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/pci.h>
  34 #include <linux/sysrq.h>
  35 #include <linux/vga_switcheroo.h>
  36
  37 #include <drm/drm_atomic.h>
  38 #include <drm/drm_drv.h>
  39 #include <drm/drm_fb_helper.h>
  40 #include <drm/drm_fourcc.h>
  41 #include <drm/drm_framebuffer.h>
  42 #include <drm/drm_modeset_helper_vtables.h>
  43 #include <drm/drm_print.h>
  44 #include <drm/drm_vblank.h>
  45
  46 #include "drm_internal.h"
  47
  48 static bool drm_fbdev_emulation = true;
  49 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
  50 MODULE_PARM_DESC(fbdev_emulation,
  51                  "Enable legacy fbdev emulation [default=true]");
  52
  53 static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
  54 module_param(drm_fbdev_overalloc, int, 0444);
  55 MODULE_PARM_DESC(drm_fbdev_overalloc,
  56                  "Overallocation of the fbdev buffer (%) [default="
  57                  __MODULE_STRING(CONFIG_DRM_FBDEV_OVERALLOC) "]");
  58
  59 /*
  60  * In order to keep user-space compatibility, we want in certain use-cases
  61  * to keep leaking the fbdev physical address to the user-space program
  62  * handling the fbdev buffer.
  63  * This is a bad habit essentially kept into closed source opengl driver
  64  * that should really be moved into open-source upstream projects instead
  65  * of using legacy physical addresses in user space to communicate with
  66  * other out-of-tree kernel modules.
  67  *
  68  * This module_param *should* be removed as soon as possible and be
  69  * considered as a broken and legacy behaviour from a modern fbdev device.
  70  */
  71 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
  72 static bool drm_leak_fbdev_smem;
  73 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
  74 MODULE_PARM_DESC(drm_leak_fbdev_smem,
  75                  "Allow unsafe leaking fbdev physical smem address [default=false]");
  76 #endif
  77
  78 static LIST_HEAD(kernel_fb_helper_list);
  79 static DEFINE_MUTEX(kernel_fb_helper_lock);
  80
  81 /**
  82  * DOC: fbdev helpers
  83  *
  84  * The fb helper functions are useful to provide an fbdev on top of a drm kernel
  85  * mode setting driver. They can be used mostly independently from the crtc
  86  * helper functions used by many drivers to implement the kernel mode setting
  87  * interfaces.
  88  *
  89  * Drivers that support a dumb buffer with a virtual address and mmap support,
  90  * should try out the generic fbdev emulation using drm_fbdev_generic_setup().
  91  * It will automatically set up deferred I/O if the driver requires a shadow
  92  * buffer.
  93  *
  94  * Existing fbdev implementations should restore the fbdev console by using
  95  * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback.
  96  * They should also notify the fb helper code from updates to the output
  97  * configuration by using drm_fb_helper_output_poll_changed() as their
  98  * &drm_mode_config_funcs.output_poll_changed callback. New implementations
  99  * of fbdev should be build on top of struct &drm_client_funcs, which handles
 100  * this automatically. Setting the old callbacks should be avoided.
 101  *
 102  * For suspend/resume consider using drm_mode_config_helper_suspend() and
 103  * drm_mode_config_helper_resume() which takes care of fbdev as well.
 104  *
 105  * All other functions exported by the fb helper library can be used to
 106  * implement the fbdev driver interface by the driver.
 107  *
 108  * It is possible, though perhaps somewhat tricky, to implement race-free
 109  * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
 110  * helper must be called first to initialize the minimum required to make
 111  * hotplug detection work. Drivers also need to make sure to properly set up
 112  * the &drm_mode_config.funcs member. After calling drm_kms_helper_poll_init()
 113  * it is safe to enable interrupts and start processing hotplug events. At the
 114  * same time, drivers should initialize all modeset objects such as CRTCs,
 115  * encoders and connectors. To finish up the fbdev helper initialization, the
 116  * drm_fb_helper_init() function is called. To probe for all attached displays
 117  * and set up an initial configuration using the detected hardware, drivers
 118  * should call drm_fb_helper_initial_config().
 119  *
 120  * If &drm_framebuffer_funcs.dirty is set, the
 121  * drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} functions will
 122  * accumulate changes and schedule &drm_fb_helper.dirty_work to run right
 123  * away. This worker then calls the dirty() function ensuring that it will
 124  * always run in process context since the fb_*() function could be running in
 125  * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io
 126  * callback it will also schedule dirty_work with the damage collected from the
 127  * mmap page writes.
 128  *
 129  * Deferred I/O is not compatible with SHMEM. Such drivers should request an
 130  * fbdev shadow buffer and call drm_fbdev_generic_setup() instead.
 131  */
 132
 133 static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc)
 134 {
 135         uint16_t *r_base, *g_base, *b_base;
 136
 137         if (crtc->funcs->gamma_set == NULL)
 138                 return;
 139
 140         r_base = crtc->gamma_store;
 141         g_base = r_base + crtc->gamma_size;
 142         b_base = g_base + crtc->gamma_size;
 143
 144         crtc->funcs->gamma_set(crtc, r_base, g_base, b_base,
 145                                crtc->gamma_size, NULL);
 146 }
 147
 148 /**
 149  * drm_fb_helper_debug_enter - implementation for &fb_ops.fb_debug_enter
 150  * @info: fbdev registered by the helper
 151  */
 152 int drm_fb_helper_debug_enter(struct fb_info *info)
 153 {
 154         struct drm_fb_helper *helper = info->par;
 155         const struct drm_crtc_helper_funcs *funcs;
 156         struct drm_mode_set *mode_set;
 157
 158         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 159                 mutex_lock(&helper->client.modeset_mutex);
 160                 drm_client_for_each_modeset(mode_set, &helper->client) {
 161                         if (!mode_set->crtc->enabled)
 162                                 continue;
 163
 164                         funcs = mode_set->crtc->helper_private;
 165                         if (funcs->mode_set_base_atomic == NULL)
 166                                 continue;
 167
 168                         if (drm_drv_uses_atomic_modeset(mode_set->crtc->dev))
 169                                 continue;
 170
 171                         funcs->mode_set_base_atomic(mode_set->crtc,
 172                                                     mode_set->fb,
 173                                                     mode_set->x,
 174                                                     mode_set->y,
 175                                                     ENTER_ATOMIC_MODE_SET);
 176                 }
 177                 mutex_unlock(&helper->client.modeset_mutex);
 178         }
 179
 180         return 0;
 181 }
 182 EXPORT_SYMBOL(drm_fb_helper_debug_enter);
 183
 184 /**
 185  * drm_fb_helper_debug_leave - implementation for &fb_ops.fb_debug_leave
 186  * @info: fbdev registered by the helper
 187  */
 188 int drm_fb_helper_debug_leave(struct fb_info *info)
 189 {
 190         struct drm_fb_helper *helper = info->par;
 191         struct drm_client_dev *client = &helper->client;
 192         struct drm_device *dev = helper->dev;
 193         struct drm_crtc *crtc;
 194         const struct drm_crtc_helper_funcs *funcs;
 195         struct drm_mode_set *mode_set;
 196         struct drm_framebuffer *fb;
 197
 198         mutex_lock(&client->modeset_mutex);
 199         drm_client_for_each_modeset(mode_set, client) {
 200                 crtc = mode_set->crtc;
 201                 if (drm_drv_uses_atomic_modeset(crtc->dev))
 202                         continue;
 203
 204                 funcs = crtc->helper_private;
 205                 fb = crtc->primary->fb;
 206
 207                 if (!crtc->enabled)
 208                         continue;
 209
 210                 if (!fb) {
 211                         drm_err(dev, "no fb to restore?\n");
 212                         continue;
 213                 }
 214
 215                 if (funcs->mode_set_base_atomic == NULL)
 216                         continue;
 217
 218                 drm_fb_helper_restore_lut_atomic(mode_set->crtc);
 219                 funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x,
 220                                             crtc->y, LEAVE_ATOMIC_MODE_SET);
 221         }
 222         mutex_unlock(&client->modeset_mutex);
 223
 224         return 0;
 225 }
 226 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 227
 228 static int
 229 __drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
 230                                             bool force)
 231 {
 232         bool do_delayed;
 233         int ret;
 234
 235         if (!drm_fbdev_emulation || !fb_helper)
 236                 return -ENODEV;
 237
 238         if (READ_ONCE(fb_helper->deferred_setup))
 239                 return 0;
 240
 241         mutex_lock(&fb_helper->lock);
 242         if (force) {
 243                 /*
 244                  * Yes this is the _locked version which expects the master lock
 245                  * to be held. But for forced restores we're intentionally
 246                  * racing here, see drm_fb_helper_set_par().
 247                  */
 248                 ret = drm_client_modeset_commit_locked(&fb_helper->client);
 249         } else {
 250                 ret = drm_client_modeset_commit(&fb_helper->client);
 251         }
 252
 253         do_delayed = fb_helper->delayed_hotplug;
 254         if (do_delayed)
 255                 fb_helper->delayed_hotplug = false;
 256         mutex_unlock(&fb_helper->lock);
 257
 258         if (do_delayed)
 259                 drm_fb_helper_hotplug_event(fb_helper);
 260
 261         return ret;
 262 }
 263
 264 /**
 265  * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
 266  * @fb_helper: driver-allocated fbdev helper, can be NULL
 267  *
 268  * This should be called from driver's drm &drm_driver.lastclose callback
 269  * when implementing an fbcon on top of kms using this helper. This ensures that
 270  * the user isn't greeted with a black screen when e.g. X dies.
 271  *
 272  * RETURNS:
 273  * Zero if everything went ok, negative error code otherwise.
