linux_kernel/arch/ia64/kernel/dma-mapping.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/dma-mapping.h>
#include <linux/swiotlb.h>
#include <linux/export.h>

/* Set this to 1 if there is a HW IOMMU in the system */
int iommu_detected __read_mostly;

const struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);

#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)

static int __init dma_init(void)
{
	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);

	return 0;
}
fs_initcall(dma_init);

const struct dma_map_ops *dma_get_ops(struct device *dev)
{
	return dma_ops;
}
EXPORT_SYMBOL(dma_get_ops);

#ifdef CONFIG_SWIOTLB
void __init swiotlb_dma_init(void)
{
	dma_ops = &swiotlb_dma_ops;
	swiotlb_init(1);
}
#endif