[RFC PATCH net-next 0/2] Add multicast filtering support for ICSSG driver

[RFC PATCH net-next 0/2] Add multicast filtering support for ICSSG driver

[MD Danish Anwar]

This series add multicast filtering support for ICSSG driver.

The patch 1/2 of the series introduces helper APIs needed to configure
FDB tables maintained by firmware.

Patch 2/2 introduces the support for multicast filtering.

The driver will keep a copy of multicast addresses in emac->mcast_list.
This list will be kept in sync with the netdev list and to add / del
multicast address icssg_prueth_mac_add_mcast / icssg_prueth_mac_del_mcast
APIs will be called.

To add a mac_address for a port, driver need to call icssg_fdb_add_del()
and pass the mac_address and BIT(port_id) to the API. The ICSSG firmware
will then configure the rules and allow filtering.

If a mac_address is added to port0 and the same mac_address needs to be
added for port1, driver needs to pass BIT(port0) | BIT(port1) to the 
icssg_fdb_add_del() API. If driver just pass BIT(port1) then the entry for
port0 will be overwritten / lost. This is a design constraint on the
firmware side.

To overcome this in the driver, to add any mac_address for let's say portX
driver first checks if the same mac_address is already added for any other
port. If yes driver calls icssg_fdb_add_del() with BIT(portX) | 
BIT(other_existing_port). If not, driver calls icssg_fdb_add_del() with 
BIT(portX).

The same thing is applicable for deleting mac_addresses as well. This
logic is in icssg_prueth_mac_add_mcast / icssg_prueth_mac_del_mcast APIs.

MD Danish Anwar (2):
  net: ti: icssg-prueth: Add helper functions to configure FDB
  net: ti: icssg-prueth: Add multicast filtering support

 drivers/net/ethernet/ti/icssg/icssg_config.c | 186 ++++++++++++++++++-
 drivers/net/ethernet/ti/icssg/icssg_config.h |  19 ++
 drivers/net/ethernet/ti/icssg/icssg_prueth.c |  50 ++++-
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |  15 ++
 4 files changed, 263 insertions(+), 7 deletions(-)


base-commit: 654de42f3fc6edc29d743c1dbcd1424f7793f63d
-- 
2.34.1

[RFC PATCH net-next 1/2] net: ti: icssg-prueth: Add helper functions to configure FDB

[MD Danish Anwar]

Introduce helper functions to configure firmware FDB tables, VLAN tables
and Port VLAN ID settings.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/ti/icssg/icssg_config.c | 170 +++++++++++++++++++
 drivers/net/ethernet/ti/icssg/icssg_config.h |  19 +++
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |  12 ++
 3 files changed, 201 insertions(+)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.c b/drivers/net/ethernet/ti/icssg/icssg_config.c
index 15f2235bf90f..2213374d4d45 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_config.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_config.c
@@ -477,3 +477,173 @@ void icssg_config_set_speed(struct prueth_emac *emac)
 
