| 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: &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: &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 |