The render P-state handling code requires reading from a GT register.
This means that FORCEWAKE must be written to, a resource which is shared
and should be protected by struct_mutex. Hence we can not manipulate
that register from within the interrupt handling and so must delegate
the task to a workqueue.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Provide a reference count to track the forcewake state of the GPU and
give a safe mechanism for userspace to wake the GT. This also potentially
saves a UC read if the GT is known to be awake already.

The reference count is atomic, but the register access and hardware wake
sequence is protected by struct_mutex.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... to clarify just how we use it inside the driver and remove the
confusion of the poorly matching agp_type names. We still need to
translate through agp_type for interface into the fake AGP driver.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Required so that we don't obliterate the queue if initialising the
rings after the global IRQ handler is installed.

[Jesse, you recently looked at refactoring the IRQ installation
routines, does moving the initialisation of ring buffer data structures away
from that routine make sense in your grand scheme?]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NKeith Packard <keithp@keithp.com>

I stumbled over this magic bit in the gen3 INSTPM:

Bit11 Interrupt-Based AGPBUSY# Enable:

‘0’ = Pending GMCH interrupts will not cause AGPBUSY# assertion.
‘1’ = Pending GMCH interrupts will cause AGPBUSY# assertion and hence
      can cause the CPU to exit C3.  There is no suppression of cacheable
      writes.

Note that in either case in C3 the interrupts are not lost. They will be
forwarded to the ICH when the GMCH is out of C3.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@kernel.org

Using PM latency request turns out to be very fragile and only works for
some systems, depending upon the ACPI implementation. However, I've
stumbled across a promising bit in INSTPM: "Interrupt-Based AGPBUSY#".

This reverts commit b0b544cd.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_irq.c: In function ‘ironlake_irq_postinstall’:
drivers/gpu/drm/i915/i915_irq.c:1618: warning: unused variable ‘pipe’
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We can enable some safely, but FDI and transcoder interrupts can occur
and block other interrupts from being detected (like port hotplug
events).  So keep them disabled by default (they can be re-enabled for
debugging display bringup, but should generally be off).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We can enable some safely, but FDI and transcoder interrupts can occur
and block other interrupts from being detected (like port hotplug
events).  So keep them disabled by default (they can be re-enabled for
debugging display bringup, but should generally be off).
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We had some conversions over to the _PIPE macros, but didn't get
everything.  So hide the per-pipe regs with an _ (still used in a few
places for legacy) and add a few _PIPE based macros, then make sure
everyone uses them.

[update: remove usage of non-existent no-op macro]
[update 2: keep modesetting suspend/resume code, update to new reg names]
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
[ickle: stylistic cleanups for checkpatch and taste]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

A lot of minor tweaks to fix the tracepoints, improve the outputting for
ftrace, and to generally make the tracepoints useful again. It is a start
and enough to begin identifying performance issues and gaps in our
coverage.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

Hugh Dickins found that characters in xterm were going missing and oft
delayed. Being the curious type, he managed to associate this with the
new high-precision vblank patches; disabling these he found, restored
the orderliness of his characters.

The oddness begins when one realised that Hugh was not using vblanks at
all on his system (fvwm and some xterms). Instead, all he had to go on
were warning of a pipe underrun, curiously enough at around 60Hz. He
poked and found that in addition to the underrun warning, the hardware
was flagging the start of a new frame, a vblank, which in turn was
kicking off the pending vblank processing code.

There is little we can do for the underruns on Hugh's machine, a
Crestline [965GM], which must have its FIFO watermarks set to 8.
However, we do not need to process the vblank if we know that they are
disabled...
Reported-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

error_bo and pinned_bo could be used uninitialised if there were no
active buffers.

