Line data Source code
1 : // SPDX-License-Identifier: MIT
2 :
3 : #include <linux/moduleparam.h>
4 : #include <linux/vmalloc.h>
5 :
6 : #include <drm/drm_crtc_helper.h>
7 : #include <drm/drm_drv.h>
8 : #include <drm/drm_fb_helper.h>
9 : #include <drm/drm_framebuffer.h>
10 : #include <drm/drm_gem.h>
11 : #include <drm/drm_print.h>
12 :
13 : #include <drm/drm_fbdev_generic.h>
14 :
15 : /* @user: 1=userspace, 0=fbcon */
16 0 : static int drm_fbdev_generic_fb_open(struct fb_info *info, int user)
17 : {
18 0 : struct drm_fb_helper *fb_helper = info->par;
19 :
20 : /* No need to take a ref for fbcon because it unbinds on unregister */
21 : if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
22 : return -ENODEV;
23 :
24 : return 0;
25 : }
26 :
27 0 : static int drm_fbdev_generic_fb_release(struct fb_info *info, int user)
28 : {
29 0 : struct drm_fb_helper *fb_helper = info->par;
30 :
31 : if (user)
32 : module_put(fb_helper->dev->driver->fops->owner);
33 :
34 0 : return 0;
35 : }
36 :
37 0 : FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_generic,
38 : drm_fb_helper_damage_range,
39 : drm_fb_helper_damage_area);
40 :
41 0 : static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
42 : {
43 0 : struct drm_fb_helper *fb_helper = info->par;
44 0 : void *shadow = info->screen_buffer;
45 :
46 0 : if (!fb_helper->dev)
47 : return;
48 :
49 0 : fb_deferred_io_cleanup(info);
50 0 : drm_fb_helper_fini(fb_helper);
51 0 : vfree(shadow);
52 0 : drm_client_framebuffer_delete(fb_helper->buffer);
53 :
54 0 : drm_client_release(&fb_helper->client);
55 0 : drm_fb_helper_unprepare(fb_helper);
56 0 : kfree(fb_helper);
57 : }
58 :
59 : static const struct fb_ops drm_fbdev_generic_fb_ops = {
60 : .owner = THIS_MODULE,
61 : .fb_open = drm_fbdev_generic_fb_open,
62 : .fb_release = drm_fbdev_generic_fb_release,
63 : FB_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),
64 : DRM_FB_HELPER_DEFAULT_OPS,
65 : .fb_destroy = drm_fbdev_generic_fb_destroy,
66 : };
67 :
68 : /*
69 : * This function uses the client API to create a framebuffer backed by a dumb buffer.
70 : */
71 0 : static int drm_fbdev_generic_helper_fb_probe(struct drm_fb_helper *fb_helper,
72 : struct drm_fb_helper_surface_size *sizes)
73 : {
74 0 : struct drm_client_dev *client = &fb_helper->client;
75 0 : struct drm_device *dev = fb_helper->dev;
76 : struct drm_client_buffer *buffer;
77 : struct fb_info *info;
78 : size_t screen_size;
79 : void *screen_buffer;
80 : u32 format;
81 : int ret;
82 :
83 0 : drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
84 : sizes->surface_width, sizes->surface_height,
85 : sizes->surface_bpp);
86 :
87 0 : format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
88 0 : buffer = drm_client_framebuffer_create(client, sizes->surface_width,
89 : sizes->surface_height, format);
90 0 : if (IS_ERR(buffer))
91 0 : return PTR_ERR(buffer);
92 :
93 0 : fb_helper->buffer = buffer;
94 0 : fb_helper->fb = buffer->fb;
95 :
96 0 : screen_size = buffer->gem->size;
97 0 : screen_buffer = vzalloc(screen_size);
98 0 : if (!screen_buffer) {
99 : ret = -ENOMEM;
100 : goto err_drm_client_framebuffer_delete;
101 : }
102 :
