linux/drivers/gpu/drm/drm_fb_helper.c
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   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
  52static bool drm_fbdev_emulation = true;
  53module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
  54MODULE_PARM_DESC(fbdev_emulation,
  55                 "Enable legacy fbdev emulation [default=true]");
  56
  57static int drm_fbdev_overalloc = CONFIG_DRM_FBDEV_OVERALLOC;
  58module_param(drm_fbdev_overalloc, int, 0444);
  59MODULE_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)
  76static bool drm_leak_fbdev_smem = false;
  77module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
  78MODULE_PARM_DESC(drm_leak_fbdev_smem,
  79                 "Allow unsafe leaking fbdev physical smem address [default=false]");
  80#endif
  81
  82static LIST_HEAD(kernel_fb_helper_list);
  83static 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
 135static 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 */
 154int 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}
 184EXPORT_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 */
 190int 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}
 228EXPORT_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 */
 241int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 242{
 243        bool do_delayed;
 244        int ret;
 245
 246        if (!drm_fbdev_emulation || !fb_helper)
 247                return -ENODEV;
 248
 249        if (READ_ONCE(fb_helper->deferred_setup))
 250                return 0;
 251
 252        mutex_lock(&fb_helper->lock);
 253        /*
 254         * TODO:
 255         * We should bail out here if there is a master by dropping _force.
 256         * Currently these igt tests fail if we do that:
 257         * - kms_fbcon_fbt@psr
 258         * - kms_fbcon_fbt@psr-suspend
 259         *
 260         * So first these tests need to be fixed so they drop master or don't
 261         * have an fd open.
 262         */
 263        ret = drm_client_modeset_commit_force(&fb_helper->client);
 264
 265        do_delayed = fb_helper->delayed_hotplug;
 266        if (do_delayed)
 267                fb_helper->delayed_hotplug = false;
 268        mutex_unlock(&fb_helper->lock);
 269
 270        if (do_delayed)
 271                drm_fb_helper_hotplug_event(fb_helper);
 272
 273        return ret;
 274}
 275EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 276
 277#ifdef CONFIG_MAGIC_SYSRQ
 278/*
 279 * restore fbcon display for all kms driver's using this helper, used for sysrq
 280 * and panic handling.
 281 */
 282static bool drm_fb_helper_force_kernel_mode(void)
 283{
 284        bool ret, error = false;
 285        struct drm_fb_helper *helper;
 286
 287        if (list_empty(&kernel_fb_helper_list))
 288                return false;
 289
 290        list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 291                struct drm_device *dev = helper->dev;
 292
 293                if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 294                        continue;
 295
 296                mutex_lock(&helper->lock);
 297                ret = drm_client_modeset_commit_force(&helper->client);
 298                if (ret)
 299                        error = true;
 300                mutex_unlock(&helper->lock);
 301        }
 302        return error;
 303}
 304
 305static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 306{
 307        bool ret;
 308
 309        ret = drm_fb_helper_force_kernel_mode();
 310        if (ret == true)
 311                DRM_ERROR("Failed to restore crtc configuration\n");
 312}
 313static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
 314
 315static void drm_fb_helper_sysrq(int dummy1)
 316{
 317        schedule_work(&drm_fb_helper_restore_work);
 318}
 319
 320static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 321        .handler = drm_fb_helper_sysrq,
 322        .help_msg = "force-fb(V)",
 323        .action_msg = "Restore framebuffer console",
 324};
 325#else
 326static struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
 327#endif
 328
 329static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 330{
 331        struct drm_fb_helper *fb_helper = info->par;
 332
 333        mutex_lock(&fb_helper->lock);
 334        drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
 335        mutex_unlock(&fb_helper->lock);
 336}
 337
 338/**
 339 * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
 340 * @blank: desired blanking state
 341 * @info: fbdev registered by the helper
 342 */
 343int drm_fb_helper_blank(int blank, struct fb_info *info)
 344{
 345        if (oops_in_progress)
 346                return -EBUSY;
 347
 348        switch (blank) {
 349        /* Display: On; HSync: On, VSync: On */
 350        case FB_BLANK_UNBLANK:
 351                drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
 352                break;
 353        /* Display: Off; HSync: On, VSync: On */
 354        case FB_BLANK_NORMAL:
 355                drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 356                break;
 357        /* Display: Off; HSync: Off, VSync: On */
 358        case FB_BLANK_HSYNC_SUSPEND:
 359                drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 360                break;
 361        /* Display: Off; HSync: On, VSync: Off */
 362        case FB_BLANK_VSYNC_SUSPEND:
 363                drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
 364                break;
 365        /* Display: Off; HSync: Off, VSync: Off */
 366        case FB_BLANK_POWERDOWN:
 367                drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
 368                break;
 369        }
 370        return 0;
 371}
 372EXPORT_SYMBOL(drm_fb_helper_blank);
 373
 374static void drm_fb_helper_resume_worker(struct work_struct *work)
 375{
 376        struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 377                                                    resume_work);
 378
 379        console_lock();
 380        fb_set_suspend(helper->fbdev, 0);
 381        console_unlock();
 382}
 383
 384static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
 385                                          struct drm_clip_rect *clip)
 386{
 387        struct drm_framebuffer *fb = fb_helper->fb;
 388        unsigned int cpp = fb->format->cpp[0];
 389        size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
 390        void *src = fb_helper->fbdev->screen_buffer + offset;
 391        void *dst = fb_helper->buffer->vaddr + offset;
 392        size_t len = (clip->x2 - clip->x1) * cpp;
 393        unsigned int y;
 394
 395        for (y = clip->y1; y < clip->y2; y++) {
 396                memcpy(dst, src, len);
 397                src += fb->pitches[0];
 398                dst += fb->pitches[0];
 399        }
 400}
 401
 402static void drm_fb_helper_dirty_work(struct work_struct *work)
 403{
 404        struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 405                                                    dirty_work);
 406        struct drm_clip_rect *clip = &helper->dirty_clip;
 407        struct drm_clip_rect clip_copy;
 408        unsigned long flags;
 409        void *vaddr;
 410
 411        spin_lock_irqsave(&helper->dirty_lock, flags);
 412        clip_copy = *clip;
 413        clip->x1 = clip->y1 = ~0;
 414        clip->x2 = clip->y2 = 0;
 415        spin_unlock_irqrestore(&helper->dirty_lock, flags);
 416
 417        /* call dirty callback only when it has been really touched */
 418        if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
 419
 420                /* Generic fbdev uses a shadow buffer */
 421                if (helper->buffer) {
 422                        vaddr = drm_client_buffer_vmap(helper->buffer);
 423                        if (IS_ERR(vaddr))
 424                                return;
 425                        drm_fb_helper_dirty_blit_real(helper, &clip_copy);
 426                }
 427                if (helper->fb->funcs->dirty)
 428                        helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
 429                                                 &clip_copy, 1);
 430
 431                if (helper->buffer)
 432                        drm_client_buffer_vunmap(helper->buffer);
 433        }
 434}
 435
 436/**
 437 * drm_fb_helper_prepare - setup a drm_fb_helper structure
 438 * @dev: DRM device
 439 * @helper: driver-allocated fbdev helper structure to set up
 440 * @funcs: pointer to structure of functions associate with this helper
 441 *
 442 * Sets up the bare minimum to make the framebuffer helper usable. This is
 443 * useful to implement race-free initialization of the polling helpers.
 444 */
 445void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 446                           const struct drm_fb_helper_funcs *funcs)
 447{
 448        INIT_LIST_HEAD(&helper->kernel_fb_list);
 449        spin_lock_init(&helper->dirty_lock);
 450        INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 451        INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
 452        helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
 453        mutex_init(&helper->lock);
 454        helper->funcs = funcs;
 455        helper->dev = dev;
 456}
 457EXPORT_SYMBOL(drm_fb_helper_prepare);
 458
 459/**
 460 * drm_fb_helper_init - initialize a &struct drm_fb_helper
 461 * @dev: drm device
 462 * @fb_helper: driver-allocated fbdev helper structure to initialize
 463 * @max_conn_count: max connector count (not used)
 464 *
 465 * This allocates the structures for the fbdev helper with the given limits.
 466 * Note that this won't yet touch the hardware (through the driver interfaces)
 467 * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 468 * to allow driver writes more control over the exact init sequence.
 469 *
 470 * Drivers must call drm_fb_helper_prepare() before calling this function.
