From patchwork Wed Jun 12 07:15:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Gautam X-Patchwork-Id: 10988783 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 637A71515 for ; Wed, 12 Jun 2019 07:16:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C3D028899 for ; Wed, 12 Jun 2019 07:16:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3A3AD289BE; Wed, 12 Jun 2019 07:16:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8FE8528899 for ; Wed, 12 Jun 2019 07:16:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407713AbfFLHQc (ORCPT ); Wed, 12 Jun 2019 03:16:32 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:45932 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408354AbfFLHQX (ORCPT ); Wed, 12 Jun 2019 03:16:23 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 46A9660E3F; Wed, 12 Jun 2019 07:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560323781; bh=APUZKQMxuCP659BLXKIfQYp8vw7FUPYUW6I8vlsYHKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WWVUXPnaXnHiulNfWvtH5nOZVLrIh9sMMLqGDIqFgyWrsltehuCCzqfH7I7WKzbeZ 3GOuyxcWz4yEDdBGNjMu8nFYiDkussE/HKii63G2QzR/Sir+bzYKq8haCh5mnJX7AV YqOEQAfax+zUTXDBmd2eESdTrikVW42m7J3B4aDw= Received: from blr-ubuntu-41.ap.qualcomm.com (blr-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: vivek.gautam@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 0460A60C5F; Wed, 12 Jun 2019 07:16:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560323780; bh=APUZKQMxuCP659BLXKIfQYp8vw7FUPYUW6I8vlsYHKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pLoy65s9zcPXgJwk2N1Ihcrgoe/s1SQosjj4Wx3VF5Fvg8PL+T4ucJjI+okIXqpPi jX8uwElLvruClZwI7ypKsneIgozLty/I81GHv5SodkkFZGg/W3LWqgI3JoU5nzLUvH h0Xi3d/4dsICjWPnwUmtWO4Q/N4rEryR3RctCR7U= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 0460A60C5F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=vivek.gautam@codeaurora.org From: Vivek Gautam To: agross@kernel.org, robh+dt@kernel.org, will.deacon@arm.com, robin.murphy@arm.com, joro@8bytes.org, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, david.brown@linaro.org, Vivek Gautam Subject: [PATCH v3 3/4] iommu/arm-smmu: Add support to handle Qcom's wait-for-safe logic Date: Wed, 12 Jun 2019 12:45:53 +0530 Message-Id: <20190612071554.13573-4-vivek.gautam@codeaurora.org> X-Mailer: git-send-email 2.16.1.72.g5be1f00a9a70 In-Reply-To: <20190612071554.13573-1-vivek.gautam@codeaurora.org> References: <20190612071554.13573-1-vivek.gautam@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Qcom's implementation of arm,mmu-500 adds a WAIT-FOR-SAFE logic to address under-performance issues in real-time clients, such as Display, and Camera. On receiving an invalidation requests, the SMMU forwards SAFE request to these clients and waits for SAFE ack signal from real-time clients. The SAFE signal from such clients is used to qualify the start of invalidation. This logic is controlled by chicken bits, one for each - MDP (display), IFE0, and IFE1 (camera), that can be accessed only from secure software on sdm845. This configuration, however, degrades the performance of non-real time clients, such as USB, and UFS etc. This happens because, with wait-for-safe logic enabled the hardware tries to throttle non-real time clients while waiting for SAFE ack signals from real-time clients. On MTP sdm845 devices, with wait-for-safe logic enabled at the boot time by the bootloaders we see degraded performance of USB and UFS when kernel enables the smmu stage-1 translations for these clients. Turn off this wait-for-safe logic from the kernel gets us back the perf of USB and UFS devices until we re-visit this when we start seeing perf issues on display/camera on upstream supported SDM845 platforms. Now, different bootloaders with their access control policies allow this register access differently through secure monitor calls - 1) With one we can issue io-read/write secure monitor call (qcom-scm) to update the register, while, 2) With other, such as one on MTP sdm845 we should use the specific qcom-scm command to send request to do the complete register configuration. Adding a separate device tree flag for arm-smmu to identify which firmware configuration of the two mentioned above we use. Not adding code change to allow type-(1) bootloaders to toggle the safe using io-read/write qcom-scm call. This change is inspired by the downstream change from Patrick Daly to address performance issues with display and camera by handling this wait-for-safe within separte io-pagetable ops to do TLB maintenance. So a big thanks to him for the change. Without this change the UFS reads are pretty slow: $ time dd if=/dev/sda of=/dev/zero bs=1048576 count=10 conv=sync 10+0 records in 10+0 records out 10485760 bytes (10.0MB) copied, 22.394903 seconds, 457.2KB/s real 0m 22.39s user 0m 0.00s sys 0m 0.01s With this change they are back to rock! $ time dd if=/dev/sda of=/dev/zero bs=1048576 count=300 conv=sync 300+0 records in 300+0 records out 314572800 bytes (300.0MB) copied, 1.030541 seconds, 291.1MB/s real 0m 1.03s user 0m 0.00s sys 0m 0.54s Signed-off-by: Vivek Gautam Reviewed-by: Bjorn Andersson --- drivers/iommu/arm-smmu.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 0ad086da399c..3c3ad43eda97 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -177,6 +178,7 @@ struct arm_smmu_device { u32 features; #define ARM_SMMU_OPT_SECURE_CFG_ACCESS (1 << 0) +#define ARM_SMMU_OPT_QCOM_FW_IMPL_SAFE_ERRATA (1 << 1) u32 options; enum arm_smmu_arch_version version; enum arm_smmu_implementation model; @@ -262,6 +264,7 @@ static bool using_legacy_binding, using_generic_binding; static struct arm_smmu_option_prop arm_smmu_options[] = { { ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" }, + { ARM_SMMU_OPT_QCOM_FW_IMPL_SAFE_ERRATA, "qcom,smmu-500-fw-impl-safe-errata" }, { 0, NULL}, }; @@ -2292,6 +2295,19 @@ static int arm_smmu_device_probe(struct platform_device *pdev) arm_smmu_device_reset(smmu); arm_smmu_test_smr_masks(smmu); + /* + * To address performance degradation in non-real time clients, + * such as USB and UFS, turn off wait-for-safe on sdm845 platforms, + * such as MTP, whose firmwares implement corresponding secure monitor + * call handlers. + */ + if (of_device_is_compatible(smmu->dev->of_node, "qcom,sdm845-smmu-500") && + smmu->options & ARM_SMMU_OPT_QCOM_FW_IMPL_SAFE_ERRATA) { + err = qcom_scm_qsmmu500_wait_safe_toggle(0); + if (err) + dev_warn(dev, "Failed to turn off SAFE logic\n"); + } + /* * We want to avoid touching dev->power.lock in fastpaths unless * it's really going to do something useful - pm_runtime_enabled()