 274  */
 275 int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 276 {
 277         return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
 278 }
 279 EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 280
 281 #ifdef CONFIG_MAGIC_SYSRQ
 282 /* emergency restore, don't bother with error reporting */
 283 static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 284 {
 285         struct drm_fb_helper *helper;
 286
 287         mutex_lock(&kernel_fb_helper_lock);
 288         list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 289                 struct drm_device *dev = helper->dev;
 290
 291                 if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 292                         continue;
 293
 294                 mutex_lock(&helper->lock);
 295                 drm_client_modeset_commit_locked(&helper->client);
 296                 mutex_unlock(&helper->lock);
 297         }
 298         mutex_unlock(&kernel_fb_helper_lock);
 299 }
 300
 301 static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
 302
 303 static void drm_fb_helper_sysrq(int dummy1)
 304 {
 305         schedule_work(&drm_fb_helper_restore_work);
 306 }
 307
 308 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 309         .handler = drm_fb_helper_sysrq,
 310         .help_msg = "force-fb(v)",
 311         .action_msg = "Restore framebuffer console",
 312 };
 313 #else
 314 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
 315 #endif
 316
 317 static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 318 {
 319         struct drm_fb_helper *fb_helper = info->par;
 320
 321         mutex_lock(&fb_helper->lock);
 322         drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
 323         mutex_unlock(&fb_helper->lock);
 324 }
 325
 326 /**
 327  * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
 328  * @blank: desired blanking state
 329  * @info: fbdev registered by the helper
 330  */
 331 int drm_fb_helper_blank(int blank, struct fb_info *info)
 332 {
 333         if (oops_in_progress)
 334                 return -EBUSY;
 335
 336         switch (blank) {
 337         /* Display: On; HSync: On, VSync: On */
 338         case FB_BLANK_UNBLANK:
 339                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
 340                 break;
 341         /* Display: Off; HSync: On, VSync: On */
 342         case FB_BLANK_NORMAL:
 343                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 344                 break;
 345         /* Display: Off; HSync: Off, VSync: On */
 346         case FB_BLANK_HSYNC_SUSPEND:
 347                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 348                 break;
 349         /* Display: Off; HSync: On, VSync: Off */
 350         case FB_BLANK_VSYNC_SUSPEND:
 351                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
 352                 break;
 353         /* Display: Off; HSync: Off, VSync: Off */
 354         case FB_BLANK_POWERDOWN:
 355                 drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
 356                 break;
 357         }
 358         return 0;
 359 }
 360 EXPORT_SYMBOL(drm_fb_helper_blank);
 361
 362 static void drm_fb_helper_resume_worker(struct work_struct *work)
 363 {
 364         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 365                                                     resume_work);
 366
 367         console_lock();
 368         fb_set_suspend(helper->info, 0);
 369         console_unlock();
 370 }
 371
 372 static void drm_fb_helper_fb_dirty(struct drm_fb_helper *helper)
 373 {
 374         struct drm_device *dev = helper->dev;
 375         struct drm_clip_rect *clip = &helper->damage_clip;
 376         struct drm_clip_rect clip_copy;
 377         unsigned long flags;
 378         int ret;
 379
 380         if (drm_WARN_ON_ONCE(dev, !helper->funcs->fb_dirty))
 381                 return;
 382
 383         spin_lock_irqsave(&helper->damage_lock, flags);
 384         clip_copy = *clip;
 385         clip->x1 = clip->y1 = ~0;
 386         clip->x2 = clip->y2 = 0;
 387         spin_unlock_irqrestore(&helper->damage_lock, flags);
 388
 389         ret = helper->funcs->fb_dirty(helper, &clip_copy);
 390         if (ret)
 391                 goto err;
 392
 393         return;
 394
 395 err:
 396         /*
 397          * Restore damage clip rectangle on errors. The next run
 398          * of the damage worker will perform the update.
 399          */
 400         spin_lock_irqsave(&helper->damage_lock, flags);
 401         clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
 402         clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
 403         clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
 404         clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
 405         spin_unlock_irqrestore(&helper->damage_lock, flags);
 406 }
 407
 408 static void drm_fb_helper_damage_work(struct work_struct *work)
 409 {
 410         struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, damage_work);
 411
 412         drm_fb_helper_fb_dirty(helper);
 413 }
 414
 415 /**
 416  * drm_fb_helper_prepare - setup a drm_fb_helper structure
 417  * @dev: DRM device
 418  * @helper: driver-allocated fbdev helper structure to set up
 419  * @preferred_bpp: Preferred bits per pixel for the device.
 420  * @funcs: pointer to structure of functions associate with this helper
 421  *
 422  * Sets up the bare minimum to make the framebuffer helper usable. This is
 423  * useful to implement race-free initialization of the polling helpers.
 424  */
 425 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 426                            unsigned int preferred_bpp,
 427                            const struct drm_fb_helper_funcs *funcs)
 428 {
 429         /*
 430          * Pick a preferred bpp of 32 if no value has been given. This
 431          * will select XRGB8888 for the framebuffer formats. All drivers
 432          * have to support XRGB8888 for backwards compatibility with legacy
 433          * userspace, so it's the safe choice here.
 434          *
 435          * TODO: Replace struct drm_mode_config.preferred_depth and this
 436          *       bpp value with a preferred format that is given as struct
 437          *       drm_format_info. Then derive all other values from the
 438          *       format.
 439          */
 440         if (!preferred_bpp)
 441                 preferred_bpp = 32;
 442
 443         INIT_LIST_HEAD(&helper->kernel_fb_list);
 444         spin_lock_init(&helper->damage_lock);
 445         INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 446         INIT_WORK(&helper->damage_work, drm_fb_helper_damage_work);
 447         helper->damage_clip.x1 = helper->damage_clip.y1 = ~0;
 448         mutex_init(&helper->lock);
 449         helper->funcs = funcs;
 450         helper->dev = dev;
 451         helper->preferred_bpp = preferred_bpp;
 452 }
 453 EXPORT_SYMBOL(drm_fb_helper_prepare);
 454
 455 /**
 456  * drm_fb_helper_unprepare - clean up a drm_fb_helper structure
 457  * @fb_helper: driver-allocated fbdev helper structure to set up
 458  *
 459  * Cleans up the framebuffer helper. Inverse of drm_fb_helper_prepare().
 460  */
 461 void drm_fb_helper_unprepare(struct drm_fb_helper *fb_helper)
 462 {
 463         mutex_destroy(&fb_helper->lock);
 464 }
 465 EXPORT_SYMBOL(drm_fb_helper_unprepare);
 466
 467 /**
 468  * drm_fb_helper_init - initialize a &struct drm_fb_helper
 469  * @dev: drm device
 470  * @fb_helper: driver-allocated fbdev helper structure to initialize
 471  *
 472  * This allocates the structures for the fbdev helper with the given limits.
 473  * Note that this won't yet touch the hardware (through the driver interfaces)
 474  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 475  * to allow driver writes more control over the exact init sequence.
 476  *
 477  * Drivers must call drm_fb_helper_prepare() before calling this function.
 478  *
 479  * RETURNS:
 480  * Zero if everything went ok, nonzero otherwise.
 481  */
 482 int drm_fb_helper_init(struct drm_device *dev,
 483                        struct drm_fb_helper *fb_helper)
 484 {
 485         int ret;
 486
 487         /*
 488          * If this is not the generic fbdev client, initialize a drm_client
 489          * without callbacks so we can use the modesets.
 490          */
 491         if (!fb_helper->client.funcs) {
 492                 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
 493                 if (ret)
 494                         return ret;
 495         }
 496
 497         dev->fb_helper = fb_helper;
 498
 499         return 0;
 500 }
 501 EXPORT_SYMBOL(drm_fb_helper_init);
 502
 503 /**
 504  * drm_fb_helper_alloc_info - allocate fb_info and some of its members
 505  * @fb_helper: driver-allocated fbdev helper
 506  *
 507  * A helper to alloc fb_info and the member cmap. Called by the driver
 508  * within the fb_probe fb_helper callback function. Drivers do not
 509  * need to release the allocated fb_info structure themselves, this is
 510  * automatically done when calling drm_fb_helper_fini().
 511  *
 512  * RETURNS:
 513  * fb_info pointer if things went okay, pointer containing error code
 514  * otherwise
 515  */
 516 struct fb_info *drm_fb_helper_alloc_info(struct drm_fb_helper *fb_helper)
 517 {
 518         struct device *dev = fb_helper->dev->dev;
 519         struct fb_info *info;
 520         int ret;
 521
 522         info = framebuffer_alloc(0, dev);
 523         if (!info)
 524                 return ERR_PTR(-ENOMEM);
 525
 526         ret = fb_alloc_cmap(&info->cmap, 256, 0);
 527         if (ret)
 528                 goto err_release;
 529
 530         fb_helper->info = info;
 531         info->skip_vt_switch = true;
 532
 533         return info;
 534
 535 err_release:
 536         framebuffer_release(info);
 537         return ERR_PTR(ret);
 538 }
 539 EXPORT_SYMBOL(drm_fb_helper_alloc_info);
 540
 541 /**
 542  * drm_fb_helper_unregister_info - unregister fb_info framebuffer device
 543  * @fb_helper: driver-allocated fbdev helper, can be NULL
 544  *
 545  * A wrapper around unregister_framebuffer, to release the fb_info
 546  * framebuffer device. This must be called before releasing all resources for
 547  * @fb_helper by calling drm_fb_helper_fini().
 548  */
 549 void drm_fb_helper_unregister_info(struct drm_fb_helper *fb_helper)
 550 {
 551         if (fb_helper && fb_helper->info)
 552                 unregister_framebuffer(fb_helper->info);
 553 }
 554 EXPORT_SYMBOL(drm_fb_helper_unregister_info);
 555
 556 /**
 557  * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 558  * @fb_helper: driver-allocated fbdev helper, can be NULL
 559  *
 560  * This cleans up all remaining resources associated with @fb_helper.
