Inspired by the recent ppgtt regression report, where switching of
dmar only for the gpu seems to fix things completely, I've looked
again at the semaphores+vt-d situation.

Contrary to my earlier testing a few months back my system is now
stable with dmar disabled for the igd, and not only when disabling
dmar completely.

So I'm rather hopeful that all our recent fixes for snb have changed
things for code and it's time to try enabling semaphores again. We've
also had issues with enabling semaphores which are not vt-d related,
but I guess these are all fixed by the autoreport-disabling and lazy
request fix. And there's only one way to find out whether there are
still other issues ...

When I've tried to apply this patch I've noticed that semaphores on
gen6 have already silently been enabled in

commit 2911a35b
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Thu Apr 5 14:47:36 2012 -0700

    drm/i915: use semaphores for the display plane

Fix this up by only checking whether dmar is enabled on the gfx (not
on the entire system).
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These two functions are actually hw-specific and only valid for gm45
thru gen7. HSW completely changes how this works, so label them
accordingly.

v2: s/gm45/g4x/ like for the previous patch.
Acked-by: NPaulo Zanoni <przanoni@gmail.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Generally we call stuff with i9xx_ when it's valid for gen3+. But
gen3 and early gen4 only support hdmi with sdvo cards, and writing
infoframes works completely different there.

v2: Use g4x instead of gm45 - it applies to the desktop variant, too.

v3: Properly align the paramters of g4x_write_infoframe again, noticed
by Paulo Zanoni.
Acked-by: NPaulo Zanoni <przanoni@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Simplifies things because for all the infoframes we care about,
we always send them on each vblank. Also, this gets rid of one
of the hw specific functions mislabelled with the intel_ prefix -
hsw will completely change how this works!
Acked-by: NPaulo Zanoni <przanoni@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The principle of intel_mark_busy() is that we want to spot the
transition of when the display engine is being used in order to bump
powersaving modes and increase display clocks. As such it is only
important when the display is changing, i.e. when rendering to the
scanout or other sprite/plane, and these are characterised by being
pinned.

v2: Mark the whole device as busy on execbuffer and pageflips as well
and rebase against dinq for the minor bug fix to be immediately
applicable.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: fix compile fail.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

intel_wait_for_vblank uses PIPESTAT, which does not exist on Ironlake
and newer, so now we use PIPEFRAME.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Ditch the check for disable pipe from the new ilk wait for
vblank function to keep it consisten with existing behaviour.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Just like Gen 4, IBX has a "Port Select" field on the DIP register,
but the ports are different.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

IBX does not need the workaround used in cpt_write_infoframe that
requires the AVI frame to be enabled while being updated.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The registers are on the PCH, so use the PCH name instead of the CPU
name. Also, the way this function is implemented is really only for
CPT and PPT. For now, both functions have the same implementations:
the next patch will fix ibx_write_infoframe.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Better safe than sorry. Currently we never change the frequency and
use the same for every infoframe type, so the only way to reproduce a
bug would be with the BIOS doing something.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

That's what the VIDEO_DIP_CTL documentation says we need to do. Except
when it's the AVI InfoFrame and we're ironlake_write_infoframe.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This will allow us to disable an infoframe without changing its
frequency.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Should prevent bugs when changing the port.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Make sure we're doing the right thing, just like we do on gen5+.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Don't use intermediate variables, change the value of 'val' as we go
through the function. The new style looks more similar to the rest of
our code. IMHO, it's also easier to read and change.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Gen3+ is 13 bits (12:0), and on gen2 only 12 (11:0). For both the high
bits are marked reserved, read-only so continue to mask them. Bit 31
is not reserved and has a meaning.
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>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While trying to fix up gen4 gpu reset in

commit f49f0586
Author: Kenneth Graunke <kenneth@whitecape.org>
Date:   Sat Sep 11 01:19:14 2010 -0700

    drm/i915: Actually set the reset bit in i965_reset

a little confusion about when wait_for times out has been introduced -
wait for loops _until_ the condition is true.

This fixes gpu reset on my gm45, testing with my hangman code shows
that it's now fairly reliable - it only died after well over 100 reset
cycles.

Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: NKenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On gen4+ we don't reset the display unit, so resetting the complete
modeset state should not be necessary.

