On SNB and IVB, there's an MSR (also exposed through MCHBAR) we can use
to read out the amount of energy used over time.  Expose this in sysfs
to make it easy to do power comparisons with different configurations.

If the platform supports it, the file will show up under the
drm/card0/power subdirectory of the PCI device in sysfs as gt_energy_uJ.
The value in the file is a running total of energy (in microjoules)
consumed by the graphics device.

v2: move to sysfs (Ben, Daniel)
    expose a simple value (Chris)
    drop unrelated hunk (Ben)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

v3: by Ben
Tied it into existing rc6  sysfs entries and named that a more generic
"power attrs." Fixed rebase conflicts.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>

v4: Since RAPL is a real driver that already exists to serve power
monitoring, place our entry in debugfs. This gives me a fallback
location for systems that do not expose it otherwise.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The code directly uses the registers and ring->mmio_base.
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This define hasn't been used since:

  commit cfdf1fa2
  Author: Kristian Høgsberg <krh@bitplanet.net>
  Date:   Wed Dec 16 15:16:16 2009 -0500

      drm/i915: Implement IS_* macros using static tables
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The code using this was removed in:

  commit 88f23b8f
  Author: Chris Wilson <chris@chris-wilson.co.uk>
  Date:   Sun Dec 5 15:08:31 2010 +0000

      drm/i915: Avoid using PIPE_CONTROL on Ironlake
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This define hasn't been used since:

  commit 652c393a
  Author: Jesse Barnes <jbarnes@virtuousgeek.org>
  Date:   Mon Aug 17 13:31:43 2009 -0700

      drm/i915: add dynamic clock frequency control
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The existing code was trying different vswing and preemphasis settings
in the wrong place, and wasn't trying them enough.  So add a loop to
walk through them, properly disabling FDI TX and RX in between if a
failure is detected.

v2: remove unneeded reg writes, add delays around bit lock checks (Jesse)
v3: fix TX and RX disable per spec (Paulo)
    fix delays per spec (Paulo)
    make RX symbol lock check match TX bit lock check (Paulo)
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=51983Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The vma will [possibly] be destroyed during unbind in eviction.
Immediately after this, we try to delete the list entry.

Chris and Ville did the debug on this before I woke up, I just get to
take credit for the fix :p

For future reference the Oops that Mika reported:

[  403.472448] BUG: unable to handle kernel paging request at 6b6b6b6b
[  403.472473] IP: [<c12c1500>] __list_del_entry+0x20/0xe0
[  403.472514] *pdpt = 000000002e89c001 *pde = 0000000000000000
[  403.472556] Oops: 0000 [#1] SMP
[  403.472582] Modules linked in: mxm_wmi snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi psmouse snd_seq_midi_event snd_seq serio_raw snd_timer snd_seq_device snd soundcore snd_page_alloc wmi bnep rfcomm bluetooth mac_hid parport_pc ppdev lp parport usbhid dm_crypt firewire_ohci firewire_core crc_itu_t i915 drm_kms_helper e1000e ptp drm i2c_algo_bit pps_core xhci_hcd video
[  403.472895] CPU: 2 PID: 1940 Comm: Xorg Not tainted 3.11.0-rc2+ #827
[  403.472938] Hardware name:                  /DZ77BH-55K, BIOS BHZ7710H.86A.0070.2012.0416.2117 04/16/2012
[  403.473002] task: ec866c00 ti: ee6a2000 task.ti: ee6a2000
[  403.473039] EIP: 0060:[<c12c1500>] EFLAGS: 00013202 CPU: 2
[  403.473078] EIP is at __list_del_entry+0x20/0xe0
[  403.473109] EAX: f016d9bc EBX: f016d9bc ECX: 6b6b6b6b EDX: 6b6b6b6b
[  403.473151] ESI: 00000000 EDI: ee6a3c90 EBP: ee6a3c60 ESP: ee6a3c48
[  403.473193]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[  403.473230] CR0: 80050033 CR2: 6b6b6b6b CR3: 2ec43000 CR4: 001407f0
[  403.473271] Stack:
[  403.473285]  f63b2ff0 f61f98c0 f61f8000 f016d9bc 00000000 f016d9bc ee6a3cac f8519a4a
[  403.473347]  00000000 00000000 10000000 f61f8000 0100a000 10000000 00000001 008ca000
[  403.473410]  f64ee840 f61f98c0 f016d9bc f016dcec ee6a3c98 ee6a3c98 f61f98c0 dcc58f00
[  403.473472] Call Trace:
[  403.473509]  [<f8519a4a>] i915_gem_evict_something+0x17a/0x2d0 [i915]
[  403.473567]  [<f8516ed1>] i915_gem_object_pin+0x271/0x660 [i915]
[  403.473622]  [<f851c740>] ? i915_ggtt_clear_range+0x20/0x20 [i915]
[  403.473676]  [<f8517afa>] i915_gem_object_pin_to_display_plane+0xda/0x190 [i915]
[  403.473742]  [<f852d9fa>] intel_pin_and_fence_fb_obj+0xba/0x140 [i915]
[  403.473800]  [<f852db40>] intel_gen7_queue_flip+0x30/0x1c0 [i915]
[  403.473856]  [<f85337b0>] intel_crtc_page_flip+0x1a0/0x320 [i915]
[  403.473911]  [<f847b549>] ? drm_framebuffer_reference+0x39/0x80 [drm]
[  403.473965]  [<f847f9fb>] drm_mode_page_flip_ioctl+0x28b/0x320 [drm]
[  403.474018]  [<f846fec8>] drm_ioctl+0x4b8/0x560 [drm]
[  403.474064]  [<f847f770>] ? drm_mode_gamma_get_ioctl+0xd0/0xd0 [drm]
[  403.474113]  [<c1140f8a>] ? do_sync_read+0x6a/0xa0
[  403.474154]  [<f846fa10>] ? drm_copy_field+0x80/0x80 [drm]
[  403.474193]  [<c115134c>] do_vfs_ioctl+0x7c/0x5b0
[  403.474228]  [<c1141d2f>] ? vfs_read+0xef/0x160
[  403.474263]  [<c108dcbb>] ? ktime_get_ts+0x4b/0x120
[  403.474298]  [<c1151917>] SyS_ioctl+0x97/0xa0
[  403.474330]  [<c1590bc1>] sysenter_do_call+0x12/0x22
[  403.474364] Code: 55 f4 8b 45 f8 e9 75 ff ff ff 90 55 89 e5 53 83 ec 14 8b 08 8b 50 04 81 f9 00 01 10 00 74 24 81 fa 00 02 20 00 0f 84 8e 00 00 00 <8b> 1a 39 d8 75 62 8b 59 04 39 d8 75 35 89 51 04 89 0a 83 c4 14
[  403.474566] EIP: [<c12c1500>] __list_del_entry+0x20/0xe0 SS:ESP 0068:ee6a3c48
[  403.476513] CR2: 000000006b6b6b6b

v2: Missed the drm_object_unreference use after free (Ville)
Daniel Vetter <daniel@ffwll.ch> writes:
Reported-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Add the Oops from Mika to the commit message.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

In the new execbuf code we want to track buffers using the vmas even
before they're all properly mapped. Which means that bind_to_vm needs
to deal with buffers which have preallocated vmas which aren't yet
bound.

This patch implements this prep work and adjusts our WARN/BUG checks.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Split out from Ben's big execbuf patch. Also move one BUG
back to its original place to deflate the diff a notch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The execbuf wants to do relocations usings vmas, so we need a
vma->exec_list. The eviction code also uses the old obj execbuf list
for it's own book-keeping, but would really prefer to deal in vmas
only. So switch it over to the new list.

Again this is just a prep patch for the big execbuf vma conversion.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Split out from Ben's big execbuf vma patch.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

To convert the execbuf code over to use vmas natively we need to
shuffle the exec_list a bit. This patch here just prepares things with
the debugfs code, which also uses the old exec_list list_head, newly
called obj_exec_link.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: Split out from Ben's big patch.]
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>

Our driver initialization doesn't seem to be ready to load when the
power well is disabled: we hit a few "Unclaimed register" messages. So
do just like we already do for the suspend/resume path: enable the
power well before unloading.

