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
 230static int
 231__drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper,
 232					    bool force)
 233{
 234	bool do_delayed;
 235	int ret;
 236
 237	if (!drm_fbdev_emulation || !fb_helper)
 238		return -ENODEV;
 239
 240	if (READ_ONCE(fb_helper->deferred_setup))
 241		return 0;
 242
 243	mutex_lock(&fb_helper->lock);
 244	if (force) {
 245		/*
 246		 * Yes this is the _locked version which expects the master lock
 247		 * to be held. But for forced restores we're intentionally
 248		 * racing here, see drm_fb_helper_set_par().
 249		 */
 250		ret = drm_client_modeset_commit_locked(&fb_helper->client);
 251	} else {
 252		ret = drm_client_modeset_commit(&fb_helper->client);
 253	}
 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
 266/**
 267 * drm_fb_helper_restore_fbdev_mode_unlocked - restore fbdev configuration
 268 * @fb_helper: driver-allocated fbdev helper, can be NULL
 269 *
 270 * This should be called from driver's drm &drm_driver.lastclose callback
 271 * when implementing an fbcon on top of kms using this helper. This ensures that
 272 * the user isn't greeted with a black screen when e.g. X dies.
 273 *
 274 * RETURNS:
 275 * Zero if everything went ok, negative error code otherwise.
 276 */
 277int drm_fb_helper_restore_fbdev_mode_unlocked(struct drm_fb_helper *fb_helper)
 278{
 279	return __drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, false);
 280}
 281EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode_unlocked);
 282
 283#ifdef CONFIG_MAGIC_SYSRQ
 284/*
 285 * restore fbcon display for all kms driver's using this helper, used for sysrq
 286 * and panic handling.
 287 */
 288static bool drm_fb_helper_force_kernel_mode(void)
 289{
 290	bool ret, error = false;
 291	struct drm_fb_helper *helper;
 292
 293	if (list_empty(&kernel_fb_helper_list))
 294		return false;
 295
 296	list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
 297		struct drm_device *dev = helper->dev;
 298
 299		if (dev->switch_power_state == DRM_SWITCH_POWER_OFF)
 300			continue;
 301
 302		mutex_lock(&helper->lock);
 303		ret = drm_client_modeset_commit_locked(&helper->client);
 304		if (ret)
 305			error = true;
 306		mutex_unlock(&helper->lock);
 307	}
 308	return error;
 309}
 310
 311static void drm_fb_helper_restore_work_fn(struct work_struct *ignored)
 312{
 313	bool ret;
 314
 315	ret = drm_fb_helper_force_kernel_mode();
 316	if (ret == true)
 317		DRM_ERROR("Failed to restore crtc configuration\n");
 318}
 319static DECLARE_WORK(drm_fb_helper_restore_work, drm_fb_helper_restore_work_fn);
 320
 321static void drm_fb_helper_sysrq(int dummy1)
 322{
 323	schedule_work(&drm_fb_helper_restore_work);
 324}
 325
 326static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 327	.handler = drm_fb_helper_sysrq,
 328	.help_msg = "force-fb(V)",
 329	.action_msg = "Restore framebuffer console",
 330};
 331#else
 332static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = { };
 333#endif
 334
 335static void drm_fb_helper_dpms(struct fb_info *info, int dpms_mode)
 336{
 337	struct drm_fb_helper *fb_helper = info->par;
 338
 339	mutex_lock(&fb_helper->lock);
 340	drm_client_modeset_dpms(&fb_helper->client, dpms_mode);
 341	mutex_unlock(&fb_helper->lock);
 342}
 343
 344/**
 345 * drm_fb_helper_blank - implementation for &fb_ops.fb_blank
 346 * @blank: desired blanking state
 347 * @info: fbdev registered by the helper
 348 */
 349int drm_fb_helper_blank(int blank, struct fb_info *info)
 350{
 351	if (oops_in_progress)
 352		return -EBUSY;
 353
 354	switch (blank) {
 355	/* Display: On; HSync: On, VSync: On */
 356	case FB_BLANK_UNBLANK:
 357		drm_fb_helper_dpms(info, DRM_MODE_DPMS_ON);
 358		break;
 359	/* Display: Off; HSync: On, VSync: On */
 360	case FB_BLANK_NORMAL:
 361		drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 362		break;
 363	/* Display: Off; HSync: Off, VSync: On */
 364	case FB_BLANK_HSYNC_SUSPEND:
 365		drm_fb_helper_dpms(info, DRM_MODE_DPMS_STANDBY);
 366		break;
 367	/* Display: Off; HSync: On, VSync: Off */
 368	case FB_BLANK_VSYNC_SUSPEND:
 369		drm_fb_helper_dpms(info, DRM_MODE_DPMS_SUSPEND);
 370		break;
 371	/* Display: Off; HSync: Off, VSync: Off */
 372	case FB_BLANK_POWERDOWN:
 373		drm_fb_helper_dpms(info, DRM_MODE_DPMS_OFF);
 374		break;
 375	}
 376	return 0;
 377}
 378EXPORT_SYMBOL(drm_fb_helper_blank);
 379
 380static void drm_fb_helper_resume_worker(struct work_struct *work)
 381{
 382	struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 383						    resume_work);
 384
 385	console_lock();
 386	fb_set_suspend(helper->fbdev, 0);
 387	console_unlock();
 388}
 389
 390static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
 391					  struct drm_clip_rect *clip)
 
 392{
 393	struct drm_framebuffer *fb = fb_helper->fb;
 394	unsigned int cpp = fb->format->cpp[0];
 395	size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
 396	void *src = fb_helper->fbdev->screen_buffer + offset;
 397	void *dst = fb_helper->buffer->vaddr + offset;
 398	size_t len = (clip->x2 - clip->x1) * cpp;
 399	unsigned int y;
 400
 401	for (y = clip->y1; y < clip->y2; y++) {
 402		if (!fb_helper->dev->mode_config.fbdev_use_iomem)
 403			memcpy(dst, src, len);
 404		else
 405			memcpy_toio((void __iomem *)dst, src, len);
 406
 
 
 
 407		src += fb->pitches[0];
 408		dst += fb->pitches[0];
 409	}
 410}
 411
 412static void drm_fb_helper_dirty_work(struct work_struct *work)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 413{
 414	struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
 415						    dirty_work);
 416	struct drm_clip_rect *clip = &helper->dirty_clip;
 
 417	struct drm_clip_rect clip_copy;
 418	unsigned long flags;
 419	void *vaddr;
 420
 421	spin_lock_irqsave(&helper->dirty_lock, flags);
 422	clip_copy = *clip;
 423	clip->x1 = clip->y1 = ~0;
 424	clip->x2 = clip->y2 = 0;
 425	spin_unlock_irqrestore(&helper->dirty_lock, flags);
 426
 427	/* call dirty callback only when it has been really touched */
 428	if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
 
 429
 430		/* Generic fbdev uses a shadow buffer */
 431		if (helper->buffer) {
 432			vaddr = drm_client_buffer_vmap(helper->buffer);
 433			if (IS_ERR(vaddr))
 434				return;
 435			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
 436		}
 437		if (helper->fb->funcs->dirty)
 438			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
 439						 &clip_copy, 1);
 440
 441		if (helper->buffer)
 442			drm_client_buffer_vunmap(helper->buffer);
 
