By adding tracepoint equivalents for WATCH_BUF/EXEC we are able to monitor
the lifetimes of objects, requests and significant events. These events can
then be probed using the tracing frameworks, such as systemtap and, in
particular, perf.

For example to record the stack trace for every GPU stall during a run, use

  $ perf record -e i915:i915_gem_request_wait_begin -c 1 -g

And

  $ perf report

to view the results.

[Updated to fix compilation issues caused.]
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ben Gamari <bgamari@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Add support for framebuffer compression on GM45 and above.  Removes
some unnecessary I915_HAS_FBC checks as well (this is now part of the
FBC display function).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

This patch splits out several of the display functions into a separate
display function table to avoid tons of chipset specific if..else
if..else if blocks all over.  There are more opportunities for this
(some noted in the structure defintition); so more cleanup patches will
follow.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

If the presumed_offset as feed to userspace and returned to the kernel
from a previous execbuffer is still valid, then we do not need to rewrite
the relocation entry and may skip the offset sanity checks.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Eric noted a potential concern with the low bits not being strictly used
as part of the absolute offset (instead part of the command stream to the
GPU), but in practice that should not be an issue.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Andy Whitcroft <apw@canonical.com>
Cc: Eric Anholt <eric@anholt.net>
CC: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We usually don't have an SAREA, and we always want to update the FBC
status anyway, so move the update up above the various master/sarea
checks.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

It reports closed when open, leading to "no outputs found" at startup
unless a VGA cable is plugged in.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Yakui pointed out that we don't properly no-op the ACPI button routines
if the button driver isn't built in.  This will cause problems if ACPI
is disabled, so provide stub functions in that case.
Reported-by: ykzhao <yakui.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

A very high dotclock (e.g. 229500kHz as reported by Anton) can cause
the entries_required variable to overflow, potentially leading to a
FIFO watermark value that's too low to support the given mode.  Split
the division across the calculation to avoid this.

Cc: stable@kernel.org
Reported-by: Anton Khirnov <wyskas@gmail.com>
Tested-by: Anton Khirnov <wyskas@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

By handling latency variable efficiently we also get rid of this warning :

  CC [M]  drivers/gpu/drm/i915/intel_display.o
drivers/gpu/drm/i915/intel_display.c: In function ‘igd_enable_cxsr’:
drivers/gpu/drm/i915/intel_display.c:1918: warning: ‘latency’ may be used uninitialized in this function
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Don't need extra config restore like for intel_agp, which
might cause resume hang issue found by Alan on 845G.

Cc: Stable Team <stable@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Due to the necessity of having to take the struct_mutex, the i915
shrinker can not free the inactive lists if we fail to allocate memory
whilst processing a batch buffer, triggering an OOM and an ENOMEM that
is reported back to userspace. In order to fare better under such
circumstances we need to manually retry a failed allocation after
evicting inactive buffers.

To do so involves 3 steps:
1. Marking the backing shm pages as NORETRY.
2. Updating the get_pages() callers to evict something on failure and then
   retry.
3. Revamping the evict something logic to be smarter about the required
   buffer size and prefer to use volatile or clean inactive pages.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Similar to the madvise() concept, the application may wish to mark some
data as volatile. That is in the event of memory pressure the kernel is
free to discard such buffers safe in the knowledge that the application
can recreate them on demand, and is simply using these as a cache.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This should help GEM handle memory pressure sitatuions more gracefully.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

There is no need to store the gtt_alignment as it is either explicitly
set according to the hardware requirements (e.g. scanout) or the
minimum alignment is computed on demand.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

If we failed to set the domain, the buffer was no longer being tracked
on any list.

Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Due to a bogus FBC support check and failing to check for FBC support
in the right places, mode setting on non-mobile platforms could fail
and hang in the FBC disable routine.  Fix it up.

This fix highlights the need for cleanups in this area (function
pointers and better feature support checks).  Patches for that to
follow.
Tested-by: Kenny Graunke <kenny@whitecape.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We now unconditionally restore the mode at lid open time since some
platforms turn off the panel, pipes or other display elements when the
lid is closed.  There's a problem with doing this at resume time
however.

At resume time, we'll get a lid event, but restoring the mode at that
time may not be safe (e.g. if we get the lid event before global state
has been restored), so check the suspended state and make sure our
restore is locked against other mode updates.
Tested-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

There is a very real possibility that multiple CPUs will notice that the
GPU is wedged. This introduces all sorts of potential race conditions.
Make the wedged flag atomic to mitigate this risk.
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This patch uses the previously introduced chip reset logic to reset the
chip when an error event is detected.
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This patch puts in place the machinery to attempt to reset the GPU. This
will be used when attempting to recover from a GPU hang.
Signed-off-by: Owain G. Ainsworth <oga@openbsd.org>
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We set a periodic timer to check on the GPU, resetting it every time a
batch is completed. If the timer elapses, we check acthd. If acthd
hasn't changed in two timer periods, we assume the chip is wedged.

