Add Rx checksum offloading support for Yukon FE+ and Yukon Extreme.

These controllers use newer descriptor format and the new descriptor
format uses status LE to indicate the status of checksum. Rx
checksummed value used in previous controllers were very cryptic
and I failed to understand how to use them. In addition most
controllers in previous generations had Rx checksum offloading bug.

While I'm here introduce a MSK_FLAG_NORX_CSUM flag to bypass
checking Rx checksum offloading as Yukon FE+ A0 has status LE bug.

2 files changed, 67 insertions, 8 deletions

diff --git a/sys/dev/msk/if_msk.c b/sys/dev/msk/if_msk.c
index 4a98b64..1147040 100644
--- a/sys/dev/msk/if_msk.c
+++ b/sys/dev/msk/if_msk.c
@@ -258,8 +258,8 @@ static void msk_intr_hwerr(struct msk_softc *);
 #ifndef __NO_STRICT_ALIGNMENT
 static __inline void msk_fixup_rx(struct mbuf *);
 #endif
-static void msk_rxeof(struct msk_if_softc *, uint32_t, int);
-static void msk_jumbo_rxeof(struct msk_if_softc *, uint32_t, int);
+static void msk_rxeof(struct msk_if_softc *, uint32_t, uint32_t, int);
+static void msk_jumbo_rxeof(struct msk_if_softc *, uint32_t, uint32_t, int);
 static void msk_txeof(struct msk_if_softc *, int);
 static int msk_encap(struct msk_if_softc *, struct mbuf **);
 static void msk_tx_task(void *, int);
@@ -267,6 +267,7 @@ static void msk_start(struct ifnet *);
 static int msk_ioctl(struct ifnet *, u_long, caddr_t);
 static void msk_set_prefetch(struct msk_softc *, int, bus_addr_t, uint32_t);
 static void msk_set_rambuffer(struct msk_if_softc *);
+static void msk_set_tx_stfwd(struct msk_if_softc *);
 static void msk_init(void *);
 static void msk_init_locked(struct msk_if_softc *);
 static void msk_stop(struct msk_if_softc *);
@@ -991,12 +992,17 @@ msk_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 			else
 				ifp->if_hwassist &= ~MSK_CSUM_FEATURES;
 		}
+		if ((mask & IFCAP_RXCSUM) != 0 &&
+		    (IFCAP_RXCSUM & ifp->if_capabilities) != 0)
+			ifp->if_capenable ^= IFCAP_RXCSUM;
 		if ((mask & IFCAP_VLAN_HWTAGGING) != 0 &&
 		    (IFCAP_VLAN_HWTAGGING & ifp->if_capabilities) != 0) {
 			ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
 			msk_setvlan(sc_if, ifp);
 		}
-
+		if ((mask & IFCAP_VLAN_HWCSUM) != 0 &&
+		    (IFCAP_VLAN_HWCSUM & ifp->if_capabilities) != 0)
+			ifp->if_capenable ^= IFCAP_VLAN_HWCSUM;
 		if ((mask & IFCAP_TSO4) != 0 &&
 		    (IFCAP_TSO4 & ifp->if_capabilities) != 0) {
 			ifp->if_capenable ^= IFCAP_TSO4;
@@ -1492,6 +1498,13 @@ msk_attach(device_t dev)
 	 * make Rx checksum offload work on Yukon II hardware.
 	 */
 	ifp->if_capabilities = IFCAP_TXCSUM | IFCAP_TSO4;
+	/*
+	 * Enable Rx checksum offloading if controller support new
+	 * descriptor format.
+	 */
+	if ((sc_if->msk_flags & MSK_FLAG_DESCV2) != 0 && 
+	    (sc_if->msk_flags & MSK_FLAG_NORX_CSUM) == 0)
+		ifp->if_capabilities |= IFCAP_RXCSUM;
 	ifp->if_hwassist = MSK_CSUM_FEATURES | CSUM_TSO;
 	ifp->if_capenable = ifp->if_capabilities;
 	ifp->if_ioctl = msk_ioctl;
@@ -1535,6 +1548,13 @@ msk_attach(device_t dev)
 		 * for VLAN interface.
 		 */
         	ifp->if_capabilities |= IFCAP_VLAN_HWTAGGING;
+		/*
+		 * Enable Rx checksum offloading for VLAN taggedd frames
+		 * if controller support new descriptor format.
+		 */
+		if ((sc_if->msk_flags & MSK_FLAG_DESCV2) != 0 && 
+		    (sc_if->msk_flags & MSK_FLAG_NORX_CSUM) == 0)
+			ifp->if_capabilities |= IFCAP_VLAN_HWCSUM;
 	}
 	ifp->if_capenable = ifp->if_capabilities;
 