 471 *
 472 * RETURNS:
 473 * Zero if everything went ok, nonzero otherwise.
 474 */
 475int drm_fb_helper_init(struct drm_device *dev,
 476                       struct drm_fb_helper *fb_helper,
 477                       int max_conn_count)
 478{
 479        int ret;
 480
 481        if (!drm_fbdev_emulation) {
 482                dev->fb_helper = fb_helper;
 483                return 0;
 484        }
 485
 486        /*
 487         * If this is not the generic fbdev client, initialize a drm_client
 488         * without callbacks so we can use the modesets.
 489         */
 490        if (!fb_helper->client.funcs) {
 491                ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
 492                if (ret)
 493                        return ret;
 494        }
 495
 496        dev->fb_helper = fb_helper;
 497
 498        return 0;
 499}
 500EXPORT_SYMBOL(drm_fb_helper_init);
 501
 502/**
 503 * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
 504 * @fb_helper: driver-allocated fbdev helper
 505 *
 506 * A helper to alloc fb_info and the members cmap and apertures. Called
 507 * by the driver within the fb_probe fb_helper callback function. Drivers do not
 508 * need to release the allocated fb_info structure themselves, this is
 509 * automatically done when calling drm_fb_helper_fini().
 510 *
 511 * RETURNS:
 512 * fb_info pointer if things went okay, pointer containing error code
 513 * otherwise
 514 */
 515struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
 516{
 517        struct device *dev = fb_helper->dev->dev;
 518        struct fb_info *info;
 519        int ret;
 520
 521        info = framebuffer_alloc(0, dev);
 522        if (!info)
 523                return ERR_PTR(-ENOMEM);
 524
 525        ret = fb_alloc_cmap(&info->cmap, 256, 0);
 526        if (ret)
 527                goto err_release;
 528
 529        info->apertures = alloc_apertures(1);
 530        if (!info->apertures) {
 531                ret = -ENOMEM;
 532                goto err_free_cmap;
 533        }
 534
 535        fb_helper->fbdev = info;
 536        info->skip_vt_switch = true;
 537
 538        return info;
 539
 540err_free_cmap:
 541        fb_dealloc_cmap(&info->cmap);
 542err_release:
 543        framebuffer_release(info);
 544        return ERR_PTR(ret);
 545}
 546EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
 547
 548/**
 549 * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
 550 * @fb_helper: driver-allocated fbdev helper, can be NULL
 551 *
 552 * A wrapper around unregister_framebuffer, to release the fb_info
 553 * framebuffer device. This must be called before releasing all resources for
 554 * @fb_helper by calling drm_fb_helper_fini().
 555 */
 556void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
 557{
 558        if (fb_helper && fb_helper->fbdev)
 559                unregister_framebuffer(fb_helper->fbdev);
 560}
 561EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
 562
 563/**
 564 * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 565 * @fb_helper: driver-allocated fbdev helper, can be NULL
 566 *
 567 * This cleans up all remaining resources associated with @fb_helper.
 568 */
 569void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 570{
 571        struct fb_info *info;
 572
 573        if (!fb_helper)
 574                return;
 575
 576        fb_helper->dev->fb_helper = NULL;
 577
 578        if (!drm_fbdev_emulation)
 579                return;
 580
 581        cancel_work_sync(&fb_helper->resume_work);
 582        cancel_work_sync(&fb_helper->dirty_work);
 583
 584        info = fb_helper->fbdev;
 585        if (info) {
 586                if (info->cmap.len)
 587                        fb_dealloc_cmap(&info->cmap);
 588                framebuffer_release(info);
 589        }
 590        fb_helper->fbdev = NULL;
 591
 592        mutex_lock(&kernel_fb_helper_lock);
 593        if (!list_empty(&fb_helper->kernel_fb_list)) {
 594                list_del(&fb_helper->kernel_fb_list);
 595                if (list_empty(&kernel_fb_helper_list))
 596                        unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 597        }
 598        mutex_unlock(&kernel_fb_helper_lock);
 599
 600        mutex_destroy(&fb_helper->lock);
 601
 602        if (!fb_helper->client.funcs)
 603                drm_client_release(&fb_helper->client);
 604}
 605EXPORT_SYMBOL(drm_fb_helper_fini);
 606
 607static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
 608{
 609        struct drm_device *dev = fb_helper->dev;
 610        struct drm_framebuffer *fb = fb_helper->fb;
 611
 612        return dev->mode_config.prefer_shadow_fbdev ||
 613               dev->mode_config.prefer_shadow ||
 614               fb->funcs->dirty;
 615}
 616
 617static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
 618                                u32 width, u32 height)
 619{
 620        struct drm_fb_helper *helper = info->par;
 621        struct drm_clip_rect *clip = &helper->dirty_clip;
 622        unsigned long flags;
 623
 624        if (!drm_fbdev_use_shadow_fb(helper))
 625                return;
 626
 627        spin_lock_irqsave(&helper->dirty_lock, flags);
 628        clip->x1 = min_t(u32, clip->x1, x);
 629        clip->y1 = min_t(u32, clip->y1, y);
 630        clip->x2 = max_t(u32, clip->x2, x + width);
 631        clip->y2 = max_t(u32, clip->y2, y + height);
 632        spin_unlock_irqrestore(&helper->dirty_lock, flags);
 633
 634        schedule_work(&helper->dirty_work);
 635}
 636
 637/**
 638 * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 639 * @info: fb_info struct pointer
 640 * @pagelist: list of dirty mmap framebuffer pages
 641 *
 642 * This function is used as the &fb_deferred_io.deferred_io
 643 * callback function for flushing the fbdev mmap writes.
 644 */
 645void drm_fb_helper_deferred_io(struct fb_info *info,
 646                               struct list_head *pagelist)
 647{
 648        unsigned long start, end, min, max;
 649        struct page *page;
 650        u32 y1, y2;
 651
 652        min = ULONG_MAX;
 653        max = 0;
 654        list_for_each_entry(page, pagelist, lru) {
 655                start = page->index << PAGE_SHIFT;
 656                end = start + PAGE_SIZE - 1;
 657                min = min(min, start);
 658                max = max(max, end);
 659        }
 660
 661        if (min < max) {
 662                y1 = min / info->fix.line_length;
 663                y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 664                           info->var.yres);
 665                drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
 666        }
 667}
 668EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 669
 670/**
 671 * drm_fb_helper_sys_read - wrapper around fb_sys_read
 672 * @info: fb_info struct pointer
 673 * @buf: userspace buffer to read from framebuffer memory
 674 * @count: number of bytes to read from framebuffer memory
 675 * @ppos: read offset within framebuffer memory
 676 *
 677 * A wrapper around fb_sys_read implemented by fbdev core
 678 */
 679ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 680                               size_t count, loff_t *ppos)
 681{
 682        return fb_sys_read(info, buf, count, ppos);
 683}
 684EXPORT_SYMBOL(drm_fb_helper_sys_read);
 685
 686/**
 687 * drm_fb_helper_sys_write - wrapper around fb_sys_write
 688 * @info: fb_info struct pointer
 689 * @buf: userspace buffer to write to framebuffer memory
 690 * @count: number of bytes to write to framebuffer memory
 691 * @ppos: write offset within framebuffer memory
 692 *
 693 * A wrapper around fb_sys_write implemented by fbdev core
 694 */
 695ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 696                                size_t count, loff_t *ppos)
 697{
 698        ssize_t ret;
 699
 700        ret = fb_sys_write(info, buf, count, ppos);
 701        if (ret > 0)
 702                drm_fb_helper_dirty(info, 0, 0, info->var.xres,
 703                                    info->var.yres);
 704
 705        return ret;
 706}
 707EXPORT_SYMBOL(drm_fb_helper_sys_write);
 708
 709/**
 710 * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
 711 * @info: fbdev registered by the helper
 712 * @rect: info about rectangle to fill
 713 *
 714 * A wrapper around sys_fillrect implemented by fbdev core
 715 */
 716void drm_fb_helper_sys_fillrect(struct fb_info *info,
 717                                const struct fb_fillrect *rect)
 718{
 719        sys_fillrect(info, rect);
 720        drm_fb_helper_dirty(info, rect->dx, rect->dy,
 721                            rect->width, rect->height);
 722}
 723EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 724
 725/**
 726 * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
 727 * @info: fbdev registered by the helper
 728 * @area: info about area to copy
 729 *
 730 * A wrapper around sys_copyarea implemented by fbdev core
 731 */
 732void drm_fb_helper_sys_copyarea(struct fb_info *info,
 733                                const struct fb_copyarea *area)
 734{
 735        sys_copyarea(info, area);
 736        drm_fb_helper_dirty(info, area->dx, area->dy,
 737                            area->width, area->height);
 738}
 739EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 740
 741/**
 742 * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
 743 * @info: fbdev registered by the helper
 744 * @image: info about image to blit
 745 *
 746 * A wrapper around sys_imageblit implemented by fbdev core
 747 */
 748void drm_fb_helper_sys_imageblit(struct fb_info *info,
 749                                 const struct fb_image *image)
 750{
 751        sys_imageblit(info, image);
