GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / gpu / drm / drm_fb_helper.c
1 /*
2  * Copyright (c) 2006-2009 Red Hat Inc.
3  * Copyright (c) 2006-2008 Intel Corporation
4  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
5  *
6  * DRM framebuffer helper functions
7  *
8  * Permission to use, copy, modify, distribute, and sell this software and its
9  * documentation for any purpose is hereby granted without fee, provided that
10  * the above copyright notice appear in all copies and that both that copyright
11  * notice and this permission notice appear in supporting documentation, and
12  * that the name of the copyright holders not be used in advertising or
13  * publicity pertaining to distribution of the software without specific,
14  * written prior permission.  The copyright holders make no representations
15  * about the suitability of this software for any purpose.  It is provided "as
16  * is" without express or implied warranty.
17  *
18  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
20  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
21  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
22  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
23  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
24  * OF THIS SOFTWARE.
25  *
26  * Authors:
27  *      Dave Airlie <airlied@linux.ie>
28  *      Jesse Barnes <jesse.barnes@intel.com>
29  */
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31
32 #include <linux/console.h>
33 #include <linux/dma-buf.h>
34 #include <linux/kernel.h>
35 #include <linux/module.h>
36 #include <linux/slab.h>
37 #include <linux/sysrq.h>
38 #include <linux/vmalloc.h>
39
40 #include <drm/drm_atomic.h>
41 #include <drm/drm_crtc.h>
42 #include <drm/drm_crtc_helper.h>
43 #include <drm/drm_drv.h>
44 #include <drm/drm_fb_helper.h>
45 #include <drm/drm_fourcc.h>
46 #include <drm/drm_print.h>
47 #include <drm/drm_vblank.h>
48
49 #include "drm_crtc_helper_internal.h"
50 #include "drm_internal.h"
51
52 static bool drm_fbdev_emulation = true;
53 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
54 MODULE_PARM_DESC(fbdev_emulation,
55                  "Enable legacy fbdev emulation [default=true]");
56
57 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
58 module_param(drm_fbdev_overalloc, int, 0444);
59 MODULE_PARM_DESC(drm_fbdev_overalloc,
60                  "Overallocation of the fbdev buffer (%) [default="
61                  __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
62
63 /*
64  * In order to keep user-space compatibility, we want in certain use-cases
65  * to keep leaking the fbdev physical address to the user-space program
66  * handling the fbdev buffer.
67  * This is a bad habit essentially kept into closed source opengl driver
68  * that should really be moved into open-source upstream projects instead
69  * of using legacy physical addresses in user space to communicate with
70  * other out-of-tree kernel modules.
71  *
72  * This module_param *should* be removed as soon as possible and be
73  * considered as a broken and legacy behaviour from a modern fbdev device.
74  */
75 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
76 static bool drm_leak_fbdev_smem = false;
77 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
78 MODULE_PARM_DESC(drm_leak_fbdev_smem,
79                  "Allow unsafe leaking fbdev physical smem address [default=false]");
80 #endif
81
82 static LIST_HEAD(kernel_fb_helper_list);
83 static DEFINE_MUTEX(kernel_fb_helper_lock);
84
85 /**
86  * DOC: fbdev helpers
87  *
88  * The fb helper functions are useful to provide an fbdev on top of a drm kernel
89  * mode setting driver. They can be used mostly independently from the crtc
90  * helper functions used by many drivers to implement the kernel mode setting
91  * interfaces.
92  *
93  * Drivers that support a dumb buffer with a virtual address and mmap support,
94  * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
95  * It will automatically set up deferred I/O if the driver requires a shadow
96  * buffer.
97  *
98  * At runtime drivers should restore the fbdev console by using
99  * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
100  * They should also notify the fb helper code from updates to the output
101  * configuration by using drm_fb_helper_output_poll_changed() as their
102  * &drm_mode_config_funcs.output_poll_changed callback.
103  *
104  * For suspend/resume consider using drm_mode_config_helper_suspend() and
105  * drm_mode_config_helper_resume() which takes care of fbdev as well.
106  *
107  * All other functions exported by the fb helper library can be used to
108  * implement the fbdev driver interface by the driver.
109  *
110  * It is possible, though perhaps somewhat tricky, to implement race-free
111  * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
112  * helper must be called first to initialize the minimum required to make
113  * hotplug detection work. Drivers also need to make sure to properly set up
114  * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
115  * it is safe to enable interrupts and start processing hotplug events. At the
116  * same time, drivers should initialize all modeset objects such as CRTCs,
117  * encoders and connectors. To finish up the fbdev helper initialization, the
118  * drm_fb_helper_init() function is called. To probe for all attached displays
119  * and set up an initial configuration using the detected hardware, drivers
120  * should call drm_fb_helper_initial_config().
121  *
122  * If &drm_framebuffer_funcs.dirty is set, the
123  * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
124  * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
125  * away. This worker then calls the dirty() function ensuring that it will
126  * always run in process context since the fb_*() function could be running in
127  * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
128  * callback it will also schedule dirty_work with the damage collected from the
129  * mmap page writes.
130  *
131  * Deferred I/O is not compatible with SHMEM. Such drivers should request an
132  * fbdev shadow buffer and call drm_fbdev_generic_setup() instead.
133  */
134
135 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
136 {
137         uint16_t *r_base, *g_base, *b_base;
138
139         if (crtc->funcs->gamma_set == NULL)
140                 return;
141
142         r_base = crtc->gamma_store;
143         g_base = r_base + crtc->gamma_size;
144         b_base = g_base + crtc->gamma_size;
145
146         crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
147                                crtc->gamma_size, NULL);
148 }
149
150 /**
151  * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
152  * @info: fbdev registered by the helper
153  */
154 int drm_fb_helper_debug_enter(struct fb_info *info)
155 {
156         struct drm_fb_helper *helper = info->par;
157         const struct drm_crtc_helper_funcs *funcs;
158         struct drm_mode_set *mode_set;
159
160         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
161                 mutex_lock(&helper->client.modeset_mutex);
162                 drm_client_for_each_modeset(mode_set, &helper->client) {
163                         if (!mode_set->crtc->enabled)
164                                 continue;
165
166                         funcs = mode_set->crtc->helper_private;
167                         if (funcs->mode_set_base_atomic == NULL)
168                                 continue;
169
170                         if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
171                                 continue;
172
173                         funcs->mode_set_base_atomic(mode_set->crtc,
174                                                     mode_set->fb,
175                                                     mode_set->x,
176                                                     mode_set->y,
177                                                     ENTER_ATOMIC_MODE_SET);
178                 }
179                 mutex_unlock(&helper->client.modeset_mutex);
180         }
181
182         return 0;
183 }
184 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
185
186 /**
187  * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
188  * @info: fbdev registered by the helper
189  */
190 int drm_fb_helper_debug_leave(struct fb_info *info)
191 {
192         struct drm_fb_helper *helper = info->par;
193         struct drm_client_dev *client = &helper->client;
194         struct drm_device *dev = helper->dev;
195         struct drm_crtc *crtc;
196         const struct drm_crtc_helper_funcs *funcs;
197         struct drm_mode_set *mode_set;
198         struct drm_framebuffer *fb;
199
200         mutex_lock(&client->modeset_mutex);
201         drm_client_for_each_modeset(mode_set, client) {
202                 crtc = mode_set->crtc;
203                 if (drm_drv_uses_atomic_modeset(crtc->dev))
204                         continue;
205
206                 funcs = crtc->helper_private;
207                 fb = crtc->primary->fb;
208
209                 if (!crtc->enabled)
210                         continue;
211
212                 if (!fb) {
213                         drm_err(dev, "no fb to restore?\n");
214                         continue;
215                 }
216
217                 if (funcs->mode_set_base_atomic == NULL)
218                         continue;
219
220                 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
221                 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
222                                             crtc->y, LEAVE_ATOMIC_MODE_SET);
223         }
224         mutex_unlock(&client->modeset_mutex);
225
226         return 0;
227 }
228 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
229
230 static int
231 __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
232                                             bool force)
233 {
234         bool do_delayed;
235         int ret;
236
237         if (!drm_fbdev_emulation || !fb_helper)
238                 return -ENODEV;
239
240         if (READ_ONCE(fb_helper->deferred_setup))
241                 return 0;
242
243         mutex_lock(&fb_helper->lock);
244         if (force) {
245                 /*
246                  * Yes this is the _locked version which expects the master lock
247                  * to be held. But for forced restores we're intentionally
248                  * racing here, see drm_fb_helper_set_par().
249                  */
250                 ret = drm_client_modeset_commit_locked(&fb_helper->client);
251         } else {
252                 ret = drm_client_modeset_commit(&fb_helper->client);
253         }
254
255         do_delayed = fb_helper->delayed_hotplug;
256         if (do_delayed)
257                 fb_helper->delayed_hotplug = false;
258         mutex_unlock(&fb_helper->lock);
259
260         if (do_delayed)
261                 drm_fb_helper_hotplug_event(fb_helper);
262
263         return ret;
264 }
265
266 /**
267  * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
268  * @fb_helper: driver-allocated fbdev helper, can be NULL
269  *
270  * This should be called from driver's drm &drm_driver.lastclose callback
271  * when implementing an fbcon on top of kms using this helper. This ensures that
272  * the user isn't greeted with a black screen when e.g. X dies.
