Commit c7e9bc54 authored Oct 18, 2013 by Stefano Stabellini

arm/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain



We can't simply override arm_dma_ops with xen_dma_ops because devices
are allowed to have their own dma_ops and they take precedence over
arm_dma_ops. When running on Xen as initial domain, we always want
xen_dma_ops to be the one in use.

We introduce __generic_dma_ops to allow xen_dma_ops functions to call
back to the native implementation.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
CC: will.deacon@arm.com
CC: linux@arm.linux.org.uk

Changes in v7:
- return xen_dma_ops only if we are the initial domain;
- rename __get_dma_ops to __generic_dma_ops.

parent eb1ddc00

arch/arm/include/asm/dma-mapping.h

+12 −1

Original line number	Diff line number	Diff line
		@@ -12,17 +12,28 @@
		#include <asm/memory.h>
		#include <asm/cacheflush.h>

		#include <xen/xen.h>
		#include <asm/xen/hypervisor.h>

		#define DMA_ERROR_CODE (~0)
		extern struct dma_map_ops arm_dma_ops;
		extern struct dma_map_ops arm_coherent_dma_ops;

		static inline struct dma_map_ops get_dma_ops(struct device dev)
		static inline struct dma_map_ops __generic_dma_ops(struct device dev)
		{
		if (dev && dev->archdata.dma_ops)
		return dev->archdata.dma_ops;
		return &arm_dma_ops;
		}

		static inline struct dma_map_ops get_dma_ops(struct device dev)
		{
		if (xen_initial_domain())
		return xen_dma_ops;
		else
		return __generic_dma_ops(dev);
		}

		static inline void set_dma_ops(struct device dev, struct dma_map_ops ops)
		{
		BUG_ON(!dev);