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>

Found by the new strict checking for the mutex being held whilst
manipulating the forcewake status.
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>

Moved the macros around to properly do reads and writes for the given
GPU. This is to address special requirements for gen6 (SNB) reads and
writes.

Registers in the range 0-0x40000 on gen6 platforms require special
handling. Instead of relying on the callers to pick the registers
correctly, move the logic into the read and write functions.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

If the outputs are active and continuing to access the GATT when we
teardown the PTEs, then there is a potential for us to hang the GPU.
The hang tends to be a PGTBL_ER with either an invalid host access or
an invalid display plane fetch.

v2: Reorder IRQ initialisation to defer until after GEM is setup.
Reported-by: NPekka Enberg <penberg@kernel.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: Daniel Vetter <daniel.vetter@ffwll.ch> (855GM)
Tested-by: NPekka Enberg <penberg@kernel.org>
           # note that this doesn't fix the underlying problem of the
             PGTBL_ER and pipe underruns being reported immediately upon
             init on his 965GM MacBook
Reported-and-tested-by: NRick Bramley <richard.bramley@hp.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35635Reported-and-tested-by: NZdenek Kabelac <zdenek.kabelac@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36048Reviewed-by: NBen Widawsky <ben@bwidawsk.net>

Rely on the GPU snooping into the CPU cache for appropriately bound
objects on MI_FLUSH. Or perhaps one day we will have a cache-coherent
CPU/GPU package...
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>

... 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>

Currently this is only useful for the rc6 stuff. But this would also be
useful when I finally get around to the logical context + ppgtt stuff.
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>

For debug & testing.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

There is a race condition between setting PWRCTXA and executing
MI_SET_CONTEXT. PWRCTXA must not be set until a valid context has been
written (or else the GPU could possible go into rc6, and return to an
invalid context).
Reported-and-Tested-by: NGu Rui <chaos.proton@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28582Signed-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>

Added a new function which waits for the ringbuffer space to be equal to
(total - 8). This is the empty condition of the ringbuffer, and
equivalent to head==tail.

Also modified two users of this functionality elsewhere in the code.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

In the failure cases during rc6 initialization, both the power context
and render context may get !refcount without holding struct_mutex.
However, on rc6 disabling, the lock is held by the caller.

Rearranged the locking so that it's safe in both cases.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NKeith Packard <keithp@keithp.com>

They're used in one place, and not providing any descriptive value,
with their names just being approximately the conjunction of the
struct name and the struct field.

This diff was produced with gcc -E, copying the new struct definitions
out, moving a couple of the old comments into place in the new
structs, and reindenting.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We used to have these from the product of (pch, non-pch) * (pipe a,
pipe b).  Now we can just use the nice per-pipe reg macros in the
split out crtc_mode_sets.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Ironlake is where the PCH split started.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

While g4x had DP, eDP came with Ironlake, so we don't need that code here.
Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NEric Anholt <eric@anholt.net>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This path, which shouldn't be *that* complicated, is now so littered
with per-chipset tweaks that it's hard to trace the order of what
happens.  HAS_PCH_SPLIT() is the most radical change across chipsets,
so it seems like a natural split to simplify the code.

This first commit just copies the existing code without changing
anything.

v2: updated to track removal of call to intel_enable_plane from i9xx_crtc_mode_set
Signed-off-by: NEric Anholt <eric@anholt.net>
Hella-acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We need to ensure that we feed valid memory into the display plane
attached to the pipe when switching the pipe on. Otherwise, the display
engine may read through an invalid PTE and so throw an PGTBL_ER
exception.

As we need to perform load detection before even the first object is
allocated for the fbdev, there is no pre-existing object large enough
for us to borrow to use as the framebuffer. So we need to create one
and cleanup afterwards. At other times, the current fbcon may be large
enough for us to borrow it for duration of load detection.