 752        drm_fb_helper_dirty(info, image->dx, image->dy,
 753                            image->width, image->height);
 754}
 755EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 756
 757/**
 758 * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
 759 * @info: fbdev registered by the helper
 760 * @rect: info about rectangle to fill
 761 *
 762 * A wrapper around cfb_fillrect implemented by fbdev core
 763 */
 764void drm_fb_helper_cfb_fillrect(struct fb_info *info,
 765                                const struct fb_fillrect *rect)
 766{
 767        cfb_fillrect(info, rect);
 768        drm_fb_helper_dirty(info, rect->dx, rect->dy,
 769                            rect->width, rect->height);
 770}
 771EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
 772
 773/**
 774 * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
 775 * @info: fbdev registered by the helper
 776 * @area: info about area to copy
 777 *
 778 * A wrapper around cfb_copyarea implemented by fbdev core
 779 */
 780void drm_fb_helper_cfb_copyarea(struct fb_info *info,
 781                                const struct fb_copyarea *area)
 782{
 783        cfb_copyarea(info, area);
 784        drm_fb_helper_dirty(info, area->dx, area->dy,
 785                            area->width, area->height);
 786}
 787EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
 788
 789/**
 790 * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
 791 * @info: fbdev registered by the helper
 792 * @image: info about image to blit
 793 *
 794 * A wrapper around cfb_imageblit implemented by fbdev core
 795 */
 796void drm_fb_helper_cfb_imageblit(struct fb_info *info,
 797                                 const struct fb_image *image)
 798{
 799        cfb_imageblit(info, image);
 800        drm_fb_helper_dirty(info, image->dx, image->dy,
 801                            image->width, image->height);
 802}
 803EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
 804
 805/**
 806 * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
 807 * @fb_helper: driver-allocated fbdev helper, can be NULL
 808 * @suspend: whether to suspend or resume
 809 *
 810 * A wrapper around fb_set_suspend implemented by fbdev core.
 811 * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
 812 * the lock yourself
 813 */
 814void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
 815{
 816        if (fb_helper && fb_helper->fbdev)
 817                fb_set_suspend(fb_helper->fbdev, suspend);
 818}
 819EXPORT_SYMBOL(drm_fb_helper_set_suspend);
 820
 821/**
 822 * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
 823 *                                      takes the console lock
 824 * @fb_helper: driver-allocated fbdev helper, can be NULL
 825 * @suspend: whether to suspend or resume
 826 *
 827 * A wrapper around fb_set_suspend() that takes the console lock. If the lock
 828 * isn't available on resume, a worker is tasked with waiting for the lock
 829 * to become available. The console lock can be pretty contented on resume
 830 * due to all the printk activity.
 831 *
 832 * This function can be called multiple times with the same state since
 833 * &fb_info.state is checked to see if fbdev is running or not before locking.
 834 *
 835 * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
 836 */
 837void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
 838                                        bool suspend)
 839{
 840        if (!fb_helper || !fb_helper->fbdev)
 841                return;
 842
 843        /* make sure there's no pending/ongoing resume */
 844        flush_work(&fb_helper->resume_work);
 845
 846        if (suspend) {
 847                if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
 848                        return;
 849
 850                console_lock();
 851
 852        } else {
 853                if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
 854                        return;
 855
 856                if (!console_trylock()) {
 857                        schedule_work(&fb_helper->resume_work);
 858                        return;
 859                }
 860        }
 861
 862        fb_set_suspend(fb_helper->fbdev, suspend);
 863        console_unlock();
 864}
 865EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
 866
 867static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 868{
 869        u32 *palette = (u32 *)info->pseudo_palette;
 870        int i;
 871
 872        if (cmap->start + cmap->len > 16)
 873                return -EINVAL;
 874
 875        for (i = 0; i < cmap->len; ++i) {
 876                u16 red = cmap->red[i];
 877                u16 green = cmap->green[i];
 878                u16 blue = cmap->blue[i];
 879                u32 value;
 880
 881                red >>= 16 - info->var.red.length;
 882                green >>= 16 - info->var.green.length;
 883                blue >>= 16 - info->var.blue.length;
 884                value = (red << info->var.red.offset) |
 885                        (green << info->var.green.offset) |
 886                        (blue << info->var.blue.offset);
 887                if (info->var.transp.length > 0) {
 888                        u32 mask = (1 << info->var.transp.length) - 1;
 889
 890                        mask <<= info->var.transp.offset;
 891                        value |= mask;
 892                }
 893                palette[cmap->start + i] = value;
 894        }
 895
 896        return 0;
 897}
 898
 899static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
 900{
 901        struct drm_fb_helper *fb_helper = info->par;
 902        struct drm_mode_set *modeset;
 903        struct drm_crtc *crtc;
 904        u16 *r, *g, *b;
 905        int ret = 0;
 906
 907        drm_modeset_lock_all(fb_helper->dev);
 908        drm_client_for_each_modeset(modeset, &fb_helper->client) {
 909                crtc = modeset->crtc;
 910                if (!crtc->funcs->gamma_set || !crtc->gamma_size)
 911                        return -EINVAL;
 912
 913                if (cmap->start + cmap->len > crtc->gamma_size)
 914                        return -EINVAL;
 915
 916                r = crtc->gamma_store;
 917                g = r + crtc->gamma_size;
 918                b = g + crtc->gamma_size;
 919
 920                memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
 921                memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
 922                memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
 923
 924                ret = crtc->funcs->gamma_set(crtc, r, g, b,
 925                                             crtc->gamma_size, NULL);
 926                if (ret)
 927                        return ret;
 928        }
 929        drm_modeset_unlock_all(fb_helper->dev);
 930
 931        return ret;
 932}
 933
 934static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
 935                                                       struct fb_cmap *cmap)
 936{
 937        struct drm_device *dev = crtc->dev;
 938        struct drm_property_blob *gamma_lut;
 939        struct drm_color_lut *lut;
 940        int size = crtc->gamma_size;
 941        int i;
 942
 943        if (!size || cmap->start + cmap->len > size)
 944                return ERR_PTR(-EINVAL);
 945
 946        gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
 947        if (IS_ERR(gamma_lut))
 948                return gamma_lut;
 949
 950        lut = gamma_lut->data;
 951        if (cmap->start || cmap->len != size) {
 952                u16 *r = crtc->gamma_store;
 953                u16 *g = r + crtc->gamma_size;
 954                u16 *b = g + crtc->gamma_size;
 955
 956                for (i = 0; i < cmap->start; i++) {
 957                        lut[i].red = r[i];
 958                        lut[i].green = g[i];
 959                        lut[i].blue = b[i];
 960                }
 961                for (i = cmap->start + cmap->len; i < size; i++) {
 962                        lut[i].red = r[i];
 963                        lut[i].green = g[i];
 964                        lut[i].blue = b[i];
 965                }
 966        }
 967
 968        for (i = 0; i < cmap->len; i++) {
 969                lut[cmap->start + i].red = cmap->red[i];
 970                lut[cmap->start + i].green = cmap->green[i];
 971                lut[cmap->start + i].blue = cmap->blue[i];
 972        }
 973
 974        return gamma_lut;
 975}
 976
 977static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
 978{
 979        struct drm_fb_helper *fb_helper = info->par;
 980        struct drm_device *dev = fb_helper->dev;
 981        struct drm_property_blob *gamma_lut = NULL;
 982        struct drm_modeset_acquire_ctx ctx;
 983        struct drm_crtc_state *crtc_state;
 984        struct drm_atomic_state *state;
 985        struct drm_mode_set *modeset;
 986        struct drm_crtc *crtc;
 987        u16 *r, *g, *b;
 988        bool replaced;
 989        int ret = 0;
 990
 991        drm_modeset_acquire_init(&ctx, 0);
 992
 993        state = drm_atomic_state_alloc(dev);
 994        if (!state) {
 995                ret = -ENOMEM;
 996                goto out_ctx;
 997        }
 998
 999        state->acquire_ctx = &ctx;
1000retry:
1001        drm_client_for_each_modeset(modeset, &fb_helper->client) {
1002                crtc = modeset->crtc;
1003
1004                if (!gamma_lut)
1005                        gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1006                if (IS_ERR(gamma_lut)) {
1007                        ret = PTR_ERR(gamma_lut);
1008                        gamma_lut = NULL;
1009                        goto out_state;
1010                }
1011
1012                crtc_state = drm_atomic_get_crtc_state(state, crtc);
