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 const 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 const 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  *
 454  * This allocates the structures for the fbdev helper with the given limits.
 455  * Note that this won't yet touch the hardware (through the driver interfaces)
 456  * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 457  * to allow driver writes more control over the exact init sequence.
 458  *
 459  * Drivers must call drm_fb_helper_prepare() before calling this function.
 460  *
 461  * RETURNS:
 462  * Zero if everything went ok, nonzero otherwise.
 463  */
 464 int drm_fb_helper_init(struct drm_device *dev,
 465                        struct drm_fb_helper *fb_helper)
 466 {
 467         int ret;
 468
 469         if (!drm_fbdev_emulation) {
 470                 dev->fb_helper = fb_helper;
 471                 return 0;
 472         }
 473
 474         /*
 475          * If this is not the generic fbdev client, initialize a drm_client
 476          * without callbacks so we can use the modesets.
 477          */
 478         if (!fb_helper->client.funcs) {
 479                 ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
 480                 if (ret)
 481                         return ret;
 482         }
 483
 484         dev->fb_helper = fb_helper;
 485
 486         return 0;
 487 }
 488 EXPORT_SYMBOL(drm_fb_helper_init);
 489
 490 /**
 491  * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
 492  * @fb_helper: driver-allocated fbdev helper
 493  *
 494  * A helper to alloc fb_info and the members cmap and apertures. Called
 495  * by the driver within the fb_probe fb_helper callback function. Drivers do not
 496  * need to release the allocated fb_info structure themselves, this is
 497  * automatically done when calling drm_fb_helper_fini().
 498  *
 499  * RETURNS:
 500  * fb_info pointer if things went okay, pointer containing error code
 501  * otherwise
 502  */
 503 struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
 504 {
 505         struct device *dev = fb_helper->dev->dev;
 506         struct fb_info *info;
 507         int ret;
 508
 509         info = framebuffer_alloc(0, dev);
 510         if (!info)
 511                 return ERR_PTR(-ENOMEM);
 512
 513         ret = fb_alloc_cmap(&info->cmap, 256, 0);
 514         if (ret)
 515                 goto err_release;
 516
 517         /*
 518          * TODO: We really should be smarter here and alloc an apperture
 519          * for each IORESOURCE_MEM resource helper->dev->dev has and also
 520          * init the ranges of the appertures based on the resources.
 521          * Note some drivers currently count on there being only 1 empty
 522          * aperture and fill this themselves, these will need to be dealt
 523          * with somehow when fixing this.
 524          */
 525         info->apertures = alloc_apertures(1);
 526         if (!info->apertures) {
 527                 ret = -ENOMEM;
 528                 goto err_free_cmap;
 529         }
 530
 531         fb_helper->fbdev = info;
 532         info->skip_vt_switch = true;
 533
 534         return info;
 535
 536 err_free_cmap:
 537         fb_dealloc_cmap(&info->cmap);
 538 err_release:
 539         framebuffer_release(info);
 540         return ERR_PTR(ret);
 541 }
 542 EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
 543
 544 /**
 545  * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
 546  * @fb_helper: driver-allocated fbdev helper, can be NULL
 547  *
 548  * A wrapper around unregister_framebuffer, to release the fb_info
 549  * framebuffer device. This must be called before releasing all resources for
 550  * @fb_helper by calling drm_fb_helper_fini().
 551  */
 552 void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
 553 {
 554         if (fb_helper && fb_helper->fbdev)
 555                 unregister_framebuffer(fb_helper->fbdev);
 556 }
 557 EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
 558
 559 /**
 560  * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 561  * @fb_helper: driver-allocated fbdev helper, can be NULL
 562  *
 563  * This cleans up all remaining resources associated with @fb_helper.
 564  */
 565 void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 566 {
 567         struct fb_info *info;
 568
 569         if (!fb_helper)
 570                 return;
 571
 572         fb_helper->dev->fb_helper = NULL;
 573
 574         if (!drm_fbdev_emulation)
 575                 return;
 576
 577         cancel_work_sync(&fb_helper->resume_work);
 578         cancel_work_sync(&fb_helper->dirty_work);
 579
 580         info = fb_helper->fbdev;
 581         if (info) {
 582                 if (info->cmap.len)
 583                         fb_dealloc_cmap(&info->cmap);
 584                 framebuffer_release(info);
 585         }
 586         fb_helper->fbdev = NULL;
 587
 588         mutex_lock(&kernel_fb_helper_lock);
 589         if (!list_empty(&fb_helper->kernel_fb_list)) {
 590                 list_del(&fb_helper->kernel_fb_list);
 591                 if (list_empty(&kernel_fb_helper_list))
 592                         unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 593         }
 594         mutex_unlock(&kernel_fb_helper_lock);
 595
 596         mutex_destroy(&fb_helper->lock);
 597
 598         if (!fb_helper->client.funcs)
 599                 drm_client_release(&fb_helper->client);
 600 }
 601 EXPORT_SYMBOL(drm_fb_helper_fini);
 602
 603 static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
 604 {
 605         struct drm_device *dev = fb_helper->dev;
 606         struct drm_framebuffer *fb = fb_helper->fb;
 607
 608         return dev->mode_config.prefer_shadow_fbdev ||
 609                dev->mode_config.prefer_shadow ||
 610                fb->funcs->dirty;
 611 }
 612
 613 static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
 614                                 u32 width, u32 height)
 615 {
 616         struct drm_fb_helper *helper = info->par;
 617         struct drm_clip_rect *clip = &helper->dirty_clip;
 618         unsigned long flags;
 619
 620         if (!drm_fbdev_use_shadow_fb(helper))
 621                 return;
 622
 623         spin_lock_irqsave(&helper->dirty_lock, flags);
 624         clip->x1 = min_t(u32, clip->x1, x);
 625         clip->y1 = min_t(u32, clip->y1, y);
 626         clip->x2 = max_t(u32, clip->x2, x + width);
 627         clip->y2 = max_t(u32, clip->y2, y + height);
 628         spin_unlock_irqrestore(&helper->dirty_lock, flags);
 629
 630         schedule_work(&helper->dirty_work);
 631 }
 632
 633 /**
 634  * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 635  * @info: fb_info struct pointer
 636  * @pagelist: list of dirty mmap framebuffer pages
 637  *
 638  * This function is used as the &fb_deferred_io.deferred_io
 639  * callback function for flushing the fbdev mmap writes.
