[PATCH 6/8] net: thunderx: add mutex to protect mailbox from concurrent calls for same VF

Vadim Lomovtsev
2019-02-06T10:22:06Z

In some cases it could happen that nicvf_send_msg_to_pf() could be called
concurrently for the same NIC VF, and thus re-writing mailbox contents and
breaking messaging sequence with PF by re-writing NICVF data.

This commit is to implement mutex for NICVF to protect mailbox registers
and NICVF messaging control data from concurrent access.

Signed-off-by: Vadim Lomovtsev <vlomovtsev@marvell.com>
---
drivers/net/ethernet/cavium/thunder/nic.h | 2 ++
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 13 ++++++++++---
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 227343625e83..86cda3f4b37b 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -329,6 +329,8 @@ struct nicvf {
spinlock_t rx_mode_wq_lock;
/* workqueue for handling kernel ndo_set_rx_mode() calls */
struct workqueue_struct *nicvf_rx_mode_wq;
+ /* mutex to protect VF's mailbox contents from concurrent access */
+ struct mutex rx_mode_mtx;

/* PTP timestamp */
struct cavium_ptp *ptp_clock;
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 30c7f54b4f17..a05e2989ec76 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -124,6 +124,9 @@ int nicvf_send_msg_to_pf(struct nicvf *nic, union nic_mbx *mbx)
{
int timeout = NIC_MBOX_MSG_TIMEOUT;
int sleep = 10;
+ int ret = 0;
+
+ mutex_lock(&nic->rx_mode_mtx);

nic->pf_acked = false;
nic->pf_nacked = false;
@@ -136,7 +139,8 @@ int nicvf_send_msg_to_pf(struct nicvf *nic, union nic_mbx *mbx)
netdev_err(nic->netdev,
"PF NACK to mbox msg 0x%02x from VF%d\n",
(mbx->msg.msg & 0xFF), nic->vf_id);
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
msleep(sleep);
if (nic->pf_acked)
@@ -146,10 +150,12 @@ int nicvf_send_msg_to_pf(struct nicvf *nic, union nic_mbx *mbx)
netdev_err(nic->netdev,
"PF didn't ACK to mbox msg 0x%02x from VF%d\n",
(mbx->msg.msg & 0xFF), nic->vf_id);
- return -EBUSY;
+ ret = -EBUSY;
+ break;
}
}
- return 0;
+ mutex_unlock(&nic->rx_mode_mtx);
+ return ret;
}

/* Checks if VF is able to comminicate with PF
@@ -2211,6 +2217,7 @@ static int nicvf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
nic->vf_id);
INIT_WORK(&nic->rx_mode_work.work, nicvf_set_rx_mode_task);
spin_lock_init(&nic->rx_mode_wq_lock);
+ mutex_init(&nic->rx_mode_mtx);

err = register_netdev(netdev);
if (err) {