@@ -1711,7 +1731,8 @@ mskc_attach(device_t dev)
 			 * Just pass received frames to upper stack with
 			 * minimal test and let upper stack handle them.
 			 */
-			sc->msk_pflags |= MSK_FLAG_NOHWVLAN | MSK_FLAG_NORXCHK;
+			sc->msk_pflags |= MSK_FLAG_NOHWVLAN |
+			    MSK_FLAG_NORXCHK | MSK_FLAG_NORX_CSUM;
 		}
 		break;
 	case CHIP_ID_YUKON_XL:
@@ -2942,7 +2963,8 @@ msk_fixup_rx(struct mbuf *m)
 #endif
 
 static void
-msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
+msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, uint32_t control,
+    int len)
 {
 	struct mbuf *m;
 	struct ifnet *ifp;
@@ -2994,6 +3016,18 @@ msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 			msk_fixup_rx(m);
 #endif
 		ifp->if_ipackets++;
+		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0 &&
+		    (control & (CSS_IPV4 | CSS_IPFRAG)) == CSS_IPV4) {
+			m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
+			if ((control & CSS_IPV4_CSUM_OK) != 0)
+				m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
+			if ((control & (CSS_TCP | CSS_UDP)) != 0 &&
+			    (control & (CSS_TCPUDP_CSUM_OK)) != 0) {
+				m->m_pkthdr.csum_flags |= CSUM_DATA_VALID |
+				    CSUM_PSEUDO_HDR;
+				m->m_pkthdr.csum_data = 0xffff;
+			}
+		}
 		/* Check for VLAN tagged packets. */
 		if ((status & GMR_FS_VLAN) != 0 &&
 		    (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) != 0) {
@@ -3010,7 +3044,8 @@ msk_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 }
 
 static void
-msk_jumbo_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
+msk_jumbo_rxeof(struct msk_if_softc *sc_if, uint32_t status, uint32_t control,
+    int len)
 {
 	struct mbuf *m;
 	struct ifnet *ifp;
@@ -3051,6 +3086,18 @@ msk_jumbo_rxeof(struct msk_if_softc *sc_if, uint32_t status, int len)
 			msk_fixup_rx(m);
 #endif
 		ifp->if_ipackets++;
+		if ((ifp->if_capenable & IFCAP_RXCSUM) != 0 &&
+		    (control & (CSS_IPV4 | CSS_IPFRAG)) == CSS_IPV4) {
+			m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED;
+			if ((control & CSS_IPV4_CSUM_OK) != 0)
+				m->m_pkthdr.csum_flags |= CSUM_IP_VALID;
+			if ((control & (CSS_TCP | CSS_UDP)) != 0 &&
+			    (control & (CSS_TCPUDP_CSUM_OK)) != 0) {
+				m->m_pkthdr.csum_flags |= CSUM_DATA_VALID |
+				    CSUM_PSEUDO_HDR;
+				m->m_pkthdr.csum_data = 0xffff;
+			}
+		}
 		/* Check for VLAN tagged packets. */
 		if ((status & GMR_FS_VLAN) != 0 &&
 		    (ifp->if_capenable & IFCAP_VLAN_HWTAGGING) != 0) {
@@ -3379,9 +3426,9 @@ msk_handle_events(struct msk_softc *sc)
 		case OP_RXSTAT:
 			if (sc_if->msk_framesize >
 			    (MCLBYTES - MSK_RX_BUF_ALIGN))
-				msk_jumbo_rxeof(sc_if, status, len);
+				msk_jumbo_rxeof(sc_if, status, control, len);
 			else
-				msk_rxeof(sc_if, status, len);
+				msk_rxeof(sc_if, status, control, len);
 			rxprog++;
 			/*
 			 * Because there is no way to sync single Rx LE
diff --git a/sys/dev/msk/if_mskreg.h b/sys/dev/msk/if_mskreg.h
index 8f5797b..958bf78 100644
--- a/sys/dev/msk/if_mskreg.h
+++ b/sys/dev/msk/if_mskreg.h
@@ -2255,8 +2255,19 @@ struct msk_stat_desc {
 #define OP_PUTIDX	0x70000000
 
 #define	STLE_OP_MASK	0xff000000
+#define	STLE_CSS_MASK	0x00ff0000
 #define	STLE_LEN_MASK	0x0000ffff
 
+/* CSS defined in status LE(valid for descriptor V2 format). */
+#define	CSS_TCPUDP_CSUM_OK	0x00800000
+#define	CSS_UDP			0x00400000
+#define	CSS_TCP			0x00200000
+#define	CSS_IPFRAG		0x00100000
+#define	CSS_IPV6		0x00080000
+#define	CSS_IPV4_CSUM_OK	0x00040000
+#define	CSS_IPV4		0x00020000
+#define	CSS_PORT		0x00010000
+
 /* Descriptor Bit Definition */
 /*	TxCtrl		Transmit Buffer Control Field */
 /*	RxCtrl		Receive  Buffer Control Field */
@@ -2505,6 +2516,7 @@ struct msk_if_softc {
 #define	MSK_FLAG_AUTOTX_CSUM	0x0080
 #define	MSK_FLAG_NOHWVLAN	0x0100
 #define	MSK_FLAG_NORXCHK	0x0200
+#define	MSK_FLAG_NORX_CSUM	0x0400
 #define	MSK_FLAG_SUSPEND	0x2000
 #define	MSK_FLAG_DETACH		0x4000
 #define	MSK_FLAG_LINK		0x8000