1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Dummy DMA ops that always fail. 4 */ 5 #include <linux/dma-map-ops.h> 6 7 static int dma_dummy_mmap(struct device *dev, struct vm_area_struct *vma, 8 void *cpu_addr, dma_addr_t dma_addr, size_t size, 9 unsigned long attrs) 10 { 11 return -ENXIO; 12 } 13 14 static dma_addr_t dma_dummy_map_page(struct device *dev, struct page *page, 15 unsigned long offset, size_t size, enum dma_data_direction dir, 16 unsigned long attrs) 17 { 18 return DMA_MAPPING_ERROR; 19 } 20 21 static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl, 22 int nelems, enum dma_data_direction dir, 23 unsigned long attrs) 24 { 25 return 0; 26 } 27 28 static int dma_dummy_supported(struct device *hwdev, u64 mask) 29 { 30 return 0; 31 } 32 33 const struct dma_map_ops dma_dummy_ops = { 34 .mmap = dma_dummy_mmap, 35 .map_page = dma_dummy_map_page, 36 .map_sg = dma_dummy_map_sg, 37 .dma_supported = dma_dummy_supported, 38 }; 39