Merge tag 'asoc-v3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-next

ASoC: Updates for v3.13

 - Further work on the dmaengine helpers, including support for
   configuring the parameters for DMA by reading the capabilities of the
   DMA controller which removes some guesswork and magic numbers fromm
   drivers.
 - A refresh of the documentation.
 - Conversions of many drivers to direct regmap API usage in order to
   allow the ASoC level register I/O code to be removed, this will
   hopefully be completed by v3.14.
 - Support for using async register I/O in DAPM, reducing the time taken
   to implement power transitions on systems that support it.

1 files changed, 16 insertions, 1 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b49579c7f2a5..0b7656e804d1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -653,6 +653,7 @@ static void free_huge_page(struct page *page)
 	BUG_ON(page_count(page));
 	BUG_ON(page_mapcount(page));
 	restore_reserve = PagePrivate(page);
+	ClearPagePrivate(page);
 
 	spin_lock(&hugetlb_lock);
 	hugetlb_cgroup_uncharge_page(hstate_index(h),
@@ -695,8 +696,22 @@ static void prep_compound_gigantic_page(struct page *page, unsigned long order)
 	/* we rely on prep_new_huge_page to set the destructor */
 	set_compound_order(page, order);
 	__SetPageHead(page);
+	__ClearPageReserved(page);
 	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
 		__SetPageTail(p);
+		/*
+		 * For gigantic hugepages allocated through bootmem at
+		 * boot, it's safer to be consistent with the not-gigantic
+		 * hugepages and clear the PG_reserved bit from all tail pages
+		 * too.  Otherwse drivers using get_user_pages() to access tail
+		 * pages may get the reference counting wrong if they see
+		 * PG_reserved set on a tail page (despite the head page not
+		 * having PG_reserved set).  Enforcing this consistency between
+		 * head and tail pages allows drivers to optimize away a check
+		 * on the head page when they need know if put_page() is needed
+		 * after get_user_pages().
+		 */
+		__ClearPageReserved(p);
 		set_page_count(p, 0);
 		p->first_page = page;
 	}
@@ -1329,9 +1344,9 @@ static void __init gather_bootmem_prealloc(void)
 #else
 		page = virt_to_page(m);
 #endif
-		__ClearPageReserved(page);
 		WARN_ON(page_count(page) != 1);
 		prep_compound_huge_page(page, h->order);
+		WARN_ON(PageReserved(page));
 		prep_new_huge_page(h, page, page_to_nid(page));
 		/*
 		 * If we had gigantic hugepages allocated at boot time, we need