netvsc: use refcount_t for keeping track of sub channels

Rather than a lock and variable, use a refcount_t to keep track
of the number of sub channels.  Don't need to wait for subchannels
on device removal since wait was already done in device_add.

Also fix the error handling; don't wait forever in case of
an error on request to create sub channels.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger 2017-03-22 14:51:02 -07:00 committed by David S. Miller
parent a0be450e19
commit 43c7bd1ffc
2 changed files with 12 additions and 33 deletions

View File

@ -761,8 +761,8 @@ struct netvsc_device {
u32 max_chn;
u32 num_chn;
spinlock_t sc_lock; /* Protects num_sc_offered variable */
u32 num_sc_offered;
refcount_t sc_offered;
/* Holds rndis device info */
void *extension;

View File

@ -997,7 +997,6 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
struct netvsc_device *nvscdev = net_device_to_netvsc_device(ndev);
u16 chn_index = new_sc->offermsg.offer.sub_channel_index;
struct netvsc_channel *nvchan;
unsigned long flags;
int ret;
if (chn_index >= nvscdev->num_chn)
@ -1019,10 +1018,7 @@ static void netvsc_sc_open(struct vmbus_channel *new_sc)
napi_enable(&nvchan->napi);
spin_lock_irqsave(&nvscdev->sc_lock, flags);
nvscdev->num_sc_offered--;
spin_unlock_irqrestore(&nvscdev->sc_lock, flags);
if (nvscdev->num_sc_offered == 0)
if (refcount_dec_and_test(&nvscdev->sc_offered))
complete(&nvscdev->channel_init_wait);
}
@ -1039,12 +1035,9 @@ int rndis_filter_device_add(struct hv_device *dev,
struct ndis_recv_scale_cap rsscap;
u32 rsscap_size = sizeof(struct ndis_recv_scale_cap);
unsigned int gso_max_size = GSO_MAX_SIZE;
u32 mtu, size;
u32 num_rss_qs;
u32 sc_delta;
u32 mtu, size, num_rss_qs;
const struct cpumask *node_cpu_mask;
u32 num_possible_rss_qs;
unsigned long flags;
int i, ret;
rndis_device = get_rndis_device();
@ -1067,7 +1060,7 @@ int rndis_filter_device_add(struct hv_device *dev,
net_device->max_chn = 1;
net_device->num_chn = 1;
spin_lock_init(&net_device->sc_lock);
refcount_set(&net_device->sc_offered, 0);
net_device->extension = rndis_device;
rndis_device->ndev = net;
@ -1204,6 +1197,7 @@ int rndis_filter_device_add(struct hv_device *dev,
if (num_rss_qs == 0)
return 0;
refcount_set(&net_device->sc_offered, num_rss_qs);
vmbus_set_sc_create_callback(dev->channel, netvsc_sc_open);
init_packet = &net_device->channel_init_pkt;
@ -1219,32 +1213,23 @@ int rndis_filter_device_add(struct hv_device *dev,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
if (ret)
goto out;
wait_for_completion(&net_device->channel_init_wait);
if (init_packet->msg.v5_msg.subchn_comp.status !=
NVSP_STAT_SUCCESS) {
if (init_packet->msg.v5_msg.subchn_comp.status != NVSP_STAT_SUCCESS) {
ret = -ENODEV;
goto out;
}
wait_for_completion(&net_device->channel_init_wait);
net_device->num_chn = 1 +
init_packet->msg.v5_msg.subchn_comp.num_subchannels;
ret = rndis_filter_set_rss_param(rndis_device, netvsc_hash_key,
/* ignore failues from setting rss parameters, still have channels */
rndis_filter_set_rss_param(rndis_device, netvsc_hash_key,
net_device->num_chn);
/*
* Set the number of sub-channels to be received.
*/
spin_lock_irqsave(&net_device->sc_lock, flags);
sc_delta = num_rss_qs - (net_device->num_chn - 1);
net_device->num_sc_offered -= sc_delta;
spin_unlock_irqrestore(&net_device->sc_lock, flags);
out:
if (ret) {
net_device->max_chn = 1;
net_device->num_chn = 1;
net_device->num_sc_offered = 0;
}
return 0; /* return 0 because primary channel can be used alone */
@ -1259,12 +1244,6 @@ void rndis_filter_device_remove(struct hv_device *dev,
{
struct rndis_device *rndis_dev = net_dev->extension;
/* If not all subchannel offers are complete, wait for them until
* completion to avoid race.
*/
if (net_dev->num_sc_offered > 0)
wait_for_completion(&net_dev->channel_init_wait);
/* Halt and release the rndis device */
rndis_filter_halt_device(rndis_dev);