 640  */
 641 void drm_fb_helper_deferred_io(struct fb_info *info,
 642                                struct list_head *pagelist)
 643 {
 644         unsigned long start, end, min, max;
 645         struct page *page;
 646         u32 y1, y2;
 647
 648         min = ULONG_MAX;
 649         max = 0;
 650         list_for_each_entry(page, pagelist, lru) {
 651                 start = page->index << PAGE_SHIFT;
 652                 end = start + PAGE_SIZE - 1;
 653                 min = min(min, start);
 654                 max = max(max, end);
 655         }
 656
 657         if (min < max) {
 658                 y1 = min / info->fix.line_length;
 659                 y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 660                            info->var.yres);
 661                 drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
 662         }
 663 }
 664 EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 665
 666 /**
 667  * drm_fb_helper_sys_read - wrapper around fb_sys_read
 668  * @info: fb_info struct pointer
 669  * @buf: userspace buffer to read from framebuffer memory
 670  * @count: number of bytes to read from framebuffer memory
 671  * @ppos: read offset within framebuffer memory
 672  *
 673  * A wrapper around fb_sys_read implemented by fbdev core
 674  */
 675 ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 676                                size_t count, loff_t *ppos)
 677 {
 678         return fb_sys_read(info, buf, count, ppos);
 679 }
 680 EXPORT_SYMBOL(drm_fb_helper_sys_read);
 681
 682 /**
 683  * drm_fb_helper_sys_write - wrapper around fb_sys_write
 684  * @info: fb_info struct pointer
 685  * @buf: userspace buffer to write to framebuffer memory
 686  * @count: number of bytes to write to framebuffer memory
 687  * @ppos: write offset within framebuffer memory
 688  *
 689  * A wrapper around fb_sys_write implemented by fbdev core
 690  */
 691 ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 692                                 size_t count, loff_t *ppos)
 693 {
 694         ssize_t ret;
 695
 696         ret = fb_sys_write(info, buf, count, ppos);
 697         if (ret > 0)
 698                 drm_fb_helper_dirty(info, 0, 0, info->var.xres,
 699                                     info->var.yres);
 700
 701         return ret;
 702 }
 703 EXPORT_SYMBOL(drm_fb_helper_sys_write);
 704
 705 /**
 706  * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
 707  * @info: fbdev registered by the helper
 708  * @rect: info about rectangle to fill
 709  *
 710  * A wrapper around sys_fillrect implemented by fbdev core
 711  */
 712 void drm_fb_helper_sys_fillrect(struct fb_info *info,
 713                                 const struct fb_fillrect *rect)
 714 {
 715         sys_fillrect(info, rect);
 716         drm_fb_helper_dirty(info, rect->dx, rect->dy,
 717                             rect->width, rect->height);
 718 }
 719 EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 720
 721 /**
 722  * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
 723  * @info: fbdev registered by the helper
 724  * @area: info about area to copy
 725  *
 726  * A wrapper around sys_copyarea implemented by fbdev core
 727  */
 728 void drm_fb_helper_sys_copyarea(struct fb_info *info,
 729                                 const struct fb_copyarea *area)
 730 {
 731         sys_copyarea(info, area);
 732         drm_fb_helper_dirty(info, area->dx, area->dy,
 733                             area->width, area->height);
 734 }
 735 EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 736
 737 /**
 738  * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
 739  * @info: fbdev registered by the helper
 740  * @image: info about image to blit
 741  *
 742  * A wrapper around sys_imageblit implemented by fbdev core
 743  */
 744 void drm_fb_helper_sys_imageblit(struct fb_info *info,
 745                                  const struct fb_image *image)
 746 {
 747         sys_imageblit(info, image);
 748         drm_fb_helper_dirty(info, image->dx, image->dy,
 749                             image->width, image->height);
 750 }
 751 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 752
 753 /**
 754  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
 755  * @info: fbdev registered by the helper
 756  * @rect: info about rectangle to fill
 757  *
 758  * A wrapper around cfb_fillrect implemented by fbdev core
 759  */
 760 void drm_fb_helper_cfb_fillrect(struct fb_info *info,
 761                                 const struct fb_fillrect *rect)
 762 {
 763         cfb_fillrect(info, rect);
 764         drm_fb_helper_dirty(info, rect->dx, rect->dy,
 765                             rect->width, rect->height);
 766 }
 767 EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
 768
 769 /**
 770  * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
 771  * @info: fbdev registered by the helper
 772  * @area: info about area to copy
 773  *
 774  * A wrapper around cfb_copyarea implemented by fbdev core
 775  */
 776 void drm_fb_helper_cfb_copyarea(struct fb_info *info,
 777                                 const struct fb_copyarea *area)
 778 {
 779         cfb_copyarea(info, area);
 780         drm_fb_helper_dirty(info, area->dx, area->dy,
 781                             area->width, area->height);
 782 }
 783 EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
 784
 785 /**
 786  * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
 787  * @info: fbdev registered by the helper
 788  * @image: info about image to blit
 789  *
 790  * A wrapper around cfb_imageblit implemented by fbdev core
 791  */
 792 void drm_fb_helper_cfb_imageblit(struct fb_info *info,
 793                                  const struct fb_image *image)
 794 {
 795         cfb_imageblit(info, image);
 796         drm_fb_helper_dirty(info, image->dx, image->dy,
 797                             image->width, image->height);
 798 }
 799 EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
 800
 801 /**
 802  * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
 803  * @fb_helper: driver-allocated fbdev helper, can be NULL
 804  * @suspend: whether to suspend or resume
 805  *
 806  * A wrapper around fb_set_suspend implemented by fbdev core.
 807  * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
 808  * the lock yourself
 809  */
 810 void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
 811 {
 812         if (fb_helper && fb_helper->fbdev)
 813                 fb_set_suspend(fb_helper->fbdev, suspend);
 814 }
 815 EXPORT_SYMBOL(drm_fb_helper_set_suspend);
 816
 817 /**
 818  * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
 819  *                                      takes the console lock
 820  * @fb_helper: driver-allocated fbdev helper, can be NULL
 821  * @suspend: whether to suspend or resume
 822  *
 823  * A wrapper around fb_set_suspend() that takes the console lock. If the lock
 824  * isn't available on resume, a worker is tasked with waiting for the lock
 825  * to become available. The console lock can be pretty contented on resume
 826  * due to all the printk activity.
 827  *
 828  * This function can be called multiple times with the same state since
 829  * &fb_info.state is checked to see if fbdev is running or not before locking.
 830  *
 831  * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
 832  */
 833 void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
 834                                         bool suspend)
 835 {
 836         if (!fb_helper || !fb_helper->fbdev)
 837                 return;
 838
 839         /* make sure there's no pending/ongoing resume */
 840         flush_work(&fb_helper->resume_work);
 841
 842         if (suspend) {
 843                 if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
 844                         return;
 845
 846                 console_lock();
 847
 848         } else {
 849                 if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
 850                         return;
 851
 852                 if (!console_trylock()) {
 853                         schedule_work(&fb_helper->resume_work);
 854                         return;
 855                 }
 856         }
 857
 858         fb_set_suspend(fb_helper->fbdev, suspend);
 859         console_unlock();
 860 }
 861 EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
 862
 863 static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 864 {
 865         u32 *palette = (u32 *)info->pseudo_palette;
 866         int i;
 867
 868         if (cmap->start + cmap->len > 16)
 869                 return -EINVAL;
 870
 871         for (i = 0; i < cmap->len; ++i) {
 872                 u16 red = cmap->red[i];
 873                 u16 green = cmap->green[i];
 874                 u16 blue = cmap->blue[i];
 875                 u32 value;
 876
 877                 red >>= 16 - info->var.red.length;
 878                 green >>= 16 - info->var.green.length;
 879                 blue >>= 16 - info->var.blue.length;
 880                 value = (red << info->var.red.offset) |
 881                         (green << info->var.green.offset) |
 882                         (blue << info->var.blue.offset);
 883                 if (info->var.transp.length > 0) {
 884                         u32 mask = (1 << info->var.transp.length) - 1;
 885
 886                         mask <<= info->var.transp.offset;
 887                         value |= mask;
 888                 }
