drivers/gpu/drm/drm_fb_helper.c

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