[PATCH v2 07/34] mm: Convert ptlock_alloc() to use ptdescs

["Vishal Moola (Oracle)" <vishal.moola@gmail.com>]

This removes some direct accesses to struct page, working towards
splitting out struct ptdesc from struct page.

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
 include/linux/mm.h | 6 +++---
 mm/memory.c        | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 62c1635a9d44..565da5f39376 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2786,7 +2786,7 @@ static inline void ptdesc_clear(void *x)
 #if USE_SPLIT_PTE_PTLOCKS
 #if ALLOC_SPLIT_PTLOCKS
 void __init ptlock_cache_init(void);
-extern bool ptlock_alloc(struct page *page);
+bool ptlock_alloc(struct ptdesc *ptdesc);
 extern void ptlock_free(struct page *page);
 
 static inline spinlock_t *ptlock_ptr(struct page *page)
@@ -2798,7 +2798,7 @@ static inline void ptlock_cache_init(void)
 {
 }
 
-static inline bool ptlock_alloc(struct page *page)
+static inline bool ptlock_alloc(struct ptdesc *ptdesc)
 {
 	return true;
 }
@@ -2828,7 +2828,7 @@ static inline bool ptlock_init(struct page *page)
 	 * slab code uses page->slab_cache, which share storage with page->ptl.
 	 */
 	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
-	if (!ptlock_alloc(page))
+	if (!ptlock_alloc(page_ptdesc(page)))
 		return false;
 	spin_lock_init(ptlock_ptr(page));
 	return true;
diff --git a/mm/memory.c b/mm/memory.c
index 5e2c6b1fc00e..ba0dd1b2d616 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5939,14 +5939,14 @@ void __init ptlock_cache_init(void)
 			SLAB_PANIC, NULL);
 }
 
-bool ptlock_alloc(struct page *page)
+bool ptlock_alloc(struct ptdesc *ptdesc)
 {
 	spinlock_t *ptl;
 
 	ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL);
 	if (!ptl)
 		return false;
-	page->ptl = ptl;
+	ptdesc->ptl = ptl;
 	return true;
 }
 
-- 
2.39.2