net: thunderx: 80xx BGX0 configuration changes

On 80xx only one lane of DLM0 and DLM1 (of BGX0) can be used
, so even though lmac count may be 2 but LMAC1 should use
serdes lane of DLM1. Since it's not possible to distinguish
80xx from 81xx as PCI devid are same, this patch adds this
config support by replying on what firmware configures the
lmacs with.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/thunder/thunder_bgx.c

@@ -970,11 +970,25 @@ static void bgx_set_lmac_config(struct bgx *bgx, u8 idx)
 		lmac_set_training(bgx, lmac, lmac->lmacid);
 		lmac_set_lane2sds(bgx, lmac);
 
-		/* Set LMAC type of other lmac on same DLM i.e LMAC 1/3 */
 		olmac = &bgx->lmac[idx + 1];
-		olmac->lmac_type = lmac->lmac_type;
+		/*  Check if other LMAC on the same DLM is already configured by
+		 *  firmware, if so use the same config or else set as same, as
+		 *  that of LMAC 0/2.
+		 *  This check is needed as on 80xx only one lane of each of the
+		 *  DLM of BGX0 is used, so have to rely on firmware for
+		 *  distingushing 80xx from 81xx.
+		 */
+		cmr_cfg = bgx_reg_read(bgx, idx + 1, BGX_CMRX_CFG);
+		lmac_type = (u8)((cmr_cfg >> 8) & 0x07);
+		lane_to_sds = (u8)(cmr_cfg & 0xFF);
+		if ((lmac_type == 0) && (lane_to_sds == 0xE4)) {
+			olmac->lmac_type = lmac->lmac_type;
+			lmac_set_lane2sds(bgx, olmac);
+		} else {
+			olmac->lmac_type = lmac_type;
+			olmac->lane_to_sds = lane_to_sds;
+		}
 		lmac_set_training(bgx, olmac, olmac->lmacid);
-		lmac_set_lane2sds(bgx, olmac);
 	}
 }