From nobody Tue Sep 9 01:24:35 2025 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 25687EB64DD for ; Thu, 20 Jul 2023 23:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229936AbjGTXYE (ORCPT ); Thu, 20 Jul 2023 19:24:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229824AbjGTXXz (ORCPT ); Thu, 20 Jul 2023 19:23:55 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 96D74270D; Thu, 20 Jul 2023 16:23:53 -0700 (PDT) Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 1B603236EBEE; Thu, 20 Jul 2023 16:23:53 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1B603236EBEE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1689895433; bh=IGGYFXNUvMQx09Tnw6sJKKjcZi3QrY5MCquaxh4wmqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MRPhxgbgNRdD4NZWGJGJDGHeHVSh5117liIEIAHzo4Vhkk0hnlnwgHEt0Dp2IT5MM 8ClFRZOaFW7Hozi8IBPrV32GTdVgXrmamPWbrjevOv6rfuzn59XMhqMT2qWMG2uiYa BUcUn7CP6CesQ7hTRX+uQ7J11Pnjeanb5vGoyuog= From: Easwar Hariharan To: stable@vger.kernel.org Cc: easwar.hariharan@microsoft.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, robin.murphy@arm.com, joro@8bytes.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev Subject: [PATCH 5.15 4/4] iommu/arm-smmu-v3: Document MMU-700 erratum 2812531 Date: Thu, 20 Jul 2023 16:23:34 -0700 Message-Id: <1689895414-17425-5-git-send-email-eahariha@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1689895414-17425-1-git-send-email-eahariha@linux.microsoft.com> References: <1689895414-17425-1-git-send-email-eahariha@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Robin Murphy commit 309a15cb16bb075da1c99d46fb457db6a1a2669e upstream To work around MMU-700 erratum 2812531 we need to ensure that certain sequences of commands cannot be issued without an intervening sync. In practice this falls out of our current command-batching machinery anyway - each batch only contains a single type of invalidation command, and ends with a sync. The only exception is when a batch is sufficiently large to need issuing across multiple command queue slots, wherein the earlier slots will not contain a sync and thus may in theory interleave with another batch being issued in parallel to create an affected sequence across the slot boundary. Since MMU-700 supports range invalidate commands and thus we will prefer to use them (which also happens to avoid conditions for other errata), I'm not entirely sure it's even possible for a single high-level invalidate call to generate a batch of more than 63 commands, but for the sake of robustness and documentation, wire up an option to enforce that a sync is always inserted for every slot issued. The other aspect is that the relative order of DVM commands cannot be controlled, so DVM cannot be used. Again that is already the status quo, but since we have at least defined ARM_SMMU_FEAT_BTM, we can explicitly disable it for documentation purposes even if it's not wired up anywhere yet. Signed-off-by: Robin Murphy Reviewed-by: Nicolin Chen Link: https://lore.kernel.org/r/330221cdfd0003cd51b6c04e7ff3566741ad8374.16= 83731256.git.robin.murphy@arm.com Signed-off-by: Will Deacon Signed-off-by: Easwar Hariharan --- Documentation/arm64/silicon-errata.rst | 4 ++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 41 +++++++++++++++++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 + 3 files changed, 46 insertions(+) diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/s= ilicon-errata.rst index f64354f8a79f..322df8abbc0e 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -122,6 +122,10 @@ stable kernels. +----------------+-----------------+-----------------+--------------------= ---------+ | ARM | MMU-500 | #841119,826419 | N/A = | +----------------+-----------------+-----------------+--------------------= ---------+ +| ARM | MMU-600 | #1076982 | N/A = | ++----------------+-----------------+-----------------+--------------------= ---------+ +| ARM | MMU-700 | #2812531 | N/A = | ++----------------+-----------------+-----------------+--------------------= ---------+ +----------------+-----------------+-----------------+--------------------= ---------+ | Broadcom | Brahma-B53 | N/A | ARM64_ERRATUM_84571= 9 | +----------------+-----------------+-----------------+--------------------= ---------+ diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/ar= m/arm-smmu-v3/arm-smmu-v3.c index bcdb2cbdda97..ba2e5149604c 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -897,6 +897,14 @@ static void arm_smmu_cmdq_batch_add(struct arm_smmu_de= vice *smmu, struct arm_smmu_cmdq_batch *cmds, struct arm_smmu_cmdq_ent *cmd) { + int index; + + if (cmds->num =3D=3D CMDQ_BATCH_ENTRIES - 1 && + (smmu->options & ARM_SMMU_OPT_CMDQ_FORCE_SYNC)) { + arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, true); + cmds->num =3D 0; + } + if (cmds->num =3D=3D CMDQ_BATCH_ENTRIES) { arm_smmu_cmdq_issue_cmdlist(smmu, cmds->cmds, cmds->num, false); cmds->num =3D 0; @@ -3459,6 +3467,39 @@ static int arm_smmu_device_reset(struct arm_smmu_dev= ice *smmu, bool bypass) return 0; } =20 +#define IIDR_IMPLEMENTER_ARM 0x43b +#define IIDR_PRODUCTID_ARM_MMU_600 0x483 +#define IIDR_PRODUCTID_ARM_MMU_700 0x487 + +static void arm_smmu_device_iidr_probe(struct arm_smmu_device *smmu) +{ + u32 reg; + unsigned int implementer, productid, variant, revision; + + reg =3D readl_relaxed(smmu->base + ARM_SMMU_IIDR); + implementer =3D FIELD_GET(IIDR_IMPLEMENTER, reg); + productid =3D FIELD_GET(IIDR_PRODUCTID, reg); + variant =3D FIELD_GET(IIDR_VARIANT, reg); + revision =3D FIELD_GET(IIDR_REVISION, reg); + + switch (implementer) { + case IIDR_IMPLEMENTER_ARM: + switch (productid) { + case IIDR_PRODUCTID_ARM_MMU_600: + /* Arm erratum 1076982 */ + if (variant =3D=3D 0 && revision <=3D 2) + smmu->features &=3D ~ARM_SMMU_FEAT_SEV; + break; + case IIDR_PRODUCTID_ARM_MMU_700: + /* Arm erratum 2812531 */ + smmu->features &=3D ~ARM_SMMU_FEAT_BTM; + smmu->options |=3D ARM_SMMU_OPT_CMDQ_FORCE_SYNC; + break; + } + break; + } +} + static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu) { u32 reg; diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/ar= m/arm-smmu-v3/arm-smmu-v3.h index 4cb136f07914..eeb780c5c1e0 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -645,6 +645,7 @@ struct arm_smmu_device { #define ARM_SMMU_OPT_SKIP_PREFETCH (1 << 0) #define ARM_SMMU_OPT_PAGE0_REGS_ONLY (1 << 1) #define ARM_SMMU_OPT_MSIPOLL (1 << 2) +#define ARM_SMMU_OPT_CMDQ_FORCE_SYNC (1 << 3) u32 options; =20 struct arm_smmu_cmdq cmdq; --=20 2.25.1