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path: root/drivers/net/ethernet/ibm/ibmvnic.c
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Diffstat (limited to 'drivers/net/ethernet/ibm/ibmvnic.c')
-rw-r--r--drivers/net/ethernet/ibm/ibmvnic.c235
1 files changed, 181 insertions, 54 deletions
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 1dc4aef37d3a..1b3cc8bb0705 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -59,6 +59,7 @@
#include <linux/mm.h>
#include <linux/ethtool.h>
#include <linux/proc_fs.h>
+#include <linux/if_arp.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
@@ -353,6 +354,8 @@ static void release_stats_buffers(struct ibmvnic_adapter *adapter)
{
kfree(adapter->tx_stats_buffers);
kfree(adapter->rx_stats_buffers);
+ adapter->tx_stats_buffers = NULL;
+ adapter->rx_stats_buffers = NULL;
}
static int init_stats_buffers(struct ibmvnic_adapter *adapter)
@@ -410,6 +413,10 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
struct ibmvnic_rx_pool *rx_pool;
int rx_scrqs;
int i, j, rc;
+ u64 *size_array;
+
+ size_array = (u64 *)((u8 *)(adapter->login_rsp_buf) +
+ be32_to_cpu(adapter->login_rsp_buf->off_rxadd_buff_size));
rx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_rxadd_subcrqs);
for (i = 0; i < rx_scrqs; i++) {
@@ -417,7 +424,17 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
netdev_dbg(adapter->netdev, "Re-setting rx_pool[%d]\n", i);
- rc = reset_long_term_buff(adapter, &rx_pool->long_term_buff);
+ if (rx_pool->buff_size != be64_to_cpu(size_array[i])) {
+ free_long_term_buff(adapter, &rx_pool->long_term_buff);
+ rx_pool->buff_size = be64_to_cpu(size_array[i]);
+ alloc_long_term_buff(adapter, &rx_pool->long_term_buff,
+ rx_pool->size *
+ rx_pool->buff_size);
+ } else {
+ rc = reset_long_term_buff(adapter,
+ &rx_pool->long_term_buff);
+ }
+
if (rc)
return rc;
@@ -439,14 +456,12 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
static void release_rx_pools(struct ibmvnic_adapter *adapter)
{
struct ibmvnic_rx_pool *rx_pool;
- int rx_scrqs;
int i, j;
if (!adapter->rx_pool)
return;
- rx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_rxadd_subcrqs);
- for (i = 0; i < rx_scrqs; i++) {
+ for (i = 0; i < adapter->num_active_rx_pools; i++) {
rx_pool = &adapter->rx_pool[i];
netdev_dbg(adapter->netdev, "Releasing rx_pool[%d]\n", i);
@@ -469,6 +484,7 @@ static void release_rx_pools(struct ibmvnic_adapter *adapter)
kfree(adapter->rx_pool);
adapter->rx_pool = NULL;
+ adapter->num_active_rx_pools = 0;
}
static int init_rx_pools(struct net_device *netdev)
@@ -493,6 +509,8 @@ static int init_rx_pools(struct net_device *netdev)
return -1;
}
+ adapter->num_active_rx_pools = 0;
+
for (i = 0; i < rxadd_subcrqs; i++) {
rx_pool = &adapter->rx_pool[i];
@@ -536,6 +554,8 @@ static int init_rx_pools(struct net_device *netdev)
rx_pool->next_free = 0;
}
+ adapter->num_active_rx_pools = rxadd_subcrqs;
+
return 0;
}
@@ -581,18 +601,19 @@ static void release_vpd_data(struct ibmvnic_adapter *adapter)
kfree(adapter->vpd->buff);
kfree(adapter->vpd);
+
+ adapter->vpd = NULL;
}
static void release_tx_pools(struct ibmvnic_adapter *adapter)
{
struct ibmvnic_tx_pool *tx_pool;
- int i, tx_scrqs;
+ int i;
if (!adapter->tx_pool)
return;
