From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753403AbcGTMtn (ORCPT ); Wed, 20 Jul 2016 08:49:43 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:14154 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752507AbcGTMth (ORCPT ); Wed, 20 Jul 2016 08:49:37 -0400 From: To: , , , , , CC: , , , , , , , , , , , , , , , , , , , , , Honghui Zhang Subject: [RFC PATCH] iommu: create direct_mapping after device attached Date: Wed, 20 Jul 2016 20:49:21 +0800 Message-ID: <1469018961-16367-1-git-send-email-honghui.zhang@mediatek.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Honghui Zhang For mtk iommu, the domain_finalize was called in device attatch, the mtk iommu iopgt ops was allocated and initialized in domain_finalize, the iommu_group_create_direct_mappings would call the map interface to implement the map. If it's earlier than device attach, there would be NULL dereference. Move the iommu_group_create_direct_mappings call after device attached. Signed-off-by: Honghui Zhang --- drivers/iommu/iommu.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3000051..24c671c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -427,14 +427,19 @@ rename: dev->iommu_group = group; - iommu_group_create_direct_mappings(group, dev); - mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); if (group->domain) __iommu_attach_device(group->domain, dev); mutex_unlock(&group->mutex); + /* + * For some iommu driver like mtk iommu, the map callback was assigned + * after device attached. The direct_mappings would call iommu map and + * dereference NULL if it's called earlier than attach_device. + */ + iommu_group_create_direct_mappings(group, dev); + /* Notify any listeners about change to group. */ blocking_notifier_call_chain(&group->notifier, IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev); -- 1.8.1.1.dirty