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

source code of linux/drivers/gpu/drm/mediatek/mtk_drm_gem.c