/*
 * Copyright © 2007 David Airlie
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *     David Airlie
 */

#include <linux/async.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/console.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/vga_switcheroo.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include "intel_drv.h"
#include "intel_frontbuffer.h"
#include <drm/i915_drm.h>
#include "i915_drv.h"

static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
{
        struct drm_i915_gem_object *obj = intel_fb_obj(&ifbdev->fb->base);
        unsigned int origin =
                ifbdev->vma_flags & PLANE_HAS_FENCE ? ORIGIN_GTT : ORIGIN_CPU;

        intel_fb_obj_invalidate(obj, origin);
}

static int intel_fbdev_set_par(struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct intel_fbdev *ifbdev =
                container_of(fb_helper, struct intel_fbdev, helper);
        int ret;

        ret = drm_fb_helper_set_par(info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}

static int intel_fbdev_blank(int blank, struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct intel_fbdev *ifbdev =
                container_of(fb_helper, struct intel_fbdev, helper);
        int ret;

        ret = drm_fb_helper_blank(blank, info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}

#if 0
static int intel_fbdev_pan_display(struct fb_var_screeninfo *var,
                                   struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct intel_fbdev *ifbdev =
                container_of(fb_helper, struct intel_fbdev, helper);
        int ret;

        ret = drm_fb_helper_pan_display(var, info);
        if (ret == 0)
                intel_fbdev_invalidate(ifbdev);

        return ret;
}
#endif

static struct fb_ops intelfb_ops = {
#if 0
        .owner = THIS_MODULE,
#endif
        DRM_FB_HELPER_DEFAULT_OPS,
        .fb_set_par = intel_fbdev_set_par,
#if 0
        .fb_fillrect = drm_fb_helper_cfb_fillrect,
        .fb_copyarea = drm_fb_helper_cfb_copyarea,
        .fb_imageblit = drm_fb_helper_cfb_imageblit,
        .fb_pan_display = intel_fbdev_pan_display,
#endif
        .fb_blank = intel_fbdev_blank,
};

static int intelfb_alloc(struct drm_fb_helper *helper,
                         struct drm_fb_helper_surface_size *sizes)
{
        struct intel_fbdev *ifbdev =
                container_of(helper, struct intel_fbdev, helper);
        struct drm_framebuffer *fb;
        struct drm_device *dev = helper->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct drm_mode_fb_cmd2 mode_cmd = {};
        struct drm_i915_gem_object *obj;
        int size, ret;

        /* we don't do packed 24bpp */
        if (sizes->surface_bpp == 24)
                sizes->surface_bpp = 32;

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;

        mode_cmd.pitches[0] = ALIGN(mode_cmd.width *
                                    DIV_ROUND_UP(sizes->surface_bpp, 8), 64);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                          sizes->surface_depth);

        size = mode_cmd.pitches[0] * mode_cmd.height;
        size = PAGE_ALIGN(size);

        /* If the FB is too big, just don't use it since fbdev is not very
         * important and we should probably use that space with FBC or other
         * features. */
        obj = NULL;
        if (size * 2 < dev_priv->stolen_usable_size)
                obj = i915_gem_object_create_stolen(dev_priv, size);
        if (obj == NULL)
                obj = i915_gem_object_create(dev_priv, size);
        if (IS_ERR(obj)) {
                DRM_ERROR("failed to allocate framebuffer\n");
                ret = PTR_ERR(obj);
                goto err;
        }

        fb = intel_framebuffer_create(obj, &mode_cmd);
        if (IS_ERR(fb)) {
                ret = PTR_ERR(fb);
                goto err_obj;
        }

        ifbdev->fb = to_intel_framebuffer(fb);

        return 0;

