Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751572AbbKJB4l (ORCPT ); Mon, 9 Nov 2015 20:56:41 -0500 Received: from mail-pa0-f66.google.com ([209.85.220.66]:35791 "EHLO mail-pa0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbbKJB4k (ORCPT ); Mon, 9 Nov 2015 20:56:40 -0500 From: Peng Fan To: will.deacon@arm.com Cc: joro@8bytes.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Peng Fan Subject: [RFC V3] iommu: arm-smmu: correct group reference count Date: Tue, 10 Nov 2015 09:56:26 +0800 Message-Id: <1447120586-17847-1-git-send-email-van.freenix@gmail.com> X-Mailer: git-send-email 1.8.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2178 Lines: 68 The basic flow for add a device: arm_smmu_add_device |->iommu_group_get_for_dev |->iommu_group_get return group; (1) |->ops->device_group : Init/increase reference count to/by 1. |->iommu_group_add_device : Increase reference count by 1. return group (2) |->return 0; Since we are adding one device, the flow is (2) and the group reference count will be increased by 2. So, we need to add iommu_group_put at the end of arm_smmu_add_device to decrease the count by 1. Signed-off-by: Peng Fan Cc: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 7 ++++++- drivers/iommu/arm-smmu.c | 2 ++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 4e5118a..ac333ee 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1825,8 +1825,10 @@ static int arm_smmu_add_device(struct device *dev) pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, &sid); for (i = 0; i < smmu_group->num_sids; ++i) { /* If we already know about this SID, then we're done */ - if (smmu_group->sids[i] == sid) + if (smmu_group->sids[i] == sid) { + iommu_group_put(group); return 0; + } } /* Check the SID is in range of the SMMU and our stream table */ @@ -1855,6 +1857,9 @@ static int arm_smmu_add_device(struct device *dev) /* Add the new SID */ sids[smmu_group->num_sids - 1] = sid; smmu_group->sids = sids; + + iommu_group_put(group); + return 0; out_put_group: diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 47dc7a7..af6afce 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1357,6 +1357,8 @@ static int arm_smmu_add_device(struct device *dev) if (IS_ERR(group)) return PTR_ERR(group); + iommu_group_put(group); + return 0; } -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/