 561  */
 562 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 563 {
 564         struct fb_info *info;
 565
 566         if (!fb_helper)
 567                 return;
 568
 569         fb_helper->dev->fb_helper = NULL;
 570
 571         if (!drm_fbdev_emulation)
 572                 return;
 573
 574         cancel_work_sync(&fb_helper->resume_work);
 575         cancel_work_sync(&fb_helper->damage_work);
 576
 577         info = fb_helper->info;
 578         if (info) {
 579                 if (info->cmap.len)
 580                         fb_dealloc_cmap(&info->cmap);
 581                 framebuffer_release(info);
 582         }
 583         fb_helper->info = NULL;
 584
 585         mutex_lock(&kernel_fb_helper_lock);
 586         if (!list_empty(&fb_helper->kernel_fb_list)) {
 587                 list_del(&fb_helper->kernel_fb_list);
 588                 if (list_empty(&kernel_fb_helper_list))
 589                         unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 590         }
 591         mutex_unlock(&kernel_fb_helper_lock);
 592
 593         if (!fb_helper->client.funcs)
 594                 drm_client_release(&fb_helper->client);
 595 }
 596 EXPORT_SYMBOL(drm_fb_helper_fini);
 597
 598 static void drm_fb_helper_add_damage_clip(struct drm_fb_helper *helper, u32 x, u32 y,
 599                                           u32 width, u32 height)
 600 {
 601         struct drm_clip_rect *clip = &helper->damage_clip;
 602         unsigned long flags;
 603
 604         spin_lock_irqsave(&helper->damage_lock, flags);
 605         clip->x1 = min_t(u32, clip->x1, x);
 606         clip->y1 = min_t(u32, clip->y1, y);
 607         clip->x2 = max_t(u32, clip->x2, x + width);
 608         clip->y2 = max_t(u32, clip->y2, y + height);
 609         spin_unlock_irqrestore(&helper->damage_lock, flags);
 610 }
 611
 612 static void drm_fb_helper_damage(struct drm_fb_helper *helper, u32 x, u32 y,
 613                                  u32 width, u32 height)
 614 {
 615         drm_fb_helper_add_damage_clip(helper, x, y, width, height);
 616
 617         schedule_work(&helper->damage_work);
 618 }
 619
 620 /*
 621  * Convert memory region into area of scanlines and pixels per
 622  * scanline. The parameters off and len must not reach beyond
 623  * the end of the framebuffer.
 624  */
 625 static void drm_fb_helper_memory_range_to_clip(struct fb_info *info, off_t off, size_t len,
 626                                                struct drm_rect *clip)
 627 {
 628         off_t end = off + len;
 629         u32 x1 = 0;
 630         u32 y1 = off / info->fix.line_length;
 631         u32 x2 = info->var.xres;
 632         u32 y2 = DIV_ROUND_UP(end, info->fix.line_length);
 633
 634         if ((y2 - y1) == 1) {
 635                 /*
 636                  * We've only written to a single scanline. Try to reduce
 637                  * the number of horizontal pixels that need an update.
 638                  */
 639                 off_t bit_off = (off % info->fix.line_length) * 8;
 640                 off_t bit_end = (end % info->fix.line_length) * 8;
 641
 642                 x1 = bit_off / info->var.bits_per_pixel;
 643                 x2 = DIV_ROUND_UP(bit_end, info->var.bits_per_pixel);
 644         }
 645
 646         drm_rect_init(clip, x1, y1, x2 - x1, y2 - y1);
 647 }
 648
 649 /**
 650  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 651  * @info: fb_info struct pointer
 652  * @pagereflist: list of mmap framebuffer pages that have to be flushed
 653  *
 654  * This function is used as the &fb_deferred_io.deferred_io
 655  * callback function for flushing the fbdev mmap writes.
 656  */
 657 void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist)
 658 {
 659         struct drm_fb_helper *helper = info->par;
 660         unsigned long start, end, min_off, max_off;
 661         struct fb_deferred_io_pageref *pageref;
 662         struct drm_rect damage_area;
 663
 664         min_off = ULONG_MAX;
 665         max_off = 0;
 666         list_for_each_entry(pageref, pagereflist, list) {
 667                 start = pageref->offset;
 668                 end = start + PAGE_SIZE;
 669                 min_off = min(min_off, start);
 670                 max_off = max(max_off, end);
 671         }
 672
 673         /*
 674          * As we can only track pages, we might reach beyond the end
 675          * of the screen and account for non-existing scanlines. Hence,
 676          * keep the covered memory area within the screen buffer.
 677          */
 678         max_off = min(max_off, info->screen_size);
 679
 680         if (min_off < max_off) {
 681                 drm_fb_helper_memory_range_to_clip(info, min_off, max_off - min_off, &damage_area);
 682                 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
 683                                      drm_rect_width(&damage_area),
 684                                      drm_rect_height(&damage_area));
 685         }
 686 }
 687 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 688
 689 typedef ssize_t (*drm_fb_helper_read_screen)(struct fb_info *info, char __user *buf,
 690                                              size_t count, loff_t pos);
 691
 692 static ssize_t __drm_fb_helper_read(struct fb_info *info, char __user *buf, size_t count,
 693                                     loff_t *ppos, drm_fb_helper_read_screen read_screen)
 694 {
 695         loff_t pos = *ppos;
 696         size_t total_size;
 697         ssize_t ret;
 698
 699         if (info->screen_size)
 700                 total_size = info->screen_size;
 701         else
 702                 total_size = info->fix.smem_len;
 703
 704         if (pos >= total_size)
 705                 return 0;
 706         if (count >= total_size)
 707                 count = total_size;
 708         if (total_size - count < pos)
 709                 count = total_size - pos;
 710
 711         if (info->fbops->fb_sync)
 712                 info->fbops->fb_sync(info);
 713
 714         ret = read_screen(info, buf, count, pos);
 715         if (ret > 0)
 716                 *ppos += ret;
 717
 718         return ret;
 719 }
 720
 721 typedef ssize_t (*drm_fb_helper_write_screen)(struct fb_info *info, const char __user *buf,
 722                                               size_t count, loff_t pos);
 723
 724 static ssize_t __drm_fb_helper_write(struct fb_info *info, const char __user *buf, size_t count,
 725                                      loff_t *ppos, drm_fb_helper_write_screen write_screen)
 726 {
 727         loff_t pos = *ppos;
 728         size_t total_size;
 729         ssize_t ret;
 730         int err = 0;
 731
 732         if (info->screen_size)
 733                 total_size = info->screen_size;
 734         else
 735                 total_size = info->fix.smem_len;
 736
 737         if (pos > total_size)
 738                 return -EFBIG;
 739         if (count > total_size) {
 740                 err = -EFBIG;
 741                 count = total_size;
 742         }
 743         if (total_size - count < pos) {
 744                 if (!err)
 745                         err = -ENOSPC;
 746                 count = total_size - pos;
 747         }
 748
 749         if (info->fbops->fb_sync)
 750                 info->fbops->fb_sync(info);
 751
 752         /*
 753          * Copy to framebuffer even if we already logged an error. Emulates
 754          * the behavior of the original fbdev implementation.
 755          */
 756         ret = write_screen(info, buf, count, pos);
 757         if (ret < 0)
 758                 return ret; /* return last error, if any */
 759         else if (!ret)
 760                 return err; /* return previous error, if any */
 761
 762         *ppos += ret;
 763
 764         return ret;
 765 }
 766
 767 static ssize_t drm_fb_helper_read_screen_buffer(struct fb_info *info, char __user *buf,
 768                                                 size_t count, loff_t pos)
 769 {
 770         const char *src = info->screen_buffer + pos;
 771
 772         if (copy_to_user(buf, src, count))
 773                 return -EFAULT;
 774
 775         return count;
 776 }
 777
 778 /**
 779  * drm_fb_helper_sys_read - Implements struct &fb_ops.fb_read for system memory
 780  * @info: fb_info struct pointer
 781  * @buf: userspace buffer to read from framebuffer memory
 782  * @count: number of bytes to read from framebuffer memory
 783  * @ppos: read offset within framebuffer memory
 784  *
 785  * Returns:
 786  * The number of bytes read on success, or an error code otherwise.
 787  */
 788 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 789                                size_t count, loff_t *ppos)
 790 {
 791         return __drm_fb_helper_read(info, buf, count, ppos, drm_fb_helper_read_screen_buffer);
 792 }
 793 EXPORT_SYMBOL(drm_fb_helper_sys_read);
 794
 795 static ssize_t drm_fb_helper_write_screen_buffer(struct fb_info *info, const char __user *buf,
 796                                                  size_t count, loff_t pos)
 797 {
 798         char *dst = info->screen_buffer + pos;
 799
 800         if (copy_from_user(dst, buf, count))
 801                 return -EFAULT;
 802
 803         return count;
 804 }
 805
 806 /**
 807  * drm_fb_helper_sys_write - Implements struct &fb_ops.fb_write for system memory
 808  * @info: fb_info struct pointer
 809  * @buf: userspace buffer to write to framebuffer memory
 810  * @count: number of bytes to write to framebuffer memory
 811  * @ppos: write offset within framebuffer memory
 812  *
 813  * Returns:
 814  * The number of bytes written on success, or an error code otherwise.
