mm: restore documentation for __free_pages()

JIRA: https://issues.redhat.com/browse/RHEL-78202

Conflicts:
- conflicts due to missing mm series "Allocate and free frozen pages"

commit 3091b61
Author: Matthew Wilcox (Oracle) <willy@infradead.org>
Date:   Wed Jun 4 20:03:26 2025 +0100

    mm: restore documentation for __free_pages()

    The documentation was converted to be for ___free_pages(), which doesn't
    need documentation as it's static.

    Link: https://lkml.kernel.org/r/20250604190327.814086-1-willy@infradead.org
    Fixes: 8c57b68 (mm, bpf: Introduce free_pages_nolock())
    Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
    Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
    Cc: Alexei Starovoitov <ast@kernel.org>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Gregory Bell <grbell@redhat.com>

Author: Gbell26

mm/page_alloc.c

@@ -4872,11 +4872,27 @@ unsigned long get_zeroed_page_noprof(gfp_t gfp_mask)
 }
 EXPORT_SYMBOL(get_zeroed_page_noprof);
 
+static void ___free_pages(struct page *page, unsigned int order,
+			  fpi_t fpi_flags)
+{
+	/* get PageHead before we drop reference */
+	int head = PageHead(page);
+	struct alloc_tag *tag = pgalloc_tag_get(page);
+
+	if (put_page_testzero(page))
+		__free_unref_page(page, order, fpi_flags);
+	else if (!head) {
+		pgalloc_tag_sub_pages(tag, (1 << order) - 1);
+		while (order-- > 0)
+			__free_unref_page(page + (1 << order), order,
+					fpi_flags);
+	}
+}
+
 /**
- * ___free_pages - Free pages allocated with alloc_pages().
+ * __free_pages - Free pages allocated with alloc_pages().
  * @page: The page pointer returned from alloc_pages().
  * @order: The order of the allocation.
- * @fpi_flags: Free Page Internal flags.
  *
  * This function can free multi-page allocations that are not compound
  * pages.  It does not check that the @order passed in matches that of
@@ -4893,22 +4909,6 @@ EXPORT_SYMBOL(get_zeroed_page_noprof);
  * Context: May be called in interrupt context or while holding a normal
  * spinlock, but not in NMI context or while holding a raw spinlock.
  */
-static void ___free_pages(struct page *page, unsigned int order,
-			  fpi_t fpi_flags)
-{
-	/* get PageHead before we drop reference */
-	int head = PageHead(page);
-	struct alloc_tag *tag = pgalloc_tag_get(page);
-
-	if (put_page_testzero(page))
-		__free_unref_page(page, order, fpi_flags);
-	else if (!head) {
-		pgalloc_tag_sub_pages(tag, (1 << order) - 1);
-		while (order-- > 0)
-			__free_unref_page(page + (1 << order), order,
-					fpi_flags);
-	}
-}
 void __free_pages(struct page *page, unsigned int order)
 {
 	___free_pages(page, order, FPI_NONE);