 	writeb(fw_speed, emac->dram.va + PORT_LINK_SPEED_OFFSET);
 }
+
+int icssg_send_fdb_msg(struct prueth_emac *emac, struct mgmt_cmd *cmd,
+		       struct mgmt_cmd_rsp *rsp)
+{
+	struct prueth *prueth = emac->prueth;
+	int slice = prueth_emac_slice(emac);
+	int addr, ret;
+
+	addr = icssg_queue_pop(prueth, slice == 0 ?
+			       ICSSG_CMD_POP_SLICE0 : ICSSG_CMD_POP_SLICE1);
+	if (addr < 0)
+		return addr;
+
+	/* First 4 bytes have FW owned buffer linking info which should
+	 * not be touched
+	 */
+	memcpy_toio(prueth->shram.va + addr + 4, cmd, sizeof(*cmd));
+	icssg_queue_push(prueth, slice == 0 ?
+			 ICSSG_CMD_PUSH_SLICE0 : ICSSG_CMD_PUSH_SLICE1, addr);
+	ret = read_poll_timeout(icssg_queue_pop, addr, addr >= 0,
+				2000, 20000000, false, prueth, slice == 0 ?
+				ICSSG_RSP_POP_SLICE0 : ICSSG_RSP_POP_SLICE1);
+	if (ret) {
+		netdev_err(emac->ndev, "Timedout sending HWQ message\n");
+		return ret;
+	}
+
+	memcpy_fromio(rsp, prueth->shram.va + addr, sizeof(*rsp));
+	/* Return buffer back for to pool */
+	icssg_queue_push(prueth, slice == 0 ?
+			 ICSSG_RSP_PUSH_SLICE0 : ICSSG_RSP_PUSH_SLICE1, addr);
+
+	return 0;
+}
+
+static void icssg_fdb_setup(struct prueth_emac *emac, struct mgmt_cmd *fdb_cmd,
+			    const unsigned char *addr, u8 fid, int cmd)
+{
+	int slice = prueth_emac_slice(emac);
+	u8 mac_fid[ETH_ALEN + 2];
+	u16 fdb_slot;
+
+	ether_addr_copy(mac_fid, addr);
+
+	/* 1-1 VID-FID mapping is already setup */
+	mac_fid[ETH_ALEN] = fid;
+	mac_fid[ETH_ALEN + 1] = 0;
+
+	fdb_slot = bitrev32(crc32_le(0, mac_fid, 8)) & PRUETH_SWITCH_FDB_MASK;
+
+	fdb_cmd->header = ICSSG_FW_MGMT_CMD_HEADER;
+	fdb_cmd->type   = ICSSG_FW_MGMT_FDB_CMD_TYPE;
+	fdb_cmd->seqnum = ++(emac->prueth->icssg_hwcmdseq);
+	fdb_cmd->param  = cmd;
+	fdb_cmd->param |= (slice << 4);
+
+	memcpy(&fdb_cmd->cmd_args[0], addr, 4);
+	memcpy(&fdb_cmd->cmd_args[1], &addr[4], 2);
+	fdb_cmd->cmd_args[2] = fdb_slot;
+
+	netdev_dbg(emac->ndev, "MAC %pM slot %X FID %X\n", addr, fdb_slot, fid);
+}
+
+int icssg_fdb_add_del(struct prueth_emac *emac, const unsigned char *addr,
+		      u8 vid, u8 fid_c2, bool add)
+{
+	struct mgmt_cmd_rsp fdb_cmd_rsp = { 0 };
+	struct mgmt_cmd fdb_cmd = { 0 };
+	u8 fid = vid;
+	int ret;
+
+	icssg_fdb_setup(emac, &fdb_cmd, addr, fid, add ? ICSS_CMD_ADD_FDB : ICSS_CMD_DEL_FDB);
+
+	fid_c2 |= ICSSG_FDB_ENTRY_VALID;
+	fdb_cmd.cmd_args[1] |= ((fid << 16) | (fid_c2 << 24));
+
+	ret = icssg_send_fdb_msg(emac, &fdb_cmd, &fdb_cmd_rsp);
+	if (ret)
+		return ret;
+
+	WARN_ON(fdb_cmd.seqnum != fdb_cmd_rsp.seqnum);
+	if (fdb_cmd_rsp.status == 1)
+		return 0;
+
+	return -EINVAL;
+}
+