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

If the driver calls into the kernel to wait for a breadcrumb to pass,
but hasn't enabled interrupts, fallback to polling the breadcrumb value.
Reported-by: NChris Clayton <chris2553@googlemail.com>
Tested-by: NChris Clayton <chris2553@googlemail.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Reported-by: NChris Clayton <chris2553@googlemail.com>
Tested-by: NChris Clayton <chris2553@googlemail.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

Hangcheck and error recovery is only used by GEM.
Reported-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

945 class hardware has an interesting quirk in which the vblank
interrupt is not raised if the CPU is in a low power state. (We also
suspect that the memory bus is clocked to the CPU/c-state and not the
GPU so there are secondary starvation issues.) In order to prevent the
most obvious issue of the low of the vblank interrupt (stuttering
compositing that only updates when the mouse is moving) is to install a
PM QoS request to prevent low c-states whilst the GPU is active.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Whilst we had no older batches on the active list, everything was fine.
However, if the GPU is free running and the requests are only being
reaped by the periodic retirer, than the current seqno may not be at the
start of the list. In this case we need to select the first batch after
the last seqno written by the gpu and not inclusive of the seqno.
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>

FDI and the transcoders can fail for various reasons, so detect those
conditions and report on them.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

Otherwise we may consume 20% of the CPU just handling IRQs whilst
rendering. Ouch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Add an interrupt handler for switching graphics frequencies and handling
PM interrupts.  This should allow for increased performance when busy
and lower power consumption when idle.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

v2: Change IS_IRONLAKE to IS_GEN5 to adapt to 2.6.37

This patch adds new functions for use by the drm core:

.get_vblank_timestamp() provides a precise timestamp
for the end of the most recent (or current) vblank
interval of a given crtc, as needed for the DRI2
implementation of the OML_sync_control extension.
It is a thin wrapper around the drm function
drm_calc_vbltimestamp_from_scanoutpos() which does
almost all the work.

.get_scanout_position() provides the current horizontal
and vertical video scanout position and "in vblank"
status of a given crtc, as needed by the drm for use by
drm_calc_vbltimestamp_from_scanoutpos().

The patch modifies the pageflip completion routine
to use these precise vblank timestamps as the timestamps
for pageflip completion events.

This code has been only tested on a HP-Mini Netbook with
Atom processor and Intel 945GME gpu. The codepath for
(IS_G4X(dev) || IS_GEN5(dev) || IS_GEN6(dev)) gpu's
has not been tested so far due to lack of hardware.
Signed-off-by: NMario Kleiner <mario.kleiner@tuebingen.mpg.de>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Restore PIPE_CONTROL once again just for Ironlake, as it appears that
MI_USER_INTERRUPT does not have the same coherency guarantees, that is
on Ironlake the interrupt following a GPU write is not guaranteed to
arrive after the write is coherent from the CPU, as it does on the
other generations.
Reported-by: NZhenyu Wang <zhenyuw@linux.intel.com>
Reported-by: NShuang He <shuang.he@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32402Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In order to enforce the correct memory barriers for irq get/put, we need
to perform the actual counting using atomic operations.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The workaround is hideous and we are using the STORE_DWORD on all other
generations on all other rings, so use for the gen5 render ring as
well.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The bulk of the change is to convert the growing list of rings into an
array so that the relationship between the rings and the semaphore sync
registers can be easily computed.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

Having seen the effects of erroneous fencing on the batchbuffer, a
useful sanity check is to record the fence registers at the time of an
error.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

A glorified s/obj_priv/obj/ with a net reduction of over a 100 lines and
many characters!
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

When trying to diagnose mysterious errors on resume, capture the
display register contents as well.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The pinned buffers are useful for diagnosing errors in setting up state
for the chipset, which may not necessarily be 'active' at the time of
the error, e.g. the cursor buffer object.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... and so hide the flushes from tracing.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We only ever used the PRB0, neglecting the secondary ring buffers, and
now with the advent of multiple engines with separate ring buffers we
need to excise the anachronisms from our code (and be explicit about
which ring we mean where). This is doubly important in light of the
FORCEWAKE required to read ring buffer registers on SandyBridge.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>