Convert some of the global flush users over to using the local variants
that don't need to use the global routines.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Rename the existing flush routines to local_ variants for use by
the IPI-backed global flush routines on SMP.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Previously this was implemented using a global cache, cache
this per-CPU instead and bump up the number of context IDs to
match NR_CPUS.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Only SH-4 needs to set _PAGE_WT when using write-through caching,
don't attempt to set it on SH-3 where it ends up being a reserved
bit.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This converts the lazy dcache handling to the model described in
Documentation/cachetlb.txt and drops the ptep_get_and_clear() hacks
used for the aliasing dcaches on SH-4 and SH7705 in 32kB mode. As a
bonus, this slightly cuts down on the cache flushing frequency.

With that and the PTEA handling out of the way, the update_mmu_cache()
implementations can be consolidated, and we no longer have to worry
about which configuration the cache is in for the SH7705 case.

And finally, explicitly disable the lazy writeback on SMP (SH-4A).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements initial support for the vsyscall page on SH.
At the moment we leave it configurable due to having nommu
to support from the same code base. We hook it up for the
signal trampoline return at present, with more to be added
later, once uClibc catches up.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Cleanup of page table allocators, using generic folded PMD and PUD
helpers. TLB flushing operations are moved to a more sensible spot.

The page fault handler is also optimized slightly, we no longer waste
cycles on IRQ disabling for flushing of the page from the ITLB, since
we're already under CLI protection by the initial exception handler.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>