msm: kgsl: clean up use of memdesc->hostptr

Some external memory types were using hostptr to store
a userspace virtual address, but other code assumes it is a
kernel virtual address. Make memdesc->hostpr always
be the kernel virtual address and add a useraddr
field for the userspace virtual address.

Change-Id: Id4580a2ff34aeb15f2c1b26a7134f0fd4ec52a6e
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: prevent multiple or partial mmaps of a buffer

These cases have never been a normal operation pattern of the
userspace driver. Sharing buffers through multiple mappings
is better left to dma-buf or ion.

Change-Id: I7e7658137937c96b9505d0f912dcb262d652e0c3
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: disable use of iommu TTBR1

The v1 iommu only supports splitting between TTBR0 and TTBR1
on a power of two boundary. Cutting off the userspace address
at 2G (0x80000000) is inconvienient, as the GPU userspace
address space should align with the CPU address space.

This requires changing how global allocations are managed,
since there is no longer a separate pagetable for TTBR1.
The default pagetable is still the master of these allocations
and maintains the gen_pool for allocating global addresses.
But now, these regions are mapped into each process pagetable
by calling kgsl_setup_pt(). This requires kgsl_mmu_map
and kgsl_mmu_unmap to be able to handle mapping without
virtual address allocation.

Change-Id: I94e2d63dc7e6a7ef576f993770725b6b7ba14228
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Revert "msm: kgsl: Don't hold process list global mutex in process private create"

This reverts commit 44486c64a4b60d214a43610fe341fc60d5049bc6.

Change-Id: Ic78f42c48a3259b295038e1bca05274dcd7337be