1 // SPDX-License-Identifier: MIT
2
3 #include <linux/export.h>
4 #include <linux/fb.h>
5 #include <linux/vmalloc.h>
6
7 #include <drm/drm_drv.h>
8 #include <drm/drm_fbdev_dma.h>
9 #include <drm/drm_fb_dma_helper.h>
10 #include <drm/drm_fb_helper.h>
11 #include <drm/drm_framebuffer.h>
12 #include <drm/drm_gem_dma_helper.h>
13
14 /*
15 * struct fb_ops
16 */
17
drm_fbdev_dma_fb_open(struct fb_info * info,int user)18 static int drm_fbdev_dma_fb_open(struct fb_info *info, int user)
19 {
20 struct drm_fb_helper *fb_helper = info->par;
21
22 /* No need to take a ref for fbcon because it unbinds on unregister */
23 if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
24 return -ENODEV;
25
26 return 0;
27 }
28
drm_fbdev_dma_fb_release(struct fb_info * info,int user)29 static int drm_fbdev_dma_fb_release(struct fb_info *info, int user)
30 {
31 struct drm_fb_helper *fb_helper = info->par;
32
33 if (user)
34 module_put(fb_helper->dev->driver->fops->owner);
35
36 return 0;
37 }
38
drm_fbdev_dma_fb_mmap(struct fb_info * info,struct vm_area_struct * vma)39 static int drm_fbdev_dma_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
40 {
41 struct drm_fb_helper *fb_helper = info->par;
42
43 return drm_gem_prime_mmap(fb_helper->buffer->gem, vma);
44 }
45
drm_fbdev_dma_fb_destroy(struct fb_info * info)46 static void drm_fbdev_dma_fb_destroy(struct fb_info *info)
47 {
48 struct drm_fb_helper *fb_helper = info->par;
49
50 if (!fb_helper->dev)
51 return;
52
53 if (info->fbdefio)
54 fb_deferred_io_cleanup(info);
55 drm_fb_helper_fini(fb_helper);
56
57 drm_client_buffer_vunmap(fb_helper->buffer);
58 drm_client_framebuffer_delete(fb_helper->buffer);
59 drm_client_release(&fb_helper->client);
60 drm_fb_helper_unprepare(fb_helper);
61 kfree(fb_helper);
62 }
63
64 static const struct fb_ops drm_fbdev_dma_fb_ops = {
65 .owner = THIS_MODULE,
66 .fb_open = drm_fbdev_dma_fb_open,
67 .fb_release = drm_fbdev_dma_fb_release,
68 __FB_DEFAULT_DMAMEM_OPS_RDWR,
69 DRM_FB_HELPER_DEFAULT_OPS,
70 __FB_DEFAULT_DMAMEM_OPS_DRAW,
71 .fb_mmap = drm_fbdev_dma_fb_mmap,
72 .fb_destroy = drm_fbdev_dma_fb_destroy,
73 };
74
75 FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(drm_fbdev_dma_shadowed,
76 drm_fb_helper_damage_range,
77 drm_fb_helper_damage_area);
78
drm_fbdev_dma_shadowed_fb_destroy(struct fb_info * info)79 static void drm_fbdev_dma_shadowed_fb_destroy(struct fb_info *info)
80 {
81 struct drm_fb_helper *fb_helper = info->par;
82 void *shadow = info->screen_buffer;
83
84 if (!fb_helper->dev)
85 return;
86
87 if (info->fbdefio)
88 fb_deferred_io_cleanup(info);
89 drm_fb_helper_fini(fb_helper);
90 vfree(shadow);
91
92 drm_client_buffer_vunmap(fb_helper->buffer);
93 drm_client_framebuffer_delete(fb_helper->buffer);
94 drm_client_release(&fb_helper->client);
95 drm_fb_helper_unprepare(fb_helper);
96 kfree(fb_helper);
97 }
98
99 static const struct fb_ops drm_fbdev_dma_shadowed_fb_ops = {
100 .owner = THIS_MODULE,
101 .fb_open = drm_fbdev_dma_fb_open,
102 .fb_release = drm_fbdev_dma_fb_release,
103 FB_DEFAULT_DEFERRED_OPS(drm_fbdev_dma_shadowed),
104 DRM_FB_HELPER_DEFAULT_OPS,
105 .fb_destroy = drm_fbdev_dma_shadowed_fb_destroy,
106 };
107
108 /*
109 * struct drm_fb_helper
110 */
111
drm_fbdev_dma_damage_blit_real(struct drm_fb_helper * fb_helper,struct drm_clip_rect * clip,struct iosys_map * dst)112 static void drm_fbdev_dma_damage_blit_real(struct drm_fb_helper *fb_helper,
113 struct drm_clip_rect *clip,
114 struct iosys_map *dst)
115 {
116 struct drm_framebuffer *fb = fb_helper->fb;
117 size_t offset = clip->y1 * fb->pitches[0];
118 size_t len = clip->x2 - clip->x1;
119 unsigned int y;
120 void *src;
121
122 switch (drm_format_info_bpp(fb->format, 0)) {
123 case 1:
124 offset += clip->x1 / 8;
125 len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
126 break;
127 case 2:
128 offset += clip->x1 / 4;