At some point we'll want to be able to survive suspend/resume and
load/unload with the power well disabled, but for now let's just fix
the regression.

Regression introduced by the following commit:

commit bf51d5e2
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Wed Jul 3 17:12:13 2013 -0300
    drm/i915: switch disable_power_well default value to 1

Bug can be reproduced by running the "module_reload" script from
intel-gpu-tools.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67813Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Makes it more obviously correct what tricks we play by reusing the drm
prime release helper.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This fixes a WARN in i915_gem_free_object when the
obj->pages_pin_count isn't 0.

v2: Add locking to unmap, noticed by Chris Wilson. Note that even
though we call unmap with our own dev->struct_mutex held that won't
result in an immediate deadlock since we never go through the dma_buf
interfaces for our own, reimported buffers. But it's still easy to
blow up and anger lockdep, but that's already the case with our ->map
implementation. Fixing this for real will involve per dma-buf ww mutex
locking by the callers. And lots of fun. So go with the duct-tape
approach for now.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Tested-by: Armin K. <krejzi@email.com> (v1)
Acked-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Un-masking all PM interrupts causes hardware to generate
interrupts regardless of whether the interrupts are enabled
on the DE side. Since turbo only need up/down threshold and
rc6 timeout interrupt, mask all other interrupts bits to avoid
unnecessary overhead/wake up.

Note that our interrupt handler isn't being fired since we do set the
IER bits properly (IIR bits aren't set). The overhead isn't because
our driver is reacting to these interrupts, but because hardware keeps
generating internal messages when PMINTRMSK doesn't mask out the
up/down EI interrupts (which happen periodically).

Change-Id: I6c947df6fd5f60584d39b9e8b8c89faa51a5e827
Signed-off-by: NVinit Azad <vinit.azad@intel.com>
[danvet: Add follow-up explanation of the precise effects from Vinit
as a note to the commit message.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Whenever I need to work with the HSW_PWER_WELL_* register bits I have
to look at the documentation to find out which bit is to request the
power well and which one shows its current state. Rename the bits so I
won't need to look the docs every time.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

If the power well is disabled VGA is guaranteed to be disabled.

This fixes unclaimed register messages that happen on suspend/resume.

v2: Check the actual hw power well state instead of our own tracking
to make sure VGA is _really_ off (in case the BIOS/KVMr has just its
own request bit set). Requested by Ville.

Note: Ville suggested whether it wouldn't be better to just enable the
power well over a slightly longer time in our resume code, since we
already do that. I tend to agree, but there's also the modeset force
code in the lid notifier which _also_ eventually calls redisable_vga.
We shouldn't ever need this on somewhat modern hw (everything with
opregion essentially) but the code to bail out isn't there. Hence
stick with this simple approach here for now.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67517Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Summarize the discussion around the resume sequence and lid
notifier a bit.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

By our earlier reckoning, move from a snooped/llc setting to an uncached
setting, leaves the CPU cache in a consistent state irrespective of our
domain tracking - so we can forgo the warning about the lack of
invalidation. Similarly for any writes posted to the snooped CPU domain,
we know will be safely clflushed to the uncached PTEs after forcing the
domain change.

This WARN started to pop up with

commit d46f1c3f
Author:     Chris Wilson <chris@chris-wilson.co.uk>
AuthorDate: Thu Aug 8 14:41:06 2013 +0100

    drm/i915: Allow the GPU to cache stolen memory

Ville brought up a scenario where the interaction of a set_caching
ioctl call from userspace on a scanout buffer (i.e. obj->pin_display
is set) resulted in the code getting confused and not properly
flushing stale cpu cachelines. Luckily we already prevent this by
rejecting caching changes when obj->pin_count is set.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68040Tested-by: Ncancan,feng <cancan.feng@intel.com>
[danvet: Add buglink, bisect result and explain why Ville's scenario
is already taken care of.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The conditional is usually a recoverable driver bug, and so WARNing, and
preventing the drm_mm code from doing potential damage (BUG) is
desirable.

