3 files changed, 19 insertions, 5 deletions

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 999289bb2eb9..39e4cb39de29 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -643,9 +643,11 @@ static void efx_start_datapath(struct efx_nic *efx)
                 efx->rx_scatter = false;
                 efx->rx_buffer_order = 0;
         } else if (efx->type->can_rx_scatter) {
+                BUILD_BUG_ON(EFX_RX_USR_BUF_SIZE % L1_CACHE_BYTES);
                 BUILD_BUG_ON(sizeof(struct efx_rx_page_state) +
-                             NET_IP_ALIGN + EFX_RX_USR_BUF_SIZE >
-                             PAGE_SIZE / 2);
+                             2 * ALIGN(NET_IP_ALIGN + EFX_RX_USR_BUF_SIZE,
+                                       EFX_RX_BUF_ALIGNMENT) >
+                             PAGE_SIZE);
                 efx->rx_scatter = true;
                 efx->rx_dma_len = EFX_RX_USR_BUF_SIZE;
                 efx->rx_buffer_order = 0;
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 5efddf3c66e9..39d6bd77f015 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -72,8 +72,20 @@
 /* Maximum possible MTU the driver supports */
 #define EFX_MAX_MTU (9 * 1024)
 
-/* Size of an RX scatter buffer.  Small enough to pack 2 into a 4K page. */
-#define EFX_RX_USR_BUF_SIZE 1824
+/* Size of an RX scatter buffer.  Small enough to pack 2 into a 4K page,
+ * and should be a multiple of the cache line size.
+ */
+#define EFX_RX_USR_BUF_SIZE     (2048 - 256)
+
+/* If possible, we should ensure cache line alignment at start and end
+ * of every buffer.  Otherwise, we just need to ensure 4-byte
+ * alignment of the network header.
+ */
+#if NET_IP_ALIGN == 0
+#define EFX_RX_BUF_ALIGNMENT    L1_CACHE_BYTES
+#else
+#define EFX_RX_BUF_ALIGNMENT    4
+#endif
 
 /* Forward declare Precision Time Protocol (PTP) support structure. */
 struct efx_ptp_data;
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 99f70dd55fc8..a7dfe36cabf4 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -94,7 +94,7 @@ static inline void efx_sync_rx_buffer(struct efx_nic *efx,
 void efx_rx_config_page_split(struct efx_nic *efx)
 {
         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + NET_IP_ALIGN,
-                                      L1_CACHE_BYTES);
+                                      EFX_RX_BUF_ALIGNMENT);
         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
                  efx->rx_page_buf_step);