273  *
274  * RETURNS:
275  * Zero if everything went ok, negative error code otherwise.
276  */
277 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
278 {
279         return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
280 }
281 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
282
283 #ifdef CONFIG_MAGIC_SYSRQ
284 /*
285  * restore fbcon display for all kms driver's using this helper, used for sysrq
286  * and panic handling.
287  */
288 static bool drm_fb_helper_force_kernel_mode(void)
289 {
290         bool ret, error = false;
291         struct drm_fb_helper *helper;
292
293         if (list_empty(&kernel_fb_helper_list))
294                 return false;
295
296         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
297                 struct drm_device *dev = helper->dev;
298
299                 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
300                         continue;
301
302                 mutex_lock(&helper->lock);
303                 ret = drm_client_modeset_commit_locked(&helper->client);
304                 if (ret)
305                         error = true;
306                 mutex_unlock(&helper->lock);
307         }
308         return error;
309 }
310
311 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
312 {
313         bool ret;
314
315         ret = drm_fb_helper_force_kernel_mode();
316         if (ret == true)
317                 DRM_ERROR("Failed to restore crtc configuration\n");
318 }
319 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
320
321 static void drm_fb_helper_sysrq(int dummy1)
322 {
323         schedule_work(&drm_fb_helper_restore_work);
324 }
325
326 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
327         .handler = drm_fb_helper_sysrq,
328         .help_msg = "force-fb(v)",
329         .action_msg = "Restore framebuffer console",
330 };
331 #else
332 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
333 #endif
334
335 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
336 {
337         struct drm_fb_helper *fb_helper = info->par;
338
339         mutex_lock(&fb_helper->lock);
340         drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
341         mutex_unlock(&fb_helper->lock);
342 }
343
344 /**
345  * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
346  * @blank: desired blanking state
347  * @info: fbdev registered by the helper
348  */
349 int drm_fb_helper_blank(int blank, struct fb_info *info)
350 {
351         if (oops_in_progress)
352                 return -EBUSY;
353
354         switch (blank) {
355         /* Display: On; HSync: On, VSync: On */
356         case FB_BLANK_UNBLANK:
357                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
358                 break;
359         /* Display: Off; HSync: On, VSync: On */
360         case FB_BLANK_NORMAL:
361                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
362                 break;
363         /* Display: Off; HSync: Off, VSync: On */
364         case FB_BLANK_HSYNC_SUSPEND:
365                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
366                 break;
367         /* Display: Off; HSync: On, VSync: Off */
368         case FB_BLANK_VSYNC_SUSPEND:
369                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
370                 break;
371         /* Display: Off; HSync: Off, VSync: Off */
372         case FB_BLANK_POWERDOWN:
373                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
374                 break;
375         }
376         return 0;
377 }
378 EXPORT_SYMBOL(drm_fb_helper_blank);
379
380 static void drm_fb_helper_resume_worker(struct work_struct *work)
381 {
382         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
383                                                     resume_work);
384
385         console_lock();
386         fb_set_suspend(helper->fbdev, 0);
387         console_unlock();
388 }
389
390 static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
391                                           struct drm_clip_rect *clip)
392 {
393         struct drm_framebuffer *fb = fb_helper->fb;
394         unsigned int cpp = fb->format->cpp[0];
395         size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
396         void *src = fb_helper->fbdev->screen_buffer + offset;
397         void *dst = fb_helper->buffer->vaddr + offset;
398         size_t len = (clip->x2 - clip->x1) * cpp;
399         unsigned int y;
400
401         for (y = clip->y1; y < clip->y2; y++) {
402                 if (!fb_helper->dev->mode_config.fbdev_use_iomem)
403                         memcpy(dst, src, len);
404                 else
405                         memcpy_toio((void __iomem *)dst, src, len);
406
407                 src += fb->pitches[0];
408                 dst += fb->pitches[0];
409         }
410 }
411
412 static void drm_fb_helper_dirty_work(struct work_struct *work)
413 {
414         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
415                                                     dirty_work);
416         struct drm_clip_rect *clip = &helper->dirty_clip;
417         struct drm_clip_rect clip_copy;
418         unsigned long flags;
419         void *vaddr;
420
421         spin_lock_irqsave(&helper->dirty_lock, flags);
422         clip_copy = *clip;
423         clip->x1 = clip->y1 = ~0;
424         clip->x2 = clip->y2 = 0;
425         spin_unlock_irqrestore(&helper->dirty_lock, flags);
426
427         /* call dirty callback only when it has been really touched */
428         if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
429
430                 /* Generic fbdev uses a shadow buffer */
431                 if (helper->buffer) {
432                         vaddr = drm_client_buffer_vmap(helper->buffer);
433                         if (IS_ERR(vaddr))
434                                 return;
435                         drm_fb_helper_dirty_blit_real(helper, &clip_copy);
436                 }
437                 if (helper->fb->funcs->dirty)
438                         helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
439                                                  &clip_copy, 1);
440
441                 if (helper->buffer)
442                         drm_client_buffer_vunmap(helper->buffer);
443         }
444 }
445
446 /**
447  * drm_fb_helper_prepare - setup a drm_fb_helper structure
448  * @dev: DRM device
449  * @helper: driver-allocated fbdev helper structure to set up
450  * @funcs: pointer to structure of functions associate with this helper
451  *
452  * Sets up the bare minimum to make the framebuffer helper usable. This is
453  * useful to implement race-free initialization of the polling helpers.
454  */
455 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
456                            const struct drm_fb_helper_funcs *funcs)
457 {
458         INIT_LIST_HEAD(&helper->kernel_fb_list);
459         spin_lock_init(&helper->dirty_lock);
460         INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
461         INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
462         helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
463         mutex_init(&helper->lock);
464         helper->funcs = funcs;
465         helper->dev = dev;
466 }
467 EXPORT_SYMBOL(drm_fb_helper_prepare);
468
469 /**
470  * drm_fb_helper_init - initialize a &struct drm_fb_helper
471  * @dev: drm device
472  * @fb_helper: driver-allocated fbdev helper structure to initialize
473  *
474  * This allocates the structures for the fbdev helper with the given limits.
475  * Note that this won't yet touch the hardware (through the driver interfaces)
476  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
477  * to allow driver writes more control over the exact init sequence.
478  *
479  * Drivers must call drm_fb_helper_prepare() before calling this function.
480  *
481  * RETURNS:
482  * Zero if everything went ok, nonzero otherwise.
483  */
484 int drm_fb_helper_init(struct drm_device *dev,
485                        struct drm_fb_helper *fb_helper)
486 {
487         int ret;
488
489         if (!drm_fbdev_emulation) {
490                 dev->fb_helper = fb_helper;
491                 return 0;
492         }
493
494         /*
495          * If this is not the generic fbdev client, initialize a drm_client
496          * without callbacks so we can use the modesets.
497          */
498         if (!fb_helper->client.funcs) {
499                 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
500                 if (ret)
501                         return ret;
502         }
503
504         dev->fb_helper = fb_helper;
505
506         return 0;
507 }
508 EXPORT_SYMBOL(drm_fb_helper_init);
509
510 /**
511  * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
512  * @fb_helper: driver-allocated fbdev helper
513  *
514  * A helper to alloc fb_info and the members cmap and apertures. Called
515  * by the driver within the fb_probe fb_helper callback function. Drivers do not
516  * need to release the allocated fb_info structure themselves, this is
517  * automatically done when calling drm_fb_helper_fini().
518  *
519  * RETURNS:
520  * fb_info pointer if things went okay, pointer containing error code
521  * otherwise
522  */
523 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
524 {
525         struct device *dev = fb_helper->dev->dev;
526         struct fb_info *info;
527         int ret;
528
529         info = framebuffer_alloc(0, dev);
530         if (!info)
531                 return ERR_PTR(-ENOMEM);
532
533         ret = fb_alloc_cmap(&info->cmap, 256, 0);
534         if (ret)
535                 goto err_release;
536
537         /*
538          * TODO: We really should be smarter here and alloc an apperture
539          * for each IORESOURCE_MEM resource helper->dev->dev has and also
540          * init the ranges of the appertures based on the resources.
541          * Note some drivers currently count on there being only 1 empty
542          * aperture and fill this themselves, these will need to be dealt
543          * with somehow when fixing this.
544          */
545         info->apertures = alloc_apertures(1);
546         if (!info->apertures) {
547                 ret = -ENOMEM;
548                 goto err_free_cmap;
549         }
550
551         fb_helper->fbdev = info;
552         info->skip_vt_switch = true;
553
554         return info;
555
556 err_free_cmap:
557         fb_dealloc_cmap(&info->cmap);
558 err_release:
559         framebuffer_release(info);
560         return ERR_PTR(ret);
561 }
562 EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
563
564 /**
565  * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
566  * @fb_helper: driver-allocated fbdev helper, can be NULL
567  *
568  * A wrapper around unregister_framebuffer, to release the fb_info
569  * framebuffer device. This must be called before releasing all resources for
570  * @fb_helper by calling drm_fb_helper_fini().
