[PATCH 095/117] Staging: hv: netvsc: Leverage the spinlock to manage refcnt

K. Y. Srinivasan
2011-07-15T17:36:15Z

Now that we have a spin lock protecting the device pointer, use it to also
protect the refrence count.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/hyperv_net.h | 2 +-
drivers/staging/hv/netvsc.c | 18 +++++++++---------
2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/hv/hyperv_net.h b/drivers/staging/hv/hyperv_net.h
index 0b347c1..5c8fc31 100644
--- a/drivers/staging/hv/hyperv_net.h
+++ b/drivers/staging/hv/hyperv_net.h
@@ -369,7 +369,7 @@ struct nvsp_message {
struct netvsc_device {
struct hv_device *dev;

- atomic_t refcnt;
+ int refcnt;
atomic_t num_outstanding_sends;
bool destroy;
/*
diff --git a/drivers/staging/hv/netvsc.c b/drivers/staging/hv/netvsc.c
index 0411332..3b234a3 100644
--- a/drivers/staging/hv/netvsc.c
+++ b/drivers/staging/hv/netvsc.c
@@ -41,7 +41,7 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device)
return NULL;

/* Set to 2 to allow both inbound and outbound traffic */
- atomic_set(&net_device->refcnt, 2);
+ net_device->refcnt = 2;

net_device->destroy = false;
net_device->dev = device;
@@ -58,9 +58,9 @@ static struct netvsc_device *get_outbound_net_device(struct hv_device *device)

spin_lock_irqsave(&device->ext_lock, flags);
net_device = device->ext;
- if (net_device && (atomic_read(&net_device->refcnt) > 1) &&
+ if (net_device && (net_device->refcnt > 1) &&
!net_device->destroy)
- atomic_inc(&net_device->refcnt);
+ net_device->refcnt++;
else
net_device = NULL;
spin_unlock_irqrestore(&device->ext_lock, flags);
@@ -76,8 +76,8 @@ static struct netvsc_device *get_inbound_net_device(struct hv_device *device)

spin_lock_irqsave(&device->ext_lock, flags);
net_device = device->ext;
- if (net_device && atomic_read(&net_device->refcnt))
- atomic_inc(&net_device->refcnt);
+ if (net_device && net_device->refcnt)
+ net_device->refcnt++;
else
net_device = NULL;

@@ -94,7 +94,7 @@ static void put_net_device(struct hv_device *device)

net_device = device->ext;

- atomic_dec(&net_device->refcnt);
+ net_device->refcnt--;
spin_unlock_irqrestore(&device->ext_lock, flags);
}

@@ -385,7 +385,7 @@ int netvsc_device_remove(struct hv_device *device)
spin_unlock_irqrestore(&device->ext_lock, flags);
return -ENODEV;
}
- atomic_dec(&net_device->refcnt);
+ net_device->refcnt--;
net_device->destroy = true;
spin_unlock_irqrestore(&device->ext_lock, flags);

@@ -401,7 +401,7 @@ int netvsc_device_remove(struct hv_device *device)
netvsc_disconnect_vsp(net_device);

spin_lock_irqsave(&device->ext_lock, flags);
- atomic_dec(&net_device->refcnt);
+ net_device->refcnt--;
device->ext = NULL;
spin_unlock_irqrestore(&device->ext_lock, flags);

@@ -414,7 +414,7 @@ int netvsc_device_remove(struct hv_device *device)
* Since the send path is non-blocking, it is reasonable to busy
* wait here.
*/
- while (atomic_read(&net_device->refcnt))
+ while (net_device->refcnt != 0)
udelay(100);

/* At this point, no one should be accessing netDevice except in here */
--
1.7.4.1