Subject: Re: [PATCH] powerpc: don't flush/invalidate the d/icache for an unknown relocation type

From: "Suzuki K. Poulose" <[email-masked]>
Date: Thu, 27 Jun 2013 12:06:33 +0530

On 06/27/2013 06:39 AM, Kevin Hao wrote:
> For an unknown relocation type since the value of r4 is just the 8bit
> relocation type, the sum of r4 and r7 may yield an invalid memory
> address. For example:
>      In normal case:
>               r4 = c00xxxxx
>               r7 = 40000000
>               r4 + r7 = 000xxxxx
>
>      For an unknown relocation type:
>               r4 = 000000xx
>               r7 = 40000000
>               r4 + r7 = 400000xx
>     400000xx is an invalid memory address for a board which has just
>     512M memory.
>
> And for operations such as dcbst or icbi may cause bus error for an
> invalid memory address on some platforms and then cause the board
> reset. So we should skip the flush/invalidate the d/icache for
> an unknown relocation type.
>

Good catch. Thanks for the fix.

Acked-by: Suzuki K. Poulose <[email-masked]>