err_obj:
        i915_gem_object_put(obj);
err:
        return ret;
}

static int intelfb_create(struct drm_fb_helper *helper,
                          struct drm_fb_helper_surface_size *sizes)
{
        struct intel_fbdev *ifbdev =
                container_of(helper, struct intel_fbdev, helper);
        struct intel_framebuffer *intel_fb = ifbdev->fb;
        struct drm_device *dev = helper->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct pci_dev *pdev = dev_priv->drm.pdev;
        struct i915_ggtt *ggtt = &dev_priv->ggtt;
        const struct i915_ggtt_view view = {
                .type = I915_GGTT_VIEW_NORMAL,
        };
        struct fb_info *info;
        struct drm_framebuffer *fb;
        struct i915_vma *vma;
        unsigned long flags = 0;
        bool prealloc = false;
        void __iomem *vaddr;
        int ret;
        device_t vga_dev;

        if (intel_fb &&
            (sizes->fb_width > intel_fb->base.width ||
             sizes->fb_height > intel_fb->base.height)) {
                DRM_DEBUG_KMS("BIOS fb too small (%dx%d), we require (%dx%d),"
                              " releasing it\n",
                              intel_fb->base.width, intel_fb->base.height,
                              sizes->fb_width, sizes->fb_height);
                drm_framebuffer_put(&intel_fb->base);
                intel_fb = ifbdev->fb = NULL;
        }
        if (!intel_fb || WARN_ON(!intel_fb_obj(&intel_fb->base))) {
                DRM_DEBUG_KMS("no BIOS fb, allocating a new one\n");
                ret = intelfb_alloc(helper, sizes);
                if (ret)
                        return ret;
                intel_fb = ifbdev->fb;
        } else {
                DRM_DEBUG_KMS("re-using BIOS fb\n");
                prealloc = true;
                sizes->fb_width = intel_fb->base.width;
                sizes->fb_height = intel_fb->base.height;
        }

        mutex_lock(&dev->struct_mutex);
        intel_runtime_pm_get(dev_priv);

        /* Pin the GGTT vma for our access via info->screen_base.
         * This also validates that any existing fb inherited from the
         * BIOS is suitable for own access.
         */
        vma = intel_pin_and_fence_fb_obj(&ifbdev->fb->base,
                                         &view, false, &flags);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
                goto out_unlock;
        }

        fb = &ifbdev->fb->base;
        intel_fb_obj_flush(intel_fb_obj(fb), ORIGIN_DIRTYFB);

        info = drm_fb_helper_alloc_fbi(helper);
        if (IS_ERR(info)) {
                DRM_ERROR("Failed to allocate fb_info\n");
                ret = PTR_ERR(info);
                goto out_unpin;
        }

        info->par = helper;

        ifbdev->helper.fb = fb;

#ifdef __DragonFly__
        vga_dev = device_get_parent(dev->dev->bsddev);
        info->width = sizes->fb_width;
        info->height = sizes->fb_height;
        info->stride = fb->pitches[0];
        info->depth = sizes->surface_bpp;
        info->paddr = ggtt->gmadr.start + vma->node.start;
        info->is_vga_boot_display = vga_pci_is_boot_display(vga_dev);
        info->fbops = intelfb_ops;

#else
        strcpy(info->fix.id, "inteldrmfb");

        info->fbops = &intelfb_ops;

        /* setup aperture base/size for vesafb takeover */
        info->apertures->ranges[0].base = dev->mode_config.fb_base;
        info->apertures->ranges[0].size = ggtt->mappable_end;

        info->fix.smem_start = dev->mode_config.fb_base + i915_ggtt_offset(vma);
        info->fix.smem_len = vma->node.size;
#endif

        vaddr = i915_vma_pin_iomap(vma);
        if (IS_ERR(vaddr)) {
                DRM_ERROR("Failed to remap framebuffer into virtual memory\n");
                ret = PTR_ERR(vaddr);
                goto out_unpin;
        }
#ifdef __DragonFly__
        info->vaddr = (vm_offset_t)vaddr;
#else
        info->screen_base = vaddr;
        info->screen_size = vma->node.size;

        /* This driver doesn't need a VT switch to restore the mode on resume */
        info->skip_vt_switch = true;

        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
        drm_fb_helper_fill_var(info, &ifbdev->helper, sizes->fb_width, sizes->fb_height);

