Separate ib parse checking from cffdump as it is useful
in other situations. This is controlled by a new debugfs
file, ib_check. All ib checking is off (0) by default,
because parsing and mem_entry lookup can have a performance
impact on some benchmarks. Level 1 checking verifies the
IB1's. Level 2 checking also verifies the IB2.
kmalloc allocates physically contiguous memory and
may fail for larger allocations due to fragmentation.
The large allocations are caused by the fact that the
scatterlist structure is 24 bytes and the array size
is proportional to the number of pages being mapped.
The tools that process cff dumps expect a linear
memory region, but the start address of that region can
be configured. As long as there is only a single
pagetable (so that there aren't duplicate virtual
addresses in the dump), dumps captured with the
mmu on are easier to deal with than reconfiguring
to turn the mmu off.
Some hangs are fooling the postmortem dump code into
running off the end of a buffer. Fix this by making
its bounds check logic work better by reusing the
logic from kgsl_find_region().
