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_gem_dma_helper.h>
12 #include <drm/drm_prime.h>
13
14 #include "mtk_drm_drv.h"
15 #include "mtk_drm_gem.h"
16
17 static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
18
19 static const struct vm_operations_struct vm_ops = {
20 .open = drm_gem_vm_open,
21 .close = drm_gem_vm_close,
22 };
23
24 static const struct drm_gem_object_funcs mtk_drm_gem_object_funcs = {
25 .free = mtk_drm_gem_free_object,
26 .get_sg_table = mtk_gem_prime_get_sg_table,
27 .vmap = mtk_drm_gem_prime_vmap,
28 .vunmap = mtk_drm_gem_prime_vunmap,
29 .mmap = mtk_drm_gem_object_mmap,
30 .vm_ops = &vm_ops,
31 };
32
mtk_drm_gem_init(struct drm_device * dev,unsigned long size)33 static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
34 unsigned long size)
35 {
36 struct mtk_drm_gem_obj *mtk_gem_obj;
37 int ret;
38
39 size = round_up(size, PAGE_SIZE);
40
41 if (size == 0)
42 return ERR_PTR(-EINVAL);
43
44 mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
45 if (!mtk_gem_obj)
46 return ERR_PTR(-ENOMEM);
47
48 mtk_gem_obj->base.funcs = &mtk_drm_gem_object_funcs;
49
50 ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
51 if (ret < 0) {
52 DRM_ERROR("failed to initialize gem object\n");
53 kfree(mtk_gem_obj);
54 return ERR_PTR(ret);
55 }
56
57 return mtk_gem_obj;
58 }
59
mtk_drm_gem_create(struct drm_device * dev,size_t size,bool alloc_kmap)60 struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
61 size_t size, bool alloc_kmap)
62 {
63 struct mtk_drm_private *priv = dev->dev_private;
64 struct mtk_drm_gem_obj *mtk_gem;
65 struct drm_gem_object *obj;
66 int ret;
67
68 mtk_gem = mtk_drm_gem_init(dev, size);
69 if (IS_ERR(mtk_gem))
70 return ERR_CAST(mtk_gem);
71
72 obj = &mtk_gem->base;
73
74 mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
75
76 if (!alloc_kmap)
77 mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
78
79 mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
80 &mtk_gem->dma_addr, GFP_KERNEL,
81 mtk_gem->dma_attrs);
82 if (!mtk_gem->cookie) {
83 DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
84 ret = -ENOMEM;
85 goto err_gem_free;
86 }
87
88 if (alloc_kmap)
89 mtk_gem->kvaddr = mtk_gem->cookie;
90
91 DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
92 mtk_gem->cookie, &mtk_gem->dma_addr,
93 size);
94
95 return mtk_gem;
96
97 err_gem_free:
98 drm_gem_object_release(obj);
99 kfree(mtk_gem);
100 return ERR_PTR(ret);
101 }
102
mtk_drm_gem_free_object(struct drm_gem_object * obj)103 void mtk_drm_gem_free_object(struct drm_gem_object *obj)
104 {
105 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
106 struct mtk_drm_private *priv = obj->dev->dev_private;
107
108 if (mtk_gem->sg)
109 drm_prime_gem_destroy(obj, mtk_gem->sg);
110 else
111 dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
112 mtk_gem->dma_addr, mtk_gem->dma_attrs);
113
114 /* release file pointer to gem object. */
115 drm_gem_object_release(obj);
116
117 kfree(mtk_gem);
118 }
119
mtk_drm_gem_dumb_create(struct drm_file * file_priv,struct drm_device * dev,struct drm_mode_create_dumb * args)120 int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
121 struct drm_mode_create_dumb *args)
122 {
123 struct mtk_drm_gem_obj *mtk_gem;
124 int ret;
125
126 args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
127
128 /*
129 * Multiply 2 variables of different types,
130 * for example: args->size = args->spacing * args->height;
131 * may cause coverity issue with unintentional overflow.
132 */
133 args->size = args->pitch;
134 args->size *= args->height;
135
136 mtk_gem = mtk_drm_gem_create(dev, args->size, false);
137 if (IS_ERR(mtk_gem))
138 return PTR_ERR(mtk_gem);
139
140 /*
141 * allocate a id of idr table where the obj is registered
142 * and handle has the id what user can see.