        /* If the object is shmemfs backed, it will have given us zeroed pages.
         * If the object is stolen however, it will be full of whatever
         * garbage was left in there.
         */
        if (intel_fb_obj(fb)->stolen && !prealloc)
                memset_io(info->screen_base, 0, info->screen_size);
#endif

        /* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */

        DRM_DEBUG_KMS("allocated %dx%d fb: 0x%08x\n",
                      fb->width, fb->height, i915_ggtt_offset(vma));
        ifbdev->vma = vma;
        ifbdev->vma_flags = flags;

        intel_runtime_pm_put(dev_priv);
        mutex_unlock(&dev->struct_mutex);
        vga_switcheroo_client_fb_set(pdev, info);
        return 0;

out_unpin:
        intel_unpin_fb_vma(vma, flags);
out_unlock:
        intel_runtime_pm_put(dev_priv);
        mutex_unlock(&dev->struct_mutex);
        return ret;
}

static struct drm_fb_helper_crtc *
intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
{
        int i;

        for (i = 0; i < fb_helper->crtc_count; i++)
                if (fb_helper->crtc_info[i].mode_set.crtc == crtc)
                        return &fb_helper->crtc_info[i];

        return NULL;
}

/*
 * Try to read the BIOS display configuration and use it for the initial
 * fb configuration.
 *
 * The BIOS or boot loader will generally create an initial display
 * configuration for us that includes some set of active pipes and displays.
 * This routine tries to figure out which pipes and connectors are active
 * and stuffs them into the crtcs and modes array given to us by the
 * drm_fb_helper code.
 *
 * The overall sequence is:
 *   intel_fbdev_init - from driver load
 *     intel_fbdev_init_bios - initialize the intel_fbdev using BIOS data
 *     drm_fb_helper_init - build fb helper structs
 *     drm_fb_helper_single_add_all_connectors - more fb helper structs
 *   intel_fbdev_initial_config - apply the config
 *     drm_fb_helper_initial_config - call ->probe then register_framebuffer()
 *         drm_setup_crtcs - build crtc config for fbdev
 *           intel_fb_initial_config - find active connectors etc
 *         drm_fb_helper_single_fb_probe - set up fbdev
 *           intelfb_create - re-use or alloc fb, build out fbdev structs
 *
 * Note that we don't make special consideration whether we could actually
 * switch to the selected modes without a full modeset. E.g. when the display
 * is in VGA mode we need to recalculate watermarks and set a new high-res
 * framebuffer anyway.
 */
static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
                                    struct drm_fb_helper_crtc **crtcs,
                                    struct drm_display_mode **modes,
                                    struct drm_fb_offset *offsets,
                                    bool *enabled, int width, int height)
{
        struct drm_i915_private *dev_priv = to_i915(fb_helper->dev);
        unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG);
        unsigned long conn_configured, conn_seq;
        int i, j;
        bool *save_enabled;
        bool fallback = true, ret = true;
        int num_connectors_enabled = 0;
        int num_connectors_detected = 0;
        struct drm_modeset_acquire_ctx ctx;

        save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL);
        if (!save_enabled)
                return false;

        drm_modeset_acquire_init(&ctx, 0);

        while (drm_modeset_lock_all_ctx(fb_helper->dev, &ctx) != 0)
                drm_modeset_backoff(&ctx);

        memcpy(save_enabled, enabled, count);
        conn_seq = GENMASK(count - 1, 0);
        conn_configured = 0;
retry:
        for (i = 0; i < count; i++) {
                struct drm_fb_helper_connector *fb_conn;
                struct drm_connector *connector;
                struct drm_encoder *encoder;
                struct drm_fb_helper_crtc *new_crtc;

                fb_conn = fb_helper->connector_info[i];
                connector = fb_conn->connector;

                if (conn_configured & BIT(i))
                        continue;

