Amending
commit 4518f611
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Jan 23 16:16:35 2013 +0100

    drm/i915: dump UTS_RELEASE into the error_state

CC: stable@vger.kernel.org
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The shift changed, hurray.
Reported-by: NKenneth Graunke <kenneth@whitecape.org>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Useful for statistics or on overflowing bug reports to keep things all
lined up.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Useful for checking whether the new refcounting works as advertised.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Well, at least step 1. The goal here is that framebuffer objects can
survive outside of the mode_config lock, with just a reference held
as protection. The first step to get there is to introduce a special
fb_lock which protects fb lookup, creation and destruction, to make
them appear atomic.

This new fb_lock can nest within the mode_config lock. But the idea is
(once the reference counting part is completed) that we only quickly
take that fb_lock to lookup a framebuffer and grab a reference,
without any other locks involved.

vmwgfx is the only driver which does framebuffer lookups itself, also
wrap those calls to drm_mode_object_find with the new lock.

Also protect the fb_list walking in i915 and omapdrm with the new lock.

As a slight complication there's also the list of user-created fbs
attached to the file private. The problem now is that at fclose() time
we need to walk that list, eventually do a modeset call to remove the
fb from active usage (and are required to be able to take the
mode_config lock), but in the end we need to grab the new fb_lock to
remove the fb from the list. The easiest solution is to add another
mutex to protect this per-file list.

Currently that new fbs_lock nests within the modeset locks and so
appears redudant. But later patches will switch around this sequence
so that taking the modeset locks in the fb destruction path is
optional in the fastpath. Ultimately the goal is that addfb and rmfb
do not require the mode_config lock, since otherwise they have the
potential to introduce stalls in the pageflip sequence of a compositor
(if the compositor e.g. switches to a fullscreen client or if it
enables a plane). But that requires a few more steps and hoops to jump
through.

Note that framebuffer creation/destruction is now double-protected -
once by the fb_lock and in parts by the idr_lock. The later would be
unnecessariy if framebuffers would have their own idr allocator. But
that's material for another patch (series).

v2: Properly initialize the fb->filp_head list in _init, otherwise the
newly added WARN to check whether the fb isn't on a fpriv list any
more will fail for driver-private objects.

v3: Fixup two error-case unlock bugs spotted by Richard Wilbur.
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We have two important transitions of the wedged state in the current
code:

- 0 -> 1: This means a hang has been detected, and signals to everyone
  that they please get of any locks, so that the reset work item can
  do its job.

- 1 -> 0: The reset handler has completed.

Now the last transition mixes up two states: "Reset completed and
successful" and "Reset failed". To distinguish these two we do some
tricks with the reset completion, but I simply could not convince
myself that this doesn't race under odd circumstances.

Hence split this up, and add a new terminal state indicating that the
hw is gone for good.

Also add explicit #defines for both states, update comments.

v2: Split out the reset handling bugfix for the throttle ioctl.

v3: s/tmp/wedged/ sugested by Chris Wilson. Also fixup up a rebase
error which prevented this patch from actually compiling.

v4: To unify the wedged state with the reset counter, keep the
reset-in-progress state just as a flag. The terminally-wedged state is
now denoted with a big number.

v5: Add a comment to the reset_counter special values explaining that
WEDGED & RESET_IN_PROGRESS needs to be true for the code to be
correct.

v6: Fixup logic errors introduced with the wedged+reset_counter
unification. Since WEDGED implies reset-in-progress (in a way we're
terminally stuck in the dead-but-reset-not-completed state), we need
ensure that we check for this everywhere. The specific bug was in
wait_for_error, which would simply have timed out.

v7: Extract an inline i915_reset_in_progress helper to make the code
more readable. Also annote the reset-in-progress case with an
unlikely, to help the compiler optimize the fastpath. Do the same for
the terminally wedged case with i915_terminally_wedged.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

And to make Ben Widawsky happier, use the gpu_error instead of
the entire device as the argument in some functions.

Drop the outdated comment on ->wedged for now, a follow-up patch will
change the semantics and add a proper comment again.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This has been sprinkled all over the place in dev_priv. I think
it'd be good to also move all the code into a separate file like
i915_gem_error.c, but that's for another patch.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Mappable_end, ie. size is almost always what you want as opposed to the
number of entries. Since we already have that information, we can scrap
the number of entries and only calculate it when needed.

If gtt_start is !0, this will have slightly different behavior. This
difference can only occur in DRI1, and exists when we try to kick out
the firmware fb. The new code seems like a bugfix to me.

The other case where we've changed the behavior is during init we check
the mappable region against our current known upper and lower limits
(64MB, and 512MB). This now matches the comment, and makes things more
convenient after removing gtt_mappable_entries.

Also worth noting is the setting of mappable_end is taken out of setup
because we do it earlier now in the DRI2 case and therefore need to add
that tiny hunk to support the DRI1 IOCTL.

v2: Move up mappable end to before legacy AGP init

v3: Add the dev_priv inclusion here from previous rebase error in patch
5

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> (v2)
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: squash in fix for a printk format flag mismatch warning.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The purpose of the gtt structure is to help isolate our gtt specific
properties from the rest of the code (in doing so it help us finish the
isolation from the AGP connection).