 
 443	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 444}
 445
 446/**
 447 * drm_fb_helper_prepare - setup a drm_fb_helper structure
 448 * @dev: DRM device
 449 * @helper: driver-allocated fbdev helper structure to set up
 450 * @funcs: pointer to structure of functions associate with this helper
 451 *
 452 * Sets up the bare minimum to make the framebuffer helper usable. This is
 453 * useful to implement race-free initialization of the polling helpers.
 454 */
 455void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 456			   const struct drm_fb_helper_funcs *funcs)
 457{
 458	INIT_LIST_HEAD(&helper->kernel_fb_list);
 459	spin_lock_init(&helper->dirty_lock);
 460	INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
 461	INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
 462	helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
 463	mutex_init(&helper->lock);
 464	helper->funcs = funcs;
 465	helper->dev = dev;
 466}
 467EXPORT_SYMBOL(drm_fb_helper_prepare);
 468
 469/**
 470 * drm_fb_helper_init - initialize a &struct drm_fb_helper
 471 * @dev: drm device
 472 * @fb_helper: driver-allocated fbdev helper structure to initialize
 473 *
 474 * This allocates the structures for the fbdev helper with the given limits.
 475 * Note that this won't yet touch the hardware (through the driver interfaces)
 476 * nor register the fbdev. This is only done in drm_fb_helper_initial_config()
 477 * to allow driver writes more control over the exact init sequence.
 478 *
 479 * Drivers must call drm_fb_helper_prepare() before calling this function.
 480 *
 481 * RETURNS:
 482 * Zero if everything went ok, nonzero otherwise.
 483 */
 484int drm_fb_helper_init(struct drm_device *dev,
 485		       struct drm_fb_helper *fb_helper)
 486{
 487	int ret;
 488
 489	if (!drm_fbdev_emulation) {
 490		dev->fb_helper = fb_helper;
 491		return 0;
 492	}
 493
 494	/*
 495	 * If this is not the generic fbdev client, initialize a drm_client
 496	 * without callbacks so we can use the modesets.
 497	 */
 498	if (!fb_helper->client.funcs) {
 499		ret = drm_client_init(dev, &fb_helper->client, "drm_fb_helper", NULL);
 500		if (ret)
 501			return ret;
 502	}
 503
 504	dev->fb_helper = fb_helper;
 505
 506	return 0;
 507}
 508EXPORT_SYMBOL(drm_fb_helper_init);
 509
 510/**
 511 * drm_fb_helper_alloc_fbi - allocate fb_info and some of its members
 512 * @fb_helper: driver-allocated fbdev helper
 513 *
 514 * A helper to alloc fb_info and the members cmap and apertures. Called
 515 * by the driver within the fb_probe fb_helper callback function. Drivers do not
 516 * need to release the allocated fb_info structure themselves, this is
 517 * automatically done when calling drm_fb_helper_fini().
 518 *
 519 * RETURNS:
 520 * fb_info pointer if things went okay, pointer containing error code
 521 * otherwise
 522 */
 523struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
 524{
 525	struct device *dev = fb_helper->dev->dev;
 526	struct fb_info *info;
 527	int ret;
 528
 529	info = framebuffer_alloc(0, dev);
 530	if (!info)
 531		return ERR_PTR(-ENOMEM);
 532
 533	ret = fb_alloc_cmap(&info->cmap, 256, 0);
 534	if (ret)
 535		goto err_release;
 536
 537	/*
 538	 * TODO: We really should be smarter here and alloc an apperture
 539	 * for each IORESOURCE_MEM resource helper->dev->dev has and also
 540	 * init the ranges of the appertures based on the resources.
 541	 * Note some drivers currently count on there being only 1 empty
 542	 * aperture and fill this themselves, these will need to be dealt
 543	 * with somehow when fixing this.
 544	 */
 545	info->apertures = alloc_apertures(1);
 546	if (!info->apertures) {
 547		ret = -ENOMEM;
 548		goto err_free_cmap;
 549	}
 550
 551	fb_helper->fbdev = info;
 552	info->skip_vt_switch = true;
 553
 554	return info;
 555
 556err_free_cmap:
 557	fb_dealloc_cmap(&info->cmap);
 558err_release:
 559	framebuffer_release(info);
 560	return ERR_PTR(ret);
 561}
 562EXPORT_SYMBOL(drm_fb_helper_alloc_fbi);
 563
 564/**
 565 * drm_fb_helper_unregister_fbi - unregister fb_info framebuffer device
 566 * @fb_helper: driver-allocated fbdev helper, can be NULL
 567 *
 568 * A wrapper around unregister_framebuffer, to release the fb_info
 569 * framebuffer device. This must be called before releasing all resources for
 570 * @fb_helper by calling drm_fb_helper_fini().
 571 */
 572void drm_fb_helper_unregister_fbi(struct drm_fb_helper *fb_helper)
 573{
 574	if (fb_helper && fb_helper->fbdev)
 575		unregister_framebuffer(fb_helper->fbdev);
 576}
 577EXPORT_SYMBOL(drm_fb_helper_unregister_fbi);
 578
 579/**
 580 * drm_fb_helper_fini - finialize a &struct drm_fb_helper
 581 * @fb_helper: driver-allocated fbdev helper, can be NULL
 582 *
 583 * This cleans up all remaining resources associated with @fb_helper.
 584 */
 585void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
 586{
 587	struct fb_info *info;
 588
 589	if (!fb_helper)
 590		return;
 591
 592	fb_helper->dev->fb_helper = NULL;
 593
 594	if (!drm_fbdev_emulation)
 595		return;
 596
 597	cancel_work_sync(&fb_helper->resume_work);
 598	cancel_work_sync(&fb_helper->dirty_work);
 599
 600	info = fb_helper->fbdev;
 601	if (info) {
 602		if (info->cmap.len)
 603			fb_dealloc_cmap(&info->cmap);
 604		framebuffer_release(info);
 605	}
 606	fb_helper->fbdev = NULL;
 607
 608	mutex_lock(&kernel_fb_helper_lock);
 609	if (!list_empty(&fb_helper->kernel_fb_list)) {
 610		list_del(&fb_helper->kernel_fb_list);
 611		if (list_empty(&kernel_fb_helper_list))
 612			unregister_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
 613	}
 614	mutex_unlock(&kernel_fb_helper_lock);
 615
 616	mutex_destroy(&fb_helper->lock);
 617
 618	if (!fb_helper->client.funcs)
 619		drm_client_release(&fb_helper->client);
 620}
 621EXPORT_SYMBOL(drm_fb_helper_fini);
 622
 623static bool drm_fbdev_use_shadow_fb(struct drm_fb_helper *fb_helper)
 624{
 625	struct drm_device *dev = fb_helper->dev;
 626	struct drm_framebuffer *fb = fb_helper->fb;
 627
 628	return dev->mode_config.prefer_shadow_fbdev ||
 629	       dev->mode_config.prefer_shadow ||
 630	       fb->funcs->dirty;
 631}
 632
 633static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y,
 634				u32 width, u32 height)
 635{
 636	struct drm_fb_helper *helper = info->par;
 637	struct drm_clip_rect *clip = &helper->dirty_clip;
 638	unsigned long flags;
 639
 640	if (!drm_fbdev_use_shadow_fb(helper))
 641		return;
 642
 643	spin_lock_irqsave(&helper->dirty_lock, flags);
 644	clip->x1 = min_t(u32, clip->x1, x);
 645	clip->y1 = min_t(u32, clip->y1, y);
 646	clip->x2 = max_t(u32, clip->x2, x + width);
 647	clip->y2 = max_t(u32, clip->y2, y + height);
 648	spin_unlock_irqrestore(&helper->dirty_lock, flags);
 649
 650	schedule_work(&helper->dirty_work);
 651}
 652
 653/**
 654 * drm_fb_helper_deferred_io() - fbdev deferred_io callback function
 655 * @info: fb_info struct pointer
 656 * @pagelist: list of dirty mmap framebuffer pages
 657 *
 658 * This function is used as the &fb_deferred_io.deferred_io
 659 * callback function for flushing the fbdev mmap writes.
 660 */
 661void drm_fb_helper_deferred_io(struct fb_info *info,
 662			       struct list_head *pagelist)
 663{
 664	unsigned long start, end, min, max;
 665	struct page *page;
 666	u32 y1, y2;
 667
 668	min = ULONG_MAX;
 669	max = 0;
 670	list_for_each_entry(page, pagelist, lru) {
 671		start = page->index << PAGE_SHIFT;
 672		end = start + PAGE_SIZE - 1;
 673		min = min(min, start);
 674		max = max(max, end);
 675	}
 676
 677	if (min < max) {
 678		y1 = min / info->fix.line_length;
 679		y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length),
 680			   info->var.yres);
 681		drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1);
 682	}
 683}
 684EXPORT_SYMBOL(drm_fb_helper_deferred_io);
 685
 686/**
 687 * drm_fb_helper_sys_read - wrapper around fb_sys_read