+int icssg_fdb_lookup(struct prueth_emac *emac, const unsigned char *addr,
+		     u8 vid)
+{
+	struct mgmt_cmd_rsp fdb_cmd_rsp = { 0 };
+	struct mgmt_cmd fdb_cmd = { 0 };
+	struct prueth_fdb_slot *slot;
+	u8 fid = vid;
+	int ret, i;
+
+	icssg_fdb_setup(emac, &fdb_cmd, addr, fid, ICSS_CMD_GET_FDB_SLOT);
+
+	fdb_cmd.cmd_args[1] |= fid << 16;
+
+	ret = icssg_send_fdb_msg(emac, &fdb_cmd, &fdb_cmd_rsp);
+	if (ret)
+		return ret;
+
+	WARN_ON(fdb_cmd.seqnum != fdb_cmd_rsp.seqnum);
+
+	slot = (struct prueth_fdb_slot __force *)(emac->dram.va + FDB_CMD_BUFFER);
+	for (i = 0; i < 4; i++) {
+		if (ether_addr_equal(addr, slot->mac) && vid == slot->fid)
+			return (slot->fid_c2 & ~ICSSG_FDB_ENTRY_VALID);
+		slot++;
+	}
+
+	return 0;
+}
+
+void icssg_vtbl_modify(struct prueth_emac *emac, u8 vid, u8 port_mask,
+		       u8 untag_mask, bool add)
+{
+	struct prueth *prueth = emac->prueth;
+	struct prueth_vlan_tbl *tbl;
+	u8 fid_c1;
+
+	tbl = prueth->vlan_tbl;
+	fid_c1 = tbl[vid].fid_c1;
+
+	/* FID_C1: bit0..2 port membership mask,
+	 * bit3..5 tagging mask for each port
+	 * bit6 Stream VID (not handled currently)
+	 * bit7 MC flood (not handled currently)
+	 */
+	if (add) {
+		fid_c1 |= (port_mask | port_mask << 3);
+		fid_c1 &= ~(untag_mask << 3);
+	} else {
+		fid_c1 &= ~(port_mask | port_mask << 3);
+	}
+
+	tbl[vid].fid_c1 = fid_c1;
+}
+
+u16 icssg_get_pvid(struct prueth_emac *emac)
+{
+	struct prueth *prueth = emac->prueth;
+	u32 pvid;
+
+	if (emac->port_id == PRUETH_PORT_MII0)
+		pvid = readl(prueth->shram.va + EMAC_ICSSG_SWITCH_PORT1_DEFAULT_VLAN_OFFSET);
+	else
+		pvid = readl(prueth->shram.va + EMAC_ICSSG_SWITCH_PORT2_DEFAULT_VLAN_OFFSET);
+
+	pvid = pvid >> 24;
+
+	return pvid;
+}
+
+void icssg_set_pvid(struct prueth *prueth, u8 vid, u8 port)
+{
+	u32 pvid;
+
+	/* only 256 VLANs are supported */
+	pvid = (u32 __force)cpu_to_be32((ETH_P_8021Q << 16) | (vid & 0xff));
+
+	if (port == PRUETH_PORT_MII0)
+		writel(pvid, prueth->shram.va + EMAC_ICSSG_SWITCH_PORT1_DEFAULT_VLAN_OFFSET);
+	else if (port == PRUETH_PORT_MII1)
+		writel(pvid, prueth->shram.va + EMAC_ICSSG_SWITCH_PORT2_DEFAULT_VLAN_OFFSET);
+	else
+		writel(pvid, prueth->shram.va + EMAC_ICSSG_SWITCH_PORT0_DEFAULT_VLAN_OFFSET);
+}
diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.h b/drivers/net/ethernet/ti/icssg/icssg_config.h
index cf2ea4bd22a2..9d8558bd0f15 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_config.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_config.h
@@ -35,6 +35,8 @@ struct icssg_flow_cfg {
 	(2 * (PRUETH_EMAC_BUF_POOL_SIZE * PRUETH_NUM_BUF_POOLS + \
 	 PRUETH_EMAC_RX_CTX_BUF_SIZE * 2))
 
