diff options
Diffstat (limited to 'drivers/acpi/arm64/dma.c')
| -rw-r--r-- | drivers/acpi/arm64/dma.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/drivers/acpi/arm64/dma.c b/drivers/acpi/arm64/dma.c new file mode 100644 index 000000000000..f16739ad3cc0 --- /dev/null +++ b/drivers/acpi/arm64/dma.c @@ -0,0 +1,50 @@ +// 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, u64 *dma_addr, u64 *dma_size) +{ + int ret; + u64 end, mask; + u64 dmaaddr = 0, size = 0, offset = 0; + + /* + * 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, &dmaaddr, &offset, &size); + if (ret == -ENODEV) + ret = iort_dma_get_ranges(dev, &size); + if (!ret) { + /* + * Limit coherent and dma mask based on size retrieved from + * firmware. + */ + end = dmaaddr + 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); + } + + *dma_addr = dmaaddr; + *dma_size = size; + + ret = dma_direct_set_offset(dev, dmaaddr + offset, dmaaddr, size); + + dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : ""); +} |