- tx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_txsubm_subcrqs);
- for (i = 0; i < tx_scrqs; i++) {
+ for (i = 0; i < adapter->num_active_tx_pools; i++) {
netdev_dbg(adapter->netdev, "Releasing tx_pool[%d]\n", i);
tx_pool = &adapter->tx_pool[i];
kfree(tx_pool->tx_buff);
@@ -603,6 +624,7 @@ static void release_tx_pools(struct ibmvnic_adapter *adapter)
kfree(adapter->tx_pool);
adapter->tx_pool = NULL;
+ adapter->num_active_tx_pools = 0;
}
static int init_tx_pools(struct net_device *netdev)
@@ -619,6 +641,8 @@ static int init_tx_pools(struct net_device *netdev)
if (!adapter->tx_pool)
return -1;
+ adapter->num_active_tx_pools = 0;
+
for (i = 0; i < tx_subcrqs; i++) {
tx_pool = &adapter->tx_pool[i];
@@ -666,6 +690,8 @@ static int init_tx_pools(struct net_device *netdev)
tx_pool->producer_index = 0;
}
+ adapter->num_active_tx_pools = tx_subcrqs;
+
return 0;
}
@@ -756,9 +782,27 @@ static int ibmvnic_login(struct net_device *netdev)
}
} while (adapter->renegotiate);
+ /* handle pending MAC address changes after successful login */
+ if (adapter->mac_change_pending) {
+ __ibmvnic_set_mac(netdev, &adapter->desired.mac);
+ adapter->mac_change_pending = false;
+ }
+
return 0;
}
+static void release_login_buffer(struct ibmvnic_adapter *adapter)
+{
+ kfree(adapter->login_buf);
+ adapter->login_buf = NULL;
+}
+
+static void release_login_rsp_buffer(struct ibmvnic_adapter *adapter)
+{
+ kfree(adapter->login_rsp_buf);
+ adapter->login_rsp_buf = NULL;
+}
+
static void release_resources(struct ibmvnic_adapter *adapter)
{
int i;
@@ -781,6 +825,10 @@ static void release_resources(struct ibmvnic_adapter *adapter)
}
}
}
+ kfree(adapter->napi);
+ adapter->napi = NULL;
+
+ release_login_rsp_buffer(adapter);
}
static int set_link_state(struct ibmvnic_adapter *adapter, u8 link_state)
@@ -854,7 +902,7 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
if (adapter->vpd->buff)
len = adapter->vpd->len;
- reinit_completion(&adapter->fw_done);
+ init_completion(&adapter->fw_done);
crq.get_vpd_size.first = IBMVNIC_CRQ_CMD;
crq.get_vpd_size.cmd = GET_VPD_SIZE;
ibmvnic_send_crq(adapter, &crq);
@@ -881,6 +929,7 @@ static int ibmvnic_get_vpd(struct ibmvnic_adapter *adapter)
if (dma_mapping_error(dev, adapter->vpd->dma_addr)) {
dev_err(dev, "Could not map VPD buffer\n");
kfree(adapter->vpd->buff);
+ adapter->vpd->buff = NULL;
return -ENOMEM;
}
@@ -916,6 +965,13 @@ static int init_resources(struct ibmvnic_adapter *adapter)
if (!adapter->vpd)
return -ENOMEM;
+ /* Vital Product Data (VPD) */
+ rc = ibmvnic_get_vpd(adapter);
+ if (rc) {
+ netdev_err(netdev, "failed to initialize Vital Product Data (VPD)\n");
+ return rc;
+ }
+
adapter->map_id = 1;
adapter->napi = kcalloc(adapter->req_rx_queues,
sizeof(struct napi_struct), GFP_KERNEL);
@@ -989,15 +1045,10 @@ static int __ibmvnic_open(struct net_device *netdev)
static int ibmvnic_open(struct net_device *netdev)
{
struct ibmvnic_adapter *adapter = netdev_priv(netdev);
- int rc, vpd;
+ int rc;
mutex_lock(&adapter->reset_lock);
- if (adapter->mac_change_pending) {
- __ibmvnic_set_mac(netdev, &adapter->desired.mac);
- adapter->mac_change_pending = false;
- }
-
if (adapter->state != VNIC_CLOSED) {
rc = ibmvnic_login(netdev);
if (rc) {
@@ -1017,16 +1068,40 @@ static int ibmvnic_open(struct net_device *netdev)
