msm: scm: Add scm_call_noalloc and helper macros

Currently, scm_call internally calls kmalloc() to allocate a command
buffer structure. This prevents scm_call from working before kmalloc
structures are initialized or during atomic contexts. Allow clients
to pass in a pre-allocated buffer for scm_call to be used for internal
structures.

Change-Id: Id09500c8c696298228aefdcc2a61953e654677c9
CRs-Fixed: 498392
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Readahead: Optimize divide/multiply by power of 2 using L/R shift
hashtable: introduce a small and naive hashtable

This hashtable implementation is using hlist buckets to provide a simple
hashtable to prevent it from getting reimplemented all over the kernel.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
[ Merging this now, so that subsystems can start applying Sasha's
  patches that use this   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
block,elevator: use new hashtable implementation

Switch elevator to use the new hashtable implementation. This reduces the
amount of generic unrelated code in the elevator.

This also removes the dymanic allocation of the hash table. The size of the table is
constant so there's no point in paying the price of an extra dereference when accessing
it.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>