 688 * @info: fb_info struct pointer
 689 * @buf: userspace buffer to read from framebuffer memory
 690 * @count: number of bytes to read from framebuffer memory
 691 * @ppos: read offset within framebuffer memory
 692 *
 693 * A wrapper around fb_sys_read implemented by fbdev core
 694 */
 695ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
 696			       size_t count, loff_t *ppos)
 697{
 698	return fb_sys_read(info, buf, count, ppos);
 699}
 700EXPORT_SYMBOL(drm_fb_helper_sys_read);
 701
 702/**
 703 * drm_fb_helper_sys_write - wrapper around fb_sys_write
 704 * @info: fb_info struct pointer
 705 * @buf: userspace buffer to write to framebuffer memory
 706 * @count: number of bytes to write to framebuffer memory
 707 * @ppos: write offset within framebuffer memory
 708 *
 709 * A wrapper around fb_sys_write implemented by fbdev core
 710 */
 711ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
 712				size_t count, loff_t *ppos)
 713{
 714	ssize_t ret;
 715
 716	ret = fb_sys_write(info, buf, count, ppos);
 717	if (ret > 0)
 718		drm_fb_helper_dirty(info, 0, 0, info->var.xres,
 719				    info->var.yres);
 720
 721	return ret;
 722}
 723EXPORT_SYMBOL(drm_fb_helper_sys_write);
 724
 725/**
 726 * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
 727 * @info: fbdev registered by the helper
 728 * @rect: info about rectangle to fill
 729 *
 730 * A wrapper around sys_fillrect implemented by fbdev core
 731 */
 732void drm_fb_helper_sys_fillrect(struct fb_info *info,
 733				const struct fb_fillrect *rect)
 734{
 735	sys_fillrect(info, rect);
 736	drm_fb_helper_dirty(info, rect->dx, rect->dy,
 737			    rect->width, rect->height);
 738}
 739EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
 740
 741/**
 742 * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
 743 * @info: fbdev registered by the helper
 744 * @area: info about area to copy
 745 *
 746 * A wrapper around sys_copyarea implemented by fbdev core
 747 */
 748void drm_fb_helper_sys_copyarea(struct fb_info *info,
 749				const struct fb_copyarea *area)
 750{
 751	sys_copyarea(info, area);
 752	drm_fb_helper_dirty(info, area->dx, area->dy,
 753			    area->width, area->height);
 754}
 755EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
 756
 757/**
 758 * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
 759 * @info: fbdev registered by the helper
 760 * @image: info about image to blit
 761 *
 762 * A wrapper around sys_imageblit implemented by fbdev core
 763 */
 764void drm_fb_helper_sys_imageblit(struct fb_info *info,
 765				 const struct fb_image *image)
 766{
 767	sys_imageblit(info, image);
 768	drm_fb_helper_dirty(info, image->dx, image->dy,
 769			    image->width, image->height);
 770}
 771EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 772
 773/**
 774 * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
 775 * @info: fbdev registered by the helper
 776 * @rect: info about rectangle to fill
 777 *
 778 * A wrapper around cfb_fillrect implemented by fbdev core
 779 */
 780void drm_fb_helper_cfb_fillrect(struct fb_info *info,
 781				const struct fb_fillrect *rect)
 782{
 783	cfb_fillrect(info, rect);
 784	drm_fb_helper_dirty(info, rect->dx, rect->dy,
 785			    rect->width, rect->height);
 786}
 787EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect);
 788
 789/**
 790 * drm_fb_helper_cfb_copyarea - wrapper around cfb_copyarea
 791 * @info: fbdev registered by the helper
 792 * @area: info about area to copy
 793 *
 794 * A wrapper around cfb_copyarea implemented by fbdev core
 795 */
 796void drm_fb_helper_cfb_copyarea(struct fb_info *info,
 797				const struct fb_copyarea *area)
 798{
 799	cfb_copyarea(info, area);
 800	drm_fb_helper_dirty(info, area->dx, area->dy,
 801			    area->width, area->height);
 802}
 803EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea);
 804
 805/**
 806 * drm_fb_helper_cfb_imageblit - wrapper around cfb_imageblit
 807 * @info: fbdev registered by the helper
 808 * @image: info about image to blit
 809 *
 810 * A wrapper around cfb_imageblit implemented by fbdev core
 811 */
 812void drm_fb_helper_cfb_imageblit(struct fb_info *info,
 813				 const struct fb_image *image)
 814{
 815	cfb_imageblit(info, image);
 816	drm_fb_helper_dirty(info, image->dx, image->dy,
 817			    image->width, image->height);
 818}
 819EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit);
 820
 821/**
 822 * drm_fb_helper_set_suspend - wrapper around fb_set_suspend
 823 * @fb_helper: driver-allocated fbdev helper, can be NULL
 824 * @suspend: whether to suspend or resume
 825 *
 826 * A wrapper around fb_set_suspend implemented by fbdev core.
 827 * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
 828 * the lock yourself
 829 */
 830void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, bool suspend)
 831{
 832	if (fb_helper && fb_helper->fbdev)
 833		fb_set_suspend(fb_helper->fbdev, suspend);
 834}
 835EXPORT_SYMBOL(drm_fb_helper_set_suspend);
 836
 837/**
 838 * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
 839 *                                      takes the console lock
 840 * @fb_helper: driver-allocated fbdev helper, can be NULL
 841 * @suspend: whether to suspend or resume
 842 *
 843 * A wrapper around fb_set_suspend() that takes the console lock. If the lock
 844 * isn't available on resume, a worker is tasked with waiting for the lock
 845 * to become available. The console lock can be pretty contented on resume
 846 * due to all the printk activity.
 847 *
 848 * This function can be called multiple times with the same state since
 849 * &fb_info.state is checked to see if fbdev is running or not before locking.
 850 *
 851 * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
 852 */
 853void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
 854					bool suspend)
 855{
 856	if (!fb_helper || !fb_helper->fbdev)
 857		return;
 858
 859	/* make sure there's no pending/ongoing resume */
 860	flush_work(&fb_helper->resume_work);
 861
 862	if (suspend) {
 863		if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
 864			return;
 865
 866		console_lock();
 867
 868	} else {
 869		if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
 870			return;
 871
 872		if (!console_trylock()) {
 873			schedule_work(&fb_helper->resume_work);
 874			return;
 875		}
 876	}
 877
 878	fb_set_suspend(fb_helper->fbdev, suspend);
 879	console_unlock();
 880}
 881EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
 882
 883static int setcmap_pseudo_palette(struct fb_cmap *cmap, struct fb_info *info)
 884{
 885	u32 *palette = (u32 *)info->pseudo_palette;
 886	int i;
 887
 888	if (cmap->start + cmap->len > 16)
 889		return -EINVAL;
 890
 891	for (i = 0; i < cmap->len; ++i) {
 892		u16 red = cmap->red[i];
 893		u16 green = cmap->green[i];
 894		u16 blue = cmap->blue[i];
 895		u32 value;
 896
 897		red >>= 16 - info->var.red.length;
 898		green >>= 16 - info->var.green.length;
 899		blue >>= 16 - info->var.blue.length;
 900		value = (red << info->var.red.offset) |
 901			(green << info->var.green.offset) |
 902			(blue << info->var.blue.offset);
 903		if (info->var.transp.length > 0) {
 904			u32 mask = (1 << info->var.transp.length) - 1;
 905
 906			mask <<= info->var.transp.offset;
 907			value |= mask;
 908		}
 909		palette[cmap->start + i] = value;
 910	}
 911
 912	return 0;
 913}
 914
 915static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info)
 916{
 917	struct drm_fb_helper *fb_helper = info->par;
 918	struct drm_mode_set *modeset;
 919	struct drm_crtc *crtc;
 920	u16 *r, *g, *b;
 921	int ret = 0;
 922
 923	drm_modeset_lock_all(fb_helper->dev);
 924	drm_client_for_each_modeset(modeset, &fb_helper->client) {
 925		crtc = modeset->crtc;
 926		if (!crtc->funcs->gamma_set || !crtc->gamma_size)
 927			return -EINVAL;
 
