Revert r271504. A new patch to solve this issue will be made.

Suggested by:	adrian @

4 files changed, 23 insertions, 98 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 5e9b776..017af33 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -423,52 +423,6 @@ if_grow(void)
 }
 
 /*
- * Compute the least common value of two "if_hw_tsomax" values:
- */
-u_int
-if_hw_tsomax_common(u_int a, u_int b)
-{
-	u_int a_bytes = IF_HW_TSOMAX_GET_BYTES(a);
-	u_int a_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(a);
-	u_int a_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(a);
-	u_int b_bytes = IF_HW_TSOMAX_GET_BYTES(b);
-	u_int b_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(b);
-	u_int b_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(b);
-
-	return (IF_HW_TSOMAX_BUILD_VALUE(min(a_bytes, b_bytes),
-	    min(a_frag_count, b_frag_count),
-	    min(a_frag_size, b_frag_size)));
-}
-
-/*
- * Range check the "if_hw_tsomax" value:
- */
-u_int
-if_hw_tsomax_range_check(u_int a)
-{
-	u_int a_bytes = IF_HW_TSOMAX_GET_BYTES(a);
-	u_int a_frag_count = IF_HW_TSOMAX_GET_FRAG_COUNT(a);
-	u_int a_frag_size = IF_HW_TSOMAX_GET_FRAG_SIZE(a);
-
-	/* round down to nearest 4 bytes */
-	a_bytes &= 0xFFFC;
-
-	/* use default, if zero */
-	if (a_bytes == 0)
-		a_bytes = IF_HW_TSOMAX_DEFAULT_BYTES;
-
-	/* use default, if zero */
-	if (a_frag_count == 0)
-		a_frag_count = IF_HW_TSOMAX_DEFAULT_FRAG_COUNT;
-
-	/* use default, if zero */
-	if (a_frag_size == 0)
-		a_frag_size = IF_HW_TSOMAX_DEFAULT_FRAG_SIZE;
-
-	return (IF_HW_TSOMAX_BUILD_VALUE(a_bytes, a_frag_count, a_frag_size));
-}
-
-/*
  * Allocate a struct ifnet and an index for an interface.  A layer 2
  * common structure will also be allocated if an allocation routine is
  * registered for the passed type.
@@ -491,7 +445,6 @@ if_alloc(u_char type)
 	ifp->if_index = idx;
 	ifp->if_type = type;
 	ifp->if_alloctype = type;
-	ifp->if_hw_tsomax = IF_HW_TSOMAX_DEFAULT_VALUE();
 	if (if_com_alloc[type] != NULL) {
 		ifp->if_l2com = if_com_alloc[type](type, ifp);
 		if (ifp->if_l2com == NULL) {
@@ -704,9 +657,16 @@ if_attach_internal(struct ifnet *ifp, int vmove)
 		TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
 		/* Reliably crash if used uninitialized. */
 		ifp->if_broadcastaddr = NULL;
-		/* range check TSO value */
-		ifp->if_hw_tsomax =
-		    if_hw_tsomax_range_check(ifp->if_hw_tsomax);
+
+#if defined(INET) || defined(INET6)
+		/* Initialize to max value. */
+		if (ifp->if_hw_tsomax == 0)
+			ifp->if_hw_tsomax = min(IP_MAXPACKET, 32 * MCLBYTES -
+			    (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN));
+		KASSERT(ifp->if_hw_tsomax <= IP_MAXPACKET &&
+		    ifp->if_hw_tsomax >= IP_MAXPACKET / 8,
+		    ("%s: tsomax outside of range", __func__));
+#endif
 	}
 #ifdef VIMAGE
 	else {
diff --git a/sys/net/if_lagg.c b/sys/net/if_lagg.c
index e7cfb3c..8d53526 100644
--- a/sys/net/if_lagg.c
+++ b/sys/net/if_lagg.c
@@ -445,7 +445,11 @@ lagg_capabilities(struct lagg_softc *sc)
 	struct lagg_port *lp;
 	int cap = ~0, ena = ~0;
 	u_long hwa = ~0UL;
-	u_int hw_tsomax = IF_HW_TSOMAX_DEFAULT_VALUE();
+#if defined(INET) || defined(INET6)
+	u_int hw_tsomax = IP_MAXPACKET;	/* Initialize to the maximum value. */
+#else
+	u_int hw_tsomax = ~0;	/* if_hw_tsomax is only for INET/INET6, but.. */
+#endif
 
 	LAGG_WLOCK_ASSERT(sc);
 
