if_eqos_starfive: Read MAC address from device tree

u-boot/opensbi determines the ethernet MAC address from ROM and passes
it to the OS in the device tree. This change sets the correct MAC
address from this source. This prevents the eqos class driver from
generating random MAC addresses at each boot.

Tested on Starfive VisionFive 2, riscv64 SBC.

Reviewed by:	mhorne
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D56782

sys/dev/eqos/if_eqos_starfive.c

@@ -17,6 +17,7 @@
 #include <sys/socket.h>
 #include <machine/bus.h>
 
+#include <net/ethernet.h>
 #include <net/if.h>
 #include <net/if_media.h>
 #include <dev/mii/mii.h>
@@ -40,6 +41,7 @@
 #define JH7110_CSR_FREQ		198000000
 
 #define	WR4(sc, o, v) bus_write_4(sc->base.res[EQOS_RES_MEM], (o), (v))
+#define	RD4(sc, o)	bus_read_4(sc->base.res[EQOS_RES_MEM], (o))
 
 static const struct ofw_compat_data compat_data[] = {
 	{"starfive,jh7110-dwmac",	1},
@@ -131,6 +133,8 @@ if_eqos_starfive_init(device_t dev)
 	struct if_eqos_starfive_softc *sc = device_get_softc(dev);
 	hwreset_t rst_ahb, rst_stmmaceth;
 	phandle_t node;
+	uint8_t eaddr[ETHER_ADDR_LEN];
+	uint32_t maclo, machi;
 
 	node = ofw_bus_get_node(dev);
 
@@ -186,6 +190,14 @@ if_eqos_starfive_init(device_t dev)
 		return (ENXIO);
 	}
 
+	if (OF_getprop(node, "local-mac-address", eaddr, sizeof(eaddr)) ==
+	    sizeof(eaddr)) {
+		machi = eaddr[5] | (eaddr[4] << 8);
+		WR4(sc, GMAC_MAC_ADDRESS0_HIGH, machi);
+		maclo = eaddr[3] | (eaddr[2] << 8) | (eaddr[1] << 16) |
+		    (eaddr[0] << 24);
+		WR4(sc, GMAC_MAC_ADDRESS0_LOW, maclo);
+	}
 	return (0);
 }