// SPDX-License-Identifier: GPL-2.0-only
#include <linux/acpi.h>
#include <linux/acpi_iort.h>
#include <linux/device.h>
#include <linux/dma-direct.h>

void acpi_arch_dma_setup(struct device *dev)
{
        int ret;
        u64 end, mask;
        const struct bus_dma_region *map = NULL;

        /*
         * If @dev is expected to be DMA-capable then the bus code that created
         * it should have initialised its dma_mask pointer by this point. For
         * now, we'll continue the legacy behaviour of coercing it to the
         * coherent mask if not, but we'll no longer do so quietly.
         */
        if (!dev->dma_mask) {
                dev_warn(dev, "DMA mask not set\n");
                dev->dma_mask = &dev->coherent_dma_mask;
        }

        if (dev->coherent_dma_mask)
                end = dev->coherent_dma_mask;
        else
                end = (1ULL << 32) - 1;

        if (dev->dma_range_map) {
                dev_dbg(dev, "dma_range_map already set\n");
                return;
        }

        ret = acpi_dma_get_range(dev, &map);
        if (!ret && map) {
                end = dma_range_map_max(map);
                dev->dma_range_map = map;
        }

        if (ret == -ENODEV)
                ret = iort_dma_get_ranges(dev, &end);
        if (!ret) {
                /*
                 * Limit coherent and dma mask based on size retrieved from
                 * firmware.
                 */
                mask = DMA_BIT_MASK(ilog2(end) + 1);
                dev->bus_dma_limit = end;
                dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);
                *dev->dma_mask = min(*dev->dma_mask, mask);
        }
}