                /* First pass, only consider tiled connectors */
                if (conn_seq == GENMASK(count - 1, 0) && !connector->has_tile)
                        continue;

                if (connector->status == connector_status_connected)
                        num_connectors_detected++;

                if (!enabled[i]) {
                        DRM_DEBUG_KMS("connector %s not enabled, skipping\n",
                                      connector->name);
                        conn_configured |= BIT(i);
                        continue;
                }

                if (connector->force == DRM_FORCE_OFF) {
                        DRM_DEBUG_KMS("connector %s is disabled by user, skipping\n",
                                      connector->name);
                        enabled[i] = false;
                        continue;
                }

                encoder = connector->state->best_encoder;
                if (!encoder || WARN_ON(!connector->state->crtc)) {
                        if (connector->force > DRM_FORCE_OFF)
                                goto bail;

                        DRM_DEBUG_KMS("connector %s has no encoder or crtc, skipping\n",
                                      connector->name);
                        enabled[i] = false;
                        conn_configured |= BIT(i);
                        continue;
                }

                num_connectors_enabled++;

                new_crtc = intel_fb_helper_crtc(fb_helper,
                                                connector->state->crtc);

                /*
                 * Make sure we're not trying to drive multiple connectors
                 * with a single CRTC, since our cloning support may not
                 * match the BIOS.
                 */
                for (j = 0; j < count; j++) {
                        if (crtcs[j] == new_crtc) {
                                DRM_DEBUG_KMS("fallback: cloned configuration\n");
                                goto bail;
                        }
                }

                DRM_DEBUG_KMS("looking for cmdline mode on connector %s\n",
                              connector->name);

                /* go for command line mode first */
                modes[i] = drm_pick_cmdline_mode(fb_conn);

                /* try for preferred next */
                if (!modes[i]) {
                        DRM_DEBUG_KMS("looking for preferred mode on connector %s %d\n",
                                      connector->name, connector->has_tile);
                        modes[i] = drm_has_preferred_mode(fb_conn, width,
                                                          height);
                }

                /* No preferred mode marked by the EDID? Are there any modes? */
                if (!modes[i] && !list_empty(&connector->modes)) {
                        DRM_DEBUG_KMS("using first mode listed on connector %s\n",
                                      connector->name);
                        modes[i] = list_first_entry(&connector->modes,
                                                    struct drm_display_mode,
                                                    head);
                }

                /* last resort: use current mode */
                if (!modes[i]) {
                        /*
                         * IMPORTANT: We want to use the adjusted mode (i.e.
                         * after the panel fitter upscaling) as the initial
                         * config, not the input mode, which is what crtc->mode
                         * usually contains. But since our current
                         * code puts a mode derived from the post-pfit timings
                         * into crtc->mode this works out correctly.
                         *
                         * This is crtc->mode and not crtc->state->mode for the
                         * fastboot check to work correctly. crtc_state->mode has
                         * I915_MODE_FLAG_INHERITED, which we clear to force check
                         * state.
                         */
                        DRM_DEBUG_KMS("looking for current mode on connector %s\n",
                                      connector->name);
                        modes[i] = &connector->state->crtc->mode;
                }
                crtcs[i] = new_crtc;

                DRM_DEBUG_KMS("connector %s on [CRTC:%d:%s]: %dx%d%s\n",
                              connector->name,
                              connector->state->crtc->base.id,
                              connector->state->crtc->name,
                              modes[i]->hdisplay, modes[i]->vdisplay,
                              modes[i]->flags & DRM_MODE_FLAG_INTERLACE ? "i" :"");

                fallback = false;
                conn_configured |= BIT(i);
        }

        if (conn_configured != conn_seq) { /* repeat until no more are found */
                conn_seq = conn_configured;
                goto retry;
        }

        /*
         * If the BIOS didn't enable everything it could, fall back to have the
         * same user experiencing of lighting up as much as possible like the
         * fbdev helper library.
         */
        if (num_connectors_enabled != num_connectors_detected &&
            num_connectors_enabled < INTEL_INFO(dev_priv)->num_pipes) {
                DRM_DEBUG_KMS("fallback: Not all outputs enabled\n");
                DRM_DEBUG_KMS("Enabled: %i, detected: %i\n", num_connectors_enabled,
                              num_connectors_detected);
                fallback = true;
        }

        if (fallback) {
bail:
                DRM_DEBUG_KMS("Not using firmware configuration\n");
                memcpy(enabled, save_enabled, count);
                ret = false;
        }

