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-rw-r--r--arch/loongarch/kernel/dma.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/dma.c b/arch/loongarch/kernel/dma.c
new file mode 100644
index 0000000000..7a9c6a9dd2
--- /dev/null
+++ b/arch/loongarch/kernel/dma.c
@@ -0,0 +1,30 @@
+// 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);
+ }
+
+}