sfc: Split MAC stats DMA initiation and completion

From: Steve Hodgson <shodgson@solarflare.com>

Currently we initiate MAC stats DMA and busy-wait for completion when
stats are requested.  We can improve on this with a periodic timer to
initiate and poll for stats, and opportunistically poll when stats are
requested.

Since efx_nic::stats_disable_count and efx_stats_{disable,enable}()
are Falcon-specific, rename them and move them accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/net/sfc/falcon_xmac.c b/drivers/net/sfc/falcon_xmac.c
index cf24513900e7..e57545de60ff 100644
--- a/drivers/net/sfc/falcon_xmac.c
+++ b/drivers/net/sfc/falcon_xmac.c
@@ -60,9 +60,13 @@ static void falcon_setup_xaui(struct efx_nic *efx)
 
 int falcon_reset_xaui(struct efx_nic *efx)
 {
+        struct falcon_nic_data *nic_data = efx->nic_data;
         efx_oword_t reg;
         int count;
 
+        /* Don't fetch MAC statistics over an XMAC reset */
+        WARN_ON(nic_data->stats_disable_count == 0);
+
         /* Start reset sequence */
         EFX_POPULATE_OWORD_1(reg, FRF_AB_XX_RST_XX_EN, 1);
         efx_writeo(efx, &reg, FR_AB_XX_PWR_RST);
@@ -250,6 +254,8 @@ static void falcon_check_xaui_link_up(struct efx_nic *efx, int tries)
                 /* XAUI link is expected to be down */
                 return;
 
+        falcon_stop_nic_stats(efx);
+
         while (!efx->mac_up && tries) {
                 EFX_LOG(efx, "bashing xaui\n");
                 falcon_reset_xaui(efx);
@@ -258,6 +264,8 @@ static void falcon_check_xaui_link_up(struct efx_nic *efx, int tries)
                 efx->mac_up = falcon_xaui_link_ok(efx);
                 --tries;
         }
+
+        falcon_start_nic_stats(efx);
 }
 
 static void falcon_reconfigure_xmac(struct efx_nic *efx)
@@ -276,11 +284,6 @@ static void falcon_reconfigure_xmac(struct efx_nic *efx)
 static void falcon_update_stats_xmac(struct efx_nic *efx)
 {
         struct efx_mac_stats *mac_stats = &efx->mac_stats;
-        int rc;
-
-        rc = falcon_dma_stats(efx, XgDmaDone_offset);
-        if (rc)
-                return;
 
         /* Update MAC stats from DMAed values */
         FALCON_STAT(efx, XgRxOctets, rx_bytes);