
releases) and then start killing code for real 2-3 releases
afterwards. That should be more than enough time for users to pipe up.

Of course if anyone does we need to revisit this plan and maybe go
with option a) above.

Also enable the KMS support by default in Kconfig and polish the help
texts a bit.

v2: Add the missing hunk of actual code changes. Oops. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Thus far we've tried to carefully work around the fact that old
userspace relied on the AGP-backed legacy buffer mapping ioctls for a
bit too long. But it's really horribly, and now some new users for it
started to show up again:

http://www.mail-archive.com/mesa-dev@lists.freedesktop.org/msg45547.html

This uses drmAgpSize to figure out the GTT size, which is both the
wrong thing to inquire and also might force us to keep this crap
around for another few years.

So I want to stop this particular zombie from raising ever again. Now
it's only been 4 years since XvMC was fixed for gen3, so a bit early
by the usual rules. But since Linus explicitly said that an ABI
breakage only counts if someone actually observes it I want to tempt
fate an accelarate the demise of AGP.

We probably need to wait 2-3 kernel releases with this shipping until
we go on a killing spree code-wise.

v2: Remove intel_agp_enabled since it's unused (Ville).

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Acked-by: NDave Airlie <airlied@gmail.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Most platforms din't hit this condition, but if we want to allow
building without agp we should also make this allowed on gen3.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We don't want any ERROR for simulated gpu hangs, otoh printing the
error code when the reset failed for real should be interesting.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71333
lu hua <huax.lu@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We only depend on the intel-gtt module for GTT frobbign on older gens.
The intel_agp module is optional, except for UMS and some old XvMC
userland on gen3. So make AGP support optional. As before, we will
fail the i915 init for UMS and gen3 KMS the same as before if
intel_agp isn't around.

intel-gtt.c is left with a somewhat ugly ifdef mess, but I'm going
to save that for a later cleaning.

At least my gen2 still works with the patch and CONFIG_AGP=n.

v2: Make i915 depend on X86 and PCI, and intel-gtt depend on PCI
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Early platforms use the same PCH as HSW, and to avoid triggering the
!ULT, and !HSW warnings, simply put it first in the search.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We've done insufficient testing on them thus far, so keep them disabled
until we do test.

v2: Use WARN when not enabling preliminary HW support as this should
only be disabled for that case.

v3: Rip out the now useless (and really noisy) DRM_INFO output.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuosugeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The platforms we currently have all have LPT LP on them. As such, we
have no way to identify the new WPT PCH that will ship with Broadwell.

NOTE: For all purposes relevant to the driver that this point, LPT and
WPT are equivalent. Therefore there should be no need to actually change
this for some time.

v2: Don't assign dev_priv->num_pch_pll any more.

v3: Rebase on top of the PCH detection changes for virtualized
enviroments.

v4: Wrote commit message

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v3)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Rebase (Paulo Zanoni)

v3: Rebase on top of num_pipes having moved to intel_device_info.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> (v1)
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v2)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Squash in "drm/i915/bdw: Add BDW to the HAS_DDI check" as
suggested by Damien.

v3: Squash in VEBOX enabling from  Zhao Yakui <yakui.zhao@intel.com>

v4: Rebase on top of Jesse's patch to extract all pci ids to
include/drm/i915_pciids.h.

v4: Replace Halo by its marketing moniker Iris. Requested by Ben.

v5: Switch from info->has*ring to info->ring_mask.

v6: Add 0x16X2 variant (which is newer than this patch)
Rename to use new naming scheme (Chris)
Remove Simulator PCI ids. These snuck in during rebase (Chris)

v7: Fix poor sed job from v6
Make the desktop variants use the desktop macro (Rebase error). Notice
that this makes no functional difference - it's just confusing.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

v2: Fixed the botched locking on init_hw failure in i915_reset (Ville)
Call cleanup_ringbuffer on failed context create in init_hw (Ville)

v3: Add dev argument ti clean_ringbuffer
Reviewed-by: NKenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Similarly rename the other related functions in the power domain
interface.

