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 if (dev->dma_range_map) { 30 dev_dbg(dev, "dma_range_map already set\n"); 31 return; 32 } 33 34 ret = acpi_dma_get_range(dev, &map); 35 if (!ret && map) { 36 end = dma_range_map_max(map); 37 dev->dma_range_map = map; 38 } 39 40 if (ret == -ENODEV) 41 ret = iort_dma_get_ranges(dev, &end); 42 if (!ret) { 43 /* 44 * Limit coherent and dma mask based on size retrieved from 45 * firmware. 46 */ 47 mask = DMA_BIT_MASK(ilog2(end) + 1); 48 dev->bus_dma_limit = end; 49 dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); 50 *dev->dma_mask = min(*dev->dma_mask, mask); 51 } 52 } 53