+#define PRUETH_SWITCH_FDB_MASK ((SIZE_OF_FDB / NUMBER_OF_FDB_BUCKET_ENTRIES) - 1)
+
 struct icssg_rxq_ctx {
 	__le32 start[3];
 	__le32 end;
@@ -202,6 +204,23 @@ struct icssg_setclock_desc {
 #define ICSSG_TS_PUSH_SLICE0	40
 #define ICSSG_TS_PUSH_SLICE1	41
 
+struct mgmt_cmd {
+	u8 param;
+	u8 seqnum;
+	u8 type;
+	u8 header;
+	u32 cmd_args[3];
+} __packed;
+
+struct mgmt_cmd_rsp {
+	u32 reserved;
+	u8 status;
+	u8 seqnum;
+	u8 type;
+	u8 header;
+	u32 cmd_args[3];
+} __packed;
+
 /* FDB FID_C2 flag definitions */
 /* Indicates host port membership.*/
 #define ICSSG_FDB_ENTRY_P0_MEMBERSHIP         BIT(0)
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index a78c5eb75fb8..82bdad9702c3 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -232,6 +232,7 @@ struct icssg_firmwares {
  * @emacs_initialized: num of EMACs/ext ports that are up/running
  * @iep0: pointer to IEP0 device
  * @iep1: pointer to IEP1 device
+ * @vlan_tbl: VLAN-FID table pointer
  */
 struct prueth {
 	struct device *dev;
@@ -256,6 +257,7 @@ struct prueth {
 	int emacs_initialized;
 	struct icss_iep *iep0;
 	struct icss_iep *iep1;
+	struct prueth_vlan_tbl *vlan_tbl;
 };
 
 struct emac_tx_ts_response {
@@ -313,6 +315,16 @@ int icssg_queue_pop(struct prueth *prueth, u8 queue);
 void icssg_queue_push(struct prueth *prueth, int queue, u16 addr);
 u32 icssg_queue_level(struct prueth *prueth, int queue);
 
+int icssg_send_fdb_msg(struct prueth_emac *emac, struct mgmt_cmd *cmd,
+		       struct mgmt_cmd_rsp *rsp);
+int icssg_fdb_add_del(struct prueth_emac *emac,  const unsigned char *addr,
+		      u8 vid, u8 fid_c2, bool add);
+int icssg_fdb_lookup(struct prueth_emac *emac, const unsigned char *addr,
+		     u8 vid);
+void icssg_vtbl_modify(struct prueth_emac *emac, u8 vid, u8 port_mask,
+		       u8 untag_mask, bool add);
+u16 icssg_get_pvid(struct prueth_emac *emac);
+void icssg_set_pvid(struct prueth *prueth, u8 vid, u8 port);
 #define prueth_napi_to_tx_chn(pnapi) \
 	container_of(pnapi, struct prueth_tx_chn, napi_tx)
 
-- 
2.34.1

[RFC PATCH net-next 2/2] net: ti: icssg-prueth: Add multicast filtering support

[MD Danish Anwar]

Add multicast filtering support for ICSSG Driver.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
---
 drivers/net/ethernet/ti/icssg/icssg_config.c | 16 +++++--
 drivers/net/ethernet/ti/icssg/icssg_prueth.c | 50 ++++++++++++++++++--
 drivers/net/ethernet/ti/icssg/icssg_prueth.h |  3 ++
 3 files changed, 62 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.c b/drivers/net/ethernet/ti/icssg/icssg_config.c
index 2213374d4d45..4e30bb995078 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_config.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_config.c
@@ -318,17 +318,27 @@ static int prueth_emac_buffer_setup(struct prueth_emac *emac)
 
 static void icssg_init_emac_mode(struct prueth *prueth)
 {
+	u32 addr = prueth->shram.pa + VLAN_STATIC_REG_TABLE_OFFSET;
 	/* When the device is configured as a bridge and it is being brought
 	 * back to the emac mode, the host mac address has to be set as 0.
 	 */
 	u8 mac[ETH_ALEN] = { 0 };
+	int i;
 
 	if (prueth->emacs_initialized)
 		return;
 