Higher level driver code calling these functions knows only about power
domains, not the underlying power wells which may be different on
different platforms. Also these functions really init/cleanup/resume
power domains and only through that all related power wells, so rename
them accordingly.

Note that I left i915_{request,release}_power_well as is, since that
really changes the state only of a single power well (and is HSW
specific). It should also get a better name once we make it more
generic by controlling things through a new audio power domain.

v4:
- use intel prefix instead of i915 everywhere (Paulo)
- use a $prefix_$block_$action format (Daniel)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Currently we make sure that all power domains are enabled during driver
init and turn off unneded ones only after the first modeset. Similarly
during suspend we enable all power domains, which will remain on through
the following resume until the first modeset.

This logic is supported by intel_set_power_well() in the power domain
framework. It would be nice to simplify the API, so that we only have
get/put functions and make it more explicit on the higher level how this
"power well on during init" logic works. This will make it also easier
if in the future we want to shorten the time the power wells are on.

For this add a new device private flag tracking whether we have the
power wells on because of init/suspend and use only
intel_display_power_get()/put(). As nothing else uses
intel_set_power_well() we can remove it.

This also fixes

commit 6efdf354
Author: Imre Deak <imre.deak@intel.com>
Date:   Wed Oct 16 17:25:52 2013 +0300

    drm/i915: enable only the needed power domains during modeset

where removing intel_set_power_well() resulted in not releasing the
reference on the power well that was taken during init and thus leaving
the power well on all the time. Regression reported by Paulo.

v2:
- move the init_power_on flag to the power_domains struct (Daniel)

v3:
- add note about this being a regression fix too (Paulo)
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Once the machine gets to a certain point in the suspend process, we
expect the GPU to be idle. If it is not, we might corrupt memory.
Empirically (with an early version of this patch) we have seen this is
not the case. We cannot currently explain why the latent GPU writes
occur.

In the technical sense, this patch is a workaround in that we have an
issue we can't explain, and the patch indirectly solves the issue.
However, it's really better than a workaround because we understand why
it works, and it really should be a safe thing to do in all cases.

The noticeable effect other than the debug messages would be an increase
in the suspend time. I have not measure how expensive it actually is.

I think it would be good to spend further time to root cause why we're
seeing these latent writes, but it shouldn't preclude preventing the
fallout.

NOTE: It should be safe (and makes some sense IMO) to also keep the
VALID bit unset on resume when we clear_range(). I've opted not to do
this as properly clearing those bits at some later point would be extra
work.

v2: Fix bugzilla link

Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=65496
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=59321Tested-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Tested-By: NTodd Previte <tprevite@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have two once very similar functions, i915_gpu_idle() and
i915_gem_idle(). The former is used as the lower level operation to
flush work on the GPU, whereas the latter is the high level interface to
flush the GEM bookkeeping in addition to flushing the GPU. As such
i915_gem_idle() also clears out the request and activity lists and
cancels the delayed work. This is what we need for unloading the driver,
unfortunately we called i915_gpu_idle() instead.

In the process, make sure that when cancelling the delayed work and
timer, which is synchronous, that we do not hold any locks to prevent a
deadlock if the work item is already waiting upon the mutex. This
requires us to push the mutex down from the caller to i915_gem_idle().

v2: s/i915_gem_idle/i915_gem_suspend/

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70334Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: xunx.fang@intel.com
[danvet: Only set ums.suspended for !kms as discussed earlier. Chris
noticed that this slipped through.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've sent this patch several times for various reasons. It essentially
cleans up a lot of code where we need to do something per ring, and want
to query whether or not the ring exists on that hardware.

It has various uses coming up, but for now it shouldn't be too
offensive.

v2: Big conflict resolution on Damien's DEV_INFO_FOR_EACH stuff

v3: Resolved vebox addition

v4: Rebased after months of disuse. Also made failed ringbuffer init
cleaner.

v5: Remove the init cleaner from v4. There is a better way to do it.
(Chris)
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I had this lying around from he original PPGTT series, and thought we
might try to get it in by itself.

