mm: introduce page_size()
Patch series "Make working with compound pages easier", v2.
These three patches add three helpers and convert the appropriate
places to use them.
This patch (of 3):
It's unnecessarily hard to find out the size of a potentially huge page.
Replace 'PAGE_SIZE << compound_order(page)' with page_size(page).
Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index c2f1af3..fa8fbb8f 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -977,7 +977,7 @@ static int xsk_mmap(struct file *file, struct socket *sock,
/* Matches the smp_wmb() in xsk_init_queue */
smp_rmb();
qpg = virt_to_head_page(q->ring);
- if (size > (PAGE_SIZE << compound_order(qpg)))
+ if (size > page_size(qpg))
return -EINVAL;
pfn = virt_to_phys(q->ring) >> PAGE_SHIFT;
