Re: [PATCH] mips: DEC: honor CONFIG_MIPS_FP_SUPPORT=n

From: Maciej W. Rozycki
Date: Fri Mar 04 2022 - 04:09:06 EST


On Thu, 3 Mar 2022, Randy Dunlap wrote:

> Include the DECstation interrupt handler in opting out of
> FPU support.
>
> Fixes a linker error:
>
> mips-linux-ld: arch/mips/dec/int-handler.o: in function `fpu':
> (.text+0x148): undefined reference to `handle_fpe_int'
>
> Fixes: 183b40f992c8 ("MIPS: Allow FP support to be disabled")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Cc: Paul Burton <paulburton@xxxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: "Maciej W. Rozycki" <macro@xxxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxxx
> ---
> This builds OK. Is it enough for runtime interrupt handling?

There's:

#ifdef CONFIG_32BIT
lw t2,cpu_fpu_mask
#endif

earlier on that needs to go too, and code in arch/mips/dec/setup.c below:

/* Register board interrupts: FPU and cascade. */

(we don't want an unhandled interrupt unmasked). Are you happy to do such
an update or shall I?

I cannot verify that change at run time, because any program that does FP
will then crash. Maybe init(8) and sulogin(8) won't. I can check that.

Thanks for doing this stuff!

Maciej