 
 928
 929		if (cmap->start + cmap->len > crtc->gamma_size)
 930			return -EINVAL;
 
 
 931
 932		r = crtc->gamma_store;
 933		g = r + crtc->gamma_size;
 934		b = g + crtc->gamma_size;
 935
 936		memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
 937		memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
 938		memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
 939
 940		ret = crtc->funcs->gamma_set(crtc, r, g, b,
 941					     crtc->gamma_size, NULL);
 942		if (ret)
 943			return ret;
 944	}
 
 945	drm_modeset_unlock_all(fb_helper->dev);
 946
 947	return ret;
 948}
 949
 950static struct drm_property_blob *setcmap_new_gamma_lut(struct drm_crtc *crtc,
 951						       struct fb_cmap *cmap)
 952{
 953	struct drm_device *dev = crtc->dev;
 954	struct drm_property_blob *gamma_lut;
 955	struct drm_color_lut *lut;
 956	int size = crtc->gamma_size;
 957	int i;
 958
 959	if (!size || cmap->start + cmap->len > size)
 960		return ERR_PTR(-EINVAL);
 961
 962	gamma_lut = drm_property_create_blob(dev, sizeof(*lut) * size, NULL);
 963	if (IS_ERR(gamma_lut))
 964		return gamma_lut;
 965
 966	lut = gamma_lut->data;
 967	if (cmap->start || cmap->len != size) {
 968		u16 *r = crtc->gamma_store;
 969		u16 *g = r + crtc->gamma_size;
 970		u16 *b = g + crtc->gamma_size;
 971
 972		for (i = 0; i < cmap->start; i++) {
 973			lut[i].red = r[i];
 974			lut[i].green = g[i];
 975			lut[i].blue = b[i];
 976		}
 977		for (i = cmap->start + cmap->len; i < size; i++) {
 978			lut[i].red = r[i];
 979			lut[i].green = g[i];
 980			lut[i].blue = b[i];
 981		}
 982	}
 983
 984	for (i = 0; i < cmap->len; i++) {
 985		lut[cmap->start + i].red = cmap->red[i];
 986		lut[cmap->start + i].green = cmap->green[i];
 987		lut[cmap->start + i].blue = cmap->blue[i];
 988	}
 989
 990	return gamma_lut;
 991}
 992
 993static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
 994{
 995	struct drm_fb_helper *fb_helper = info->par;
 996	struct drm_device *dev = fb_helper->dev;
 997	struct drm_property_blob *gamma_lut = NULL;
 998	struct drm_modeset_acquire_ctx ctx;
 999	struct drm_crtc_state *crtc_state;
1000	struct drm_atomic_state *state;
1001	struct drm_mode_set *modeset;
1002	struct drm_crtc *crtc;
1003	u16 *r, *g, *b;
1004	bool replaced;
1005	int ret = 0;
1006
1007	drm_modeset_acquire_init(&ctx, 0);
1008
1009	state = drm_atomic_state_alloc(dev);
1010	if (!state) {
1011		ret = -ENOMEM;
1012		goto out_ctx;
1013	}
1014
1015	state->acquire_ctx = &ctx;
1016retry:
1017	drm_client_for_each_modeset(modeset, &fb_helper->client) {
1018		crtc = modeset->crtc;
1019
1020		if (!gamma_lut)
1021			gamma_lut = setcmap_new_gamma_lut(crtc, cmap);
1022		if (IS_ERR(gamma_lut)) {
1023			ret = PTR_ERR(gamma_lut);
1024			gamma_lut = NULL;
1025			goto out_state;
1026		}
1027
1028		crtc_state = drm_atomic_get_crtc_state(state, crtc);
1029		if (IS_ERR(crtc_state)) {
1030			ret = PTR_ERR(crtc_state);
1031			goto out_state;
1032		}
1033
 
