1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2015 MediaTek Inc.
4 */
5
6 #include <linux/dma-buf.h>
7
8 #include <drm/drm.h>
9 #include <drm/drm_device.h>
10 #include <drm/drm_gem.h>
11 #include <drm/drm_prime.h>
12
13 #include "mtk_drm_drv.h"
14 #include "mtk_drm_gem.h"
15
mtk_drm_gem_init(struct drm_device * dev,unsigned long size)16 static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
17 unsigned long size)
18 {
19 struct mtk_drm_gem_obj *mtk_gem_obj;
20 int ret;
21
22 size = round_up(size, PAGE_SIZE);
23
24 mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
25 if (!mtk_gem_obj)
26 return ERR_PTR(-ENOMEM);
27
28 ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
29 if (ret < 0) {
30 DRM_ERROR("failed to initialize gem object\n");
31 kfree(mtk_gem_obj);
32 return ERR_PTR(ret);
33 }
34
35 return mtk_gem_obj;
36 }
37
mtk_drm_gem_create(struct drm_device * dev,size_t size,bool alloc_kmap)38 struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
39 size_t size, bool alloc_kmap)
40 {
41 struct mtk_drm_private *priv = dev->dev_private;
42 struct mtk_drm_gem_obj *mtk_gem;
43 struct drm_gem_object *obj;
44 int ret;
45
46 mtk_gem = mtk_drm_gem_init(dev, size);
47 if (IS_ERR(mtk_gem))
48 return ERR_CAST(mtk_gem);
49
50 obj = &mtk_gem->base;
51
52 mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
53
54 if (!alloc_kmap)
55 mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
56
57 mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
58 &mtk_gem->dma_addr, GFP_KERNEL,
59 mtk_gem->dma_attrs);
60 if (!mtk_gem->cookie) {
61 DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
62 ret = -ENOMEM;
63 goto err_gem_free;
64 }
65
66 if (alloc_kmap)
67 mtk_gem->kvaddr = mtk_gem->cookie;
68
69 DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
70 mtk_gem->cookie, &mtk_gem->dma_addr,
71 size);
72
73 return mtk_gem;
74
75 err_gem_free:
76 drm_gem_object_release(obj);
77 kfree(mtk_gem);
78 return ERR_PTR(ret);
79 }
80
mtk_drm_gem_free_object(struct drm_gem_object * obj)81 void mtk_drm_gem_free_object(struct drm_gem_object *obj)
82 {
83 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
84 struct mtk_drm_private *priv = obj->dev->dev_private;
85
86 if (mtk_gem->sg)
87 drm_prime_gem_destroy(obj, mtk_gem->sg);
88 else
89 dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
90 mtk_gem->dma_addr, mtk_gem->dma_attrs);
91
92 /* release file pointer to gem object. */
93 drm_gem_object_release(obj);
94
95 kfree(mtk_gem);
96 }
97
mtk_drm_gem_dumb_create(struct drm_file * file_priv,struct drm_device * dev,struct drm_mode_create_dumb * args)98 int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
99 struct drm_mode_create_dumb *args)
100 {
101 struct mtk_drm_gem_obj *mtk_gem;
102 int ret;
103
104 args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
105 args->size = args->pitch * args->height;
106
107 mtk_gem = mtk_drm_gem_create(dev, args->size, false);
108 if (IS_ERR(mtk_gem))
109 return PTR_ERR(mtk_gem);
110
111 /*
112 * allocate a id of idr table where the obj is registered
113 * and handle has the id what user can see.
