From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759475AbcAKK6t (ORCPT ); Mon, 11 Jan 2016 05:58:49 -0500 Received: from foss.arm.com ([217.140.101.70]:54321 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757609AbcAKK6s (ORCPT ); Mon, 11 Jan 2016 05:58:48 -0500 Subject: Re: [PATCH v5 07/11] arm-cci: Add routines to save/restore all counters To: Mark Rutland References: <1451908490-2615-1-git-send-email-suzuki.poulose@arm.com> <1451908490-2615-8-git-send-email-suzuki.poulose@arm.com> <20160111105006.GF6499@leverpostej> Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, arm@kernel.org, punit.agrawal@arm.com, peterz@infradead.org From: "Suzuki K. Poulose" Message-ID: <56938AE5.9090702@arm.com> Date: Mon, 11 Jan 2016 10:58:45 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20160111105006.GF6499@leverpostej> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/01/16 10:50, Mark Rutland wrote: > On Mon, Jan 04, 2016 at 11:54:46AM +0000, Suzuki K. Poulose wrote: >> Adds helper routines to disable the counter controls for >> all the counters on the CCI PMU and restore it back, by >> preserving the original state in caller provided mask. >> >> Cc: Punit Agrawal >> Cc: Mark Rutland >> Signed-off-by: Suzuki K. Poulose >> --- >> drivers/bus/arm-cci.c | 38 ++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 38 insertions(+) >> >> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c >> index a3938ef..2f1fcf0 100644 >> --- a/drivers/bus/arm-cci.c >> +++ b/drivers/bus/arm-cci.c >> @@ -672,6 +672,44 @@ static void pmu_set_event(struct cci_pmu *cci_pmu, int idx, unsigned long event) >> } >> >> /* >> + * For all counters on the CCI-PMU, disable any 'enabled' counters, >> + * saving the changed counters in the mask, so that we can restore >> + * it later using pmu_restore_counters. The mask is private to the >> + * caller. We cannot rely on the used_mask maintained by the CCI_PMU >> + * as it only tells us if the counter is assigned to perf_event or not. >> + * The state of the perf_event cannot be locked by the PMU layer, hence >> + * we check the individual counter status (which can be locked by >> + * cci_pm->hw_events->pmu_lock). >> + * >> + * @mask should be initialised by the caller. > > We should probably state "initialised to zero", or "empty". Yep, will fix it. >> +/* >> + * Restore the status of the counters. Reversal of the pmu_disable_counters(). >> + * For each counter set in the mask, enable the counter back. >> + */ > > Shouldn't that say pmu_save_counters? Yea, missed it in rebase. > With that: > > Acked-by: Mark Rutland > Thanks Suzuki