Avoid long term pinning for Coherent device type pages. This could interfere with their own device memory manager. For now, we are just returning error for PIN_LONGTERM Coherent device type pages. Eventually, these type of pages will get migrated to system memory, once the device migration pages support is added.
Signed-off-by: Alex Sierra alex.sierra@amd.com Acked-by: Felix Kuehling Felix.Kuehling@amd.com Reviewed-by: Alistair Poppple apopple@nvidia.com --- mm/gup.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/mm/gup.c b/mm/gup.c index f0af462ac1e2..f596b932d7d7 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1864,6 +1864,12 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, * If we get a movable page, since we are going to be pinning * these entries, try to move them out if possible. */ + if (is_dev_private_or_coherent_page(head)) { + WARN_ON_ONCE(is_device_private_page(head)); + ret = -EFAULT; + goto unpin_pages; + } + if (!is_pinnable_page(head)) { if (PageHuge(head)) { if (!isolate_huge_page(head, &movable_page_list)) @@ -1894,6 +1900,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, if (list_empty(&movable_page_list) && !isolation_error_count) return nr_pages;
+unpin_pages: if (gup_flags & FOLL_PIN) { unpin_user_pages(pages, nr_pages); } else {