With this change, every batchbuffer can use all available fences (save
pinned and scanout, of course) without ever stalling the gpu!

In theory. Currently the actual pipelined update of the register is
disabled due to some stability issues. However, just the deferred update
is a significant win.

Based on a series of patches by Daniel Vetter.

The premise is that before every access to a buffer through the GTT we
have to declare whether we need a register or not. If the access is by
the GPU, a pipelined update to the register is made via the ringbuffer,
and we track the last seqno of the batches that access it. If by the
CPU we wait for the last GPU access and update the register (either
to clear or to set it for the current buffer).

One advantage of being able to pipeline changes is that we can defer the
actual updating of the fence register until we first need to access the
object through the GTT, i.e. we can eliminate the stall on set_tiling.
This is important as the userspace bo cache does not track the tiling
status of active buffers which generate frequent stalls on gen3 when
enabling tiling for an already bound buffer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

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

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

This makes the various rings more consistent by removing the anomalous
handing of the rendering ring execbuffer dispatch.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

... so that upon first use after resume we will reacquire the fence reg.
Reported-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

As the error occurred on the current object, it means that its state was
not changed and so it should be excluded from the unwind.
Reported-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

We don't track gpu flush request in any special way. So even with
obj->write_domain == 0, a gpu flush might be outstanding but no
yet executed. Even worse, the latest request might use the object
only for reading. So and unconditional call to object_wait_rendering
is needed for !pipelined.

Hence revert that patch fully and untangle the flushing from the
synchronization again.
Reported-by: NKeith Packard <keithp@keithp.com>
Tested-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Besides the minimal improvement in reducing the execbuffer overhead, the
real benefit is clarifying a few routines.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

A number of dragons have been seen lurking within the execbuffer code.
The first step is then to isolate them from the rest and begin to
scrutinise them in depth. Suggested by Daniel Vetter.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Simply remove our accounting of objects inside the aperture, keeping
only track of what is in the aperture and its current usage. This
removes the over-complication of BUGs that were attempting to keep the
accounting correct and also removes the overhead of the accounting on
the hot-paths.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... to benefit from the compiler checking that we remember to handle
and propagate errors.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

With KMS, we can simply relinquish the fence when we idle the GPU and
reassign it upon first use.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Not employed just yet...
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Commit d09c23de intended to add a 30ms delay to give the ADD time to
detect any TVs connected. However, it used the sdvo->is_tv flag to do so
which is dependent upon the previous detection result and not whether the
output supports TVs.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

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

Avoid evicting buffers that will be used later in the batch in order to
make room for the initial buffers by pinning all bound buffers in a
single pass before binding (and evicting for) fresh buffer.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

On a few devices, like the Mac Mini, the CRT DDC pins are shared between
the analog connector and the digital connector. In this scenario, rely
on the EDID to determine if a digital panel is connected to the digital
connector.
Reported-and-tested-by: NTino Keitel <tino.keitel@tikei.de>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

... reduce the frequency of checking to further reduce the wakeups and
CPU overhead.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This used to check the precondition that all fences were to be located
in a mappable area, redundant now as those two parameters are combined
into one.

After pinning, we assert that the buffer is bound into the desired
region.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

The pipe control object is allocated by the device for the sole use of the
render ringbuffer. Move this detail from the general code to the render
ring buffer initialisation.
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>

Combining map_and_fenceable revealed a bug in
i915_gem_object_gtt_size() in that it always computed the appropriate
fence size for the object regardless of tiling state which caused us to
over-allocate linear buffers when binding to the GTT.
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: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

No more drm_*_agp in i915_gem.c!
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This still uses the agp functions to actually reinstate the mappings
(with a gross hack to make agp cooperate), but it wires everything
up correctly for the switchover.

The call to agp_rebind_memory can be dropped because all non-kms drivers
do all their rebinding on EnterVT.

v2: Be more paranoid and flush the chipset cache after restoring gtt
mappings.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

This is required to restore gtt mappings on resume when agp is gone.

The right way to do this would be to make sturct drm_mm_node embeddable
and use the allocation list maintained by the drm memory manager. But
that's a bigger project. Getting rid of the per bo agp_mem will save
more memory than this wastes, anyway.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

... and a few other defines.
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

Currently if we hit a pagefault when applying a user relocation for the
execbuffer, we bail and return EFAULT to the application. Instead, we
need to unwind, drop the dev->struct_mutex, copy all the relocation
entries to a vmalloc array (to avoid any potential circular deadlocks
when resolving the pagefault), retake the mutex and then apply the
relocations.  Afterwards, we need to again drop the lock and copy the
vmalloc array back to userspace.

v2: Incorporate feedback from Daniel Vetter.
Reported-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... and no need to perform a linear search for the index.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

The GATT is a write-only set of registers, reading from them in the
manner of i915_gtt_to_phys() is supposed to be undefined. However a
simple solution exists as we allocate linear memory from the stolen
area, we can simply add the block offset to the base register. As a
side-effect we recover all the unused stolen GTT entries and so enlarge
our aperture.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

After a GPU reset, the backlight controller registers may be also reset
to 0. In that case we should restore those to the original values
programmed by the BIOS. Note that we still lack the code to handle the
case where the BIOS failed to program those registers at all...
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>

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

As we conflated intel_sdvo->is_hdmi with both having HDMI support on the
ADD along with having HDMI support on the monitor, we would attempt to
use HDMI encodings even if the interface did not support those commands.
Reported-by: NSimon Farnsworth <simon.farnsworth@onelan.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Tested-by: NSimon Farnsworth <simon.farnsworth@onelan.co.uk>
Reviewed-by: NSimon Farnsworth <simon.farnsworth@onelan.co.uk>

We were reading our 64-bit value in I915_READ64 and returning 32 bits
of it.  The restoration of fence regs at resume then had a zero end
value, and the fence had no effect.

Version 2: Split register access functions into per-size versions

Sharing code between different sizes seemed reasonable when we only
needed a single copy, but as 64-bit access requires its own version,
it makes sense to just split them out for each size.
Reported-by: NPeter Clifton <pcjc2@cam.ac.uk>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NKeith Packard <keithp@keithp.com>
[ickle: use a macro to create the various read/write routines]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>