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 u64 size = 0; 12 const struct bus_dma_region *map = NULL; 13 14 /* 15 * If @dev is expected to be DMA-capable then the bus code that created 16 * it should have initialised its dma_mask pointer by this point. For 17 * now, we'll continue the legacy behaviour of coercing it to the 18 * coherent mask if not, but we'll no longer do so quietly. 19 */ 20 if (!dev->dma_mask) { 21 dev_warn(dev, "DMA mask not set\n"); 22 dev->dma_mask = &dev->coherent_dma_mask; 23 } 24 25 if (dev->coherent_dma_mask) 26 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 27 else 28 size = 1ULL << 32; 29 30 ret = acpi_dma_get_range(dev, &map); 31 if (!ret && map) { 32 const struct bus_dma_region *r = map; 33 34 for (end = 0; r->size; r++) { 35 if (r->dma_start + r->size - 1 > end) 36 end = r->dma_start + r->size - 1; 37 } 38 39 size = end + 1; 40 dev->dma_range_map = map; 41 } 42 43 if (ret == -ENODEV) 44 ret = iort_dma_get_ranges(dev, &size); 45 if (!ret) { 46 /* 47 * Limit coherent and dma mask based on size retrieved from 48 * firmware. 49 */ 50 end = size - 1; 51 mask = DMA_BIT_MASK(ilog2(end) + 1); 52 dev->bus_dma_limit = end; 53 dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); 54 *dev->dma_mask = min(*dev->dma_mask, mask); 55 } 56 } 57