        drm_modeset_drop_locks(&ctx);
        drm_modeset_acquire_fini(&ctx);

        kfree(save_enabled);
        return ret;
}

static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {
        .initial_config = intel_fb_initial_config,
        .fb_probe = intelfb_create,
};

static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)
{
        /* We rely on the object-free to release the VMA pinning for
         * the info->screen_base mmaping. Leaking the VMA is simpler than
         * trying to rectify all the possible error paths leading here.
         */

        drm_fb_helper_fini(&ifbdev->helper);

        if (ifbdev->vma) {
                mutex_lock(&ifbdev->helper.dev->struct_mutex);
                intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);
                mutex_unlock(&ifbdev->helper.dev->struct_mutex);
        }

        if (ifbdev->fb)
                drm_framebuffer_remove(&ifbdev->fb->base);

        kfree(ifbdev);
}

/*
 * Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.
 * The core display code will have read out the current plane configuration,
 * so we use that to figure out if there's an object for us to use as the
 * fb, and if so, we re-use it for the fbdev configuration.
 *
 * Note we only support a single fb shared across pipes for boot (mostly for
 * fbcon), so we just find the biggest and use that.
 */
static bool intel_fbdev_init_bios(struct drm_device *dev,
                                 struct intel_fbdev *ifbdev)
{
        struct intel_framebuffer *fb = NULL;
        struct drm_crtc *crtc;
        struct intel_crtc *intel_crtc;
        unsigned int max_size = 0;

        /* Find the largest fb */
        for_each_crtc(dev, crtc) {
                struct drm_i915_gem_object *obj =
                        intel_fb_obj(crtc->primary->state->fb);
                intel_crtc = to_intel_crtc(crtc);

                if (!crtc->state->active || !obj) {
                        DRM_DEBUG_KMS("pipe %c not active or no fb, skipping\n",
                                      pipe_name(intel_crtc->pipe));
                        continue;
                }

                if (obj->base.size > max_size) {
                        DRM_DEBUG_KMS("found possible fb from plane %c\n",
                                      pipe_name(intel_crtc->pipe));
                        fb = to_intel_framebuffer(crtc->primary->state->fb);
                        max_size = obj->base.size;
                }
        }

        if (!fb) {
                DRM_DEBUG_KMS("no active fbs found, not using BIOS config\n");
                goto out;
        }

        /* Now make sure all the pipes will fit into it */
        for_each_crtc(dev, crtc) {
                unsigned int cur_size;

                intel_crtc = to_intel_crtc(crtc);

                if (!crtc->state->active) {
                        DRM_DEBUG_KMS("pipe %c not active, skipping\n",
                                      pipe_name(intel_crtc->pipe));
                        continue;
                }

                DRM_DEBUG_KMS("checking plane %c for BIOS fb\n",
                              pipe_name(intel_crtc->pipe));

                /*
                 * See if the plane fb we found above will fit on this
                 * pipe.  Note we need to use the selected fb's pitch and bpp
                 * rather than the current pipe's, since they differ.
                 */
                cur_size = intel_crtc->config->base.adjusted_mode.crtc_hdisplay;
                cur_size = cur_size * fb->base.format->cpp[0];
                if (fb->base.pitches[0] < cur_size) {
                        DRM_DEBUG_KMS("fb not wide enough for plane %c (%d vs %d)\n",
                                      pipe_name(intel_crtc->pipe),
                                      cur_size, fb->base.pitches[0]);
                        fb = NULL;
                        break;
                }

                cur_size = intel_crtc->config->base.adjusted_mode.crtc_vdisplay;
                cur_size = intel_fb_align_height(&fb->base, 0, cur_size);
                cur_size *= fb->base.pitches[0];
                DRM_DEBUG_KMS("pipe %c area: %dx%d, bpp: %d, size: %d\n",
                              pipe_name(intel_crtc->pipe),
                              intel_crtc->config->base.adjusted_mode.crtc_hdisplay,
                              intel_crtc->config->base.adjusted_mode.crtc_vdisplay,
                              fb->base.format->cpp[0] * 8,
                              cur_size);

                if (cur_size > max_size) {
                        DRM_DEBUG_KMS("fb not big enough for plane %c (%d vs %d)\n",
                                      pipe_name(intel_crtc->pipe),
                                      cur_size, max_size);
                        fb = NULL;
                        break;
                }

