linux-zen-server/drivers/acpi/arm64/dma.c

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2023-08-30 17:53:23 +02:00
// 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);
}
}