Commit 0266ecb5 authored by Satish Kharat's avatar Satish Kharat Committed by Jakub Kicinski
Browse files

enic: make enic_dev_enable/disable ref-counted 



Both the data path (ndo_open/ndo_stop) and the upcoming admin channel
need to enable and disable the vNIC device independently. Without
reference counting, closing the admin channel while the netdev is up
would inadvertently disable the entire device.

Add an enable_count to struct enic, protected by the existing
devcmd_lock. enic_dev_enable() issues CMD_ENABLE_WAIT only on the
first caller (0 -> 1 transition), and enic_dev_disable() issues
CMD_DISABLE only when the last caller releases (1 -> 0 transition).

Also check the return value of enic_dev_enable() in enic_open() and
fail the open if the firmware enable command fails. Without this check,
a failed enable leaves enable_count at zero while the interface appears
up, which can cause a later admin channel enable/disable cycle to
incorrectly disable the hardware under the active data path.

Signed-off-by: default avatarSatish Kharat <satishkh@cisco.com>
Link: https://patch.msgid.link/20260401-enic-sriov-v2-prep-v4-4-d5834b2ef1b9@cisco.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 56a4d7a8

drivers/net/ethernet/cisco/enic/enic.h

+1 −0
Original line number Diff line number Diff line
@@ -260,6 +260,7 @@ struct enic { 
	u16 num_vfs;

#endif

	enum enic_vf_type vf_type;

	unsigned int enable_count;

	spinlock_t enic_api_lock;

	bool enic_api_busy;

	struct enic_port_profile *pp;

drivers/net/ethernet/cisco/enic/enic_dev.c

+13 −4
Original line number Diff line number Diff line
@@ -131,10 +131,13 @@ int enic_dev_set_ig_vlan_rewrite_mode(struct enic *enic) 


int enic_dev_enable(struct enic *enic)

{

	int err;

	int err = 0;



	spin_lock_bh(&enic->devcmd_lock);

	if (enic->enable_count == 0)

		err = vnic_dev_enable_wait(enic->vdev);

	if (!err)

		enic->enable_count++;

	spin_unlock_bh(&enic->devcmd_lock);



	return err;
@@ -142,9 +145,15 @@ int enic_dev_enable(struct enic *enic) 


int enic_dev_disable(struct enic *enic)

{

	int err;

	int err = 0;



	spin_lock_bh(&enic->devcmd_lock);

	if (enic->enable_count == 0) {

		spin_unlock_bh(&enic->devcmd_lock);

		return 0;

	}

	enic->enable_count--;

	if (enic->enable_count == 0)

		err = vnic_dev_disable(enic->vdev);

	spin_unlock_bh(&enic->devcmd_lock);

drivers/net/ethernet/cisco/enic/enic_main.c

+16 −1
Original line number Diff line number Diff line
@@ -1750,7 +1750,11 @@ static int enic_open(struct net_device *netdev) 
	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)

		for (i = 0; i < enic->wq_count; i++)

			napi_enable(&enic->napi[enic_cq_wq(enic, i)]);

	enic_dev_enable(enic);

	err = enic_dev_enable(enic);

	if (err) {

		netdev_err(netdev, "Failed to enable device: %d\n", err);

		goto err_out_dev_enable;

	}



	for (i = 0; i < enic->intr_count; i++)

		vnic_intr_unmask(&enic->intr[i]);
@@ -1760,6 +1764,17 @@ static int enic_open(struct net_device *netdev) 


	return 0;



err_out_dev_enable:

	for (i = 0; i < enic->rq_count; i++)

		napi_disable(&enic->napi[i]);

	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)

		for (i = 0; i < enic->wq_count; i++)

			napi_disable(&enic->napi[enic_cq_wq(enic, i)]);

	netif_tx_disable(netdev);

	if (!enic_is_dynamic(enic) && !enic_is_sriov_vf(enic))

		enic_dev_del_station_addr(enic);

	for (i = 0; i < enic->wq_count; i++)

		vnic_wq_disable(&enic->wq[i].vwq);

err_out_free_rq:

	for (i = 0; i < enic->rq_count; i++) {

		ret = vnic_rq_disable(&enic->rq[i].vrq);