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