vfio/type1: unmap cleanup

Minor changes in vfio_dma_do_unmap to improve readability, which also
simplify the subsequent unmap-all patch.  No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0b4deda..e31c926 100644 (file)
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1074,34 +1074,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
 {
        struct vfio_dma *dma, *dma_last = NULL;
        size_t unmapped = 0, pgsize;
-       int ret = 0, retries = 0;
+       int ret = -EINVAL, retries = 0;
        unsigned long pgshift;
+       dma_addr_t iova = unmap->iova;
+       unsigned long size = unmap->size;
 
        mutex_lock(&iommu->lock);
 
        pgshift = __ffs(iommu->pgsize_bitmap);
        pgsize = (size_t)1 << pgshift;
 
-       if (unmap->iova & (pgsize - 1)) {
-               ret = -EINVAL;
+       if (iova & (pgsize - 1))
                goto unlock;
-       }
 
-       if (!unmap->size || unmap->size & (pgsize - 1)) {
-               ret = -EINVAL;
+       if (!size || size & (pgsize - 1))
                goto unlock;
-       }
 
-       if (unmap->iova + unmap->size - 1 < unmap->iova ||
-           unmap->size > SIZE_MAX) {
-               ret = -EINVAL;
+       if (iova + size - 1 < iova || size > SIZE_MAX)
                goto unlock;
-       }
 
        /* When dirty tracking is enabled, allow only min supported pgsize */
        if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
            (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) {
-               ret = -EINVAL;
                goto unlock;
        }
 
@@ -1139,20 +1133,18 @@ again:
         * mappings within the range.
         */
        if (iommu->v2) {
-               dma = vfio_find_dma(iommu, unmap->iova, 1);
-               if (dma && dma->iova != unmap->iova) {
-                       ret = -EINVAL;
+               dma = vfio_find_dma(iommu, iova, 1);
+               if (dma && dma->iova != iova)
                        goto unlock;
-               }
-               dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
-               if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
-                       ret = -EINVAL;
+
+               dma = vfio_find_dma(iommu, iova + size - 1, 0);
+               if (dma && dma->iova + dma->size != iova + size)
                        goto unlock;
-               }
        }
 
-       while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
-               if (!iommu->v2 && unmap->iova > dma->iova)
+       ret = 0;
+       while ((dma = vfio_find_dma(iommu, iova, size))) {
+               if (!iommu->v2 && iova > dma->iova)
                        break;
                /*
                 * Task with same address space who mapped this iova range is
@@ -1190,7 +1182,7 @@ again:
 
                if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
                        ret = update_user_bitmap(bitmap->data, iommu, dma,
-                                                unmap->iova, pgsize);
+                                                iova, pgsize);
                        if (ret)
                                break;
                }