drivers/gpu/drm/drm_fb_helper.c

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