 815  */
 816 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 817                                 size_t count, loff_t *ppos)
 818 {
 819         struct drm_fb_helper *helper = info->par;
 820         loff_t pos = *ppos;
 821         ssize_t ret;
 822         struct drm_rect damage_area;
 823
 824         ret = __drm_fb_helper_write(info, buf, count, ppos, drm_fb_helper_write_screen_buffer);
 825         if (ret <= 0)
 826                 return ret;
 827
 828         if (helper->funcs->fb_dirty) {
 829                 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
 830                 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
 831                                      drm_rect_width(&damage_area),
 832                                      drm_rect_height(&damage_area));
 833         }
 834
 835         return ret;
 836 }
 837 EXPORT_SYMBOL(drm_fb_helper_sys_write);
 838
 839 /**
 840  * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
 841  * @info: fbdev registered by the helper
 842  * @rect: info about rectangle to fill
 843  *
 844  * A wrapper around sys_fillrect implemented by fbdev core
 845  */
 846 void drm_fb_helper_sys_fillrect(struct fb_info *info,
 847                                 const struct fb_fillrect *rect)
 848 {
 849         struct drm_fb_helper *helper = info->par;
 850
 851         sys_fillrect(info, rect);
 852
 853         if (helper->funcs->fb_dirty)
 854                 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
 855 }
 856 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 857
 858 /**
 859  * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
 860  * @info: fbdev registered by the helper
 861  * @area: info about area to copy
 862  *
 863  * A wrapper around sys_copyarea implemented by fbdev core
 864  */
 865 void drm_fb_helper_sys_copyarea(struct fb_info *info,
 866                                 const struct fb_copyarea *area)
 867 {
 868         struct drm_fb_helper *helper = info->par;
 869
 870         sys_copyarea(info, area);
 871
 872         if (helper->funcs->fb_dirty)
 873                 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
 874 }
 875 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 876
 877 /**
 878  * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
 879  * @info: fbdev registered by the helper
 880  * @image: info about image to blit
 881  *
 882  * A wrapper around sys_imageblit implemented by fbdev core
 883  */
 884 void drm_fb_helper_sys_imageblit(struct fb_info *info,
 885                                  const struct fb_image *image)
 886 {
 887         struct drm_fb_helper *helper = info->par;
 888
 889         sys_imageblit(info, image);
 890
 891         if (helper->funcs->fb_dirty)
 892                 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
 893 }
 894 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 895
 896 static ssize_t fb_read_screen_base(struct fb_info *info, char __user *buf, size_t count,
 897                                    loff_t pos)
 898 {
 899         const char __iomem *src = info->screen_base + pos;
 900         size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
 901         ssize_t ret = 0;
 902         int err = 0;
 903         char *tmp;
 904
 905         tmp = kmalloc(alloc_size, GFP_KERNEL);
 906         if (!tmp)
 907                 return -ENOMEM;
 908
 909         while (count) {
 910                 size_t c = min_t(size_t, count, alloc_size);
 911
 912                 memcpy_fromio(tmp, src, c);
 913                 if (copy_to_user(buf, tmp, c)) {
 914                         err = -EFAULT;
 915                         break;
 916                 }
 917
 918                 src += c;
 919                 buf += c;
 920                 ret += c;
 921                 count -= c;
 922         }
 923
 924         kfree(tmp);
 925
 926         return ret ? ret : err;
 927 }
 928
 929 /**
 930  * drm_fb_helper_cfb_read - Implements struct &fb_ops.fb_read for I/O memory
 931  * @info: fb_info struct pointer
 932  * @buf: userspace buffer to read from framebuffer memory
 933  * @count: number of bytes to read from framebuffer memory
 934  * @ppos: read offset within framebuffer memory
 935  *
 936  * Returns:
 937  * The number of bytes read on success, or an error code otherwise.
 938  */
 939 ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
 940                                size_t count, loff_t *ppos)
 941 {
 942         return __drm_fb_helper_read(info, buf, count, ppos, fb_read_screen_base);
 943 }
 944 EXPORT_SYMBOL(drm_fb_helper_cfb_read);
 945
 946 static ssize_t fb_write_screen_base(struct fb_info *info, const char __user *buf, size_t count,
 947                                     loff_t pos)
 948 {
 949         char __iomem *dst = info->screen_base + pos;
 950         size_t alloc_size = min_t(size_t, count, PAGE_SIZE);
 951         ssize_t ret = 0;
 952         int err = 0;
 953         u8 *tmp;
 954
 955         tmp = kmalloc(alloc_size, GFP_KERNEL);
 956         if (!tmp)
 957                 return -ENOMEM;
 958
 959         while (count) {
 960                 size_t c = min_t(size_t, count, alloc_size);
 961
 962                 if (copy_from_user(tmp, buf, c)) {
 963                         err = -EFAULT;
 964                         break;
 965                 }
 966                 memcpy_toio(dst, tmp, c);
 967
 968                 dst += c;
 969                 buf += c;
 970                 ret += c;
 971                 count -= c;
 972         }
 973
 974         kfree(tmp);
 975
 976         return ret ? ret : err;
 977 }
 978
 979 /**
 980  * drm_fb_helper_cfb_write - Implements struct &fb_ops.fb_write for I/O memory
 981  * @info: fb_info struct pointer
 982  * @buf: userspace buffer to write to framebuffer memory
 983  * @count: number of bytes to write to framebuffer memory
 984  * @ppos: write offset within framebuffer memory
 985  *
 986  * Returns:
 987  * The number of bytes written on success, or an error code otherwise.
 988  */
 989 ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
 990                                 size_t count, loff_t *ppos)
 991 {
 992         struct drm_fb_helper *helper = info->par;
 993         loff_t pos = *ppos;
 994         ssize_t ret;
 995         struct drm_rect damage_area;
 996
 997         ret = __drm_fb_helper_write(info, buf, count, ppos, fb_write_screen_base);
 998         if (ret <= 0)
 999                 return ret;
1000
1001         if (helper->funcs->fb_dirty) {
1002                 drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
1003                 drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
1004                                      drm_rect_width(&damage_area),
1005                                      drm_rect_height(&damage_area));
1006         }
1007
1008         return ret;
1009 }
1010 EXPORT_SYMBOL(drm_fb_helper_cfb_write);
1011
1012 /**
1013  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
1014  * @info: fbdev registered by the helper
1015  * @rect: info about rectangle to fill
1016  *
1017  * A wrapper around cfb_fillrect implemented by fbdev core
1018  */
1019 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
1020                                 const struct fb_fillrect *rect)
1021 {
1022         struct drm_fb_helper *helper = info->par;
1023
1024         cfb_fillrect(info, rect);
1025
1026         if (helper->funcs->fb_dirty)
1027                 drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
1028 }
1029 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
1030
1031 /**
1032  * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
1033  * @info: fbdev registered by the helper
1034  * @area: info about area to copy
1035  *
1036  * A wrapper around cfb_copyarea implemented by fbdev core
1037  */
1038 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
1039                                 const struct fb_copyarea *area)
1040 {
1041         struct drm_fb_helper *helper = info->par;
1042
1043         cfb_copyarea(info, area);
1044
1045         if (helper->funcs->fb_dirty)
1046                 drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
1047 }
1048 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
1049
1050 /**
1051  * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
1052  * @info: fbdev registered by the helper
1053  * @image: info about image to blit
1054  *
1055  * A wrapper around cfb_imageblit implemented by fbdev core
1056  */
1057 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
1058                                  const struct fb_image *image)
1059 {
1060         struct drm_fb_helper *helper = info->par;
1061
1062         cfb_imageblit(info, image);
1063
1064         if (helper->funcs->fb_dirty)
1065                 drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
1066 }
1067 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
1068
1069 /**
1070  * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
1071  * @fb_helper: driver-allocated fbdev helper, can be NULL
1072  * @suspend: whether to suspend or resume
1073  *
1074  * A wrapper around fb_set_suspend implemented by fbdev core.
1075  * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
1076  * the lock yourself
1077  */
1078 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
1079 {
1080         if (fb_helper && fb_helper->info)
1081                 fb_set_suspend(fb_helper->info, suspend);
1082 }
1083 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
1084
1085 /**
1086  * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
1087  *                                      takes the console lock
1088  * @fb_helper: driver-allocated fbdev helper, can be NULL
1089  * @suspend: whether to suspend or resume
1090  *
1091  * A wrapper around fb_set_suspend() that takes the console lock. If the lock
1092  * isn't available on resume, a worker is tasked with waiting for the lock
1093  * to become available. The console lock can be pretty contented on resume
1094  * due to all the printk activity.
1095  *
1096  * This function can be called multiple times with the same state since
1097  * &fb_info.state is checked to see if fbdev is running or not before locking.
