1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2016 Intel Corporation 5 */ 6 7 #include "mock_dmabuf.h" 8 9 static struct sg_table *mock_map_dma_buf(struct dma_buf_attachment *attachment, 10 enum dma_data_direction dir) 11 { 12 struct mock_dmabuf *mock = to_mock(attachment->dmabuf); 13 struct sg_table *st; 14 struct scatterlist *sg; 15 int i, err; 16 17 st = kmalloc(sizeof(*st), GFP_KERNEL); 18 if (!st) 19 return ERR_PTR(-ENOMEM); 20 21 err = sg_alloc_table(st, mock->npages, GFP_KERNEL); 22 if (err) 23 goto err_free; 24 25 sg = st->sgl; 26 for (i = 0; i < mock->npages; i++) { 27 sg_set_page(sg, mock->pages[i], PAGE_SIZE, 0); 28 sg = sg_next(sg); 29 } 30 31 err = dma_map_sgtable(attachment->dev, st, dir, 0); 32 if (err) 33 goto err_st; 34 35 return st; 36 37 err_st: 38 sg_free_table(st); 39 err_free: 40 kfree(st); 41 return ERR_PTR(err); 42 } 43 44 static void mock_unmap_dma_buf(struct dma_buf_attachment *attachment, 45 struct sg_table *st, 46 enum dma_data_direction dir) 47 { 48 dma_unmap_sgtable(attachment->dev, st, dir, 0); 49 sg_free_table(st); 50 kfree(st); 51 } 52 53 static void mock_dmabuf_release(struct dma_buf *dma_buf) 54 { 55 struct mock_dmabuf *mock = to_mock(dma_buf); 56 int i; 57 58 for (i = 0; i < mock->npages; i++) 59 put_page(mock->pages[i]); 60 61 kfree(mock); 62 } 63 64 static int mock_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map) 65 { 66 struct mock_dmabuf *mock = to_mock(dma_buf); 67 void *vaddr; 68 69 vaddr = vm_map_ram(mock->pages, mock->npages, 0); 70 if (!vaddr) 71 return -ENOMEM; 72 dma_buf_map_set_vaddr(map, vaddr); 73 74 return 0; 75 } 76 77 static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map) 78 { 79 struct mock_dmabuf *mock = to_mock(dma_buf); 80 81 vm_unmap_ram(map->vaddr, mock->npages); 82 } 83 84 static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) 85 { 86 return -ENODEV; 87 } 88 89 static const struct dma_buf_ops mock_dmabuf_ops = { 90 .map_dma_buf = mock_map_dma_buf, 91 .unmap_dma_buf = mock_unmap_dma_buf, 92 .release = mock_dmabuf_release, 93 .mmap = mock_dmabuf_mmap, 94 .vmap = mock_dmabuf_vmap, 95 .vunmap = mock_dmabuf_vunmap, 96 }; 97 98 static struct dma_buf *mock_dmabuf(int npages) 99 { 100 struct mock_dmabuf *mock; 101 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 102 struct dma_buf *dmabuf; 103 int i; 104 105 mock = kmalloc(sizeof(*mock) + npages * sizeof(struct page *), 106 GFP_KERNEL); 107 if (!mock) 108 return ERR_PTR(-ENOMEM); 109 110 mock->npages = npages; 111 for (i = 0; i < npages; i++) { 112 mock->pages[i] = alloc_page(GFP_KERNEL); 113 if (!mock->pages[i]) 114 goto err; 115 } 116 117 exp_info.ops = &mock_dmabuf_ops; 118 exp_info.size = npages * PAGE_SIZE; 119 exp_info.flags = O_CLOEXEC; 120 exp_info.priv = mock; 121 122 dmabuf = dma_buf_export(&exp_info); 123 if (IS_ERR(dmabuf)) 124 goto err; 125 126 return dmabuf; 127 128 err: 129 while (i--) 130 put_page(mock->pages[i]); 131 kfree(mock); 132 return ERR_PTR(-ENOMEM); 133 } 134