emx: Allow user to specify the number of RX ring to use

Default value is 0, which means auto (based on # of cpus in the system)

diff --git a/sys/dev/netif/emx/if_emx.c b/sys/dev/netif/emx/if_emx.c
index cd3d2e3..d00f126 100644 (file)
--- a/sys/dev/netif/emx/if_emx.c
+++ b/sys/dev/netif/emx/if_emx.c
@@ -285,6 +285,7 @@ static int  emx_int_throttle_ceil = EMX_DEFAULT_ITR;
 static int     emx_rxd = EMX_DEFAULT_RXD;
 static int     emx_txd = EMX_DEFAULT_TXD;
 static int     emx_smart_pwr_down = 0;
+static int     emx_rxr = 0;
 
 /* Controls whether promiscuous also shows bad packets */
 static int     emx_debug_sbp = 0;
@@ -294,6 +295,7 @@ static int  emx_msi_enable = 1;
 
 TUNABLE_INT("hw.emx.int_throttle_ceil", &emx_int_throttle_ceil);
 TUNABLE_INT("hw.emx.rxd", &emx_rxd);
+TUNABLE_INT("hw.emx.rxr", &emx_rxr);
 TUNABLE_INT("hw.emx.txd", &emx_txd);
 TUNABLE_INT("hw.emx.smart_pwr_down", &emx_smart_pwr_down);
 TUNABLE_INT("hw.emx.sbp", &emx_debug_sbp);
@@ -530,10 +532,13 @@ emx_attach(device_t dev)
        sc->hw.mac.report_tx_early = 1;
 
        /* Calculate # of RX rings */
-       if (ncpus > 1)
-               sc->rx_ring_cnt = EMX_NRX_RING;
-       else
-               sc->rx_ring_cnt = 1;
+       sc->rx_ring_cnt = device_getenv_int(dev, "rxr", emx_rxr);
+       if (sc->rx_ring_cnt <= 0 || sc->rx_ring_cnt > EMX_NRX_RING) {
+               if (ncpus > 1)
+                       sc->rx_ring_cnt = EMX_NRX_RING;
+               else
+                       sc->rx_ring_cnt = 1;
+       }
        sc->rx_ring_inuse = sc->rx_ring_cnt;
 
        /* Allocate RX/TX rings' busdma(9) stuffs */