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/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 64dea2a..c73f1e2 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -270,8 +270,18 @@
/* --- public DMA engine API --- */
+#ifdef CONFIG_DMA_ENGINE
void dmaengine_get(void);
void dmaengine_put(void);
+#else
+static inline void dmaengine_get(void)
+{
+}
+static inline void dmaengine_put(void)
+{
+}
+#endif
+
dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
void *dest, void *src, size_t len);
dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,