Re: [PATCH 6/8] 8xx: Add missing Guarded setting in DTLB Error.

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sun, 2009-10-11 at 18:35 +0200, Joakim Tjernlund wrote:
> only DTLB Miss did set this bit, DTLB Error needs too otherwise
> the setting is lost when the page becomes dirty.

Easier fix: Stop doing thing in DTLB Error

Ben.

> --
>  arch/powerpc/kernel/head_8xx.S |   13 ++++++++++---
>  1 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
> index 027856e..371b606 100644
> --- a/arch/powerpc/kernel/head_8xx.S
> +++ b/arch/powerpc/kernel/head_8xx.S
> @@ -552,9 +552,16 @@ DARFix:	/* Return from dcbx instruction bug workaround, r10 holds value of DAR *
>  	 */
>  	ori	r11, r11, 1		/* Set valid bit in physical L2 page */
>  	DO_8xx_CPU6(0x3b80, r3)
> -	mtspr	SPRN_MD_TWC, r11		/* Load pte table base address */
> -	mfspr	r11, SPRN_MD_TWC		/* ....and get the pte address */
> -	lwz	r10, 0(r11)		/* Get the pte */
> +	mtspr	SPRN_MD_TWC, r11	/* Load pte table base address */
> +	mfspr	r10, SPRN_MD_TWC	/* ....and get the pte address */
> +	lwz	r10, 0(r10)		/* Get the pte */
> +	/* Insert the Guarded flag into the TWC from the Linux PTE.
> +	 * It is bit 27 of both the Linux PTE and the TWC
> +	 */
> +	rlwimi	r11, r10, 0, 27, 27
> +	DO_8xx_CPU6(0x3b80, r3)
> +	mtspr	SPRN_MD_TWC, r11
> +	mfspr	r11, SPRN_MD_TWC	/* get the pte address again */
>  
>  	ori	r10, r10, _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_HWWRITE
>  	stw	r10, 0(r11)		/* and update pte in table */