diff options
Diffstat (limited to 'arch/mips/loongson64/loongson-3/dma.c')
-rw-r--r-- | arch/mips/loongson64/loongson-3/dma.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/mips/loongson64/loongson-3/dma.c b/arch/mips/loongson64/loongson-3/dma.c new file mode 100644 index 000000000000..5e86635f71db --- /dev/null +++ b/arch/mips/loongson64/loongson-3/dma.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/dma-direct.h> +#include <linux/init.h> +#include <linux/swiotlb.h> + +dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) +{ + /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from + * Loongson-3's 48bit address space and embed it into 40bit */ + long nid = (paddr >> 44) & 0x3; + return ((nid << 44) ^ paddr) | (nid << 37); +} + +phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr) +{ + /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from + * Loongson-3's 48bit address space and embed it into 40bit */ + long nid = (daddr >> 37) & 0x3; + return ((nid << 37) ^ daddr) | (nid << 44); +} + +void __init plat_swiotlb_setup(void) +{ + swiotlb_init(1); +} |