Clean up the buffer allocation code a bit. Make sure to initialize certain

critical mbuf fields to sane values. Simplify the use of ETHER_ALIGN to
enforce payload alignment, and turn it on on the x86 as well as alpha
since it helps with NFS which wants the payload to be longword aligned
even though the hardware doesn't require it.

This fixes a problem with the ti driver causing an unaligned access trap
on the Alpha due to m_adj() sometimes not setting the alignment correctly
because of incomplete mbuf initialization.

1 files changed, 29 insertions, 19 deletions

diff --git a/sys/pci/if_ti.c b/sys/pci/if_ti.c
index 838e47a..6c4a987 100644
--- a/sys/pci/if_ti.c
+++ b/sys/pci/if_ti.c
@@ -29,7 +29,7 @@
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  *
- *	$Id: if_ti.c,v 1.10 1999/07/23 02:10:11 wpaul Exp $
+ *	$Id: if_ti.c,v 1.11 1999/07/23 16:21:43 wpaul Exp $
  */
 
 /*
@@ -131,7 +131,7 @@
 
 #if !defined(lint)
 static const char rcsid[] =
-	"$Id: if_ti.c,v 1.10 1999/07/23 02:10:11 wpaul Exp $";
+	"$Id: if_ti.c,v 1.11 1999/07/23 16:21:43 wpaul Exp $";
 #endif
 
 /*
@@ -692,7 +692,7 @@ static void ti_jref(buf, size)
 	if (sc == NULL)
 		panic("ti_jref: can't find softc pointer!");
 
-	if (size != TI_JUMBO_FRAMELEN - ETHER_ALIGN)
+	if (size != TI_JUMBO_FRAMELEN)
 		panic("ti_jref: adjusting refcount of buf of wrong size!");
 
 	/* calculate the slot this buffer belongs to */
@@ -730,7 +730,7 @@ static void ti_jfree(buf, size)
 	if (sc == NULL)
 		panic("ti_jfree: can't find softc pointer!");
 
-	if (size != TI_JUMBO_FRAMELEN - ETHER_ALIGN)
+	if (size != TI_JUMBO_FRAMELEN)
 		panic("ti_jfree: freeing buffer of wrong size!");
 
 	/* calculate the slot this buffer belongs to */
@@ -771,9 +771,7 @@ static int ti_newbuf_std(sc, i, m)
 	struct mbuf		*m_new = NULL;
 	struct ti_rx_desc	*r;
 
-	if (m != NULL) {
-		m_new = m;
-	} else {
+	if (m == NULL) {
 		MGETHDR(m_new, M_DONTWAIT, MT_DATA);
 		if (m_new == NULL) {
 			printf("ti%d: mbuf allocation failed "
@@ -788,6 +786,11 @@ static int ti_newbuf_std(sc, i, m)
 			m_freem(m_new);
 			return(ENOBUFS);
 		}
+		m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
+	} else {
+		m_new = m;
+		m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
+		m_new->m_data = m_new->m_ext.ext_buf;
 	}
 
 	m_adj(m_new, ETHER_ALIGN);
@@ -800,7 +803,7 @@ static int ti_newbuf_std(sc, i, m)
 #else
 	r->ti_flags = 0;
 #endif
-	r->ti_len = MCLBYTES - ETHER_ALIGN;
+	r->ti_len = m_new->m_len;
 	r->ti_idx = i;
 
 	return(0);
@@ -818,16 +821,20 @@ static int ti_newbuf_mini(sc, i, m)
 	struct mbuf		*m_new = NULL;
 	struct ti_rx_desc	*r;
 
-	if (m != NULL) {
-		m_new = m;
-	} else {
+	if (m == NULL) {
 		MGETHDR(m_new, M_DONTWAIT, MT_DATA);
 		if (m_new == NULL) {
 			printf("ti%d: mbuf allocation failed "
 			    "-- packet dropped!\n", sc->ti_unit);
 			return(ENOBUFS);
 		}
+		m_new->m_len = m_new->m_pkthdr.len = MHLEN;
+	} else {
+		m_new = m;
+		m_new->m_data = m_new->m_pktdat;
+		m_new->m_len = m_new->m_pkthdr.len = MHLEN;
 	}
+
 	m_adj(m_new, ETHER_ALIGN);
 	r = &sc->ti_rdata->ti_rx_mini_ring[i];
 	sc->ti_cdata.ti_rx_mini_chain[i] = m_new;
@@ -837,7 +844,7 @@ static int ti_newbuf_mini(sc, i, m)
 #ifdef TI_CSUM_OFFLOAD
 	r->ti_flags |= TI_BDFLAG_TCP_UDP_CKSUM|TI_BDFLAG_IP_CKSUM;
 #endif
-	r->ti_len = MHLEN - ETHER_ALIGN;
+	r->ti_len = m_new->m_len;
 	r->ti_idx = i;
 
 	return(0);
@@ -855,9 +862,7 @@ static int ti_newbuf_jumbo(sc, i, m)
 	struct mbuf		*m_new = NULL;
 	struct ti_rx_desc	*r;
 
-	if (m != NULL) {
-		m_new = m;
-	} else {
+	if (m == NULL) {
 		caddr_t			*buf = NULL;
 
 		/* Allocate the mbuf. */
@@ -879,13 +884,18 @@ static int ti_newbuf_jumbo(sc, i, m)
 
 		/* Attach the buffer to the mbuf. */
 		m_new->m_data = m_new->m_ext.ext_buf = (void *)buf;
-		m_new->m_data += ETHER_ALIGN;
 		m_new->m_flags |= M_EXT;
-		m_new->m_ext.ext_size = TI_JUMBO_FRAMELEN - ETHER_ALIGN;
+		m_new->m_len = m_new->m_pkthdr.len =
+		    m_new->m_ext.ext_size = TI_JUMBO_FRAMELEN;
 		m_new->m_ext.ext_free = ti_jfree;
 		m_new->m_ext.ext_ref = ti_jref;
+	} else {
+		m_new = m;
+		m_new->m_data = m_new->m_ext.ext_buf;
+		m_new->m_ext.ext_size = TI_JUMBO_FRAMELEN;
 	}
 
+	m_adj(m, ETHER_ALIGN);
 	/* Set up the descriptor. */
 	r = &sc->ti_rdata->ti_rx_jumbo_ring[i];
 	sc->ti_cdata.ti_rx_jumbo_chain[i] = m_new;
@@ -895,7 +905,7 @@ static int ti_newbuf_jumbo(sc, i, m)
 #ifdef TI_CSUM_OFFLOAD
 	r->ti_flags |= TI_BDFLAG_TCP_UDP_CKSUM|TI_BDFLAG_IP_CKSUM;
 #endif
-	r->ti_len = TI_JUMBO_FRAMELEN - ETHER_ALIGN;
+	r->ti_len = m_new->m_len;
 	r->ti_idx = i;
 
 	return(0);
@@ -1412,7 +1422,7 @@ static int ti_gibinit(sc)
 	rcb = &sc->ti_rdata->ti_info.ti_jumbo_rx_rcb;
 	TI_HOSTADDR(rcb->ti_hostaddr) =
 	    vtophys(&sc->ti_rdata->ti_rx_jumbo_ring);
-	rcb->ti_max_len = TI_JUMBO_FRAMELEN - ETHER_ALIGN;
+	rcb->ti_max_len = TI_JUMBO_FRAMELEN;
 	rcb->ti_flags = 0;
 #ifdef TI_CSUM_OFFLOAD
 	rcb->ti_flags |= TI_RCB_FLAG_TCP_UDP_CKSUM|TI_RCB_FLAG_IP_CKSUM;