From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BA608F70 for ; Sun, 16 Jul 2023 19:55:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E486BC433C7; Sun, 16 Jul 2023 19:55:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689537345; bh=QIIKj1stxsHvFvyancywOBzssjpWkmDJYitYrJuaPEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j60yZBECD7PnsDsdG1JS3SpxCXiYH2GJUshL/rN8J57nbf8e3bb0OZYtB0k+UrOU2 TjoENhPovm5nwDFBLV0IO+NefiAcJugfz/t0mgsSwsgLx8RZM4ice55LsY4tKLUlDD t9agEcBiUYqkg183QLu2wc6jUtB4rucPXDCLOwK8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Geoff Blake , Robin Murphy , Will Deacon , Sasha Levin Subject: [PATCH 6.4 063/800] perf/arm-cmn: Fix DTC reset Date: Sun, 16 Jul 2023 21:38:36 +0200 Message-ID: <20230716194950.553736629@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194949.099592437@linuxfoundation.org> References: <20230716194949.099592437@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Robin Murphy [ Upstream commit 71746c995cac92fcf6a65661b51211cf2009d7f0 ] It turns out that my naive DTC reset logic fails to work as intended, since, after checking with the hardware designers, the PMU actually needs to be fully enabled in order to correctly clear any pending overflows. Therefore, invert the sequence to start with turning on both enables so that we can reliably get the DTCs into a known state, then moving to our normal counters-stopped state from there. Since all the DTM counters have already been unpaired during the initial discovery pass, we just need to additionally reset the cycle counters to ensure that no other unexpected overflows occur during this period. Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver") Reported-by: Geoff Blake Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/0ea4559261ea394f827c9aee5168c77a60aaee03.1684946389.git.robin.murphy@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/perf/arm-cmn.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index 47d359f729579..89a685a09d848 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -1899,9 +1899,10 @@ static int arm_cmn_init_dtc(struct arm_cmn *cmn, struct arm_cmn_node *dn, int id if (dtc->irq < 0) return dtc->irq; - writel_relaxed(0, dtc->base + CMN_DT_PMCR); + writel_relaxed(CMN_DT_DTC_CTL_DT_EN, dtc->base + CMN_DT_DTC_CTL); + writel_relaxed(CMN_DT_PMCR_PMU_EN | CMN_DT_PMCR_OVFL_INTR_EN, dtc->base + CMN_DT_PMCR); + writeq_relaxed(0, dtc->base + CMN_DT_PMCCNTR); writel_relaxed(0x1ff, dtc->base + CMN_DT_PMOVSR_CLR); - writel_relaxed(CMN_DT_PMCR_OVFL_INTR_EN, dtc->base + CMN_DT_PMCR); return 0; } @@ -1961,7 +1962,7 @@ static int arm_cmn_init_dtcs(struct arm_cmn *cmn) dn->type = CMN_TYPE_CCLA; } - writel_relaxed(CMN_DT_DTC_CTL_DT_EN, cmn->dtc[0].base + CMN_DT_DTC_CTL); + arm_cmn_set_state(cmn, CMN_STATE_DISABLED); return 0; } -- 2.39.2