This is implemented in such a way that it leaves the option open to
employ adaptive timer intervals in the future. One could wait until
several timer periods have elapsed before declaring the chip dead. If
the chip comes back after several periods but before the "dead"
threshold, the timer interval or dead threshold could be raised.

It is important to note that while checking for active requests, we need
to account for the fact that requests are removed from the list (i.e.
retired) in a deferred work queue handler. This means that merely
checking for an empty request_list is insufficient; the list could be
non-empty yet the GPU still idle, causing the hangcheck timer to
incorrectly mark the GPU as wedged (it took me a while to figure that
out---sigh...)
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We'll need it in i915_irq.c for checking whether there are outstanding
requests. Also, the function really ought to return a bool, not an int.
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We move the display-specific code into it's own functions, called
from the general GPU state save/restore functions. This will be needed
later by the GPU reset code.
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

i915_wait_request() only checks mm.wedged after it interacts with the
hardware, generally causing the driver to lock up waiting for a wedged
chip. Make sure we check mm.wedged as the first thing we do.
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

BLC_PWM_CTL2 is for 965+ only, so add device model check for
legacy backlight control.

For native backlight control, it maps the backlight value (0~255)
in opregion ASLE[BCLP] to backlight duty cycle (0~max_backlight)
and set into control register.

It also add support for IGD device, which follows opregion spec.
Signed-off-by: Li Peng <peng.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Arrandale has new window based method for panel fitting.
This one enables full screen aspect scaling on LVDS. It fixes
standard mode display failure on LVDS for Arrandale.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

This is not required on newer stepping hardware to get
reliable force detect status. Removing this fixes screen
blank flicker in CRT detect on IGDNG.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

IGDNG LVDS SSC uses 120Mhz freq. This fixes one
1600x900 LVDS panel black issue on IGDNG with SSC enabled.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

New register for PCH LVDS on IGDNG should be used.
This is a copy-n-paste typo. This fixes possible dual
channel LVDS panel failure on IGDNG.

Cc: Stable Team <stable@kernel.org>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

We want the compressed line length buffer address, not the framebuffer
address.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drm_ht_remove_item() does not handle removing an absent item and the hlist
in particular is incorrectly initialised. The easy remedy is simply skip
calling i915_gem_free_mmap_offset() unless we have actually created the
offset and associated ht entry.

This also fixes the mishandling of a partially constructed offset which
leaves pointers initialized after freeing them along the
i915_gem_create_mmap_offset() error paths.

In particular this should fix the oops found here:
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/415357/comments/8Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
Cc: stable@kernel.org

Ever since we enabled GEM, the pre-9xx chipsets (particularly 865) have had
serious stability issues.  Back in May a wbinvd was added to the DRM to
work around much of the problem.  Some failure remained -- easily visible
by dragging a window around on an X -retro desktop, or by looking at bugzilla.

The chipset flush was on the right track -- hitting the right amount of
memory, and it appears to be the only way to flush on these chipsets, but the
flush page was mapped uncached.  As a result, the writes trying to clear the
writeback cache ended up bypassing the cache, and not flushing anything!  The
wbinvd would flush out other writeback data and often cause the data we wanted
to get flushed, but not always.  By removing the setting of the page to UC
and instead just clflushing the data we write to try to flush it, we get the
desired behavior with no wbinvd.

This exports clflush_cache_range(), which was laying around and happened to
basically match the code I was otherwise going to copy from the DRM.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org>
Cc: stable@kernel.org

This patch adds framebuffer compression (good for about ~0.5W power
savings in the best case) support for pre-GM45 chips.  GM45+ have a new,
more flexible FBC scheme that will be added in a separate patch.

FBC can't always be enabled: the compressed buffer must be physically
contiguous and reside in stolen space.  So if you have a large display
and a small amount of stolen memory, you may not be able to take
advantage of FBC.  In some cases, a BIOS setting controls how much
stolen space is available.  Increasing this to 8 or 16M can help.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

With all the other lid pieces in place, it's easy to generate a uevent
for the LVDS connector just like we do for other outputs.  Should make
lid open/close fit in with the rest of a userland based output
reconfiguration scheme.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

We can't load or hotplug detect LVDS like we can other outputs, but if
there's a lid device present we can use it as a proxy.  This allows the
LFP state to be determined at ->detect time, making configurations
requiring manual intervention today "just work" assuming the lid device
status is correct.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

Some laptop platforms will disable pipes and/or planes at lid close time
and not restore them when the lid is opened again.  So catch the lid
event, and if the lid was opened, force a mode restore.

Fixes fdo bug #21230.
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

Some drivers need to know when a lid event occurs and get the current
status.  This can be useful for when a platform firmware clobbers some
hardware state at lid time, and a driver needs to restore things when
the lid is opened again.
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

Test on the IGD chip, which is a G33-like graphic device.
Signed-off-by: Li Peng <peng.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>