Subject: Re: [PATCH 3/6] 8xx: invalidate non present TLBs

From: Benjamin Herrenschmidt <[email-masked]>
Date: Thu, 08 Oct 2009 08:18:05 +1100

On Wed, 2009-10-07 at 22:46 +0200, Joakim Tjernlund wrote:
> 8xx sometimes need to load a invalid/non-present TLBs in
> it DTLB asm handler.
> These must be invalidated separaly as linux mm don't.

not sure about the dsisr test here, what is the point ?

Cheers,
Ben.

> ---
>  arch/powerpc/mm/fault.c |    8 +++++++-
>  1 files changed, 7 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 7699394..72941c7 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -39,7 +39,7 @@
>  #include <asm/uaccess.h>
>  #include <asm/tlbflush.h>
>  #include <asm/siginfo.h>
> -
> +#include <mm/mmu_decl.h>
>  
>  #ifdef CONFIG_KPROBES
>  static inline int notify_page_fault(struct pt_regs *regs)
> @@ -243,6 +243,12 @@ good_area:
>  		goto bad_area;
>  #endif /* CONFIG_6xx */
>  #if defined(CONFIG_8xx)
> +	/* 8xx sometimes need to load a invalid/non-present TLBs.
> +	 * These must be invalidated separately as linux mm don't.
> +	 */
> +	if (error_code & 0x40000000) /* no translation? */
> +		_tlbil_va(address);
> +
>          /* The MPC8xx seems to always set 0x80000000, which is
>           * "undefined".  Of those that can be set, this is the only
>           * one which seems bad.