571  */
572 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
573 {
574         if (fb_helper && fb_helper->fbdev)
575                 unregister_framebuffer(fb_helper->fbdev);
576 }
577 EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
578
579 /**
580  * drm_fb_helper_fini - finialize a &struct drm_fb_helper
581  * @fb_helper: driver-allocated fbdev helper, can be NULL
582  *
583  * This cleans up all remaining resources associated with @fb_helper.
584  */
585 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
586 {
587         struct fb_info *info;
588
589         if (!fb_helper)
590                 return;
591
592         fb_helper->dev->fb_helper = NULL;
593
594         if (!drm_fbdev_emulation)
595                 return;
596
597         cancel_work_sync(&fb_helper->resume_work);
598         cancel_work_sync(&fb_helper->dirty_work);
599
600         info = fb_helper->fbdev;
601         if (info) {
602                 if (info->cmap.len)
603                         fb_dealloc_cmap(&info->cmap);
604                 framebuffer_release(info);
605         }
606         fb_helper->fbdev = NULL;
607
608         mutex_lock(&kernel_fb_helper_lock);
609         if (!list_empty(&fb_helper->kernel_fb_list)) {
610                 list_del(&fb_helper->kernel_fb_list);
611                 if (list_empty(&kernel_fb_helper_list))
612                         unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
613         }
614         mutex_unlock(&kernel_fb_helper_lock);
615
616         mutex_destroy(&fb_helper->lock);
617
618         if (!fb_helper->client.funcs)
619                 drm_client_release(&fb_helper->client);
620 }
621 EXPORT_SYMBOL(drm_fb_helper_fini);
622
623 static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
624 {
625         struct drm_device *dev = fb_helper->dev;
626         struct drm_framebuffer *fb = fb_helper->fb;
627
628         return dev->mode_config.prefer_shadow_fbdev ||
629                dev->mode_config.prefer_shadow ||
630                fb->funcs->dirty;
631 }
632
633 static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
634                                 u32 width, u32 height)
635 {
636         struct drm_fb_helper *helper = info->par;
637         struct drm_clip_rect *clip = &helper->dirty_clip;
638         unsigned long flags;
639
640         if (!drm_fbdev_use_shadow_fb(helper))
641                 return;
642
643         spin_lock_irqsave(&helper->dirty_lock, flags);
644         clip->x1 = min_t(u32, clip->x1, x);
645         clip->y1 = min_t(u32, clip->y1, y);
646         clip->x2 = max_t(u32, clip->x2, x + width);
647         clip->y2 = max_t(u32, clip->y2, y + height);
648         spin_unlock_irqrestore(&helper->dirty_lock, flags);
649
650         schedule_work(&helper->dirty_work);
651 }
652
653 /**
654  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
655  * @info: fb_info struct pointer
656  * @pagelist: list of dirty mmap framebuffer pages
657  *
658  * This function is used as the &fb_deferred_io.deferred_io
659  * callback function for flushing the fbdev mmap writes.
660  */
661 void drm_fb_helper_deferred_io(struct fb_info *info,
662                                struct list_head *pagelist)
663 {
664         unsigned long start, end, min, max;
665         struct page *page;
666         u32 y1, y2;
667
668         min = ULONG_MAX;
669         max = 0;
670         list_for_each_entry(page, pagelist, lru) {
671                 start = page->index << PAGE_SHIFT;
672                 end = start + PAGE_SIZE - 1;
673                 min = min(min, start);
674                 max = max(max, end);
675         }
676
677         if (min < max) {
678                 y1 = min / info->fix.line_length;
679                 y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
680                            info->var.yres);
681                 drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
682         }
683 }
684 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
685
686 /**
687  * drm_fb_helper_sys_read - wrapper around fb_sys_read
688  * @info: fb_info struct pointer
689  * @buf: userspace buffer to read from framebuffer memory
690  * @count: number of bytes to read from framebuffer memory
691  * @ppos: read offset within framebuffer memory
692  *
693  * A wrapper around fb_sys_read implemented by fbdev core
694  */
695 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
696                                size_t count, loff_t *ppos)
697 {
698         return fb_sys_read(info, buf, count, ppos);
699 }
700 EXPORT_SYMBOL(drm_fb_helper_sys_read);
701
702 /**
703  * drm_fb_helper_sys_write - wrapper around fb_sys_write
704  * @info: fb_info struct pointer
705  * @buf: userspace buffer to write to framebuffer memory
706  * @count: number of bytes to write to framebuffer memory
707  * @ppos: write offset within framebuffer memory
708  *
709  * A wrapper around fb_sys_write implemented by fbdev core
710  */
711 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
712                                 size_t count, loff_t *ppos)
713 {
714         ssize_t ret;
715
716         ret = fb_sys_write(info, buf, count, ppos);
717         if (ret > 0)
718                 drm_fb_helper_dirty(info, 0, 0, info->var.xres,
719                                     info->var.yres);
720
721         return ret;
722 }
723 EXPORT_SYMBOL(drm_fb_helper_sys_write);
724
725 /**
726  * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
727  * @info: fbdev registered by the helper
728  * @rect: info about rectangle to fill
729  *
730  * A wrapper around sys_fillrect implemented by fbdev core
731  */
732 void drm_fb_helper_sys_fillrect(struct fb_info *info,
733                                 const struct fb_fillrect *rect)
734 {
735         sys_fillrect(info, rect);
736         drm_fb_helper_dirty(info, rect->dx, rect->dy,
737                             rect->width, rect->height);
738 }
739 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
740
741 /**
742  * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
743  * @info: fbdev registered by the helper
744  * @area: info about area to copy
745  *
746  * A wrapper around sys_copyarea implemented by fbdev core
747  */
748 void drm_fb_helper_sys_copyarea(struct fb_info *info,
749                                 const struct fb_copyarea *area)
750 {
751         sys_copyarea(info, area);
752         drm_fb_helper_dirty(info, area->dx, area->dy,
753                             area->width, area->height);
754 }
755 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
756
757 /**
758  * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
759  * @info: fbdev registered by the helper
760  * @image: info about image to blit
761  *
762  * A wrapper around sys_imageblit implemented by fbdev core
763  */
764 void drm_fb_helper_sys_imageblit(struct fb_info *info,
765                                  const struct fb_image *image)
766 {
767         sys_imageblit(info, image);
768         drm_fb_helper_dirty(info, image->dx, image->dy,
769                             image->width, image->height);
770 }
771 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
772
773 /**
774  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
775  * @info: fbdev registered by the helper
776  * @rect: info about rectangle to fill
777  *
778  * A wrapper around cfb_fillrect implemented by fbdev core
779  */
780 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
781                                 const struct fb_fillrect *rect)
782 {
783         cfb_fillrect(info, rect);
784         drm_fb_helper_dirty(info, rect->dx, rect->dy,
785                             rect->width, rect->height);
786 }
787 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
788
789 /**
790  * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
791  * @info: fbdev registered by the helper
792  * @area: info about area to copy
793  *
794  * A wrapper around cfb_copyarea implemented by fbdev core
795  */
796 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
797                                 const struct fb_copyarea *area)
798 {
799         cfb_copyarea(info, area);
800         drm_fb_helper_dirty(info, area->dx, area->dy,
801                             area->width, area->height);
802 }
803 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
804
805 /**
806  * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
807  * @info: fbdev registered by the helper
808  * @image: info about image to blit
809  *
810  * A wrapper around cfb_imageblit implemented by fbdev core
811  */
812 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
813                                  const struct fb_image *image)
814 {
815         cfb_imageblit(info, image);
816         drm_fb_helper_dirty(info, image->dx, image->dy,
817                             image->width, image->height);
818 }
819 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
820
821 /**
822  * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
823  * @fb_helper: driver-allocated fbdev helper, can be NULL
824  * @suspend: whether to suspend or resume
825  *
826  * A wrapper around fb_set_suspend implemented by fbdev core.
827  * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
828  * the lock yourself
829  */
830 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
831 {
832         if (fb_helper && fb_helper->fbdev)
833                 fb_set_suspend(fb_helper->fbdev, suspend);
834 }
835 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
836
837 /**
838  * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
839  *                                      takes the console lock
840  * @fb_helper: driver-allocated fbdev helper, can be NULL
841  * @suspend: whether to suspend or resume
842  *
843  * A wrapper around fb_set_suspend() that takes the console lock. If the lock
844  * isn't available on resume, a worker is tasked with waiting for the lock
845  * to become available. The console lock can be pretty contented on resume
846  * due to all the printk activity.
847  *
848  * This function can be called multiple times with the same state since
849  * &fb_info.state is checked to see if fbdev is running or not before locking.