103 0 : info = drm_fb_helper_alloc_info(fb_helper);
104 0 : if (IS_ERR(info)) {
105 0 : ret = PTR_ERR(info);
106 0 : goto err_vfree;
107 : }
108 :
109 0 : drm_fb_helper_fill_info(info, fb_helper, sizes);
110 :
111 0 : info->fbops = &drm_fbdev_generic_fb_ops;
112 :
113 : /* screen */
114 0 : info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
115 0 : info->screen_buffer = screen_buffer;
116 0 : info->fix.smem_start = page_to_phys(vmalloc_to_page(info->screen_buffer));
117 0 : info->fix.smem_len = screen_size;
118 :
119 : /* deferred I/O */
120 0 : fb_helper->fbdefio.delay = HZ / 20;
121 0 : fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
122 :
123 0 : info->fbdefio = &fb_helper->fbdefio;
124 0 : ret = fb_deferred_io_init(info);
125 0 : if (ret)
126 : goto err_drm_fb_helper_release_info;
127 :
128 : return 0;
129 :
130 : err_drm_fb_helper_release_info:
131 0 : drm_fb_helper_release_info(fb_helper);
132 : err_vfree:
133 0 : vfree(screen_buffer);
134 : err_drm_client_framebuffer_delete:
135 0 : fb_helper->fb = NULL;
136 0 : fb_helper->buffer = NULL;
137 0 : drm_client_framebuffer_delete(buffer);
138 0 : return ret;
139 : }
140 :
141 0 : static void drm_fbdev_generic_damage_blit_real(struct drm_fb_helper *fb_helper,
142 : struct drm_clip_rect *clip,
143 : struct iosys_map *dst)
144 : {
145 0 : struct drm_framebuffer *fb = fb_helper->fb;
146 0 : size_t offset = clip->y1 * fb->pitches[0];
147 0 : size_t len = clip->x2 - clip->x1;
148 : unsigned int y;
149 : void *src;
150 :
151 0 : switch (drm_format_info_bpp(fb->format, 0)) {
152 : case 1:
153 0 : offset += clip->x1 / 8;
154 0 : len = DIV_ROUND_UP(len + clip->x1 % 8, 8);
155 : break;
156 : case 2:
157 0 : offset += clip->x1 / 4;
158 0 : len = DIV_ROUND_UP(len + clip->x1 % 4, 4);
159 : break;
160 : case 4:
161 0 : offset += clip->x1 / 2;
162 0 : len = DIV_ROUND_UP(len + clip->x1 % 2, 2);
163 : break;
164 : default:
165 0 : offset += clip->x1 * fb->format->cpp[0];
166 0 : len *= fb->format->cpp[0];
167 : break;
168 : }
169 :
170 0 : src = fb_helper->info->screen_buffer + offset;
171 0 : iosys_map_incr(dst, offset); /* go to first pixel within clip rect */
172 :
173 0 : for (y = clip->y1; y < clip->y2; y++) {
174 0 : iosys_map_memcpy_to(dst, 0, src, len);
175 0 : iosys_map_incr(dst, fb->pitches[0]);
176 0 : src += fb->pitches[0];
177 : }
178 0 : }
179 :
180 0 : static int drm_fbdev_generic_damage_blit(struct drm_fb_helper *fb_helper,
181 : struct drm_clip_rect *clip)
182 : {
183 0 : struct drm_client_buffer *buffer = fb_helper->buffer;
184 : struct iosys_map map, dst;
185 : int ret;
186 :
187 : /*
188 : * We have to pin the client buffer to its current location while
189 : * flushing the shadow buffer. In the general case, concurrent
190 : * modesetting operations could try to move the buffer and would
191 : * fail. The modeset has to be serialized by acquiring the reservation
192 : * object of the underlying BO here.
193 : *
194 : * For fbdev emulation, we only have to protect against fbdev modeset
195 : * operations. Nothing else will involve the client buffer's BO. So it
196 : * is sufficient to acquire struct drm_fb_helper.lock here.
