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| author | Kirti Wankhede <kwankhede@nvidia.com> | 2020-05-28 22:30:48 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2020-05-28 23:53:21 +0200 |
| commit | 6581708586c812460ea4798216d9dd2897ad105c (patch) | |
| tree | bb47b15b72e57676769c1cd908a5129b73b271b6 /drivers/vfio | |
| parent | vfio: UAPI for migration interface for device state (diff) | |
| download | linux-6581708586c812460ea4798216d9dd2897ad105c.tar.xz linux-6581708586c812460ea4798216d9dd2897ad105c.zip | |
vfio iommu: Remove atomicity of ref_count of pinned pages
vfio_pfn.ref_count is always updated while holding iommu->lock, using
atomic variable is overkill.
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/vfio_iommu_type1.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 4a4cb7cd86b2..e0de3337fa2a 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); } |