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
acpi_arch_dma_setup(struct device * dev,u64 * dma_addr,u64 * dma_size)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