thunderx: enable page recycling for non-XDP case

[ Upstream commit b3e208069477588c06f4d5d986164b435bb06e6d ]

Commit 773225388dae15e72790 ("net: thunderx: Optimize page recycling for XDP")
added code to nicvf_alloc_page() that inadvertently disables receive buffer
page recycling for the non-XDP case by always NULL'ng the page pointer.

This patch corrects two if-conditionals to allow for the recycling of non-XDP
mode pages by only setting the page pointer to NULL when the page is not ready
for recycling.

Fixes: 773225388dae ("net: thunderx: Optimize page recycling for XDP")
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
index fcaf18f..ade1ff3 100644 (file)
--- a/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_queues.c
@@ -105,20 +105,19 @@ static inline struct pgcache *nicvf_alloc_page(struct nicvf *nic,
        /* Check if page can be recycled */
        if (page) {
                ref_count = page_ref_count(page);
-               /* Check if this page has been used once i.e 'put_page'
-                * called after packet transmission i.e internal ref_count
-                * and page's ref_count are equal i.e page can be recycled.
+               /* This page can be recycled if internal ref_count and page's
+                * ref_count are equal, indicating that the page has been used
+                * once for packet transmission. For non-XDP mode, internal
+                * ref_count is always '1'.
                 */
-               if (rbdr->is_xdp && (ref_count == pgcache->ref_count))
-                       pgcache->ref_count--;
-               else
-                       page = NULL;
-
-               /* In non-XDP mode, page's ref_count needs to be '1' for it
-                * to be recycled.
-                */
-               if (!rbdr->is_xdp && (ref_count != 1))
+               if (rbdr->is_xdp) {
+                       if (ref_count == pgcache->ref_count)
+                               pgcache->ref_count--;
+                       else
+                               page = NULL;
+               } else if (ref_count != 1) {
                        page = NULL;
+               }
        }
 
        if (!page) {