PERFORCE change 40978 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=40978

Change 40978 by sam at sam_ebb on 2003/10/31 08:30:54

	minor changes for forthcoming HAL update: verify the
	ABI checksum, print the mac, phy, and radio h/w revs
	at attach time (maybe should be under bootverbose)

Affected files ...

.. //depot/projects/netperf/sys/dev/ath/if_ath.c#29 edit

Differences ...

==== //depot/projects/netperf/sys/dev/ath/if_ath.c#29 (text+ko) ====

@@ -174,6 +174,33 @@
 #define	DPRINTF2(X)
 #endif
 
+/*
+ * Calculate a "checksum" that the driver can use to
+ * check for ABI compatibility.  We just sum the offsets
+ * of all the function pointers which are assumed to
+ * start with ah_getRateTable and continue sequentially
+ * to the end of the structure.  If a new method is added
+ * or moved this will be detected.  This will not, however
+ * catch methods being moved around or some number added
+ * while an equal number are replaced, or arguments being
+ * changed, or lots of other things.
+ *
+ * This is stopgap.  Improvements are welcome.
+ */
+static u_int32_t
+ath_calcsum(void)
+{
+	u_int32_t sum = 0;
+	u_int32_t off;
+
+	off = offsetof(struct ath_hal, ah_getRateTable);
+	while (off < sizeof(struct ath_hal)) {
+		sum += off;
+		off += sizeof(void (*)(void));
+	}
+	return sum;
+}
+
 int
 ath_attach(u_int16_t devid, struct ath_softc *sc)
 {
@@ -196,6 +223,23 @@
 		error = ENXIO;
 		goto bad;
 	}
+	if (ah->ah_checksum != ath_calcsum()) {
+		if_printf(ifp, "HAL ABI mismatch detected (%u != %u)\n",
+			ah->ah_checksum, ath_calcsum());
+		error = ENXIO;
+		goto bad;
+	}
+	if_printf(ifp, "mac %d.%d phy %d.%d",
+		ah->ah_macVersion, ah->ah_macRev,
+		ah->ah_phyRev >> 4, ah->ah_phyRev & 0xf);
+	if (ah->ah_analog5GhzRev)
+		printf(" 5ghz radio %d.%d",
+			ah->ah_analog5GhzRev >> 4, ah->ah_analog5GhzRev & 0xf);
+	if (ah->ah_analog2GhzRev)
+		printf(" 2ghz radio %d.%d",
+			ah->ah_analog2GhzRev >> 4, ah->ah_analog2GhzRev & 0xf);
+	printf("\n");
+
 	sc->sc_ah = ah;
 	sc->sc_invalid = 0;	/* ready to go, enable interrupt handling */