drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent()
We don't need to hold the spinlock while zeroing the allocated memory.
In case we handle big buffers this is a severe issue as other CPUs might
be spinning half a second or longer.
Signed-off-by: Bastian Hecht <bhecht@de.adit-jv.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Mark Craske <Mark_Craske@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index 2789f7a..640a7e6 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -165,6 +165,7 @@
int order = get_order(size);
unsigned long flags;
int pageno;
+ int dma_memory_map;
if (!dev)
return 0;
@@ -187,11 +188,12 @@
*/
*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
*ret = mem->virt_base + (pageno << PAGE_SHIFT);
- if (mem->flags & DMA_MEMORY_MAP)
+ dma_memory_map = (mem->flags & DMA_MEMORY_MAP);
+ spin_unlock_irqrestore(&mem->spinlock, flags);
+ if (dma_memory_map)
memset(*ret, 0, size);
else
memset_io(*ret, 0, size);
- spin_unlock_irqrestore(&mem->spinlock, flags);
return 1;