 
 
 
 
1034		replaced  = drm_property_replace_blob(&crtc_state->degamma_lut,
1035						      NULL);
1036		replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
1037		replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
1038						      gamma_lut);
1039		crtc_state->color_mgmt_changed |= replaced;
1040	}
1041
1042	ret = drm_atomic_commit(state);
1043	if (ret)
1044		goto out_state;
1045
1046	drm_client_for_each_modeset(modeset, &fb_helper->client) {
1047		crtc = modeset->crtc;
1048
1049		r = crtc->gamma_store;
1050		g = r + crtc->gamma_size;
1051		b = g + crtc->gamma_size;
1052
1053		memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
1054		memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
1055		memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
1056	}
1057
1058out_state:
1059	if (ret == -EDEADLK)
1060		goto backoff;
1061
1062	drm_property_blob_put(gamma_lut);
1063	drm_atomic_state_put(state);
1064out_ctx:
1065	drm_modeset_drop_locks(&ctx);
1066	drm_modeset_acquire_fini(&ctx);
1067
1068	return ret;
1069
1070backoff:
1071	drm_atomic_state_clear(state);
1072	drm_modeset_backoff(&ctx);
1073	goto retry;
1074}
1075
1076/**
1077 * drm_fb_helper_setcmap - implementation for &fb_ops.fb_setcmap
1078 * @cmap: cmap to set
1079 * @info: fbdev registered by the helper
1080 */
1081int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
1082{
1083	struct drm_fb_helper *fb_helper = info->par;
1084	struct drm_device *dev = fb_helper->dev;
1085	int ret;
1086
1087	if (oops_in_progress)
1088		return -EBUSY;
1089
1090	mutex_lock(&fb_helper->lock);
1091
1092	if (!drm_master_internal_acquire(dev)) {
1093		ret = -EBUSY;
1094		goto unlock;
1095	}
1096
1097	mutex_lock(&fb_helper->client.modeset_mutex);
1098	if (info->fix.visual == FB_VISUAL_TRUECOLOR)
1099		ret = setcmap_pseudo_palette(cmap, info);
1100	else if (drm_drv_uses_atomic_modeset(fb_helper->dev))
1101		ret = setcmap_atomic(cmap, info);
1102	else
1103		ret = setcmap_legacy(cmap, info);
1104	mutex_unlock(&fb_helper->client.modeset_mutex);
1105
1106	drm_master_internal_release(dev);
1107unlock:
1108	mutex_unlock(&fb_helper->lock);
1109
1110	return ret;
1111}
1112EXPORT_SYMBOL(drm_fb_helper_setcmap);
1113
1114/**
1115 * drm_fb_helper_ioctl - legacy ioctl implementation
1116 * @info: fbdev registered by the helper
1117 * @cmd: ioctl command
1118 * @arg: ioctl argument
1119 *
1120 * A helper to implement the standard fbdev ioctl. Only
1121 * FBIO_WAITFORVSYNC is implemented for now.
1122 */
1123int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
1124			unsigned long arg)
1125{
1126	struct drm_fb_helper *fb_helper = info->par;
1127	struct drm_device *dev = fb_helper->dev;
1128	struct drm_crtc *crtc;
1129	int ret = 0;
1130
1131	mutex_lock(&fb_helper->lock);
1132	if (!drm_master_internal_acquire(dev)) {
1133		ret = -EBUSY;
1134		goto unlock;
1135	}
1136
1137	switch (cmd) {
1138	case FBIO_WAITFORVSYNC:
1139		/*
1140		 * Only consider the first CRTC.
1141		 *
1142		 * This ioctl is supposed to take the CRTC number as
1143		 * an argument, but in fbdev times, what that number
1144		 * was supposed to be was quite unclear, different
1145		 * drivers were passing that argument differently
1146		 * (some by reference, some by value), and most of the
1147		 * userspace applications were just hardcoding 0 as an
1148		 * argument.
1149		 *
1150		 * The first CRTC should be the integrated panel on
1151		 * most drivers, so this is the best choice we can
1152		 * make. If we're not smart enough here, one should
1153		 * just consider switch the userspace to KMS.
1154		 */
1155		crtc = fb_helper->client.modesets[0].crtc;
1156
1157		/*
1158		 * Only wait for a vblank event if the CRTC is
1159		 * enabled, otherwise just don't do anythintg,
1160		 * not even report an error.
1161		 */
1162		ret = drm_crtc_vblank_get(crtc);
1163		if (!ret) {
1164			drm_crtc_wait_one_vblank(crtc);
1165			drm_crtc_vblank_put(crtc);
1166		}
1167
1168		ret = 0;
1169		break;
1170	default:
1171		ret = -ENOTTY;
1172	}
1173
1174	drm_master_internal_release(dev);
1175unlock:
1176	mutex_unlock(&fb_helper->lock);
1177	return ret;
1178}
1179EXPORT_SYMBOL(drm_fb_helper_ioctl);
1180
1181static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1,
1182				      const struct fb_var_screeninfo *var_2)
1183{
1184	return var_1->bits_per_pixel == var_2->bits_per_pixel &&
1185	       var_1->grayscale == var_2->grayscale &&
1186	       var_1->red.offset == var_2->red.offset &&
1187	       var_1->red.length == var_2->red.length &&
1188	       var_1->red.msb_right == var_2->red.msb_right &&
1189	       var_1->green.offset == var_2->green.offset &&
1190	       var_1->green.length == var_2->green.length &&
1191	       var_1->green.msb_right == var_2->green.msb_right &&
1192	       var_1->blue.offset == var_2->blue.offset &&
1193	       var_1->blue.length == var_2->blue.length &&
1194	       var_1->blue.msb_right == var_2->blue.msb_right &&
1195	       var_1->transp.offset == var_2->transp.offset &&
1196	       var_1->transp.length == var_2->transp.length &&
1197	       var_1->transp.msb_right == var_2->transp.msb_right;
1198}
1199
1200static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var,
1201					 u8 depth)
1202{
1203	switch (depth) {
1204	case 8:
1205		var->red.offset = 0;
1206		var->green.offset = 0;
1207		var->blue.offset = 0;
1208		var->red.length = 8; /* 8bit DAC */
1209		var->green.length = 8;
1210		var->blue.length = 8;
1211		var->transp.offset = 0;
1212		var->transp.length = 0;
1213		break;
1214	case 15:
1215		var->red.offset = 10;
1216		var->green.offset = 5;
1217		var->blue.offset = 0;
1218		var->red.length = 5;
1219		var->green.length = 5;
1220		var->blue.length = 5;
1221		var->transp.offset = 15;
1222		var->transp.length = 1;
1223		break;
1224	case 16:
1225		var->red.offset = 11;
1226		var->green.offset = 5;
1227		var->blue.offset = 0;
1228		var->red.length = 5;
1229		var->green.length = 6;
1230		var->blue.length = 5;
1231		var->transp.offset = 0;
1232		break;
1233	case 24:
1234		var->red.offset = 16;
1235		var->green.offset = 8;
1236		var->blue.offset = 0;
1237		var->red.length = 8;
1238		var->green.length = 8;
1239		var->blue.length = 8;
1240		var->transp.offset = 0;
1241		var->transp.length = 0;
1242		break;
1243	case 32:
1244		var->red.offset = 16;
1245		var->green.offset = 8;
1246		var->blue.offset = 0;
1247		var->red.length = 8;
1248		var->green.length = 8;
1249		var->blue.length = 8;
1250		var->transp.offset = 24;
1251		var->transp.length = 8;
1252		break;
1253	default:
1254		break;
1255	}
1256}
1257
1258/**
1259 * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var
1260 * @var: screeninfo to check
1261 * @info: fbdev registered by the helper
1262 */
1263int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
1264			    struct fb_info *info)
1265{
1266	struct drm_fb_helper *fb_helper = info->par;
1267	struct drm_framebuffer *fb = fb_helper->fb;
1268	struct drm_device *dev = fb_helper->dev;
1269
1270	if (in_dbg_master())
1271		return -EINVAL;
1272
1273	if (var->pixclock != 0) {
1274		drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel clock, value of pixclock is ignored\n");
1275		var->pixclock = 0;
1276	}
1277
1278	if ((drm_format_info_block_width(fb->format, 0) > 1) ||
1279	    (drm_format_info_block_height(fb->format, 0) > 1))
1280		return -EINVAL;
1281
1282	/*
1283	 * Changes struct fb_var_screeninfo are currently not pushed back
1284	 * to KMS, hence fail if different settings are requested.
1285	 */
1286	if (var->bits_per_pixel > fb->format->cpp[0] * 8 ||
1287	    var->xres > fb->width || var->yres > fb->height ||
1288	    var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
1289		drm_dbg_kms(dev, "fb requested width/height/bpp can't fit in current fb "
1290			  "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n",
1291			  var->xres, var->yres, var->bits_per_pixel,
1292			  var->xres_virtual, var->yres_virtual,
1293			  fb->width, fb->height, fb->format->cpp[0] * 8);
1294		return -EINVAL;
1295	}
1296
1297	/*
1298	 * Workaround for SDL 1.2, which is known to be setting all pixel format
1299	 * fields values to zero in some cases. We treat this situation as a
1300	 * kind of "use some reasonable autodetected values".
1301	 */
1302	if (!var->red.offset     && !var->green.offset    &&
1303	    !var->blue.offset    && !var->transp.offset   &&
1304	    !var->red.length     && !var->green.length    &&
1305	    !var->blue.length    && !var->transp.length   &&
1306	    !var->red.msb_right  && !var->green.msb_right &&
1307	    !var->blue.msb_right && !var->transp.msb_right) {
1308		drm_fb_helper_fill_pixel_fmt(var, fb->format->depth);
1309	}
1310
1311	/*
1312	 * Likewise, bits_per_pixel should be rounded up to a supported value.
1313	 */
1314	var->bits_per_pixel = fb->format->cpp[0] * 8;
1315
1316	/*
1317	 * drm fbdev emulation doesn't support changing the pixel format at all,
1318	 * so reject all pixel format changing requests.
1319	 */
1320	if (!drm_fb_pixel_format_equal(var, &info->var)) {
1321		drm_dbg_kms(dev, "fbdev emulation doesn't support changing the pixel format\n");
1322		return -EINVAL;
1323	}
1324
1325	return 0;
1326}
1327EXPORT_SYMBOL(drm_fb_helper_check_var);
1328
1329/**
1330 * drm_fb_helper_set_par - implementation for &fb_ops.fb_set_par
1331 * @info: fbdev registered by the helper
1332 *
1333 * This will let fbcon do the mode init and is called at initialization time by
1334 * the fbdev core when registering the driver, and later on through the hotplug
1335 * callback.
1336 */
1337int drm_fb_helper_set_par(struct fb_info *info)
1338{
1339	struct drm_fb_helper *fb_helper = info->par;
1340	struct fb_var_screeninfo *var = &info->var;
1341	bool force;
1342
1343	if (oops_in_progress)
1344		return -EBUSY;
1345
1346	if (var->pixclock != 0) {
1347		drm_err(fb_helper->dev, "PIXEL CLOCK SET\n");
1348		return -EINVAL;
1349	}
1350
1351	/*
1352	 * Normally we want to make sure that a kms master takes precedence over
1353	 * fbdev, to avoid fbdev flickering and occasionally stealing the
1354	 * display status. But Xorg first sets the vt back to text mode using
1355	 * the KDSET IOCTL with KD_TEXT, and only after that drops the master
1356	 * status when exiting.
1357	 *
1358	 * In the past this was caught by drm_fb_helper_lastclose(), but on
1359	 * modern systems where logind always keeps a drm fd open to orchestrate
1360	 * the vt switching, this doesn't work.
1361	 *
1362	 * To not break the userspace ABI we have this special case here, which
1363	 * is only used for the above case. Everything else uses the normal
1364	 * commit function, which ensures that we never steal the display from
1365	 * an active drm master.
1366	 */
1367	force = var->activate & FB_ACTIVATE_KD_TEXT;
1368
1369	__drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper, force);
1370
1371	return 0;
1372}
1373EXPORT_SYMBOL(drm_fb_helper_set_par);
1374
1375static void pan_set(struct drm_fb_helper *fb_helper, int x, int y)
1376{
1377	struct drm_mode_set *mode_set;
1378
1379	mutex_lock(&fb_helper->client.modeset_mutex);
1380	drm_client_for_each_modeset(mode_set, &fb_helper->client) {
1381		mode_set->x = x;
1382		mode_set->y = y;
1383	}
1384	mutex_unlock(&fb_helper->client.modeset_mutex);
1385}
1386
1387static int pan_display_atomic(struct fb_var_screeninfo *var,
1388			      struct fb_info *info)
1389{
1390	struct drm_fb_helper *fb_helper = info->par;
1391	int ret;
1392
1393	pan_set(fb_helper, var->xoffset, var->yoffset);
1394
1395	ret = drm_client_modeset_commit_locked(&fb_helper->client);
1396	if (!ret) {
1397		info->var.xoffset = var->xoffset;
1398		info->var.yoffset = var->yoffset;
1399	} else
1400		pan_set(fb_helper, info->var.xoffset, info->var.yoffset);
1401
1402	return ret;
1403}
1404
1405static int pan_display_legacy(struct fb_var_screeninfo *var,
1406			      struct fb_info *info)
1407{
1408	struct drm_fb_helper *fb_helper = info->par;
1409	struct drm_client_dev *client = &fb_helper->client;
1410	struct drm_mode_set *modeset;
1411	int ret = 0;
1412
1413	mutex_lock(&client->modeset_mutex);
1414	drm_modeset_lock_all(fb_helper->dev);
1415	drm_client_for_each_modeset(modeset, client) {
1416		modeset->x = var->xoffset;
1417		modeset->y = var->yoffset;
1418
1419		if (modeset->num_connectors) {
1420			ret = drm_mode_set_config_internal(modeset);
1421			if (!ret) {
1422				info->var.xoffset = var->xoffset;
1423				info->var.yoffset = var->yoffset;
1424			}
1425		}
1426	}
1427	drm_modeset_unlock_all(fb_helper->dev);
1428	mutex_unlock(&client->modeset_mutex);
1429
1430	return ret;
1431}
1432
1433/**
1434 * drm_fb_helper_pan_display - implementation for &fb_ops.fb_pan_display
1435 * @var: updated screen information
1436 * @info: fbdev registered by the helper
1437 */
1438int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
1439			      struct fb_info *info)
1440{
1441	struct drm_fb_helper *fb_helper = info->par;
1442	struct drm_device *dev = fb_helper->dev;
1443	int ret;
1444
1445	if (oops_in_progress)
1446		return -EBUSY;
1447
1448	mutex_lock(&fb_helper->lock);
1449	if (!drm_master_internal_acquire(dev)) {
1450		ret = -EBUSY;
1451		goto unlock;
1452	}
1453
1454	if (drm_drv_uses_atomic_modeset(dev))
1455		ret = pan_display_atomic(var, info);
1456	else
1457		ret = pan_display_legacy(var, info);
1458
1459	drm_master_internal_release(dev);
1460unlock:
1461	mutex_unlock(&fb_helper->lock);
1462
1463	return ret;
1464}
1465EXPORT_SYMBOL(drm_fb_helper_pan_display);
1466
1467/*
1468 * Allocates the backing storage and sets up the fbdev info structure through
1469 * the ->fb_probe callback.
1470 */
1471static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
1472					 int preferred_bpp)
1473{
1474	struct drm_client_dev *client = &fb_helper->client;
1475	struct drm_device *dev = fb_helper->dev;
 
