From a59faac5f2347e4b2a4275275495bdc0146ae76e Mon Sep 17 00:00:00 2001
From: briggs <briggs@openbsd.org>
Date: Fri, 25 Apr 1997 03:29:14 +0000
Subject: [PATCH] A couple of performance improvements from Denny Gentry
 <denny1@home.com>

---
 sys/arch/mac68k/dev/if_sn.c    | 33 +++++++++++++++++++++------------
 sys/arch/mac68k/dev/if_snvar.h | 21 ++++++++++++---------
 2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/sys/arch/mac68k/dev/if_sn.c b/sys/arch/mac68k/dev/if_sn.c
index 3bd38797bf8..e65ad212d58 100644
--- a/sys/arch/mac68k/dev/if_sn.c
+++ b/sys/arch/mac68k/dev/if_sn.c
@@ -1,5 +1,5 @@
 /*	$NetBSD: if_sn.c,v 1.7 1997/03/20 17:47:51 scottr Exp $	*/
-/*	$OpenBSD: if_sn.c,v 1.21 1997/04/18 11:58:34 briggs Exp $	*/
+/*	$OpenBSD: if_sn.c,v 1.22 1997/04/25 03:29:15 briggs Exp $	*/
 
 /*
  * National Semiconductor  SONIC Driver
@@ -176,14 +176,6 @@ snsetup(sc)
 
 	p = (unsigned char *)SOALIGN(sc, p);
 
-	for (i = 0; i < NRDA; i++) {
-		sc->p_rda[i] = (void *) p;
-		sc->v_rda[i] = kvtop(p);
-		p += RXPKT_SIZE(sc);
-	}
-
-	p = (unsigned char *)SOALIGN(sc, p);
-
 	for (i = 0; i < NTDA; i++) {
 		struct mtd *mtdp = &sc->mtda[i];
 		mtdp->mtd_txp = (void *)p;
@@ -195,16 +187,33 @@ snsetup(sc)
 
 	if ((p - pp) > NBPG) {
 		printf ("%s: sizeof RRA (%ld) + CDA (%ld) +"
-			"RDA (%ld) + TDA (%ld) > NBPG (%d). Punt!\n",
+			"TDA (%ld) > NBPG (%d). Punt!\n",
 			sc->sc_dev.dv_xname,
 			(ulong)sc->p_cda - (ulong)sc->p_rra[0],
-			(ulong)sc->p_rda[0] - (ulong)sc->p_cda,
-			(ulong)sc->mtda[0].mtd_txp - (ulong)sc->p_rda[0],
+			(ulong)sc->mtda[0].mtd_txp - (ulong)sc->p_cda,
 			(ulong)p - (ulong)sc->mtda[0].mtd_txp,
 			NBPG);
 		return(1);
 	}
 
+	p = pp + NBPG;
+	pp = p;
+
+	if ((NRDA * RXPKT_SIZE(sc)) > NBPG) {
+		printf ("%s: sizeof NRDA (%d) > NBPG (%d). Punt!\n",
+			sc->sc_dev.dv_xname,
+			NRDA * RXPKT_SIZE(sc), NBPG);
+		return (1);
+	}
+
+	for (i = 0; i < NRDA; i++) {
+		sc->p_rda[i] = (void *) p;
+		sc->v_rda[i] = kvtop(p);
+		p += RXPKT_SIZE(sc);
+	}
+
+	p = (unsigned char *)SOALIGN(sc, p);
+
 	p = pp + NBPG;
 
 	for (i = 0; i < NRBA; i++) {
diff --git a/sys/arch/mac68k/dev/if_snvar.h b/sys/arch/mac68k/dev/if_snvar.h
index 5f3bd9bf5b2..9d0abe3bd83 100644
--- a/sys/arch/mac68k/dev/if_snvar.h
+++ b/sys/arch/mac68k/dev/if_snvar.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: if_snvar.h,v 1.6 1997/04/23 00:28:22 gene Exp $       */
+/*      $OpenBSD: if_snvar.h,v 1.7 1997/04/25 03:29:14 briggs Exp $       */
 
 /*
  * Copyright (c) 1991   Algorithmics Ltd (http://www.algor.co.uk)
@@ -40,19 +40,22 @@
 
 /*
  * buffer sizes in 32 bit mode
- * 1 TXpkt is 4 hdr words + (3 * FRAGMAX) + 1 link word
- * FRAGMAX == 16 => 54 words == 216 bytes
+ * 1 TXpkt is 4 hdr words + (3 * FRAGMAX) + 1 link word == 23 words == 92 bytes
  *
  * 1 RxPkt is 7 words == 28 bytes
  * 1 Rda   is 4 words == 16 bytes
+ *
+ * The CDA is 17 words == 68 bytes
+ *
+ * total space in page 0 = NTDA * 92 + NRRA * 16 + NRDA * 28 + 68
  */
 
 #define NRBA    8		/* # receive buffers < NRRA */
 #define RBAMASK (NRBA-1)
-#define NRDA    NRBA*4
-#define NTDA    4		/* # transmit descriptors */
-#define NRRA    32		/* # receive resource descriptors */
-#define RRAMASK (NRRA-1)	/* the reason why it must be power of two */
+#define NRDA    146
+#define NTDA    8		/* # transmit descriptors */
+#define NRRA    16		/* # receive resource descriptors */
+#define RRAMASK (NRRA-1)	/* the reason why NRRA must be power of two */
 
 #define FCSSIZE 4		/* size of FCS appended to packets */
 
@@ -66,10 +69,10 @@
 /*
  * transmit buffer area
  */
-#define NTXB    10      /* Number of xmit buffers */
+#define NTXB    NTDA	/* Number of xmit buffers */
 #define TXBSIZE 1536    /* 6*2^8 -- the same size as the 8390 TXBUF */
 
-#define	SN_NPAGES	1 + 8 + 5
+#define	SN_NPAGES	2 + 8 + 4
 
 /*
  * Statistics collected over time
-- 
2.20.1