1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/acpi.h> 3 #include <linux/acpi_iort.h> 4 #include <linux/device.h> 5 #include <linux/dma-direct.h> 6 7 void 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 created 15 * it should have initialised its dma_mask pointer by this point. For 16 * now, we'll continue the legacy behaviour of coercing it to the 17 * 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 else 27 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 from 40 * 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