1476	int ret = 0;
1477	int crtc_count = 0;
1478	struct drm_connector_list_iter conn_iter;
1479	struct drm_fb_helper_surface_size sizes;
1480	struct drm_connector *connector;
1481	struct drm_mode_set *mode_set;
1482	int best_depth = 0;
1483
1484	memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
1485	sizes.surface_depth = 24;
1486	sizes.surface_bpp = 32;
1487	sizes.fb_width = (u32)-1;
1488	sizes.fb_height = (u32)-1;
1489
1490	/*
1491	 * If driver picks 8 or 16 by default use that for both depth/bpp
1492	 * to begin with
1493	 */
1494	if (preferred_bpp != sizes.surface_bpp)
1495		sizes.surface_depth = sizes.surface_bpp = preferred_bpp;
1496
1497	drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1498	drm_client_for_each_connector_iter(connector, &conn_iter) {
1499		struct drm_cmdline_mode *cmdline_mode;
1500
1501		cmdline_mode = &connector->cmdline_mode;
1502
1503		if (cmdline_mode->bpp_specified) {
1504			switch (cmdline_mode->bpp) {
1505			case 8:
1506				sizes.surface_depth = sizes.surface_bpp = 8;
1507				break;
1508			case 15:
1509				sizes.surface_depth = 15;
1510				sizes.surface_bpp = 16;
1511				break;
1512			case 16:
1513				sizes.surface_depth = sizes.surface_bpp = 16;
1514				break;
1515			case 24:
1516				sizes.surface_depth = sizes.surface_bpp = 24;
1517				break;
1518			case 32:
1519				sizes.surface_depth = 24;
1520				sizes.surface_bpp = 32;
1521				break;
1522			}
1523			break;
1524		}
1525	}
1526	drm_connector_list_iter_end(&conn_iter);
1527
1528	/*
1529	 * If we run into a situation where, for example, the primary plane
1530	 * supports RGBA5551 (16 bpp, depth 15) but not RGB565 (16 bpp, depth
1531	 * 16) we need to scale down the depth of the sizes we request.
1532	 */
1533	mutex_lock(&client->modeset_mutex);
1534	drm_client_for_each_modeset(mode_set, client) {
1535		struct drm_crtc *crtc = mode_set->crtc;
1536		struct drm_plane *plane = crtc->primary;
1537		int j;
1538
1539		drm_dbg_kms(dev, "test CRTC %u primary plane\n", drm_crtc_index(crtc));
1540
1541		for (j = 0; j < plane->format_count; j++) {
1542			const struct drm_format_info *fmt;
1543
1544			fmt = drm_format_info(plane->format_types[j]);
1545
1546			/*
1547			 * Do not consider YUV or other complicated formats
1548			 * for framebuffers. This means only legacy formats
1549			 * are supported (fmt->depth is a legacy field) but
1550			 * the framebuffer emulation can only deal with such
1551			 * formats, specifically RGB/BGA formats.
1552			 */
1553			if (fmt->depth == 0)
1554				continue;
1555
1556			/* We found a perfect fit, great */
1557			if (fmt->depth == sizes.surface_depth) {
1558				best_depth = fmt->depth;
1559				break;
1560			}
1561
1562			/* Skip depths above what we're looking for */
1563			if (fmt->depth > sizes.surface_depth)
1564				continue;
1565
1566			/* Best depth found so far */
1567			if (fmt->depth > best_depth)
1568				best_depth = fmt->depth;
1569		}
1570	}
1571	if (sizes.surface_depth != best_depth && best_depth) {
1572		drm_info(dev, "requested bpp %d, scaled depth down to %d",
1573			 sizes.surface_bpp, best_depth);
1574		sizes.surface_depth = best_depth;
1575	}
1576
1577	/* first up get a count of crtcs now in use and new min/maxes width/heights */
1578	crtc_count = 0;
1579	drm_client_for_each_modeset(mode_set, client) {
1580		struct drm_display_mode *desired_mode;
1581		int x, y, j;
1582		/* in case of tile group, are we the last tile vert or horiz?
1583		 * If no tile group you are always the last one both vertically
1584		 * and horizontally
1585		 */
1586		bool lastv = true, lasth = true;
1587
1588		desired_mode = mode_set->mode;
1589
1590		if (!desired_mode)
1591			continue;
1592
1593		crtc_count++;
1594
1595		x = mode_set->x;
1596		y = mode_set->y;
1597
1598		sizes.surface_width  = max_t(u32, desired_mode->hdisplay + x, sizes.surface_width);
1599		sizes.surface_height = max_t(u32, desired_mode->vdisplay + y, sizes.surface_height);
1600
1601		for (j = 0; j < mode_set->num_connectors; j++) {
1602			struct drm_connector *connector = mode_set->connectors[j];
1603
1604			if (connector->has_tile &&
1605			    desired_mode->hdisplay == connector->tile_h_size &&
1606			    desired_mode->vdisplay == connector->tile_v_size) {
1607				lasth = (connector->tile_h_loc == (connector->num_h_tile - 1));
1608				lastv = (connector->tile_v_loc == (connector->num_v_tile - 1));
1609				/* cloning to multiple tiles is just crazy-talk, so: */
1610				break;
1611			}
1612		}
1613
1614		if (lasth)
1615			sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
1616		if (lastv)
1617			sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
1618	}
1619	mutex_unlock(&client->modeset_mutex);
1620
1621	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
1622		drm_info(dev, "Cannot find any crtc or sizes\n");
1623
1624		/* First time: disable all crtc's.. */
1625		if (!fb_helper->deferred_setup)
1626			drm_client_modeset_commit(client);
1627		return -EAGAIN;
1628	}
1629
1630	/* Handle our overallocation */
1631	sizes.surface_height *= drm_fbdev_overalloc;
1632	sizes.surface_height /= 100;
 
