brcm47xx: do not use mac addresses with 00:90:4C prefix, prevent mac address collisions.

The address prefix 00:90:4C is used by Broadcom in their initial
configuration. When a mac address with the prefix 00:90:4C is used
all devices from the same series are sharing the same mac address.
To prevent mac address collisions we replace them with a mac address
based on the base address.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 41513

1 files changed, 68 insertions, 0 deletions

diff --git a/target/linux/brcm47xx/patches-3.14/180-generate-mac-address.patch b/target/linux/brcm47xx/patches-3.14/180-generate-mac-address.patch
new file mode 100644
index 0000000000..58112ce7f1
--- /dev/null
+++ b/target/linux/brcm47xx/patches-3.14/180-generate-mac-address.patch
@@ -0,0 +1,68 @@
+--- a/arch/mips/bcm47xx/sprom.c
++++ b/arch/mips/bcm47xx/sprom.c
+@@ -28,6 +28,7 @@
+ 
+ #include <bcm47xx.h>
+ #include <bcm47xx_nvram.h>
++#include <linux/if_ether.h>
+ 
+ static void create_key(const char *prefix, const char *postfix,
+ 		       const char *name, char *buf, int len)
+@@ -631,6 +632,33 @@ static void bcm47xx_fill_sprom_path_r45(
+ 	}
+ }
+ 
++static bool bcm47xx_is_valid_mac(u8 *mac)
++{
++	return !(mac[0] == 0x00 && mac[1] == 0x90 && mac[2] == 0x4c);
++}
++
++static int bcm47xx_increase_mac_addr(u8 *mac, u8 num)
++{
++	u8 *oui = mac + ETH_ALEN/2 - 1;
++	u8 *p = mac + ETH_ALEN - 1;
++
++	do {
++		(*p) += num;
++		if (*p > num)
++			break;
++		p--;
++		num = 1;
++	} while (p != oui);
++
++	if (p == oui) {
++		pr_err("unable to fetch mac address\n");
++		return -ENOENT;
++	}
++	return 0;
++}
++
++static int mac_addr_used = 1;
++
+ static void bcm47xx_fill_sprom_ethernet(struct ssb_sprom *sprom,
+ 					const char *prefix, bool fallback)
+ {
+@@ -648,6 +676,23 @@ static void bcm47xx_fill_sprom_ethernet(
+ 
+ 	nvram_read_macaddr(prefix, "macaddr", sprom->il0mac, fallback);
+ 	nvram_read_macaddr(prefix, "il0macaddr", sprom->il0mac, fallback);
++
++	/* The address prefix 00:90:4C is used by Broadcom in their initial
++	   configuration. When a mac address with the prefix 00:90:4C is used
++	   all devices from the same series are sharing the same mac address.
++	   To prevent mac address collisions we replace them with a mac address
++	   based on the base address. */
++	if (!bcm47xx_is_valid_mac(sprom->il0mac)) {
++		u8 mac[6];
++		nvram_read_macaddr(NULL, "et0macaddr", mac, false);
++		if (bcm47xx_is_valid_mac(mac)) {
++			int err = bcm47xx_increase_mac_addr(mac, mac_addr_used);
++			if (!err) {
++				memcpy(sprom->il0mac, mac, ETH_ALEN);
++				mac_addr_used++;
++			}
++		}
++	}
+ }
+ 
+ static void bcm47xx_fill_board_data(struct ssb_sprom *sprom, const char *prefix,