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

   1 /*
   2  * Copyright © 2016 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  */
  24
  25 #include "mock_dmabuf.h"
  26
  27 static struct sg_table *mock_map_dma_buf(struct dma_buf_attachment *attachment,
  28                                          enum dma_data_direction dir)
  29 {
  30         struct mock_dmabuf *mock = to_mock(attachment->dmabuf);
  31         struct sg_table *st;
  32         struct scatterlist *sg;
  33         int i, err;
  34
  35         st = kmalloc(sizeof(*st), GFP_KERNEL);
  36         if (!st)
  37                 return ERR_PTR(-ENOMEM);
  38
  39         err = sg_alloc_table(st, mock->npages, GFP_KERNEL);
  40         if (err)
  41                 goto err_free;
  42
  43         sg = st->sgl;
  44         for (i = 0; i < mock->npages; i++) {
  45                 sg_set_page(sg, mock->pages[i], PAGE_SIZE, 0);
  46                 sg = sg_next(sg);
  47         }
  48
  49         if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
  50                 err = -ENOMEM;
  51                 goto err_st;
  52         }
  53
  54         return st;
  55
  56 err_st:
  57         sg_free_table(st);
  58 err_free:
  59         kfree(st);
  60         return ERR_PTR(err);
  61 }
  62
  63 static void mock_unmap_dma_buf(struct dma_buf_attachment *attachment,
  64                                struct sg_table *st,
  65                                enum dma_data_direction dir)
  66 {
  67         dma_unmap_sg(attachment->dev, st->sgl, st->nents, dir);
  68         sg_free_table(st);
  69         kfree(st);
  70 }
  71
  72 static void mock_dmabuf_release(struct dma_buf *dma_buf)
  73 {
  74         struct mock_dmabuf *mock = to_mock(dma_buf);
  75         int i;
  76
  77         for (i = 0; i < mock->npages; i++)
  78                 put_page(mock->pages[i]);
  79
  80         kfree(mock);
  81 }
  82
  83 static void *mock_dmabuf_vmap(struct dma_buf *dma_buf)
  84 {
  85         struct mock_dmabuf *mock = to_mock(dma_buf);
  86
  87         return vm_map_ram(mock->pages, mock->npages, 0, PAGE_KERNEL);
  88 }
  89
  90 static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
  91 {
  92         struct mock_dmabuf *mock = to_mock(dma_buf);
  93
  94         vm_unmap_ram(vaddr, mock->npages);
  95 }
  96
  97 static void *mock_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
  98 {
  99         struct mock_dmabuf *mock = to_mock(dma_buf);
 100
 101         return kmap_atomic(mock->pages[page_num]);
 102 }
 103
 104 static void mock_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 105 {
 106         kunmap_atomic(addr);
 107 }
 108
 109 static void *mock_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 110 {
 111         struct mock_dmabuf *mock = to_mock(dma_buf);
 112
 113         return kmap(mock->pages[page_num]);
 114 }
 115
 116 static void mock_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
 117 {
 118         struct mock_dmabuf *mock = to_mock(dma_buf);
 119
 120         return kunmap(mock->pages[page_num]);
 121 }
 122
 123 static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 124 {
 125         return -ENODEV;
 126 }
 127
 128 static const struct dma_buf_ops mock_dmabuf_ops =  {
 129         .map_dma_buf = mock_map_dma_buf,
 130         .unmap_dma_buf = mock_unmap_dma_buf,
 131         .release = mock_dmabuf_release,
 132         .map = mock_dmabuf_kmap,
 133         .map_atomic = mock_dmabuf_kmap_atomic,
 134         .unmap = mock_dmabuf_kunmap,
 135         .unmap_atomic = mock_dmabuf_kunmap_atomic,
 136         .mmap = mock_dmabuf_mmap,
 137         .vmap = mock_dmabuf_vmap,
 138         .vunmap = mock_dmabuf_vunmap,
 139 };
 140
 141 static struct dma_buf *mock_dmabuf(int npages)
 142 {
 143         struct mock_dmabuf *mock;
 144         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 145         struct dma_buf *dmabuf;
 146         int i;
 147
 148         mock = kmalloc(sizeof(*mock) + npages * sizeof(struct page *),
 149                        GFP_KERNEL);
 150         if (!mock)
 151                 return ERR_PTR(-ENOMEM);
 152
 153         mock->npages = npages;
 154         for (i = 0; i < npages; i++) {
 155                 mock->pages[i] = alloc_page(GFP_KERNEL);
 156                 if (!mock->pages[i])
 157                         goto err;
 158         }
 159
 160         exp_info.ops = &mock_dmabuf_ops;
 161         exp_info.size = npages * PAGE_SIZE;
 162         exp_info.flags = O_CLOEXEC;
 163         exp_info.priv = mock;
 164
 165         dmabuf = dma_buf_export(&exp_info);
 166         if (IS_ERR(dmabuf))
 167                 goto err;
 168
 169         return dmabuf;
 170
 171 err:
 172         while (i--)
 173                 put_page(mock->pages[i]);
 174         kfree(mock);
 175         return ERR_PTR(-ENOMEM);
 176 }