mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 21:57:43 +00:00
c78c43fe7d
Use _DMA defined in ACPI spec for translation between
DMA address and CPU address, and implement acpi_arch_dma_setup
for initializing dev->dma_range_map, where acpi_dma_get_range
is called for parsing _DMA.
e.g.
If we have two dma ranges:
cpu address dma address size offset
0x200080000000 0x2080000000 0x400000000 0x1fe000000000
0x400080000000 0x4080000000 0x400000000 0x3fc000000000
_DMA for pci devices should be declared in host bridge as
flowing:
Name (_DMA, ResourceTemplate() {
QWordMemory (ResourceProducer,
PosDecode,
MinFixed,
MaxFixed,
NonCacheable,
ReadWrite,
0x0,
0x4080000000,
0x447fffffff,
0x3fc000000000,
0x400000000,
,
,
)
QWordMemory (ResourceProducer,
PosDecode,
MinFixed,
MaxFixed,
NonCacheable,
ReadWrite,
0x0,
0x2080000000,
0x247fffffff,
0x1fe000000000,
0x400000000,
,
,
)
})
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
30 lines
709 B
C
30 lines
709 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
|
|
*/
|
|
#include <linux/acpi.h>
|
|
#include <linux/dma-direct.h>
|
|
|
|
void acpi_arch_dma_setup(struct device *dev)
|
|
{
|
|
int ret;
|
|
u64 mask, end = 0;
|
|
const struct bus_dma_region *map = NULL;
|
|
|
|
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;
|
|
}
|
|
|
|
mask = DMA_BIT_MASK(ilog2(end) + 1);
|
|
dev->bus_dma_limit = end;
|
|
dev->dma_range_map = map;
|
|
dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);
|
|
*dev->dma_mask = min(*dev->dma_mask, mask);
|
|
}
|
|
|
|
}
|