From patchwork Thu Dec 12 15:13:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bibek Kumar Patro X-Patchwork-Id: 13905336 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (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 2E9AE21770A; Thu, 12 Dec 2024 15:14:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734016489; cv=none; b=RnYwg7YpkCbwRDEo8LeziD1kfLjPohe1RfojLJ8GKzV89I6Qk03GD8uKYE5x30NOowgMNUpm4gSCe+oI8a12L5aAPBzZoRlMMslTgtTNEYVJdy+cIVsScgT70NVwGWDaSvti1038u4wPS+2Fg5MtGB+VuA9ItMX31nS6Q84O3dE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734016489; c=relaxed/simple; bh=PlchT+XiQ1/CHEhIpjvktYyhkY53vzR2SSElaI/2w4I=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SifxH0sck1NX9d84brI/GM1R8T3psbuhv6roLru219fask0ZeLdveEjtU5I6hpV4DK+73dEEFudEMuKsiJW9MqK9Yg2XPdWbh9/Z4xQS0DecK8pjWMaP7iw7lGoep5+rsrNyLw8dYYSVssx0GSE1HATCxx8mWlgLxURyi2R8mso= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=WStYJ28b; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="WStYJ28b" Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4BCD1R7x000455; Thu, 12 Dec 2024 15:14:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= X/bj4EVljuLLe36faJM5+8RziYdbMI4NZu4xd4aurqI=; b=WStYJ28b3DOd2rT0 gt9KMilaBviEFWjH+Ogj/eHUYOdZKGMOjniDeJ8dhDwCbE6KJybdGqVTukc9MAfY TYQFtl1Z+D/PrbjKxGEhBxoB1COqloMwR7X4W1XZVEs1OOOlX1BunbnqlbUgnEqP mLWVkflHaNeKFwYT0uI7qwdXOao0OWvdx4Fg9fkb4uvVuEMweRVl0ZlledKw11bD 9rQOA4a410VtMil2H6lVfgyB0I9Ki+mxlRWIlt5GtG+rD0zybw+q7EPAjoUn+t0T 9Op0ZfEdu49B3eI4qm9cHXRqSd8nRc8dBsQLxT7h+5jtox+DLS5ahgl6p5N3Gy/z PFj3zQ== Received: from nasanppmta04.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 43fqes1v8e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 12 Dec 2024 15:14:34 +0000 (GMT) Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA04.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 4BCFEXeO028235 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 12 Dec 2024 15:14:33 GMT Received: from hu-bibekkum-hyd.qualcomm.com (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Thu, 12 Dec 2024 07:14:28 -0800 From: Bibek Kumar Patro To: , , , , , , , , , CC: , , , , Subject: [PATCH v18 1/5] iommu/arm-smmu: re-enable context caching in smmu reset operation Date: Thu, 12 Dec 2024 20:43:58 +0530 Message-ID: <20241212151402.159102-2-quic_bibekkum@quicinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241212151402.159102-1-quic_bibekkum@quicinc.com> References: <20241212151402.159102-1-quic_bibekkum@quicinc.com> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 7h582FV6A5RxDmHdeZcHXwjlJ56OlL5e X-Proofpoint-ORIG-GUID: 7h582FV6A5RxDmHdeZcHXwjlJ56OlL5e X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 adultscore=0 lowpriorityscore=0 impostorscore=0 clxscore=1015 malwarescore=0 mlxlogscore=999 priorityscore=1501 bulkscore=0 phishscore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2411120000 definitions=main-2412120110 Default MMU-500 reset operation disables context caching in prefetch buffer. It is however expected for context banks using the ACTLR register to retain their prefetch value during reset and runtime suspend. Add config 'ARM_SMMU_MMU_500_CPRE_ERRATA' to gate this errata workaround in default MMU-500 reset operation which defaults to 'Y' and provide option to disable workaround for context caching in prefetch buffer as and when needed. Suggested-by: Will Deacon Signed-off-by: Bibek Kumar Patro --- Documentation/arch/arm64/silicon-errata.rst | 3 ++- drivers/iommu/Kconfig | 12 ++++++++++++ drivers/iommu/arm/arm-smmu/arm-smmu-impl.c | 5 +++-- 3 files changed, 17 insertions(+), 3 deletions(-) -- 2.34.1 diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index 65bfab1b1861..92207d55fd1c 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -198,7 +198,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ -| ARM | MMU-500 | #841119,826419 | N/A | +| ARM | MMU-500 | #841119,826419 | ARM_SMMU_MMU_500_CPRE_ERRATA| +| | | #562869,1047329 | | +----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-600 | #1076982,1209401| N/A | +----------------+-----------------+-----------------+-----------------------------+ diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index ade4e8cf2a3e..90ba5818af81 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -367,6 +367,18 @@ config ARM_SMMU_DISABLE_BYPASS_BY_DEFAULT 'arm-smmu.disable_bypass' will continue to override this config. +config ARM_SMMU_MMU_500_CPRE_ERRATA + bool "Enable errata workaround for CPRE in SMMU reset path" + depends on ARM_SMMU + default y + help + Say Y here (by default) to apply workaround to disable + MMU-500's next-page prefetcher for sake of 4 known errata. + + Say N here only when it is sure that any errata related to + prefetch enablement are not applicable on the platform. + Refer silicon-errata.rst for info on errata IDs. + config ARM_SMMU_QCOM def_tristate y depends on ARM_SMMU && ARCH_QCOM diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c index 99030e6b16e7..db9b9a8e139c 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-impl.c @@ -110,7 +110,6 @@ static struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smm int arm_mmu500_reset(struct arm_smmu_device *smmu) { u32 reg, major; - int i; /* * On MMU-500 r2p0 onwards we need to clear ACR.CACHE_LOCK before * writes to the context bank ACTLRs will stick. And we just hope that @@ -128,11 +127,12 @@ int arm_mmu500_reset(struct arm_smmu_device *smmu) reg |= ARM_MMU500_ACR_SMTNMB_TLBEN | ARM_MMU500_ACR_S2CRB_TLBEN; arm_smmu_gr0_write(smmu, ARM_SMMU_GR0_sACR, reg); +#ifdef CONFIG_ARM_SMMU_MMU_500_CPRE_ERRATA /* * Disable MMU-500's not-particularly-beneficial next-page * prefetcher for the sake of at least 5 known errata. */ - for (i = 0; i < smmu->num_context_banks; ++i) { + for (int i = 0; i < smmu->num_context_banks; ++i) { reg = arm_smmu_cb_read(smmu, i, ARM_SMMU_CB_ACTLR); reg &= ~ARM_MMU500_ACTLR_CPRE; arm_smmu_cb_write(smmu, i, ARM_SMMU_CB_ACTLR, reg); @@ -140,6 +140,7 @@ int arm_mmu500_reset(struct arm_smmu_device *smmu) if (reg & ARM_MMU500_ACTLR_CPRE) dev_warn_once(smmu->dev, "Failed to disable prefetcher for errata workarounds, check SACR.CACHE_LOCK\n"); } +#endif return 0; }