1 // SPDX-License-Identifier: MIT
2
3 #include <linux/fb.h>
4 #include <linux/vmalloc.h>
5
6 #include <drm/drm_drv.h>
7 #include <drm/drm_fbdev_dma.h>
8 #include <drm/drm_fb_dma_helper.h>
9 #include <drm/drm_fb_helper.h>
10 #include <drm/drm_framebuffer.h>
11 #include <drm/drm_gem_dma_helper.h>
12
13 /*
14 * struct fb_ops
15 */
16
drm_fbdev_dma_fb_open(struct fb_info * info,int user)17 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
18 {
19 struct drm_fb_helper *fb_helper = info->par;
20
21 /* No need to take a ref for fbcon because it unbinds on unregister */
22 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
23 return -ENODEV;
24
25 return 0;
26 }
27
drm_fbdev_dma_fb_release(struct fb_info * info,int user)28 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
29 {
30 struct drm_fb_helper *fb_helper = info->par;
31
32 if (user)
33 module_put(fb_helper->dev->driver->fops->owner);
34
35 return 0;
36 }
37
drm_fbdev_dma_fb_mmap(struct fb_info * info,struct vm_area_struct * vma)38 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
39 {
40 struct drm_fb_helper *fb_helper = info->par;
41
42 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);
43 }
44
drm_fbdev_dma_fb_destroy(struct fb_info * info)45 static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
46 {
47 struct drm_fb_helper *fb_helper = info->par;
48
49 if (!fb_helper->dev)
50 return;
51
52 if (info->fbdefio)
53 fb_deferred_io_cleanup(info);
54 drm_fb_helper_fini(fb_helper);
55
56 drm_client_buffer_vunmap(fb_helper->buffer);
57 drm_client_framebuffer_delete(fb_helper->buffer);
58 drm_client_release(&fb_helper->client);
59 drm_fb_helper_unprepare(fb_helper);
60 kfree(fb_helper);
61 }
62
63 static const struct fb_ops drm_fbdev_dma_fb_ops = {
64 .owner = THIS_MODULE,
65 .fb_open = drm_fbdev_dma_fb_open,
66 .fb_release = drm_fbdev_dma_fb_release,
67 __FB_DEFAULT_DMAMEM_OPS_RDWR,
68 DRM_FB_HELPER_DEFAULT_OPS,
69 __FB_DEFAULT_DMAMEM_OPS_DRAW,
70 .fb_mmap = drm_fbdev_dma_fb_mmap,
71 .fb_destroy = drm_fbdev_dma_fb_destroy,
72 };
73
74 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma_shadowed,
75 drm_fb_helper_damage_range,
76 drm_fb_helper_damage_area);
77
drm_fbdev_dma_shadowed_fb_destroy(struct fb_info * info)78 static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
79 {
80 struct drm_fb_helper *fb_helper = info->par;
81 void *shadow = info->screen_buffer;
82
83 if (!fb_helper->dev)
84 return;
85
86 if (info->fbdefio)
87 fb_deferred_io_cleanup(info);
88 drm_fb_helper_fini(fb_helper);
89 vfree(shadow);
90
91 drm_client_buffer_vunmap(fb_helper->buffer);
92 drm_client_framebuffer_delete(fb_helper->buffer);
93 drm_client_release(&fb_helper->client);
94 drm_fb_helper_unprepare(fb_helper);
95 kfree(fb_helper);
96 }
97
98 static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
99 .owner = THIS_MODULE,
100 .fb_open = drm_fbdev_dma_fb_open,
101 .fb_release = drm_fbdev_dma_fb_release,
102 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_dma_shadowed),
103 DRM_FB_HELPER_DEFAULT_OPS,
104 .fb_destroy = drm_fbdev_dma_shadowed_fb_destroy,
105 };
106
107 /*
108 * struct drm_fb_helper
109 */
110
drm_fbdev_dma_damage_blit_real(struct drm_fb_helper * fb_helper,struct drm_clip_rect * clip,struct iosys_map * dst)111 static void drm_fbdev_dma_damage_blit_real(struct drm_fb_helper *fb_helper,
112 struct drm_clip_rect *clip,
113 struct iosys_map *dst)
114 {
115 struct drm_framebuffer *fb = fb_helper->fb;
116 size_t offset = clip->y1 * fb->pitches[0];
117 size_t len = clip->x2 - clip->x1;
118 unsigned int y;
119 void *src;
120
121 switch (drm_format_info_bpp(fb->format, 0)) {
122 case 1:
123 offset += clip->x1 / 8;
124 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
125 break;
126 case 2:
127 offset += clip->x1 / 4;
128 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
129 break;
130 case 4:
131 offset += clip->x1 / 2;
132 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
133 break;
134 default:
135 offset += clip->x1 * fb->format->cpp[0];
136 len *= fb->format->cpp[0];
137 break;
138 }
139
140 src = fb_helper->info->screen_buffer + offset;
141 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
142
143 for (y = clip->y1; y < clip->y2; y++) {
144 iosys_map_memcpy_to(dst, 0, src, len);
145 iosys_map_incr(dst, fb->pitches[0]);
146 src += fb->pitches[0];
147 }
148 }
149
drm_fbdev_dma_damage_blit(struct drm_fb_helper * fb_helper,struct drm_clip_rect * clip)150 static int drm_fbdev_dma_damage_blit(struct drm_fb_helper *fb_helper,
151 struct drm_clip_rect *clip)
152 {
153 struct drm_client_buffer *buffer = fb_helper->buffer;
154 struct iosys_map dst;
155
156 /*
157 * For fbdev emulation, we only have to protect against fbdev modeset
158 * operations. Nothing else will involve the client buffer's BO. So it
159 * is sufficient to acquire struct drm_fb_helper.lock here.
