// SPDX-License-Identifier: GPL-2.0-only #include <linux/acpi.h> #include <linux/acpi_iort.h> #include <linux/device.h> #include <linux/dma-direct.h> void acpi_arch_dma_setup(struct device *dev) { int ret; u64 end, mask; u64 size = 0; const struct bus_dma_region *map = NULL; /* * If @dev is expected to be DMA-capable then the bus code that created * it should have initialised its dma_mask pointer by this point. For * now, we'll continue the legacy behaviour of coercing it to the * coherent mask if not, but we'll no longer do so quietly. */ if (!dev->dma_mask) { dev_warn(dev, "DMA mask not set\n"); dev->dma_mask = &dev->coherent_dma_mask; } if (dev->coherent_dma_mask) size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); else size = 1ULL << 32; ret = acpi_dma_get_range(dev, &map); if (!ret && map) { const struct bus_dma_region *r = map; for (end = 0; r->size; r++) { if (r->dma_start + r->size - 1 > end) end = r->dma_start + r->size - 1; } size = end + 1; dev->dma_range_map = map; } if (ret == -ENODEV) ret = iort_dma_get_ranges(dev, &size); if (!ret) { /* * Limit coherent and dma mask based on size retrieved from * firmware. */ end = size - 1; mask = DMA_BIT_MASK(ilog2(end) + 1); dev->bus_dma_limit = end; dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask); *dev->dma_mask = min(*dev->dma_mask, mask); } }