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1// SPDX-License-Identifier: GPL-2.0-only2#include <linux/acpi.h>3#include <linux/acpi_iort.h>4#include <linux/device.h>5#include <linux/dma-direct.h>6 7void acpi_arch_dma_setup(struct device *dev)8{9 int ret;10 u64 end, mask;11 const struct bus_dma_region *map = NULL;12 13 /*14 * If @dev is expected to be DMA-capable then the bus code that created15 * it should have initialised its dma_mask pointer by this point. For16 * now, we'll continue the legacy behaviour of coercing it to the17 * coherent mask if not, but we'll no longer do so quietly.18 */19 if (!dev->dma_mask) {20 dev_warn(dev, "DMA mask not set\n");21 dev->dma_mask = &dev->coherent_dma_mask;22 }23 24 if (dev->coherent_dma_mask)25 end = dev->coherent_dma_mask;26 else27 end = (1ULL << 32) - 1;28 29 ret = acpi_dma_get_range(dev, &map);30 if (!ret && map) {31 end = dma_range_map_max(map);32 dev->dma_range_map = map;33 }34 35 if (ret == -ENODEV)36 ret = iort_dma_get_ranges(dev, &end);37 if (!ret) {38 /*39 * Limit coherent and dma mask based on size retrieved from40 * firmware.41 */42 mask = DMA_BIT_MASK(ilog2(end) + 1);43 dev->bus_dma_limit = end;44 dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);45 *dev->dma_mask = min(*dev->dma_mask, mask);46 }47}48