From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout08.his.huawei.com (canpmsgout08.his.huawei.com [113.46.200.223]) (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 AE35F3264FB for ; Wed, 20 May 2026 06:37:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.223 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259051; cv=none; b=E3150S4ayJZouJf5DvHXWCzh6dSRRI8K50jDmYYcytxjKFO0KdfmC/likNXT53nAQFYzC/FQYkZsFbb4jLYK8XDYA2naLTovbI1RXDoTWNfQvOTEvvirVj7qeH/jZp7+En3Kq7EiKfqY+ljYBsV167BOL9Ea0hdzg/sk73cLgXQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259051; c=relaxed/simple; bh=DzIvXEPRpUnLdxbztLyI8mfkLLg2gKXJlYBeY7YN3+Y=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=aj8ZWEujlZyLV+VAXMS1/Rnfsq0iN6//Ax6amNyYk0vCH52pXsqYAMGhFS7tW2oFIib1rZWcupdraNxkauCglNE9dXUiO3s+jgaeuA4+NfgE5V1lXmN/41toZ6+GG78auMYZEjYaxwvrHC1ImexDTIbp5WicQ0h1d1wbAN+u4ls= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=QT1059j1; arc=none smtp.client-ip=113.46.200.223 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="QT1059j1" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=Zm93bQ5t5C8w3D4+hr9H/ydh/Ma2k3/VoNQRmowXLsA=; b=QT1059j1BWnvmMdNIVY6DikiGb3SFgT693wP6J7Rc0fFQUKsEwpd4IkCOcew3jEjEvIYFPNPV nCBUs2EnyUYBspugMmQr5/p8U4A0g0xgU9dDy3JKkgBhDqSnxkMsx7A5EjTHfMvBJeUGiz6c/cm gG9b1vPjZ++9HQH2mi3qh+k= Received: from mail.maildlp.com (unknown [172.19.163.127]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4gL1q03gV5zmVD0; Wed, 20 May 2026 14:29:32 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id 08E0F40572; Wed, 20 May 2026 14:37:15 +0800 (CST) Received: from localhost.huawei.com (10.90.31.46) by kwepemj200003.china.huawei.com (7.202.194.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 20 May 2026 14:37:14 +0800 From: Qinxin Xia To: , , , CC: , , , , , , , , , Subject: [PATCH 0/5] Add debugfs support for ARM SMMUv3 Date: Wed, 20 May 2026 14:37:06 +0800 Message-ID: <20260328101706.3448655-1-xiaqinxin@huawei.com> X-Mailer: git-send-email 2.33.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemj200003.china.huawei.com (7.202.194.15) Add a comprehensive debugfs framework to the ARM SMMUv3 driver, providing visibility into internal hardware state for debugging and performance analysis. The debugfs entries are organized under /sys/kernel/debug/iommu/arm_smmu_v3/, with per-SMMU instance directories and per-device stream table entries. Each SMMU instance provides: - capabilities – static SMMU features and queue sizes. - registers – SMMU key registers. - stream_table/ – a directory per device with subdirectories per Stream ID. Each Stream ID subdirectory contains: - ste – the Stream Table Entry in decoded and raw format. - cd – all valid Context Descriptors (Stage 1 translation tables) associated with the device. - a symlink named with the device's BDF/name pointing to its sysfs directory for easy navigation. /sys/kernel/debug/iommu/arm_smmu_v3/smmu0/stream_table/ ├── / │ ├── ste │ ├── cd │ └── Changes since RFCv2: Address review comments from Nicolin Chen, kernel test robot, and Sashiko automated review: Build & kerneldoc fixes (patches 1-3): - Add missing @unused parameter description to kerneldoc comments to fix clang W=1 warnings reported by kernel test robot. - Fix commit message: "driver.This" -> "driver. This" (patch 1). Correctness fixes: - Fix integer overflow: 1 << sid_bits -> 1ULL << sid_bits with %llu format, preventing undefined behavior when SIDSIZE = 32 (patch 1). - Fix EVTQ register access: use smmu->page1 instead of smmu->base for EVTQ_PROD/EVTQ_CONS, which reside in register page 1 (patch 2). - Fix STE config bit test: use proper cfg comparison instead of bitwise AND on non-mask enumeration values, and extract S1ContextPtr from data[0] instead of data[1] (patch 3). Resource leak fixes (patches 1-5): - Fix device reference leak: call put_device() when single_open() fails in all open() callbacks (capabilities, registers, ste, cd). - Fix dentry reference leak: add missing dput() after debugfs_lookup() in stream table remove path (patch 3). - Move kobject_get_path() outside the per-stream loop to avoid repeated allocation (patch 4). Locking & concurrency fixes: - arm_smmu_debugfs_remove(): use scoped_guard() and move debugfs_remove_recursive() outside the lock to avoid blocking other SMMU instances on active VFS operations (patch 1). - smmu_debugfs_ste_show(): change scoped_guard to guard(mutex) since the entire function body is within the lock scope (patch 3). - smmu_debugfs_cd_show(): change manual mutex_lock/unlock to guard(mutex)(&arm_smmu_asid_lock) (patch 5). Error handling fixes: - Replace if (!debugfs_create_dir(...)) with IS_ERR() checks throughout, since debugfs_create_dir() returns ERR_PTR on failure, not NULL (patches 1, 3). - Add NULL check for smmu->debugfs before dereference in stream table create path (patch 3). - Add NULL check for kzalloc_obj() result (patch 3). Code style & cleanup: - Directory tree comment: use ├── for last entry to avoid churn on subsequent patches (patches 1-5). - Fix tab/space alignment in directory tree comments (patches 1, 2). - Reorder function parameters: @smmu first, @dev second (patch 3). - Fix return statement indentation (patch 3). - Move function declarations from #ifndef-static pattern to header file (patch 3). - Move char name[32] and snprintf() to function top for reuse by iommu_device_sysfs_add() regardless of CONFIG_ARM_SMMU_V3_DEBUGFS (patch 1). - Adopt non-tab-aligned style for new struct members (patches 1, 3). - Remove useless comments: "DebugFS Info" and "Reserved for future extensions" (patches 1, 3). - Remove spurious blank line (patch 3). - Link: https://lore.kernel.org/all/20260328101706.3448655-1-xiaqinxin@huawei.com/ Qinxin Xia (5): iommu/arm-smmu-v3: Add basic debugfs framework iommu/arm-smmu-v3: Add register display to debugfs iommu/arm-smmu-v3: Add Stream Table Entry display to debugfs iommu/arm-smmu-v3: Add device symlink in stream table debugfs iommu/arm-smmu-v3: Add Context Descriptor display to debugfs drivers/iommu/Kconfig | 11 + drivers/iommu/arm/arm-smmu-v3/Makefile | 1 + .../iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c | 609 +++++++++++++++++++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 27 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 30 + 5 files changed, 675 insertions(+), 3 deletions(-) create mode 100644 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c -- 2.51.0