dma: Define dma_context_memory and use in sysbus-ohci

Define a new global dma_context_memory which is a DMAContext corresponding
to the global address_space_memory AddressSpace. This can be used by
sysbus peripherals like sysbus-ohci which need to do DMA.

In particular, use it in the sysbus-ohci device, which fixes a
segfault when attempting to use that device.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/dma.h b/dma.h
index 91ccdb5eac..eedf878383 100644
--- a/dma.h
+++ b/dma.h
@@ -68,6 +68,11 @@ struct DMAContext {
     DMAUnmapFunc *unmap;
 };
 
+/* A global DMA context corresponding to the address_space_memory
+ * AddressSpace, for sysbus devices which do DMA.
+ */
+extern DMAContext dma_context_memory;
+
 static inline void dma_barrier(DMAContext *dma, DMADirection dir)
 {
     /*