Home | History | Annotate | Line # | Download | only in selftests 
      1 /*	$NetBSD: mock_dmabuf.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $	*/
      2 
      3 /*
      4  * SPDX-License-Identifier: MIT
      5  *
      6  * Copyright  2016 Intel Corporation
      7  */
      8 
      9 #include <sys/cdefs.h>
     10 __KERNEL_RCSID(0, "$NetBSD: mock_dmabuf.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $");
     11 
     12 #include "mock_dmabuf.h"
     13 
     14 static struct sg_table *mock_map_dma_buf(struct dma_buf_attachment *attachment,
     15 					 enum dma_data_direction dir)
     16 {
     17 	struct mock_dmabuf *mock = to_mock(attachment->dmabuf);
     18 	struct sg_table *st;
     19 	struct scatterlist *sg;
     20 	int i, err;
     21 
     22 	st = kmalloc(sizeof(*st), GFP_KERNEL);
     23 	if (!st)
     24 		return ERR_PTR(-ENOMEM);
     25 
     26 	err = sg_alloc_table(st, mock->npages, GFP_KERNEL);
     27 	if (err)
     28 		goto err_free;
     29 
     30 	sg = st->sgl;
     31 	for (i = 0; i < mock->npages; i++) {
     32 		sg_set_page(sg, mock->pages[i], PAGE_SIZE, 0);
     33 		sg = sg_next(sg);
     34 	}
     35 
     36 	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
     37 		err = -ENOMEM;
     38 		goto err_st;
     39 	}
     40 
     41 	return st;
     42 
     43 err_st:
     44 	sg_free_table(st);
     45 err_free:
     46 	kfree(st);
     47 	return ERR_PTR(err);
     48 }
     49 
     50 static void mock_unmap_dma_buf(struct dma_buf_attachment *attachment,
     51 			       struct sg_table *st,
     52 			       enum dma_data_direction dir)
     53 {
     54 	dma_unmap_sg(attachment->dev, st->sgl, st->nents, dir);
     55 	sg_free_table(st);
     56 	kfree(st);
     57 }
     58 
     59 static void mock_dmabuf_release(struct dma_buf *dma_buf)
     60 {
     61 	struct mock_dmabuf *mock = to_mock(dma_buf);
     62 	int i;
     63 
     64 	for (i = 0; i < mock->npages; i++)
     65 		put_page(mock->pages[i]);
     66 
     67 	kfree(mock);
     68 }
     69 
     70 static void *mock_dmabuf_vmap(struct dma_buf *dma_buf)
     71 {
     72 	struct mock_dmabuf *mock = to_mock(dma_buf);
     73 
     74 	return vm_map_ram(mock->pages, mock->npages, 0, PAGE_KERNEL);
     75 }
     76 
     77 static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
     78 {
     79 	struct mock_dmabuf *mock = to_mock(dma_buf);
     80 
     81 	vm_unmap_ram(vaddr, mock->npages);
     82 }
     83 
     84 static int mock_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
     85 {
     86 	return -ENODEV;
     87 }
     88 
     89 static 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 
     98 static 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 
    128 err:
    129 	while (i--)
    130 		put_page(mock->pages[i]);
    131 	kfree(mock);
    132 	return ERR_PTR(-ENOMEM);
    133 }
    134