 889                 palette[cmap->start + i] = value;
 890         }
 891
 892         return 0;
 893 }
 894
 895 static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
 896 {
 897         struct drm_fb_helper *fb_helper = info->par;
 898         struct drm_mode_set *modeset;
 899         struct drm_crtc *crtc;
 900         u16 *r, *g, *b;
 901         int ret = 0;
 902
 903         drm_modeset_lock_all(fb_helper->dev);
 904         drm_client_for_each_modeset(modeset, &fb_helper->client) {
 905                 crtc = modeset->crtc;
 906                 if (!crtc->funcs->gamma_set || !crtc->gamma_size)
 907                         return -EINVAL;
 908
 909                 if (cmap->start + cmap->len > crtc->gamma_size)
 910                         return -EINVAL;
 911
 912                 r = crtc->gamma_store;
 913                 g = r + crtc->gamma_size;
 914                 b = g + crtc->gamma_size;
 915
 916                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
 917                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
 918                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
 919
 920                 ret = crtc->funcs->gamma_set(crtc, r, g, b,
 921                                              crtc->gamma_size, NULL);
 922                 if (ret)
 923                         return ret;
 924         }
 925         drm_modeset_unlock_all(fb_helper->dev);
 926
 927         return ret;
 928 }
 929
 930 static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
 931                                                        struct fb_cmap *cmap)
 932 {
 933         struct drm_device *dev = crtc->dev;
 934         struct drm_property_blob *gamma_lut;
 935         struct drm_color_lut *lut;
 936         int size = crtc->gamma_size;
 937         int i;
 938
 939         if (!size || cmap->start + cmap->len > size)
 940                 return ERR_PTR(-EINVAL);
 941
 942         gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
 943         if (IS_ERR(gamma_lut))
 944                 return gamma_lut;
 945
 946         lut = gamma_lut->data;
 947         if (cmap->start || cmap->len != size) {
 948                 u16 *r = crtc->gamma_store;
 949                 u16 *g = r + crtc->gamma_size;
 950                 u16 *b = g + crtc->gamma_size;
 951
 952                 for (i = 0; i < cmap->start; i++) {
 953                         lut[i].red = r[i];
 954                         lut[i].green = g[i];
 955                         lut[i].blue = b[i];
 956                 }
 957                 for (i = cmap->start + cmap->len; i < size; i++) {
 958                         lut[i].red = r[i];
 959                         lut[i].green = g[i];
 960                         lut[i].blue = b[i];
 961                 }
 962         }
 963
 964         for (i = 0; i < cmap->len; i++) {
 965                 lut[cmap->start + i].red = cmap->red[i];
 966                 lut[cmap->start + i].green = cmap->green[i];
 967                 lut[cmap->start + i].blue = cmap->blue[i];
 968         }
 969
 970         return gamma_lut;
 971 }
 972
 973 static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
 974 {
 975         struct drm_fb_helper *fb_helper = info->par;
 976         struct drm_device *dev = fb_helper->dev;
 977         struct drm_property_blob *gamma_lut = NULL;
 978         struct drm_modeset_acquire_ctx ctx;
 979         struct drm_crtc_state *crtc_state;
 980         struct drm_atomic_state *state;
 981         struct drm_mode_set *modeset;
 982         struct drm_crtc *crtc;
 983         u16 *r, *g, *b;
 984         bool replaced;
 985         int ret = 0;
 986
 987         drm_modeset_acquire_init(&ctx, 0);
 988
 989         state = drm_atomic_state_alloc(dev);
 990         if (!state) {
 991                 ret = -ENOMEM;
 992                 goto out_ctx;
 993         }
 994
 995         state->acquire_ctx = &ctx;
 996 retry:
 997         drm_client_for_each_modeset(modeset, &fb_helper->client) {
 998                 crtc = modeset->crtc;
 999
1000                 if (!gamma_lut)
1001                         gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1002                 if (IS_ERR(gamma_lut)) {
1003                         ret = PTR_ERR(gamma_lut);
1004                         gamma_lut = NULL;
1005                         goto out_state;
1006                 }
1007
1008                 crtc_state = drm_atomic_get_crtc_state(state, crtc);
1009                 if (IS_ERR(crtc_state)) {
1010                         ret = PTR_ERR(crtc_state);
1011                         goto out_state;
1012                 }
1013
1014                 replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1015                                                       NULL);
1016                 replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1017                 replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1018                                                       gamma_lut);
1019                 crtc_state->color_mgmt_changed |= replaced;
1020         }
1021
1022         ret = drm_atomic_commit(state);
1023         if (ret)
1024                 goto out_state;
1025
1026         drm_client_for_each_modeset(modeset, &fb_helper->client) {
1027                 crtc = modeset->crtc;
1028
1029                 r = crtc->gamma_store;
1030                 g = r + crtc->gamma_size;
1031                 b = g + crtc->gamma_size;
1032
1033                 memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1034                 memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1035                 memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1036         }
1037
1038 out_state:
1039         if (ret == -EDEADLK)
1040                 goto backoff;
1041
1042         drm_property_blob_put(gamma_lut);
1043         drm_atomic_state_put(state);
1044 out_ctx:
1045         drm_modeset_drop_locks(&ctx);
1046         drm_modeset_acquire_fini(&ctx);
1047
1048         return ret;
1049
1050 backoff:
1051         drm_atomic_state_clear(state);
1052         drm_modeset_backoff(&ctx);
1053         goto retry;
1054 }
1055
1056 /**
1057  * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1058  * @cmap: cmap to set
1059  * @info: fbdev registered by the helper
1060  */
1061 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1062 {
1063         struct drm_fb_helper *fb_helper = info->par;
1064         struct drm_device *dev = fb_helper->dev;
1065         int ret;
1066
1067         if (oops_in_progress)
1068                 return -EBUSY;
1069
1070         mutex_lock(&fb_helper->lock);
1071
1072         if (!drm_master_internal_acquire(dev)) {
1073                 ret = -EBUSY;
1074                 goto unlock;
1075         }
1076
1077         mutex_lock(&fb_helper->client.modeset_mutex);
1078         if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1079                 ret = setcmap_pseudo_palette(cmap, info);
1080         else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1081                 ret = setcmap_atomic(cmap, info);
1082         else
1083                 ret = setcmap_legacy(cmap, info);
1084         mutex_unlock(&fb_helper->client.modeset_mutex);
1085
1086         drm_master_internal_release(dev);
1087 unlock:
1088         mutex_unlock(&fb_helper->lock);
1089
1090         return ret;
1091 }
1092 EXPORT_SYMBOL(drm_fb_helper_setcmap);
1093
1094 /**
1095  * drm_fb_helper_ioctl - legacy ioctl implementation
1096  * @info: fbdev registered by the helper
1097  * @cmd: ioctl command
1098  * @arg: ioctl argument
1099  *
1100  * A helper to implement the standard fbdev ioctl. Only
1101  * FBIO_WAITFORVSYNC is implemented for now.
1102  */
1103 int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1104                         unsigned long arg)
1105 {
1106         struct drm_fb_helper *fb_helper = info->par;
1107         struct drm_device *dev = fb_helper->dev;
1108         struct drm_crtc *crtc;
1109         int ret = 0;
1110
1111         mutex_lock(&fb_helper->lock);
1112         if (!drm_master_internal_acquire(dev)) {
1113                 ret = -EBUSY;
1114                 goto unlock;
1115         }
1116
1117         switch (cmd) {
1118         case FBIO_WAITFORVSYNC:
1119                 /*
1120                  * Only consider the first CRTC.
1121                  *
1122                  * This ioctl is supposed to take the CRTC number as
1123                  * an argument, but in fbdev times, what that number
1124                  * was supposed to be was quite unclear, different
1125                  * drivers were passing that argument differently
1126                  * (some by reference, some by value), and most of the
1127                  * userspace applications were just hardcoding 0 as an
1128                  * argument.
1129                  *
1130                  * The first CRTC should be the integrated panel on
1131                  * most drivers, so this is the best choice we can
1132                  * make. If we're not smart enough here, one should
1133                  * just consider switch the userspace to KMS.
1134                  */
1135                 crtc = fb_helper->client.modesets[0].crtc;
1136
1137                 /*
1138                  * Only wait for a vblank event if the CRTC is
1139                  * enabled, otherwise just don't do anythintg,
1140                  * not even report an error.
