net: atlantic: unify MAC generation

This patch unifies invalid MAC address handling with other drivers.

Basically we've switched to using standard APIs (is_valid_ether_addr /
eth_hw_addr_random) where possible.
It's worth noting that some of engineering Aquantia NICs might be
provisioned with a partially zeroed out MAC, which is still invalid,
but not caught by is_valid_ether_addr(), so we've added a special
handling for this case.

Also adding a warning in case of fallback to random MAC, because
this shouldn't be needed on production NICs, they should all be
provisioned with unique MAC.

NB! Default systemd/udevd configuration is 'MACAddressPolicy=persistent'.
    This causes MAC address to be persisted across driver reloads and
    reboots. We had to change it to 'none' for verification purposes.
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/aquantia/atlantic/aq_nic.c

@@ -272,6 +272,14 @@ static int aq_nic_hw_prepare(struct aq_nic_s *self)
 	return err;
 }
 
+static bool aq_nic_is_valid_ether_addr(const u8 *addr)
+{
+	/* Some engineering samples of Aquantia NICs are provisioned with a
+	 * partially populated MAC, which is still invalid.
+	 */
+	return !(addr[0] == 0 && addr[1] == 0 && addr[2] == 0);
+}
+
 int aq_nic_ndev_register(struct aq_nic_s *self)
 {
 	int err = 0;
@@ -296,6 +304,12 @@ int aq_nic_ndev_register(struct aq_nic_s *self)
 	if (err)
 		goto err_exit;
 
+	if (!is_valid_ether_addr(self->ndev->dev_addr) ||
+	    !aq_nic_is_valid_ether_addr(self->ndev->dev_addr)) {
+		netdev_warn(self->ndev, "MAC is invalid, will use random.");
+		eth_hw_addr_random(self->ndev);
+	}
+
 #if defined(AQ_CFG_MAC_ADDR_PERMANENT)
 	{
 		static u8 mac_addr_permanent[] = AQ_CFG_MAC_ADDR_PERMANENT;

drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils_fw2x.c

@@ -283,8 +283,6 @@ static int aq_fw2x_get_mac_permanent(struct aq_hw_s *self, u8 *mac)
 	u32 efuse_addr = aq_hw_read_reg(self, HW_ATL_FW2X_MPI_EFUSE_ADDR);
 	u32 mac_addr[2] = { 0 };
 	int err = 0;
-	u32 h = 0U;
-	u32 l = 0U;
 
 	if (efuse_addr != 0) {
 		err = hw_atl_utils_fw_downld_dwords(self,
@@ -299,26 +297,6 @@ static int aq_fw2x_get_mac_permanent(struct aq_hw_s *self, u8 *mac)
 
 	ether_addr_copy(mac, (u8 *)mac_addr);
 
-	if ((mac[0] & 0x01U) || ((mac[0] | mac[1] | mac[2]) == 0x00U)) {
-		unsigned int rnd = 0;
-
-		get_random_bytes(&rnd, sizeof(unsigned int));
-
-		l = 0xE3000000U | (0xFFFFU & rnd) | (0x00 << 16);
-		h = 0x8001300EU;
-
-		mac[5] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[4] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[3] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[2] = (u8)(0xFFU & l);
-		mac[1] = (u8)(0xFFU & h);
-		h >>= 8;
-		mac[0] = (u8)(0xFFU & h);
-	}
-
 	return err;
 }
 

drivers/net/ethernet/aquantia/atlantic/hw_atl2/hw_atl2_utils_fw.c

@@ -6,6 +6,7 @@
 #include <linux/iopoll.h>
 
 #include "aq_hw.h"
+#include "aq_hw_utils.h"
 #include "hw_atl/hw_atl_llh.h"
 #include "hw_atl2_utils.h"
 #include "hw_atl2_llh.h"
@@ -212,28 +213,6 @@ static int aq_a2_fw_get_mac_permanent(struct aq_hw_s *self, u8 *mac)
 	hw_atl2_shared_buffer_get(self, mac_address, mac_address);
 	ether_addr_copy(mac, (u8 *)mac_address.aligned.mac_address);
 
-	if ((mac[0] & 0x01U) || ((mac[0] | mac[1] | mac[2]) == 0x00U)) {
-		unsigned int rnd = 0;
-		u32 h;
-		u32 l;
-
-		get_random_bytes(&rnd, sizeof(unsigned int));
-
-		l = 0xE3000000U | (0xFFFFU & rnd) | (0x00 << 16);
-		h = 0x8001300EU;
-
-		mac[5] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[4] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[3] = (u8)(0xFFU & l);
-		l >>= 8;
-		mac[2] = (u8)(0xFFU & l);
-		mac[1] = (u8)(0xFFU & h);
-		h >>= 8;
-		mac[0] = (u8)(0xFFU & h);
-	}
-
 	return 0;
 }