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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>
31 lines
709 B
C
31 lines
709 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#include <linux/acpi.h>
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#include <linux/dma-direct.h>
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void acpi_arch_dma_setup(struct device *dev)
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{
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int ret;
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u64 mask, end = 0;
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const struct bus_dma_region *map = NULL;
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ret = acpi_dma_get_range(dev, &map);
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if (!ret && map) {
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const struct bus_dma_region *r = map;
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for (end = 0; r->size; r++) {
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if (r->dma_start + r->size - 1 > end)
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end = r->dma_start + r->size - 1;
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}
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mask = DMA_BIT_MASK(ilog2(end) + 1);
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dev->bus_dma_limit = end;
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dev->dma_range_map = map;
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dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);
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*dev->dma_mask = min(*dev->dma_mask, mask);
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}
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}
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