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>
msm: Add null-pointer checks for domains

Add check for null-pointer before passing domain pointer
into map and unmap api to avoid null-pointer deferences.

CRs-fixed: 493503
Change-Id: I185deb9f2878ef62601eb4ca1d2b71f892ca0185
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
msm: iommu: Check for NULL genpools during domain teardown

During domain creation, some of the genpools will be set to NULL if
there is not enough memory for creation. Check for these NULL
genpools during domain destruction to avoid NULL dereferences.

Change-Id: I60238c138b809ef5c13383f5b1752ab6c799707d
CRs-Fixed: 573612
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Merge "msm: kgsl: Treat 0x0 as valid GPU pagetable physical address" into next
Merge "msm: Add null-pointer checks for domains" into next
Merge "msm: iommu: Check for NULL genpools during domain teardown" into next