linux/drivers/acpi/arm64/dma.c
Jianmin Lv bf2ee8d0c3 ACPI: scan: Support multiple DMA windows with different offsets
In DT systems configurations, of_dma_get_range() returns struct
bus_dma_region DMA regions; they are used to set-up devices
DMA windows with different offset available for translation between DMA
address and CPU address.

In ACPI systems configuration, acpi_dma_get_range() does not return
DMA regions yet and that precludes setting up the dev->dma_range_map
pointer and therefore DMA regions with multiple offsets.

Update acpi_dma_get_range() to return struct bus_dma_region
DMA regions like of_dma_get_range() does.

After updating acpi_dma_get_range(), acpi_arch_dma_setup() is changed for
ARM64, where the original dma_addr and size are removed as these
arguments are now redundant, and pass 0 and U64_MAX for dma_base
and size of arch_setup_dma_ops; this is a simplification consistent
with what other ACPI architectures also pass to iommu_setup_dma_ops().

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Reviewed-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-09-24 18:39:21 +02:00

57 lines
1.4 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;
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);
}
}