This issue was hit and fixed twice while developing the i915 multiple
address space code. The first fix is the patch just before this, and is
hit on an not frequently occuring error path. Another was fixed during
patch iteration, so it's hard to see from the patch:

commit c6cfb325
Author: Ben Widawsky <ben@bwidawsk.net>
Date:   Fri Jul 5 14:41:06 2013 -0700

    drm/i915: Embed drm_mm_node in i915 gem obj

From the intel-gfx mailing list, we discussed this:
References: <20130705191235.GA3057@bwidawsk.net>

Cc: Dave Airlie <airlied@redhat.com>
CC: <dri-devel@lists.freedesktop.org>
Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Acked-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Use () to make for neater alignment of the split lines, too. With this
we ditch another jump through the obj_gtt_size/offset indirection
maze.

Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Cleanup the map and fenceable setting during bind to make more sense,
and not check i915_is_ggtt() 2 unnecessary times

v2: Move the bools into the if block (Chris) - There are ways to tidy
this function (fence calculations for instance) even further, but they
are quite invasive, so I am punting on those unless specifically asked.

v3: Add newline between variable declaration and logic (Chris)
Recommended-by: NChris Wilson <chris@chris-wilson.co.uk>
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>

VMAs can be created and not bound. One may think of it as lazy cleanup,
and safely gloss over the conditions which manufacture it. In either
case, when the object backing the i915 vma is destroyed, we must cleanup
the vma without stumbling into a bunch of pitfalls that assume the vma
is bound.

NOTE: I was pretty certain the above condition could only happen when we
introduced the use of VMAs being looked up at execbuf, and already
existing. Paulo has hit this though, so I must be missing something. As
I believe the patch is correct anyway, therefore I won't scratch my head
too hard.

v2: use goto destroy as a compromise (Chris)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
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>

Use the standard inversely ordered goto label stack for everything.
Spotted while reviewing place where we might need to to call
vma_destroy but failed to do so.

Cc: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Ideally we could use for_each_ring with the ring flags as I've done a
couple times
(http://lists.freedesktop.org/archives/intel-gfx/2013-June/029450.html).
Until Daniel merges that patch though, we can just use this.

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We require n-1 mailboxes for proper semaphore synchronization. All
semaphore synchronization code relies on proper values in these
mailboxes. The fact that we failed to touch the vebox ring by itself
was unlikely to be an issue since the HW should be initializing the
values to 0. However the error framework for testing seqno wrap
introduced by Mika, in addition to the hangcheck via seqno, and
i915_error_first_batchbuffer() combined caused a nice explosion.

The problem is caused by seqno wrap because the wrap condition is not
properly setup. The wrap code attempts to set the sync mailboxes all
to 0, and then set the current seqno to one less than 0. In all cases,
the vebox mailbox wasn't properly being initialized. This caused a
wrap to not occur. When hangcheck kicks in with the bogus seqno
values, the rest just doesn't work. It makes me wonder if we shouldn't
consider a dumber version of hangcheck...

How we messed this up: VECS support was written before the
aforementioned other features. Upon VECS being rebased, these facts
were missed.

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=65387
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67198Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's basically the same deal as the RC6+ issues on ivy bridge
except this time with RC6 on sandy bridge. Like last time the
core of the issue is that the timings don't work 100% with our
voltage regulator. So from time to time, the kernel will print
a warning message about the GPU not getting out of RC6. In
particular, I found this fairly easy to reproduce during
suspend/resume.

Changing the threshold to 125000 instead of 50000 seems to fix
the issue. The previous patch used 150000 but as it turns out
this doesn't work everywhere. After getting such a machine, I
bisected the highest value which works, which is 125000, so here
it is.

I also measured the idle power usage before/after this patch and
didn't see a difference on a sandy bridge laptop. On haswell and
up, it makes a big difference, so we want to keep it at 50k
there. It also seems like haswell doesn't have the RC6 issues
that sandy bridge has so the 50k value is fine.
Signed-off-by: NStéphane Marchesin <marcheu@chromium.org>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The machines that fall in this category are the SDVs that have a PCI
ID starting with 0x0C. These are very early pre-production machines
and may not fully work. Other Haswell SDVs have PCI IDs that match the
real Haswell machines and we expect them to work better.

Even though they have problems, they still mostly work so I don't see
a reason to refuse loading our driver. But I do see a reason to reject
bug reports from these machines, so the message should help the bug
triagers.

