xen/arm: remove xen_dma_ops

arm and arm64 can just use xen_swiotlb_dma_ops directly like x86, no
need for a pointer indirection.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJulien Grall <julien.grall@arm.com>
Reviewed-by: NStefano Stabellini <sstabellini@kernel.org>

arch/arm/mm/dma-mapping.c

@@ -36,6 +36,7 @@
 #include <asm/mach/map.h>
 #include <asm/system_info.h>
 #include <asm/dma-contiguous.h>
+#include <xen/swiotlb-xen.h>
 
 #include "dma.h"
 #include "mm.h"
@@ -2315,7 +2316,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 
 #ifdef CONFIG_XEN
 	if (xen_initial_domain())
-		dev->dma_ops = xen_dma_ops;
+		dev->dma_ops = &xen_swiotlb_dma_ops;
 #endif
 	dev->archdata.dma_ops_setup = true;
 }

arch/arm/xen/mm.c

@@ -162,16 +162,12 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
 }
 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
 
-const struct dma_map_ops *xen_dma_ops;
-EXPORT_SYMBOL(xen_dma_ops);
-
 int __init xen_mm_init(void)
 {
 	struct gnttab_cache_flush cflush;
 	if (!xen_initial_domain())
 		return 0;
 	xen_swiotlb_init(1, false);
-	xen_dma_ops = &xen_swiotlb_dma_ops;
 
 	cflush.op = 0;
 	cflush.a.dev_bus_addr = 0;

arch/arm64/mm/dma-mapping.c

@@ -8,6 +8,7 @@
 #include <linux/cache.h>
 #include <linux/dma-noncoherent.h>
 #include <linux/dma-iommu.h>
+#include <xen/swiotlb-xen.h>
 
 #include <asm/cacheflush.h>
 
@@ -52,6 +53,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 
 #ifdef CONFIG_XEN
 	if (xen_initial_domain())
-		dev->dma_ops = xen_dma_ops;
+		dev->dma_ops = &xen_swiotlb_dma_ops;
 #endif
 }

include/xen/arm/hypervisor.h

@@ -19,8 +19,6 @@ static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
 	return PARAVIRT_LAZY_NONE;
 }
 
-extern const struct dma_map_ops *xen_dma_ops;
-
 #ifdef CONFIG_XEN
 void __init xen_early_init(void);
 #else