-	regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1,
-			   SMEM_VLAN_OFFSET_MASK, 0);
-	regmap_write(prueth->miig_rt, FDB_GEN_CFG2, 0);
+	/* Set VLAN TABLE address base */
+	regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1, SMEM_VLAN_OFFSET_MASK,
+			   addr <<  SMEM_VLAN_OFFSET);
+	/* Configure CFG2 register */
+	regmap_write(prueth->miig_rt, FDB_GEN_CFG2, (FDB_PRU0_EN | FDB_PRU1_EN | FDB_HOST_EN));
+
+	prueth->vlan_tbl = prueth->shram.va + VLAN_STATIC_REG_TABLE_OFFSET;
+	for (i = 0; i < SZ_4K - 1; i++) {
+		prueth->vlan_tbl[i].fid = i;
+		prueth->vlan_tbl[i].fid_c1 = 0;
+	}
 	/* Clear host MAC address */
 	icssg_class_set_host_mac_addr(prueth->miig_rt, mac);
 }
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
index 7c9e9518f555..bd343c4b6b57 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
@@ -417,6 +417,37 @@ const struct icss_iep_clockops prueth_iep_clockops = {
 	.perout_enable = prueth_perout_enable,
 };
 
+static int icssg_prueth_mac_add_mcast(struct net_device *ndev, const u8 *addr)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	int port_mask = BIT(emac->port_id);
+
+	port_mask |= icssg_fdb_lookup(emac, addr, 0);
+	icssg_fdb_add_del(emac, addr, 0, port_mask, true);
+	icssg_vtbl_modify(emac, 0, port_mask, port_mask, true);
+
+	return 0;
+}
+
+static int icssg_prueth_mac_del_mcast(struct net_device *ndev, const u8 *addr)
+{
+	struct prueth_emac *emac = netdev_priv(ndev);
+	int port_mask = BIT(emac->port_id);
+	int other_port_mask;
+
+	other_port_mask = port_mask ^ icssg_fdb_lookup(emac, addr, 0);
+
+	icssg_fdb_add_del(emac, addr, 0, port_mask, false);
+	icssg_vtbl_modify(emac, 0, port_mask, port_mask, false);
+
+	if (other_port_mask) {
+		icssg_fdb_add_del(emac, addr, 0, other_port_mask, true);
+		icssg_vtbl_modify(emac, 0, other_port_mask, other_port_mask, true);
+	}
+
+	return 0;
+}
+
 /**
  * emac_ndo_open - EMAC device open
  * @ndev: network adapter device
@@ -526,6 +557,8 @@ static int emac_ndo_open(struct net_device *ndev)
 
 	prueth->emacs_initialized++;
 
+	__hw_addr_init(&emac->mcast_list);
+
 	queue_work(system_long_wq, &emac->stats_work.work);
 
 	return 0;
@@ -578,6 +611,9 @@ static int emac_ndo_stop(struct net_device *ndev)
 
 	icssg_class_disable(prueth->miig_rt, prueth_emac_slice(emac));
 
+	__dev_mc_unsync(ndev, icssg_prueth_mac_del_mcast);
+	__hw_addr_init(&emac->mcast_list);
+
 	atomic_set(&emac->tdown_cnt, emac->tx_ch_num);
 	/* ensure new tdown_cnt value is visible */
 	smp_mb__after_atomic();
@@ -654,10 +690,15 @@ static void emac_ndo_set_rx_mode_work(struct work_struct *work)
 		return;
 	}
 
-	if (!netdev_mc_empty(ndev)) {
-		emac_set_port_state(emac, ICSSG_EMAC_PORT_MC_FLOODING_ENABLE);
-		return;
-	}
+	/* make a mc list copy */
+
+	netif_addr_lock_bh(ndev);
+	__hw_addr_sync(&emac->mcast_list, &ndev->mc, ndev->addr_len);
+	netif_addr_unlock_bh(ndev);
+
+	__hw_addr_sync_dev(&emac->mcast_list, ndev,
+			   icssg_prueth_mac_add_mcast,
+			   icssg_prueth_mac_del_mcast);
 }
 