143 */
144 ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
145 if (ret)
146 goto err_handle_create;
147
148 /* drop reference from allocate - handle holds it now. */
149 drm_gem_object_put(&mtk_gem->base);
150
151 return 0;
152
153 err_handle_create:
154 mtk_drm_gem_free_object(&mtk_gem->base);
155 return ret;
156 }
157
mtk_drm_gem_object_mmap(struct drm_gem_object * obj,struct vm_area_struct * vma)158 static int mtk_drm_gem_object_mmap(struct drm_gem_object *obj,
159 struct vm_area_struct *vma)
160
161 {
162 int ret;
163 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
164 struct mtk_drm_private *priv = obj->dev->dev_private;
165
166 /*
167 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
168 * whole buffer from the start.
169 */
170 vma->vm_pgoff = 0;
171
172 /*
173 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
174 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
175 */
176 vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
177 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
178 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
179
180 ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
181 mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
182
183 return ret;
184 }
185
186 /*
187 * Allocate a sg_table for this GEM object.
188 * Note: Both the table's contents, and the sg_table itself must be freed by
189 * the caller.
190 * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
191 */
mtk_gem_prime_get_sg_table(struct drm_gem_object * obj)192 struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
193 {
194 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
195 struct mtk_drm_private *priv = obj->dev->dev_private;
196 struct sg_table *sgt;
197 int ret;
198
199 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
200 if (!sgt)
201 return ERR_PTR(-ENOMEM);
202
203 ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
204 mtk_gem->dma_addr, obj->size,
205 mtk_gem->dma_attrs);
206 if (ret) {
207 DRM_ERROR("failed to allocate sgt, %d\n", ret);
208 kfree(sgt);
209 return ERR_PTR(ret);
210 }
211
212 return sgt;
213 }
214
mtk_gem_prime_import_sg_table(struct drm_device * dev,struct dma_buf_attachment * attach,struct sg_table * sg)215 struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
216 struct dma_buf_attachment *attach, struct sg_table *sg)
217 {
218 struct mtk_drm_gem_obj *mtk_gem;
219
220 /* check if the entries in the sg_table are contiguous */
221 if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
222 DRM_ERROR("sg_table is not contiguous");
223 return ERR_PTR(-EINVAL);
224 }
225
226 mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
227 if (IS_ERR(mtk_gem))
228 return ERR_CAST(mtk_gem);
229
230 mtk_gem->dma_addr = sg_dma_address(sg->sgl);
231 mtk_gem->sg = sg;
232
233 return &mtk_gem->base;
234 }
235
mtk_drm_gem_prime_vmap(struct drm_gem_object * obj,struct iosys_map * map)236 int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
237 {
238 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
239 struct sg_table *sgt = NULL;
240 unsigned int npages;
241
242 if (mtk_gem->kvaddr)
243 goto out;
244
245 sgt = mtk_gem_prime_get_sg_table(obj);
246 if (IS_ERR(sgt))
247 return PTR_ERR(sgt);
248
249 npages = obj->size >> PAGE_SHIFT;
250 mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
251 if (!mtk_gem->pages) {
252 sg_free_table(sgt);
253 kfree(sgt);
254 return -ENOMEM;
255 }
256
257 drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
258
259 mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
260 pgprot_writecombine(PAGE_KERNEL));
261 if (!mtk_gem->kvaddr) {
262 sg_free_table(sgt);
263 kfree(sgt);
264 kfree(mtk_gem->pages);
265 return -ENOMEM;
266 }
267 sg_free_table(sgt);
268 kfree(sgt);
269
270 out:
271 iosys_map_set_vaddr(map, mtk_gem->kvaddr);
272
273 return 0;
274 }
275
mtk_drm_gem_prime_vunmap(struct drm_gem_object * obj,struct iosys_map * map)276 void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj,
277 struct iosys_map *map)
278 {
279 struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
280 void *vaddr = map->vaddr;
281
282 if (!mtk_gem->pages)
283 return;
284
285 vunmap(vaddr);
286 mtk_gem->kvaddr = NULL;
287 kfree(mtk_gem->pages);
288 }
289