[SPARC64]: Add infrastructure for dynamic TSB sizing.

This also cleans up tsb_context_switch().  The assembler
routine is now __tsb_context_switch() and the former is
an inline function that picks out the bits from the mm_struct
and passes it into the assembler code as arguments.

setup_tsb_parms() computes the locked TLB entry to map the
TSB.  Later when we support using the physical address quad
load instructions of Cheetah+ and later, we'll simply use
the physical address for the TSB register value and set
the map virtual and PTE both to zero.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/process.c

@@ -441,8 +441,7 @@ void flush_thread(void)
 
 	mm = t->task->mm;
 	if (mm)
-		tsb_context_switch(__pa(mm->pgd),
-				   mm->context.sparc64_tsb);
+		tsb_context_switch(mm);
 
 	set_thread_wsaved(0);