During a page fault and rebinding the buffer there exists a window for a
signal to arrive during the i915_wait_request() and trigger a
ERESTARTSYS. This used to be handled by returning SIGBUS and thereby
killing the application. Try 'cairo-perf-trace & cairo-test-suite' and
watch X go boom!

The solution as suggested by H. Peter Anvin is to simply return NOPAGE and
leave the higher layers to spot we did not fill the page and resubmit
the page fault.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
[anholt: Mostly squash it with another commit]

Only allow the user to mmap buffers that have not been marked as
purgeable.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In order to correctly prevent the invalid reuse of a purged buffer, we
need to track such events and warn the user before something bad
happens.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Whilst cleaning up the patches for submission, I mis-classified non-dirty
objects as purgeable. This was causing the backing pages for those
objects to be evicted under memory-pressure, discarding valid and
unreplaceable texture data.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As evict_something() is called by routines that do not repeatedly search
again, try harder in the initial search to find an object that matches
the request.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

First the routine attempted to unlock a mutex it did not own along the
error path.

Secondly the routine should never be called on any list but the inactive
one, since we attempt to unbind those objects, so fix the calling semantics.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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: NChris 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: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NEric 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: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NEric Anholt <eric@anholt.net>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.

VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.

This patch comes from Fedora rawhide kernel.
Signed-off-by: NDave Airlie <airlied@redhat.com>

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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NAndy Whitcroft <apw@canonical.com>
Cc: Eric Anholt <eric@anholt.net>
CC: stable@kernel.org
Signed-off-by: NJesse 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: NJesse 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: NJesse 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: NAnton Khirnov <wyskas@gmail.com>
Tested-by: NAnton Khirnov <wyskas@gmail.com>
Signed-off-by: NJesse 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: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NJesse 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: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJesse 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: NKenny Graunke <kenny@whitecape.org>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NOwain G. Ainsworth <oga@openbsd.org>
Signed-off-by: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NBen Gamari <bgamari.foss@gmail.com>
Signed-off-by: NJesse 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: NLi Peng <peng.li@intel.com>
Signed-off-by: NJesse 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: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJesse 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: NZhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>