From:   "Matthew Wilcox (Oracle)" <willy@infradead.org>
To:     linux-mm@kvack.org
Cc:     "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        John Hubbard <jhubbard@nvidia.com>,
        Christoph Hellwig <hch@infradead.org>,
        William Kucharski <william.kucharski@oracle.com>,
        linux-kernel@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca>
Subject: [PATCH v2 03/28] gup: Change the calling convention for compound_range_next()
Date:   Mon, 10 Jan 2022 04:23:41 +0000
Message-Id: <20220110042406.499429-4-willy@infradead.org>
In-Reply-To: <20220110042406.499429-1-willy@infradead.org>
References: <20220110042406.499429-1-willy@infradead.org>
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Return the head page instead of storing it to a passed parameter.
Pass the start page directly instead of passing a pointer to it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/gup.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 86f8d843de72..3c93d2fdf4da 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -229,21 +229,20 @@ void unpin_user_page(struct page *page)
 }
 EXPORT_SYMBOL(unpin_user_page);
 
-static inline void compound_range_next(unsigned long i, unsigned long npages,
-				       struct page **list, struct page **head,
-				       unsigned int *ntails)
+static inline struct page *compound_range_next(unsigned long i,
+		unsigned long npages, struct page *start, unsigned int *ntails)
 {
 	struct page *next, *page;
 	unsigned int nr = 1;
 
-	next = *list + i;
+	next = start + i;
 	page = compound_head(next);
 	if (PageCompound(page) && compound_order(page) >= 1)
 		nr = min_t(unsigned int,
 			   page + compound_nr(page) - next, npages - i);
 
-	*head = page;
 	*ntails = nr;
+	return page;
 }
 
 static inline void compound_next(unsigned long i, unsigned long npages,
@@ -355,7 +354,7 @@ void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
 	unsigned int ntails;
 
 	for (index = 0; index < npages; index += ntails) {
-		compound_range_next(index, npages, &page, &head, &ntails);
+		head = compound_range_next(index, npages, page, &ntails);
 		if (make_dirty && !PageDirty(head))
 			set_page_dirty_lock(head);
 		put_compound_head(head, ntails, FOLL_PIN);
-- 
2.33.0