[RFC PATCH 5/6] arm/xen: Introduce xen_setup_dma_ops()

[Oleksandr Tyshchenko <olekstysh@gmail.com>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

This patch introduces new helper and places it in new header.
The helper's purpose is to assign any Xen specific DMA ops in
a single place. For now, we deal with xen-swiotlb DMA ops only.
The subsequent patch will add xen-virtio DMA ops case.

Also re-use the xen_swiotlb_detect() check on Arm32.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
 arch/arm/include/asm/xen/xen-ops.h   |  1 +
 arch/arm/mm/dma-mapping.c            |  5 ++---
 arch/arm64/include/asm/xen/xen-ops.h |  1 +
 arch/arm64/mm/dma-mapping.c          |  5 ++---
 include/xen/arm/xen-ops.h            | 13 +++++++++++++
 5 files changed, 19 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/include/asm/xen/xen-ops.h
 create mode 100644 arch/arm64/include/asm/xen/xen-ops.h
 create mode 100644 include/xen/arm/xen-ops.h

diff --git a/arch/arm/include/asm/xen/xen-ops.h b/arch/arm/include/asm/xen/xen-ops.h
new file mode 100644
index 00000000..8d2fa24
--- /dev/null
+++ b/arch/arm/include/asm/xen/xen-ops.h
@@ -0,0 +1 @@
+#include <xen/arm/xen-ops.h>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 82ffac6..a1bf9dd 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -33,7 +33,7 @@
 #include <asm/dma-iommu.h>
 #include <asm/mach/map.h>
 #include <asm/system_info.h>
-#include <xen/swiotlb-xen.h>
+#include <asm/xen/xen-ops.h>
 
 #include "dma.h"
 #include "mm.h"
@@ -2288,8 +2288,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 	set_dma_ops(dev, dma_ops);
 
 #ifdef CONFIG_XEN
-	if (xen_initial_domain())
-		dev->dma_ops = &xen_swiotlb_dma_ops;
+	xen_setup_dma_ops(dev);
 #endif
 	dev->archdata.dma_ops_setup = true;
 }
diff --git a/arch/arm64/include/asm/xen/xen-ops.h b/arch/arm64/include/asm/xen/xen-ops.h
new file mode 100644
index 00000000..8d2fa24
--- /dev/null
+++ b/arch/arm64/include/asm/xen/xen-ops.h
@@ -0,0 +1 @@
+#include <xen/arm/xen-ops.h>
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 6719f9e..831e673 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -9,9 +9,9 @@
 #include <linux/dma-map-ops.h>
 #include <linux/dma-iommu.h>
 #include <xen/xen.h>
-#include <xen/swiotlb-xen.h>
 
 #include <asm/cacheflush.h>
+#include <asm/xen/xen-ops.h>
 
 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
 		enum dma_data_direction dir)
@@ -53,7 +53,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 		iommu_setup_dma_ops(dev, dma_base, dma_base + size - 1);
 
 #ifdef CONFIG_XEN
-	if (xen_swiotlb_detect())
-		dev->dma_ops = &xen_swiotlb_dma_ops;
+	xen_setup_dma_ops(dev);
 #endif
 }
diff --git a/include/xen/arm/xen-ops.h b/include/xen/arm/xen-ops.h
new file mode 100644
index 00000000..621da05
--- /dev/null
+++ b/include/xen/arm/xen-ops.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM_XEN_OPS_H
+#define _ASM_ARM_XEN_OPS_H
+
+#include <xen/swiotlb-xen.h>
+
+static inline void xen_setup_dma_ops(struct device *dev)
+{
+	if (xen_swiotlb_detect())
+		dev->dma_ops = &xen_swiotlb_dma_ops;
+}
+
+#endif /* _ASM_ARM_XEN_OPS_H */
-- 
2.7.4