197 : */
198 0 : mutex_lock(&fb_helper->lock);
199 :
200 0 : ret = drm_client_buffer_vmap(buffer, &map);
201 0 : if (ret)
202 : goto out;
203 :
204 0 : dst = map;
205 0 : drm_fbdev_generic_damage_blit_real(fb_helper, clip, &dst);
206 :
207 0 : drm_client_buffer_vunmap(buffer);
208 :
209 : out:
210 0 : mutex_unlock(&fb_helper->lock);
211 :
212 0 : return ret;
213 : }
214 :
215 0 : static int drm_fbdev_generic_helper_fb_dirty(struct drm_fb_helper *helper,
216 : struct drm_clip_rect *clip)
217 : {
218 0 : struct drm_device *dev = helper->dev;
219 : int ret;
220 :
221 : /* Call damage handlers only if necessary */
222 0 : if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
223 : return 0;
224 :
225 0 : ret = drm_fbdev_generic_damage_blit(helper, clip);
226 0 : if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))
227 : return ret;
228 :
229 0 : if (helper->fb->funcs->dirty) {
230 0 : ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
231 0 : if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
232 : return ret;
233 : }
234 :
235 : return 0;
236 : }
237 :
238 : static const struct drm_fb_helper_funcs drm_fbdev_generic_helper_funcs = {
239 : .fb_probe = drm_fbdev_generic_helper_fb_probe,
240 : .fb_dirty = drm_fbdev_generic_helper_fb_dirty,
241 : };
242 :
243 0 : static void drm_fbdev_generic_client_unregister(struct drm_client_dev *client)
244 : {
245 0 : struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
246 :
247 0 : if (fb_helper->info) {
248 0 : drm_fb_helper_unregister_info(fb_helper);
249 : } else {
250 0 : drm_client_release(&fb_helper->client);
251 0 : drm_fb_helper_unprepare(fb_helper);
252 0 : kfree(fb_helper);
253 : }
254 0 : }
255 :
256 0 : static int drm_fbdev_generic_client_restore(struct drm_client_dev *client)
257 : {
258 0 : drm_fb_helper_lastclose(client->dev);
259 :
260 0 : return 0;
261 : }
262 :
263 0 : static int drm_fbdev_generic_client_hotplug(struct drm_client_dev *client)
264 : {
265 0 : struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
266 0 : struct drm_device *dev = client->dev;
267 : int ret;
268 :
269 0 : if (dev->fb_helper)
270 0 : return drm_fb_helper_hotplug_event(dev->fb_helper);
271 :
272 0 : ret = drm_fb_helper_init(dev, fb_helper);
273 0 : if (ret)
274 : goto err_drm_err;
275 :
276 0 : if (!drm_drv_uses_atomic_modeset(dev))
277 0 : drm_helper_disable_unused_functions(dev);
278 :
279 0 : ret = drm_fb_helper_initial_config(fb_helper);
280 0 : if (ret)
281 : goto err_drm_fb_helper_fini;
282 :
283 : return 0;
284 :
285 : err_drm_fb_helper_fini:
286 0 : drm_fb_helper_fini(fb_helper);
287 : err_drm_err:
288 0 : drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
289 0 : return ret;
290 : }
291 :
292 : static const struct drm_client_funcs drm_fbdev_generic_client_funcs = {
293 : .owner = THIS_MODULE,
294 : .unregister = drm_fbdev_generic_client_unregister,
295 : .restore = drm_fbdev_generic_client_restore,
296 : .hotplug = drm_fbdev_generic_client_hotplug,
297 : };
298 :
299 : /**
300 : * drm_fbdev_generic_setup() - Setup generic fbdev emulation
301 : * @dev: DRM device
302 : * @preferred_bpp: Preferred bits per pixel for the device.
303 : *
304 : * This function sets up generic fbdev emulation for drivers that supports
305 : * dumb buffers with a virtual address and that can be mmap'ed.
306 : * drm_fbdev_generic_setup() shall be called after the DRM driver registered
307 : * the new DRM device with drm_dev_register().
308 : *
309 : * Restore, hotplug events and teardown are all taken care of. Drivers that do
310 : * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
311 : * Simple drivers might use drm_mode_config_helper_suspend().
312 : *
313 : * In order to provide fixed mmap-able memory ranges, generic fbdev emulation
314 : * uses a shadow buffer in system memory. The implementation blits the shadow
315 : * fbdev buffer onto the real buffer in regular intervals.
316 : *
317 : * This function is safe to call even when there are no connectors present.
318 : * Setup will be retried on the next hotplug event.
319 : *
320 : * The fbdev is destroyed by drm_dev_unregister().
321 : */
322 0 : void drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
323 : {
324 : struct drm_fb_helper *fb_helper;
325 : int ret;
326 :
327 0 : drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
328 0 : drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
329 :
330 0 : fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
331 0 : if (!fb_helper)
332 : return;
333 0 : drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_generic_helper_funcs);
334 :
335 0 : ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_generic_client_funcs);
336 0 : if (ret) {
337 0 : drm_err(dev, "Failed to register client: %d\n", ret);
338 : goto err_drm_client_init;
339 : }
340 :
341 0 : drm_client_register(&fb_helper->client);
342 :
343 0 : return;
344 :
345 : err_drm_client_init:
346 0 : drm_fb_helper_unprepare(fb_helper);
347 0 : kfree(fb_helper);
348 0 : return;
349 : }
350 : EXPORT_SYMBOL(drm_fbdev_generic_setup);
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