1013                if (IS_ERR(crtc_state)) {
1014                        ret = PTR_ERR(crtc_state);
1015                        goto out_state;
1016                }
1017
1018                replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1019                                                      NULL);
1020                replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1021                replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1022                                                      gamma_lut);
1023                crtc_state->color_mgmt_changed |= replaced;
1024        }
1025
1026        ret = drm_atomic_commit(state);
1027        if (ret)
1028                goto out_state;
1029
1030        drm_client_for_each_modeset(modeset, &fb_helper->client) {
1031                crtc = modeset->crtc;
1032
1033                r = crtc->gamma_store;
1034                g = r + crtc->gamma_size;
1035                b = g + crtc->gamma_size;
1036
1037                memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1038                memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1039                memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1040        }
1041
1042out_state:
1043        if (ret == -EDEADLK)
1044                goto backoff;
1045
1046        drm_property_blob_put(gamma_lut);
1047        drm_atomic_state_put(state);
1048out_ctx:
1049        drm_modeset_drop_locks(&ctx);
1050        drm_modeset_acquire_fini(&ctx);
1051
1052        return ret;
1053
1054backoff:
1055        drm_atomic_state_clear(state);
1056        drm_modeset_backoff(&ctx);
1057        goto retry;
1058}
1059
1060/**
1061 * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1062 * @cmap: cmap to set
1063 * @info: fbdev registered by the helper
1064 */
1065int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1066{
1067        struct drm_fb_helper *fb_helper = info->par;
1068        struct drm_device *dev = fb_helper->dev;
1069        int ret;
1070
1071        if (oops_in_progress)
1072                return -EBUSY;
1073
1074        mutex_lock(&fb_helper->lock);
1075
1076        if (!drm_master_internal_acquire(dev)) {
1077                ret = -EBUSY;
1078                goto unlock;
1079        }
1080
1081        mutex_lock(&fb_helper->client.modeset_mutex);
1082        if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1083                ret = setcmap_pseudo_palette(cmap, info);
1084        else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1085                ret = setcmap_atomic(cmap, info);
1086        else
1087                ret = setcmap_legacy(cmap, info);
1088        mutex_unlock(&fb_helper->client.modeset_mutex);
1089
1090        drm_master_internal_release(dev);
1091unlock:
1092        mutex_unlock(&fb_helper->lock);
1093
1094        return ret;
1095}
1096EXPORT_SYMBOL(drm_fb_helper_setcmap);
1097
1098/**
1099 * drm_fb_helper_ioctl - legacy ioctl implementation
1100 * @info: fbdev registered by the helper
1101 * @cmd: ioctl command
1102 * @arg: ioctl argument
1103 *
1104 * A helper to implement the standard fbdev ioctl. Only
1105 * FBIO_WAITFORVSYNC is implemented for now.
1106 */
1107int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1108                        unsigned long arg)
1109{
1110        struct drm_fb_helper *fb_helper = info->par;
1111        struct drm_device *dev = fb_helper->dev;
1112        struct drm_crtc *crtc;
1113        int ret = 0;
1114
1115        mutex_lock(&fb_helper->lock);
1116        if (!drm_master_internal_acquire(dev)) {
1117                ret = -EBUSY;
1118                goto unlock;
1119        }
1120
1121        switch (cmd) {
1122        case FBIO_WAITFORVSYNC:
1123                /*
1124                 * Only consider the first CRTC.
1125                 *
1126                 * This ioctl is supposed to take the CRTC number as
1127                 * an argument, but in fbdev times, what that number
1128                 * was supposed to be was quite unclear, different
1129                 * drivers were passing that argument differently
1130                 * (some by reference, some by value), and most of the
1131                 * userspace applications were just hardcoding 0 as an
1132                 * argument.
1133                 *
1134                 * The first CRTC should be the integrated panel on
1135                 * most drivers, so this is the best choice we can
1136                 * make. If we're not smart enough here, one should
1137                 * just consider switch the userspace to KMS.
1138                 */
1139                crtc = fb_helper->client.modesets[0].crtc;
1140
1141                /*
1142                 * Only wait for a vblank event if the CRTC is
1143                 * enabled, otherwise just don't do anythintg,
1144                 * not even report an error.
1145                 */
1146                ret = drm_crtc_vblank_get(crtc);
1147                if (!ret) {
1148                        drm_crtc_wait_one_vblank(crtc);
1149                        drm_crtc_vblank_put(crtc);
1150                }
1151
1152                ret = 0;
1153                break;
1154        default:
1155                ret = -ENOTTY;
1156        }
1157
1158        drm_master_internal_release(dev);
1159unlock:
1160        mutex_unlock(&fb_helper->lock);
1161        return ret;
1162}
1163EXPORT_SYMBOL(drm_fb_helper_ioctl);
1164
1165static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1166                                      const struct fb_var_screeninfo *var_2)
1167{
1168        return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1169               var_1->grayscale == var_2->grayscale &&
1170               var_1->red.offset == var_2->red.offset &&
1171               var_1->red.length == var_2->red.length &&
1172               var_1->red.msb_right == var_2->red.msb_right &&
1173               var_1->green.offset == var_2->green.offset &&
1174               var_1->green.length == var_2->green.length &&
1175               var_1->green.msb_right == var_2->green.msb_right &&
1176               var_1->blue.offset == var_2->blue.offset &&
1177               var_1->blue.length == var_2->blue.length &&
1178               var_1->blue.msb_right == var_2->blue.msb_right &&
1179               var_1->transp.offset == var_2->transp.offset &&
1180               var_1->transp.length == var_2->transp.length &&
1181               var_1->transp.msb_right == var_2->transp.msb_right;
1182}
1183
1184static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1185                                         u8 depth)
1186{
1187        switch (depth) {
1188        case 8:
1189                var->red.offset = 0;
1190                var->green.offset = 0;
1191                var->blue.offset = 0;
1192                var->red.length = 8; /* 8bit DAC */
1193                var->green.length = 8;
1194                var->blue.length = 8;
1195                var->transp.offset = 0;
1196                var->transp.length = 0;
1197                break;
1198        case 15:
1199                var->red.offset = 10;
1200                var->green.offset = 5;
1201                var->blue.offset = 0;
1202                var->red.length = 5;
1203                var->green.length = 5;
1204                var->blue.length = 5;
1205                var->transp.offset = 15;
1206                var->transp.length = 1;
1207                break;
1208        case 16:
1209                var->red.offset = 11;
1210                var->green.offset = 5;
1211                var->blue.offset = 0;
1212                var->red.length = 5;
1213                var->green.length = 6;
1214                var->blue.length = 5;
1215                var->transp.offset = 0;
1216                break;
1217        case 24:
1218                var->red.offset = 16;
1219                var->green.offset = 8;
1220                var->blue.offset = 0;
1221                var->red.length = 8;
1222                var->green.length = 8;
1223                var->blue.length = 8;
1224                var->transp.offset = 0;
1225                var->transp.length = 0;
1226                break;
1227        case 32:
1228                var->red.offset = 16;
1229                var->green.offset = 8;
1230                var->blue.offset = 0;
1231                var->red.length = 8;
1232                var->green.length = 8;
1233                var->blue.length = 8;
1234                var->transp.offset = 24;
1235                var->transp.length = 8;
1236                break;
1237        default:
1238                break;
1239        }
1240}
1241
1242/**
1243 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1244 * @var: screeninfo to check
1245 * @info: fbdev registered by the helper
1246 */
1247int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1248                            struct fb_info *info)
1249{
1250        struct drm_fb_helper *fb_helper = info->par;
1251        struct drm_framebuffer *fb = fb_helper->fb;
1252        struct drm_device *dev = fb_helper->dev;
1253
1254        if (in_dbg_master())
1255                return -EINVAL;
1256
1257        if (var->pixclock != 0) {
1258                drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1259                var->pixclock = 0;
1260        }
1261
1262        if ((drm_format_info_block_width(fb->format, 0) > 1) ||
1263            (drm_format_info_block_height(fb->format, 0) > 1))
1264                return -EINVAL;
1265
1266        /*
1267         * Changes struct fb_var_screeninfo are currently not pushed back
1268         * to KMS, hence fail if different settings are requested.
