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Thu, 14 May 2020 17:11:17 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:10:00 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:16 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:16 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:15 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:09 +0000 From: Kirti Wankhede To: , Subject: [PATCH Kernel v20 2/8] vfio iommu: Remove atomicity of ref_count of pinned pages Date: Fri, 15 May 2020 02:07:41 +0530 Message-ID: <1589488667-9683-3-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; 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Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia Reviewed-by: Eric Auger Reviewed-by: Cornelia Huck --- drivers/vfio/vfio_iommu_type1.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index a0c60f895b24..fa735047b04d 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -112,7 +112,7 @@ struct vfio_pfn { struct rb_node node; dma_addr_t iova; /* Device address */ unsigned long pfn; /* Host pfn */ - atomic_t ref_count; + unsigned int ref_count; }; struct vfio_regions { @@ -233,7 +233,7 @@ static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova, vpfn->iova = iova; vpfn->pfn = pfn; - atomic_set(&vpfn->ref_count, 1); + vpfn->ref_count = 1; vfio_link_pfn(dma, vpfn); return 0; } @@ -251,7 +251,7 @@ static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova); if (vpfn) - atomic_inc(&vpfn->ref_count); + vpfn->ref_count++; return vpfn; } @@ -259,7 +259,8 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn) { int ret = 0; - if (atomic_dec_and_test(&vpfn->ref_count)) { + vpfn->ref_count--; + if (!vpfn->ref_count) { ret = put_pfn(vpfn->pfn, dma->prot); vfio_remove_from_pfn_list(dma, vpfn); }