 
 
 
 
1633
1634	/* push down into drivers */
1635	ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
1636	if (ret < 0)
1637		return ret;
1638
1639	strcpy(fb_helper->fb->comm, "[fbcon]");
1640	return 0;
1641}
1642
1643static void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
1644				   uint32_t depth)
1645{
1646	info->fix.type = FB_TYPE_PACKED_PIXELS;
1647	info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
1648		FB_VISUAL_TRUECOLOR;
1649	info->fix.mmio_start = 0;
1650	info->fix.mmio_len = 0;
1651	info->fix.type_aux = 0;
1652	info->fix.xpanstep = 1; /* doing it in hw */
1653	info->fix.ypanstep = 1; /* doing it in hw */
1654	info->fix.ywrapstep = 0;
1655	info->fix.accel = FB_ACCEL_NONE;
1656
1657	info->fix.line_length = pitch;
1658}
1659
1660static void drm_fb_helper_fill_var(struct fb_info *info,
1661				   struct drm_fb_helper *fb_helper,
1662				   uint32_t fb_width, uint32_t fb_height)
1663{
1664	struct drm_framebuffer *fb = fb_helper->fb;
1665
1666	WARN_ON((drm_format_info_block_width(fb->format, 0) > 1) ||
1667		(drm_format_info_block_height(fb->format, 0) > 1));
1668	info->pseudo_palette = fb_helper->pseudo_palette;
1669	info->var.xres_virtual = fb->width;
1670	info->var.yres_virtual = fb->height;
1671	info->var.bits_per_pixel = fb->format->cpp[0] * 8;
1672	info->var.accel_flags = FB_ACCELF_TEXT;
1673	info->var.xoffset = 0;
1674	info->var.yoffset = 0;
1675	info->var.activate = FB_ACTIVATE_NOW;
1676
1677	drm_fb_helper_fill_pixel_fmt(&info->var, fb->format->depth);
1678
1679	info->var.xres = fb_width;
1680	info->var.yres = fb_height;
1681}
1682
1683/**
1684 * drm_fb_helper_fill_info - initializes fbdev information
1685 * @info: fbdev instance to set up
1686 * @fb_helper: fb helper instance to use as template
1687 * @sizes: describes fbdev size and scanout surface size
1688 *
1689 * Sets up the variable and fixed fbdev metainformation from the given fb helper
1690 * instance and the drm framebuffer allocated in &drm_fb_helper.fb.
1691 *
1692 * Drivers should call this (or their equivalent setup code) from their
1693 * &drm_fb_helper_funcs.fb_probe callback after having allocated the fbdev
1694 * backing storage framebuffer.
1695 */
1696void drm_fb_helper_fill_info(struct fb_info *info,
1697			     struct drm_fb_helper *fb_helper,
1698			     struct drm_fb_helper_surface_size *sizes)
1699{
1700	struct drm_framebuffer *fb = fb_helper->fb;
1701
1702	drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
1703	drm_fb_helper_fill_var(info, fb_helper,
1704			       sizes->fb_width, sizes->fb_height);
1705
1706	info->par = fb_helper;
1707	snprintf(info->fix.id, sizeof(info->fix.id), "%sdrmfb",
1708		 fb_helper->dev->driver->name);
1709
1710}
1711EXPORT_SYMBOL(drm_fb_helper_fill_info);
1712
1713/*
1714 * This is a continuation of drm_setup_crtcs() that sets up anything related
1715 * to the framebuffer. During initialization, drm_setup_crtcs() is called before
1716 * the framebuffer has been allocated (fb_helper->fb and fb_helper->fbdev).
1717 * So, any setup that touches those fields needs to be done here instead of in
1718 * drm_setup_crtcs().
1719 */
1720static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
1721{
1722	struct drm_client_dev *client = &fb_helper->client;
1723	struct drm_connector_list_iter conn_iter;
1724	struct fb_info *info = fb_helper->fbdev;
1725	unsigned int rotation, sw_rotations = 0;
1726	struct drm_connector *connector;
1727	struct drm_mode_set *modeset;
1728
1729	mutex_lock(&client->modeset_mutex);
1730	drm_client_for_each_modeset(modeset, client) {
1731		if (!modeset->num_connectors)
1732			continue;
1733
1734		modeset->fb = fb_helper->fb;
1735
1736		if (drm_client_rotation(modeset, &rotation))
1737			/* Rotating in hardware, fbcon should not rotate */
1738			sw_rotations |= DRM_MODE_ROTATE_0;
1739		else
1740			sw_rotations |= rotation;
1741	}
1742	mutex_unlock(&client->modeset_mutex);
1743
1744	drm_connector_list_iter_begin(fb_helper->dev, &conn_iter);
1745	drm_client_for_each_connector_iter(connector, &conn_iter) {
1746
1747		/* use first connected connector for the physical dimensions */
1748		if (connector->status == connector_status_connected) {
1749			info->var.width = connector->display_info.width_mm;
1750			info->var.height = connector->display_info.height_mm;
1751			break;
1752		}
1753	}
1754	drm_connector_list_iter_end(&conn_iter);
1755
1756	switch (sw_rotations) {
1757	case DRM_MODE_ROTATE_0:
1758		info->fbcon_rotate_hint = FB_ROTATE_UR;
1759		break;
1760	case DRM_MODE_ROTATE_90:
1761		info->fbcon_rotate_hint = FB_ROTATE_CCW;
1762		break;
1763	case DRM_MODE_ROTATE_180:
1764		info->fbcon_rotate_hint = FB_ROTATE_UD;
1765		break;
1766	case DRM_MODE_ROTATE_270:
1767		info->fbcon_rotate_hint = FB_ROTATE_CW;
1768		break;
1769	default:
1770		/*
1771		 * Multiple bits are set / multiple rotations requested
1772		 * fbcon cannot handle separate rotation settings per
1773		 * output, so fallback to unrotated.
1774		 */
1775		info->fbcon_rotate_hint = FB_ROTATE_UR;
1776	}
1777}
1778
1779/* Note: Drops fb_helper->lock before returning. */
1780static int
1781__drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
1782					  int bpp_sel)
1783{
1784	struct drm_device *dev = fb_helper->dev;
1785	struct fb_info *info;
1786	unsigned int width, height;
1787	int ret;
1788
1789	width = dev->mode_config.max_width;
1790	height = dev->mode_config.max_height;
1791
1792	drm_client_modeset_probe(&fb_helper->client, width, height);
1793	ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel);
1794	if (ret < 0) {
1795		if (ret == -EAGAIN) {
1796			fb_helper->preferred_bpp = bpp_sel;
1797			fb_helper->deferred_setup = true;
1798			ret = 0;
1799		}
1800		mutex_unlock(&fb_helper->lock);
1801
1802		return ret;
1803	}
1804	drm_setup_crtcs_fb(fb_helper);
1805
1806	fb_helper->deferred_setup = false;
1807
1808	info = fb_helper->fbdev;
1809	info->var.pixclock = 0;
1810	/* Shamelessly allow physical address leaking to userspace */
1811#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
1812	if (!drm_leak_fbdev_smem)
1813#endif
1814		/* don't leak any physical addresses to userspace */
1815		info->flags |= FBINFO_HIDE_SMEM_START;
1816
1817	/* Need to drop locks to avoid recursive deadlock in
1818	 * register_framebuffer. This is ok because the only thing left to do is
1819	 * register the fbdev emulation instance in kernel_fb_helper_list. */
1820	mutex_unlock(&fb_helper->lock);
1821
1822	ret = register_framebuffer(info);
1823	if (ret < 0)
1824		return ret;
1825
1826	drm_info(dev, "fb%d: %s frame buffer device\n",
1827		 info->node, info->fix.id);
1828
1829	mutex_lock(&kernel_fb_helper_lock);
1830	if (list_empty(&kernel_fb_helper_list))
1831		register_sysrq_key('v', &sysrq_drm_fb_helper_restore_op);
1832
1833	list_add(&fb_helper->kernel_fb_list, &kernel_fb_helper_list);
1834	mutex_unlock(&kernel_fb_helper_lock);
1835
1836	return 0;
1837}
1838
1839/**
1840 * drm_fb_helper_initial_config - setup a sane initial connector configuration
1841 * @fb_helper: fb_helper device struct
1842 * @bpp_sel: bpp value to use for the framebuffer configuration
1843 *
1844 * Scans the CRTCs and connectors and tries to put together an initial setup.
1845 * At the moment, this is a cloned configuration across all heads with
1846 * a new framebuffer object as the backing store.
1847 *
1848 * Note that this also registers the fbdev and so allows userspace to call into
1849 * the driver through the fbdev interfaces.
1850 *
1851 * This function will call down into the &drm_fb_helper_funcs.fb_probe callback
1852 * to let the driver allocate and initialize the fbdev info structure and the
1853 * drm framebuffer used to back the fbdev. drm_fb_helper_fill_info() is provided
1854 * as a helper to setup simple default values for the fbdev info structure.
1855 *
1856 * HANG DEBUGGING:
1857 *
1858 * When you have fbcon support built-in or already loaded, this function will do
1859 * a full modeset to setup the fbdev console. Due to locking misdesign in the
1860 * VT/fbdev subsystem that entire modeset sequence has to be done while holding
1861 * console_lock. Until console_unlock is called no dmesg lines will be sent out
1862 * to consoles, not even serial console. This means when your driver crashes,
1863 * you will see absolutely nothing else but a system stuck in this function,
1864 * with no further output. Any kind of printk() you place within your own driver
1865 * or in the drm core modeset code will also never show up.
1866 *
1867 * Standard debug practice is to run the fbcon setup without taking the
1868 * console_lock as a hack, to be able to see backtraces and crashes on the
1869 * serial line. This can be done by setting the fb.lockless_register_fb=1 kernel
1870 * cmdline option.
1871 *
1872 * The other option is to just disable fbdev emulation since very likely the
1873 * first modeset from userspace will crash in the same way, and is even easier
1874 * to debug. This can be done by setting the drm_kms_helper.fbdev_emulation=0
1875 * kernel cmdline option.
1876 *
1877 * RETURNS:
1878 * Zero if everything went ok, nonzero otherwise.
1879 */
1880int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel)
1881{
1882	int ret;
1883
1884	if (!drm_fbdev_emulation)
1885		return 0;
1886
1887	mutex_lock(&fb_helper->lock);
1888	ret = __drm_fb_helper_initial_config_and_unlock(fb_helper, bpp_sel);
1889
1890	return ret;
1891}
1892EXPORT_SYMBOL(drm_fb_helper_initial_config);
1893
1894/**
1895 * drm_fb_helper_hotplug_event - respond to a hotplug notification by
1896 *                               probing all the outputs attached to the fb
1897 * @fb_helper: driver-allocated fbdev helper, can be NULL
1898 *
1899 * Scan the connectors attached to the fb_helper and try to put together a
1900 * setup after notification of a change in output configuration.
1901 *
1902 * Called at runtime, takes the mode config locks to be able to check/change the
1903 * modeset configuration. Must be run from process context (which usually means
1904 * either the output polling work or a work item launched from the driver's
1905 * hotplug interrupt).
1906 *
1907 * Note that drivers may call this even before calling
1908 * drm_fb_helper_initial_config but only after drm_fb_helper_init. This allows
1909 * for a race-free fbcon setup and will make sure that the fbdev emulation will
1910 * not miss any hotplug events.
1911 *
1912 * RETURNS:
1913 * 0 on success and a non-zero error code otherwise.
1914 */
1915int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
1916{
1917	int err = 0;
1918
1919	if (!drm_fbdev_emulation || !fb_helper)
1920		return 0;
1921
1922	mutex_lock(&fb_helper->lock);
1923	if (fb_helper->deferred_setup) {
1924		err = __drm_fb_helper_initial_config_and_unlock(fb_helper,
1925				fb_helper->preferred_bpp);
1926		return err;
1927	}
1928
1929	if (!fb_helper->fb || !drm_master_internal_acquire(fb_helper->dev)) {
1930		fb_helper->delayed_hotplug = true;
1931		mutex_unlock(&fb_helper->lock);
1932		return err;
1933	}
1934
1935	drm_master_internal_release(fb_helper->dev);
1936
1937	drm_dbg_kms(fb_helper->dev, "\n");
1938
1939	drm_client_modeset_probe(&fb_helper->client, fb_helper->fb->width, fb_helper->fb->height);
1940	drm_setup_crtcs_fb(fb_helper);
1941	mutex_unlock(&fb_helper->lock);
1942
1943	drm_fb_helper_set_par(fb_helper->fbdev);
1944
1945	return 0;
1946}
1947EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
1948
1949/**
1950 * drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
1951 * @dev: DRM device
1952 *
1953 * This function can be used as the &drm_driver->lastclose callback for drivers
1954 * that only need to call drm_fb_helper_restore_fbdev_mode_unlocked().
1955 */
1956void drm_fb_helper_lastclose(struct drm_device *dev)
1957{
1958	drm_fb_helper_restore_fbdev_mode_unlocked(dev->fb_helper);
1959}
1960EXPORT_SYMBOL(drm_fb_helper_lastclose);
1961
1962/**
1963 * drm_fb_helper_output_poll_changed - DRM mode config \.output_poll_changed
1964 *                                     helper for fbdev emulation
1965 * @dev: DRM device
1966 *
1967 * This function can be used as the
1968 * &drm_mode_config_funcs.output_poll_changed callback for drivers that only
1969 * need to call drm_fb_helper_hotplug_event().
1970 */
1971void drm_fb_helper_output_poll_changed(struct drm_device *dev)
1972{
1973	drm_fb_helper_hotplug_event(dev->fb_helper);
1974}
1975EXPORT_SYMBOL(drm_fb_helper_output_poll_changed);
1976
1977/* @user: 1=userspace, 0=fbcon */
1978static int drm_fbdev_fb_open(struct fb_info *info, int user)
1979{
1980	struct drm_fb_helper *fb_helper = info->par;
1981
1982	/* No need to take a ref for fbcon because it unbinds on unregister */
1983	if (user && !try_module_get(fb_helper->dev->driver->fops->owner))
1984		return -ENODEV;
1985
1986	return 0;
1987}
1988
1989static int drm_fbdev_fb_release(struct fb_info *info, int user)
1990{
1991	struct drm_fb_helper *fb_helper = info->par;
1992
1993	if (user)
1994		module_put(fb_helper->dev->driver->fops->owner);
1995
1996	return 0;
1997}
1998
1999static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
2000{
2001	struct fb_info *fbi = fb_helper->fbdev;
2002	void *shadow = NULL;
2003
2004	if (!fb_helper->dev)
2005		return;
2006
2007	if (fbi && fbi->fbdefio) {
2008		fb_deferred_io_cleanup(fbi);
2009		shadow = fbi->screen_buffer;
 
 
2010	}
2011
2012	drm_fb_helper_fini(fb_helper);
2013
2014	vfree(shadow);
 
 
 