1141                  */
1142                 ret = drm_crtc_vblank_get(crtc);
1143                 if (!ret) {
1144                         drm_crtc_wait_one_vblank(crtc);
1145                         drm_crtc_vblank_put(crtc);
1146                 }
1147
1148                 ret = 0;
1149                 break;
1150         default:
1151                 ret = -ENOTTY;
1152         }
1153
1154         drm_master_internal_release(dev);
1155 unlock:
1156         mutex_unlock(&fb_helper->lock);
1157         return ret;
1158 }
1159 EXPORT_SYMBOL(drm_fb_helper_ioctl);
1160
1161 static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1162                                       const struct fb_var_screeninfo *var_2)
1163 {
1164         return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1165                var_1->grayscale == var_2->grayscale &&
1166                var_1->red.offset == var_2->red.offset &&
1167                var_1->red.length == var_2->red.length &&
1168                var_1->red.msb_right == var_2->red.msb_right &&
1169                var_1->green.offset == var_2->green.offset &&
1170                var_1->green.length == var_2->green.length &&
1171                var_1->green.msb_right == var_2->green.msb_right &&
1172                var_1->blue.offset == var_2->blue.offset &&
1173                var_1->blue.length == var_2->blue.length &&
1174                var_1->blue.msb_right == var_2->blue.msb_right &&
1175                var_1->transp.offset == var_2->transp.offset &&
1176                var_1->transp.length == var_2->transp.length &&
1177                var_1->transp.msb_right == var_2->transp.msb_right;
1178 }
1179
1180 static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1181                                          u8 depth)
1182 {
1183         switch (depth) {
1184         case 8:
1185                 var->red.offset = 0;
1186                 var->green.offset = 0;
1187                 var->blue.offset = 0;
1188                 var->red.length = 8; /* 8bit DAC */
1189                 var->green.length = 8;
1190                 var->blue.length = 8;
1191                 var->transp.offset = 0;
1192                 var->transp.length = 0;
1193                 break;
1194         case 15:
1195                 var->red.offset = 10;
1196                 var->green.offset = 5;
1197                 var->blue.offset = 0;
1198                 var->red.length = 5;
1199                 var->green.length = 5;
1200                 var->blue.length = 5;
1201                 var->transp.offset = 15;
1202                 var->transp.length = 1;
1203                 break;
1204         case 16:
1205                 var->red.offset = 11;
1206                 var->green.offset = 5;
1207                 var->blue.offset = 0;
1208                 var->red.length = 5;
1209                 var->green.length = 6;
1210                 var->blue.length = 5;
1211                 var->transp.offset = 0;
1212                 break;
1213         case 24:
1214                 var->red.offset = 16;
1215                 var->green.offset = 8;
1216                 var->blue.offset = 0;
1217                 var->red.length = 8;
1218                 var->green.length = 8;
1219                 var->blue.length = 8;
1220                 var->transp.offset = 0;
1221                 var->transp.length = 0;
1222                 break;
1223         case 32:
1224                 var->red.offset = 16;
1225                 var->green.offset = 8;
1226                 var->blue.offset = 0;
1227                 var->red.length = 8;
1228                 var->green.length = 8;
1229                 var->blue.length = 8;
1230                 var->transp.offset = 24;
1231                 var->transp.length = 8;
1232                 break;
1233         default:
1234                 break;
1235         }
1236 }
1237
1238 /**
1239  * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1240  * @var: screeninfo to check
1241  * @info: fbdev registered by the helper
1242  */
1243 int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1244                             struct fb_info *info)
1245 {
1246         struct drm_fb_helper *fb_helper = info->par;
1247         struct drm_framebuffer *fb = fb_helper->fb;
1248         struct drm_device *dev = fb_helper->dev;
1249
1250         if (in_dbg_master())
1251                 return -EINVAL;
1252
1253         if (var->pixclock != 0) {
1254                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1255                 var->pixclock = 0;
1256         }
1257
1258         if ((drm_format_info_block_width(fb->format, 0) > 1) ||
1259             (drm_format_info_block_height(fb->format, 0) > 1))
1260                 return -EINVAL;
1261
1262         /*
1263          * Changes struct fb_var_screeninfo are currently not pushed back
1264          * to KMS, hence fail if different settings are requested.
1265          */
1266         if (var->bits_per_pixel > fb->format->cpp[0] * 8 ||
1267             var->xres > fb->width || var->yres > fb->height ||
1268             var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1269                 drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1270                           "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1271                           var->xres, var->yres, var->bits_per_pixel,
1272                           var->xres_virtual, var->yres_virtual,
1273                           fb->width, fb->height, fb->format->cpp[0] * 8);
1274                 return -EINVAL;
1275         }
1276
1277         /*
1278          * Workaround for SDL 1.2, which is known to be setting all pixel format
1279          * fields values to zero in some cases. We treat this situation as a
1280          * kind of "use some reasonable autodetected values".
1281          */
1282         if (!var->red.offset     && !var->green.offset    &&
1283             !var->blue.offset    && !var->transp.offset   &&
1284             !var->red.length     && !var->green.length    &&
1285             !var->blue.length    && !var->transp.length   &&
1286             !var->red.msb_right  && !var->green.msb_right &&
1287             !var->blue.msb_right && !var->transp.msb_right) {
1288                 drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
1289         }
1290
1291         /*
1292          * Likewise, bits_per_pixel should be rounded up to a supported value.
1293          */
1294         var->bits_per_pixel = fb->format->cpp[0] * 8;
1295
1296         /*
1297          * drm fbdev emulation doesn't support changing the pixel format at all,
1298          * so reject all pixel format changing requests.
1299          */
1300         if (!drm_fb_pixel_format_equal(var, &info->var)) {
1301                 drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1302                 return -EINVAL;
1303         }
1304
1305         return 0;
1306 }
1307 EXPORT_SYMBOL(drm_fb_helper_check_var);
1308
1309 /**
1310  * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1311  * @info: fbdev registered by the helper
1312  *
1313  * This will let fbcon do the mode init and is called at initialization time by
1314  * the fbdev core when registering the driver, and later on through the hotplug
1315  * callback.
