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

#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/i915_drm.h>

#include "i915_drv.h"
#include "intel_display_types.h"
#include "intel_fbdev.h"
#include "intel_frontbuffer.h"

static struct intel_frontbuffer *to_frontbuffer(struct intel_fbdev *ifbdev)
{
        return ifbdev->fb->frontbuffer;
}

static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
{
        intel_frontbuffer_invalidate(to_frontbuffer(ifbdev), ORIGIN_CPU);
}

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;
}

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;
}

static struct fb_ops intelfb_ops = {
        .owner = THIS_MODULE,
        DRM_FB_HELPER_DEFAULT_OPS,
        .fb_set_par = intel_fbdev_set_par,
        .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,
        .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;

        /* 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 = ERR_PTR(-ENODEV);
        if (size * 2 < dev_priv->stolen_usable_size)
                obj = i915_gem_object_create_stolen(dev_priv, size);
        if (IS_ERR(obj))
                obj = i915_gem_object_create_shmem(dev_priv, size);
        if (IS_ERR(obj)) {
                DRM_ERROR("failed to allocate framebuffer\n");
                return PTR_ERR(obj);
        }

        fb = intel_framebuffer_create(obj, &mode_cmd);
        i915_gem_object_put(obj);
        if (IS_ERR(fb))
                return PTR_ERR(fb);

        ifbdev->fb = to_intel_framebuffer(fb);
        return 0;
}

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,
        };
        intel_wakeref_t wakeref;
        struct fb_info *info;
        struct i915_vma *vma;
        unsigned long flags = 0;
        bool prealloc = false;
        void __iomem *vaddr;
        int ret;

        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;
        }

        wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);

        /* 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;
        }

        intel_frontbuffer_flush(to_frontbuffer(ifbdev), 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;
        }

        ifbdev->helper.fb = &ifbdev->fb->base;

        info->fbops = &intelfb_ops;

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

        /* Our framebuffer is the entirety of fbdev's system memory */
        info->fix.smem_start =
                (unsigned long)(ggtt->gmadr.start + vma->node.start);
        info->fix.smem_len = vma->node.size;

        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;
        }
        info->screen_base = vaddr;
        info->screen_size = vma->node.size;

        drm_fb_helper_fill_info(info, &ifbdev->helper, sizes);

        /* 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 (vma->obj->stolen && !prealloc)
                memset_io(info->screen_base, 0, info->screen_size);

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

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

        intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
        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->runtime_pm, wakeref);
        return ret;
}

static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {
        .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)
                intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);

        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 = crtc->state->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 = crtc->state->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),
                              crtc->state->adjusted_mode.crtc_hdisplay,
                              crtc->state->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(!HAS_DISPLAY(dev_priv) || !INTEL_DISPLAY_ENABLED(dev_priv)))
                return -ENODEV;

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

        mutex_init(&ifbdev->hpd_lock);
        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);
}

/* 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);
        }
}

void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous)
{
        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);
}

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;

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