129 len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
130 break;
131 case 4:
132 offset += clip->x1 / 2;
133 len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
134 break;
135 default:
136 offset += clip->x1 * fb->format->cpp[0];
137 len *= fb->format->cpp[0];
138 break;
139 }
140
141 src = fb_helper->info->screen_buffer + offset;
142 iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
143
144 for (y = clip->y1; y < clip->y2; y++) {
145 iosys_map_memcpy_to(dst, 0, src, len);
146 iosys_map_incr(dst, fb->pitches[0]);
147 src += fb->pitches[0];
148 }
149 }
150
drm_fbdev_dma_damage_blit(struct drm_fb_helper * fb_helper,struct drm_clip_rect * clip)151 static int drm_fbdev_dma_damage_blit(struct drm_fb_helper *fb_helper,
152 struct drm_clip_rect *clip)
153 {
154 struct drm_client_buffer *buffer = fb_helper->buffer;
155 struct iosys_map dst;
156
157 /*
158 * For fbdev emulation, we only have to protect against fbdev modeset
159 * operations. Nothing else will involve the client buffer's BO. So it
160 * is sufficient to acquire struct drm_fb_helper.lock here.
161 */
162 mutex_lock(&fb_helper->lock);
163
164 dst = buffer->map;
165 drm_fbdev_dma_damage_blit_real(fb_helper, clip, &dst);
166
167 mutex_unlock(&fb_helper->lock);
168
169 return 0;
170 }
drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper * helper,struct drm_clip_rect * clip)171 static int drm_fbdev_dma_helper_fb_dirty(struct drm_fb_helper *helper,
172 struct drm_clip_rect *clip)
173 {
174 struct drm_device *dev = helper->dev;
175 int ret;
176
177 /* Call damage handlers only if necessary */
178 if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
179 return 0;
180
181 if (helper->fb->funcs->dirty) {
182 ret = drm_fbdev_dma_damage_blit(helper, clip);
183 if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
184 return ret;
185
186 ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
187 if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
188 return ret;
189 }
190
191 return 0;
192 }
193
194 static const struct drm_fb_helper_funcs drm_fbdev_dma_helper_funcs = {
195 .fb_dirty = drm_fbdev_dma_helper_fb_dirty,
196 };
197
198 /*
199 * struct drm_fb_helper
200 */
201
drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)202 static int drm_fbdev_dma_driver_fbdev_probe_tail(struct drm_fb_helper *fb_helper,
203 struct drm_fb_helper_surface_size *sizes)
204 {
205 struct drm_device *dev = fb_helper->dev;
206 struct drm_client_buffer *buffer = fb_helper->buffer;
207 struct drm_gem_dma_object *dma_obj = to_drm_gem_dma_obj(buffer->gem);
208 struct drm_framebuffer *fb = fb_helper->fb;
209 struct fb_info *info = fb_helper->info;
210 struct iosys_map map = buffer->map;
211
212 info->fbops = &drm_fbdev_dma_fb_ops;
213
214 /* screen */
215 info->flags |= FBINFO_VIRTFB; /* system memory */
216 if (dma_obj->map_noncoherent)
217 info->flags |= FBINFO_READS_FAST; /* signal caching */
218 info->screen_size = sizes->surface_height * fb->pitches[0];
219 info->screen_buffer = map.vaddr;
220 if (!(info->flags & FBINFO_HIDE_SMEM_START)) {
221 if (!drm_WARN_ON(dev, is_vmalloc_addr(info->screen_buffer)))
222 info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
223 }
224 info->fix.smem_len = info->screen_size;
225
226 return 0;
227 }
228
drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)229 static int drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(struct drm_fb_helper *fb_helper,
230 struct drm_fb_helper_surface_size *sizes)
231 {
232 struct drm_client_buffer *buffer = fb_helper->buffer;
233 struct fb_info *info = fb_helper->info;
234 size_t screen_size = buffer->gem->size;
235 void *screen_buffer;
236 int ret;
237
238 /*
239 * Deferred I/O requires struct page for framebuffer memory,
240 * which is not guaranteed for all DMA ranges. We thus create
241 * a shadow buffer in system memory.
