dma-mapping: remove <asm/dma-contiguous.h>

Just provide a weak default definition of dma_contiguous_early_fixup and
let arm override it.

Signed-off-by: Christoph Hellwig <hch@lst.de>

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

@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ASMARM_DMA_CONTIGUOUS_H
-#define ASMARM_DMA_CONTIGUOUS_H
-
-#ifdef __KERNEL__
-#ifdef CONFIG_DMA_CMA
-
-#include <linux/types.h>
-
-void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size);
-
-#endif
-#endif
-
-#endif

arch/arm/mm/dma-mapping.c

@@ -34,7 +34,6 @@
 #include <asm/dma-iommu.h>
 #include <asm/mach/map.h>
 #include <asm/system_info.h>
-#include <asm/dma-contiguous.h>
 #include <xen/swiotlb-xen.h>
 
 #include "dma.h"

include/asm-generic/Kbuild

@@ -16,7 +16,6 @@ mandatory-y += current.h
 mandatory-y += delay.h
 mandatory-y += device.h
 mandatory-y += div64.h
-mandatory-y += dma-contiguous.h
 mandatory-y += dma-mapping.h
 mandatory-y += dma.h
 mandatory-y += emergency-restart.h

include/asm-generic/dma-contiguous.h

@@ -1,10 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_GENERIC_DMA_CONTIGUOUS_H
-#define _ASM_GENERIC_DMA_CONTIGUOUS_H
-
-#include <linux/types.h>
-
-static inline void
-dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { }
-
-#endif

include/linux/dma-map-ops.h

@@ -116,6 +116,8 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
 				 int count);
 struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp);
 void dma_free_contiguous(struct device *dev, struct page *page, size_t size);
+
+void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size);
 #else /* CONFIG_DMA_CMA */
 static inline struct cma *dev_get_cma_area(struct device *dev)
 {

kernel/dma/contiguous.c

@@ -44,7 +44,6 @@
 #endif
 
 #include <asm/page.h>
-#include <asm/dma-contiguous.h>
 
 #include <linux/memblock.h>
 #include <linux/err.h>
@@ -212,6 +211,11 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
 	}
 }
 
+void __weak
+dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
+{
+}
+
 /**
  * dma_contiguous_reserve_area() - reserve custom contiguous area
  * @size: Size of the reserved area (in bytes),