This plugs in the alignment and emulation fault reporting for perf sw
events.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This follows the x86 xstate changes and implements a task_xstate slab
cache that is dynamically sized to match one of hard FP/soft FP/FPU-less.

This also tidies up and consolidates some of the SH-2A/SH-4 FPU
fragmentation. Now fpu state restorers are commonly defined, with the
init_fpu()/fpu_init() mess reworked to follow the x86 convention.
The fpu_init() register initialization has been replaced by xstate setup
followed by writing out to hardware via the standard restore path.

As init_fpu() now performs a slab allocation a secondary lighterweight
restorer is also introduced for the context switch.

In the future the DSP state will be rolled in here, too.

More work remains for math emulation and the SH-5 FPU, which presently
uses its own special (UP-only) interfaces.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

A number of small optimisations to FPU handling, in particular:

 - move the task USEDFPU flag from the thread_info flags field (which
   is accessed asynchronously to the thread) to a new status field,
   which is only accessed by the thread itself. This allows locking to
   be removed in most cases, or can be reduced to a preempt_lock().
   This mimics the i386 behaviour.

 - move the modification of regs->sr and thread_info->status flags out
   of save_fpu() to __unlazy_fpu(). This gives the compiler a better
   chance to optimise things, as well as making save_fpu() symmetrical
   with restore_fpu() and init_fpu().

 - implement prepare_to_copy(), so that when creating a thread, we can
   unlazy the FPU prior to copying the thread data structures.

Also make sure that the FPU is disabled while in the kernel, in
particular while booting, and for newly created kernel threads,

In a very artificial benchmark, the execution time for 2500000
context switches was reduced from 50 to 45 seconds.
Signed-off-by: NStuart Menefy <stuart.menefy@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

math-emu wasn't converted for the trap_no/errno_code changes,
get it building again.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Spelling fixes in arch/sh/.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

A few of these managed to sneak back in, get rid of them once
and for all.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements initial math-emu support, aimed primarily at SH-3.
Signed-off-by: NTakashi YOSHII <takasi-y@ops.dti.ne.jp>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>