We can't do reset on gen3 anyway, which leaves us with gen2 reset:
According to Chris Wilson, that doesn't work so great, so he suggested
we just ignore that. If the need ever arrises, we can re-add it later
on.
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... we actually use it.

Unfortunately we can't reset both at the same time without also
resetting the display unit, so do render and media separately.

Also replace magic constants with proper #defines.
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Only half of them even cared, and it's always the same one.
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- reset the stop_rings infrastructure while resetting the hw to
  avoid angering the hangcheck right away (and potentially declaring
  the gpu permanently wedged).

- ignore reset failures when hanging due to the hangman - we don't
  have reset code for all generations.

v2: Ensure that we only ignore reset failures when the hw reset is not
implemented and not when it failed.
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Slightly cleans up the code and could be useful for e.g. Ben
Widawsky's hw context patches.

v2: New colours!

Cc: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- need_display is always true, scrap it.
- don't reacquire the mutex to do nothing after having restored the
  gem state.
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... by writing (anything) to i915_error_state.

This way we can simulate a bunch of gpu hangs and run the error_state
capture code every time (without the need to reload the module).

To make that happen we need to abandon the simple seq_file wrappers
provided by the drm core. While at it put the new error_state
refcounting to some good use and associated the error_state to the
debugfs when opening the file. Otherwise the error_state could change
while someone is reading it. This should help greatly when we finally
get around to split up the giant single seq_file block that the
error_state file currently is into smaller parts.

v2: Actually squash all the fixes into the patch ...
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- reduce the irq disabled section, even for a debugfs file this was
  way too long.
- always disable irqs when taking the lock.

v2: Thou shalt not mistake locking for reference counting, so:
- reference count the error_state to protect from concurent freeeing.
  This will be only really used in the next patch.
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

gpu reset is a very important piece of our infrastructure.
Unfortunately we only really it test by actually hanging the gpu,
which often has bad side-effects for the entire system. And the gpu
hang handling code is one of the rather complicated pieces of code we
have, consisting of
- hang detection
- error capture
- actual gpu reset
- reset of all the gem bookkeeping
- reinitialition of the entire gpu

This patch adds a debugfs to selectively stopping rings by ceasing to
update the hw tail pointer, which will result in the gpu no longer
updating it's head pointer and eventually to the hangcheck firing.
This way we can exercise the gpu hang code under controlled conditions
without a dying gpu taking down the entire systems.

Patch motivated by me forgetting to properly reinitialize ppgtt after
a gpu reset.

Usage:

echo $((1 << $ringnum)) > i915_ring_stop # stops one ring

echo 0xffffffff > i915_ring_stop # stops all, future-proof version

then run whatever testload is desired. i915_ring_stop automatically
resets after a gpu hang is detected to avoid hanging the gpu to fast
and declaring it wedged.

v2: Incorporate feedback from Chris Wilson.

v3: Add the missing cleanup.

v4: Fix up inconsistent size of ring_stop_read vs _write, noticed by
Eugeni Dodonov.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The drm_mode->dtd conversion used the crtc timings, whereas the
dtd->drm_mod did not set these. Use the standard mode information, not
the crtc timings, in both cases to make these two functions proper
inverses of each another.

Note that this also kills the risk that we handle interlaced timings
inconsistently because the drm core uses half-frames for crtc timings,
whereas we need full frames. But interlaced support is pretty decently
broken anyway for sdvo encoders, so no big deal.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Our handling of the crtc timing computation has been nicely
cargo-culted with calls to drm_mode_set_crtcinfo sprinkled all over
the place. But with

commit f9bef081
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sun Apr 15 19:53:19 2012 +0200

    drm/i915: don't clobber the special upscaling lvds timings

and

commit ca9bfa7e
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Jan 28 14:49:20 2012 +0100

    drm/i915: fixup interlaced vertical timings confusion, part 1

we now only set the crtc timing fields in the encoder->mode_fixup
(lvds only) and in crtc->mode_fixup (for everyone else). And since

commit 75c13993
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Jan 28 23:48:46 2012 +0100

    drm/i915: fixup overlay checks for interlaced modes

the only places we actually need the crtc timings is in the mode_set
function.