1316  */
1317 int drm_fb_helper_set_par(struct fb_info *info)
1318 {
1319         struct drm_fb_helper *fb_helper = info->par;
1320         struct fb_var_screeninfo *var = &info->var;
1321
1322         if (oops_in_progress)
1323                 return -EBUSY;
1324
1325         if (var->pixclock != 0) {
1326                 drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1327                 return -EINVAL;
1328         }
1329
1330         drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
1331
1332         return 0;
1333 }
1334 EXPORT_SYMBOL(drm_fb_helper_set_par);
1335
1336 static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1337 {
1338         struct drm_mode_set *mode_set;
1339
1340         mutex_lock(&fb_helper->client.modeset_mutex);
1341         drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1342                 mode_set->x = x;
1343                 mode_set->y = y;
1344         }
1345         mutex_unlock(&fb_helper->client.modeset_mutex);
1346 }
1347
1348 static int pan_display_atomic(struct fb_var_screeninfo *var,
1349                               struct fb_info *info)
1350 {
1351         struct drm_fb_helper *fb_helper = info->par;
1352         int ret;
1353
1354         pan_set(fb_helper, var->xoffset, var->yoffset);
1355
1356         ret = drm_client_modeset_commit_locked(&fb_helper->client);
1357         if (!ret) {
1358                 info->var.xoffset = var->xoffset;
1359                 info->var.yoffset = var->yoffset;
1360         } else
1361                 pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1362
1363         return ret;
1364 }
1365
1366 static int pan_display_legacy(struct fb_var_screeninfo *var,
1367                               struct fb_info *info)
1368 {
1369         struct drm_fb_helper *fb_helper = info->par;
1370         struct drm_client_dev *client = &fb_helper->client;
1371         struct drm_mode_set *modeset;
1372         int ret = 0;
1373
1374         mutex_lock(&client->modeset_mutex);
1375         drm_modeset_lock_all(fb_helper->dev);
1376         drm_client_for_each_modeset(modeset, client) {
1377                 modeset->x = var->xoffset;
1378                 modeset->y = var->yoffset;
1379
1380                 if (modeset->num_connectors) {
1381                         ret = drm_mode_set_config_internal(modeset);
1382                         if (!ret) {
1383                                 info->var.xoffset = var->xoffset;
1384                                 info->var.yoffset = var->yoffset;
1385                         }
1386                 }
1387         }
1388         drm_modeset_unlock_all(fb_helper->dev);
1389         mutex_unlock(&client->modeset_mutex);
1390
1391         return ret;
1392 }
1393
1394 /**
1395  * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1396  * @var: updated screen information
1397  * @info: fbdev registered by the helper
1398  */
1399 int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1400                               struct fb_info *info)
1401 {
1402         struct drm_fb_helper *fb_helper = info->par;
1403         struct drm_device *dev = fb_helper->dev;
1404         int ret;
1405
1406         if (oops_in_progress)
1407                 return -EBUSY;
1408
1409         mutex_lock(&fb_helper->lock);
1410         if (!drm_master_internal_acquire(dev)) {
1411                 ret = -EBUSY;
1412                 goto unlock;
1413         }
1414
1415         if (drm_drv_uses_atomic_modeset(dev))
1416                 ret = pan_display_atomic(var, info);
1417         else
1418                 ret = pan_display_legacy(var, info);
1419
1420         drm_master_internal_release(dev);
1421 unlock:
1422         mutex_unlock(&fb_helper->lock);
1423
1424         return ret;
1425 }
1426 EXPORT_SYMBOL(drm_fb_helper_pan_display);
1427
1428 /*
1429  * Allocates the backing storage and sets up the fbdev info structure through
1430  * the ->fb_probe callback.
1431  */
1432 static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1433                                          int preferred_bpp)
1434 {
1435         struct drm_client_dev *client = &fb_helper->client;
1436         struct drm_device *dev = fb_helper->dev;
1437         int ret = 0;
1438         int crtc_count = 0;
1439         struct drm_connector_list_iter conn_iter;
1440         struct drm_fb_helper_surface_size sizes;
1441         struct drm_connector *connector;
1442         struct drm_mode_set *mode_set;
1443         int best_depth = 0;
1444
1445         memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1446         sizes.surface_depth = 24;
1447         sizes.surface_bpp = 32;
1448         sizes.fb_width = (u32)-1;
1449         sizes.fb_height = (u32)-1;
1450
1451         /*
1452          * If driver picks 8 or 16 by default use that for both depth/bpp
1453          * to begin with
1454          */
1455         if (preferred_bpp != sizes.surface_bpp)
1456                 sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1457
1458         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1459         drm_client_for_each_connector_iter(connector, &conn_iter) {
1460                 struct drm_cmdline_mode *cmdline_mode;
1461
1462                 cmdline_mode = &connector->cmdline_mode;
1463
1464                 if (cmdline_mode->bpp_specified) {
1465                         switch (cmdline_mode->bpp) {
1466                         case 8:
1467                                 sizes.surface_depth = sizes.surface_bpp = 8;
1468                                 break;
1469                         case 15:
1470                                 sizes.surface_depth = 15;
1471                                 sizes.surface_bpp = 16;
1472                                 break;
1473                         case 16:
1474                                 sizes.surface_depth = sizes.surface_bpp = 16;
1475                                 break;
1476                         case 24:
1477                                 sizes.surface_depth = sizes.surface_bpp = 24;
1478                                 break;
1479                         case 32:
1480                                 sizes.surface_depth = 24;
1481                                 sizes.surface_bpp = 32;
1482                                 break;
1483                         }
1484                         break;
1485                 }
1486         }
1487         drm_connector_list_iter_end(&conn_iter);
1488
1489         /*
1490          * If we run into a situation where, for example, the primary plane
1491          * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1492          * 16) we need to scale down the depth of the sizes we request.
1493          */
1494         mutex_lock(&client->modeset_mutex);
1495         drm_client_for_each_modeset(mode_set, client) {
1496                 struct drm_crtc *crtc = mode_set->crtc;
1497                 struct drm_plane *plane = crtc->primary;
1498                 int j;
1499
1500                 drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1501
1502                 for (j = 0; j < plane->format_count; j++) {
1503                         const struct drm_format_info *fmt;
1504
1505                         fmt = drm_format_info(plane->format_types[j]);
1506
1507                         /*
1508                          * Do not consider YUV or other complicated formats
1509                          * for framebuffers. This means only legacy formats
1510                          * are supported (fmt->depth is a legacy field) but
1511                          * the framebuffer emulation can only deal with such
1512                          * formats, specifically RGB/BGA formats.
1513                          */
1514                         if (fmt->depth == 0)
1515                                 continue;
1516
1517                         /* We found a perfect fit, great */
1518                         if (fmt->depth == sizes.surface_depth) {
1519                                 best_depth = fmt->depth;
1520                                 break;
1521                         }
1522
1523                         /* Skip depths above what we're looking for */
1524                         if (fmt->depth > sizes.surface_depth)
1525                                 continue;
1526
1527                         /* Best depth found so far */
1528                         if (fmt->depth > best_depth)
1529                                 best_depth = fmt->depth;
1530                 }
1531         }
1532         if (sizes.surface_depth != best_depth && best_depth) {
1533                 drm_info(dev, "requested bpp %d, scaled depth down to %d",
1534                          sizes.surface_bpp, best_depth);
1535                 sizes.surface_depth = best_depth;
1536         }
1537
1538         /* first up get a count of crtcs now in use and new min/maxes width/heights */
1539         crtc_count = 0;
1540         drm_client_for_each_modeset(mode_set, client) {
1541                 struct drm_display_mode *desired_mode;
1542                 int x, y, j;
1543                 /* in case of tile group, are we the last tile vert or horiz?
