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, u64 *dma_addr, u64 *dma_size) 8 { 9 int ret; 10 u64 end, mask; 11 u64 dmaaddr = 0, size = 0, offset = 0; 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 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 26 else 27 size = 1ULL << 32; 28 29 ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size); 30 if (ret == -ENODEV) 31 ret = iort_dma_get_ranges(dev, &size); 32 if (!ret) { 33 /* 34 * Limit coherent and dma mask based on size retrieved from 35 * firmware. 36 */ 37 end = dmaaddr + size - 1; 38 mask = DMA_BIT_MASK(ilog2(end) + 1); 39 dev->bus_dma_limit = end; 40 dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); 41 *dev->dma_mask = min(*dev->dma_mask, mask); 42 } 43 44 *dma_addr = dmaaddr; 45 *dma_size = size; 46 47 ret = dma_direct_set_offset(dev, dmaaddr + offset, dmaaddr, size); 48 49 dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : ""); 50 } 51