1269         */
1270        if (var->bits_per_pixel > fb->format->cpp[0] * 8 ||
1271            var->xres > fb->width || var->yres > fb->height ||
1272            var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1273                drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1274                          "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1275                          var->xres, var->yres, var->bits_per_pixel,
1276                          var->xres_virtual, var->yres_virtual,
1277                          fb->width, fb->height, fb->format->cpp[0] * 8);
1278                return -EINVAL;
1279        }
1280
1281        /*
1282         * Workaround for SDL 1.2, which is known to be setting all pixel format
1283         * fields values to zero in some cases. We treat this situation as a
1284         * kind of "use some reasonable autodetected values".
1285         */
1286        if (!var->red.offset     && !var->green.offset    &&
1287            !var->blue.offset    && !var->transp.offset   &&
1288            !var->red.length     && !var->green.length    &&
1289            !var->blue.length    && !var->transp.length   &&
1290            !var->red.msb_right  && !var->green.msb_right &&
1291            !var->blue.msb_right && !var->transp.msb_right) {
1292                drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
1293        }
1294
1295        /*
1296         * Likewise, bits_per_pixel should be rounded up to a supported value.
1297         */
1298        var->bits_per_pixel = fb->format->cpp[0] * 8;
1299
1300        /*
1301         * drm fbdev emulation doesn't support changing the pixel format at all,
1302         * so reject all pixel format changing requests.
1303         */
1304        if (!drm_fb_pixel_format_equal(var, &info->var)) {
1305                drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1306                return -EINVAL;
1307        }
1308
1309        return 0;
1310}
1311EXPORT_SYMBOL(drm_fb_helper_check_var);
1312
1313/**
1314 * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1315 * @info: fbdev registered by the helper
1316 *
1317 * This will let fbcon do the mode init and is called at initialization time by
1318 * the fbdev core when registering the driver, and later on through the hotplug
1319 * callback.
1320 */
1321int drm_fb_helper_set_par(struct fb_info *info)
1322{
1323        struct drm_fb_helper *fb_helper = info->par;
1324        struct fb_var_screeninfo *var = &info->var;
1325
1326        if (oops_in_progress)
1327                return -EBUSY;
1328
1329        if (var->pixclock != 0) {
1330                drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1331                return -EINVAL;
1332        }
1333
1334        drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper);
1335
1336        return 0;
1337}
1338EXPORT_SYMBOL(drm_fb_helper_set_par);
1339
1340static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1341{
1342        struct drm_mode_set *mode_set;
1343
1344        mutex_lock(&fb_helper->client.modeset_mutex);
1345        drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1346                mode_set->x = x;
1347                mode_set->y = y;
1348        }
1349        mutex_unlock(&fb_helper->client.modeset_mutex);
1350}
1351
1352static int pan_display_atomic(struct fb_var_screeninfo *var,
1353                              struct fb_info *info)
1354{
1355        struct drm_fb_helper *fb_helper = info->par;
1356        int ret;
1357
1358        pan_set(fb_helper, var->xoffset, var->yoffset);
1359
1360        ret = drm_client_modeset_commit_force(&fb_helper->client);
1361        if (!ret) {
1362                info->var.xoffset = var->xoffset;
1363                info->var.yoffset = var->yoffset;
1364        } else
1365                pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1366
1367        return ret;
1368}
1369
1370static int pan_display_legacy(struct fb_var_screeninfo *var,
1371                              struct fb_info *info)
1372{
1373        struct drm_fb_helper *fb_helper = info->par;
1374        struct drm_client_dev *client = &fb_helper->client;
1375        struct drm_mode_set *modeset;
1376        int ret = 0;
1377
1378        mutex_lock(&client->modeset_mutex);
1379        drm_modeset_lock_all(fb_helper->dev);
1380        drm_client_for_each_modeset(modeset, client) {
1381                modeset->x = var->xoffset;
1382                modeset->y = var->yoffset;
1383
1384                if (modeset->num_connectors) {
1385                        ret = drm_mode_set_config_internal(modeset);
1386                        if (!ret) {
1387                                info->var.xoffset = var->xoffset;
1388                                info->var.yoffset = var->yoffset;
1389                        }
1390                }
1391        }
1392        drm_modeset_unlock_all(fb_helper->dev);
1393        mutex_unlock(&client->modeset_mutex);
1394
1395        return ret;
1396}
1397
1398/**
1399 * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1400 * @var: updated screen information
1401 * @info: fbdev registered by the helper
1402 */
1403int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1404                              struct fb_info *info)
1405{
1406        struct drm_fb_helper *fb_helper = info->par;
1407        struct drm_device *dev = fb_helper->dev;
1408        int ret;
1409
1410        if (oops_in_progress)
1411                return -EBUSY;
1412
1413        mutex_lock(&fb_helper->lock);
1414        if (!drm_master_internal_acquire(dev)) {
1415                ret = -EBUSY;
1416                goto unlock;
1417        }
1418
1419        if (drm_drv_uses_atomic_modeset(dev))
1420                ret = pan_display_atomic(var, info);
1421        else
1422                ret = pan_display_legacy(var, info);
1423
1424        drm_master_internal_release(dev);
1425unlock:
1426        mutex_unlock(&fb_helper->lock);
1427
1428        return ret;
1429}
1430EXPORT_SYMBOL(drm_fb_helper_pan_display);
1431
1432/*
1433 * Allocates the backing storage and sets up the fbdev info structure through
1434 * the ->fb_probe callback.
1435 */
1436static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1437                                         int preferred_bpp)
1438{
1439        struct drm_client_dev *client = &fb_helper->client;
1440        struct drm_device *dev = fb_helper->dev;
1441        int ret = 0;
1442        int crtc_count = 0;
1443        struct drm_connector_list_iter conn_iter;
1444        struct drm_fb_helper_surface_size sizes;
1445        struct drm_connector *connector;
1446        struct drm_mode_set *mode_set;
1447        int best_depth = 0;
1448
1449        memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1450        sizes.surface_depth = 24;
1451        sizes.surface_bpp = 32;
1452        sizes.fb_width = (u32)-1;
1453        sizes.fb_height = (u32)-1;
1454
1455        /*
1456         * If driver picks 8 or 16 by default use that for both depth/bpp
1457         * to begin with
1458         */
1459        if (preferred_bpp != sizes.surface_bpp)
1460                sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1461
1462        drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1463        drm_client_for_each_connector_iter(connector, &conn_iter) {
1464                struct drm_cmdline_mode *cmdline_mode;
1465
1466                cmdline_mode = &connector->cmdline_mode;
1467
1468                if (cmdline_mode->bpp_specified) {
1469                        switch (cmdline_mode->bpp) {
1470                        case 8:
1471                                sizes.surface_depth = sizes.surface_bpp = 8;
1472                                break;
1473                        case 15:
1474                                sizes.surface_depth = 15;
1475                                sizes.surface_bpp = 16;
1476                                break;
1477                        case 16:
1478                                sizes.surface_depth = sizes.surface_bpp = 16;
1479                                break;
1480                        case 24:
1481                                sizes.surface_depth = sizes.surface_bpp = 24;
1482                                break;
1483                        case 32:
1484                                sizes.surface_depth = 24;
1485                                sizes.surface_bpp = 32;
1486                                break;
1487                        }
1488                        break;
1489                }
1490        }
1491        drm_connector_list_iter_end(&conn_iter);
1492
1493        /*
1494         * If we run into a situation where, for example, the primary plane
1495         * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1496         * 16) we need to scale down the depth of the sizes we request.