1098  *
1099  * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
1100  */
1101 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
1102                                         bool suspend)
1103 {
1104         if (!fb_helper || !fb_helper->info)
1105                 return;
1106
1107         /* make sure there's no pending/ongoing resume */
1108         flush_work(&fb_helper->resume_work);
1109
1110         if (suspend) {
1111                 if (fb_helper->info->state != FBINFO_STATE_RUNNING)
1112                         return;
1113
1114                 console_lock();
1115
1116         } else {
1117                 if (fb_helper->info->state == FBINFO_STATE_RUNNING)
1118                         return;
1119
1120                 if (!console_trylock()) {
1121                         schedule_work(&fb_helper->resume_work);
1122                         return;
1123                 }
1124         }
1125
1126         fb_set_suspend(fb_helper->info, suspend);
1127         console_unlock();
1128 }
1129 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
1130
1131 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
1132 {
1133         u32 *palette = (u32 *)info->pseudo_palette;
1134         int i;
1135
1136         if (cmap->start + cmap->len > 16)
1137                 return -EINVAL;
1138
1139         for (i = 0; i < cmap->len; ++i) {
1140                 u16 red = cmap->red[i];
1141                 u16 green = cmap->green[i];
1142                 u16 blue = cmap->blue[i];
1143                 u32 value;
1144
1145                 red >>= 16 - info->var.red.length;
1146                 green >>= 16 - info->var.green.length;
1147                 blue >>= 16 - info->var.blue.length;
1148                 value = (red << info->var.red.offset) |
1149                         (green << info->var.green.offset) |
1150                         (blue << info->var.blue.offset);
1151                 if (info->var.transp.length > 0) {
1152                         u32 mask = (1 << info->var.transp.length) - 1;
1153
1154                         mask <<= info->var.transp.offset;
1155                         value |= mask;
1156                 }
1157                 palette[cmap->start + i] = value;
1158         }
1159
1160         return 0;
1161 }
1162
1163 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
1164 {
1165         struct drm_fb_helper *fb_helper = info->par;
1166         struct drm_mode_set *modeset;
1167         struct drm_crtc *crtc;
1168         u16 *r, *g, *b;
1169         int ret = 0;
1170
1171         drm_modeset_lock_all(fb_helper->dev);
1172         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1173                 crtc = modeset->crtc;
1174                 if (!crtc->funcs->gamma_set || !crtc->gamma_size) {
1175                         ret = -EINVAL;
1176                         goto out;
1177                 }
1178
1179                 if (cmap->start + cmap->len > crtc->gamma_size) {
1180                         ret = -EINVAL;
1181                         goto out;
1182                 }
1183
1184                 r = crtc->gamma_store;
1185                 g = r + crtc->gamma_size;
1186                 b = g + crtc->gamma_size;
1187
1188                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1189                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1190                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1191
1192                 ret = crtc->funcs->gamma_set(crtc, r, g, b,
1193                                              crtc->gamma_size, NULL);
1194                 if (ret)
1195                         goto out;
1196         }
1197 out:
1198         drm_modeset_unlock_all(fb_helper->dev);
1199
1200         return ret;
1201 }
1202
1203 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
1204                                                        struct fb_cmap *cmap)
1205 {
1206         struct drm_device *dev = crtc->dev;
1207         struct drm_property_blob *gamma_lut;
1208         struct drm_color_lut *lut;
1209         int size = crtc->gamma_size;
1210         int i;
1211
1212         if (!size || cmap->start + cmap->len > size)
1213                 return ERR_PTR(-EINVAL);
1214
1215         gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
1216         if (IS_ERR(gamma_lut))
1217                 return gamma_lut;
1218
1219         lut = gamma_lut->data;
1220         if (cmap->start || cmap->len != size) {
1221                 u16 *r = crtc->gamma_store;
1222                 u16 *g = r + crtc->gamma_size;
1223                 u16 *b = g + crtc->gamma_size;
1224
1225                 for (i = 0; i < cmap->start; i++) {
1226                         lut[i].red = r[i];
1227                         lut[i].green = g[i];
1228                         lut[i].blue = b[i];
1229                 }
1230                 for (i = cmap->start + cmap->len; i < size; i++) {
1231                         lut[i].red = r[i];
1232                         lut[i].green = g[i];
1233                         lut[i].blue = b[i];
1234                 }
1235         }
1236
1237         for (i = 0; i < cmap->len; i++) {
1238                 lut[cmap->start + i].red = cmap->red[i];
1239                 lut[cmap->start + i].green = cmap->green[i];
1240                 lut[cmap->start + i].blue = cmap->blue[i];
1241         }
1242
1243         return gamma_lut;
1244 }
1245
1246 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
1247 {
1248         struct drm_fb_helper *fb_helper = info->par;
1249         struct drm_device *dev = fb_helper->dev;
1250         struct drm_property_blob *gamma_lut = NULL;
1251         struct drm_modeset_acquire_ctx ctx;
1252         struct drm_crtc_state *crtc_state;
1253         struct drm_atomic_state *state;
1254         struct drm_mode_set *modeset;
1255         struct drm_crtc *crtc;
1256         u16 *r, *g, *b;
1257         bool replaced;
1258         int ret = 0;
1259
1260         drm_modeset_acquire_init(&ctx, 0);
1261
1262         state = drm_atomic_state_alloc(dev);
1263         if (!state) {
1264                 ret = -ENOMEM;
1265                 goto out_ctx;
1266         }
1267
1268         state->acquire_ctx = &ctx;
1269 retry:
1270         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1271                 crtc = modeset->crtc;
1272
1273                 if (!gamma_lut)
1274                         gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1275                 if (IS_ERR(gamma_lut)) {
1276                         ret = PTR_ERR(gamma_lut);
1277                         gamma_lut = NULL;
1278                         goto out_state;
1279                 }
1280
1281                 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1282                 if (IS_ERR(crtc_state)) {
1283                         ret = PTR_ERR(crtc_state);
1284                         goto out_state;
1285                 }
1286
1287                 /*
1288                  * FIXME: This always uses gamma_lut. Some HW have only
1289                  * degamma_lut, in which case we should reset gamma_lut and set
1290                  * degamma_lut. See drm_crtc_legacy_gamma_set().
1291                  */
1292                 replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1293                                                       NULL);
1294                 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1295                 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1296                                                       gamma_lut);
1297                 crtc_state->color_mgmt_changed |= replaced;
1298         }
1299
1300         ret = drm_atomic_commit(state);
1301         if (ret)
1302                 goto out_state;
1303
1304         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1305                 crtc = modeset->crtc;
1306
1307                 r = crtc->gamma_store;
1308                 g = r + crtc->gamma_size;
1309                 b = g + crtc->gamma_size;
1310
1311                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1312                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1313                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1314         }
1315
1316 out_state:
1317         if (ret == -EDEADLK)
1318                 goto backoff;
1319
1320         drm_property_blob_put(gamma_lut);
1321         drm_atomic_state_put(state);
1322 out_ctx:
1323         drm_modeset_drop_locks(&ctx);
1324         drm_modeset_acquire_fini(&ctx);
1325
1326         return ret;
1327
1328 backoff:
1329         drm_atomic_state_clear(state);
1330         drm_modeset_backoff(&ctx);
1331         goto retry;
1332 }
1333
1334 /**
1335  * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1336  * @cmap: cmap to set
1337  * @info: fbdev registered by the helper
1338  */
1339 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1340 {
1341         struct drm_fb_helper *fb_helper = info->par;
1342         struct drm_device *dev = fb_helper->dev;
1343         int ret;
1344
1345         if (oops_in_progress)
1346                 return -EBUSY;
1347
1348         mutex_lock(&fb_helper->lock);
1349
1350         if (!drm_master_internal_acquire(dev)) {
1351                 ret = -EBUSY;
1352                 goto unlock;
1353         }
1354
1355         mutex_lock(&fb_helper->client.modeset_mutex);
1356         if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1357                 ret = setcmap_pseudo_palette(cmap, info);
1358         else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1359                 ret = setcmap_atomic(cmap, info);
1360         else
1361                 ret = setcmap_legacy(cmap, info);
1362         mutex_unlock(&fb_helper->client.modeset_mutex);
1363
1364         drm_master_internal_release(dev);
1365 unlock:
1366         mutex_unlock(&fb_helper->lock);
1367
1368         return ret;
1369 }
1370 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1371
1372 /**
1373  * drm_fb_helper_ioctl - legacy ioctl implementation
1374  * @info: fbdev registered by the helper
1375  * @cmd: ioctl command
1376  * @arg: ioctl argument
1377  *
1378  * A helper to implement the standard fbdev ioctl. Only
1379  * FBIO_WAITFORVSYNC is implemented for now.
1380  */
1381 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1382                         unsigned long arg)
1383 {
1384         struct drm_fb_helper *fb_helper = info->par;
1385         struct drm_device *dev = fb_helper->dev;
1386         struct drm_crtc *crtc;
1387         int ret = 0;
1388
1389         mutex_lock(&fb_helper->lock);
1390         if (!drm_master_internal_acquire(dev)) {
1391                 ret = -EBUSY;
1392                 goto unlock;
1393         }
1394
1395         switch (cmd) {
1396         case FBIO_WAITFORVSYNC:
1397                 /*
1398                  * Only consider the first CRTC.
1399                  *
1400                  * This ioctl is supposed to take the CRTC number as
1401                  * an argument, but in fbdev times, what that number
1402                  * was supposed to be was quite unclear, different
1403                  * drivers were passing that argument differently
1404                  * (some by reference, some by value), and most of the
1405                  * userspace applications were just hardcoding 0 as an
1406                  * argument.
1407                  *
1408                  * The first CRTC should be the integrated panel on
1409                  * most drivers, so this is the best choice we can
1410                  * make. If we're not smart enough here, one should
1411                  * just consider switch the userspace to KMS.
1412                  */
1413                 crtc = fb_helper->client.modesets[0].crtc;
1414
1415                 /*
1416                  * Only wait for a vblank event if the CRTC is
1417                  * enabled, otherwise just don't do anythintg,
1418                  * not even report an error.
1419                  */
1420                 ret = drm_crtc_vblank_get(crtc);
1421                 if (!ret) {
1422                         drm_crtc_wait_one_vblank(crtc);
1423                         drm_crtc_vblank_put(crtc);
1424                 }
1425
1426                 ret = 0;
1427                 break;
1428         default:
1429                 ret = -ENOTTY;
1430         }
1431
1432         drm_master_internal_release(dev);
1433 unlock:
1434         mutex_unlock(&fb_helper->lock);
1435         return ret;
1436 }
1437 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1438
1439 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1440                                       const struct fb_var_screeninfo *var_2)
1441 {
1442         return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1443                var_1->grayscale == var_2->grayscale &&
1444                var_1->red.offset == var_2->red.offset &&
1445                var_1->red.length == var_2->red.length &&
1446                var_1->red.msb_right == var_2->red.msb_right &&
1447                var_1->green.offset == var_2->green.offset &&
1448                var_1->green.length == var_2->green.length &&
1449                var_1->green.msb_right == var_2->green.msb_right &&
1450                var_1->blue.offset == var_2->blue.offset &&
1451                var_1->blue.length == var_2->blue.length &&
1452                var_1->blue.msb_right == var_2->blue.msb_right &&
1453                var_1->transp.offset == var_2->transp.offset &&
1454                var_1->transp.length == var_2->transp.length &&
1455                var_1->transp.msb_right == var_2->transp.msb_right;
1456 }
1457
1458 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1459                                          const struct drm_format_info *format)
1460 {
1461         u8 depth = format->depth;
1462
1463         if (format->is_color_indexed) {
1464                 var->red.offset = 0;
1465                 var->green.offset = 0;
1466                 var->blue.offset = 0;
1467                 var->red.length = depth;
1468                 var->green.length = depth;
1469                 var->blue.length = depth;
1470                 var->transp.offset = 0;
1471                 var->transp.length = 0;
1472                 return;
1473         }
1474
1475         switch (depth) {
1476         case 15:
1477                 var->red.offset = 10;
1478                 var->green.offset = 5;
1479                 var->blue.offset = 0;
1480                 var->red.length = 5;
1481                 var->green.length = 5;
1482                 var->blue.length = 5;
1483                 var->transp.offset = 15;
1484                 var->transp.length = 1;
1485                 break;
1486         case 16:
1487                 var->red.offset = 11;
1488                 var->green.offset = 5;
1489                 var->blue.offset = 0;
1490                 var->red.length = 5;
1491                 var->green.length = 6;
1492                 var->blue.length = 5;
1493                 var->transp.offset = 0;
1494                 break;
1495         case 24:
1496                 var->red.offset = 16;
1497                 var->green.offset = 8;
1498                 var->blue.offset = 0;
1499                 var->red.length = 8;
1500                 var->green.length = 8;
1501                 var->blue.length = 8;
1502                 var->transp.offset = 0;
1503                 var->transp.length = 0;
1504                 break;
1505         case 32:
1506                 var->red.offset = 16;
1507                 var->green.offset = 8;
1508                 var->blue.offset = 0;
1509                 var->red.length = 8;
1510                 var->green.length = 8;
1511                 var->blue.length = 8;
1512                 var->transp.offset = 24;
1513                 var->transp.length = 8;
1514                 break;
1515         default:
1516                 break;
1517         }
1518 }
1519
1520 /**
1521  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1522  * @var: screeninfo to check
1523  * @info: fbdev registered by the helper
1524  */
1525 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1526                             struct fb_info *info)
1527 {
1528         struct drm_fb_helper *fb_helper = info->par;
1529         struct drm_framebuffer *fb = fb_helper->fb;
1530         const struct drm_format_info *format = fb->format;
1531         struct drm_device *dev = fb_helper->dev;
1532         unsigned int bpp;
1533
1534         if (in_dbg_master())
1535                 return -EINVAL;
1536
1537         if (var->pixclock != 0) {
1538                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1539                 var->pixclock = 0;
1540         }
1541
1542         switch (format->format) {
1543         case DRM_FORMAT_C1:
1544         case DRM_FORMAT_C2:
1545         case DRM_FORMAT_C4:
1546                 /* supported format with sub-byte pixels */
1547                 break;
1548
1549         default:
1550                 if ((drm_format_info_block_width(format, 0) > 1) ||
1551                     (drm_format_info_block_height(format, 0) > 1))
1552                         return -EINVAL;
1553                 break;
1554         }
1555
1556         /*
1557          * Changes struct fb_var_screeninfo are currently not pushed back
1558          * to KMS, hence fail if different settings are requested.
