From nobody Mon Feb 9 17:21:46 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 6177211738 for ; Fri, 23 Feb 2024 05:19:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708665545; cv=none; b=sYhFew7U3z1SaT7s3F9ENzCyVxK44zKTF+Bl1QK1bggI9CMWK+OKbnbA4PYeiAJF1cof4IEHuprg4dgOSHiRvfOQbbJiz4qhIcM4iv6ZbaoHNmt8DS9sUqUsl3Bl8mCu97FTi91i7GfGvVPEnN4DMhgDnedExJ/M0O/2JZwAlpY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708665545; c=relaxed/simple; bh=Tk9A4I0oMmelCpHSwdKZxqF1e4tJfbiF9SDU75PTANQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JW01FW6N+xBciHXKaALe3ZS/cxw0sotytTEiu9ZebPy4BLgU1b4RKZmUKAI9Q905rOd97LdDuEFsfM64VEU21j404FW2PCWgVcDOdokck8g4emgK350JwfnHaTPpuO8ki1ju39vTIptjQG/7gM9Dbi3igbjcV/PYsiFbxSzZ2Rg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XoUy9ZEh; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XoUy9ZEh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1708665544; x=1740201544; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Tk9A4I0oMmelCpHSwdKZxqF1e4tJfbiF9SDU75PTANQ=; b=XoUy9ZEhcb/1WdMDoh2xB+cxXgDkXzLTQq1CA/zYUy0eFejj2EiJYHAl QKXC99QAtS+bL+0whhLWtlpARk2t10FpgajrYXPb7XyWUfAt6fC3Q2Jeb AsVt6XmVd9YJB+EztX8xj0Ju93913+xIvCxNtMwTR5JEu8zlpAdux272v rbmzXU0pcREbNUis9Lh+NXMGvFOGXGhMgekUb3xLMQt76ErNpKiu12+L/ w7X7pVWN9/vPmGBdshMHurSFFwMhjNhgNcFlsdU3T2j0p9DrBRA0RcZMt TcwhYKQhpTxbh+MEF+CKAj+qOq8NXc+UsKKx/ndqo0NXm6whDzjnZccTh w==; X-IronPort-AV: E=McAfee;i="6600,9927,10992"; a="28395436" X-IronPort-AV: E=Sophos;i="6.06,179,1705392000"; d="scan'208";a="28395436" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Feb 2024 21:19:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,179,1705392000"; d="scan'208";a="5999892" Received: from allen-box.sh.intel.com ([10.239.159.127]) by fmviesa006.fm.intel.com with ESMTP; 22 Feb 2024 21:19:02 -0800 From: Lu Baolu To: Joerg Roedel , Will Deacon , Robin Murphy , Jason Gunthorpe , Kevin Tian , Eric Badger Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Lu Baolu , Jason Gunthorpe Subject: [PATCH 1/2] iommu: Add static iommu_ops->release_domain Date: Fri, 23 Feb 2024 13:13:01 +0800 Message-Id: <20240223051302.177596-2-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240223051302.177596-1-baolu.lu@linux.intel.com> References: <20240223051302.177596-1-baolu.lu@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The current device_release callback for individual iommu drivers does the following: 1) Silent IOMMU DMA translation: It detaches any existing domain from the device and puts it into a blocking state (some drivers might use the identity state). 2) Resource release: It releases resources allocated during the device_probe callback and restores the device to its pre-probe state. Step 1 is challenging for individual iommu drivers because each must check if a domain is already attached to the device. Additionally, if a deferred attach never occurred, the device_release should avoid modifying hardware configuration regardless of the reason for its call. To simplify this process, introduce a static release_domain within the iommu_ops structure. It can be either a blocking or identity domain depending on the iommu hardware. The iommu core will decide whether to attach this domain before the device_release callback, eliminating the need for repetitive code in various drivers. Consequently, the device_release callback can focus solely on the opposite operations of device_probe, including releasing all resources allocated during that callback. Co-developed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian --- include/linux/iommu.h | 1 + drivers/iommu/iommu.c | 12 ++++++++++++ 2 files changed, 13 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index de839fd01bb8..e3d9365b0fa9 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -585,6 +585,7 @@ struct iommu_ops { struct module *owner; struct iommu_domain *identity_domain; struct iommu_domain *blocked_domain; + struct iommu_domain *release_domain; struct iommu_domain *default_domain; }; =20 diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 210dc7b4c8cf..fb06c3f47320 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -459,6 +459,18 @@ static void iommu_deinit_device(struct device *dev) =20 iommu_device_unlink(dev->iommu->iommu_dev, dev); =20 + /* + * If the iommu driver provides release_domain then the core code + * ensures that domain is attached prior to calling release_device. + * Drivers can use this to enforce a translation on the idle iommu. + * Usually the global static blocked_domain is a good choice. + * + * Anyway, if a deferred attach never happened then the release + * should still avoid touching any hardware configuration either. + */ + if (!dev->iommu->attach_deferred && ops->release_domain) + ops->release_domain->ops->attach_dev(ops->release_domain, dev); + /* * release_device() must stop using any attached domain on the device. * If there are still other devices in the group they are not effected --=20 2.34.1