rc = __ibmvnic_open(netdev);
netif_carrier_on(netdev);
- /* Vital Product Data (VPD) */
- vpd = ibmvnic_get_vpd(adapter);
- if (vpd)
- netdev_err(netdev, "failed to initialize Vital Product Data (VPD)\n");
-
mutex_unlock(&adapter->reset_lock);
return rc;
}
+static void clean_rx_pools(struct ibmvnic_adapter *adapter)
+{
+ struct ibmvnic_rx_pool *rx_pool;
+ u64 rx_entries;
+ int rx_scrqs;
+ int i, j;
+
+ if (!adapter->rx_pool)
+ return;
+
+ rx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_rxadd_subcrqs);
+ rx_entries = adapter->req_rx_add_entries_per_subcrq;
+
+ /* Free any remaining skbs in the rx buffer pools */
+ for (i = 0; i < rx_scrqs; i++) {
+ rx_pool = &adapter->rx_pool[i];
+ if (!rx_pool)
+ continue;
+
+ netdev_dbg(adapter->netdev, "Cleaning rx_pool[%d]\n", i);
+ for (j = 0; j < rx_entries; j++) {
+ if (rx_pool->rx_buff[j].skb) {
+ dev_kfree_skb_any(rx_pool->rx_buff[j].skb);
+ rx_pool->rx_buff[j].skb = NULL;
+ }
+ }
+ }
+}
+
static void clean_tx_pools(struct ibmvnic_adapter *adapter)
{
struct ibmvnic_tx_pool *tx_pool;
@@ -1104,7 +1179,7 @@ static int __ibmvnic_close(struct net_device *netdev)
}
}
}
-
+ clean_rx_pools(adapter);
clean_tx_pools(adapter);
adapter->state = VNIC_CLOSED;
return rc;
@@ -1153,6 +1228,9 @@ static int build_hdr_data(u8 hdr_field, struct sk_buff *skb,
hdr_len[2] = tcp_hdrlen(skb);
else if (ipv6_hdr(skb)->nexthdr == IPPROTO_UDP)
hdr_len[2] = sizeof(struct udphdr);
+ } else if (skb->protocol == htons(ETH_P_ARP)) {
+ hdr_len[1] = arp_hdr_len(skb->dev);
+ hdr_len[2] = 0;
}
memset(hdr_data, 0, 120);
@@ -1275,6 +1353,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
unsigned char *dst;
u64 *handle_array;
int index = 0;
+ u8 proto = 0;
int ret = 0;
if (adapter->resetting) {
@@ -1363,17 +1442,18 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
}
if (skb->protocol == htons(ETH_P_IP)) {
- if (ip_hdr(skb)->version == 4)
- tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_IPV4;
- else if (ip_hdr(skb)->version == 6)
- tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_IPV6;
-
- if (ip_hdr(skb)->protocol == IPPROTO_TCP)
- tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_TCP;
- else if (ip_hdr(skb)->protocol != IPPROTO_TCP)
- tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_UDP;
+ tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_IPV4;
+ proto = ip_hdr(skb)->protocol;
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_IPV6;
+ proto = ipv6_hdr(skb)->nexthdr;
}
+ if (proto == IPPROTO_TCP)
+ tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_TCP;
+ else if (proto == IPPROTO_UDP)
+ tx_crq.v1.flags1 |= IBMVNIC_TX_PROT_UDP;
+
if (skb->ip_summed == CHECKSUM_PARTIAL) {
tx_crq.v1.flags1 |= IBMVNIC_TX_CHKSUM_OFFLOAD;
hdrs += 2;
@@ -1384,9 +1464,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev)
hdrs += 2;
}
/* determine if l2/3/4 headers are sent to firmware */
- if ((*hdrs >> 7) & 1 &&
- (skb->protocol == htons(ETH_P_IP) ||
- skb->protocol == htons(ETH_P_IPV6))) {
+ if ((*hdrs >> 7) & 1) {
build_hdr_descs_arr(tx_buff, &num_entries, *hdrs);
tx_crq.v1.n_crq_elem = num_entries;
tx_buff->indir_arr[0] = tx_crq;
@@ -1517,25 +1595,29 @@ static int __ibmvnic_set_mac(struct net_device *netdev, struct sockaddr *p)
