[U-Boot] [PATCH] powerpc mpc85xx: Synchronization Required for mmucsr0 spr

[Scott Wood <scottwood@freescale.com>]

On 09/07/2012 07:25 AM, Laurent Joye wrote:
> As explained in the PowerPC e500 Core Family Reference Manual
> (Synchronization Requirements for SPRs), an isync instruction
> is required after a mtspr mmucsr0 instruction.
> 
> Signed-off-by: Laurent Joye <laurent.joye@haslerrail.com>
> ---
>  arch/powerpc/cpu/mpc85xx/tlb.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/powerpc/cpu/mpc85xx/tlb.c
> b/arch/powerpc/cpu/mpc85xx/tlb.c
> index 929f6a6..c548f67 100644
> --- a/arch/powerpc/cpu/mpc85xx/tlb.c
> +++ b/arch/powerpc/cpu/mpc85xx/tlb.c
> @@ -38,6 +38,7 @@ void invalidate_tlb(u8 tlb)
>                 mtspr(MMUCSR0, 0x4);
>         if (tlb == 1)
>                 mtspr(MMUCSR0, 0x2);
> +       asm volatile("isync");
>  }
>  
>  void init_tlbs(void)
> 

We can probably just get rid of that function.  It only affects
non-IPROT entries, of which we shouldn't have any.  As of "powerpc/85xx:
clear out TLB on boot" we shouldn't have any stale TLB1 entries from
before U-Boot took over.

-Scott