1559          */
1560         bpp = drm_format_info_bpp(format, 0);
1561         if (var->bits_per_pixel > bpp ||
1562             var->xres > fb->width || var->yres > fb->height ||
1563             var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1564                 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1565                           "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1566                           var->xres, var->yres, var->bits_per_pixel,
1567                           var->xres_virtual, var->yres_virtual,
1568                           fb->width, fb->height, bpp);
1569                 return -EINVAL;
1570         }
1571
1572         /*
1573          * Workaround for SDL 1.2, which is known to be setting all pixel format
1574          * fields values to zero in some cases. We treat this situation as a
1575          * kind of "use some reasonable autodetected values".
1576          */
1577         if (!var->red.offset     && !var->green.offset    &&
1578             !var->blue.offset    && !var->transp.offset   &&
1579             !var->red.length     && !var->green.length    &&
1580             !var->blue.length    && !var->transp.length   &&
1581             !var->red.msb_right  && !var->green.msb_right &&
1582             !var->blue.msb_right && !var->transp.msb_right) {
1583                 drm_fb_helper_fill_pixel_fmt(var, format);
1584         }
1585
1586         /*
1587          * Likewise, bits_per_pixel should be rounded up to a supported value.
1588          */
1589         var->bits_per_pixel = bpp;
1590
1591         /*
1592          * drm fbdev emulation doesn't support changing the pixel format at all,
1593          * so reject all pixel format changing requests.
1594          */
1595         if (!drm_fb_pixel_format_equal(var, &info->var)) {
1596                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1597                 return -EINVAL;
1598         }
1599
1600         return 0;
1601 }
1602 EXPORT_SYMBOL(drm_fb_helper_check_var);
1603
1604 /**
1605  * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1606  * @info: fbdev registered by the helper
1607  *
1608  * This will let fbcon do the mode init and is called at initialization time by
1609  * the fbdev core when registering the driver, and later on through the hotplug
1610  * callback.
1611  */
1612 int drm_fb_helper_set_par(struct fb_info *info)
1613 {
1614         struct drm_fb_helper *fb_helper = info->par;
1615         struct fb_var_screeninfo *var = &info->var;
1616         bool force;
1617
1618         if (oops_in_progress)
1619                 return -EBUSY;
1620
1621         if (var->pixclock != 0) {
1622                 drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1623                 return -EINVAL;
1624         }
1625
1626         /*
1627          * Normally we want to make sure that a kms master takes precedence over
1628          * fbdev, to avoid fbdev flickering and occasionally stealing the
1629          * display status. But Xorg first sets the vt back to text mode using
1630          * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1631          * status when exiting.
1632          *
1633          * In the past this was caught by drm_fb_helper_lastclose(), but on
1634          * modern systems where logind always keeps a drm fd open to orchestrate
1635          * the vt switching, this doesn't work.
1636          *
1637          * To not break the userspace ABI we have this special case here, which
1638          * is only used for the above case. Everything else uses the normal
1639          * commit function, which ensures that we never steal the display from
1640          * an active drm master.
1641          */
1642         force = var->activate & FB_ACTIVATE_KD_TEXT;
1643
1644         __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1645
1646         return 0;
1647 }
1648 EXPORT_SYMBOL(drm_fb_helper_set_par);
1649
1650 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1651 {
1652         struct drm_mode_set *mode_set;
1653
1654         mutex_lock(&fb_helper->client.modeset_mutex);
1655         drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1656                 mode_set->x = x;
1657                 mode_set->y = y;
1658         }
1659         mutex_unlock(&fb_helper->client.modeset_mutex);
1660 }
1661
1662 static int pan_display_atomic(struct fb_var_screeninfo *var,
1663                               struct fb_info *info)
1664 {
1665         struct drm_fb_helper *fb_helper = info->par;
1666         int ret;
1667
1668         pan_set(fb_helper, var->xoffset, var->yoffset);
1669
1670         ret = drm_client_modeset_commit_locked(&fb_helper->client);
1671         if (!ret) {
1672                 info->var.xoffset = var->xoffset;
1673                 info->var.yoffset = var->yoffset;
1674         } else
1675                 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1676
1677         return ret;
1678 }
1679
1680 static int pan_display_legacy(struct fb_var_screeninfo *var,
1681                               struct fb_info *info)
1682 {
1683         struct drm_fb_helper *fb_helper = info->par;
1684         struct drm_client_dev *client = &fb_helper->client;
1685         struct drm_mode_set *modeset;
1686         int ret = 0;
1687
1688         mutex_lock(&client->modeset_mutex);
1689         drm_modeset_lock_all(fb_helper->dev);
1690         drm_client_for_each_modeset(modeset, client) {
1691                 modeset->x = var->xoffset;
1692                 modeset->y = var->yoffset;
1693
1694                 if (modeset->num_connectors) {
1695                         ret = drm_mode_set_config_internal(modeset);
1696                         if (!ret) {
1697                                 info->var.xoffset = var->xoffset;
1698                                 info->var.yoffset = var->yoffset;
1699                         }
1700                 }
1701         }
1702         drm_modeset_unlock_all(fb_helper->dev);
1703         mutex_unlock(&client->modeset_mutex);
1704
1705         return ret;
1706 }
1707
1708 /**
1709  * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1710  * @var: updated screen information
1711  * @info: fbdev registered by the helper
1712  */
1713 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1714                               struct fb_info *info)
1715 {
1716         struct drm_fb_helper *fb_helper = info->par;
1717         struct drm_device *dev = fb_helper->dev;
1718         int ret;
1719
1720         if (oops_in_progress)
1721                 return -EBUSY;
1722
1723         mutex_lock(&fb_helper->lock);
1724         if (!drm_master_internal_acquire(dev)) {
1725                 ret = -EBUSY;
1726                 goto unlock;
1727         }
1728
1729         if (drm_drv_uses_atomic_modeset(dev))
1730                 ret = pan_display_atomic(var, info);
1731         else
1732                 ret = pan_display_legacy(var, info);
1733
1734         drm_master_internal_release(dev);
1735 unlock:
1736         mutex_unlock(&fb_helper->lock);
1737
1738         return ret;
1739 }
1740 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1741
1742 static uint32_t drm_fb_helper_find_format(struct drm_fb_helper *fb_helper, const uint32_t *formats,
1743                                           size_t format_count, uint32_t bpp, uint32_t depth)
1744 {
1745         struct drm_device *dev = fb_helper->dev;
1746         uint32_t format;
1747         size_t i;
1748
1749         /*
1750          * Do not consider YUV or other complicated formats
1751          * for framebuffers. This means only legacy formats
1752          * are supported (fmt->depth is a legacy field), but
1753          * the framebuffer emulation can only deal with such
1754          * formats, specifically RGB/BGA formats.