1544                  * If no tile group you are always the last one both vertically
1545                  * and horizontally
1546                  */
1547                 bool lastv = true, lasth = true;
1548
1549                 desired_mode = mode_set->mode;
1550
1551                 if (!desired_mode)
1552                         continue;
1553
1554                 crtc_count++;
1555
1556                 x = mode_set->x;
1557                 y = mode_set->y;
1558
1559                 sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1560                 sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1561
1562                 for (j = 0; j < mode_set->num_connectors; j++) {
1563                         struct drm_connector *connector = mode_set->connectors[j];
1564
1565                         if (connector->has_tile &&
1566                             desired_mode->hdisplay == connector->tile_h_size &&
1567                             desired_mode->vdisplay == connector->tile_v_size) {
1568                                 lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1569                                 lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1570                                 /* cloning to multiple tiles is just crazy-talk, so: */
1571                                 break;
1572                         }
1573                 }
1574
1575                 if (lasth)
1576                         sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1577                 if (lastv)
1578                         sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1579         }
1580         mutex_unlock(&client->modeset_mutex);
1581
1582         if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1583                 drm_info(dev, "Cannot find any crtc or sizes\n");
1584
1585                 /* First time: disable all crtc's.. */
1586                 if (!fb_helper->deferred_setup)
1587                         drm_client_modeset_commit(client);
1588                 return -EAGAIN;
1589         }
1590
1591         /* Handle our overallocation */
1592         sizes.surface_height *= drm_fbdev_overalloc;
1593         sizes.surface_height /= 100;
1594
1595         /* push down into drivers */
1596         ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1597         if (ret < 0)
1598                 return ret;
1599
1600         strcpy(fb_helper->fb->comm, "[fbcon]");
1601         return 0;
1602 }
1603
1604 static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1605                                    uint32_t depth)
1606 {
1607         info->fix.type = FB_TYPE_PACKED_PIXELS;
1608         info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1609                 FB_VISUAL_TRUECOLOR;
1610         info->fix.mmio_start = 0;
1611         info->fix.mmio_len = 0;
1612         info->fix.type_aux = 0;
1613         info->fix.xpanstep = 1; /* doing it in hw */
1614         info->fix.ypanstep = 1; /* doing it in hw */
1615         info->fix.ywrapstep = 0;
1616         info->fix.accel = FB_ACCEL_NONE;
1617
1618         info->fix.line_length = pitch;
1619 }
1620
1621 static void drm_fb_helper_fill_var(struct fb_info *info,
1622                                    struct drm_fb_helper *fb_helper,
1623                                    uint32_t fb_width, uint32_t fb_height)
1624 {
1625         struct drm_framebuffer *fb = fb_helper->fb;
1626
1627         WARN_ON((drm_format_info_block_width(fb->format, 0) > 1) ||
1628                 (drm_format_info_block_height(fb->format, 0) > 1));
1629         info->pseudo_palette = fb_helper->pseudo_palette;
1630         info->var.xres_virtual = fb->width;
1631         info->var.yres_virtual = fb->height;
1632         info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1633         info->var.accel_flags = FB_ACCELF_TEXT;
1634         info->var.xoffset = 0;
1635         info->var.yoffset = 0;
1636         info->var.activate = FB_ACTIVATE_NOW;
1637
1638         drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
1639
1640         info->var.xres = fb_width;
1641         info->var.yres = fb_height;
1642 }
1643
1644 /**
1645  * drm_fb_helper_fill_info - initializes fbdev information
1646  * @info: fbdev instance to set up
1647  * @fb_helper: fb helper instance to use as template
1648  * @sizes: describes fbdev size and scanout surface size
1649  *
1650  * Sets up the variable and fixed fbdev metainformation from the given fb helper
1651  * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1652  *
1653  * Drivers should call this (or their equivalent setup code) from their
1654  * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1655  * backing storage framebuffer.
1656  */
1657 void drm_fb_helper_fill_info(struct fb_info *info,
1658                              struct drm_fb_helper *fb_helper,
1659                              struct drm_fb_helper_surface_size *sizes)
1660 {
1661         struct drm_framebuffer *fb = fb_helper->fb;
1662
1663         drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
1664         drm_fb_helper_fill_var(info, fb_helper,
1665                                sizes->fb_width, sizes->fb_height);
1666
1667         info->par = fb_helper;
1668         snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
1669                  fb_helper->dev->driver->name);
1670
1671 }
1672 EXPORT_SYMBOL(drm_fb_helper_fill_info);
1673
1674 /*
1675  * This is a continuation of drm_setup_crtcs() that sets up anything related
1676  * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1677  * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
1678  * So, any setup that touches those fields needs to be done here instead of in
1679  * drm_setup_crtcs().
1680  */
1681 static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1682 {
1683         struct drm_client_dev *client = &fb_helper->client;
1684         struct drm_connector_list_iter conn_iter;
1685         struct fb_info *info = fb_helper->fbdev;
1686         unsigned int rotation, sw_rotations = 0;
1687         struct drm_connector *connector;
1688         struct drm_mode_set *modeset;
1689
1690         mutex_lock(&client->modeset_mutex);
1691         drm_client_for_each_modeset(modeset, client) {
1692                 if (!modeset->num_connectors)
1693                         continue;
1694
1695                 modeset->fb = fb_helper->fb;
1696
1697                 if (drm_client_rotation(modeset, &rotation))
1698                         /* Rotating in hardware, fbcon should not rotate */
1699                         sw_rotations |= DRM_MODE_ROTATE_0;
1700                 else
1701                         sw_rotations |= rotation;
1702         }
1703         mutex_unlock(&client->modeset_mutex);
1704
1705         drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1706         drm_client_for_each_connector_iter(connector, &conn_iter) {
1707
1708                 /* use first connected connector for the physical dimensions */
1709                 if (connector->status == connector_status_connected) {
1710                         info->var.width = connector->display_info.width_mm;
1711                         info->var.height = connector->display_info.height_mm;
1712                         break;
1713                 }
1714         }
1715         drm_connector_list_iter_end(&conn_iter);
1716
1717         switch (sw_rotations) {
1718         case DRM_MODE_ROTATE_0:
1719                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1720                 break;
1721         case DRM_MODE_ROTATE_90:
1722                 info->fbcon_rotate_hint = FB_ROTATE_CCW;
1723                 break;
1724         case DRM_MODE_ROTATE_180:
1725                 info->fbcon_rotate_hint = FB_ROTATE_UD;
1726                 break;
1727         case DRM_MODE_ROTATE_270:
1728                 info->fbcon_rotate_hint = FB_ROTATE_CW;
1729                 break;
1730         default:
1731                 /*
1732                  * Multiple bits are set / multiple rotations requested
1733                  * fbcon cannot handle separate rotation settings per
1734                  * output, so fallback to unrotated.
1735                  */
1736                 info->fbcon_rotate_hint = FB_ROTATE_UR;
1737         }
1738 }
1739
1740 /* Note: Drops fb_helper->lock before returning. */
1741 static int
1742 __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
1743                                           int bpp_sel)
1744 {
1745         struct drm_device *dev = fb_helper->dev;
1746         struct fb_info *info;
1747         unsigned int width, height;
1748         int ret;
1749
1750         width = dev->mode_config.max_width;
1751         height = dev->mode_config.max_height;
1752
1753         drm_client_modeset_probe(&fb_helper->client, width, height);
1754         ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
1755         if (ret < 0) {
1756                 if (ret == -EAGAIN) {
1757                         fb_helper->preferred_bpp = bpp_sel;
1758                         fb_helper->deferred_setup = true;
1759                         ret = 0;
1760                 }
1761                 mutex_unlock(&fb_helper->lock);
1762
1763                 return ret;
1764         }
1765         drm_setup_crtcs_fb(fb_helper);
1766
1767         fb_helper->deferred_setup = false;
1768
1769         info = fb_helper->fbdev;
1770         info->var.pixclock = 0;
1771         /* Shamelessly allow physical address leaking to userspace */
1772 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1773         if (!drm_leak_fbdev_smem)
1774 #endif
1775                 /* don't leak any physical addresses to userspace */
1776                 info->flags |= FBINFO_HIDE_SMEM_START;
1777
1778         /* Need to drop locks to avoid recursive deadlock in
1779          * register_framebuffer. This is ok because the only thing left to do is
1780          * register the fbdev emulation instance in kernel_fb_helper_list. */
1781         mutex_unlock(&fb_helper->lock);
1782
1783         ret = register_framebuffer(info);
1784         if (ret < 0)
1785                 return ret;
1786
1787         drm_info(dev, "fb%d: %s frame buffer device\n",
1788                  info->node, info->fix.id);
1789
1790         mutex_lock(&kernel_fb_helper_lock);
1791         if (list_empty(&kernel_fb_helper_list))
1792                 register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
1793
1794         list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
1795         mutex_unlock(&kernel_fb_helper_lock);
1796
1797         return 0;
1798 }
1799
1800 /**
1801  * drm_fb_helper_initial_config - setup a sane initial connector configuration
1802  * @fb_helper: fb_helper device struct
1803  * @bpp_sel: bpp value to use for the framebuffer configuration
1804  *
1805  * Scans the CRTCs and connectors and tries to put together an initial setup.
