1/*
  2 * SPDX-License-Identifier: MIT
  3 *
  4 * Copyright © 2016 Intel Corporation
  5 */
  6
  7#include "mock_dmabuf.h"
  8
  9static 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
 37err_st:
 38	sg_free_table(st);
 39err_free:
 40	kfree(st);
 41	return ERR_PTR(err);
 42}
 43
 44static 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
 53static 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
 64static int mock_dmabuf_vmap(struct dma_buf *dma_buf, struct iosys_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	iosys_map_set_vaddr(map, vaddr);
 73
 74	return 0;
 75}
 76
 77static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, struct iosys_map *map)
 78{
 79	struct mock_dmabuf *mock = to_mock(dma_buf);
 80
 81	vm_unmap_ram(map->vaddr, mock->npages);
 82}
 83
 84static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 85{
 86	return -ENODEV;
 87}
 88
 89static 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
 98static 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
128err:
129	while (i--)
130		put_page(mock->pages[i]);
131	kfree(mock);
132	return ERR_PTR(-ENOMEM);
133}