I guess the idea of the drm core is that every time it creates a drm
mode, it also sets the timings. But afaics it never uses them, safe
for the precise vblank timestamp code (but that can only run on active
modes, i.e.  after our mode_fixup functions have been called). The
problem is that drm core always sets CRTC_INTERLACE_HALVE_V, so the
timings are pretty much bogus for us anyway (at least with interlaced
support).

So I guess it's the drivers job that every active modes needs to have
crtc timings that suits it, and with these patches we should have
that. drm core doesn't seem to care about modes that just get passed
around. Hence we can now safely rip out all the remaining calls to
set_crtcinfo left in the driver and clean up this confusion.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Every time we use the device after a period of idleness, check that the
power management setup is still sane. This is to workaround a bug
whereby it seems that we begin suppressing power management interrupts,
preventing SandyBridge+ from going into turbo mode.

This patch does have a side-effect. It removes the mark-busy for just
moving the cursor - we don't want to increase the render clock just for
the sprite, though we may want to bump the display frequency. I'd argue
that we do not, and certainly don't want to take the struct_mutex here
due to the large latencies that introduces.

References: https://bugs.freedesktop.org/show_bug.cgi?id=44006Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While testing with the intel_infoframes tool on gen4, I see that when
video DIP is disabled, what we write to the DATA memory is not exactly
what we read back later.

This regression has been introduce in

commit 64a8fc01
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Thu Sep 22 11:16:00 2011 +0530

    drm/i915: fix ILK+ infoframe support

That commit was setting VIDEO_DIP_CTL to 0 when initializing, which
caused the problem.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43947
Cc: stable@kernel.org
Tested-by: NYang Guang <guang.a.yang@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
[danvet: Pimped commit message by using the usual commit citation
layout.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

They require an AVI InfoFrame with a proper Pixel Repetition field.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45729Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To keep the consistency with the other fields.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NAdam Jackson <ajax@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

When initialising the PLL registers we may have to clear existing state
from the BIOS - that is the PLL may already be enabled. So we need to
disable it, wait for the clocks to settle and then rewrite it.

The issue came to light when Ben tested

commit 88ca4bb7974277793e602d88739d4e8f56b89e64
Author: Jesse Barnes <jbarnes@virtuousgeek.org>
Date:   Fri Apr 20 17:11:53 2012 +0100

    drm/i915: manage PCH PLLs separately from pipes

and found that booting into a VGA monitor was no longer working. Closer
inspection suggests that it was a pre-existing bug now being hit by the
rearranged code. Perhaps Ben was not even the first person to stumble
upon this bug, https://bugs.freedesktop.org/show_bug.cgi?id=37029.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reported-and-Tested-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Unfortunately it looks like further vlv patches are still stalled due
to fried hw, and too many people are a bit annoyed about the unused
function warning.

So let's just rip it out, we can easily put it back in again.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The new wait_rendering ioctl also needs to check for an oustanding
lazy request, and we already duplicate that logic at three places. So
extract it.

While at it, also extract the code to check the gpu wedging state to
improve code flow.

v2: Don't use seqno as an outparam (Chris)

v3 by danvet: Kill stale comment and pimp commit message
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Because this is the place where we actually use the results of
them.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Two things:
- ring->virtual start is an __iomem pointer, treat it accordingly.
- dev_priv->status_page.page_addr is now always a cpu addr, no pointer
  casting needed for that.

Take the opportunity to remove the unnecessary drm indirection when
setting up the ringbuffer iomapping.

v2: Add a compiler barrier before reading the hw status page.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To get the fun stuff out of the way, the legacy hws is allocated by
userspace when the gpu needs a gfx hws. And there's no reference-counting
going on, so userspace can simply screw everyone over.

At least it's not as horrible as i810, where the ringbuffer is allocated
by userspace ...

We can't fix this disaster, but we can at least tidy up the code a
bit to make things clearer:
- Drop the drm ioremap indirection.
- Add a new new read_legacy_status_page to paper over the differences
  between the legacy gfx hws and the physical hws shared with the
  new ringbuffer code.
- Add a pointer in dev_priv->dri1 for the cpu addresses - that one is
  an iomem remapping as opposed to all other hw status pages. This is
  just prep work to make sparse happy.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>