drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c

   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         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  32                 err = -ENOMEM;
  33                 goto err_st;
  34         }
  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_sg(attachment->dev, st->sgl, st->nents, dir);
  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 void *mock_dmabuf_vmap(struct dma_buf *dma_buf)
  66 {
  67         struct mock_dmabuf *mock = to_mock(dma_buf);
  68
  69         return vm_map_ram(mock->pages, mock->npages, 0);
  70 }
  71
  72 static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
  73 {
  74         struct mock_dmabuf *mock = to_mock(dma_buf);
  75
  76         vm_unmap_ram(vaddr, mock->npages);
  77 }
  78
  79 static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
  80 {
  81         return -ENODEV;
  82 }
  83
  84 static const struct dma_buf_ops mock_dmabuf_ops =  {
  85         .map_dma_buf = mock_map_dma_buf,
  86         .unmap_dma_buf = mock_unmap_dma_buf,
  87         .release = mock_dmabuf_release,
  88         .mmap = mock_dmabuf_mmap,
  89         .vmap = mock_dmabuf_vmap,
  90         .vunmap = mock_dmabuf_vunmap,
  91 };
  92
  93 static struct dma_buf *mock_dmabuf(int npages)
  94 {
  95         struct mock_dmabuf *mock;
  96         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
  97         struct dma_buf *dmabuf;
  98         int i;
  99
 100         mock = kmalloc(sizeof(*mock) + npages * sizeof(struct page *),
 101                        GFP_KERNEL);
 102         if (!mock)
 103                 return ERR_PTR(-ENOMEM);
 104
 105         mock->npages = npages;
 106         for (i = 0; i < npages; i++) {
 107                 mock->pages[i] = alloc_page(GFP_KERNEL);
 108                 if (!mock->pages[i])
 109                         goto err;
 110         }
 111
 112         exp_info.ops = &mock_dmabuf_ops;
 113         exp_info.size = npages * PAGE_SIZE;
 114         exp_info.flags = O_CLOEXEC;
 115         exp_info.priv = mock;
 116
 117         dmabuf = dma_buf_export(&exp_info);
 118         if (IS_ERR(dmabuf))
 119                 goto err;
 120
 121         return dmabuf;
 122
 123 err:
 124         while (i--)
 125                 put_page(mock->pages[i]);
 126         kfree(mock);
 127         return ERR_PTR(-ENOMEM);
 128 }