1806  * At the moment, this is a cloned configuration across all heads with
1807  * a new framebuffer object as the backing store.
1808  *
1809  * Note that this also registers the fbdev and so allows userspace to call into
1810  * the driver through the fbdev interfaces.
1811  *
1812  * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1813  * to let the driver allocate and initialize the fbdev info structure and the
1814  * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1815  * as a helper to setup simple default values for the fbdev info structure.
1816  *
1817  * HANG DEBUGGING:
1818  *
1819  * When you have fbcon support built-in or already loaded, this function will do
1820  * a full modeset to setup the fbdev console. Due to locking misdesign in the
1821  * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1822  * console_lock. Until console_unlock is called no dmesg lines will be sent out
1823  * to consoles, not even serial console. This means when your driver crashes,
1824  * you will see absolutely nothing else but a system stuck in this function,
1825  * with no further output. Any kind of printk() you place within your own driver
1826  * or in the drm core modeset code will also never show up.
1827  *
1828  * Standard debug practice is to run the fbcon setup without taking the
1829  * console_lock as a hack, to be able to see backtraces and crashes on the
1830  * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1831  * cmdline option.
1832  *
1833  * The other option is to just disable fbdev emulation since very likely the
1834  * first modeset from userspace will crash in the same way, and is even easier
1835  * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1836  * kernel cmdline option.
1837  *
1838  * RETURNS:
1839  * Zero if everything went ok, nonzero otherwise.
1840  */
1841 int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
1842 {
1843         int ret;
1844
1845         if (!drm_fbdev_emulation)
1846                 return 0;
1847
1848         mutex_lock(&fb_helper->lock);
1849         ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
1850
1851         return ret;
1852 }
1853 EXPORT_SYMBOL(drm_fb_helper_initial_config);
1854
1855 /**
1856  * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1857  *                               probing all the outputs attached to the fb
1858  * @fb_helper: driver-allocated fbdev helper, can be NULL
1859  *
1860  * Scan the connectors attached to the fb_helper and try to put together a
1861  * setup after notification of a change in output configuration.
1862  *
1863  * Called at runtime, takes the mode config locks to be able to check/change the
1864  * modeset configuration. Must be run from process context (which usually means
1865  * either the output polling work or a work item launched from the driver's
1866  * hotplug interrupt).
1867  *
1868  * Note that drivers may call this even before calling
1869  * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1870  * for a race-free fbcon setup and will make sure that the fbdev emulation will
1871  * not miss any hotplug events.
1872  *
1873  * RETURNS:
1874  * 0 on success and a non-zero error code otherwise.
1875  */
1876 int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1877 {
1878         int err = 0;
1879
1880         if (!drm_fbdev_emulation || !fb_helper)
1881                 return 0;
1882
1883         mutex_lock(&fb_helper->lock);
1884         if (fb_helper->deferred_setup) {
1885                 err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
1886                                 fb_helper->preferred_bpp);
1887                 return err;
1888         }
1889
1890         if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
1891                 fb_helper->delayed_hotplug = true;
1892                 mutex_unlock(&fb_helper->lock);
1893                 return err;
1894         }
1895
1896         drm_master_internal_release(fb_helper->dev);
1897
1898         drm_dbg_kms(fb_helper->dev, "\n");
1899
1900         drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
1901         drm_setup_crtcs_fb(fb_helper);
1902         mutex_unlock(&fb_helper->lock);
1903
1904         drm_fb_helper_set_par(fb_helper->fbdev);
1905
1906         return 0;
1907 }
1908 EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1909
1910 /**
1911  * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
1912  * @dev: DRM device
1913  *
1914  * This function can be used as the &drm_driver->lastclose callback for drivers
1915  * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
1916  */
1917 void drm_fb_helper_lastclose(struct drm_device *dev)
1918 {
1919         drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
1920 }
1921 EXPORT_SYMBOL(drm_fb_helper_lastclose);
1922
1923 /**
1924  * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
1925  *                                     helper for fbdev emulation
1926  * @dev: DRM device
1927  *
1928  * This function can be used as the
1929  * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
1930  * need to call drm_fb_helper_hotplug_event().
1931  */
1932 void drm_fb_helper_output_poll_changed(struct drm_device *dev)
1933 {
1934         drm_fb_helper_hotplug_event(dev->fb_helper);
1935 }
1936 EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
1937
1938 /* @user: 1=userspace, 0=fbcon */
1939 static int drm_fbdev_fb_open(struct fb_info *info, int user)
1940 {
1941         struct drm_fb_helper *fb_helper = info->par;
1942
1943         /* No need to take a ref for fbcon because it unbinds on unregister */
1944         if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
1945                 return -ENODEV;
1946
1947         return 0;
1948 }
1949
1950 static int drm_fbdev_fb_release(struct fb_info *info, int user)
1951 {
1952         struct drm_fb_helper *fb_helper = info->par;
1953
1954         if (user)
1955                 module_put(fb_helper->dev->driver->fops->owner);
1956
1957         return 0;
1958 }
1959
1960 static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
1961 {
1962         struct fb_info *fbi = fb_helper->fbdev;
1963         void *shadow = NULL;
1964
1965         if (!fb_helper->dev)
1966                 return;
1967
1968         if (fbi && fbi->fbdefio) {
1969                 fb_deferred_io_cleanup(fbi);
1970                 shadow = fbi->screen_buffer;
1971         }
1972
1973         drm_fb_helper_fini(fb_helper);
1974
1975         vfree(shadow);
1976
1977         drm_client_framebuffer_delete(fb_helper->buffer);
1978 }
1979
1980 static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
1981 {
1982         drm_fbdev_cleanup(fb_helper);
1983         drm_client_release(&fb_helper->client);
1984         kfree(fb_helper);
1985 }
1986
1987 /*
1988  * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
1989  * unregister_framebuffer() or fb_release().
1990  */
1991 static void drm_fbdev_fb_destroy(struct fb_info *info)
1992 {
1993         drm_fbdev_release(info->par);
1994 }
1995
1996 static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
1997 {
1998         struct drm_fb_helper *fb_helper = info->par;
1999
2000         if (fb_helper->dev->driver->gem_prime_mmap)
2001                 return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
2002         else
2003                 return -ENODEV;
2004 }
2005
2006 static const struct fb_ops drm_fbdev_fb_ops = {
2007         .owner          = THIS_MODULE,
2008         DRM_FB_HELPER_DEFAULT_OPS,
2009         .fb_open        = drm_fbdev_fb_open,
2010         .fb_release     = drm_fbdev_fb_release,
2011         .fb_destroy     = drm_fbdev_fb_destroy,
2012         .fb_mmap        = drm_fbdev_fb_mmap,
2013         .fb_read        = drm_fb_helper_sys_read,
2014         .fb_write       = drm_fb_helper_sys_write,
2015         .fb_fillrect    = drm_fb_helper_sys_fillrect,
2016         .fb_copyarea    = drm_fb_helper_sys_copyarea,
2017         .fb_imageblit   = drm_fb_helper_sys_imageblit,
2018 };
2019
2020 static struct fb_deferred_io drm_fbdev_defio = {
2021         .delay          = HZ / 20,
2022         .deferred_io    = drm_fb_helper_deferred_io,
2023 };
2024
2025 /*
2026  * This function uses the client API to create a framebuffer backed by a dumb buffer.
2027  *
2028  * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
2029  * fb_copyarea, fb_imageblit.