                DRM_DEBUG_KMS("fb big enough for plane %c (%d >= %d)\n",
                              pipe_name(intel_crtc->pipe),
                              max_size, cur_size);
        }

        if (!fb) {
                DRM_DEBUG_KMS("BIOS fb not suitable for all pipes, not using\n");
                goto out;
        }

        ifbdev->preferred_bpp = fb->base.format->cpp[0] * 8;
        ifbdev->fb = fb;

        drm_framebuffer_get(&ifbdev->fb->base);

        /* Final pass to check if any active pipes don't have fbs */
        for_each_crtc(dev, crtc) {
                intel_crtc = to_intel_crtc(crtc);

                if (!crtc->state->active)
                        continue;

                WARN(!crtc->primary->state->fb,
                     "re-used BIOS config but lost an fb on crtc %d\n",
                     crtc->base.id);
        }


        DRM_DEBUG_KMS("using BIOS fb for initial console\n");
        return true;

out:

        return false;
}

static void intel_fbdev_suspend_worker(struct work_struct *work)
{
        intel_fbdev_set_suspend(&container_of(work,
                                              struct drm_i915_private,
                                              fbdev_suspend_work)->drm,
                                FBINFO_STATE_RUNNING,
                                true);
}

int intel_fbdev_init(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_fbdev *ifbdev;
        int ret;

        if (WARN_ON(INTEL_INFO(dev_priv)->num_pipes == 0))
                return -ENODEV;

        ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
        if (ifbdev == NULL)
                return -ENOMEM;

        lockinit(&ifbdev->hpd_lock, "i915fbdhpdl", 0, LK_CANRECURSE);
        drm_fb_helper_prepare(dev, &ifbdev->helper, &intel_fb_helper_funcs);

        if (!intel_fbdev_init_bios(dev, ifbdev))
                ifbdev->preferred_bpp = 32;

        ret = drm_fb_helper_init(dev, &ifbdev->helper, 4);
        if (ret) {
                kfree(ifbdev);
                return ret;
        }

        dev_priv->fbdev = ifbdev;
        INIT_WORK(&dev_priv->fbdev_suspend_work, intel_fbdev_suspend_worker);

        drm_fb_helper_single_add_all_connectors(&ifbdev->helper);

        return 0;
}

static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
{
        struct intel_fbdev *ifbdev = data;

        /* Due to peculiar init order wrt to hpd handling this is separate. */
        if (drm_fb_helper_initial_config(&ifbdev->helper,
                                         ifbdev->preferred_bpp))
                intel_fbdev_unregister(to_i915(ifbdev->helper.dev));
}

void intel_fbdev_initial_config_async(struct drm_device *dev)
{
        struct intel_fbdev *ifbdev = to_i915(dev)->fbdev;

        if (!ifbdev)
                return;

        ifbdev->cookie = async_schedule(intel_fbdev_initial_config, ifbdev);
}

static void intel_fbdev_sync(struct intel_fbdev *ifbdev)
{
        if (!ifbdev->cookie)
                return;

        /* Only serialises with all preceding async calls, hence +1 */
        async_synchronize_cookie(ifbdev->cookie + 1);
        ifbdev->cookie = 0;
}

void intel_fbdev_unregister(struct drm_i915_private *dev_priv)
{
        struct intel_fbdev *ifbdev = dev_priv->fbdev;

        if (!ifbdev)
                return;

        cancel_work_sync(&dev_priv->fbdev_suspend_work);
        if (!current_is_async())
                intel_fbdev_sync(ifbdev);

        drm_fb_helper_unregister_fbi(&ifbdev->helper);
}

void intel_fbdev_fini(struct drm_i915_private *dev_priv)
{
        struct intel_fbdev *ifbdev = fetch_and_zero(&dev_priv->fbdev);