crq.change_mac_addr.first = IBMVNIC_CRQ_CMD;
crq.change_mac_addr.cmd = CHANGE_MAC_ADDR;
ether_addr_copy(&crq.change_mac_addr.mac_addr[0], addr->sa_data);
+
+ init_completion(&adapter->fw_done);
ibmvnic_send_crq(adapter, &crq);
+ wait_for_completion(&adapter->fw_done);
/* netdev->dev_addr is changed in handle_change_mac_rsp function */
- return 0;
+ return adapter->fw_done_rc ? -EIO : 0;
}
static int ibmvnic_set_mac(struct net_device *netdev, void *p)
{
struct ibmvnic_adapter *adapter = netdev_priv(netdev);
struct sockaddr *addr = p;
+ int rc;
- if (adapter->state != VNIC_OPEN) {
+ if (adapter->state == VNIC_PROBED) {
memcpy(&adapter->desired.mac, addr, sizeof(struct sockaddr));
adapter->mac_change_pending = true;
return 0;
}
- __ibmvnic_set_mac(netdev, addr);
+ rc = __ibmvnic_set_mac(netdev, addr);
- return 0;
+ return rc;
}
/**
@@ -1545,6 +1627,7 @@ static int ibmvnic_set_mac(struct net_device *netdev, void *p)
static int do_reset(struct ibmvnic_adapter *adapter,
struct ibmvnic_rwi *rwi, u32 reset_state)
{
+ u64 old_num_rx_queues, old_num_tx_queues;
struct net_device *netdev = adapter->netdev;
int i, rc;
@@ -1554,6 +1637,9 @@ static int do_reset(struct ibmvnic_adapter *adapter,
netif_carrier_off(netdev);
adapter->reset_reason = rwi->reset_reason;
+ old_num_rx_queues = adapter->req_rx_queues;
+ old_num_tx_queues = adapter->req_tx_queues;
+
if (rwi->reset_reason == VNIC_RESET_MOBILITY) {
rc = ibmvnic_reenable_crq_queue(adapter);
if (rc)
@@ -1598,6 +1684,13 @@ static int do_reset(struct ibmvnic_adapter *adapter,
rc = init_resources(adapter);
if (rc)
return rc;
+ } else if (adapter->req_rx_queues != old_num_rx_queues ||
+ adapter->req_tx_queues != old_num_tx_queues) {
+ adapter->map_id = 1;
+ release_rx_pools(adapter);
+ release_tx_pools(adapter);
+ init_rx_pools(netdev);
+ init_tx_pools(netdev);
} else {
rc = reset_tx_pools(adapter);
if (rc)
@@ -1622,8 +1715,6 @@ static int do_reset(struct ibmvnic_adapter *adapter,
return 0;
}
- netif_carrier_on(netdev);
-
/* kick napi */
for (i = 0; i < adapter->req_rx_queues; i++)
napi_schedule(&adapter->napi[i]);
@@ -1631,6 +1722,8 @@ static int do_reset(struct ibmvnic_adapter *adapter,
if (adapter->reset_reason != VNIC_RESET_FAILOVER)
netdev_notify_peers(netdev);
+ netif_carrier_on(netdev);
+
return 0;
}
@@ -1786,7 +1879,8 @@ restart_poll:
u16 offset;
u8 flags = 0;
- if (unlikely(adapter->resetting)) {
+ if (unlikely(adapter->resetting &&
+ adapter->reset_reason != VNIC_RESET_NON_FATAL)) {
enable_scrq_irq(adapter, adapter->rx_scrq[scrq_num]);
napi_complete_done(napi, frames_processed);
return frames_processed;
@@ -1804,6 +1898,12 @@ restart_poll:
be16_to_cpu(next->rx_comp.rc));
/* free the entry */
next->rx_comp.first = 0;
+ dev_kfree_skb_any(rx_buff->skb);
+ remove_buff_from_pool(adapter, rx_buff);
+ continue;
+ } else if (!rx_buff->skb) {
+ /* free the entry */
+ next->rx_comp.first = 0;
remove_buff_from_pool(adapter, rx_buff);
continue;
}
@@ -2448,6 +2548,12 @@ static irqreturn_t ibmvnic_interrupt_rx(int irq, void *instance)
struct ibmvnic_sub_crq_queue *scrq = instance;
struct ibmvnic_adapter *adapter = scrq->adapter;
+ /* When booting a kdump kernel we can hit pending interrupts
+ * prior to completing driver initialization.