2030  */
2031 static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
2032                                        struct drm_fb_helper_surface_size *sizes)
2033 {
2034         struct drm_client_dev *client = &fb_helper->client;
2035         struct drm_device *dev = fb_helper->dev;
2036         struct drm_client_buffer *buffer;
2037         struct drm_framebuffer *fb;
2038         struct fb_info *fbi;
2039         u32 format;
2040         void *vaddr;
2041
2042         drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
2043                     sizes->surface_width, sizes->surface_height,
2044                     sizes->surface_bpp);
2045
2046         format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
2047         buffer = drm_client_framebuffer_create(client, sizes->surface_width,
2048                                                sizes->surface_height, format);
2049         if (IS_ERR(buffer))
2050                 return PTR_ERR(buffer);
2051
2052         fb_helper->buffer = buffer;
2053         fb_helper->fb = buffer->fb;
2054         fb = buffer->fb;
2055
2056         fbi = drm_fb_helper_alloc_fbi(fb_helper);
2057         if (IS_ERR(fbi))
2058                 return PTR_ERR(fbi);
2059
2060         fbi->fbops = &drm_fbdev_fb_ops;
2061         fbi->screen_size = fb->height * fb->pitches[0];
2062         fbi->fix.smem_len = fbi->screen_size;
2063
2064         drm_fb_helper_fill_info(fbi, fb_helper, sizes);
2065
2066         if (drm_fbdev_use_shadow_fb(fb_helper)) {
2067                 fbi->screen_buffer = vzalloc(fbi->screen_size);
2068                 if (!fbi->screen_buffer)
2069                         return -ENOMEM;
2070
2071                 fbi->fbdefio = &drm_fbdev_defio;
2072
2073                 fb_deferred_io_init(fbi);
2074         } else {
2075                 /* buffer is mapped for HW framebuffer */
2076                 vaddr = drm_client_buffer_vmap(fb_helper->buffer);
2077                 if (IS_ERR(vaddr))
2078                         return PTR_ERR(vaddr);
2079
2080                 fbi->screen_buffer = vaddr;
2081                 /* Shamelessly leak the physical address to user-space */
2082 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2083                 if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
2084                         fbi->fix.smem_start =
2085                                 page_to_phys(virt_to_page(fbi->screen_buffer));
2086 #endif
2087         }
2088
2089         return 0;
2090 }
2091
2092 static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
2093         .fb_probe = drm_fb_helper_generic_probe,
2094 };
2095
2096 static void drm_fbdev_client_unregister(struct drm_client_dev *client)
2097 {
2098         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2099
2100         if (fb_helper->fbdev)
2101                 /* drm_fbdev_fb_destroy() takes care of cleanup */
2102                 drm_fb_helper_unregister_fbi(fb_helper);
2103         else
2104                 drm_fbdev_release(fb_helper);
2105 }
2106
2107 static int drm_fbdev_client_restore(struct drm_client_dev *client)
2108 {
2109         drm_fb_helper_lastclose(client->dev);
2110
2111         return 0;
2112 }
2113
2114 static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
2115 {
2116         struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2117         struct drm_device *dev = client->dev;
2118         int ret;
2119
2120         /* Setup is not retried if it has failed */
2121         if (!fb_helper->dev && fb_helper->funcs)
2122                 return 0;
2123
2124         if (dev->fb_helper)
2125                 return drm_fb_helper_hotplug_event(dev->fb_helper);
2126
2127         if (!dev->mode_config.num_connector) {
2128                 drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
2129                 return 0;
2130         }
2131
2132         drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
2133
2134         ret = drm_fb_helper_init(dev, fb_helper);
2135         if (ret)
2136                 goto err;
2137
2138         if (!drm_drv_uses_atomic_modeset(dev))
2139                 drm_helper_disable_unused_functions(dev);
2140
2141         ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
2142         if (ret)
2143                 goto err_cleanup;
2144
2145         return 0;
2146
2147 err_cleanup:
2148         drm_fbdev_cleanup(fb_helper);
2149 err:
2150         fb_helper->dev = NULL;
2151         fb_helper->fbdev = NULL;
2152
2153         drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
2154
2155         return ret;
2156 }
2157
2158 static const struct drm_client_funcs drm_fbdev_client_funcs = {
2159         .owner          = THIS_MODULE,
2160         .unregister     = drm_fbdev_client_unregister,
2161         .restore        = drm_fbdev_client_restore,
2162         .hotplug        = drm_fbdev_client_hotplug,
2163 };
2164
2165 /**
2166  * drm_fbdev_generic_setup() - Setup generic fbdev emulation
2167  * @dev: DRM device
2168  * @preferred_bpp: Preferred bits per pixel for the device.
2169  *                 @dev->mode_config.preferred_depth is used if this is zero.
2170  *
2171  * This function sets up generic fbdev emulation for drivers that supports
2172  * dumb buffers with a virtual address and that can be mmap'ed.
2173  * drm_fbdev_generic_setup() shall be called after the DRM driver registered
2174  * the new DRM device with drm_dev_register().
2175  *
2176  * Restore, hotplug events and teardown are all taken care of. Drivers that do
2177  * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
2178  * Simple drivers might use drm_mode_config_helper_suspend().
2179  *
2180  * Drivers that set the dirty callback on their framebuffer will get a shadow
2181  * fbdev buffer that is blitted onto the real buffer. This is done in order to
2182  * make deferred I/O work with all kinds of buffers. A shadow buffer can be
2183  * requested explicitly by setting struct drm_mode_config.prefer_shadow or
2184  * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is
2185  * required to use generic fbdev emulation with SHMEM helpers.
2186  *
2187  * This function is safe to call even when there are no connectors present.
2188  * Setup will be retried on the next hotplug event.
2189  *
2190  * The fbdev is destroyed by drm_dev_unregister().
2191  */
2192 void drm_fbdev_generic_setup(struct drm_device *dev,
2193                              unsigned int preferred_bpp)
2194 {
2195         struct drm_fb_helper *fb_helper;
2196         int ret;
2197
2198         drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
2199         drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
2200
2201         if (!drm_fbdev_emulation)
2202                 return;
2203
2204         fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
2205         if (!fb_helper) {
2206                 drm_err(dev, "Failed to allocate fb_helper\n");
2207                 return;
2208         }
2209
2210         ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
2211         if (ret) {
2212                 kfree(fb_helper);
2213                 drm_err(dev, "Failed to register client: %d\n", ret);
2214                 return;
2215         }
2216
2217         if (!preferred_bpp)
2218                 preferred_bpp = dev->mode_config.preferred_depth;
2219         if (!preferred_bpp)
2220                 preferred_bpp = 32;
2221         fb_helper->preferred_bpp = preferred_bpp;
2222
2223         ret = drm_fbdev_client_hotplug(&fb_helper->client);
2224         if (ret)
2225                 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
2226
2227         drm_client_register(&fb_helper->client);
2228 }
2229 EXPORT_SYMBOL(drm_fbdev_generic_setup);
2230
2231 /* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
2232  * but the module doesn't depend on any fb console symbols.  At least
2233  * attempt to load fbcon to avoid leaving the system without a usable console.
2234  */
2235 int __init drm_fb_helper_modinit(void)
2236 {
2237 #if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
2238         const char name[] = "fbcon";
2239         struct module *fbcon;
2240
2241         mutex_lock(&module_mutex);
2242         fbcon = find_module(name);
2243         mutex_unlock(&module_mutex);
2244
2245         if (!fbcon)
2246                 request_module_nowait(name);
2247 #endif
2248         return 0;
2249 }
2250 EXPORT_SYMBOL(drm_fb_helper_modinit);