net_dma: acquire/release dma channels on ifup/ifdown
The recent dmaengine rework removed the capability to remove dma device
driver modules while net_dma is active. Rather than notify
dmaengine-clients that channels are trying to be removed, we now rely on
clients to notify dmaengine when they no longer have a need for
channels. Teach net_dma to release channels by taking dmaengine
references at netdevice open and dropping references at netdevice close.
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 5f736f1..b715a55 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1088,6 +1088,11 @@
dev->flags |= IFF_UP;
/*
+ * Enable NET_DMA
+ */
+ dmaengine_get();
+
+ /*
* Initialize multicasting status
*/
dev_set_rx_mode(dev);
@@ -1164,6 +1169,11 @@
*/
call_netdevice_notifiers(NETDEV_DOWN, dev);
+ /*
+ * Shutdown NET_DMA
+ */
+ dmaengine_put();
+
return 0;
}
@@ -5151,9 +5161,6 @@
hotcpu_notifier(dev_cpu_callback, 0);
dst_init();
dev_mcast_init();
- #ifdef CONFIG_NET_DMA
- dmaengine_get();
- #endif
rc = 0;
out:
return rc;