cxgb4: Handle clip return values

Add a warn message when clip table overflows. If clip table isn't
allocated, return from cxgb4_clip_release() to avoid panic.
Disable offload if clip isn't enabled in the hardware.

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/clip_tbl.c

@@ -118,6 +118,11 @@ int cxgb4_clip_get(const struct net_device *dev, const u32 *lip, u8 v6)
 			ret = clip6_get_mbox(dev, (const struct in6_addr *)lip);
 			if (ret) {
 				write_unlock_bh(&ctbl->lock);
+				dev_err(adap->pdev_dev,
+					"CLIP FW cmd failed with error %d, "
+					"Connections using %pI6c wont be "
+					"offloaded",
+					ret, ce->addr6.sin6_addr.s6_addr);
 				return ret;
 			}
 		} else {
@@ -127,6 +132,9 @@ int cxgb4_clip_get(const struct net_device *dev, const u32 *lip, u8 v6)
 		}
 	} else {
 		write_unlock_bh(&ctbl->lock);
+		dev_info(adap->pdev_dev, "CLIP table overflow, "
+			 "Connections using %pI6c wont be offloaded",
+			 (void *)lip);
 		return -ENOMEM;
 	}
 	write_unlock_bh(&ctbl->lock);
@@ -146,6 +154,9 @@ void cxgb4_clip_release(const struct net_device *dev, const u32 *lip, u8 v6)
 	int hash;
 	int ret = -1;
 
+	if (!ctbl)
+		return;
+
 	hash = clip_addr_hash(ctbl, addr, v6);
 
 	read_lock_bh(&ctbl->lock);

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

@@ -4865,15 +4865,25 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 
 #if IS_ENABLED(CONFIG_IPV6)
-	adapter->clipt = t4_init_clip_tbl(adapter->clipt_start,
-					  adapter->clipt_end);
-	if (!adapter->clipt) {
-		/* We tolerate a lack of clip_table, giving up
-		 * some functionality
+	if ((CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5) &&
+	    (!(t4_read_reg(adapter, LE_DB_CONFIG_A) & ASLIPCOMPEN_F))) {
+		/* CLIP functionality is not present in hardware,
+		 * hence disable all offload features
 		 */
 		dev_warn(&pdev->dev,
-			 "could not allocate Clip table, continuing\n");
+			 "CLIP not enabled in hardware, continuing\n");
 		adapter->params.offload = 0;
+	} else {
+		adapter->clipt = t4_init_clip_tbl(adapter->clipt_start,
+						  adapter->clipt_end);
+		if (!adapter->clipt) {
+			/* We tolerate a lack of clip_table, giving up
+			 * some functionality
+			 */
+			dev_warn(&pdev->dev,
+				 "could not allocate Clip table, continuing\n");
+			adapter->params.offload = 0;
+		}
 	}
 #endif
 	if (is_offload(adapter) && tid_init(&adapter->tids) < 0) {

drivers/net/ethernet/chelsio/cxgb4/t4_regs.h

@@ -2802,6 +2802,10 @@
 #define HASHEN_V(x) ((x) << HASHEN_S)
 #define HASHEN_F    HASHEN_V(1U)
 
+#define ASLIPCOMPEN_S    17
+#define ASLIPCOMPEN_V(x) ((x) << ASLIPCOMPEN_S)
+#define ASLIPCOMPEN_F    ASLIPCOMPEN_V(1U)
+
 #define REQQPARERR_S    16
 #define REQQPARERR_V(x) ((x) << REQQPARERR_S)
 #define REQQPARERR_F    REQQPARERR_V(1U)