1497         */
1498        mutex_lock(&client->modeset_mutex);
1499        drm_client_for_each_modeset(mode_set, client) {
1500                struct drm_crtc *crtc = mode_set->crtc;
1501                struct drm_plane *plane = crtc->primary;
1502                int j;
1503
1504                drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1505
1506                for (j = 0; j < plane->format_count; j++) {
1507                        const struct drm_format_info *fmt;
1508
1509                        fmt = drm_format_info(plane->format_types[j]);
1510
1511                        /*
1512                         * Do not consider YUV or other complicated formats
1513                         * for framebuffers. This means only legacy formats
1514                         * are supported (fmt->depth is a legacy field) but
1515                         * the framebuffer emulation can only deal with such
1516                         * formats, specifically RGB/BGA formats.
1517                         */
1518                        if (fmt->depth == 0)
1519                                continue;
1520
1521                        /* We found a perfect fit, great */
1522                        if (fmt->depth == sizes.surface_depth) {
1523                                best_depth = fmt->depth;
1524                                break;
1525                        }
1526
1527                        /* Skip depths above what we're looking for */
1528                        if (fmt->depth > sizes.surface_depth)
1529                                continue;
1530
1531                        /* Best depth found so far */
1532                        if (fmt->depth > best_depth)
1533                                best_depth = fmt->depth;
1534                }
1535        }
1536        if (sizes.surface_depth != best_depth && best_depth) {
1537                drm_info(dev, "requested bpp %d, scaled depth down to %d",
1538                         sizes.surface_bpp, best_depth);
1539                sizes.surface_depth = best_depth;
1540        }
1541
1542        /* first up get a count of crtcs now in use and new min/maxes width/heights */
1543        crtc_count = 0;
1544        drm_client_for_each_modeset(mode_set, client) {
1545                struct drm_display_mode *desired_mode;
1546                int x, y, j;
1547                /* in case of tile group, are we the last tile vert or horiz?
1548                 * If no tile group you are always the last one both vertically
1549                 * and horizontally
1550                 */
1551                bool lastv = true, lasth = true;
1552
1553                desired_mode = mode_set->mode;
1554
1555                if (!desired_mode)
1556                        continue;
1557
1558                crtc_count++;
1559
1560                x = mode_set->x;
1561                y = mode_set->y;
1562
1563                sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1564                sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1565
1566                for (j = 0; j < mode_set->num_connectors; j++) {
1567                        struct drm_connector *connector = mode_set->connectors[j];
1568
1569                        if (connector->has_tile &&
1570                            desired_mode->hdisplay == connector->tile_h_size &&
1571                            desired_mode->vdisplay == connector->tile_v_size) {
1572                                lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1573                                lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1574                                /* cloning to multiple tiles is just crazy-talk, so: */
1575                                break;
1576                        }
1577                }
1578
1579                if (lasth)
1580                        sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1581                if (lastv)
1582                        sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1583        }
1584        mutex_unlock(&client->modeset_mutex);
1585
1586        if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1587                drm_info(dev, "Cannot find any crtc or sizes\n");
1588
1589                /* First time: disable all crtc's.. */
1590                if (!fb_helper->deferred_setup)
1591                        drm_client_modeset_commit(client);
1592                return -EAGAIN;
1593        }
1594
1595        /* Handle our overallocation */
1596        sizes.surface_height *= drm_fbdev_overalloc;
1597        sizes.surface_height /= 100;
1598
1599        /* push down into drivers */
1600        ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1601        if (ret < 0)
1602                return ret;
1603
1604        strcpy(fb_helper->fb->comm, "[fbcon]");
1605        return 0;
1606}
1607
1608static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1609                                   uint32_t depth)
1610{
1611        info->fix.type = FB_TYPE_PACKED_PIXELS;
1612        info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1613                FB_VISUAL_TRUECOLOR;
1614        info->fix.mmio_start = 0;
1615        info->fix.mmio_len = 0;
1616        info->fix.type_aux = 0;
1617        info->fix.xpanstep = 1; /* doing it in hw */
1618        info->fix.ypanstep = 1; /* doing it in hw */
1619        info->fix.ywrapstep = 0;
1620        info->fix.accel = FB_ACCEL_NONE;
1621
1622        info->fix.line_length = pitch;
1623}
1624
1625static void drm_fb_helper_fill_var(struct fb_info *info,
1626                                   struct drm_fb_helper *fb_helper,
1627                                   uint32_t fb_width, uint32_t fb_height)
1628{
1629        struct drm_framebuffer *fb = fb_helper->fb;
1630
1631        WARN_ON((drm_format_info_block_width(fb->format, 0) > 1) ||
1632                (drm_format_info_block_height(fb->format, 0) > 1));
1633        info->pseudo_palette = fb_helper->pseudo_palette;
1634        info->var.xres_virtual = fb->width;
1635        info->var.yres_virtual = fb->height;
1636        info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1637        info->var.accel_flags = FB_ACCELF_TEXT;
1638        info->var.xoffset = 0;
1639        info->var.yoffset = 0;
1640        info->var.activate = FB_ACTIVATE_NOW;
1641
1642        drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
1643
1644        info->var.xres = fb_width;
1645        info->var.yres = fb_height;
1646}
1647
1648/**
1649 * drm_fb_helper_fill_info - initializes fbdev information
1650 * @info: fbdev instance to set up
1651 * @fb_helper: fb helper instance to use as template
1652 * @sizes: describes fbdev size and scanout surface size
1653 *
1654 * Sets up the variable and fixed fbdev metainformation from the given fb helper
1655 * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1656 *
1657 * Drivers should call this (or their equivalent setup code) from their
1658 * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1659 * backing storage framebuffer.
1660 */
1661void drm_fb_helper_fill_info(struct fb_info *info,
1662                             struct drm_fb_helper *fb_helper,
1663                             struct drm_fb_helper_surface_size *sizes)
1664{
1665        struct drm_framebuffer *fb = fb_helper->fb;
1666
1667        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
1668        drm_fb_helper_fill_var(info, fb_helper,
1669                               sizes->fb_width, sizes->fb_height);
1670
1671        info->par = fb_helper;
1672        snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
1673                 fb_helper->dev->driver->name);
1674
1675}
1676EXPORT_SYMBOL(drm_fb_helper_fill_info);
1677
1678/*
1679 * This is a continuation of drm_setup_crtcs() that sets up anything related
1680 * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1681 * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
1682 * So, any setup that touches those fields needs to be done here instead of in
1683 * drm_setup_crtcs().
1684 */
1685static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1686{
1687        struct drm_client_dev *client = &fb_helper->client;
1688        struct drm_connector_list_iter conn_iter;
1689        struct fb_info *info = fb_helper->fbdev;
1690        unsigned int rotation, sw_rotations = 0;
1691        struct drm_connector *connector;
1692        struct drm_mode_set *modeset;
1693
1694        mutex_lock(&client->modeset_mutex);
1695        drm_client_for_each_modeset(modeset, client) {
1696                if (!modeset->num_connectors)
1697                        continue;
1698
1699                modeset->fb = fb_helper->fb;
1700
1701                if (drm_client_rotation(modeset, &rotation))
1702                        /* Rotating in hardware, fbcon should not rotate */
1703                        sw_rotations |= DRM_MODE_ROTATE_0;
1704                else
1705                        sw_rotations |= rotation;
1706        }
1707        mutex_unlock(&client->modeset_mutex);
1708
1709        drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1710        drm_client_for_each_connector_iter(connector, &conn_iter) {
1711
1712                /* use first connected connector for the physical dimensions */
1713                if (connector->status == connector_status_connected) {
1714                        info->var.width = connector->display_info.width_mm;
1715                        info->var.height = connector->display_info.height_mm;
1716                        break;
1717                }
1718        }
1719        drm_connector_list_iter_end(&conn_iter);
1720
1721        switch (sw_rotations) {
1722        case DRM_MODE_ROTATE_0:
1723                info->fbcon_rotate_hint = FB_ROTATE_UR;
1724                break;
1725        case DRM_MODE_ROTATE_90:
1726                info->fbcon_rotate_hint = FB_ROTATE_CCW;
1727                break;
1728        case DRM_MODE_ROTATE_180:
1729                info->fbcon_rotate_hint = FB_ROTATE_UD;
1730                break;
1731        case DRM_MODE_ROTATE_270:
1732                info->fbcon_rotate_hint = FB_ROTATE_CW;
1733                break;
1734        default:
1735                /*
1736                 * Multiple bits are set / multiple rotations requested
1737                 * fbcon cannot handle separate rotation settings per
1738                 * output, so fallback to unrotated.