2015
2016	drm_client_framebuffer_delete(fb_helper->buffer);
2017}
2018
2019static void drm_fbdev_release(struct drm_fb_helper *fb_helper)
2020{
2021	drm_fbdev_cleanup(fb_helper);
2022	drm_client_release(&fb_helper->client);
2023	kfree(fb_helper);
2024}
2025
2026/*
2027 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end of
2028 * unregister_framebuffer() or fb_release().
2029 */
2030static void drm_fbdev_fb_destroy(struct fb_info *info)
2031{
2032	drm_fbdev_release(info->par);
2033}
2034
2035static int drm_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
2036{
2037	struct drm_fb_helper *fb_helper = info->par;
2038
2039	if (fb_helper->dev->driver->gem_prime_mmap)
2040		return fb_helper->dev->driver->gem_prime_mmap(fb_helper->buffer->gem, vma);
2041	else
2042		return -ENODEV;
2043}
2044
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2045static const struct fb_ops drm_fbdev_fb_ops = {
2046	.owner		= THIS_MODULE,
2047	DRM_FB_HELPER_DEFAULT_OPS,
2048	.fb_open	= drm_fbdev_fb_open,
2049	.fb_release	= drm_fbdev_fb_release,
2050	.fb_destroy	= drm_fbdev_fb_destroy,
2051	.fb_mmap	= drm_fbdev_fb_mmap,
2052	.fb_read	= drm_fb_helper_sys_read,
2053	.fb_write	= drm_fb_helper_sys_write,
2054	.fb_fillrect	= drm_fb_helper_sys_fillrect,
2055	.fb_copyarea	= drm_fb_helper_sys_copyarea,
2056	.fb_imageblit	= drm_fb_helper_sys_imageblit,
2057};
2058
2059static struct fb_deferred_io drm_fbdev_defio = {
2060	.delay		= HZ / 20,
2061	.deferred_io	= drm_fb_helper_deferred_io,
2062};
2063
2064/*
2065 * This function uses the client API to create a framebuffer backed by a dumb buffer.
2066 *
2067 * The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
2068 * fb_copyarea, fb_imageblit.
2069 */
2070static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
2071				       struct drm_fb_helper_surface_size *sizes)
2072{
2073	struct drm_client_dev *client = &fb_helper->client;
2074	struct drm_device *dev = fb_helper->dev;
2075	struct drm_client_buffer *buffer;
2076	struct drm_framebuffer *fb;
2077	struct fb_info *fbi;
2078	u32 format;
2079	void *vaddr;
 
2080
2081	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
2082		    sizes->surface_width, sizes->surface_height,
2083		    sizes->surface_bpp);
2084
2085	format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
2086	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
2087					       sizes->surface_height, format);
2088	if (IS_ERR(buffer))
2089		return PTR_ERR(buffer);
2090
2091	fb_helper->buffer = buffer;
2092	fb_helper->fb = buffer->fb;
2093	fb = buffer->fb;
2094
2095	fbi = drm_fb_helper_alloc_fbi(fb_helper);
2096	if (IS_ERR(fbi))
2097		return PTR_ERR(fbi);
2098
2099	fbi->fbops = &drm_fbdev_fb_ops;
2100	fbi->screen_size = fb->height * fb->pitches[0];
2101	fbi->fix.smem_len = fbi->screen_size;
2102
2103	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
2104
2105	if (drm_fbdev_use_shadow_fb(fb_helper)) {
2106		fbi->screen_buffer = vzalloc(fbi->screen_size);
2107		if (!fbi->screen_buffer)
2108			return -ENOMEM;
2109
2110		fbi->fbdefio = &drm_fbdev_defio;
2111
2112		fb_deferred_io_init(fbi);
2113	} else {
2114		/* buffer is mapped for HW framebuffer */
2115		vaddr = drm_client_buffer_vmap(fb_helper->buffer);
2116		if (IS_ERR(vaddr))
2117			return PTR_ERR(vaddr);
 
 
 
 
2118
2119		fbi->screen_buffer = vaddr;
2120		/* Shamelessly leak the physical address to user-space */
 
 
 
2121#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
2122		if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
 
2123			fbi->fix.smem_start =
2124				page_to_phys(virt_to_page(fbi->screen_buffer));
2125#endif
2126	}
2127
2128	return 0;
2129}
2130
2131static const struct drm_fb_helper_funcs drm_fb_helper_generic_funcs = {
2132	.fb_probe = drm_fb_helper_generic_probe,
2133};
2134
2135static void drm_fbdev_client_unregister(struct drm_client_dev *client)
2136{
2137	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2138
2139	if (fb_helper->fbdev)
2140		/* drm_fbdev_fb_destroy() takes care of cleanup */
2141		drm_fb_helper_unregister_fbi(fb_helper);
2142	else
2143		drm_fbdev_release(fb_helper);
2144}
2145
2146static int drm_fbdev_client_restore(struct drm_client_dev *client)
2147{
2148	drm_fb_helper_lastclose(client->dev);
2149
2150	return 0;
2151}
2152
2153static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
2154{
2155	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
2156	struct drm_device *dev = client->dev;
2157	int ret;
2158
2159	/* Setup is not retried if it has failed */
2160	if (!fb_helper->dev && fb_helper->funcs)
2161		return 0;
2162
2163	if (dev->fb_helper)
2164		return drm_fb_helper_hotplug_event(dev->fb_helper);
2165
2166	if (!dev->mode_config.num_connector) {
2167		drm_dbg_kms(dev, "No connectors found, will not create framebuffer!\n");
2168		return 0;
2169	}
2170
2171	drm_fb_helper_prepare(dev, fb_helper, &drm_fb_helper_generic_funcs);
2172
2173	ret = drm_fb_helper_init(dev, fb_helper);
2174	if (ret)
2175		goto err;
2176
2177	if (!drm_drv_uses_atomic_modeset(dev))
2178		drm_helper_disable_unused_functions(dev);
2179
2180	ret = drm_fb_helper_initial_config(fb_helper, fb_helper->preferred_bpp);
2181	if (ret)
2182		goto err_cleanup;
2183
2184	return 0;
2185
2186err_cleanup:
2187	drm_fbdev_cleanup(fb_helper);
2188err:
2189	fb_helper->dev = NULL;
2190	fb_helper->fbdev = NULL;
2191
2192	drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);
2193
2194	return ret;
2195}
2196
2197static const struct drm_client_funcs drm_fbdev_client_funcs = {
2198	.owner		= THIS_MODULE,
2199	.unregister	= drm_fbdev_client_unregister,
2200	.restore	= drm_fbdev_client_restore,
2201	.hotplug	= drm_fbdev_client_hotplug,
2202};
2203
2204/**
2205 * drm_fbdev_generic_setup() - Setup generic fbdev emulation
2206 * @dev: DRM device
2207 * @preferred_bpp: Preferred bits per pixel for the device.
2208 *                 @dev->mode_config.preferred_depth is used if this is zero.
2209 *
2210 * This function sets up generic fbdev emulation for drivers that supports
2211 * dumb buffers with a virtual address and that can be mmap'ed.
2212 * drm_fbdev_generic_setup() shall be called after the DRM driver registered
2213 * the new DRM device with drm_dev_register().
2214 *
2215 * Restore, hotplug events and teardown are all taken care of. Drivers that do
2216 * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
2217 * Simple drivers might use drm_mode_config_helper_suspend().
2218 *
2219 * Drivers that set the dirty callback on their framebuffer will get a shadow
2220 * fbdev buffer that is blitted onto the real buffer. This is done in order to
2221 * make deferred I/O work with all kinds of buffers. A shadow buffer can be
2222 * requested explicitly by setting struct drm_mode_config.prefer_shadow or
2223 * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is
2224 * required to use generic fbdev emulation with SHMEM helpers.
2225 *
2226 * This function is safe to call even when there are no connectors present.
2227 * Setup will be retried on the next hotplug event.
2228 *
2229 * The fbdev is destroyed by drm_dev_unregister().
2230 */
2231void drm_fbdev_generic_setup(struct drm_device *dev,
2232			     unsigned int preferred_bpp)
2233{
2234	struct drm_fb_helper *fb_helper;
2235	int ret;
2236
2237	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");
2238	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n");
2239
2240	if (!drm_fbdev_emulation)
2241		return;
2242
2243	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
2244	if (!fb_helper) {
2245		drm_err(dev, "Failed to allocate fb_helper\n");
2246		return;
2247	}
2248
2249	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
2250	if (ret) {
2251		kfree(fb_helper);
2252		drm_err(dev, "Failed to register client: %d\n", ret);
2253		return;
2254	}
2255
 
 
 
 
 
2256	if (!preferred_bpp)
2257		preferred_bpp = dev->mode_config.preferred_depth;
2258	if (!preferred_bpp)
2259		preferred_bpp = 32;
2260	fb_helper->preferred_bpp = preferred_bpp;
2261
2262	ret = drm_fbdev_client_hotplug(&fb_helper->client);
2263	if (ret)
2264		drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
2265
2266	drm_client_register(&fb_helper->client);
2267}
2268EXPORT_SYMBOL(drm_fbdev_generic_setup);
2269
2270/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
2271 * but the module doesn't depend on any fb console symbols.  At least
2272 * attempt to load fbcon to avoid leaving the system without a usable console.
2273 */
2274int __init drm_fb_helper_modinit(void)
2275{
2276#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
2277	const char name[] = "fbcon";
2278	struct module *fbcon;
2279
2280	mutex_lock(&module_mutex);
2281	fbcon = find_module(name);
2282	mutex_unlock(&module_mutex);
2283
2284	if (!fbcon)
2285		request_module_nowait(name);
2286#endif
2287	return 0;
2288}
2289EXPORT_SYMBOL(drm_fb_helper_modinit);