mm/huge_memory: convert has_hwpoisoned into a pure folio flag

Patch series "mm: hugetlb+THP folio and migration cleanups", v2.

Some cleanups around more folio conversion and migration handling that I
collected working on random stuff.


This patch (of 6):

Let's stop setting it on pages, there is no need to anymore.

Link: https://lkml.kernel.org/r/20250113131611.2554758-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: davidhildenbrand

include/linux/page-flags.h

@@ -906,11 +906,9 @@ TESTPAGEFLAG_FALSE(TransCompound, transcompound)
  *
  * This flag is set by hwpoison handler.  Cleared by THP split or free page.
  */
-PAGEFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
-	TESTSCFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
+FOLIO_FLAG(has_hwpoisoned, FOLIO_SECOND_PAGE)
 #else
-PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned)
-	TESTSCFLAG_FALSE(HasHWPoisoned, has_hwpoisoned)
+FOLIO_FLAG_FALSE(has_hwpoisoned)
 #endif
 
 /*

mm/huge_memory.c

@@ -3290,7 +3290,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
 	/* lock lru list/PageCompound, ref frozen by page_ref_freeze */
 	lruvec = folio_lruvec_lock(folio);
 
-	ClearPageHasHWPoisoned(head);
+	folio_clear_has_hwpoisoned(folio);
 
 	for (i = nr - new_nr; i >= new_nr; i -= new_nr) {
 		struct folio *tail;