850  *
851  * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
852  */
853 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
854                                         bool suspend)
855 {
856         if (!fb_helper || !fb_helper->fbdev)
857                 return;
858
859         /* make sure there's no pending/ongoing resume */
860         flush_work(&fb_helper->resume_work);
861
862         if (suspend) {
863                 if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
864                         return;
865
866                 console_lock();
867
868         } else {
869                 if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
870                         return;
871
872                 if (!console_trylock()) {
873                         schedule_work(&fb_helper->resume_work);
874                         return;
875                 }
876         }
877
878         fb_set_suspend(fb_helper->fbdev, suspend);
879         console_unlock();
880 }
881 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
882
883 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
884 {
885         u32 *palette = (u32 *)info->pseudo_palette;
886         int i;
887
888         if (cmap->start + cmap->len > 16)
889                 return -EINVAL;
890
891         for (i = 0; i < cmap->len; ++i) {
892                 u16 red = cmap->red[i];
893                 u16 green = cmap->green[i];
894                 u16 blue = cmap->blue[i];
895                 u32 value;
896
897                 red >>= 16 - info->var.red.length;
898                 green >>= 16 - info->var.green.length;
899                 blue >>= 16 - info->var.blue.length;
900                 value = (red << info->var.red.offset) |
901                         (green << info->var.green.offset) |
902                         (blue << info->var.blue.offset);
903                 if (info->var.transp.length > 0) {
904                         u32 mask = (1 << info->var.transp.length) - 1;
905
906                         mask <<= info->var.transp.offset;
907                         value |= mask;
908                 }
909                 palette[cmap->start + i] = value;
910         }
911
912         return 0;
913 }
914
915 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
916 {
917         struct drm_fb_helper *fb_helper = info->par;
918         struct drm_mode_set *modeset;
919         struct drm_crtc *crtc;
920         u16 *r, *g, *b;
921         int ret = 0;
922
923         drm_modeset_lock_all(fb_helper->dev);
924         drm_client_for_each_modeset(modeset, &fb_helper->client) {
925                 crtc = modeset->crtc;
926                 if (!crtc->funcs->gamma_set || !crtc->gamma_size) {
927                         ret = -EINVAL;
928                         goto out;
929                 }
930
931                 if (cmap->start + cmap->len > crtc->gamma_size) {
932                         ret = -EINVAL;
933                         goto out;
934                 }
935
936                 r = crtc->gamma_store;
937                 g = r + crtc->gamma_size;
938                 b = g + crtc->gamma_size;
939
940                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
941                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
942                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
943
944                 ret = crtc->funcs->gamma_set(crtc, r, g, b,
945                                              crtc->gamma_size, NULL);
946                 if (ret)
947                         goto out;
948         }
949 out:
950         drm_modeset_unlock_all(fb_helper->dev);
951
952         return ret;
953 }
954
955 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
956                                                        struct fb_cmap *cmap)
957 {
958         struct drm_device *dev = crtc->dev;
959         struct drm_property_blob *gamma_lut;
960         struct drm_color_lut *lut;
961         int size = crtc->gamma_size;
962         int i;
963
964         if (!size || cmap->start + cmap->len > size)
965                 return ERR_PTR(-EINVAL);
966
967         gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
968         if (IS_ERR(gamma_lut))
969                 return gamma_lut;
970
971         lut = gamma_lut->data;
972         if (cmap->start || cmap->len != size) {
973                 u16 *r = crtc->gamma_store;
974                 u16 *g = r + crtc->gamma_size;
975                 u16 *b = g + crtc->gamma_size;
976
977                 for (i = 0; i < cmap->start; i++) {
978                         lut[i].red = r[i];
979                         lut[i].green = g[i];
980                         lut[i].blue = b[i];
981                 }
982                 for (i = cmap->start + cmap->len; i < size; i++) {
983                         lut[i].red = r[i];
984                         lut[i].green = g[i];
985                         lut[i].blue = b[i];
986                 }
987         }
988
989         for (i = 0; i < cmap->len; i++) {
990                 lut[cmap->start + i].red = cmap->red[i];
991                 lut[cmap->start + i].green = cmap->green[i];
992                 lut[cmap->start + i].blue = cmap->blue[i];
993         }
994
995         return gamma_lut;
996 }
997
998 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
999 {
1000         struct drm_fb_helper *fb_helper = info->par;
1001         struct drm_device *dev = fb_helper->dev;
1002         struct drm_property_blob *gamma_lut = NULL;
1003         struct drm_modeset_acquire_ctx ctx;
1004         struct drm_crtc_state *crtc_state;
1005         struct drm_atomic_state *state;
1006         struct drm_mode_set *modeset;
1007         struct drm_crtc *crtc;
1008         u16 *r, *g, *b;
1009         bool replaced;
1010         int ret = 0;
1011
1012         drm_modeset_acquire_init(&ctx, 0);
1013
1014         state = drm_atomic_state_alloc(dev);
1015         if (!state) {
1016                 ret = -ENOMEM;
1017                 goto out_ctx;
1018         }
1019
1020         state->acquire_ctx = &ctx;
1021 retry:
1022         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1023                 crtc = modeset->crtc;
1024
1025                 if (!gamma_lut)
1026                         gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1027                 if (IS_ERR(gamma_lut)) {
1028                         ret = PTR_ERR(gamma_lut);
1029                         gamma_lut = NULL;
1030                         goto out_state;
1031                 }
1032
1033                 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1034                 if (IS_ERR(crtc_state)) {
1035                         ret = PTR_ERR(crtc_state);
1036                         goto out_state;
1037                 }
1038
1039                 replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1040                                                       NULL);
1041                 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1042                 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1043                                                       gamma_lut);
1044                 crtc_state->color_mgmt_changed |= replaced;
1045         }
1046
1047         ret = drm_atomic_commit(state);
1048         if (ret)
1049                 goto out_state;
1050
1051         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1052                 crtc = modeset->crtc;
1053
1054                 r = crtc->gamma_store;
1055                 g = r + crtc->gamma_size;
1056                 b = g + crtc->gamma_size;
1057
1058                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1059                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1060                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1061         }
1062
1063 out_state:
1064         if (ret == -EDEADLK)
1065                 goto backoff;
1066
1067         drm_property_blob_put(gamma_lut);
1068         drm_atomic_state_put(state);
1069 out_ctx:
1070         drm_modeset_drop_locks(&ctx);
1071         drm_modeset_acquire_fini(&ctx);
1072
1073         return ret;
1074
1075 backoff:
1076         drm_atomic_state_clear(state);
1077         drm_modeset_backoff(&ctx);
1078         goto retry;
1079 }
1080
1081 /**
1082  * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1083  * @cmap: cmap to set
1084  * @info: fbdev registered by the helper
1085  */
1086 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1087 {
1088         struct drm_fb_helper *fb_helper = info->par;
1089         struct drm_device *dev = fb_helper->dev;
1090         int ret;
1091
1092         if (oops_in_progress)
1093                 return -EBUSY;
1094
1095         mutex_lock(&fb_helper->lock);
1096
1097         if (!drm_master_internal_acquire(dev)) {
1098                 ret = -EBUSY;
1099                 goto unlock;
1100         }
1101
1102         mutex_lock(&fb_helper->client.modeset_mutex);
1103         if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1104                 ret = setcmap_pseudo_palette(cmap, info);
1105         else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1106                 ret = setcmap_atomic(cmap, info);
1107         else
1108                 ret = setcmap_legacy(cmap, info);
1109         mutex_unlock(&fb_helper->client.modeset_mutex);
1110
1111         drm_master_internal_release(dev);
1112 unlock:
1113         mutex_unlock(&fb_helper->lock);
1114
1115         return ret;
1116 }
1117 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1118
1119 /**
1120  * drm_fb_helper_ioctl - legacy ioctl implementation
1121  * @info: fbdev registered by the helper
1122  * @cmd: ioctl command
1123  * @arg: ioctl argument
1124  *
1125  * A helper to implement the standard fbdev ioctl. Only
1126  * FBIO_WAITFORVSYNC is implemented for now.
1127  */
1128 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1129                         unsigned long arg)
1130 {
1131         struct drm_fb_helper *fb_helper = info->par;
1132         struct drm_device *dev = fb_helper->dev;
1133         struct drm_crtc *crtc;
1134         int ret = 0;
1135
1136         mutex_lock(&fb_helper->lock);
1137         if (!drm_master_internal_acquire(dev)) {
1138                 ret = -EBUSY;
1139                 goto unlock;
1140         }
1141
1142         switch (cmd) {
1143         case FBIO_WAITFORVSYNC:
1144                 /*
1145                  * Only consider the first CRTC.
1146                  *
1147                  * This ioctl is supposed to take the CRTC number as
1148                  * an argument, but in fbdev times, what that number
1149                  * was supposed to be was quite unclear, different
1150                  * drivers were passing that argument differently
1151                  * (some by reference, some by value), and most of the
1152                  * userspace applications were just hardcoding 0 as an
1153                  * argument.
1154                  *
1155                  * The first CRTC should be the integrated panel on
1156                  * most drivers, so this is the best choice we can
1157                  * make. If we're not smart enough here, one should
1158                  * just consider switch the userspace to KMS.
1159                  */
1160                 crtc = fb_helper->client.modesets[0].crtc;
1161
1162                 /*
1163                  * Only wait for a vblank event if the CRTC is
1164                  * enabled, otherwise just don't do anythintg,
1165                  * not even report an error.