The following members are pulled out (and renamed):
gtt_start
gtt_total
gtt_mappable_end
gtt_mappable
gtt_base_addr
gsm

The gtt structure will serve as a nice place to put gen specific gtt
routines in upcoming patches. As far as what else I feel belongs in this
structure: it is meant to encapsulate the GTT's physical properties.
This is why I've not added fields which track various drm_mm properties,
or things like gtt_mtrr (which is itself a pretty transient field).
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
[Ben modified commit messages]
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With the assertion from the previous patch in place, it should be safe
to get rid gtt_mappable_total. Keeps things saner to not have to track
the same info in two places.

In order to keep the diff as simple as possible and keep with the
existing gtt_setup semantics we opt to keep gtt_mappable_end. It's not
as consistent with the 'total' used in the previous patch, but that can
be fixed later.
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@gmail.com>
[Ben modified commit message]
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As a means to investigate some bad system behaviour related to the
purging of the active, inactive and unbound lists, it is useful to be
able to manually control when those lists should be cleared.

v2: use _safe list iterators as we kick objects from the list as we
walk.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add a small comment explaining why we don't need to check and
wait for gpu resets, acked by Chris on irc.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

These are useful for investigating hangs involving WAIT_FOR_EVENT.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Apply a droplet of Future-Proof in the if-ladder.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This debugs entry can be used to set arbitrary value to next_seqno.
Use i915_gem_set_seqno instead of poking next_seqno.

v2: nasty details of next_seqno and last_seqno handling
moved inside i915_gem_set_seqno as suggested by Chris Wilson.
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>

Spinning for up to 200 us with interrupts locked out is not good. So
let's just spin (and even that seems to be excessive).

And we don't call these functions from interrupt context, so this is
not required. Besides that doing anything in interrupt contexts which
might take a few hundred us is a no-go. So just convert the entire
thing to a mutex. Also move the mutex-grabbing out of the read/write
functions (add a WARN_ON(!is_locked)) instead) since all callers are
nicely grouped together.

Finally the real motivation for this change: Dont grab the modeset
mutex in the dpio debugfs file, we don't need that consistency. And
correctness of the dpio interface is ensured with the dpio_lock.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Before queuing the flip but crucially after attaching the unpin-work to
the crtc, we continue to setup the unpin-work. However, should the
hardware fire early, we see the connected unpin-work and queue the task.
The task then promptly runs and unpins the fb before we finish taking
the required references or even pinning it... Havoc.

To close the race, we use the flip-pending atomic to indicate when the
flip is finally setup and enqueued. So during the flip-done processing,
we can check more accurately whether the flip was expected.

v2: Add the appropriate mb() to ensure that the writes to the page-flip
worker are complete prior to marking it active and emitting the MI_FLIP.
On the read side, the mb should be enforced by the spinlocks.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
[danvet: Review the barriers a bit, we need a write barrier both
before and after updating ->pending. Similarly we need a read barrier
in the interrupt handler both before and after reading ->pending. With
well-ordered irqs only one barrier in each place should be required,
but since this patch explicitly sets out to combat spurious interrupts
with is staged activation of the unpin work we need to go full-bore on
the barriers, too. Discussed with Chris Wilson on irc and changes
acked by him.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

seqno's are u32 so print accordingly
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>

This is needed for testing seqno wrapping. Be careful to not bump next_seqno
more than 0x7FFFFFFF at a time (between some handled requests) as
i915_seqno_passed() can't handle bigger difference in between.

v2: Address review comments from Chris Wilson.
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Squash in fixup to properly remove the debugfs file on driver
unload again.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

- __iomem where there is none (I love how we mix these things up).
- Use gfp_t instead of an other plain type.
- Unconfuse one place about enum pipe vs enum transcoder - for the pch
  transcoder we actually use the pipe enum. Fixup the other cases
  where we assign the pipe to the cpu transcoder with explicit casts.
- Declare the mch_lock properly in a header.

There is still a decent mess in intel_bios.c about __iomem, but heck,
this is x86 and we're allowed to do that.

Makes-sparse-happy: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Use a space after the cast consistently and fix up the
newly-added cast in i915_irq.c to properly use __iomem.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In order to accommodate objects that are not backed by struct pages, but
instead point into a contiguous region of stolen space, we need to make
various changes to avoid dereferencing obj->pages or obj->base.filp.

First introduce a marker for the stolen object, that specifies its
offset into the stolen region and implies that it has no backing pages.
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>

As we do not have any domains occupying the high bits, there is no point
in always printing the leading 00.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Should be useful to know what the driver thought the other ring's seqno
was when it last used a semaphore.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fixes a WARN_ON in igt/tests/debugfs_reader

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

This allows the power related code to run independently of the rest of
the pipeline, extending the resume and init time improvements into
userspace, which would otherwise have been blocked on the struct mutex
if we were doing PCU communication.

v2: Also convert the locking for the rps sysfs interface.
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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>

There is a special mechanism for communicating with the PCU already
being used for the ring frequency stuff. As we'll be needing this for
other commands, extract it now to make future code less error prone and
the current code more reusable.

