// SPDX-License-Identifier: GPL-2.0
/*
 * Dummy DMA ops that always fail.
 */
#include <linux/dma-map-ops.h>

static int dma_dummy_mmap(struct device *dev, struct vm_area_struct *vma,
                void *cpu_addr, dma_addr_t dma_addr, size_t size,
                unsigned long attrs)
{
        return -ENXIO;
}

static dma_addr_t dma_dummy_map_phys(struct device *dev, phys_addr_t phys,
                size_t size, enum dma_data_direction dir, unsigned long attrs)
{
        return DMA_MAPPING_ERROR;
}
static void dma_dummy_unmap_phys(struct device *dev, dma_addr_t dma_handle,
                size_t size, enum dma_data_direction dir, unsigned long attrs)
{
        /*
         * Dummy ops doesn't support map_phys, so unmap_page should never be
         * called.
         */
        WARN_ON_ONCE(true);
}

static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl,
                int nelems, enum dma_data_direction dir,
                unsigned long attrs)
{
        return -EINVAL;
}

static void dma_dummy_unmap_sg(struct device *dev, struct scatterlist *sgl,
                int nelems, enum dma_data_direction dir,
                unsigned long attrs)
{
        /*
         * Dummy ops doesn't support map_sg, so unmap_sg should never be called.
         */
        WARN_ON_ONCE(true);
}

static int dma_dummy_supported(struct device *hwdev, u64 mask)
{
        return 0;
}

const struct dma_map_ops dma_dummy_ops = {
        .mmap                   = dma_dummy_mmap,
        .map_phys               = dma_dummy_map_phys,
        .unmap_phys             = dma_dummy_unmap_phys,
        .map_sg                 = dma_dummy_map_sg,
        .unmap_sg               = dma_dummy_unmap_sg,
        .dma_supported          = dma_dummy_supported,
};