net/macb: unify peripheral version testing

As we need to check peripheral version from the hardware during probe, I
introduce a little helper to unify these tests. It would prevent to
de-synchronize the test like previously observed.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.c

@@ -2139,10 +2139,9 @@ static void macb_configure_caps(struct macb *bp, const struct macb_config *dt_co
 	if (dt_conf)
 		bp->caps = dt_conf->caps;
 
-	if (MACB_BFEXT(IDNUM, macb_readl(bp, MID)) >= 0x2)
+	if (macb_is_gem_hw(bp->regs)) {
 		bp->caps |= MACB_CAPS_MACB_IS_GEM;
 
-	if (macb_is_gem(bp)) {
 		dcfg = gem_readl(bp, DCFG1);
 		if (GEM_BFEXT(IRQCOR, dcfg) == 0)
 			bp->caps |= MACB_CAPS_ISR_CLEAR_ON_WRITE;
@@ -2159,7 +2158,6 @@ static void macb_probe_queues(void __iomem *mem,
 			      unsigned int *num_queues)
 {
 	unsigned int hw_q;
-	u32 mid;
 
 	*queue_mask = 0x1;
 	*num_queues = 1;
@@ -2170,8 +2168,7 @@ static void macb_probe_queues(void __iomem *mem,
 	 * we are early in the probe process and don't have the
 	 * MACB_CAPS_MACB_IS_GEM flag positioned
 	 */
-	mid = readl_relaxed(mem + MACB_MID);
-	if (MACB_BFEXT(IDNUM, mid) < 0x2)
+	if (!macb_is_gem_hw(mem))
 		return;
 
 	/* bit 0 is never set but queue 0 always exists */

drivers/net/ethernet/cadence/macb.h

@@ -833,4 +833,9 @@ static inline bool macb_is_gem(struct macb *bp)
 	return !!(bp->caps & MACB_CAPS_MACB_IS_GEM);
 }
 
+static inline bool macb_is_gem_hw(void __iomem *addr)
+{
+	return !!(MACB_BFEXT(IDNUM, readl_relaxed(addr + MACB_MID)) >= 0x2);
+}
+
 #endif /* _MACB_H */