It's convenient to just call i915_gem_init_hw at reset because we'll be
adding new things to that function, and having just one function to call
instead of reimplementing it in two places is nice.

In order to accommodate we cleanup ringbuffers in order to bring them
back up cleanly. Optionally, we could also teardown/re initialize the
default context but this was causing some problems on reset which I
wasn't able to fully debug, and is unnecessary with the previous context
init/enable split.

This essentially reverts:
commit 8e88a2bd
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Jun 19 18:40:00 2012 +0200

    drm/i915: don't call modeset_init_hw in i915_reset

It seems to work for me on ILK now. Perhaps it's due to:
commit 8a5c2ae7
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Thu Mar 28 13:57:19 2013 -0700

    drm/i915: fix ILK GPU reset for render
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that MMIO has been split up into gen specific functions it is
obvious when HAS_FPGA_DBG_UNCLAIMED, HAS_FORCE_WAKE are needed. As such,
we can remove this extraneous condition.

As a result of this, as well as previously existing function pointers
for forcewake, we no longer need the has_force_wake member in the device
specific data structure.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

All drivers embed gem-objects into their own buffer objects. There is no
reason to keep drm_gem_object_alloc(), gem->driver_private and
->gem_init_object() anymore.

New drivers are highly encouraged to do the same. There is no benefit in
allocating gem-objects separately.

Cc: Dave Airlie <airlied@gmail.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Ben Skeggs <skeggsb@gmail.com>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Call intel_uncore_early_sanitize() first thing during resume to prevent
stale BIOS leftovers from being reported as unclaimed register access.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

i915_restore_state() -> i915_restore_display() will attempt to
re-disable VGA during resume. So the power well needs to be powered on
before that.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The init and resume codepaths want to handel the power well in slightly
different ways, so pull the power well init out from
intel_modeset_init_hw() which gets called in both cases.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Both callers had code to sanitize the uncore and restore the GTT
mappings just before calling __i915_drm_thaw, so Chris suggested I
should unify the code.
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>

Now when we have mechanism in place to track which context
was guilty of hanging the gpu, it is possible to punish
for bad behaviour.

If context has recently submitted a faulty batchbuffers guilty of
gpu hang and submits another batch which hangs gpu in quick
succession, ban it permanently. If ctx is banned, no more
batchbuffers will be queued for execution.

There is no need for global wedge machinery anymore and
it would be unwise to wedge the whole gpu if we have multiple
hanging batches queued for execution. Instead just ban
the guilty ones and carry on.

v2: Store guilty ban status bool in gpu_error instead of pointers
    that might become danling before hang is declared.

v3: Use return value for banned status instead of stashing state
    into gpu_error (Chris Wilson)

v4: - rebase on top of fixed hang stats api
    - add define for ban period
    - rename commit and improve commit msg

v5: - rely context banning instead of wedging the gpu
    - beautification and fix for ban calculation (Chris)
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>

We still maintain code internally that cares about preliminary support.
Leaving the check here doesn't hurt anyone, and should keep things more
in line.

This time around, stick the info in the intel_info structure, and also
change the error from DRM_ERROR->DRM_INFO.

This is a partial revert of:
commit 590e4df8
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Wed May 8 10:45:15 2013 -0700

    drm/i915: VLV support is no longer preliminary

Daniel, I'll provide the fix ups for internal too if/when you merge
this (if you want).

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For use by userspace (at some point in the future) and other kernel code.

v2: move PCI IDs to uabi (Chris)
    move PCI IDs to drm/ (Dave)
v3: fixup Quanta detection - needs to come first (Daniel)
v4: fix up PCI match structure init for easier use by userspace (Chris)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Enable support for drm render nodes for i915 by flagging the ioctls that
are safe and just needed for rendering.

v2: mark reg_read, set_caching and get_caching (ickle, danvet)
Signed-off-by: NKristian Høgsberg <krh@bitplanet.net>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This should be working, so enable it by default. Also easy to revert.

v2: Rebase, s/allow/enable/.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We currently only enter PC8+ after all its required conditions are
met, there's no rendering, and we stay like that for at least 5
seconds.

