myri10ge: optimize 4k-boundary check when stocking rx pages

Small optimization to the code which checks to see if we'd cross
a 4K boundary when stocking RX ring.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Andrew Gallatin <gallatin@myri.com>
Signed-off-by: Guillaume Morin <guillaume@morinfr.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index aae2ddb5d827..676c513e12fc 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -77,7 +77,7 @@
 #include "myri10ge_mcp.h"
 #include "myri10ge_mcp_gen_header.h"
 
-#define MYRI10GE_VERSION_STR "1.5.1-1.453"
+#define MYRI10GE_VERSION_STR "1.5.2-1.459"
 
 MODULE_DESCRIPTION("Myricom 10G driver (10GbE)");
 MODULE_AUTHOR("Maintainer: help@myri.com");
@@ -1200,6 +1200,9 @@ myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
 {
         struct page *page;
         int idx;
+#if MYRI10GE_ALLOC_SIZE > 4096
+        int end_offset;
+#endif
 
         if (unlikely(rx->watchdog_needed && !watchdog))
                 return;
@@ -1241,9 +1244,9 @@ myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
 
 #if MYRI10GE_ALLOC_SIZE > 4096
                 /* don't cross a 4KB boundary */
-                if ((rx->page_offset >> 12) !=
-                    ((rx->page_offset + bytes - 1) >> 12))
-                        rx->page_offset = (rx->page_offset + 4096) & ~4095;
+                end_offset = rx->page_offset + bytes - 1;
+                if ((unsigned)(rx->page_offset ^ end_offset) > 4095)
+                        rx->page_offset = end_offset & ~4095;
 #endif
                 rx->fill_cnt++;