+ */
+ if (unlikely(adapter->state != VNIC_OPEN))
+ return IRQ_NONE;
+
adapter->rx_stats_buffers[scrq->scrq_num].interrupts++;
if (napi_schedule_prep(&adapter->napi[scrq->scrq_num])) {
@@ -2857,8 +2963,12 @@ static int ibmvnic_send_crq(struct ibmvnic_adapter *adapter,
cpu_to_be64(u64_crq[1]));
if (rc) {
- if (rc == H_CLOSED)
+ if (rc == H_CLOSED) {
dev_warn(dev, "CRQ Queue closed\n");
+ if (adapter->resetting)
+ ibmvnic_reset(adapter, VNIC_RESET_FATAL);
+ }
+
dev_warn(dev, "Send error (rc=%d)\n", rc);
}
@@ -2954,6 +3064,7 @@ static void send_login(struct ibmvnic_adapter *adapter)
struct vnic_login_client_data *vlcd;
int i;
+ release_login_rsp_buffer(adapter);
client_data_len = vnic_client_data_len(adapter);
buffer_size =
@@ -3235,7 +3346,7 @@ static void handle_vpd_rsp(union ibmvnic_crq *crq,
struct ibmvnic_adapter *adapter)
{
struct device *dev = &adapter->vdev->dev;
- unsigned char *substr = NULL, *ptr = NULL;
+ unsigned char *substr = NULL;
u8 fw_level_len = 0;
memset(adapter->fw_version, 0, 32);
@@ -3254,7 +3365,7 @@ static void handle_vpd_rsp(union ibmvnic_crq *crq,
*/
substr = strnstr(adapter->vpd->buff, "RM", adapter->vpd->len);
if (!substr) {
- dev_info(dev, "No FW level provided by VPD\n");
+ dev_info(dev, "Warning - No FW level has been provided in the VPD buffer by the VIOS Server\n");
goto complete;
}
@@ -3269,16 +3380,14 @@ static void handle_vpd_rsp(union ibmvnic_crq *crq,
/* copy firmware version string from vpd into adapter */
if ((substr + 3 + fw_level_len) <
(adapter->vpd->buff + adapter->vpd->len)) {
- ptr = strncpy((char *)adapter->fw_version,
- substr + 3, fw_level_len);
-
- if (!ptr)
- dev_err(dev, "Failed to isolate FW level string\n");
+ strncpy((char *)adapter->fw_version, substr + 3, fw_level_len);
} else {
dev_info(dev, "FW substr extrapolated VPD buff\n");
}
complete:
+ if (adapter->fw_version[0] == '\0')
+ strncpy((char *)adapter->fw_version, "N/A", 3 * sizeof(char));
complete(&adapter->fw_done);
}
@@ -3345,7 +3454,11 @@ static void handle_query_ip_offload_rsp(struct ibmvnic_adapter *adapter)
return;
}
+ adapter->ip_offload_ctrl.len =
+ cpu_to_be32(sizeof(adapter->ip_offload_ctrl));
adapter->ip_offload_ctrl.version = cpu_to_be32(INITIAL_VERSION_IOB);
+ adapter->ip_offload_ctrl.ipv4_chksum = buf->ipv4_chksum;
+ adapter->ip_offload_ctrl.ipv6_chksum = buf->ipv6_chksum;
adapter->ip_offload_ctrl.tcp_ipv4_chksum = buf->tcp_ipv4_chksum;
adapter->ip_offload_ctrl.udp_ipv4_chksum = buf->udp_ipv4_chksum;
