1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * Copyright (c) 2014 The Chromium OS Authors
8 #include <linux/shmem_fs.h>
9 #include <linux/dma-buf.h>
11 #include <drm/drm_prime.h>
15 struct udl_drm_dmabuf_attachment {
17 enum dma_data_direction dir;
21 static int udl_attach_dma_buf(struct dma_buf *dmabuf,
22 struct dma_buf_attachment *attach)
24 struct udl_drm_dmabuf_attachment *udl_attach;
26 DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
27 attach->dmabuf->size);
29 udl_attach = kzalloc(sizeof(*udl_attach), GFP_KERNEL);
33 udl_attach->dir = DMA_NONE;
34 attach->priv = udl_attach;
39 static void udl_detach_dma_buf(struct dma_buf *dmabuf,
40 struct dma_buf_attachment *attach)
42 struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
48 DRM_DEBUG_PRIME("[DEV:%s] size:%zd\n", dev_name(attach->dev),
49 attach->dmabuf->size);
51 sgt = &udl_attach->sgt;
53 if (udl_attach->dir != DMA_NONE)
54 dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
62 static struct sg_table *udl_map_dma_buf(struct dma_buf_attachment *attach,
63 enum dma_data_direction dir)
65 struct udl_drm_dmabuf_attachment *udl_attach = attach->priv;
66 struct udl_gem_object *obj = to_udl_bo(attach->dmabuf->priv);
67 struct drm_device *dev = obj->base.dev;
68 struct udl_device *udl = dev->dev_private;
69 struct scatterlist *rd, *wr;
70 struct sg_table *sgt = NULL;
75 DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir=%d\n", dev_name(attach->dev),
76 attach->dmabuf->size, dir);
78 /* just return current sgt if already requested. */
79 if (udl_attach->dir == dir && udl_attach->is_mapped)
80 return &udl_attach->sgt;
83 ret = udl_gem_get_pages(obj);
85 DRM_ERROR("failed to map pages.\n");
90 page_count = obj->base.size / PAGE_SIZE;
91 obj->sg = drm_prime_pages_to_sg(obj->pages, page_count);
92 if (IS_ERR(obj->sg)) {
93 DRM_ERROR("failed to allocate sgt.\n");
94 return ERR_CAST(obj->sg);
97 sgt = &udl_attach->sgt;
99 ret = sg_alloc_table(sgt, obj->sg->orig_nents, GFP_KERNEL);
101 DRM_ERROR("failed to alloc sgt.\n");
102 return ERR_PTR(-ENOMEM);
105 mutex_lock(&udl->gem_lock);
109 for (i = 0; i < sgt->orig_nents; ++i) {
110 sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
115 if (dir != DMA_NONE) {
116 nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
118 DRM_ERROR("failed to map sgl with iommu.\n");
125 udl_attach->is_mapped = true;
126 udl_attach->dir = dir;
127 attach->priv = udl_attach;
130 mutex_unlock(&udl->gem_lock);
134 static void udl_unmap_dma_buf(struct dma_buf_attachment *attach,
135 struct sg_table *sgt,
136 enum dma_data_direction dir)
139 DRM_DEBUG_PRIME("[DEV:%s] size:%zd dir:%d\n", dev_name(attach->dev),
140 attach->dmabuf->size, dir);
143 static void *udl_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
150 static void udl_dmabuf_kunmap(struct dma_buf *dma_buf,
151 unsigned long page_num, void *addr)
156 static int udl_dmabuf_mmap(struct dma_buf *dma_buf,
157 struct vm_area_struct *vma)
164 static const struct dma_buf_ops udl_dmabuf_ops = {
165 .attach = udl_attach_dma_buf,
166 .detach = udl_detach_dma_buf,
167 .map_dma_buf = udl_map_dma_buf,
168 .unmap_dma_buf = udl_unmap_dma_buf,
169 .map = udl_dmabuf_kmap,
170 .unmap = udl_dmabuf_kunmap,
171 .mmap = udl_dmabuf_mmap,
172 .release = drm_gem_dmabuf_release,
175 struct dma_buf *udl_gem_prime_export(struct drm_gem_object *obj, int flags)
177 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
179 exp_info.ops = &udl_dmabuf_ops;
180 exp_info.size = obj->size;
181 exp_info.flags = flags;
184 return drm_gem_dmabuf_export(obj->dev, &exp_info);
187 static int udl_prime_create(struct drm_device *dev,
190 struct udl_gem_object **obj_p)
192 struct udl_gem_object *obj;
195 npages = size / PAGE_SIZE;
198 obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
203 obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
204 if (obj->pages == NULL) {
205 DRM_ERROR("obj pages is NULL %d\n", npages);
209 drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
215 struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
216 struct dma_buf *dma_buf)
218 struct dma_buf_attachment *attach;
220 struct udl_gem_object *uobj;
224 get_device(dev->dev);
225 attach = dma_buf_attach(dma_buf, dev->dev);
226 if (IS_ERR(attach)) {
227 put_device(dev->dev);
228 return ERR_CAST(attach);
231 get_dma_buf(dma_buf);
233 sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
239 ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
243 uobj->base.import_attach = attach;
248 dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
250 dma_buf_detach(dma_buf, attach);
251 dma_buf_put(dma_buf);
252 put_device(dev->dev);