57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/acpi.h>
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#include <linux/acpi_iort.h>
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#include <linux/device.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 end, mask;
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u64 size = 0;
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const struct bus_dma_region *map = NULL;
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/*
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* If @dev is expected to be DMA-capable then the bus code that created
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* it should have initialised its dma_mask pointer by this point. For
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* now, we'll continue the legacy behaviour of coercing it to the
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* coherent mask if not, but we'll no longer do so quietly.
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*/
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if (!dev->dma_mask) {
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dev_warn(dev, "DMA mask not set\n");
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dev->dma_mask = &dev->coherent_dma_mask;
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}
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if (dev->coherent_dma_mask)
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size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
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else
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size = 1ULL << 32;
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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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size = end + 1;
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dev->dma_range_map = map;
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}
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if (ret == -ENODEV)
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ret = iort_dma_get_ranges(dev, &size);
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if (!ret) {
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/*
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* Limit coherent and dma mask based on size retrieved from
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* firmware.
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*/
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end = size - 1;
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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->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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