@@ -454,9 +458,10 @@ lagg_capabilities(struct lagg_softc *sc)
 		cap &= lp->lp_ifp->if_capabilities;
 		ena &= lp->lp_ifp->if_capenable;
 		hwa &= lp->lp_ifp->if_hwassist;
-		/* Set to the common value of the lagg ports. */
-		hw_tsomax = if_hw_tsomax_common(hw_tsomax,
-		    lp->lp_ifp->if_hw_tsomax);
+		/* Set to the minimum value of the lagg ports. */
+		if (lp->lp_ifp->if_hw_tsomax < hw_tsomax &&
+		    lp->lp_ifp->if_hw_tsomax > 0)
+			hw_tsomax = lp->lp_ifp->if_hw_tsomax;
 	}
 	cap = (cap == ~0 ? 0 : cap);
 	ena = (ena == ~0 ? 0 : ena);
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index af83713..09f41b8 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -120,43 +120,6 @@ typedef int (*if_transmit_fn_t)(if_t, struct mbuf *);
 typedef	uint64_t (*if_get_counter_t)(if_t, ifnet_counter);
 
 /*
- * Macros defining how to decode the "if_hw_tsomax" field:
- */
-#define	IF_HW_TSOMAX_GET_BYTES(x)		\
-    ((uint16_t)(x))	/* 32..65535 */
-
-#define	IF_HW_TSOMAX_GET_FRAG_COUNT(x)		\
-    ((uint8_t)((x) >> 16))	/* 1..255 */
-
-#define	IF_HW_TSOMAX_GET_FRAG_SIZE(x)		\
-    ((uint8_t)((x) >> 24))	/* 12..16 */
-
-/*
- * The following macro defines how to build the "if_hw_tsomax"
- * field. The "bytes" field has unit 1 bytes and declares the maximum
- * number of bytes which can be transferred by a single transmit
- * offload, TSO, job. The "bytes" field is rounded down to the neares
- * 4 bytes to avoid having the hardware do unaligned memory
- * accesses. The "frag_count" field has unit 1 fragment and declares
- * the maximum number of fragments a TSO job can contain. The
- * "frag_size" field has unit logarithm in base 2 of the actual value
- * in bytes and declares the maximum size of a fragment.
- */
-#define	IF_HW_TSOMAX_BUILD_VALUE(bytes, frag_count, frag_size)	\
-    (((bytes) & 0xFFFC) | (((frag_count) & 0xFF) << 16) |	\
-    (((frag_size) & 0xFF) << 24))
-
-#define	IF_HW_TSOMAX_DEFAULT_BYTES (65536 - 4)
-#define	IF_HW_TSOMAX_DEFAULT_FRAG_COUNT 255
-#define	IF_HW_TSOMAX_DEFAULT_FRAG_SIZE 16
-
-#define	IF_HW_TSOMAX_DEFAULT_VALUE()		\
-    IF_HW_TSOMAX_BUILD_VALUE(			\
-    IF_HW_TSOMAX_DEFAULT_BYTES,			\
-    IF_HW_TSOMAX_DEFAULT_FRAG_COUNT,		\
-    IF_HW_TSOMAX_DEFAULT_FRAG_SIZE)
-
-/*
  * Structure defining a network interface.
  *
  * Size ILP32:  592 (approx)
@@ -259,7 +222,8 @@ struct ifnet {
 	if_get_counter_t if_get_counter; /* get counter values */
 
 	/* Stuff that's only temporary and doesn't belong here. */
-	u_int	if_hw_tsomax;		/* TSO burst length limits.
+	u_int	if_hw_tsomax;		/* tso burst length limit, the minimum
+					 * is (IP_MAXPACKET / 8).
 					 * XXXAO: Have to find a better place
 					 * for it eventually. */
 	/*
@@ -644,10 +608,6 @@ void if_setioctlfn(if_t ifp, int (*)(if_t, u_long, caddr_t));
 void if_setstartfn(if_t ifp, void (*)(if_t));
 void if_settransmitfn(if_t ifp, if_transmit_fn_t);
 void if_setqflushfn(if_t ifp, if_qflush_fn_t);
-
-/* "if_hw_tsomax" related functions */
-u_int if_hw_tsomax_common(u_int, u_int);
-u_int if_hw_tsomax_range_check(u_int);
  
 /* Revisit the below. These are inline functions originally */
 int drbr_inuse_drv(if_t ifp, struct buf_ring *br);
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index b7ccb61..5a5e712 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1557,8 +1557,8 @@ vlan_capabilities(struct ifvlan *ifv)
 	 * propagate the hardware-assisted flag. TSO on VLANs
 	 * does not necessarily require hardware VLAN tagging.
 	 */
-	ifp->if_hw_tsomax = if_hw_tsomax_common(ifp->if_hw_tsomax,
-	    p->if_hw_tsomax);
+	if (p->if_hw_tsomax > 0)
+		ifp->if_hw_tsomax = p->if_hw_tsomax;
 	if (p->if_capabilities & IFCAP_VLAN_HWTSO)
 		ifp->if_capabilities |= p->if_capabilities & IFCAP_TSO;
 	if (p->if_capenable & IFCAP_VLAN_HWTSO) {