1739                 */
1740                info->fbcon_rotate_hint = FB_ROTATE_UR;
1741        }
1742}
1743
1744/* Note: Drops fb_helper->lock before returning. */
1745static int
1746__drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
1747                                          int bpp_sel)
1748{
1749        struct drm_device *dev = fb_helper->dev;
1750        struct fb_info *info;
1751        unsigned int width, height;
1752        int ret;
1753
1754        width = dev->mode_config.max_width;
1755        height = dev->mode_config.max_height;
1756
1757        drm_client_modeset_probe(&fb_helper->client, width, height);
1758        ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
1759        if (ret < 0) {
1760                if (ret == -EAGAIN) {
1761                        fb_helper->preferred_bpp = bpp_sel;
1762                        fb_helper->deferred_setup = true;
1763                        ret = 0;
1764                }
1765                mutex_unlock(&fb_helper->lock);
1766
1767                return ret;
1768        }
1769        drm_setup_crtcs_fb(fb_helper);
1770
1771        fb_helper->deferred_setup = false;
1772
1773        info = fb_helper->fbdev;
1774        info->var.pixclock = 0;
1775        /* Shamelessly allow physical address leaking to userspace */
1776#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1777        if (!drm_leak_fbdev_smem)
1778#endif
1779                /* don't leak any physical addresses to userspace */
1780                info->flags |= FBINFO_HIDE_SMEM_START;
1781
1782        /* Need to drop locks to avoid recursive deadlock in
1783         * register_framebuffer. This is ok because the only thing left to do is
1784         * register the fbdev emulation instance in kernel_fb_helper_list. */
1785        mutex_unlock(&fb_helper->lock);
1786
1787        ret = register_framebuffer(info);
1788        if (ret < 0)
1789                return ret;
1790
1791        dev_info(dev->dev, "fb%d: %s frame buffer device\n",
1792                 info->node, info->fix.id);
1793
1794        mutex_lock(&kernel_fb_helper_lock);
1795        if (list_empty(&kernel_fb_helper_list))
1796                register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
1797
1798        list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
1799        mutex_unlock(&kernel_fb_helper_lock);
1800
1801        return 0;
1802}
1803
1804/**
1805 * drm_fb_helper_initial_config - setup a sane initial connector configuration
1806 * @fb_helper: fb_helper device struct
1807 * @bpp_sel: bpp value to use for the framebuffer configuration
1808 *
1809 * Scans the CRTCs and connectors and tries to put together an initial setup.
1810 * At the moment, this is a cloned configuration across all heads with
1811 * a new framebuffer object as the backing store.
1812 *
1813 * Note that this also registers the fbdev and so allows userspace to call into
1814 * the driver through the fbdev interfaces.
1815 *
1816 * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1817 * to let the driver allocate and initialize the fbdev info structure and the
1818 * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1819 * as a helper to setup simple default values for the fbdev info structure.
1820 *
1821 * HANG DEBUGGING:
1822 *
1823 * When you have fbcon support built-in or already loaded, this function will do
1824 * a full modeset to setup the fbdev console. Due to locking misdesign in the
1825 * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1826 * console_lock. Until console_unlock is called no dmesg lines will be sent out
1827 * to consoles, not even serial console. This means when your driver crashes,
1828 * you will see absolutely nothing else but a system stuck in this function,
1829 * with no further output. Any kind of printk() you place within your own driver
1830 * or in the drm core modeset code will also never show up.
1831 *
1832 * Standard debug practice is to run the fbcon setup without taking the
1833 * console_lock as a hack, to be able to see backtraces and crashes on the
1834 * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1835 * cmdline option.
1836 *
1837 * The other option is to just disable fbdev emulation since very likely the
1838 * first modeset from userspace will crash in the same way, and is even easier
1839 * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1840 * kernel cmdline option.
1841 *
1842 * RETURNS:
1843 * Zero if everything went ok, nonzero otherwise.
1844 */
1845int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
1846{
1847        int ret;
1848
1849        if (!drm_fbdev_emulation)
1850                return 0;
1851
1852        mutex_lock(&fb_helper->lock);
1853        ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
1854
1855        return ret;
1856}
1857EXPORT_SYMBOL(drm_fb_helper_initial_config);
1858
1859/**
1860 * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1861 *                               probing all the outputs attached to the fb
1862 * @fb_helper: driver-allocated fbdev helper, can be NULL
1863 *
1864 * Scan the connectors attached to the fb_helper and try to put together a
1865 * setup after notification of a change in output configuration.
1866 *
1867 * Called at runtime, takes the mode config locks to be able to check/change the
1868 * modeset configuration. Must be run from process context (which usually means
1869 * either the output polling work or a work item launched from the driver's
1870 * hotplug interrupt).
1871 *
1872 * Note that drivers may call this even before calling
1873 * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1874 * for a race-free fbcon setup and will make sure that the fbdev emulation will
1875 * not miss any hotplug events.
1876 *
1877 * RETURNS:
1878 * 0 on success and a non-zero error code otherwise.
1879 */
1880int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1881{
1882        int err = 0;
1883
1884        if (!drm_fbdev_emulation || !fb_helper)
1885                return 0;
1886
1887        mutex_lock(&fb_helper->lock);
1888        if (fb_helper->deferred_setup) {
1889                err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
1890                                fb_helper->preferred_bpp);
1891                return err;
1892        }
1893
1894        if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
1895                fb_helper->delayed_hotplug = true;
1896                mutex_unlock(&fb_helper->lock);
1897                return err;
1898        }
1899
1900        drm_master_internal_release(fb_helper->dev);
1901
1902        drm_dbg_kms(fb_helper->dev, "\n");
1903
1904        drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
1905        drm_setup_crtcs_fb(fb_helper);
1906        mutex_unlock(&fb_helper->lock);
1907
1908        drm_fb_helper_set_par(fb_helper->fbdev);
1909
1910        return 0;
1911}
1912EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1913
1914/**
1915 * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
1916 * @dev: DRM device
1917 *
1918 * This function can be used as the &drm_driver->lastclose callback for drivers
1919 * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
1920 */
1921void drm_fb_helper_lastclose(struct drm_device *dev)
1922{
1923        drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
1924}
1925EXPORT_SYMBOL(drm_fb_helper_lastclose);
1926
1927/**
1928 * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
1929 *                                     helper for fbdev emulation
1930 * @dev: DRM device
1931 *
1932 * This function can be used as the
1933 * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
1934 * need to call drm_fb_helper_hotplug_event().
1935 */
1936void drm_fb_helper_output_poll_changed(struct drm_device *dev)
1937{
1938        drm_fb_helper_hotplug_event(dev->fb_helper);
1939}
1940EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
1941
1942/* @user: 1=userspace, 0=fbcon */
1943static int drm_fbdev_fb_open(struct fb_info *info, int user)
1944{
1945        struct drm_fb_helper *fb_helper = info->par;
1946
1947        /* No need to take a ref for fbcon because it unbinds on unregister */
1948        if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
1949                return -ENODEV;
1950
1951        return 0;
1952}
1953
1954static int drm_fbdev_fb_release(struct fb_info *info, int user)
1955{
1956        struct drm_fb_helper *fb_helper = info->par;
1957
1958        if (user)
1959                module_put(fb_helper->dev->driver->fops->owner);
1960
1961        return 0;
1962}
1963
1964static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
1965{
1966        struct fb_info *fbi = fb_helper->fbdev;
1967        void *shadow = NULL;
1968
1969        if (!fb_helper->dev)
1970                return;
1971
1972        if (fbi && fbi->fbdefio) {
1973                fb_deferred_io_cleanup(fbi);
1974                shadow = fbi->screen_buffer;
1975        }
1976
1977        drm_fb_helper_fini(fb_helper);
1978
1979        vfree(shadow);
1980
1981        drm_client_framebuffer_delete(fb_helper->buffer);
1982}
1983
1984static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
1985{
1986        drm_fbdev_cleanup(fb_helper);
1987        drm_client_release(&fb_helper->client);
1988        kfree(fb_helper);
1989}
1990
1991/*
1992 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
1993 * unregister_framebuffer() or fb_release().
