diff options
Diffstat (limited to 'drivers/iommu/iommufd/io_pagetable.c')
| -rw-r--r-- | drivers/iommu/iommufd/io_pagetable.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c index e0ae72b9e67f..724c4c574241 100644 --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -458,6 +458,7 @@ static int iopt_unmap_iova_range(struct io_pagetable *iopt, unsigned long start, { struct iopt_area *area; unsigned long unmapped_bytes = 0; + unsigned int tries = 0; int rc = -ENOENT; /* @@ -484,19 +485,26 @@ again: goto out_unlock_iova; } + if (area_first != start) + tries = 0; + /* * num_accesses writers must hold the iova_rwsem too, so we can * safely read it under the write side of the iovam_rwsem * without the pages->mutex. */ if (area->num_accesses) { + size_t length = iopt_area_length(area); + start = area_first; area->prevent_access = true; up_write(&iopt->iova_rwsem); up_read(&iopt->domains_rwsem); - iommufd_access_notify_unmap(iopt, area_first, - iopt_area_length(area)); - if (WARN_ON(READ_ONCE(area->num_accesses))) + + iommufd_access_notify_unmap(iopt, area_first, length); + /* Something is not responding to unmap requests. */ + tries++; + if (WARN_ON(tries > 100)) return -EDEADLOCK; goto again; } |