160 */
161 mutex_lock(&fb_helper->lock);
162
163 dst = buffer->map;
164 drm_fbdev_dma_damage_blit_real(fb_helper, clip, &dst);
165
166 mutex_unlock(&fb_helper->lock);
167
168 return 0;
169 }
drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper * helper,struct drm_clip_rect * clip)170 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,
171 struct drm_clip_rect *clip)
172 {
173 struct drm_device *dev = helper->dev;
174 int ret;
175
176 /* Call damage handlers only if necessary */
177 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
178 return 0;
179
180 if (helper->fb->funcs->dirty) {
181 ret = drm_fbdev_dma_damage_blit(helper, clip);
182 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
183 return ret;
184
185 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
186 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
187 return ret;
188 }
189
190 return 0;
191 }
192
193 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
194 .fb_dirty = drm_fbdev_dma_helper_fb_dirty,
195 };
196
197 /*
198 * struct drm_fb_helper
199 */
200
drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)201 static int drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper *fb_helper,
202 struct drm_fb_helper_surface_size *sizes)
203 {
204 struct drm_device *dev = fb_helper->dev;
205 struct drm_client_buffer *buffer = fb_helper->buffer;
206 struct drm_gem_dma_object *dma_obj = to_drm_gem_dma_obj(buffer->gem);
207 struct drm_framebuffer *fb = fb_helper->fb;
208 struct fb_info *info = fb_helper->info;
209 struct iosys_map map = buffer->map;
210
211 info->fbops = &drm_fbdev_dma_fb_ops;
212
213 /* screen */
214 info->flags |= FBINFO_VIRTFB; /* system memory */
215 if (dma_obj->map_noncoherent)
216 info->flags |= FBINFO_READS_FAST; /* signal caching */
217 info->screen_size = sizes->surface_height * fb->pitches[0];
218 info->screen_buffer = map.vaddr;
219 if (!(info->flags & FBINFO_HIDE_SMEM_START)) {
220 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))
221 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
222 }
223 info->fix.smem_len = info->screen_size;
224
225 return 0;
226 }
227
drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)228 static int drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper *fb_helper,
229 struct drm_fb_helper_surface_size *sizes)
230 {
231 struct drm_client_buffer *buffer = fb_helper->buffer;
232 struct fb_info *info = fb_helper->info;
233 size_t screen_size = buffer->gem->size;
234 void *screen_buffer;
235 int ret;
236
237 /*
238 * Deferred I/O requires struct page for framebuffer memory,
239 * which is not guaranteed for all DMA ranges. We thus create
240 * a shadow buffer in system memory.
241 */
242 screen_buffer = vzalloc(screen_size);
243 if (!screen_buffer)
244 return -ENOMEM;
245
246 info->fbops = &drm_fbdev_dma_shadowed_fb_ops;
247
248 /* screen */
249 info->flags |= FBINFO_VIRTFB; /* system memory */
250 info->flags |= FBINFO_READS_FAST; /* signal caching */
251 info->screen_buffer = screen_buffer;
252 info->fix.smem_len = screen_size;
253
254 fb_helper->fbdefio.delay = HZ / 20;
255 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
256
257 info->fbdefio = &fb_helper->fbdefio;
258 ret = fb_deferred_io_init(info);
259 if (ret)
260 goto err_vfree;
261
262 return 0;
263
264 err_vfree:
265 vfree(screen_buffer);
266 return ret;
267 }
268
drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)269 int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
270 struct drm_fb_helper_surface_size *sizes)
271 {
272 struct drm_client_dev *client = &fb_helper->client;
273 struct drm_device *dev = fb_helper->dev;
274 struct drm_client_buffer *buffer;
275 struct drm_framebuffer *fb;
276 struct fb_info *info;
277 u32 format;
278 struct iosys_map map;
279 int ret;
280
281 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
282 sizes->surface_width, sizes->surface_height,
283 sizes->surface_bpp);
284
285 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
286 sizes->surface_depth);
287 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
288 sizes->surface_height, format);
289 if (IS_ERR(buffer))
290 return PTR_ERR(buffer);
291
292 fb = buffer->fb;
293
294 ret = drm_client_buffer_vmap(buffer, &map);
295 if (ret) {
296 goto err_drm_client_buffer_delete;
297 } else if (drm_WARN_ON(dev, map.is_iomem)) {
298 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
299 goto err_drm_client_buffer_delete;
300 }
301
302 fb_helper->funcs = &drm_fbdev_dma_helper_funcs;
303 fb_helper->buffer = buffer;
304 fb_helper->fb = fb;
305
306 info = drm_fb_helper_alloc_info(fb_helper);
307 if (IS_ERR(info)) {
308 ret = PTR_ERR(info);
309 goto err_drm_client_buffer_vunmap;
310 }
311
312 drm_fb_helper_fill_info(info, fb_helper, sizes);
313
314 if (fb->funcs->dirty)
315 ret = drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(fb_helper, sizes);
316 else
317 ret = drm_fbdev_dma_driver_fbdev_probe_tail(fb_helper, sizes);
318 if (ret)
319 goto err_drm_fb_helper_release_info;
320
321 return 0;
322
323 err_drm_fb_helper_release_info:
324 drm_fb_helper_release_info(fb_helper);
325 err_drm_client_buffer_vunmap:
326 fb_helper->fb = NULL;
327 fb_helper->buffer = NULL;
328 drm_client_buffer_vunmap(buffer);
329 err_drm_client_buffer_delete:
330 drm_client_framebuffer_delete(buffer);
331 return ret;
332 }
333 EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe);
334