adapter->ip_offload_ctrl.tcp_ipv6_chksum = buf->tcp_ipv6_chksum;
@@ -3518,8 +3631,8 @@ static void handle_error_indication(union ibmvnic_crq *crq,
ibmvnic_reset(adapter, VNIC_RESET_NON_FATAL);
}
-static void handle_change_mac_rsp(union ibmvnic_crq *crq,
- struct ibmvnic_adapter *adapter)
+static int handle_change_mac_rsp(union ibmvnic_crq *crq,
+ struct ibmvnic_adapter *adapter)
{
struct net_device *netdev = adapter->netdev;
struct device *dev = &adapter->vdev->dev;
@@ -3528,10 +3641,13 @@ static void handle_change_mac_rsp(union ibmvnic_crq *crq,
rc = crq->change_mac_addr_rsp.rc.code;
if (rc) {
dev_err(dev, "Error %ld in CHANGE_MAC_ADDR_RSP\n", rc);
- return;
+ goto out;
}
memcpy(netdev->dev_addr, &crq->change_mac_addr_rsp.mac_addr[0],
ETH_ALEN);
+out:
+ complete(&adapter->fw_done);
+ return rc;
}
static void handle_request_cap_rsp(union ibmvnic_crq *crq,
@@ -3585,7 +3701,17 @@ static void handle_request_cap_rsp(union ibmvnic_crq *crq,
*req_value,
(long int)be64_to_cpu(crq->request_capability_rsp.
number), name);
- *req_value = be64_to_cpu(crq->request_capability_rsp.number);
+
+ if (be16_to_cpu(crq->request_capability_rsp.capability) ==
+ REQ_MTU) {
+ pr_err("mtu of %llu is not supported. Reverting.\n",
+ *req_value);
+ *req_value = adapter->fallback.mtu;
+ } else {
+ *req_value =
+ be64_to_cpu(crq->request_capability_rsp.number);
+ }
+
ibmvnic_send_req_caps(adapter, 1);
return;
default:
@@ -3664,6 +3790,7 @@ static int handle_login_rsp(union ibmvnic_crq *login_rsp_crq,
ibmvnic_remove(adapter->vdev);
return -EIO;
}
+ release_login_buffer(adapter);
complete(&adapter->init_done);
return 0;
@@ -3981,7 +4108,7 @@ static void ibmvnic_handle_crq(union ibmvnic_crq *crq,
break;
case CHANGE_MAC_ADDR_RSP:
netdev_dbg(netdev, "Got MAC address change Response\n");
- handle_change_mac_rsp(crq, adapter);
+ adapter->fw_done_rc = handle_change_mac_rsp(crq, adapter);
break;
case ERROR_INDICATION:
netdev_dbg(netdev, "Got Error Indication\n");
@@ -4285,7 +4412,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
}
netdev = alloc_etherdev_mq(sizeof(struct ibmvnic_adapter),
- IBMVNIC_MAX_TX_QUEUES);
+ IBMVNIC_MAX_QUEUES);
if (!netdev)
return -ENOMEM;
@@ -4411,7 +4538,7 @@ static ssize_t failover_store(struct device *dev, struct device_attribute *attr,
return count;
}
-static DEVICE_ATTR(failover, 0200, NULL, failover_store);
+static DEVICE_ATTR_WO(failover);
static unsigned long ibmvnic_get_desired_dma(struct vio_dev *vdev)
{