[PATCH 093/117] Staging: hv: netvsc: Get rid of release_outbound_net_device() by inlining the code

K. Y. Srinivasan
2011-07-15T17:36:17Z

Get rid of release_outbound_net_device() by inlining the code.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/netvsc.c | 45 ++++++++++++++++--------------------------
1 files changed, 17 insertions(+), 28 deletions(-)

diff --git a/drivers/staging/hv/netvsc.c b/drivers/staging/hv/netvsc.c
index 7c3d7ac..3975219 100644
--- a/drivers/staging/hv/netvsc.c
+++ b/drivers/staging/hv/netvsc.c
@@ -98,28 +98,6 @@ static void put_net_device(struct hv_device *device)
spin_unlock_irqrestore(&device->ext_lock, flags);
}

-static struct netvsc_device *release_outbound_net_device(
- struct hv_device *device)
-{
- struct netvsc_device *net_device;
- unsigned long flags;
-
- spin_lock_irqsave(&device->ext_lock, flags);
- net_device = device->ext;
- if (net_device == NULL) {
- spin_unlock_irqrestore(&device->ext_lock, flags);
- return NULL;
- }
-
- spin_unlock_irqrestore(&device->ext_lock, flags);
-
- /* Busy wait until the ref drop to 2, then set it to 1 */
- while (atomic_cmpxchg(&net_device->refcnt, 2, 1) != 2)
- udelay(100);
-
- return net_device;
-}
-
static struct netvsc_device *release_inbound_net_device(
struct hv_device *device)
{
@@ -424,13 +402,13 @@ int netvsc_device_remove(struct hv_device *device)
unsigned long flags;

- /* Stop outbound traffic ie sends and receives completions */
- net_device = release_outbound_net_device(device);
- if (!net_device) {
- dev_err(&device->device, "No net device present!!");
+ spin_lock_irqsave(&device->ext_lock, flags);
+ net_device = (struct netvsc_device *)device->ext;
+ if (net_device == NULL) {
+ spin_unlock_irqrestore(&device->ext_lock, flags);
return -ENODEV;
}
- spin_lock_irqsave(&device->ext_lock, flags);
+ atomic_dec(&net_device->refcnt);
net_device->destroy = true;
spin_unlock_irqrestore(&device->ext_lock, flags);

@@ -448,6 +426,18 @@ int netvsc_device_remove(struct hv_device *device)
/* Stop inbound traffic ie receives and sends completions */
net_device = release_inbound_net_device(device);

+ /*
+ * Wait until the ref cnt falls to 0.
+ * We have already stopped any new references
+ * for outgoing traffic. Also, at this point we don't have any
+ * incoming traffic as well. So this must be outgoing refrences
+ * established prior to marking the device as being destroyed.
+ * Since the send path is non-blocking, it is reasonable to busy
+ * wait here.
+ */
+ while (atomic_read(&net_device->refcnt))
+ udelay(100);
+
/* At this point, no one should be accessing netDevice except in here */
dev_notice(&device->device, "net device safe to remove");

@@ -1000,7 +990,6 @@ cleanup:
kfree(packet);
}

- release_outbound_net_device(device);
release_inbound_net_device(device);

kfree(net_device);
--
1.7.4.1