NET: stmmac: align DMA stuff to largest cache line length

BugLink: http://bugs.launchpad.net/bugs/1815234
[ Upstream commit 9939a46d90c6c76f4533d534dbadfa7b39dc6acc ]

As for today STMMAC_ALIGN macro (which is used to align DMA stuff)
relies on L1 line length (L1_CACHE_BYTES).
This isn't correct in case of system with several cache levels
which might have L1 cache line length smaller than L2 line. This
can lead to sharing one cache line between DMA buffer and other
data, so we can lose this data while invalidate DMA buffer before
DMA transaction.

Fix that by using SMP_CACHE_BYTES instead of L1_CACHE_BYTES for
aligning.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 15217c68dee2043bf5d2e9b27fdc3a3f13b8d2c8..a89bc7f999e3bd27c0b5f3f5fc7af6ef3193d712 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -51,7 +51,7 @@
 #include <linux/of_mdio.h>
 #include "dwmac1000.h"
 
-#define STMMAC_ALIGN(x)        L1_CACHE_ALIGN(x)
+#define        STMMAC_ALIGN(x)         __ALIGN_KERNEL(x, SMP_CACHE_BYTES)
 #define        TSO_MAX_BUFF_SIZE       (SZ_16K - 1)
 
 /* Module parameters */