powerpc/85xx: fix null pointer dereference when init the SGMII TBI PHY

Function dtsec_configure_serdes() needs to know where the TBI PHY registers
are in order to configure SGMII for proper SerDes operation.

During SGMII initialzation, fm_eth_init_mac() passing NULL for 'phyregs'
when it called init_dtsec(), because it was believed that phyregs was not
used.  In fact, it is used by dtsec_configure_serdes() to configure the TBI
PHY registers.

We also need to define the PHY registers in struct fm_mdio.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/include/asm/fsl_fman.h

@@ -405,7 +405,14 @@ typedef struct fm_dtesc {
 } fm_dtsec_t;
 
 typedef struct fm_mdio {
-	u8	res[4*1024];
+	u8	res0[0x120];
+	u32	miimcfg;	/* MII management configuration reg */
+	u32	miimcom;	/* MII management command reg */
+	u32	miimadd;	/* MII management address reg */
+	u32	miimcon;	/* MII management control reg */
+	u32	miimstat;	/* MII management status reg  */
+	u32	miimind;	/* MII management indication reg */
+	u8	res1[0x1000 - 0x138];
 } fm_mdio_t;
 
 typedef struct fm_10gec {

drivers/net/fm/dtsec.c

@@ -171,7 +171,7 @@ void init_dtsec(struct fsl_enet_mac *mac, void *base,
 		void *phyregs, int max_rx_len)
 {
 	mac->base = base;
-	mac->phyregs = NULL;
+	mac->phyregs = phyregs;
 	mac->max_rx_len = max_rx_len;
 	mac->init_mac = dtsec_init_mac;
 	mac->enable_mac = dtsec_enable_mac;

drivers/net/fm/eth.c

@@ -537,6 +537,7 @@ static int fm_eth_init_mac(struct fm_eth *fm_eth, struct ccsr_fman *reg)
 	/* Get the mac registers base address */
 	if (fm_eth->type == FM_ETH_1G_E) {
 		base = &reg->mac_1g[num].fm_dtesc;
+		phyregs = &reg->mac_1g[num].fm_mdio.miimcfg;
 	} else {
 		base = &reg->mac_10g[num].fm_10gec;
 		phyregs = &reg->mac_10g[num].fm_10gec_mdio;
@@ -552,7 +553,7 @@ static int fm_eth_init_mac(struct fm_eth *fm_eth, struct ccsr_fman *reg)
 	fm_eth->mac = mac;
 
 	if (fm_eth->type == FM_ETH_1G_E)
-		init_dtsec(mac, base, NULL, MAX_RXBUF_LEN);
+		init_dtsec(mac, base, phyregs, MAX_RXBUF_LEN);
 	else
 		init_tgec(mac, base, phyregs, MAX_RXBUF_LEN);