From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C5F8C77B7C for ; Tue, 9 May 2023 21:20:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235610AbjEIVTo (ORCPT ); Tue, 9 May 2023 17:19:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230023AbjEIVTm (ORCPT ); Tue, 9 May 2023 17:19:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DA62198A; Tue, 9 May 2023 14:19:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A569661794; Tue, 9 May 2023 21:19:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC9BEC433D2; Tue, 9 May 2023 21:19:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1683667180; bh=RkcAtB480GYQA9hn42rA8rzoGc08MhttzYGEylxcyW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OIa2KRNMDsBD+i1HYnktaEso+Y9/S/fIIOkMakQcjsRcnaktD7xYyGHYzTz0twbe+ 6TBYwEf+S9onMNOo+s+/3St294G0Q780jgMwMdiC+ExK8/pd0gGKo6gUifsZcMdZvw TEftFCK2z+xUTz6ElM9RkviRINHM9Q6Z/+WZohP+ouX0L+/W7iBDHqrqXuTY7JJGwt DK2iLMfbau+QHpqEwYeI6xWZvW+cHhTG/+Jcw+JwXgOb8k6P7TpQ6wIljgAjudXPP5 oDAr3SozRxxnBBFeCh5XDRxf9JeHDgNibPMzLfZgITPGoga98Ijp8nj+bpZol7STII 52rILDIOC1qDQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Manivannan Sadhasivam , Johan Hovold , Will Deacon , Sasha Levin , joro@8bytes.org, dmitry.baryshkov@linaro.org, quic_saipraka@quicinc.com, konrad.dybcio@linaro.org, quic_bjorande@quicinc.com, a39.skl@gmail.com, quic_eberman@quicinc.com, mani@kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev Subject: [PATCH AUTOSEL 6.3 03/18] iommu/arm-smmu-qcom: Limit the SMR groups to 128 Date: Tue, 9 May 2023 17:19:11 -0400 Message-Id: <20230509211928.21010-3-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230509211928.21010-1-sashal@kernel.org> References: <20230509211928.21010-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Manivannan Sadhasivam [ Upstream commit 12261134732689b7e30c59db9978f81230965181 ] Some platforms support more than 128 stream matching groups than what is defined by the ARM SMMU architecture specification. But due to some unknown reasons, those additional groups don't exhibit the same behavior as the architecture supported ones. For instance, the additional groups will not detect the quirky behavior of some firmware versions intercepting writes to S2CR register, thus skipping the quirk implemented in the driver and causing boot crash. So let's limit the groups to 128 for now until the issue with those groups are fixed and issue a notice to users in that case. Reviewed-by: Johan Hovold Tested-by: Johan Hovold Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20230327080029.11584-1-manivannan.sadhasivam@linaro.org [will: Reworded the comment slightly] Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c index d1b296b95c860..ae09c627bc844 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -268,12 +268,26 @@ static int qcom_smmu_init_context(struct arm_smmu_domain *smmu_domain, static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu) { - unsigned int last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1); struct qcom_smmu *qsmmu = to_qcom_smmu(smmu); + unsigned int last_s2cr; u32 reg; u32 smr; int i; + /* + * Some platforms support more than the Arm SMMU architected maximum of + * 128 stream matching groups. For unknown reasons, the additional + * groups don't exhibit the same behavior as the architected registers, + * so limit the groups to 128 until the behavior is fixed for the other + * groups. + */ + if (smmu->num_mapping_groups > 128) { + dev_notice(smmu->dev, "\tLimiting the stream matching groups to 128\n"); + smmu->num_mapping_groups = 128; + } + + last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1); + /* * With some firmware versions writes to S2CR of type FAULT are * ignored, and writing BYPASS will end up written as FAULT in the -- 2.39.2