1166                  */
1167                 ret = drm_crtc_vblank_get(crtc);
1168                 if (!ret) {
1169                         drm_crtc_wait_one_vblank(crtc);
1170                         drm_crtc_vblank_put(crtc);
1171                 }
1172
1173                 ret = 0;
1174                 break;
1175         default:
1176                 ret = -ENOTTY;
1177         }
1178
1179         drm_master_internal_release(dev);
1180 unlock:
1181         mutex_unlock(&fb_helper->lock);
1182         return ret;
1183 }
1184 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1185
1186 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1187                                       const struct fb_var_screeninfo *var_2)
1188 {
1189         return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1190                var_1->grayscale == var_2->grayscale &&
1191                var_1->red.offset == var_2->red.offset &&
1192                var_1->red.length == var_2->red.length &&
1193                var_1->red.msb_right == var_2->red.msb_right &&
1194                var_1->green.offset == var_2->green.offset &&
1195                var_1->green.length == var_2->green.length &&
1196                var_1->green.msb_right == var_2->green.msb_right &&
1197                var_1->blue.offset == var_2->blue.offset &&
1198                var_1->blue.length == var_2->blue.length &&
1199                var_1->blue.msb_right == var_2->blue.msb_right &&
1200                var_1->transp.offset == var_2->transp.offset &&
1201                var_1->transp.length == var_2->transp.length &&
1202                var_1->transp.msb_right == var_2->transp.msb_right;
1203 }
1204
1205 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1206                                          u8 depth)
1207 {
1208         switch (depth) {
1209         case 8:
1210                 var->red.offset = 0;
1211                 var->green.offset = 0;
1212                 var->blue.offset = 0;
1213                 var->red.length = 8; /* 8bit DAC */
1214                 var->green.length = 8;
1215                 var->blue.length = 8;
1216                 var->transp.offset = 0;
1217                 var->transp.length = 0;
1218                 break;
1219         case 15:
1220                 var->red.offset = 10;
1221                 var->green.offset = 5;
1222                 var->blue.offset = 0;
1223                 var->red.length = 5;
1224                 var->green.length = 5;
1225                 var->blue.length = 5;
1226                 var->transp.offset = 15;
1227                 var->transp.length = 1;
1228                 break;
1229         case 16:
1230                 var->red.offset = 11;
1231                 var->green.offset = 5;
1232                 var->blue.offset = 0;
1233                 var->red.length = 5;
1234                 var->green.length = 6;
1235                 var->blue.length = 5;
1236                 var->transp.offset = 0;
1237                 break;
1238         case 24:
1239                 var->red.offset = 16;
1240                 var->green.offset = 8;
1241                 var->blue.offset = 0;
1242                 var->red.length = 8;
1243                 var->green.length = 8;
1244                 var->blue.length = 8;
1245                 var->transp.offset = 0;
1246                 var->transp.length = 0;
1247                 break;
1248         case 32:
1249                 var->red.offset = 16;
1250                 var->green.offset = 8;
1251                 var->blue.offset = 0;
1252                 var->red.length = 8;
1253                 var->green.length = 8;
1254                 var->blue.length = 8;
1255                 var->transp.offset = 24;
1256                 var->transp.length = 8;
1257                 break;
1258         default:
1259                 break;
1260         }
1261 }
1262
1263 /**
1264  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1265  * @var: screeninfo to check
1266  * @info: fbdev registered by the helper
1267  */
1268 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1269                             struct fb_info *info)
1270 {
1271         struct drm_fb_helper *fb_helper = info->par;
1272         struct drm_framebuffer *fb = fb_helper->fb;
1273         struct drm_device *dev = fb_helper->dev;
1274
1275         if (in_dbg_master())
1276                 return -EINVAL;
1277
1278         if (var->pixclock != 0) {
1279                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1280                 var->pixclock = 0;
1281         }
1282
1283         if ((drm_format_info_block_width(fb->format, 0) > 1) ||
1284             (drm_format_info_block_height(fb->format, 0) > 1))
1285                 return -EINVAL;
1286
1287         /*
1288          * Changes struct fb_var_screeninfo are currently not pushed back
1289          * to KMS, hence fail if different settings are requested.
1290          */
1291         if (var->bits_per_pixel > fb->format->cpp[0] * 8 ||
1292             var->xres > fb->width || var->yres > fb->height ||
1293             var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1294                 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1295                           "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1296                           var->xres, var->yres, var->bits_per_pixel,
1297                           var->xres_virtual, var->yres_virtual,
1298                           fb->width, fb->height, fb->format->cpp[0] * 8);
1299                 return -EINVAL;
1300         }
1301
1302         var->xres_virtual = fb->width;
1303         var->yres_virtual = fb->height;
1304
1305         /*
1306          * Workaround for SDL 1.2, which is known to be setting all pixel format
1307          * fields values to zero in some cases. We treat this situation as a
1308          * kind of "use some reasonable autodetected values".
1309          */
1310         if (!var->red.offset     && !var->green.offset    &&
1311             !var->blue.offset    && !var->transp.offset   &&
1312             !var->red.length     && !var->green.length    &&
1313             !var->blue.length    && !var->transp.length   &&
1314             !var->red.msb_right  && !var->green.msb_right &&
1315             !var->blue.msb_right && !var->transp.msb_right) {
1316                 drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
1317         }
1318
1319         /*
1320          * Likewise, bits_per_pixel should be rounded up to a supported value.
1321          */
1322         var->bits_per_pixel = fb->format->cpp[0] * 8;
1323
1324         /*
1325          * drm fbdev emulation doesn't support changing the pixel format at all,
1326          * so reject all pixel format changing requests.
1327          */
1328         if (!drm_fb_pixel_format_equal(var, &info->var)) {
1329                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1330                 return -EINVAL;
1331         }
1332
1333         return 0;
1334 }
1335 EXPORT_SYMBOL(drm_fb_helper_check_var);
1336
1337 /**
1338  * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1339  * @info: fbdev registered by the helper
1340  *
1341  * This will let fbcon do the mode init and is called at initialization time by
1342  * the fbdev core when registering the driver, and later on through the hotplug
1343  * callback.
1344  */
1345 int drm_fb_helper_set_par(struct fb_info *info)
1346 {
1347         struct drm_fb_helper *fb_helper = info->par;
1348         struct fb_var_screeninfo *var = &info->var;
1349         bool force;
1350
1351         if (oops_in_progress)
1352                 return -EBUSY;
1353
1354         if (var->pixclock != 0) {
1355                 drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1356                 return -EINVAL;
1357         }
1358
1359         /*
1360          * Normally we want to make sure that a kms master takes precedence over
1361          * fbdev, to avoid fbdev flickering and occasionally stealing the
1362          * display status. But Xorg first sets the vt back to text mode using
1363          * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1364          * status when exiting.
1365          *
1366          * In the past this was caught by drm_fb_helper_lastclose(), but on
1367          * modern systems where logind always keeps a drm fd open to orchestrate
1368          * the vt switching, this doesn't work.
1369          *
1370          * To not break the userspace ABI we have this special case here, which
1371          * is only used for the above case. Everything else uses the normal
1372          * commit function, which ensures that we never steal the display from
1373          * an active drm master.
1374          */
1375         force = var->activate & FB_ACTIVATE_KD_TEXT;
1376
1377         __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1378
1379         return 0;
1380 }
1381 EXPORT_SYMBOL(drm_fb_helper_set_par);
1382
1383 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1384 {
1385         struct drm_mode_set *mode_set;
1386
1387         mutex_lock(&fb_helper->client.modeset_mutex);
1388         drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1389                 mode_set->x = x;
1390                 mode_set->y = y;
1391         }
1392         mutex_unlock(&fb_helper->client.modeset_mutex);
1393 }
1394
1395 static int pan_display_atomic(struct fb_var_screeninfo *var,
1396                               struct fb_info *info)
1397 {
1398         struct drm_fb_helper *fb_helper = info->par;
1399         int ret;
1400
1401         pan_set(fb_helper, var->xoffset, var->yoffset);
1402
1403         ret = drm_client_modeset_commit_locked(&fb_helper->client);
1404         if (!ret) {
1405                 info->var.xoffset = var->xoffset;
1406                 info->var.yoffset = var->yoffset;
1407         } else
1408                 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1409
1410         return ret;
1411 }
1412
1413 static int pan_display_legacy(struct fb_var_screeninfo *var,
1414                               struct fb_info *info)
1415 {
1416         struct drm_fb_helper *fb_helper = info->par;
1417         struct drm_client_dev *client = &fb_helper->client;
1418         struct drm_mode_set *modeset;
1419         int ret = 0;
1420
1421         mutex_lock(&client->modeset_mutex);
1422         drm_modeset_lock_all(fb_helper->dev);
1423         drm_client_for_each_modeset(modeset, client) {
1424                 modeset->x = var->xoffset;
1425                 modeset->y = var->yoffset;
1426
1427                 if (modeset->num_connectors) {
1428                         ret = drm_mode_set_config_internal(modeset);
1429                         if (!ret) {
1430                                 info->var.xoffset = var->xoffset;
1431                                 info->var.yoffset = var->yoffset;
1432                         }
1433                 }
1434         }
1435         drm_modeset_unlock_all(fb_helper->dev);
1436         mutex_unlock(&client->modeset_mutex);
1437
1438         return ret;
1439 }
1440
1441 /**
1442  * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1443  * @var: updated screen information
1444  * @info: fbdev registered by the helper
1445  */
1446 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1447                               struct fb_info *info)
1448 {
1449         struct drm_fb_helper *fb_helper = info->par;
1450         struct drm_device *dev = fb_helper->dev;
1451         int ret;
1452
1453         if (oops_in_progress)
1454                 return -EBUSY;
1455
1456         mutex_lock(&fb_helper->lock);
1457         if (!drm_master_internal_acquire(dev)) {
1458                 ret = -EBUSY;
1459                 goto unlock;
1460         }
1461
1462         if (drm_drv_uses_atomic_modeset(dev))
1463                 ret = pan_display_atomic(var, info);
1464         else
1465                 ret = pan_display_legacy(var, info);
1466
1467         drm_master_internal_release(dev);
1468 unlock:
1469         mutex_unlock(&fb_helper->lock);
1470
1471         return ret;
1472 }
1473 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1474
1475 /*
1476  * Allocates the backing storage and sets up the fbdev info structure through
1477  * the ->fb_probe callback.
