From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) (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 D77561FB8 for ; Tue, 12 Jul 2022 00:13:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1657584837; x=1689120837; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JZxZdCVM9VdvZ5C9SB8NDFeX/+e0lgtKOLXXi+obFWY=; b=X/JU5D5qKQuzgd3Yspqeu+oIYTUauZAJd+k+IQy2eUmuhvWGGesgeaAr 0JjlvRZIhgRu0V6B1BkFPRFky3aWwCqxOHlM7XmK5Kiu5dS7kEeI6m4yu b6caj933kGQinC52Nu9aq0c/lAm9jIQCn/J1UglAF8ANhXHrVKZEk1IxU PoW1fkVvIWNufjl1qH2utRbKu3myVvX4bvvXw63p64wZ8UYhe+X6i+BqH wE0mRaTjnvyRSJURhWVZOXGzLotCzpgf5sGUikASSOYdx0BoS76SJK2G0 8iOLStqDchT35ecrRQBAH/gKam9bvXcmnc2+ZSPcElSV0X0GxuzBE9Qqb g==; X-IronPort-AV: E=McAfee;i="6400,9594,10405"; a="264589943" X-IronPort-AV: E=Sophos;i="5.92,264,1650956400"; d="scan'208";a="264589943" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2022 17:13:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,264,1650956400"; d="scan'208";a="592445746" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga007.jf.intel.com with ESMTP; 11 Jul 2022 17:13:54 -0700 From: Lu Baolu To: Joerg Roedel Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 10/25] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Date: Tue, 12 Jul 2022 08:08:53 +0800 Message-Id: <20220712000908.3431936-11-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220712000908.3431936-1-baolu.lu@linux.intel.com> References: <20220712000908.3431936-1-baolu.lu@linux.intel.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The disable_dmar_iommu() is called when IOMMU initialization fails or the IOMMU is hot-removed from the system. In both cases, there is no need to clear the IOMMU translation data structures for devices. On the initialization path, the device probing only happens after the IOMMU is initialized successfully, hence there're no translation data structures. On the hot-remove path, there is no real use case where the IOMMU is hot-removed, but the devices that it manages are still alive in the system. The translation data structures were torn down during device release, hence there's no need to repeat it in IOMMU hot-remove path either. This removes the unnecessary code and only leaves a check. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-3-baolu.lu@linux.intel.com --- drivers/iommu/intel/pasid.h | 1 + drivers/iommu/intel/iommu.c | 21 +++++++-------------- 2 files changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h index bf5b937848b4..20c54e50f533 100644 --- a/drivers/iommu/intel/pasid.h +++ b/drivers/iommu/intel/pasid.h @@ -39,6 +39,7 @@ * only and pass-through transfer modes. */ #define FLPT_DEFAULT_DID 1 +#define NUM_RESERVED_DID 2 /* * The SUPERVISOR_MODE flag indicates a first level translation which diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 3b6571681bdd..43aaec5bdd84 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1716,23 +1716,16 @@ static int iommu_init_domains(struct intel_iommu *iommu) static void disable_dmar_iommu(struct intel_iommu *iommu) { - struct device_domain_info *info, *tmp; - unsigned long flags; - if (!iommu->domain_ids) return; - spin_lock_irqsave(&device_domain_lock, flags); - list_for_each_entry_safe(info, tmp, &device_domain_list, global) { - if (info->iommu != iommu) - continue; - - if (!info->dev || !info->domain) - continue; - - __dmar_remove_one_dev_info(info); - } - spin_unlock_irqrestore(&device_domain_lock, flags); + /* + * All iommu domains must have been detached from the devices, + * hence there should be no domain IDs in use. + */ + if (WARN_ON(bitmap_weight(iommu->domain_ids, cap_ndoms(iommu->cap)) + > NUM_RESERVED_DID)) + return; if (iommu->gcmd & DMA_GCMD_TE) iommu_disable_translation(iommu); -- 2.25.1