 /**
@@ -746,6 +787,7 @@ static int prueth_netdev_init(struct prueth *prueth,
 	SET_NETDEV_DEV(ndev, prueth->dev);
 	spin_lock_init(&emac->lock);
 	mutex_init(&emac->cmd_lock);
+	__hw_addr_init(&emac->mcast_list);
 
 	emac->phy_node = of_parse_phandle(eth_node, "phy-handle", 0);
 	if (!emac->phy_node && !of_phy_is_fixed_link(eth_node)) {
diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.h b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
index 82bdad9702c3..0cad80a437e8 100644
--- a/drivers/net/ethernet/ti/icssg/icssg_prueth.h
+++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.h
@@ -155,6 +155,9 @@ struct prueth_emac {
 	unsigned int tx_ts_enabled : 1;
 	unsigned int half_duplex : 1;
 
+	/* List for storing mutlicast addresses */
+	struct netdev_hw_addr_list mcast_list;
+
 	/* DMA related */
 	struct prueth_tx_chn tx_chns[PRUETH_MAX_TX_QUEUES];
 	struct completion tdown_complete;
-- 
2.34.1

Re: [RFC PATCH net-next 2/2] net: ti: icssg-prueth: Add multicast filtering support

[Simon Horman]

On Thu, May 16, 2024 at 02:47:52PM +0530, MD Danish Anwar wrote:
> Add multicast filtering support for ICSSG Driver.
> 
> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
> ---
>  drivers/net/ethernet/ti/icssg/icssg_config.c | 16 +++++--
>  drivers/net/ethernet/ti/icssg/icssg_prueth.c | 50 ++++++++++++++++++--
>  drivers/net/ethernet/ti/icssg/icssg_prueth.h |  3 ++
>  3 files changed, 62 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.c b/drivers/net/ethernet/ti/icssg/icssg_config.c
> index 2213374d4d45..4e30bb995078 100644
> --- a/drivers/net/ethernet/ti/icssg/icssg_config.c
> +++ b/drivers/net/ethernet/ti/icssg/icssg_config.c
> @@ -318,17 +318,27 @@ static int prueth_emac_buffer_setup(struct prueth_emac *emac)
>  
>  static void icssg_init_emac_mode(struct prueth *prueth)
>  {
> +	u32 addr = prueth->shram.pa + VLAN_STATIC_REG_TABLE_OFFSET;
>  	/* When the device is configured as a bridge and it is being brought
>  	 * back to the emac mode, the host mac address has to be set as 0.
>  	 */
>  	u8 mac[ETH_ALEN] = { 0 };
> +	int i;
>  
>  	if (prueth->emacs_initialized)
>  		return;
>  
> -	regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1,
> -			   SMEM_VLAN_OFFSET_MASK, 0);
> -	regmap_write(prueth->miig_rt, FDB_GEN_CFG2, 0);
> +	/* Set VLAN TABLE address base */
> +	regmap_update_bits(prueth->miig_rt, FDB_GEN_CFG1, SMEM_VLAN_OFFSET_MASK,
> +			   addr <<  SMEM_VLAN_OFFSET);
> +	/* Configure CFG2 register */
> +	regmap_write(prueth->miig_rt, FDB_GEN_CFG2, (FDB_PRU0_EN | FDB_PRU1_EN | FDB_HOST_EN));
> +
> +	prueth->vlan_tbl = prueth->shram.va + VLAN_STATIC_REG_TABLE_OFFSET;
> +	for (i = 0; i < SZ_4K - 1; i++) {
> +		prueth->vlan_tbl[i].fid = i;
> +		prueth->vlan_tbl[i].fid_c1 = 0;
> +	}

Hi MD,

This isnot a full review, but I did notice one thing.

According to Sparse, prueth->shram.va is __iomem.
I don't think it is portable to directly access __iomem like this.
Rather, I suspect that either ioremap(), or writel() or similar should be used.

>  	/* Clear host MAC address */
>  	icssg_class_set_host_mac_addr(prueth->miig_rt, mac);
>  }

...