1755          */
1756         format = drm_mode_legacy_fb_format(bpp, depth);
1757         if (!format)
1758                 goto err;
1759
1760         for (i = 0; i < format_count; ++i) {
1761                 if (formats[i] == format)
1762                         return format;
1763         }
1764
1765 err:
1766         /* We found nothing. */
1767         drm_warn(dev, "bpp/depth value of %u/%u not supported\n", bpp, depth);
1768
1769         return DRM_FORMAT_INVALID;
1770 }
1771
1772 static uint32_t drm_fb_helper_find_color_mode_format(struct drm_fb_helper *fb_helper,
1773                                                      const uint32_t *formats, size_t format_count,
1774                                                      unsigned int color_mode)
1775 {
1776         struct drm_device *dev = fb_helper->dev;
1777         uint32_t bpp, depth;
1778
1779         switch (color_mode) {
1780         case 1:
1781         case 2:
1782         case 4:
1783         case 8:
1784         case 16:
1785         case 24:
1786                 bpp = depth = color_mode;
1787                 break;
1788         case 15:
1789                 bpp = 16;
1790                 depth = 15;
1791                 break;
1792         case 32:
1793                 bpp = 32;
1794                 depth = 24;
1795                 break;
1796         default:
1797                 drm_info(dev, "unsupported color mode of %d\n", color_mode);
1798                 return DRM_FORMAT_INVALID;
1799         }
1800
1801         return drm_fb_helper_find_format(fb_helper, formats, format_count, bpp, depth);
1802 }
1803
1804 static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper,
1805                                       struct drm_fb_helper_surface_size *sizes)
1806 {
1807         struct drm_client_dev *client = &fb_helper->client;
1808         struct drm_device *dev = fb_helper->dev;
1809         int crtc_count = 0;
1810         struct drm_connector_list_iter conn_iter;
1811         struct drm_connector *connector;
1812         struct drm_mode_set *mode_set;
1813         uint32_t surface_format = DRM_FORMAT_INVALID;
1814         const struct drm_format_info *info;
1815
1816         memset(sizes, 0, sizeof(*sizes));
1817         sizes->fb_width = (u32)-1;
1818         sizes->fb_height = (u32)-1;
1819
1820         drm_client_for_each_modeset(mode_set, client) {
1821                 struct drm_crtc *crtc = mode_set->crtc;
1822                 struct drm_plane *plane = crtc->primary;
1823
1824                 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1825
1826                 drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1827                 drm_client_for_each_connector_iter(connector, &conn_iter) {
1828                         struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
1829
1830                         if (!cmdline_mode->bpp_specified)
1831                                 continue;
1832
1833                         surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1834                                                                               plane->format_types,
1835                                                                               plane->format_count,
1836                                                                               cmdline_mode->bpp);
1837                         if (surface_format != DRM_FORMAT_INVALID)
1838                                 break; /* found supported format */
1839                 }
1840                 drm_connector_list_iter_end(&conn_iter);
1841
1842                 if (surface_format != DRM_FORMAT_INVALID)
1843                         break; /* found supported format */
1844
1845                 /* try preferred color mode */
1846                 surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
1847                                                                       plane->format_types,
1848                                                                       plane->format_count,
1849                                                                       fb_helper->preferred_bpp);
1850                 if (surface_format != DRM_FORMAT_INVALID)
1851                         break; /* found supported format */
1852         }
1853
1854         if (surface_format == DRM_FORMAT_INVALID) {
1855                 /*
1856                  * If none of the given color modes works, fall back
1857                  * to XRGB8888. Drivers are expected to provide this
1858                  * format for compatibility with legacy applications.
1859                  */
1860                 drm_warn(dev, "No compatible format found\n");
1861                 surface_format = drm_driver_legacy_fb_format(dev, 32, 24);
1862         }
1863
1864         info = drm_format_info(surface_format);
1865         sizes->surface_bpp = drm_format_info_bpp(info, 0);
1866         sizes->surface_depth = info->depth;
1867
1868         /* first up get a count of crtcs now in use and new min/maxes width/heights */
1869         crtc_count = 0;
1870         drm_client_for_each_modeset(mode_set, client) {
1871                 struct drm_display_mode *desired_mode;
1872                 int x, y, j;
1873                 /* in case of tile group, are we the last tile vert or horiz?
1874                  * If no tile group you are always the last one both vertically
1875                  * and horizontally
1876                  */
1877                 bool lastv = true, lasth = true;
1878
1879                 desired_mode = mode_set->mode;
1880
1881                 if (!desired_mode)
1882                         continue;
1883
1884                 crtc_count++;
1885
1886                 x = mode_set->x;
1887                 y = mode_set->y;
1888
1889                 sizes->surface_width  =
1890                         max_t(u32, desired_mode->hdisplay + x, sizes->surface_width);
1891                 sizes->surface_height =
1892                         max_t(u32, desired_mode->vdisplay + y, sizes->surface_height);
1893
1894                 for (j = 0; j < mode_set->num_connectors; j++) {
1895                         struct drm_connector *connector = mode_set->connectors[j];
1896
1897                         if (connector->has_tile &&
1898                             desired_mode->hdisplay == connector->tile_h_size &&
1899                             desired_mode->vdisplay == connector->tile_v_size) {
1900                                 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1901                                 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1902                                 /* cloning to multiple tiles is just crazy-talk, so: */
1903                                 break;
1904                         }
1905                 }
1906
1907                 if (lasth)
1908                         sizes->fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes->fb_width);
1909                 if (lastv)
1910                         sizes->fb_height = min_t(u32, desired_mode->vdisplay + y, sizes->fb_height);
1911         }
1912
1913         if (crtc_count == 0 || sizes->fb_width == -1 || sizes->fb_height == -1) {
1914                 drm_info(dev, "Cannot find any crtc or sizes\n");
1915                 return -EAGAIN;
1916         }
1917
1918         return 0;
1919 }
1920
1921 static int drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper,
1922                                     struct drm_fb_helper_surface_size *sizes)
1923 {
1924         struct drm_client_dev *client = &fb_helper->client;
1925         struct drm_device *dev = fb_helper->dev;
1926         struct drm_mode_config *config = &dev->mode_config;
1927         int ret;
1928
1929         mutex_lock(&client->modeset_mutex);
1930         ret = __drm_fb_helper_find_sizes(fb_helper, sizes);
1931         mutex_unlock(&client->modeset_mutex);
1932
1933         if (ret)
1934                 return ret;
1935
1936         /* Handle our overallocation */
1937         sizes->surface_height *= drm_fbdev_overalloc;
1938         sizes->surface_height /= 100;
1939         if (sizes->surface_height > config->max_height) {
1940                 drm_dbg_kms(dev, "Fbdev over-allocation too large; clamping height to %d\n",
1941                             config->max_height);
1942                 sizes->surface_height = config->max_height;
1943         }
1944
1945         return 0;
1946 }
1947
1948 /*
1949  * Allocates the backing storage and sets up the fbdev info structure through
1950  * the ->fb_probe callback.
1951  */
1952 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper)
1953 {
1954         struct drm_client_dev *client = &fb_helper->client;
1955         struct drm_device *dev = fb_helper->dev;
1956         struct drm_fb_helper_surface_size sizes;
1957         int ret;
1958
1959         ret = drm_fb_helper_find_sizes(fb_helper, &sizes);
1960         if (ret) {
1961                 /* First time: disable all crtc's.. */
1962                 if (!fb_helper->deferred_setup)
1963                         drm_client_modeset_commit(client);
1964                 return ret;
1965         }
1966
1967 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1968         fb_helper->hint_leak_smem_start = drm_leak_fbdev_smem;
1969 #endif
1970
1971         /* push down into drivers */
1972         ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1973         if (ret < 0)
1974                 return ret;
1975
1976         strcpy(fb_helper->fb->comm, "[fbcon]");
1977
1978         /* Set the fb info for vgaswitcheroo clients. Does nothing otherwise. */
1979         if (dev_is_pci(dev->dev))
1980                 vga_switcheroo_client_fb_set(to_pci_dev(dev->dev), fb_helper->info);
1981
1982         return 0;
1983 }
1984
1985 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1986                                    bool is_color_indexed)
1987 {
1988         info->fix.type = FB_TYPE_PACKED_PIXELS;
1989         info->fix.visual = is_color_indexed ? FB_VISUAL_PSEUDOCOLOR
1990                                             : FB_VISUAL_TRUECOLOR;
1991         info->fix.mmio_start = 0;
1992         info->fix.mmio_len = 0;
1993         info->fix.type_aux = 0;
1994         info->fix.xpanstep = 1; /* doing it in hw */
1995         info->fix.ypanstep = 1; /* doing it in hw */
1996         info->fix.ywrapstep = 0;
1997         info->fix.accel = FB_ACCEL_NONE;
1998
1999         info->fix.line_length = pitch;
2000 }
2001
2002 static void drm_fb_helper_fill_var(struct fb_info *info,
2003                                    struct drm_fb_helper *fb_helper,
2004                                    uint32_t fb_width, uint32_t fb_height)
2005 {
2006         struct drm_framebuffer *fb = fb_helper->fb;
2007         const struct drm_format_info *format = fb->format;
2008
2009         switch (format->format) {
2010         case DRM_FORMAT_C1:
2011         case DRM_FORMAT_C2:
2012         case DRM_FORMAT_C4:
2013                 /* supported format with sub-byte pixels */
2014                 break;
2015
2016         default:
2017                 WARN_ON((drm_format_info_block_width(format, 0) > 1) ||
2018                         (drm_format_info_block_height(format, 0) > 1));
2019                 break;
2020         }
2021
2022         info->pseudo_palette = fb_helper->pseudo_palette;
2023         info->var.xres_virtual = fb->width;
2024         info->var.yres_virtual = fb->height;
2025         info->var.bits_per_pixel = drm_format_info_bpp(format, 0);
2026         info->var.accel_flags = FB_ACCELF_TEXT;
2027         info->var.xoffset = 0;
2028         info->var.yoffset = 0;
2029         info->var.activate = FB_ACTIVATE_NOW;
2030
2031         drm_fb_helper_fill_pixel_fmt(&info->var, format);
2032
2033         info->var.xres = fb_width;
2034         info->var.yres = fb_height;
2035 }
2036
2037 /**
2038  * drm_fb_helper_fill_info - initializes fbdev information
2039  * @info: fbdev instance to set up
2040  * @fb_helper: fb helper instance to use as template
2041  * @sizes: describes fbdev size and scanout surface size
2042  *
2043  * Sets up the variable and fixed fbdev metainformation from the given fb helper
2044  * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
2045  *
2046  * Drivers should call this (or their equivalent setup code) from their
2047  * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
2048  * backing storage framebuffer.
