sfc: Enable RX DMA scattering where possible

[deliverable/linux.git] / drivers / net / ethernet / sfc / efx.c

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index f8013c3ea37cd45fefc3e70cba9fcc3f1f7ca91b..1213af5024d18ff6a92cb2c222460429ed94db45 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -88,8 +88,6 @@ const char *const efx_reset_type_names[] = {
        [RESET_TYPE_MC_FAILURE]         = "MC_FAILURE",
 };
 
-#define EFX_MAX_MTU (9 * 1024)
-
 /* Reset workqueue. If any NIC has a hardware failure then a reset will be
  * queued onto this work queue. This is not a per-nic work queue, because
  * efx_reset_work() acquires the rtnl lock, so resets are naturally serialised.
@@ -627,9 +625,11 @@ fail:
  */
 static void efx_start_datapath(struct efx_nic *efx)
 {
+       bool old_rx_scatter = efx->rx_scatter;
        struct efx_tx_queue *tx_queue;
        struct efx_rx_queue *rx_queue;
        struct efx_channel *channel;
+       size_t rx_buf_len;
 
        /* Calculate the rx buffer allocation parameters required to
         * support the current MTU, including padding for header
@@ -638,8 +638,32 @@ static void efx_start_datapath(struct efx_nic *efx)
        efx->rx_dma_len = (efx->type->rx_buffer_hash_size +
                           EFX_MAX_FRAME_LEN(efx->net_dev->mtu) +
                           efx->type->rx_buffer_padding);
-       efx->rx_buffer_order = get_order(sizeof(struct efx_rx_page_state) +
-                                        EFX_PAGE_IP_ALIGN + efx->rx_dma_len);
+       rx_buf_len = (sizeof(struct efx_rx_page_state) +
+                     EFX_PAGE_IP_ALIGN + efx->rx_dma_len);
+       if (rx_buf_len <= PAGE_SIZE) {
+               efx->rx_scatter = false;
+               efx->rx_buffer_order = 0;
+               if (rx_buf_len <= PAGE_SIZE / 2)
+                       efx->rx_buffer_truesize = PAGE_SIZE / 2;
+               else
+                       efx->rx_buffer_truesize = PAGE_SIZE;
+       } else if (efx->type->can_rx_scatter) {
+               BUILD_BUG_ON(sizeof(struct efx_rx_page_state) +
+                            EFX_PAGE_IP_ALIGN + EFX_RX_USR_BUF_SIZE >
+                            PAGE_SIZE / 2);
+               efx->rx_scatter = true;
+               efx->rx_dma_len = EFX_RX_USR_BUF_SIZE;
+               efx->rx_buffer_order = 0;
+               efx->rx_buffer_truesize = PAGE_SIZE / 2;
+       } else {
+               efx->rx_scatter = false;
+               efx->rx_buffer_order = get_order(rx_buf_len);
+               efx->rx_buffer_truesize = PAGE_SIZE << efx->rx_buffer_order;
+       }
+
+       /* RX filters also have scatter-enabled flags */
+       if (efx->rx_scatter != old_rx_scatter)
+               efx_filter_update_rx_scatter(efx);
 
        /* We must keep at least one descriptor in a TX ring empty.
         * We could avoid this when the queue size does not exactly
@@ -661,7 +685,7 @@ static void efx_start_datapath(struct efx_nic *efx)
                        efx_nic_generate_fill_event(rx_queue);
                }
 
-               WARN_ON(channel->rx_pkt != NULL);
+               WARN_ON(channel->rx_pkt_n_frags);
        }
 
        if (netif_device_present(efx->net_dev))