From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752068AbcADTEP (ORCPT <rfc822;w@1wt.eu>);
	Mon, 4 Jan 2016 14:04:15 -0500
Received: from foss.arm.com ([217.140.101.70]:54581 "EHLO foss.arm.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751569AbcADTEN (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 4 Jan 2016 14:04:13 -0500
Date: Mon, 4 Jan 2016 19:03:53 +0000
From: Mark Rutland <mark.rutland@arm.com>
To: "Suzuki K. Poulose" <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        arm@kernel.org, punit.agrawal@arm.com, peterz@infradead.org
Subject: Re: [PATCH v5 03/11] arm-cci: Group writes to counter
Message-ID: <20160104190353.GC17127@leverpostej>
References: <1451908490-2615-1-git-send-email-suzuki.poulose@arm.com>
 <1451908490-2615-4-git-send-email-suzuki.poulose@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1451908490-2615-4-git-send-email-suzuki.poulose@arm.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, Jan 04, 2016 at 11:54:42AM +0000, Suzuki K. Poulose wrote:
> Add a helper to group the writes to PMU counter, this will be
> used to delay setting the event period to pmu::pmu_enable()
> 
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Punit Agrawal <punit.agrawal@arm.com>
> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
> ---
>  drivers/bus/arm-cci.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
> index ce0d3ef..f6b8717 100644
> --- a/drivers/bus/arm-cci.c
> +++ b/drivers/bus/arm-cci.c
> @@ -785,6 +785,21 @@ static void pmu_write_counter(struct perf_event *event, u32 value)
>  	__pmu_write_counter(cci_pmu, value, idx);
>  }
>  
> +/* Write a value to a given set of counters */
> +static void __pmu_write_counters(struct cci_pmu *cci_pmu, unsigned long *mask, u32 value)
> +{
> +	int i;
> +
> +	for_each_set_bit(i, mask, cci_pmu->num_cntrs)
> +		__pmu_write_counter(cci_pmu, value, i);
> +}

I don't understand this as-is. Why do all the counters have the same
value?

> +static void __maybe_unused
> +pmu_write_counters(struct cci_pmu *cci_pmu, unsigned long *mask, u32 value)
> +{
> +	__pmu_write_counters(cci_pmu, mask, value);
> +}

Why are these not just one function for now?

Mark.