Subject: Re: [PATCH] powerpc/oprofile: Fix error in oprofile power7_marked_instr_event() function

From: Benjamin Herrenschmidt <[email-masked]>
Date: Fri, 04 Jan 2013 15:37:07 +1100

On Thu, 2012-11-29 at 08:42 -0800, Carl E. Love wrote:
> Ben:
> 
> Please review the following patch.  If it is acceptable, will you please
> commit it to the mainline tree.  Thanks.
> 
>               Carl Love
> 
> P.S.  Looks like I sent it to the wrong mailing list the first time to
> get it into the patch queue.

Also avoid my Notes address for patches please...

> --------------------------------------------------------------------------
> powerpc/oprofile: Fix error in oprofile power7_marked_instr_event() function
> 
> The calculation for the left shift of the mask OPROFILE_PM_PMCSEL_MSK has an
> error.  The calculation is should be to shift left by (max_cntrs - cntr) times
> the width of the pmsel field width.  However, the #define OPROFILE_MAX_PMC_NUM
> was used instead of OPROFILE_PMSEL_FIELD_WIDTH.  This patch fixes the
> calculation.

Paul, Anton, can of you ack this ?

Cheers,
Ben.

> Signed-off-by: Carl Love <[email-masked]>
> ---
>  arch/powerpc/oprofile/op_model_power4.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c
> index 315f949..f444b94 100644
> --- a/arch/powerpc/oprofile/op_model_power4.c
> +++ b/arch/powerpc/oprofile/op_model_power4.c
> @@ -52,7 +52,7 @@ static int power7_marked_instr_event(u64 mmcr1)
>  	for (pmc = 0; pmc < 4; pmc++) {
>  		psel = mmcr1 & (OPROFILE_PM_PMCSEL_MSK
>  				<< (OPROFILE_MAX_PMC_NUM - pmc)
> -				* OPROFILE_MAX_PMC_NUM);
> +				* OPROFILE_PMSEL_FIELD_WIDTH);
>  		psel = (psel >> ((OPROFILE_MAX_PMC_NUM - pmc)
>  				 * OPROFILE_PMSEL_FIELD_WIDTH)) & ~1ULL;
>  		unit = mmcr1 & (OPROFILE_PM_UNIT_MSK