I chose "5 seconds" because this value is conservative and won't make
us enter/leave PC8+ thousands of times after the screen is off: some
desktop environments have applications that wake up and do rendering
every 1-3 seconds, even when the screen is off and the machine is
completely idle.

But when I was testing my PC8+ patches I set the default value to
100ms so I could use the bad-behaving desktop environments to
stress-test my patches. I also thought it would be a good idea to ask
our power management team to test different values, but I'm pretty
sure they would ask me for an easy way to change the timeout. So to
help these 2 cases I decided to create an option that would make it
easier to change the default value. I also expect people making
specific products that use our driver could try to find the perfect
timeout for them.

Anyway, fixing the bad-behaving applications will always lead to
better power savings than just changing the timeout value: you need to
stop waking the Kernel, not quickly put it back to sleep again after
you wake it for nothing. Bad sleep leads to bad mood!
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch allows PC8+ states on Haswell. These states can only be
reached when all the display outputs are disabled, and they allow some
more power savings.

The fact that the graphics device is allowing PC8+ doesn't mean that
the machine will actually enter PC8+: all the other devices also need
to allow PC8+.

For now this option is disabled by default. You need i915.allow_pc8=1
if you want it.

This patch adds a big comment inside i915_drv.h explaining how it
works and how it tracks things. Read it.

v2: (this is not really v2, many previous versions were already sent,
     but they had different names)
    - Use the new functions to enable/disable GTIMR and GEN6_PMIMR
    - Rename almost all variables and functions to names suggested by
      Chris
    - More WARNs on the IRQ handling code
    - Also disable PC8 when there's GPU work to do (thanks to Ben for
      the help on this), so apps can run caster
    - Enable PC8 on a delayed work function that is delayed for 5
      seconds. This makes sure we only enable PC8+ if we're really
      idle
    - Make sure we're not in PC8+ when suspending
v3: - WARN if IRQs are disabled on __wait_seqno
    - Replace some DRM_ERRORs with WARNs
    - Fix calls to restore GT and PM interrupts
    - Use intel_mark_busy instead of intel_ring_advance to disable PC8
v4: - Use the force_wake, Luke!
v5: - Remove the "IIR is not zero" WARNs
    - Move the force_wake chunk to its own patch
    - Only restore what's missing from RC6, not everything
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>

When building kernels for a preliminary hardware target, having to add a
kernel command-line option can prove inconvenient.  Add a Kconfig option
that changes the default of this option to 1.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
[danvet: Pimp the Kconfig help text a bit as suggested by Damien in
his 2nd review.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The new arch_phys_wc_add/del functions do the right thing both with
and without MTRR support in the kernel. So we can drop these
additional checks.

David Herrmann suggest to also kill the DRIVER_USE_MTRR flag since
it's now unused, which spurred me to do a bit a better audit of the
affected drivers. David helped a lot in that. Quoting our mail
discussion:

