[v2 2/2] [PowerPC] Allow use of SIMD in interrupts from kernel code

[Russell Currey]

On Mon, 2019-05-13 at 23:23 -0300, Shawn Landden wrote:
> This second patch is separate because it could be wrong,
> like I am not sure about how kernel thread migration works,
> and it is even allowing simd in preemptible kernel code.
> 
> Signed-off-by: Shawn Landden <shawn at git.icu>
> ---

Hi Shawn,

This patch doesn't build on 64-bit embedded (ppc64e_defconfig):

arch/powerpc/kernel/process.c:194:13: error: 'interrupted_kernel_fpu_idle' defined but not used [-Werror=unused-function]
 static bool interrupted_kernel_fpu_idle(void)
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~

and otherwise adds two sparse warnings:

+arch/powerpc/kernel/process.c:356:13: warning: function 'disable_kernel_altivec' with external linkage has definition
+arch/powerpc/kernel/process.c:416:6: warning: symbol 'may_use_simd' was not declared. Should it be static?

There's also some style issues (spaces instead of tabs).

Reported by snowpatch (see https://patchwork.ozlabs.org/patch/1099181/)

- Russell