[PATCH v1 1/4] lib/test_hmm: make dmirror_atomic_map() consume a single page

[David Hildenbrand]

The caller now always passes a single page; let's simplify, and return
"0" on success.

Signed-off-by: David Hildenbrand <da...@redhat.com>
---
 lib/test_hmm.c | 33 ++++++++++-----------------------
 1 file changed, 10 insertions(+), 23 deletions(-)

diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 9e1b07a227a3..1c0a58279db9 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -706,34 +706,23 @@ static int dmirror_check_atomic(struct dmirror *dmirror, 
unsigned long start,
        return 0;
 }
 
-static int dmirror_atomic_map(unsigned long start, unsigned long end,
-                             struct page **pages, struct dmirror *dmirror)
+static int dmirror_atomic_map(unsigned long addr, struct page *page,
+               struct dmirror *dmirror)
 {
-       unsigned long pfn, mapped = 0;
-       int i;
+       void *entry;
 
        /* Map the migrated pages into the device's page tables. */
        mutex_lock(&dmirror->mutex);
 
-       for (i = 0, pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); 
pfn++, i++) {
-               void *entry;
-
-               if (!pages[i])
-                       continue;
-
-               entry = pages[i];
-               entry = xa_tag_pointer(entry, DPT_XA_TAG_ATOMIC);
-               entry = xa_store(&dmirror->pt, pfn, entry, GFP_ATOMIC);
-               if (xa_is_err(entry)) {
-                       mutex_unlock(&dmirror->mutex);
-                       return xa_err(entry);
-               }
-
-               mapped++;
+       entry = xa_tag_pointer(page, DPT_XA_TAG_ATOMIC);
+       entry = xa_store(&dmirror->pt, addr >> PAGE_SHIFT, entry, GFP_ATOMIC);
+       if (xa_is_err(entry)) {
+               mutex_unlock(&dmirror->mutex);
+               return xa_err(entry);
        }
 
        mutex_unlock(&dmirror->mutex);
-       return mapped;
+       return 0;
 }
 
 static int dmirror_migrate_finalize_and_map(struct migrate_vma *args,
@@ -803,9 +792,7 @@ static int dmirror_exclusive(struct dmirror *dmirror,
                        break;
                }
 
-               ret = dmirror_atomic_map(addr, addr + PAGE_SIZE, &page, 
dmirror);
-               if (!ret)
-                       ret = -EBUSY;
+               ret = dmirror_atomic_map(addr, page, dmirror);
                folio_unlock(folio);
                folio_put(folio);
 
-- 
2.48.1