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