[PATCH 4.4 34/80] enic: handle mtu change for vf properly

From: Greg Kroah-Hartman
Date: Mon Sep 03 2018 - 12:54:40 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Govindarajulu Varadarajan <gvaradar@xxxxxxxxx>

[ Upstream commit ab123fe071c9aa9680ecd62eb080eb26cff4892c ]

When driver gets notification for mtu change, driver does not handle it for
all RQs. It handles only RQ[0].

Fix is to use enic_change_mtu() interface to change mtu for vf.

Signed-off-by: Govindarajulu Varadarajan <gvaradar@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/cisco/enic/enic_main.c | 78 +++++++++-------------------
1 file changed, 27 insertions(+), 51 deletions(-)

--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -1842,10 +1842,32 @@ static int enic_stop(struct net_device *
return 0;
}

+static int _enic_change_mtu(struct net_device *netdev, int new_mtu)
+{
+ bool running = netif_running(netdev);
+ int err = 0;
+
+ ASSERT_RTNL();
+ if (running) {
+ err = enic_stop(netdev);
+ if (err)
+ return err;
+ }
+
+ netdev->mtu = new_mtu;
+
+ if (running) {
+ err = enic_open(netdev);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
static int enic_change_mtu(struct net_device *netdev, int new_mtu)
{
struct enic *enic = netdev_priv(netdev);
- int running = netif_running(netdev);

if (new_mtu < ENIC_MIN_MTU || new_mtu > ENIC_MAX_MTU)
return -EINVAL;
@@ -1853,20 +1875,12 @@ static int enic_change_mtu(struct net_de
if (enic_is_dynamic(enic) || enic_is_sriov_vf(enic))
return -EOPNOTSUPP;

- if (running)
- enic_stop(netdev);
-
- netdev->mtu = new_mtu;
-
if (netdev->mtu > enic->port_mtu)
netdev_warn(netdev,
- "interface MTU (%d) set higher than port MTU (%d)\n",
- netdev->mtu, enic->port_mtu);
-
- if (running)
- enic_open(netdev);
+ "interface MTU (%d) set higher than port MTU (%d)\n",
+ netdev->mtu, enic->port_mtu);

- return 0;
+ return _enic_change_mtu(netdev, new_mtu);
}

static void enic_change_mtu_work(struct work_struct *work)
@@ -1874,47 +1888,9 @@ static void enic_change_mtu_work(struct
struct enic *enic = container_of(work, struct enic, change_mtu_work);
struct net_device *netdev = enic->netdev;
int new_mtu = vnic_dev_mtu(enic->vdev);
- int err;
- unsigned int i;
-
- new_mtu = max_t(int, ENIC_MIN_MTU, min_t(int, ENIC_MAX_MTU, new_mtu));

rtnl_lock();
-
- /* Stop RQ */
- del_timer_sync(&enic->notify_timer);
-
- for (i = 0; i < enic->rq_count; i++)
- napi_disable(&enic->napi[i]);
-
- vnic_intr_mask(&enic->intr[0]);
- enic_synchronize_irqs(enic);
- err = vnic_rq_disable(&enic->rq[0]);
- if (err) {
- rtnl_unlock();
- netdev_err(netdev, "Unable to disable RQ.\n");
- return;
- }
- vnic_rq_clean(&enic->rq[0], enic_free_rq_buf);
- vnic_cq_clean(&enic->cq[0]);
- vnic_intr_clean(&enic->intr[0]);
-
- /* Fill RQ with new_mtu-sized buffers */
- netdev->mtu = new_mtu;
- vnic_rq_fill(&enic->rq[0], enic_rq_alloc_buf);
- /* Need at least one buffer on ring to get going */
- if (vnic_rq_desc_used(&enic->rq[0]) == 0) {
- rtnl_unlock();
- netdev_err(netdev, "Unable to alloc receive buffers.\n");
- return;
- }
-
- /* Start RQ */
- vnic_rq_enable(&enic->rq[0]);
- napi_enable(&enic->napi[0]);
- vnic_intr_unmask(&enic->intr[0]);
- enic_notify_timer_start(enic);
-
+ (void)_enic_change_mtu(netdev, new_mtu);
rtnl_unlock();

netdev_info(netdev, "interface MTU set as %d\n", netdev->mtu);