242 */
243 screen_buffer = vzalloc(screen_size);
244 if (!screen_buffer)
245 return -ENOMEM;
246
247 info->fbops = &drm_fbdev_dma_shadowed_fb_ops;
248
249 /* screen */
250 info->flags |= FBINFO_VIRTFB; /* system memory */
251 info->flags |= FBINFO_READS_FAST; /* signal caching */
252 info->screen_buffer = screen_buffer;
253 info->fix.smem_len = screen_size;
254
255 fb_helper->fbdefio.delay = HZ / 20;
256 fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
257
258 info->fbdefio = &fb_helper->fbdefio;
259 ret = fb_deferred_io_init(info);
260 if (ret)
261 goto err_vfree;
262
263 return 0;
264
265 err_vfree:
266 vfree(screen_buffer);
267 return ret;
268 }
269
drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper * fb_helper,struct drm_fb_helper_surface_size * sizes)270 int drm_fbdev_dma_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
271 struct drm_fb_helper_surface_size *sizes)
272 {
273 struct drm_client_dev *client = &fb_helper->client;
274 struct drm_device *dev = fb_helper->dev;
275 struct drm_client_buffer *buffer;
276 struct drm_framebuffer *fb;
277 struct fb_info *info;
278 u32 format;
279 struct iosys_map map;
280 int ret;
281
282 drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
283 sizes->surface_width, sizes->surface_height,
284 sizes->surface_bpp);
285
286 format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
287 sizes->surface_depth);
288 buffer = drm_client_framebuffer_create(client, sizes->surface_width,
289 sizes->surface_height, format);
290 if (IS_ERR(buffer))
291 return PTR_ERR(buffer);
292
293 fb = buffer->fb;
294
295 ret = drm_client_buffer_vmap(buffer, &map);
296 if (ret) {
297 goto err_drm_client_buffer_delete;
298 } else if (drm_WARN_ON(dev, map.is_iomem)) {
299 ret = -ENODEV; /* I/O memory not supported; use generic emulation */
300 goto err_drm_client_buffer_delete;
301 }
302
303 fb_helper->funcs = &drm_fbdev_dma_helper_funcs;
304 fb_helper->buffer = buffer;
305 fb_helper->fb = fb;
306
307 info = drm_fb_helper_alloc_info(fb_helper);
308 if (IS_ERR(info)) {
309 ret = PTR_ERR(info);
310 goto err_drm_client_buffer_vunmap;
311 }
312
313 drm_fb_helper_fill_info(info, fb_helper, sizes);
314
315 if (fb->funcs->dirty)
316 ret = drm_fbdev_dma_driver_fbdev_probe_tail_shadowed(fb_helper, sizes);
317 else
318 ret = drm_fbdev_dma_driver_fbdev_probe_tail(fb_helper, sizes);
319 if (ret)
320 goto err_drm_fb_helper_release_info;
321
322 return 0;
323
324 err_drm_fb_helper_release_info:
325 drm_fb_helper_release_info(fb_helper);
326 err_drm_client_buffer_vunmap:
327 fb_helper->fb = NULL;
328 fb_helper->buffer = NULL;
329 drm_client_buffer_vunmap(buffer);
330 err_drm_client_buffer_delete:
331 drm_client_framebuffer_delete(buffer);
332 return ret;
333 }
334 EXPORT_SYMBOL(drm_fbdev_dma_driver_fbdev_probe);
335