From 649274d993212e7c23c0cb734572c2311c200872 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 11 Jan 2009 00:20:39 -0800 Subject: [PATCH] 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 Signed-off-by: Dan Williams Signed-off-by: David S. Miller --- include/linux/dmaengine.h | 10 ++++++++++ net/core/dev.c | 13 ++++++++++--- 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 64dea2ab326c..c73f1e2b59b7 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -270,8 +270,18 @@ struct dma_device { /* --- 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, diff --git a/net/core/dev.c b/net/core/dev.c index 5f736f1ceeae..b715a55cccc4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1087,6 +1087,11 @@ int dev_open(struct net_device *dev) */ dev->flags |= IFF_UP; + /* + * Enable NET_DMA + */ + dmaengine_get(); + /* * Initialize multicasting status */ @@ -1164,6 +1169,11 @@ int dev_close(struct net_device *dev) */ call_netdevice_notifiers(NETDEV_DOWN, dev); + /* + * Shutdown NET_DMA + */ + dmaengine_put(); + return 0; } @@ -5151,9 +5161,6 @@ static int __init net_dev_init(void) hotcpu_notifier(dev_cpu_callback, 0); dst_init(); dev_mcast_init(); - #ifdef CONFIG_NET_DMA - dmaengine_get(); - #endif rc = 0; out: return rc; -- 2.39.5