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