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
 10static 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
 38err_st:
 39	sg_free_table(st);
 40err_free:
 41	kfree(st);
 42	return ERR_PTR(err);
 43}
 44
 45static 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
 54static 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
 65static 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
 78static 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
 85static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 86{
 87	return -ENODEV;
 88}
 89
 90static 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
 99static 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(sizeof(*mock) + npages * sizeof(struct page *),
107		       GFP_KERNEL);
108	if (!mock)
109		return ERR_PTR(-ENOMEM);
110
111	mock->npages = npages;
112	for (i = 0; i < npages; i++) {
113		mock->pages[i] = alloc_page(GFP_KERNEL);
114		if (!mock->pages[i])
115			goto err;
116	}
117
118	exp_info.ops = &mock_dmabuf_ops;
119	exp_info.size = npages * PAGE_SIZE;
120	exp_info.flags = O_CLOEXEC;
121	exp_info.priv = mock;
122
123	dmabuf = dma_buf_export(&exp_info);
124	if (IS_ERR(dmabuf))
125		goto err;
126
127	return dmabuf;
128
129err:
130	while (i--)
131		put_page(mock->pages[i]);
132	kfree(mock);
133	return ERR_PTR(-ENOMEM);
134}