1994 */
1995static void drm_fbdev_fb_destroy(struct fb_info *info)
1996{
1997        drm_fbdev_release(info->par);
1998}
1999
2000static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
2001{
2002        struct drm_fb_helper *fb_helper = info->par;
2003
2004        if (fb_helper->dev->driver->gem_prime_mmap)
2005                return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
2006        else
2007                return -ENODEV;
2008}
2009
2010static const struct fb_ops drm_fbdev_fb_ops = {
2011        .owner          = THIS_MODULE,
2012        DRM_FB_HELPER_DEFAULT_OPS,
2013        .fb_open        = drm_fbdev_fb_open,
2014        .fb_release     = drm_fbdev_fb_release,
2015        .fb_destroy     = drm_fbdev_fb_destroy,
2016        .fb_mmap        = drm_fbdev_fb_mmap,
2017        .fb_read        = drm_fb_helper_sys_read,
2018        .fb_write       = drm_fb_helper_sys_write,
2019        .fb_fillrect    = drm_fb_helper_sys_fillrect,
2020        .fb_copyarea    = drm_fb_helper_sys_copyarea,
2021        .fb_imageblit   = drm_fb_helper_sys_imageblit,
2022};
2023
2024static struct fb_deferred_io drm_fbdev_defio = {
2025        .delay          = HZ / 20,
2026        .deferred_io    = drm_fb_helper_deferred_io,
2027};
2028
2029/*
2030 * This function uses the client API to create a framebuffer backed by a dumb buffer.
2031 *
2032 * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
2033 * fb_copyarea, fb_imageblit.
2034 */
2035static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
2036                                       struct drm_fb_helper_surface_size *sizes)
2037{
2038        struct drm_client_dev *client = &fb_helper->client;
2039        struct drm_device *dev = fb_helper->dev;
2040        struct drm_client_buffer *buffer;
2041        struct drm_framebuffer *fb;
2042        struct fb_info *fbi;
2043        u32 format;
2044        void *vaddr;
2045
2046        drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
2047                    sizes->surface_width, sizes->surface_height,
2048                    sizes->surface_bpp);
2049
2050        format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
2051        buffer = drm_client_framebuffer_create(client, sizes->surface_width,
2052                                               sizes->surface_height, format);
2053        if (IS_ERR(buffer))
2054                return PTR_ERR(buffer);
2055
2056        fb_helper->buffer = buffer;
2057        fb_helper->fb = buffer->fb;
2058        fb = buffer->fb;
2059
2060        fbi = drm_fb_helper_alloc_fbi(fb_helper);
2061        if (IS_ERR(fbi))
2062                return PTR_ERR(fbi);
2063
2064        fbi->fbops = &drm_fbdev_fb_ops;
2065        fbi->screen_size = fb->height * fb->pitches[0];
2066        fbi->fix.smem_len = fbi->screen_size;
2067
2068        drm_fb_helper_fill_info(fbi, fb_helper, sizes);
2069
2070        if (drm_fbdev_use_shadow_fb(fb_helper)) {
2071                fbi->screen_buffer = vzalloc(fbi->screen_size);
2072                if (!fbi->screen_buffer)
2073                        return -ENOMEM;
2074
2075                fbi->fbdefio = &drm_fbdev_defio;
2076
2077                fb_deferred_io_init(fbi);
2078        } else {
2079                /* buffer is mapped for HW framebuffer */
2080                vaddr = drm_client_buffer_vmap(fb_helper->buffer);
2081                if (IS_ERR(vaddr))
2082                        return PTR_ERR(vaddr);
2083
2084                fbi->screen_buffer = vaddr;
2085                /* Shamelessly leak the physical address to user-space */
2086#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2087                if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
2088                        fbi->fix.smem_start =
2089                                page_to_phys(virt_to_page(fbi->screen_buffer));
2090#endif
2091        }
2092
2093        return 0;
2094}
2095
2096static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
2097        .fb_probe = drm_fb_helper_generic_probe,
2098};
2099
2100static void drm_fbdev_client_unregister(struct drm_client_dev *client)
2101{
2102        struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2103
2104        if (fb_helper->fbdev)
2105                /* drm_fbdev_fb_destroy() takes care of cleanup */
2106                drm_fb_helper_unregister_fbi(fb_helper);
2107        else
2108                drm_fbdev_release(fb_helper);
2109}
2110
2111static int drm_fbdev_client_restore(struct drm_client_dev *client)
2112{
2113        drm_fb_helper_lastclose(client->dev);
2114
2115        return 0;
2116}
2117
2118static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
2119{
2120        struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2121        struct drm_device *dev = client->dev;
2122        int ret;
2123
2124        /* Setup is not retried if it has failed */
2125        if (!fb_helper->dev && fb_helper->funcs)
2126                return 0;
2127
2128        if (dev->fb_helper)
2129                return drm_fb_helper_hotplug_event(dev->fb_helper);
2130
2131        if (!dev->mode_config.num_connector) {
2132                drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
2133                return 0;
2134        }
2135
2136        drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
2137
2138        ret = drm_fb_helper_init(dev, fb_helper, 0);
2139        if (ret)
2140                goto err;
2141
2142        if (!drm_drv_uses_atomic_modeset(dev))
2143                drm_helper_disable_unused_functions(dev);
2144
2145        ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
2146        if (ret)
2147                goto err_cleanup;
2148
2149        return 0;
2150
2151err_cleanup:
2152        drm_fbdev_cleanup(fb_helper);
2153err:
2154        fb_helper->dev = NULL;
2155        fb_helper->fbdev = NULL;
2156
2157        drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
2158
2159        return ret;
2160}
2161
2162static const struct drm_client_funcs drm_fbdev_client_funcs = {
2163        .owner          = THIS_MODULE,
2164        .unregister     = drm_fbdev_client_unregister,
2165        .restore        = drm_fbdev_client_restore,
2166        .hotplug        = drm_fbdev_client_hotplug,
2167};
2168
2169/**
2170 * drm_fbdev_generic_setup() - Setup generic fbdev emulation
2171 * @dev: DRM device
2172 * @preferred_bpp: Preferred bits per pixel for the device.
2173 *                 @dev->mode_config.preferred_depth is used if this is zero.
2174 *
2175 * This function sets up generic fbdev emulation for drivers that supports
2176 * dumb buffers with a virtual address and that can be mmap'ed.
2177 *
2178 * Restore, hotplug events and teardown are all taken care of. Drivers that do
2179 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
2180 * Simple drivers might use drm_mode_config_helper_suspend().
2181 *
2182 * Drivers that set the dirty callback on their framebuffer will get a shadow
2183 * fbdev buffer that is blitted onto the real buffer. This is done in order to
2184 * make deferred I/O work with all kinds of buffers. A shadow buffer can be
2185 * requested explicitly by setting struct drm_mode_config.prefer_shadow or
2186 * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is
2187 * required to use generic fbdev emulation with SHMEM helpers.
2188 *
2189 * This function is safe to call even when there are no connectors present.
2190 * Setup will be retried on the next hotplug event.
2191 *
2192 * The fbdev is destroyed by drm_dev_unregister().
2193 *
2194 * Returns:
2195 * Zero on success or negative error code on failure.
2196 */
2197int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
2198{
2199        struct drm_fb_helper *fb_helper;
2200        int ret;
2201
2202        WARN(dev->fb_helper, "fb_helper is already set!\n");
2203
2204        if (!drm_fbdev_emulation)
2205                return 0;
2206
2207        fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
2208        if (!fb_helper)
2209                return -ENOMEM;
2210
2211        ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
2212        if (ret) {
2213                kfree(fb_helper);
2214                drm_err(dev, "Failed to register client: %d\n", ret);
2215                return ret;
2216        }
2217
2218        if (!preferred_bpp)
2219                preferred_bpp = dev->mode_config.preferred_depth;
2220        if (!preferred_bpp)
2221                preferred_bpp = 32;
2222        fb_helper->preferred_bpp = preferred_bpp;
2223
2224        ret = drm_fbdev_client_hotplug(&fb_helper->client);
2225        if (ret)
2226                drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
2227
2228        drm_client_register(&fb_helper->client);
2229
2230        return 0;
2231}
2232EXPORT_SYMBOL(drm_fbdev_generic_setup);
2233
2234/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
2235 * but the module doesn't depend on any fb console symbols.  At least
2236 * attempt to load fbcon to avoid leaving the system without a usable console.
2237 */
2238int __init drm_fb_helper_modinit(void)
2239{
2240#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
2241        const char name[] = "fbcon";
2242        struct module *fbcon;
2243
2244        mutex_lock(&module_mutex);
2245        fbcon = find_module(name);
2246        mutex_unlock(&module_mutex);
2247
2248        if (!fbcon)
2249                request_module_nowait(name);
2250#endif
2251        return 0;
2252}
2253EXPORT_SYMBOL(drm_fb_helper_modinit);
2254