1478  */
1479 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1480                                          int preferred_bpp)
1481 {
1482         struct drm_client_dev *client = &fb_helper->client;
1483         struct drm_device *dev = fb_helper->dev;
1484         int ret = 0;
1485         int crtc_count = 0;
1486         struct drm_connector_list_iter conn_iter;
1487         struct drm_fb_helper_surface_size sizes;
1488         struct drm_connector *connector;
1489         struct drm_mode_set *mode_set;
1490         int best_depth = 0;
1491
1492         memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1493         sizes.surface_depth = 24;
1494         sizes.surface_bpp = 32;
1495         sizes.fb_width = (u32)-1;
1496         sizes.fb_height = (u32)-1;
1497
1498         /*
1499          * If driver picks 8 or 16 by default use that for both depth/bpp
1500          * to begin with
1501          */
1502         if (preferred_bpp != sizes.surface_bpp)
1503                 sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1504
1505         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1506         drm_client_for_each_connector_iter(connector, &conn_iter) {
1507                 struct drm_cmdline_mode *cmdline_mode;
1508
1509                 cmdline_mode = &connector->cmdline_mode;
1510
1511                 if (cmdline_mode->bpp_specified) {
1512                         switch (cmdline_mode->bpp) {
1513                         case 8:
1514                                 sizes.surface_depth = sizes.surface_bpp = 8;
1515                                 break;
1516                         case 15:
1517                                 sizes.surface_depth = 15;
1518                                 sizes.surface_bpp = 16;
1519                                 break;
1520                         case 16:
1521                                 sizes.surface_depth = sizes.surface_bpp = 16;
1522                                 break;
1523                         case 24:
1524                                 sizes.surface_depth = sizes.surface_bpp = 24;
1525                                 break;
1526                         case 32:
1527                                 sizes.surface_depth = 24;
1528                                 sizes.surface_bpp = 32;
1529                                 break;
1530                         }
1531                         break;
1532                 }
1533         }
1534         drm_connector_list_iter_end(&conn_iter);
1535
1536         /*
1537          * If we run into a situation where, for example, the primary plane
1538          * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1539          * 16) we need to scale down the depth of the sizes we request.
1540          */
1541         mutex_lock(&client->modeset_mutex);
1542         drm_client_for_each_modeset(mode_set, client) {
1543                 struct drm_crtc *crtc = mode_set->crtc;
1544                 struct drm_plane *plane = crtc->primary;
1545                 int j;
1546
1547                 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1548
1549                 for (j = 0; j < plane->format_count; j++) {
1550                         const struct drm_format_info *fmt;
1551
1552                         fmt = drm_format_info(plane->format_types[j]);
1553
1554                         /*
1555                          * Do not consider YUV or other complicated formats
1556                          * for framebuffers. This means only legacy formats
1557                          * are supported (fmt->depth is a legacy field) but
1558                          * the framebuffer emulation can only deal with such
1559                          * formats, specifically RGB/BGA formats.
1560                          */
1561                         if (fmt->depth == 0)
1562                                 continue;
1563
1564                         /* We found a perfect fit, great */
1565                         if (fmt->depth == sizes.surface_depth) {
1566                                 best_depth = fmt->depth;
1567                                 break;
1568                         }
1569
1570                         /* Skip depths above what we're looking for */
1571                         if (fmt->depth > sizes.surface_depth)
1572                                 continue;
1573
1574                         /* Best depth found so far */
1575                         if (fmt->depth > best_depth)
1576                                 best_depth = fmt->depth;
1577                 }
1578         }
1579         if (sizes.surface_depth != best_depth && best_depth) {
1580                 drm_info(dev, "requested bpp %d, scaled depth down to %d",
1581                          sizes.surface_bpp, best_depth);
1582                 sizes.surface_depth = best_depth;
1583         }
1584
1585         /* first up get a count of crtcs now in use and new min/maxes width/heights */
1586         crtc_count = 0;
1587         drm_client_for_each_modeset(mode_set, client) {
1588                 struct drm_display_mode *desired_mode;
1589                 int x, y, j;
1590                 /* in case of tile group, are we the last tile vert or horiz?
1591                  * If no tile group you are always the last one both vertically
1592                  * and horizontally
1593                  */
1594                 bool lastv = true, lasth = true;
1595
1596                 desired_mode = mode_set->mode;
1597
1598                 if (!desired_mode)
1599                         continue;
1600
1601                 crtc_count++;
1602
1603                 x = mode_set->x;
1604                 y = mode_set->y;
1605
1606                 sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1607                 sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1608
1609                 for (j = 0; j < mode_set->num_connectors; j++) {
1610                         struct drm_connector *connector = mode_set->connectors[j];
1611
1612                         if (connector->has_tile &&
1613                             desired_mode->hdisplay == connector->tile_h_size &&
1614                             desired_mode->vdisplay == connector->tile_v_size) {
1615                                 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1616                                 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1617                                 /* cloning to multiple tiles is just crazy-talk, so: */
1618                                 break;
1619                         }
1620                 }
1621
1622                 if (lasth)
1623                         sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1624                 if (lastv)
1625                         sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1626         }
1627         mutex_unlock(&client->modeset_mutex);
1628
1629         if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1630                 drm_info(dev, "Cannot find any crtc or sizes\n");
1631
1632                 /* First time: disable all crtc's.. */
1633                 if (!fb_helper->deferred_setup)
1634                         drm_client_modeset_commit(client);
1635                 return -EAGAIN;
1636         }
1637
1638         /* Handle our overallocation */
1639         sizes.surface_height *= drm_fbdev_overalloc;
1640         sizes.surface_height /= 100;
1641
1642         /* push down into drivers */
1643         ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1644         if (ret < 0)
1645                 return ret;
1646
1647         strcpy(fb_helper->fb->comm, "[fbcon]");
1648         return 0;
1649 }
1650
1651 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1652                                    uint32_t depth)
1653 {
1654         info->fix.type = FB_TYPE_PACKED_PIXELS;
1655         info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1656                 FB_VISUAL_TRUECOLOR;
1657         info->fix.mmio_start = 0;
1658         info->fix.mmio_len = 0;
1659         info->fix.type_aux = 0;
1660         info->fix.xpanstep = 1; /* doing it in hw */
1661         info->fix.ypanstep = 1; /* doing it in hw */
1662         info->fix.ywrapstep = 0;
1663         info->fix.accel = FB_ACCEL_NONE;
1664
1665         info->fix.line_length = pitch;
1666 }
1667
1668 static void drm_fb_helper_fill_var(struct fb_info *info,
1669                                    struct drm_fb_helper *fb_helper,
1670                                    uint32_t fb_width, uint32_t fb_height)
1671 {
1672         struct drm_framebuffer *fb = fb_helper->fb;
1673
1674         WARN_ON((drm_format_info_block_width(fb->format, 0) > 1) ||
1675                 (drm_format_info_block_height(fb->format, 0) > 1));
1676         info->pseudo_palette = fb_helper->pseudo_palette;
1677         info->var.xres_virtual = fb->width;
1678         info->var.yres_virtual = fb->height;
1679         info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1680         info->var.accel_flags = FB_ACCELF_TEXT;
1681         info->var.xoffset = 0;
1682         info->var.yoffset = 0;
1683         info->var.activate = FB_ACTIVATE_NOW;
1684
1685         drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
1686
1687         info->var.xres = fb_width;
1688         info->var.yres = fb_height;
1689 }
1690
1691 /**
1692  * drm_fb_helper_fill_info - initializes fbdev information
1693  * @info: fbdev instance to set up
1694  * @fb_helper: fb helper instance to use as template
1695  * @sizes: describes fbdev size and scanout surface size
1696  *
1697  * Sets up the variable and fixed fbdev metainformation from the given fb helper
1698  * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1699  *
1700  * Drivers should call this (or their equivalent setup code) from their
1701  * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1702  * backing storage framebuffer.
1703  */
1704 void drm_fb_helper_fill_info(struct fb_info *info,
1705                              struct drm_fb_helper *fb_helper,
1706                              struct drm_fb_helper_surface_size *sizes)
1707 {
1708         struct drm_framebuffer *fb = fb_helper->fb;
1709
1710         drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
1711         drm_fb_helper_fill_var(info, fb_helper,
1712                                sizes->fb_width, sizes->fb_height);
1713
1714         info->par = fb_helper;
1715         snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
1716                  fb_helper->dev->driver->name);
1717
1718 }
1719 EXPORT_SYMBOL(drm_fb_helper_fill_info);
1720
1721 /*
1722  * This is a continuation of drm_setup_crtcs() that sets up anything related
1723  * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1724  * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
1725  * So, any setup that touches those fields needs to be done here instead of in
1726  * drm_setup_crtcs().
