From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6E1871C231F for ; Fri, 16 Aug 2024 18:33:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723833196; cv=none; b=SRdoDcnXWrF2FX7lJBS+WfER2t6EqQ6KkdiQ9/0D6yaVo3Y/fP1a8aK+ZZfP1v3vasn0qBWK1TZfv3IDYPbAWbjQzaK6mrSeK381IM1DY1EOLqPL8x+214oU3gqqhwLtiu+CQtFv/Lej24fWCXU7fY1DmraxQInnTQHsUo46XpQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723833196; c=relaxed/simple; bh=HgrFxERRhvFkyAKVdhaZs5z2jyxxDEf3sl0uhCt50Ok=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pAlAWlOxsRDrG/zcW/sSA1f0E86CZu+zK4+uZlzZ6shf1SbrFXBdMuOkbs4zHmKE+R9+Jp6hRKU3urV0IWernUVRf/vLsR5Qtse3tI6x0qnNlsjLXDfaAznJuwhyBAZNyxBudzs4Yn7IhMZulLz0acZzjMZj2wuUyBECkNLfUn0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3022913D5; Fri, 16 Aug 2024 11:33:39 -0700 (PDT) Received: from [10.1.196.40] (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8DF303F6A8; Fri, 16 Aug 2024 11:33:12 -0700 (PDT) Message-ID: Date: Fri, 16 Aug 2024 19:33:11 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/8] perf/arm-cmn: Fix CCLA register offset To: Mark Rutland Cc: will@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, ilkka@os.amperecomputing.com References: From: Robin Murphy Content-Language: en-GB In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 16/08/2024 11:00 am, Mark Rutland wrote: > On Fri, Aug 09, 2024 at 08:15:41PM +0100, Robin Murphy wrote: >> Apparently pmu_event_sel is offset by 8 for all CCLA nodes, not just >> the CCLA_RNI combination type. > > Was there some reason we used to think that was specific to CCLA_RNI > nodes, or was that just an oversight? I imagine it was just oversight/confusion helped by the original r0p0 TRM listing both a por_ccla_pmu_event_sel and a por_ccla_rni_pmu_event_sel as CCLA registers, which I could well believe I misread at a glance while scrolling up and down. > Looking at the CMN-700 TRM and scanning for pmu_event_sel, we have: > > 16'h2000 por_ccg_ha_pmu_event_sel > 16'h2000 por_ccg_ra_pmu_event_sel > 16'h2008 por_ccla_pmu_event_sel > 16'h2000 por_dn_pmu_event_sel > 16'h2000 cmn_hns_pmu_event_sel > 16'h2000 por_hni_pmu_event_sel > 16'h2008 por_hnp_pmu_event_sel > 16'h2000 por_mxp_pmu_event_sel > 16'h2000 por_rnd_pmu_event_sel > 16'h2000 por_rni_pmu_event_sel > 16'h2000 por_sbsx_pmu_event_sel > >> Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support") >> Signed-off-by: Robin Murphy >> --- >> drivers/perf/arm-cmn.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c >> index fd2122a37f22..0e2e12e2f4fb 100644 >> --- a/drivers/perf/arm-cmn.c >> +++ b/drivers/perf/arm-cmn.c >> @@ -2393,10 +2393,13 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) >> case CMN_TYPE_CXHA: >> case CMN_TYPE_CCRA: >> case CMN_TYPE_CCHA: >> - case CMN_TYPE_CCLA: >> case CMN_TYPE_HNS: >> dn++; >> break; >> + case CMN_TYPE_CCLA: >> + dn->pmu_base += CMN_HNP_PMU_EVENT_SEL; >> + dn++; >> + break; > > When reading this for the first time, it looks like a copy-paste error > since CMN_HNP_PMU_EVENT_SEL doesn't have any obvious relationship with > CCLA nodes. > > I reckon it'd be worth adding CMN_CCLA_PMU_EVENT_SEL, and replacing the > existing comment above the definition of CMN_HNP_PMU_EVENT_SEL, e.g. > > /* > * Some nodes place common registers at different offsets from most > * other nodes. > */ > #define CMN_HNP_PMU_EVENT_SEL 0x008 > #define CMN_CCLA_PMU_EVENT_SEL 0x008 > > That way the switch looks less suspicious, and the comment is a bit more > helpful to anyone trying to figure out what's going on here. Sure, that's a reasonable argument. > With that: > > Acked-by: Mark Rutland Thanks, Robin. > > Mark. > >> /* Nothing to see here */ >> case CMN_TYPE_MPAM_S: >> case CMN_TYPE_MPAM_NS: >> -- >> 2.39.2.101.g768bb238c484.dirty >>