2049  */
2050 void drm_fb_helper_fill_info(struct fb_info *info,
2051                              struct drm_fb_helper *fb_helper,
2052                              struct drm_fb_helper_surface_size *sizes)
2053 {
2054         struct drm_framebuffer *fb = fb_helper->fb;
2055
2056         drm_fb_helper_fill_fix(info, fb->pitches[0],
2057                                fb->format->is_color_indexed);
2058         drm_fb_helper_fill_var(info, fb_helper,
2059                                sizes->fb_width, sizes->fb_height);
2060
2061         info->par = fb_helper;
2062         /*
2063          * The DRM drivers fbdev emulation device name can be confusing if the
2064          * driver name also has a "drm" suffix on it. Leading to names such as
2065          * "simpledrmdrmfb" in /proc/fb. Unfortunately, it's an uAPI and can't
2066          * be changed due user-space tools (e.g: pm-utils) matching against it.
2067          */
2068         snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
2069                  fb_helper->dev->driver->name);
2070
2071 }
2072 EXPORT_SYMBOL(drm_fb_helper_fill_info);
2073
2074 /*
2075  * This is a continuation of drm_setup_crtcs() that sets up anything related
2076  * to the framebuffer. During initialization, drm_setup_crtcs() is called before
2077  * the framebuffer has been allocated (fb_helper->fb and fb_helper->info).
2078  * So, any setup that touches those fields needs to be done here instead of in
2079  * drm_setup_crtcs().
2080  */
2081 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
2082 {
2083         struct drm_client_dev *client = &fb_helper->client;
2084         struct drm_connector_list_iter conn_iter;
2085         struct fb_info *info = fb_helper->info;
2086         unsigned int rotation, sw_rotations = 0;
2087         struct drm_connector *connector;
2088         struct drm_mode_set *modeset;
2089
2090         mutex_lock(&client->modeset_mutex);
2091         drm_client_for_each_modeset(modeset, client) {
2092                 if (!modeset->num_connectors)
2093                         continue;
2094
2095                 modeset->fb = fb_helper->fb;
2096
2097                 if (drm_client_rotation(modeset, &rotation))
2098                         /* Rotating in hardware, fbcon should not rotate */
2099                         sw_rotations |= DRM_MODE_ROTATE_0;
2100                 else
2101                         sw_rotations |= rotation;
2102         }
2103         mutex_unlock(&client->modeset_mutex);
2104
2105         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
2106         drm_client_for_each_connector_iter(connector, &conn_iter) {
2107
2108                 /* use first connected connector for the physical dimensions */
2109                 if (connector->status == connector_status_connected) {
2110                         info->var.width = connector->display_info.width_mm;
2111                         info->var.height = connector->display_info.height_mm;
2112                         break;
2113                 }
2114         }
2115         drm_connector_list_iter_end(&conn_iter);
2116
2117         switch (sw_rotations) {
2118         case DRM_MODE_ROTATE_0:
2119                 info->fbcon_rotate_hint = FB_ROTATE_UR;
2120                 break;
2121         case DRM_MODE_ROTATE_90:
2122                 info->fbcon_rotate_hint = FB_ROTATE_CCW;
2123                 break;
2124         case DRM_MODE_ROTATE_180:
2125                 info->fbcon_rotate_hint = FB_ROTATE_UD;
2126                 break;
2127         case DRM_MODE_ROTATE_270:
2128                 info->fbcon_rotate_hint = FB_ROTATE_CW;
2129                 break;
2130         default:
2131                 /*
2132                  * Multiple bits are set / multiple rotations requested
2133                  * fbcon cannot handle separate rotation settings per
2134                  * output, so fallback to unrotated.
2135                  */
2136                 info->fbcon_rotate_hint = FB_ROTATE_UR;
2137         }
2138 }
2139
2140 /* Note: Drops fb_helper->lock before returning. */
2141 static int
2142 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper)
2143 {
2144         struct drm_device *dev = fb_helper->dev;
2145         struct fb_info *info;
2146         unsigned int width, height;
2147         int ret;
2148
2149         width = dev->mode_config.max_width;
2150         height = dev->mode_config.max_height;
2151
2152         drm_client_modeset_probe(&fb_helper->client, width, height);
2153         ret = drm_fb_helper_single_fb_probe(fb_helper);
2154         if (ret < 0) {
2155                 if (ret == -EAGAIN) {
2156                         fb_helper->deferred_setup = true;
2157                         ret = 0;
2158                 }
2159                 mutex_unlock(&fb_helper->lock);
2160
2161                 return ret;
2162         }
2163         drm_setup_crtcs_fb(fb_helper);
2164
2165         fb_helper->deferred_setup = false;
2166
2167         info = fb_helper->info;
2168         info->var.pixclock = 0;
2169         /* Shamelessly allow physical address leaking to userspace */
2170 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2171         if (!fb_helper->hint_leak_smem_start)
2172 #endif
2173                 /* don't leak any physical addresses to userspace */
2174                 info->flags |= FBINFO_HIDE_SMEM_START;
2175
2176         /* Need to drop locks to avoid recursive deadlock in
2177          * register_framebuffer. This is ok because the only thing left to do is
2178          * register the fbdev emulation instance in kernel_fb_helper_list. */
2179         mutex_unlock(&fb_helper->lock);
2180
2181         ret = register_framebuffer(info);
2182         if (ret < 0)
2183                 return ret;
2184
2185         drm_info(dev, "fb%d: %s frame buffer device\n",
2186                  info->node, info->fix.id);
2187
2188         mutex_lock(&kernel_fb_helper_lock);
2189         if (list_empty(&kernel_fb_helper_list))
2190                 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
2191
2192         list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
2193         mutex_unlock(&kernel_fb_helper_lock);
2194
2195         return 0;
2196 }
2197
2198 /**
2199  * drm_fb_helper_initial_config - setup a sane initial connector configuration
2200  * @fb_helper: fb_helper device struct
2201  *
2202  * Scans the CRTCs and connectors and tries to put together an initial setup.
2203  * At the moment, this is a cloned configuration across all heads with
2204  * a new framebuffer object as the backing store.
2205  *
2206  * Note that this also registers the fbdev and so allows userspace to call into
2207  * the driver through the fbdev interfaces.
2208  *
2209  * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
2210  * to let the driver allocate and initialize the fbdev info structure and the
2211  * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
2212  * as a helper to setup simple default values for the fbdev info structure.
2213  *
2214  * HANG DEBUGGING:
2215  *
2216  * When you have fbcon support built-in or already loaded, this function will do
2217  * a full modeset to setup the fbdev console. Due to locking misdesign in the
2218  * VT/fbdev subsystem that entire modeset sequence has to be done while holding
2219  * console_lock. Until console_unlock is called no dmesg lines will be sent out
2220  * to consoles, not even serial console. This means when your driver crashes,
2221  * you will see absolutely nothing else but a system stuck in this function,
2222  * with no further output. Any kind of printk() you place within your own driver
2223  * or in the drm core modeset code will also never show up.
2224  *
2225  * Standard debug practice is to run the fbcon setup without taking the
2226  * console_lock as a hack, to be able to see backtraces and crashes on the
2227  * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
2228  * cmdline option.
2229  *
2230  * The other option is to just disable fbdev emulation since very likely the
2231  * first modeset from userspace will crash in the same way, and is even easier
2232  * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
2233  * kernel cmdline option.
2234  *
2235  * RETURNS:
2236  * Zero if everything went ok, nonzero otherwise.
2237  */
2238 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper)
2239 {
2240         int ret;
2241
2242         if (!drm_fbdev_emulation)
2243                 return 0;
2244
2245         mutex_lock(&fb_helper->lock);
2246         ret = __drm_fb_helper_initial_config_and_unlock(fb_helper);
2247
2248         return ret;
2249 }
2250 EXPORT_SYMBOL(drm_fb_helper_initial_config);
2251
2252 /**
2253  * drm_fb_helper_hotplug_event - respond to a hotplug notification by
2254  *                               probing all the outputs attached to the fb
2255  * @fb_helper: driver-allocated fbdev helper, can be NULL
2256  *
2257  * Scan the connectors attached to the fb_helper and try to put together a
2258  * setup after notification of a change in output configuration.
2259  *
2260  * Called at runtime, takes the mode config locks to be able to check/change the
2261  * modeset configuration. Must be run from process context (which usually means
2262  * either the output polling work or a work item launched from the driver's
2263  * hotplug interrupt).
2264  *
2265  * Note that drivers may call this even before calling
2266  * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
2267  * for a race-free fbcon setup and will make sure that the fbdev emulation will
2268  * not miss any hotplug events.
2269  *
2270  * RETURNS:
2271  * 0 on success and a non-zero error code otherwise.
2272  */
2273 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
2274 {
2275         int err = 0;
2276
2277         if (!drm_fbdev_emulation || !fb_helper)
2278                 return 0;
2279
2280         mutex_lock(&fb_helper->lock);
2281         if (fb_helper->deferred_setup) {
2282                 err = __drm_fb_helper_initial_config_and_unlock(fb_helper);
2283                 return err;
2284         }
2285
2286         if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
2287                 fb_helper->delayed_hotplug = true;
2288                 mutex_unlock(&fb_helper->lock);
2289                 return err;
2290         }
2291
2292         drm_master_internal_release(fb_helper->dev);
2293
2294         drm_dbg_kms(fb_helper->dev, "\n");
2295
2296         drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
2297         drm_setup_crtcs_fb(fb_helper);
2298         mutex_unlock(&fb_helper->lock);
2299
2300         drm_fb_helper_set_par(fb_helper->info);
2301
2302         return 0;
2303 }
2304 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
2305
2306 /**
2307  * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
2308  * @dev: DRM device
2309  *
2310  * This function can be used as the &drm_driver->lastclose callback for drivers
2311  * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
2312  */
2313 void drm_fb_helper_lastclose(struct drm_device *dev)
2314 {
2315         drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
2316 }
2317 EXPORT_SYMBOL(drm_fb_helper_lastclose);
2318
2319 /**
2320  * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
2321  *                                     helper for fbdev emulation
2322  * @dev: DRM device
2323  *
2324  * This function can be used as the
2325  * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
2326  * need to call drm_fbdev.hotplug_event().
2327  */
2328 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
2329 {
2330         drm_fb_helper_hotplug_event(dev->fb_helper);
2331 }
2332 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);