msm: kgsl: Allow GPU start to run in a high priority queue

The GPU start sequence needs to run with low latency when coming
out of slumber for the first draw command. For those cases allow the
start function to be queued into a high priority workqueue to reduce
the chance of it getting scheduled out.

Change-Id: Ic0dedbada7ef4d63b54e826862fbefdfb71a092a
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: Add an input handler to power up the GPU on a touch event

On a device where the primary input is a touchscreen nobody is
surprised that touch events are often the catalyst for drawing
frames. If the GPU is in slumber we can get a jump on the action
by watching for touch events and turning the GPU on in anticipation
of a draw call. Register for events from all input drivers
returning EV_ABS events and queue a work task to power up the GPU
if it is currently in slumber.

Change-Id: Ic0dedbadbdc96ef9ddd78252ea65f8e1cdd00110
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: Mark the IOMMU setstate memory as read only

Mark the IOMMU setstate memory as read only in the pagetable.

Change-Id: Ic0dedbadb19e499c749cd744c3e89be3bcb4c2a2
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: Treat 0x0 as valid GPU pagetable physical address

Iommu driver could be allocating a valid GPU pagetable at
physical address 0x0, remove assumption from GPU kernel driver
that 0x0 is invalid pagetable address.

Change-Id: I213c0fbc1d90a13bef83c7d7589ad9e5729771fd
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>