On Wed, Jul 10, 2013 at 5:41 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
> On Wed, Jul 10, 2013 at 5:22 PM, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
>> On Wed, Jul 10, 2013 at 3:51 PM, David Herrmann <dh.herrmann@gmail.com> wrote:
>>>> -#if __OS_HAS_MTRR
>>>> -static inline int drm_core_has_MTRR(struct drm_device *dev)
>>>> -{
>>>> -       return drm_core_check_feature(dev, DRIVER_USE_MTRR);
>>>> -}
>>>> -#else
>>>> -#define drm_core_has_MTRR(dev) (0)
>>>> -#endif
>>>> -
>>>
>>> That was the last user of DRIVER_USE_MTRR (apart from drivers setting
>>> it in .driver_features). Any reason to keep it around?
>>
>> Yeah, I guess we could rip things out. Which will also force me to
>> properly audit drivers for the eventual behaviour change this could
>> entail (in case there's an x86 driver which did not ask for an mtrr,
>> but iirc there isn't).
>
> david@david-mb ~/dev/kernel/linux $ for i in drivers/gpu/drm/* ; do if
> test -d "$i" ; then if ! grep -q USE_MTRR -r $i ; then echo $i ; fi ;
> fi ; done
> drivers/gpu/drm/exynos
> drivers/gpu/drm/gma500
> drivers/gpu/drm/i2c
> drivers/gpu/drm/nouveau
> drivers/gpu/drm/omapdrm
> drivers/gpu/drm/qxl
> drivers/gpu/drm/rcar-du
> drivers/gpu/drm/shmobile
> drivers/gpu/drm/tilcdc
> drivers/gpu/drm/ttm
> drivers/gpu/drm/udl
> drivers/gpu/drm/vmwgfx
> david@david-mb ~/dev/kernel/linux $
>
> So for x86 gma500,nouveau,qxl,udl,vmwgfx don't set DRIVER_USE_MTRR.
> But I cannot tell whether they break if we call arch_phys_wc_add/del,
> anyway. At least nouveau seemed to work here, but it doesn't use AGP
> or drm_bufs, I guess.

Cool, thanks a lot for stitching together the list of drivers to look
at. So for real KMS drivers it's the drives responsibility to add an
mtrr if it needs one. nouvea, radeon, mgag200, i915 and vmwgfx do that
already. Somehow the savage driver also ends up doing that, I have no
idea why.

Note that gma500 as a pure KMS driver doesn't need MTRR setup since
the platforms that it supports all support PAT. So no MTRRs needed to
get wc iomappings.

The mtrr support in the drm core is all for legacy mappings of garts,
framebuffers and registers. All legacy drivers set the USE_MTRR flag,
so we're good there.

All in all I think we can really just ditch this

/endquote

v2: Also kill DRIVER_USE_MTRR as suggested by David Herrmann

v3: Rebase on top of David Herrmann's agp setup/cleanup changes.

Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: NAndy Lutomirski <luto@amacapital.net>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

So I've stumbled over drm_fasync and wondered what it does. Digging
that up is quite a story.

First I've had to read up on what this does and ended up being rather
bewildered why peopled loved signals so much back in the days that
they've created SIGIO just for that ...

Then I wondered how this ever works, and what that strange "No-op."
comment right above it should mean. After all calling the core fasync
helper is pretty obviously not a noop. After reading through the
kernels FASYNC implementation I've noticed that signals are only sent
out to the processes attached with FASYNC by calling kill_fasync.

No merged drm driver has ever done that.

After more digging I've found out that the only driver that ever used
this is the so called GAMMA driver. I've frankly never heard of such a
gpu brand ever before. Now FASYNC seems to not have been the only bad
thing with that driver, since Dave Airlie removed it from the drm
driver with prejudice:

commit 1430163b4bbf7b00367ea1066c1c5fe85dbeefed
Author: Dave Airlie <airlied@linux.ie>
Date:   Sun Aug 29 12:04:35 2004 +0000

    Drop GAMMA DRM from a great height ...

Long story short, the drm fasync support seems to be doing absolutely
nothing. And the only user of it was never merged into the upstream
kernel. And we don't need any fops->fasync callback since the fcntl
implementation in the kernel already implements the noop case
correctly.

So stop this particular cargo-cult and rip it all out.

v2: Kill drm_fasync assignments in rcar (newly added) and imx drivers
(somehow I've missed that one in staging). Also drop the reference in
the drm DocBook. ARM compile-fail reported by Rob Clark.

v3: Move the removal of dev->buf_asnyc assignment in drm_setup to this
patch here.

v4: Actually git add ... tsk.

Cc: Dave Airlie <airlied@linux.ie>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Clark <robdclark@gmail.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>