linux/drivers/acpi/arm64/dma.c
Robin Murphy fece6530bf dma-mapping: Add helpers for dma_range_map bounds
Several places want to compute the lower and/or upper bounds of a
dma_range_map, so let's factor that out into reusable helpers.

Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com> # For arm64
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/45ec52f033ec4dfb364e23f48abaf787f612fa53.1713523152.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-04-26 12:07:24 +02:00

48 lines
1.2 KiB
C

// 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;
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)
end = dev->coherent_dma_mask;
else
end = (1ULL << 32) - 1;
ret = acpi_dma_get_range(dev, &map);
if (!ret && map) {
end = dma_range_map_max(map);
dev->dma_range_map = map;
}
if (ret == -ENODEV)
ret = iort_dma_get_ranges(dev, &end);
if (!ret) {
/*
* Limit coherent and dma mask based on size retrieved from
* firmware.
*/
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);
}
}