> +#ifndef ASM_ARC_DMA_MAPPING_H
> +#define ASM_ARC_DMA_MAPPING_H
> +
> +#define arch_setup_dma_ops arch_setup_dma_ops
> +
> +#include <asm-generic/dma-mapping.h>
> +
> +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
> + const struct iommu_ops *iommu, bool coherent);
Can you keep the #define for arch_setup_dma_ops right next to the
prototype?
> index 000000000000..9d0d310bbf5a
> --- /dev/null
> +++ b/arch/arc/mm/dma-mapping.c
> @@ -0,0 +1,20 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// (C) 2018 Synopsys, Inc. (www.synopsys.com)
> +
> +#include <linux/dma-mapping.h>
> +
> +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
> + const struct iommu_ops *iommu, bool coherent)
> +{
> + const struct dma_map_ops *dma_ops = &dma_noncoherent_ops;
> +
> + /*
> + * IOC hardware snoops all DMA traffic keeping the caches consistent
> + * with memory - eliding need for any explicit cache maintenance of
> + * DMA buffers - so we can use dma_direct cache ops.
> + */
> + if (is_isa_arcv2() && ioc_enable && coherent)
> + dma_ops = &dma_direct_ops;
> +
> + set_dma_ops(dev, dma_ops);
> +}
Why not just write the routines as:
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct iommu_ops *iommu, bool coherent)
{
if (is_isa_arcv2() && ioc_enable && coherent)
set_dma_ops(dev, &dma_direct_ops);
else
set_dma_ops(dev, &dma_noncoherent_ops);
}
Also a new file just for this routine seems a little wasteful. Can't
you just squeeze it into setup.c or some other file?