        if (!ifbdev)
                return;

        intel_fbdev_destroy(ifbdev);
}

#if 0
/* Suspends/resumes fbdev processing of incoming HPD events. When resuming HPD
 * processing, fbdev will perform a full connector reprobe if a hotplug event
 * was received while HPD was suspended.
 */
static void intel_fbdev_hpd_set_suspend(struct intel_fbdev *ifbdev, int state)
{
        bool send_hpd = false;

        mutex_lock(&ifbdev->hpd_lock);
        ifbdev->hpd_suspended = state == FBINFO_STATE_SUSPENDED;
        send_hpd = !ifbdev->hpd_suspended && ifbdev->hpd_waiting;
        ifbdev->hpd_waiting = false;
        mutex_unlock(&ifbdev->hpd_lock);

        if (send_hpd) {
                DRM_DEBUG_KMS("Handling delayed fbcon HPD event\n");
                drm_fb_helper_hotplug_event(&ifbdev->helper);
        }
}
#endif

void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous)
{
#if 0
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_fbdev *ifbdev = dev_priv->fbdev;
        struct fb_info *info;

        if (!ifbdev || !ifbdev->vma)
                return;

        info = ifbdev->helper.fbdev;

        if (synchronous) {
                /* Flush any pending work to turn the console on, and then
                 * wait to turn it off. It must be synchronous as we are
                 * about to suspend or unload the driver.
                 *
                 * Note that from within the work-handler, we cannot flush
                 * ourselves, so only flush outstanding work upon suspend!
                 */
                if (state != FBINFO_STATE_RUNNING)
                        flush_work(&dev_priv->fbdev_suspend_work);

                console_lock();
        } else {
                /*
                 * The console lock can be pretty contented on resume due
                 * to all the printk activity.  Try to keep it out of the hot
                 * path of resume if possible.
                 */
                WARN_ON(state != FBINFO_STATE_RUNNING);
                if (!console_trylock()) {
                        /* Don't block our own workqueue as this can
                         * be run in parallel with other i915.ko tasks.
                         */
                        schedule_work(&dev_priv->fbdev_suspend_work);
                        return;
                }
        }

        /* On resume from hibernation: If the object is shmemfs backed, it has
         * been restored from swap. If the object is stolen however, it will be
         * full of whatever garbage was left in there.
         */
        if (state == FBINFO_STATE_RUNNING &&
            intel_fb_obj(&ifbdev->fb->base)->stolen)
                memset_io(info->screen_base, 0, info->screen_size);

        drm_fb_helper_set_suspend(&ifbdev->helper, state);
        console_unlock();

        intel_fbdev_hpd_set_suspend(ifbdev, state);
#endif
}

void intel_fbdev_output_poll_changed(struct drm_device *dev)
{
        struct intel_fbdev *ifbdev = to_i915(dev)->fbdev;
        bool send_hpd;

        if (!ifbdev)
                return;

        intel_fbdev_sync(ifbdev);

        mutex_lock(&ifbdev->hpd_lock);
        send_hpd = !ifbdev->hpd_suspended;
        ifbdev->hpd_waiting = true;
        mutex_unlock(&ifbdev->hpd_lock);

        if (send_hpd && (ifbdev->vma || ifbdev->helper.deferred_setup))
                drm_fb_helper_hotplug_event(&ifbdev->helper);
}

void intel_fbdev_restore_mode(struct drm_device *dev)
{
        struct intel_fbdev *ifbdev = to_i915(dev)->fbdev;

        if (!ifbdev)
                return;

        intel_fbdev_sync(ifbdev);
        if (!ifbdev->vma)
                return;

#ifdef __DragonFly__
        /* XXX: avoid dead-locking the Xorg on exit */
        if (mutex_is_locked(&dev->mode_config.mutex)) {
                DRM_ERROR("fubar while trying to restore kms_console\n");
                return; /* drm_modeset_unlock_all(dev) ? */
        }
#endif

        if (drm_fb_helper_restore_fbdev_mode_unlocked(&ifbdev->helper) == 0)
                intel_fbdev_invalidate(ifbdev);
}