sfc: save old MAC address in case sriov_mac_address_changed fails

Otherwise the PF and VF can disagree on the VF's MAC address and
this leads to strange behaviour, up to and including kernel panics.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/ef10_sriov.h b/drivers/net/ethernet/sfc/ef10_sriov.h
index 86bac7e..8b67163 100644 (file)
--- a/drivers/net/ethernet/sfc/ef10_sriov.h
+++ b/drivers/net/ethernet/sfc/ef10_sriov.h
@@ -31,7 +31,10 @@ static inline bool efx_ef10_sriov_wanted(struct efx_nic *efx)
 
 int efx_ef10_sriov_configure(struct efx_nic *efx, int num_vfs);
 int efx_ef10_sriov_init(struct efx_nic *efx);
-static inline void efx_ef10_sriov_mac_address_changed(struct efx_nic *efx) {}
+static inline int efx_ef10_sriov_mac_address_changed(struct efx_nic *efx)
+{
+       return -EOPNOTSUPP;
+}
 static inline void efx_ef10_sriov_reset(struct efx_nic *efx) {}
 void efx_ef10_sriov_fini(struct efx_nic *efx);
 static inline void efx_ef10_sriov_flr(struct efx_nic *efx, unsigned vf_i) {}

diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 0f127a0..864c337 100644 (file)
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -2196,6 +2196,8 @@ static int efx_set_mac_address(struct net_device *net_dev, void *data)
        struct efx_nic *efx = netdev_priv(net_dev);
        struct sockaddr *addr = data;
        u8 *new_addr = addr->sa_data;
+       u8 old_addr[6];
+       int rc;
 
        if (!is_valid_ether_addr(new_addr)) {
                netif_err(efx, drv, efx->net_dev,
@@ -2204,9 +2206,16 @@ static int efx_set_mac_address(struct net_device *net_dev, void *data)
                return -EADDRNOTAVAIL;
        }
 
+       /* save old address */
+       ether_addr_copy(old_addr, net_dev->dev_addr);
        ether_addr_copy(net_dev->dev_addr, new_addr);
-       if (efx->type->sriov_mac_address_changed)
-               efx->type->sriov_mac_address_changed(efx);
+       if (efx->type->sriov_mac_address_changed) {
+               rc = efx->type->sriov_mac_address_changed(efx);
+               if (rc) {
+                       ether_addr_copy(net_dev->dev_addr, old_addr);
+                       return rc;
+               }
+       }
 
        /* Reconfigure the MAC */
        mutex_lock(&efx->mac_lock);

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 031a338..55a5f48 100644 (file)
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1334,7 +1334,7 @@ struct efx_nic_type {
        int (*sriov_configure)(struct efx_nic *efx, int num_vfs);
        int (*sriov_init)(struct efx_nic *efx);
        void (*sriov_fini)(struct efx_nic *efx);
-       void (*sriov_mac_address_changed)(struct efx_nic *efx);
+       int (*sriov_mac_address_changed)(struct efx_nic *efx);
        bool (*sriov_wanted)(struct efx_nic *efx);
        void (*sriov_reset)(struct efx_nic *efx);
        void (*sriov_flr)(struct efx_nic *efx, unsigned vf_i);

diff --git a/drivers/net/ethernet/sfc/siena_sriov.c b/drivers/net/ethernet/sfc/siena_sriov.c
index 2a5f352..da7b94f 100644 (file)
--- a/drivers/net/ethernet/sfc/siena_sriov.c
+++ b/drivers/net/ethernet/sfc/siena_sriov.c
@@ -1476,16 +1476,18 @@ void efx_siena_sriov_flr(struct efx_nic *efx, unsigned vf_i)
        vf->evq0_count = 0;
 }
 
-void efx_siena_sriov_mac_address_changed(struct efx_nic *efx)
+int efx_siena_sriov_mac_address_changed(struct efx_nic *efx)
 {
        struct siena_nic_data *nic_data = efx->nic_data;
        struct vfdi_status *vfdi_status = nic_data->vfdi_status.addr;
 
        if (!efx->vf_init_count)
-               return;
+               return 0;
        ether_addr_copy(vfdi_status->peers[0].mac_addr,
                        efx->net_dev->dev_addr);
        queue_work(vfdi_workqueue, &nic_data->peer_work);
+
+       return 0;
 }
 
 void efx_siena_sriov_tx_flush_done(struct efx_nic *efx, efx_qword_t *event)

diff --git a/drivers/net/ethernet/sfc/siena_sriov.h b/drivers/net/ethernet/sfc/siena_sriov.h
index 64e3e01..d88d4da 100644 (file)
--- a/drivers/net/ethernet/sfc/siena_sriov.h
+++ b/drivers/net/ethernet/sfc/siena_sriov.h
@@ -44,7 +44,7 @@
 int efx_siena_sriov_configure(struct efx_nic *efx, int num_vfs);
 int efx_siena_sriov_init(struct efx_nic *efx);
 void efx_siena_sriov_fini(struct efx_nic *efx);
-void efx_siena_sriov_mac_address_changed(struct efx_nic *efx);
+int efx_siena_sriov_mac_address_changed(struct efx_nic *efx);
 bool efx_siena_sriov_wanted(struct efx_nic *efx);
 void efx_siena_sriov_reset(struct efx_nic *efx);
 void efx_siena_sriov_flr(struct efx_nic *efx, unsigned flr);