As far as I know, we don't implement some workarounds that are
specific to these machines and suspend/resume may not work on most of
them, but besides this, they may work.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61508Signed-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>

After computing the stage changes for the set_config, record those in
the debug log.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Caught by "make W=1 drivers/gpu/drm/i915/".
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is primarily for the benefit of the create2 ioctl so that the
caller can avoid the later step of rebinding the bo with new PTE bits.
After introducing WT (and possibly GFDT) cacheing for display targets,
not everything in the display is earmarked as UC, and more importantly
what is is controlled by the kernel.

Note that set_cache_level/get_cache_level for DISPLAY is not necessarily
idempotent; get_cache_level may return UC for architectures that have no
special cache domain for the display engine.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Haswell GT3e has the unique feature of supporting Write-Through cacheing
of objects within the eLLC/LLC. The purpose of this is to enable the display
plane to remain coherent whilst objects lie resident in the eLLC/LLC - so
that we, in theory, get the best of both worlds, perfect display and fast
access.

However, we still need to be careful as the CPU does not see the WT when
accessing the cache. In particular, this means that we need to flush the
cache lines after writing to an object through the CPU, and on
transitioning from a cached state to WT.

v2: Actually do the clflush on transition to WT, nagging by Ville.
v3: Flush the CPU cache after writes into WT objects.
v4: Rease onto LLC updates and report WT as "uncached" for
get_cache_level_ioctl to remain symmetric with set_cache_level_ioctl.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Although I could not reproduce this (different compiler version,
perhaps), reportedly we get:

drivers/gpu/drm/i915/i915_irq.c:1943:27: warning: ‘score’ may be used
uninitialized in this function [-Wuninitialized]

Drop the 'score' variable altogether as it's not really needed.
Reported-by: NKees Cook <keescook@chromium.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 short lowercase names are bound to collide. The default warnings
don't even warn about shadowing.
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>

It's been there since i8xx_irq_handler() was added in
commit c2798b19
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sun Apr 22 21:13:57 2012 +0100

    drm/i915: i8xx interrupt handler
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>

Some Poulsbo cards seem to incorrectly report
SDVO_CMD_STATUS_TARGET_NOT_SPECIFIED instead of
SDVO_CMD_STATUS_PENDING, which causes the display to be turned off.

This could also happen to i915.
Signed-off-by: NGuillaume Clement <gclement@baobob.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I just noticed in our code we don't really check the assertion, and
given some of the code I am changing in this area, I feel a WARN is very
nice to have.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
[danvet: s/&/&&/ to fix typo on the check.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Resolve the catch-22 of igt needing a stable number and patches first
needing testcases by reserving the interface number up-front.

v2: Improve the spelling a bit.

v3: More spelling fail spotted by Chris.
Requested-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Now that we skip clflushes more often, return a boolean indicating
whether the clflush was actually performed, and only if it was do the
chipset flush. (Though on most of the architectures where the clflush will
be skipped, the chipset flush is a no-op!)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
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>

As a corollary to reviewing the interaction between LLC and our cache
domains, the GPU PTE bits are independent of the CPU PAT bits. As such
we can set the cache level on stolen memory based on how we wish the GPU
to cache accesses to it. So we are free to set the same default cache
levels as for normal bo, i.e. enable LLC cacheing by default where
appropriate.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

As mentioned in the previous commit, reads and writes from both the CPU
and GPU go through the LLC. This gives us coherency between the CPU and
GPU irrespective of the attribute settings either device sets. We can
use to avoid having to clflush even uncached memory.

Except for the scanout.

The scanout resides within another functional block that does not use
the LLC but reads directly from main memory. So in order to maintain
coherency with the scanout, writes to uncached memory must be flushed.
In order to optimize writes elsewhere, we start tracking whether an
framebuffer is attached to an object.

v2: Use pin_display tracking rather than fb_count (to ensure we flush
cursors as well etc) and only force the clflush along explicit writes to
the scanout paths (i.e. pin_to_display_plane and pwrite into scanout).

v3: Force the flush after hitting the slowpath in pwrite, as after
dropping the lock the object's cache domain may be invalidated. (Ville)

Based on a patch by Ville Syrjälä.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
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>