@@ -727,11 +727,24 @@ int iommufd_access_set_ioas(struct iommufd_access *access, u32 ioas_id)
iommufd_ref_to_users(obj);
}
+ /*
+ * Set ioas to NULL to block any further iommufd_access_pin_pages().
+ * iommufd_access_unpin_pages() can continue using access->ioas_unpin.
+ */
+ access->ioas = NULL;
+
+ if (access->ops->unmap) {
+ mutex_unlock(&access->ioas_lock);
+ access->ops->unmap(access->data, 0, ULONG_MAX);
+ mutex_lock(&access->ioas_lock);
+ }
+
if (cur_ioas) {
iopt_remove_access(&cur_ioas->iopt, access);
refcount_dec(&cur_ioas->obj.users);
}
+ access->ioas_unpin = new_ioas;
access->ioas = new_ioas;
mutex_unlock(&access->ioas_lock);
@@ -805,11 +818,11 @@ void iommufd_access_unpin_pages(struct iommufd_access *access,
return;
mutex_lock(&access->ioas_lock);
- if (!access->ioas) {
+ if (!access->ioas_unpin) {
mutex_unlock(&access->ioas_lock);
return;
}
- iopt = &access->ioas->iopt;
+ iopt = &access->ioas_unpin->iopt;
down_read(&iopt->iova_rwsem);
iopt_for_each_contig_area(&iter, area, iopt, iova, last_iova)
@@ -312,6 +312,7 @@ struct iommufd_access {
struct iommufd_object obj;
struct iommufd_ctx *ictx;
struct iommufd_ioas *ioas;
+ struct iommufd_ioas *ioas_unpin;
struct mutex ioas_lock;
const struct iommufd_access_ops *ops;
void *data;
Support an access->ioas replacement in iommufd_access_set_ioas(), which sets the access->ioas to NULL provisionally so that any further incoming iommufd_access_pin_pages() callback can be blocked. Then, call access->ops->unmap() to clean up the entire iopt. To allow an iommufd_access_unpin_pages() callback to happen via this unmap() call, add an ioas_unpin pointer so the unpin routine won't be affected by the "access->ioas = NULL" trick above. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com> --- drivers/iommu/iommufd/device.c | 17 +++++++++++++++-- drivers/iommu/iommufd/iommufd_private.h | 1 + 2 files changed, 16 insertions(+), 2 deletions(-)