Found by assert_fb_bound_for_plane().
Reported-by: NKnut Petersen <Knut_Petersen@t-online.de>
References: https://bugs.freedesktop.org/show_bug.cgi?id=36246Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NKeith Packard <keithp@keithp.com>

As we now never attempt to steal a crtc for load detection, we either
set a mode on a new pipe, or change the dpms mode on an existing pipe.
Never both, so we can simplify the code slightly.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NKeith Packard <keithp@keithp.com>

As we only allow the use of a disabled CRTC, we don't need to handle the
case where we are reusing an already enabled pipe.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NKeith Packard <keithp@keithp.com>

... and the no longer relevant comment. The code ceased stealing a pipe
for load detection a long time ago.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Keep all the state required for undoing and restoring the previous pipe
configuration together in a single struct passed from
intel_get_load_detect_pipe() to intel_release_load_detect_pipe() rather
than stuffing them inside the common encoder structure.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Check the return value from drm_crtc_set_mode(), report the failure
via a debug message and propagate the error back to the caller. This
prevents us from blissfully continuing to do the load detection on a
disabled pipe. Fortunately actual failure for modesetting is very rare,
and reported failures even rarer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NKeith Packard <keithp@keithp.com>

... and so remove the confusion as to whether to use the returned crtc
or intel_encoder->base.crtc with the subsequent load-detection. Even
though they were the same, the two instances of load-detection code
disagreed over which was the more correct.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
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>

If we're using vga switcheroo, the device may be turned off
and poking it can return random state. This provokes an OOPS fixed
separately by 8ff887c847 (drm/i915/dp: Be paranoid in case we disable a
DP before it is attached). Trying to use and respond to events on a
device that has been turned off by the user is in principle a silly thing
to do.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: NKeith Packard <keithp@keithp.com>

Despite the fixes in 548f245b (drm/i915: fix per-pipe reads after
"cleanup"), we missed one neighbouring read that was mistakenly replaced
with the reg value in 9db4a9c7 (drm/i915: cleanup per-pipe reg usage).
This was preventing us from correctly determining the mode the BIOS left
the panel in for machines that neither have an OpRegion nor access to
the VBT, (e.g. the EeePC 700).
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>

When enabling the plane, it is helpful to have already pointed that
plane to valid memory or else we may incur the wrath of a PGTBL_ER.
This code preserved the behaviour from the bad old days for unknown
reasons...

Found by assert_fb_bound_for_plane().

References: https://bugs.freedesktop.org/show_bug.cgi?id=36246Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>

Given that the hardware may be left in a random condition by the BIOS,
it is conceivable that we then attempt to clear the DP_PIPEB_SELECT bit
without us ever enabling/attaching the DP encoder to a pipe. Thus
causing a NULL deference when we attempt to wait for a vblank on that
crtc.
Reported-and-tested-by: NBryan Christ <bryan.christ@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36314Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36456Reported-and-tested-by: NBo Wang <bo.b.wang@intel.com>
Cc: stable@kernel.org
Signed-off-by: NKeith Packard <keithp@keithp.com>

Reported-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: NKeith Packard <keithp@keithp.com>

Out of the entire GART/VM subsystem, the hw designers changed
the location of 3 regs.

v2: airlied: add parameter for userspace to work from.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

This is the least-bad behaviour.  It means that we signal the
vblank event before it actually happens, but since we're disabling
vblanks there's no guarantee that it will *ever* happen otherwise.

This prevents GL applications which use WaitMSC from hanging
indefinitely.
Signed-off-by: NChristopher James Halse Rogers <christopher.halse.rogers@canonical.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Since fafcf94e introduced an edid size, it seems to have broken this path.

This manifest as oops on T500 Lenovo laptops with dual graphics primarily.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33812

cc: stable@kernel.org
Reviewed-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

i915 calls the panic handler function on last close to reset the modes,
however this is a really bad idea for multi-gpu machines, esp shareable
gpus machines. So add a new entry point for the driver to just restore
its own fbcon mode.

v2: move code into fb helper, fix panic code to block mode change on
powered off GPUs.

[airlied: this hits drm core and I wrote it and it was reviewed on intel-gfx
 so really I signed it off twice ;-).]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

needed by mesa for htile setup.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>