1727  */
1728 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1729 {
1730         struct drm_client_dev *client = &fb_helper->client;
1731         struct drm_connector_list_iter conn_iter;
1732         struct fb_info *info = fb_helper->fbdev;
1733         unsigned int rotation, sw_rotations = 0;
1734         struct drm_connector *connector;
1735         struct drm_mode_set *modeset;
1736
1737         mutex_lock(&client->modeset_mutex);
1738         drm_client_for_each_modeset(modeset, client) {
1739                 if (!modeset->num_connectors)
1740                         continue;
1741
1742                 modeset->fb = fb_helper->fb;
1743
1744                 if (drm_client_rotation(modeset, &rotation))
1745                         /* Rotating in hardware, fbcon should not rotate */
1746                         sw_rotations |= DRM_MODE_ROTATE_0;
1747                 else
1748                         sw_rotations |= rotation;
1749         }
1750         mutex_unlock(&client->modeset_mutex);
1751
1752         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1753         drm_client_for_each_connector_iter(connector, &conn_iter) {
1754
1755                 /* use first connected connector for the physical dimensions */
1756                 if (connector->status == connector_status_connected) {
1757                         info->var.width = connector->display_info.width_mm;
1758                         info->var.height = connector->display_info.height_mm;
1759                         break;
1760                 }
1761         }
1762         drm_connector_list_iter_end(&conn_iter);
1763
1764         switch (sw_rotations) {
1765         case DRM_MODE_ROTATE_0:
1766                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1767                 break;
1768         case DRM_MODE_ROTATE_90:
1769                 info->fbcon_rotate_hint = FB_ROTATE_CCW;
1770                 break;
1771         case DRM_MODE_ROTATE_180:
1772                 info->fbcon_rotate_hint = FB_ROTATE_UD;
1773                 break;
1774         case DRM_MODE_ROTATE_270:
1775                 info->fbcon_rotate_hint = FB_ROTATE_CW;
1776                 break;
1777         default:
1778                 /*
1779                  * Multiple bits are set / multiple rotations requested
1780                  * fbcon cannot handle separate rotation settings per
1781                  * output, so fallback to unrotated.
1782                  */
1783                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1784         }
1785 }
1786
1787 /* Note: Drops fb_helper->lock before returning. */
1788 static int
1789 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
1790                                           int bpp_sel)
1791 {
1792         struct drm_device *dev = fb_helper->dev;
1793         struct fb_info *info;
1794         unsigned int width, height;
1795         int ret;
1796
1797         width = dev->mode_config.max_width;
1798         height = dev->mode_config.max_height;
1799
1800         drm_client_modeset_probe(&fb_helper->client, width, height);
1801         ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
1802         if (ret < 0) {
1803                 if (ret == -EAGAIN) {
1804                         fb_helper->preferred_bpp = bpp_sel;
1805                         fb_helper->deferred_setup = true;
1806                         ret = 0;
1807                 }
1808                 mutex_unlock(&fb_helper->lock);
1809
1810                 return ret;
1811         }
1812         drm_setup_crtcs_fb(fb_helper);
1813
1814         fb_helper->deferred_setup = false;
1815
1816         info = fb_helper->fbdev;
1817         info->var.pixclock = 0;
1818         /* Shamelessly allow physical address leaking to userspace */
1819 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1820         if (!drm_leak_fbdev_smem)
1821 #endif
1822                 /* don't leak any physical addresses to userspace */
1823                 info->flags |= FBINFO_HIDE_SMEM_START;
1824
1825         /* Need to drop locks to avoid recursive deadlock in
1826          * register_framebuffer. This is ok because the only thing left to do is
1827          * register the fbdev emulation instance in kernel_fb_helper_list. */
1828         mutex_unlock(&fb_helper->lock);
1829
1830         ret = register_framebuffer(info);
1831         if (ret < 0)
1832                 return ret;
1833
1834         drm_info(dev, "fb%d: %s frame buffer device\n",
1835                  info->node, info->fix.id);
1836
1837         mutex_lock(&kernel_fb_helper_lock);
1838         if (list_empty(&kernel_fb_helper_list))
1839                 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
1840
1841         list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
1842         mutex_unlock(&kernel_fb_helper_lock);
1843
1844         return 0;
1845 }
1846
1847 /**
1848  * drm_fb_helper_initial_config - setup a sane initial connector configuration
1849  * @fb_helper: fb_helper device struct
1850  * @bpp_sel: bpp value to use for the framebuffer configuration
1851  *
1852  * Scans the CRTCs and connectors and tries to put together an initial setup.
1853  * At the moment, this is a cloned configuration across all heads with
1854  * a new framebuffer object as the backing store.
1855  *
1856  * Note that this also registers the fbdev and so allows userspace to call into
1857  * the driver through the fbdev interfaces.
1858  *
1859  * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1860  * to let the driver allocate and initialize the fbdev info structure and the
1861  * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1862  * as a helper to setup simple default values for the fbdev info structure.
1863  *
1864  * HANG DEBUGGING:
1865  *
1866  * When you have fbcon support built-in or already loaded, this function will do
1867  * a full modeset to setup the fbdev console. Due to locking misdesign in the
1868  * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1869  * console_lock. Until console_unlock is called no dmesg lines will be sent out
1870  * to consoles, not even serial console. This means when your driver crashes,
1871  * you will see absolutely nothing else but a system stuck in this function,
1872  * with no further output. Any kind of printk() you place within your own driver
1873  * or in the drm core modeset code will also never show up.
1874  *
1875  * Standard debug practice is to run the fbcon setup without taking the
1876  * console_lock as a hack, to be able to see backtraces and crashes on the
1877  * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1878  * cmdline option.
1879  *
1880  * The other option is to just disable fbdev emulation since very likely the
1881  * first modeset from userspace will crash in the same way, and is even easier
1882  * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1883  * kernel cmdline option.
1884  *
1885  * RETURNS:
1886  * Zero if everything went ok, nonzero otherwise.
1887  */
1888 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
1889 {
1890         int ret;
1891
1892         if (!drm_fbdev_emulation)
1893                 return 0;
1894
1895         mutex_lock(&fb_helper->lock);
1896         ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
1897
1898         return ret;
1899 }
1900 EXPORT_SYMBOL(drm_fb_helper_initial_config);
1901
1902 /**
1903  * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1904  *                               probing all the outputs attached to the fb
1905  * @fb_helper: driver-allocated fbdev helper, can be NULL
1906  *
1907  * Scan the connectors attached to the fb_helper and try to put together a
1908  * setup after notification of a change in output configuration.
1909  *
1910  * Called at runtime, takes the mode config locks to be able to check/change the
1911  * modeset configuration. Must be run from process context (which usually means
1912  * either the output polling work or a work item launched from the driver's
1913  * hotplug interrupt).
1914  *
1915  * Note that drivers may call this even before calling
1916  * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1917  * for a race-free fbcon setup and will make sure that the fbdev emulation will
1918  * not miss any hotplug events.
1919  *
1920  * RETURNS:
1921  * 0 on success and a non-zero error code otherwise.
1922  */
1923 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1924 {
1925         int err = 0;
1926
1927         if (!drm_fbdev_emulation || !fb_helper)
1928                 return 0;
1929
1930         mutex_lock(&fb_helper->lock);
1931         if (fb_helper->deferred_setup) {
1932                 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
1933                                 fb_helper->preferred_bpp);
1934                 return err;
1935         }
1936
1937         if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
1938                 fb_helper->delayed_hotplug = true;
1939                 mutex_unlock(&fb_helper->lock);
1940                 return err;
1941         }
1942
1943         drm_master_internal_release(fb_helper->dev);
1944
1945         drm_dbg_kms(fb_helper->dev, "\n");
1946
1947         drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
1948         drm_setup_crtcs_fb(fb_helper);
1949         mutex_unlock(&fb_helper->lock);
1950
1951         drm_fb_helper_set_par(fb_helper->fbdev);
1952
1953         return 0;
1954 }
1955 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1956
1957 /**
1958  * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
1959  * @dev: DRM device
1960  *
1961  * This function can be used as the &drm_driver->lastclose callback for drivers
1962  * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
1963  */
1964 void drm_fb_helper_lastclose(struct drm_device *dev)
1965 {
1966         drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
1967 }
1968 EXPORT_SYMBOL(drm_fb_helper_lastclose);
1969
1970 /**
1971  * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
1972  *                                     helper for fbdev emulation
1973  * @dev: DRM device
1974  *
1975  * This function can be used as the
1976  * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
1977  * need to call drm_fb_helper_hotplug_event().
1978  */
1979 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
1980 {
1981         drm_fb_helper_hotplug_event(dev->fb_helper);
1982 }
1983 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
1984
1985 /* @user: 1=userspace, 0=fbcon */
1986 static int drm_fbdev_fb_open(struct fb_info *info, int user)
1987 {
1988         struct drm_fb_helper *fb_helper = info->par;
1989
1990         /* No need to take a ref for fbcon because it unbinds on unregister */
1991         if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
1992                 return -ENODEV;
1993
1994         return 0;
1995 }
1996
1997 static int drm_fbdev_fb_release(struct fb_info *info, int user)
1998 {
1999         struct drm_fb_helper *fb_helper = info->par;
2000
2001         if (user)
2002                 module_put(fb_helper->dev->driver->fops->owner);
2003
2004         return 0;
2005 }
2006
2007 static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
2008 {
2009         struct fb_info *fbi = fb_helper->fbdev;
2010         void *shadow = NULL;
2011
2012         if (!fb_helper->dev)
2013                 return;
2014
2015         if (fbi && fbi->fbdefio) {
2016                 fb_deferred_io_cleanup(fbi);
2017                 shadow = fbi->screen_buffer;
2018         }
2019
2020         drm_fb_helper_fini(fb_helper);
2021
2022         vfree(shadow);
2023
2024         drm_client_framebuffer_delete(fb_helper->buffer);
2025 }
2026
2027 static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
2028 {
2029         drm_fbdev_cleanup(fb_helper);
2030         drm_client_release(&fb_helper->client);
2031         kfree(fb_helper);
2032 }
2033
2034 /*
2035  * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
2036  * unregister_framebuffer() or fb_release().
