All of the regular CPU init path needs to be __cpuinit annotated for CPU
hotplug.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

This does a detect_cpu_and_cache_system() -> cpu_probe() rename, tidies
up the unused return value, and stuffs it under __cpuinit in preparation
for CPU hotplug.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

vmemmap and the vmsplit code amongst others need to be able to take page
faults much earlier than trap_init() time, so move this in to the early
CPU initialization. VBR setup for secondary CPUs is already handled
through start_secondary(), so we only need to do this for the boot CPU.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

The old ctrl in/out routines are non-portable and unsuitable for
cross-platform use. While drivers/sh has already been sanitized, there
is still quite a lot of code that is not. This converts the arch/sh/ bits
over, which permits us to flag the routines as deprecated whilst still
building with -Werror for the architecture code, and to ensure that
future users are not added.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Now that cached_to_uncached works as advertized in 32-bit mode and we're
never going to be able to map < 16MB anyways, there's no need for the
special uncached section. Kill it off.

Signed-off-by: Paul 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The fpu_init() register initialization has been replaced by xstate setup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: Paul Mundt <lethal@linux-sh.org>

Nothing is using these now, so kill them all off.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Now that associative cache writes are no longer needed by the SH-4/SH-4A
cache flush code, associative write support can be explicitly disabled
for all SH-4A parts. This makes any associative write throw an exception,
as this behaviour can not be assumed to exist on future parts.

Signed-off-by: Paul 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: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>