I'm not entirely sure if this code matches 1:1 with the previous code
behaviorally. Functionally however, it should be the same.

CC: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Fixup compile fail reported by Wu Fengguang.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

Remove redundant DRM UAPI header #inclusions from drivers/gpu/.

Remove redundant #inclusions of core DRM UAPI headers (drm.h, drm_mode.h and
drm_sarea.h).  They are now #included via drmP.h and drm_crtc.h via a preceding
patch.

Without this patch and the patch to make include the UAPI headers from the core
headers, after the UAPI split, the DRM C sources cannot find these UAPI headers
because the DRM code relies on specific -I flags to make #include "..."  work
on headers in include/drm/ - but that does not work after the UAPI split without
adding more -I flags.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

Magic numbers are bad mmmkay. In this case in particular the value is
especially weird because the docs say multiple things. We'll need this
value for sysfs, so extracting it is useful for that as well.
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
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>

For code consolidation and future maintainability.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-and-Tested-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Using the extracted INSTDONE reading, and our new register definitions,
update our hangcheck detection and error collection to use it. This
primarily means changing == to memcmp, and changing = to memcpy.
Hopefully this will give more info on error dump, and provide more
accurate hangcheck detection (both are actually TBD).

Also, remove the reading of instdone1 from the ring error collection
function, and just crap everything in capture_error_state (that could be
split into a separate patch if it wasn't so trivial).

v2: Now assuming i915_get_extra_instdone does the memset we can clean up the
code a bit (Jani)

v3: use ARRAY_SIZE as requested earlier by Jani (didn't change sizeof)
Updated commit msg

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

ERR_INT can generate interrupts. However since most of the conditions seem
quite fatal the patch opts to simply report it in error state instead of
adding more complexity to the interrupt handler for little gain (the
bits are sticky anyway).
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NAntti Koskipaa <antti.koskipaa@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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

When dealing with a working set larger than the GATT, or even the
mappable aperture when touching through the GTT, we end up with evicting
objects only to rebind them at a new offset again later. Moving an
object into and out of the GTT requires clflushing the pages, thus
causing a double-clflush penalty for rebinding.

To avoid having to clflush on rebinding, we can track the pages as they
are evicted from the GTT and only relinquish those pages on memory
pressure.

As usual, if it were not for the handling of out-of-memory condition and
having to manually shrink our own bo caches, it would be a net reduction
of code. Alas.

Note: The patch also contains a few changes to the last-hope
evict_everything logic in i916_gem_execbuffer.c - we no longer try to
only evict the purgeable stuff in a first try (since that's superflous
and only helps in OOM corner-cases, not fragmented-gtt trashing
situations).

Also, the extraction of the get_pages retry loop from bind_to_gtt (and
other callsites) to get_pages should imo have been a separate patch.

v2: Ditch the newly added put_pages (for unbound objects only) in
i915_gem_reset. A quick irc discussion hasn't revealed any important
reason for this, so if we need this, I'd like to have a git blame'able
explanation for it.

v3: Undo the s/drm_malloc_ab/kmalloc/ in get_pages that Chris noticed.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Split out code movements and rant a bit in the commit message
with a few Notes. Done v2]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since forcewake is now protected by a spinlock, we don't need to grab
dev->struct_mutex any more. This way we can also get rid of a stale
comment, noticed by Ben Widawsky while reviewing some locking changes.

v2: Kill the unused variable ret, noticed by Fengguang Wu.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Avoid the forcewake overhead when simply retiring requests, as often the
last seen seqno is good enough to satisfy the retirment process and will
be promptly re-run in any case. Only ensure that we force the coherent
seqno read when we are explicitly waiting upon a completion event to be
sure that none go missing, and also for when we are reporting seqno
values in case of error or debugging.

This greatly reduces the load for userspace using the busy-ioctl to
track active buffers, for instance halving the CPU used by X in pushing
the pixels from a software render (flash). The effect will be even more
magnified with userptr and so providing a zero-copy upload path in that
instance, or in similar instances where X is simply compositing DRI
buffers.

v2: Reverse the polarity of the tachyon stream. Daniel suggested that
'force' was too generic for the parameter name and that 'lazy_coherency'
better encapsulated the semantics of it being an optimization and its
purpose. Also notice that gen6_get_seqno() is only used by gen6/7
chipsets and so the test for IS_GEN6 || IS_GEN7 is redundant in that
function.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This way it's easier so see what belongs together, and what is used
by the ilk ips code. Also add some comments that explain the locking.

Note that (cur|min|max)_delay need to be duplicated, because
they're also used by the ips code.

v2: Missed one place that the dev_priv->ips change caught ...
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's no fun if your shell hangs when the driver has gone on vacation
and you want to know why ...
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>