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>

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>

We kzalloc dev_priv, and we never use hws_map in intel_ringbuffer.c.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

They're now in intel_pm.c, so group them a bit better.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We now have a nice home for power management code, so let's use it!

v2: Resolve conflict agains "Only enable IPS polling for gen5"
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Unfortunately there has been dri1 userspace that used gem to manage
the gtt and hence also needed cliprects in the execbuf ioctl. So
we can't ever remove that code without breaking the ioctl abi.

But at least we can disable it on gen5+, because these horrible
versions of mesa have not supported these chips.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Wohoo!

Now we only need to move all the gem/kms stuff that accidentally
landed in i915_dma.c out of it, and this will be our legacy dri1
grave-yard.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... and hide it in i915_dma.c.

This way all the legacy stuff dealing with READ_BREADCRUMB and
LP_RING and friends is in i915_dma.c.

v2: Rebase on top of Chris Wilson's rework irq handling code.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Let's just get this out of the way.

v2: Rebase against ENODEV changes.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We never supported dri1 on gen5+.

VLV never had that code, so no need to remove it.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is a pretty racy way to close these races, and we have
much better means to cope with these races meanwhile: For
non-broken userspace we correctly wait for any outstanding
rendering, for broken userspace the hangcheck will save the
day.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The LP refers to 'low priority' as opposed to the high priority
ring on gen2/3. So lets constrain its use to the code of that era.

Unfortunately we can't yet completely remove the associated
macros from common headers and shove them into i915_dma.c to
the other dri1 legacy support code, a few cleanups are still
missing for that.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Assigned in setparam, used never.

I didn't bother to dig through the archives to figure out what
this was supposed to do.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Even the horrible gen3 XvMC code has learned to do this
right by the time xf86-video-intel releases learned to do
kernel modesetting. So we can just disallow this.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... and shove allow_batchbuffer in there. More dragons will
follow suit.

There's the curious case that we allow this for KMS ...
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

i915_dma.c contains most of the old dri1 horror-show, so move
the remaining bits there, too. The code has been removed and
the only thing left are some stubs to ensure that userspace
doesn't try to use this stuff. vblank_pipe_set only returns 0
without any side-effects, so we can even stub it out with
the canonical drm_noop.

v2: Rebase against ENODEV changes.
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

vblank_pipe was intended to be used for tracking DRI1 state. However,
the vblank_pipe reported to DRI1 is fixed to umask both pipes, and the
dev_priv->vblank_pipe unused and superfluous.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

On SandyBridge IPS was entirely implemented in hardware and not reliant
on the driver monitoring power consumption and feeding back desired run
states, so the hardware is able to adapt quicker and more flexibly. Which
is a huge relief for us as we no longer have to carry empirically
derived magic algorithms.

Yet despite the advance in technology, the driver was still doing its
IPS polling on all machines. Restrict it to the only supported hardware,
Clarkdale/Arrandale.
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>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It turns out throttle had an almost identical  bit of code to do the
wait. Now we can call the new helper directly.  This is just a bonus,
and not needed for the overall series.

v2: remove irq_get/put which is now in __wait_seqno (Ben)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's about to go away anyway. Just here to help bisection.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

i915_wait_request is actually a fairly large function encapsulating
quite a few different operations. Because being able to wait on seqnos
in various conditions is useful, extracting that bit of code to a helper
function seems useful

v2: pull the irq_get/put as well (Ben)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The only time irq_get should fail is during unload or suspend. Both of
these points should try to quiesce the GPU before disabling interrupts
and so the atomic polling should never occur.

This was recommended by Chris Wilson as a way of reducing added
complexity to the polled wait which I introduced in an RFC patch.

09:57 < ickle_> it's only there as a fudge for waiting after irqs
after uninstalled during s&r, we aren't actually meant to hit it
09:57 < ickle_> so maybe we should just kill the code there and fix the breakage

v2: return -ENODEV instead of -EBUSY when irq_get fails
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The waiting_seqno is not terribly useful, and as such we can remove it
so that we'll be able to extract lockless code.

v2: Keep the information for error_state (Chris)
Check if ring is initialized in hangcheck (Chris)
Capture the waiting ring (Chris)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: add some bikeshed to clarify a comment.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This extra bit of interrupt enabling code doesn't belong in the wait
seqno function. If anything we should pull it out to a helper so the
throttle code can also use it. The history is a bit vague, but I am
going to attempt to just dump it, unless someone can argue otherwise.

Removing this allows for a shared lock free wait seqno function. To keep
tabs on this issue though, the IER value is stored on error capture
(recommended by Chris Wilson)

v2: fixed typo EIR->IER (Ben)
Fix some white space (Ben)
Move IER capture to globally instead of per ring (Ben)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: ier is a 16 bit reg on gen2!]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This originates from a hack by me to quickly fix a bug in an earlier
patch where we needed control over whether or not waiting on a seqno
actually did any retire list processing. Since the two operations aren't
clearly related, we should pull the parameter out of the wait function,
and make the caller responsible for retiring if the action is desired.

The only function call site which did not get an explicit retire_request call
(on purpose) is i915_gem_inactive_shrink(). That code was already calling
retire_request a second time.

v2: don't modify any behavior excepit i915_gem_inactive_shrink(Daniel)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've missed this one.

v2: Chris Wilson noticed another register.
v3: Color choice improvements.
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>

Since there is only one remaining user of I915_INTERRUPT_ENABLE_FIX,
expand it at the callsite. Quoting Jesse Barnes:

"I'd really like to get rid of these defines at the top of i915_irq.c.
Some are unused and the others just make you check for the right bits
everytime your read the code."
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Add bikeshed suggested by Jesse.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We appear to allow too many pending pageflips as evidenced by an
apparent pin-leak. So borrow the pageflip completion logic from i8xx for
handling PendingFlip in a robust manner.

v2: Address Jesse's reminders about the nuances of gen3 IRQ handling.

References: https://bugzilla.kernel.org/show_bug.cgi?id=41882Signed-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>