2037  */
2038 static void drm_fbdev_fb_destroy(struct fb_info *info)
2039 {
2040         drm_fbdev_release(info->par);
2041 }
2042
2043 static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
2044 {
2045         struct drm_fb_helper *fb_helper = info->par;
2046
2047         if (fb_helper->dev->driver->gem_prime_mmap)
2048                 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
2049         else
2050                 return -ENODEV;
2051 }
2052
2053 static const struct fb_ops drm_fbdev_fb_ops = {
2054         .owner          = THIS_MODULE,
2055         DRM_FB_HELPER_DEFAULT_OPS,
2056         .fb_open        = drm_fbdev_fb_open,
2057         .fb_release     = drm_fbdev_fb_release,
2058         .fb_destroy     = drm_fbdev_fb_destroy,
2059         .fb_mmap        = drm_fbdev_fb_mmap,
2060         .fb_read        = drm_fb_helper_sys_read,
2061         .fb_write       = drm_fb_helper_sys_write,
2062         .fb_fillrect    = drm_fb_helper_sys_fillrect,
2063         .fb_copyarea    = drm_fb_helper_sys_copyarea,
2064         .fb_imageblit   = drm_fb_helper_sys_imageblit,
2065 };
2066
2067 static struct fb_deferred_io drm_fbdev_defio = {
2068         .delay          = HZ / 20,
2069         .deferred_io    = drm_fb_helper_deferred_io,
2070 };
2071
2072 /*
2073  * This function uses the client API to create a framebuffer backed by a dumb buffer.
2074  *
2075  * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
2076  * fb_copyarea, fb_imageblit.
2077  */
2078 static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
2079                                        struct drm_fb_helper_surface_size *sizes)
2080 {
2081         struct drm_client_dev *client = &fb_helper->client;
2082         struct drm_device *dev = fb_helper->dev;
2083         struct drm_client_buffer *buffer;
2084         struct drm_framebuffer *fb;
2085         struct fb_info *fbi;
2086         u32 format;
2087         void *vaddr;
2088
2089         drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
2090                     sizes->surface_width, sizes->surface_height,
2091                     sizes->surface_bpp);
2092
2093         format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
2094         buffer = drm_client_framebuffer_create(client, sizes->surface_width,
2095                                                sizes->surface_height, format);
2096         if (IS_ERR(buffer))
2097                 return PTR_ERR(buffer);
2098
2099         fb_helper->buffer = buffer;
2100         fb_helper->fb = buffer->fb;
2101         fb = buffer->fb;
2102
2103         fbi = drm_fb_helper_alloc_fbi(fb_helper);
2104         if (IS_ERR(fbi))
2105                 return PTR_ERR(fbi);
2106
2107         fbi->fbops = &drm_fbdev_fb_ops;
2108         fbi->screen_size = fb->height * fb->pitches[0];
2109         fbi->fix.smem_len = fbi->screen_size;
2110
2111         drm_fb_helper_fill_info(fbi, fb_helper, sizes);
2112
2113         if (drm_fbdev_use_shadow_fb(fb_helper)) {
2114                 fbi->screen_buffer = vzalloc(fbi->screen_size);
2115                 if (!fbi->screen_buffer)
2116                         return -ENOMEM;
2117
2118                 fbi->fbdefio = &drm_fbdev_defio;
2119
2120                 fb_deferred_io_init(fbi);
2121         } else {
2122                 /* buffer is mapped for HW framebuffer */
2123                 vaddr = drm_client_buffer_vmap(fb_helper->buffer);
2124                 if (IS_ERR(vaddr))
2125                         return PTR_ERR(vaddr);
2126
2127                 fbi->screen_buffer = vaddr;
2128                 /* Shamelessly leak the physical address to user-space */
2129 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2130                 if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
2131                         fbi->fix.smem_start =
2132                                 page_to_phys(virt_to_page(fbi->screen_buffer));
2133 #endif
2134         }
2135
2136         return 0;
2137 }
2138
2139 static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
2140         .fb_probe = drm_fb_helper_generic_probe,
2141 };
2142
2143 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
2144 {
2145         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2146
2147         if (fb_helper->fbdev)
2148                 /* drm_fbdev_fb_destroy() takes care of cleanup */
2149                 drm_fb_helper_unregister_fbi(fb_helper);
2150         else
2151                 drm_fbdev_release(fb_helper);
2152 }
2153
2154 static int drm_fbdev_client_restore(struct drm_client_dev *client)
2155 {
2156         drm_fb_helper_lastclose(client->dev);
2157
2158         return 0;
2159 }
2160
2161 static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
2162 {
2163         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2164         struct drm_device *dev = client->dev;
2165         int ret;
2166
2167         /* Setup is not retried if it has failed */
2168         if (!fb_helper->dev && fb_helper->funcs)
2169                 return 0;
2170
2171         if (dev->fb_helper)
2172                 return drm_fb_helper_hotplug_event(dev->fb_helper);
2173
2174         if (!dev->mode_config.num_connector) {
2175                 drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
2176                 return 0;
2177         }
2178
2179         drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
2180
2181         ret = drm_fb_helper_init(dev, fb_helper);
2182         if (ret)
2183                 goto err;
2184
2185         if (!drm_drv_uses_atomic_modeset(dev))
2186                 drm_helper_disable_unused_functions(dev);
2187
2188         ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
2189         if (ret)
2190                 goto err_cleanup;
2191
2192         return 0;
2193
2194 err_cleanup:
2195         drm_fbdev_cleanup(fb_helper);
2196 err:
2197         fb_helper->dev = NULL;
2198         fb_helper->fbdev = NULL;
2199
2200         drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
2201
2202         return ret;
2203 }
2204
2205 static const struct drm_client_funcs drm_fbdev_client_funcs = {
2206         .owner          = THIS_MODULE,
2207         .unregister     = drm_fbdev_client_unregister,
2208         .restore        = drm_fbdev_client_restore,
2209         .hotplug        = drm_fbdev_client_hotplug,
2210 };
2211
2212 /**
2213  * drm_fbdev_generic_setup() - Setup generic fbdev emulation
2214  * @dev: DRM device
2215  * @preferred_bpp: Preferred bits per pixel for the device.
2216  *                 @dev->mode_config.preferred_depth is used if this is zero.
2217  *
2218  * This function sets up generic fbdev emulation for drivers that supports
2219  * dumb buffers with a virtual address and that can be mmap'ed.
2220  * drm_fbdev_generic_setup() shall be called after the DRM driver registered
2221  * the new DRM device with drm_dev_register().
2222  *
2223  * Restore, hotplug events and teardown are all taken care of. Drivers that do
2224  * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
2225  * Simple drivers might use drm_mode_config_helper_suspend().
2226  *
2227  * Drivers that set the dirty callback on their framebuffer will get a shadow
2228  * fbdev buffer that is blitted onto the real buffer. This is done in order to
2229  * make deferred I/O work with all kinds of buffers. A shadow buffer can be
2230  * requested explicitly by setting struct drm_mode_config.prefer_shadow or
2231  * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is
2232  * required to use generic fbdev emulation with SHMEM helpers.
2233  *
2234  * This function is safe to call even when there are no connectors present.
2235  * Setup will be retried on the next hotplug event.
2236  *
2237  * The fbdev is destroyed by drm_dev_unregister().
2238  */
2239 void drm_fbdev_generic_setup(struct drm_device *dev,
2240                              unsigned int preferred_bpp)
2241 {
2242         struct drm_fb_helper *fb_helper;
2243         int ret;
2244
2245         drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
2246         drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
2247
2248         if (!drm_fbdev_emulation)
2249                 return;
2250
2251         fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
2252         if (!fb_helper) {
2253                 drm_err(dev, "Failed to allocate fb_helper\n");
2254                 return;
2255         }
2256
2257         ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
2258         if (ret) {
2259                 kfree(fb_helper);
2260                 drm_err(dev, "Failed to register client: %d\n", ret);
2261                 return;
2262         }
2263
2264         if (!preferred_bpp)
2265                 preferred_bpp = dev->mode_config.preferred_depth;
2266         if (!preferred_bpp)
2267                 preferred_bpp = 32;
2268         fb_helper->preferred_bpp = preferred_bpp;
2269
2270         ret = drm_fbdev_client_hotplug(&fb_helper->client);
2271         if (ret)
2272                 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
2273
2274         drm_client_register(&fb_helper->client);
2275 }
2276 EXPORT_SYMBOL(drm_fbdev_generic_setup);