of_net: factor out repetitive code from of_get_mac_address()

of_get_mac_address() basically does the same thing thrice, every time with a different property name, so it makes sense to factor out the repetitive code into separate function. While at it, we can start using ETH_ALEN instead of the bare number and drop unnecessary parens around the property length check.

The resulting ARM object file is 100 bytes less in size than before the patch.

Signed-off-by Sergei Shtylyov <[email protected]>

---
The patch is against Grant Likely's 'linux.git' repo's 'devicetree/next' branch.

of_get_mac_address() basically does the same thing thrice, every time with a different property name, so it makes sense to factor out the repetitive code into separate function. While at it, we can start using ETH_ALEN instead of the bare number and drop unnecessary parens around the property length check.

The resulting ARM object file is 100 bytes less in size than before the patch.

Signed-off-by Sergei Shtylyov <sergei.shtylyov-M4DtvfQ/[email protected]>

---
The patch is against Grant Likely's 'linux.git' repo's 'devicetree/next' branch.

 drivers/of/of_net.c |   29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

Index: linux/drivers/of/of_net.c
===================================================================

drivers/of/of_net.c +17 -12

@@ -38,6 +38,15 @@ int of_get_phy_mode(struct device_node *
 }
 EXPORT_SYMBOL_GPL(of_get_phy_mode);
 
+static const void *of_get_mac_addr(struct device_node *np, const char *name)
+{
+	struct property *pp = of_find_property(np, name, NULL);
+
+	if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
+		return pp->value;
+	return NULL;
+}
+
 /**
  * Search the device tree for the best MAC address to use.  'mac-address' is
  * checked first, because that is supposed to contain to "most recent" MAC

@@ -58,20 +67,16 @@ EXPORT_SYMBOL_GPL(of_get_phy_mode);
 */
 const void *of_get_mac_address(struct device_node *np)
 {
-	struct property *pp;
+	const void *addr;
 
-	pp = of_find_property(np, "mac-address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
+	addr = of_get_mac_addr(np, "mac-address");
+	if (addr)
+		return addr;
 
-	pp = of_find_property(np, "local-mac-address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
+	addr = of_get_mac_addr(np, "local-mac-address");
+	if (addr)
+		return addr;
 
-	pp = of_find_property(np, "address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
-
-	return NULL;
+	return of_get_mac_addr(np, "address");
 }
 EXPORT_SYMBOL(of_get_mac_address);

From: Sergei Shtylyov <[email protected]>
Date: Wed, 18 Mar 2015 22:25:46 +0300

Quoted 5 lines

of_get_mac_address() basically does the same thing thrice, every time with a different property name, so it makes sense to factor out the repetitive code into separate function. While at it, we can start using ETH_ALEN instead of the bare number and drop unnecessary parens around the property length check.

Quoted 6 lines

The resulting ARM object file is 100 bytes less in size than before the patch.

Signed-off-by Sergei Shtylyov <[email protected]>

---
The patch is against Grant Likely's 'linux.git' repo's 'devicetree/next' branch.

Acked-by David S. Miller <[email protected]>

of_get_mac_address() basically does the same thing thrice, every time with a different property name, so it makes sense to factor out the repetitive code into separate function. While at it, we can start using ETH_ALEN instead of the bare number and drop unnecessary parens around the property length check.

The resulting ARM object file is 100 bytes less in size than before the patch.

Signed-off-by Sergei Shtylyov <[email protected]>

---
The patch is against Grant Likely's 'linux.git' repo's 'devicetree/next' branch.

 drivers/of/of_net.c |   29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

Index: linux/drivers/of/of_net.c
===================================================================

drivers/of/of_net.c +17 -12

@@ -38,6 +38,15 @@ int of_get_phy_mode(struct device_node *
 }
 EXPORT_SYMBOL_GPL(of_get_phy_mode);
 
+static const void *of_get_mac_addr(struct device_node *np, const char *name)
+{
+	struct property *pp = of_find_property(np, name, NULL);
+
+	if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
+		return pp->value;
+	return NULL;
+}
+
 /**
  * Search the device tree for the best MAC address to use.  'mac-address' is
  * checked first, because that is supposed to contain to "most recent" MAC

@@ -58,20 +67,16 @@ EXPORT_SYMBOL_GPL(of_get_phy_mode);
 */
 const void *of_get_mac_address(struct device_node *np)
 {
-	struct property *pp;
+	const void *addr;
 
-	pp = of_find_property(np, "mac-address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
+	addr = of_get_mac_addr(np, "mac-address");
+	if (addr)
+		return addr;
 
-	pp = of_find_property(np, "local-mac-address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
+	addr = of_get_mac_addr(np, "local-mac-address");
+	if (addr)
+		return addr;
 
-	pp = of_find_property(np, "address", NULL);
-	if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
-		return pp->value;
-
-	return NULL;
+	return of_get_mac_addr(np, "address");
 }
 EXPORT_SYMBOL(of_get_mac_address);

Quoted 8 lines

of_get_mac_address() basically does the same thing thrice, every time with a different property name, so it makes sense to factor out the repetitive code into separate function. While at it, we can start using ETH_ALEN instead of the bare number and drop unnecessary parens around the property length check.

The resulting ARM object file is 100 bytes less in size than before the patch.

Signed-off-by Sergei Shtylyov <[email protected]>

Quoted 2 lines

---
The patch is against Grant Likely's 'linux.git' repo's 'devicetree/next' branch.

Thanks for looking at this, I've merged it.

Since you're already playing with this, could you also write a unittest of of_get_mac_addr()? (drivers/of/unittest.c & drivers/of/unittest-data)

g.