114 */
115 ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
116 if (ret)
117 goto err_handle_create;
118
119 /* drop reference from allocate - handle holds it now. */
120 drm_gem_object_put(&mtk_gem->base);
121
122 return 0;
123
124 err_handle_create:
125 mtk_drm_gem_free_object(&mtk_gem->base);
126 return ret;
127 }
128
mtk_drm_gem_object_mmap(struct drm_gem_object * obj,struct vm_area_struct * vma)129 static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
130 struct vm_area_struct *vma)
131
132 {
133 int ret;
134 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
135 struct mtk_drm_private *priv = obj->dev->dev_private;
136
137 /*
138 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
139 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
140 */
141 vma->vm_flags &= ~VM_PFNMAP;
142
143 ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
144 mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
145 if (ret)
146 drm_gem_vm_close(vma);
147
148 return ret;
149 }
150
mtk_drm_gem_mmap_buf(struct drm_gem_object * obj,struct vm_area_struct * vma)151 int mtk_drm_gem_mmap_buf(struct drm_gem_object *obj, struct vm_area_struct *vma)
152 {
153 int ret;
154
155 ret = drm_gem_mmap_obj(obj, obj->size, vma);
156 if (ret)
157 return ret;
158
159 return mtk_drm_gem_object_mmap(obj, vma);
160 }
161
mtk_drm_gem_mmap(struct file * filp,struct vm_area_struct * vma)162 int mtk_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
163 {
164 struct drm_gem_object *obj;
165 int ret;
166
167 ret = drm_gem_mmap(filp, vma);
168 if (ret)
169 return ret;
170
171 obj = vma->vm_private_data;
172
173 /*
174 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
175 * whole buffer from the start.
176 */
177 vma->vm_pgoff = 0;
178
179 return mtk_drm_gem_object_mmap(obj, vma);
180 }
181
182 /*
183 * Allocate a sg_table for this GEM object.
184 * Note: Both the table's contents, and the sg_table itself must be freed by
185 * the caller.
186 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
187 */
mtk_gem_prime_get_sg_table(struct drm_gem_object * obj)188 struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
189 {
190 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
191 struct mtk_drm_private *priv = obj->dev->dev_private;
192 struct sg_table *sgt;
193 int ret;
194
195 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
196 if (!sgt)
197 return ERR_PTR(-ENOMEM);
198
199 ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
200 mtk_gem->dma_addr, obj->size,
201 mtk_gem->dma_attrs);
202 if (ret) {
203 DRM_ERROR("failed to allocate sgt, %d\n", ret);
204 kfree(sgt);
205 return ERR_PTR(ret);
206 }
207
208 return sgt;
209 }
210
mtk_gem_prime_import_sg_table(struct drm_device * dev,struct dma_buf_attachment * attach,struct sg_table * sg)211 struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
212 struct dma_buf_attachment *attach, struct sg_table *sg)
213 {
214 struct mtk_drm_gem_obj *mtk_gem;
215
216 /* check if the entries in the sg_table are contiguous */
217 if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
218 DRM_ERROR("sg_table is not contiguous");
219 return ERR_PTR(-EINVAL);
220 }
221
222 mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
223 if (IS_ERR(mtk_gem))
224 return ERR_CAST(mtk_gem);
225
226 mtk_gem->dma_addr = sg_dma_address(sg->sgl);
227 mtk_gem->sg = sg;
228
229 return &mtk_gem->base;
230 }
231
mtk_drm_gem_prime_vmap(struct drm_gem_object * obj)232 void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
233 {
234 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
235 struct sg_table *sgt;
236 unsigned int npages;
237
238 if (mtk_gem->kvaddr)
239 return mtk_gem->kvaddr;
240
241 sgt = mtk_gem_prime_get_sg_table(obj);
242 if (IS_ERR(sgt))
243 return NULL;
244
245 npages = obj->size >> PAGE_SHIFT;
246 mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
247 if (!mtk_gem->pages)
248 goto out;
249
250 drm_prime_sg_to_page_addr_arrays(sgt, mtk_gem->pages, NULL, npages);
251
252 mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
253 pgprot_writecombine(PAGE_KERNEL));
254
255 out:
256 kfree(sgt);
257
258 return mtk_gem->kvaddr;
259 }
260
mtk_drm_gem_prime_vunmap(struct drm_gem_object * obj,void * vaddr)261 void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
262 {
263 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
264
265 if (!mtk_gem->pages)
266 return;
267
268 vunmap(vaddr);
269 mtk_gem->kvaddr = 0;
270 kfree(mtk_gem->pages);
271 }
272