/*
 * Copyright (C) 2013-2017 Oracle Corporation
 * This file is based on ast_fb.c
 * Copyright 2012 Red Hat Inc.
 *
 * 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * Authors: Dave Airlie <airlied@redhat.com>
 *          Michael Thayer <michael.thayer@oracle.com,
 */
#include <linux/module.h>
#include <linux/kernel.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/fb.h>
#include <linux/init.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>

#include "vbox_drv.h"
#include "vboxvideo.h"

#define VBOX_DIRTY_DELAY (HZ / 30)
/**
 * Tell the host about dirty rectangles to update.
 */
static void vbox_dirty_update(struct vbox_fbdev *fbdev,
                              int x, int y, int width, int height)
{
        struct drm_gem_object *obj;
        struct vbox_bo *bo;
        int ret = -EBUSY;
        bool store_for_later = false;
        int x2, y2;
        unsigned long flags;
        struct drm_clip_rect rect;

        obj = fbdev->afb.obj;
        bo = gem_to_vbox_bo(obj);

        /*
         * try and reserve the BO, if we fail with busy
         * then the BO is being moved and we should
         * store up the damage until later.
         */
        if (drm_can_sleep())
                ret = vbox_bo_reserve(bo, true);
        if (ret) {
                if (ret != -EBUSY)
                        return;

                store_for_later = true;
        }

        x2 = x + width - 1;
        y2 = y + height - 1;
        spin_lock_irqsave(&fbdev->dirty_lock, flags);

        if (fbdev->y1 < y)
                y = fbdev->y1;
        if (fbdev->y2 > y2)
                y2 = fbdev->y2;
        if (fbdev->x1 < x)
                x = fbdev->x1;
        if (fbdev->x2 > x2)
                x2 = fbdev->x2;

        if (store_for_later) {
                fbdev->x1 = x;
                fbdev->x2 = x2;
                fbdev->y1 = y;
                fbdev->y2 = y2;
                spin_unlock_irqrestore(&fbdev->dirty_lock, flags);
                return;
        }

        fbdev->x1 = INT_MAX;
        fbdev->y1 = INT_MAX;
        fbdev->x2 = 0;
        fbdev->y2 = 0;

        spin_unlock_irqrestore(&fbdev->dirty_lock, flags);

        /*
         * Not sure why the original code subtracted 1 here, but I will keep
         * it that way to avoid unnecessary differences.
         */
        rect.x1 = x;
        rect.x2 = x2 + 1;
        rect.y1 = y;
        rect.y2 = y2 + 1;
        vbox_framebuffer_dirty_rectangles(&fbdev->afb.base, &rect, 1);

        vbox_bo_unreserve(bo);
}

#ifdef CONFIG_FB_DEFERRED_IO
static void vbox_deferred_io(struct fb_info *info, struct list_head *pagelist)
{
        struct vbox_fbdev *fbdev = info->par;
        unsigned long start, end, min, max;
        struct page *page;
        int y1, y2;

        min = ULONG_MAX;
        max = 0;
        list_for_each_entry(page, pagelist, lru) {
                start = page->index << PAGE_SHIFT;
                end = start + PAGE_SIZE - 1;
                min = min(min, start);
                max = max(max, end);
        }

        if (min < max) {
                y1 = min / info->fix.line_length;
                y2 = (max / info->fix.line_length) + 1;
                DRM_INFO("%s: Calling dirty update: 0, %d, %d, %d\n",
                         __func__, y1, info->var.xres, y2 - y1 - 1);
                vbox_dirty_update(fbdev, 0, y1, info->var.xres, y2 - y1 - 1);
        }
}

static struct fb_deferred_io vbox_defio = {
        .delay = VBOX_DIRTY_DELAY,
        .deferred_io = vbox_deferred_io,
};
#endif

static void vbox_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        struct vbox_fbdev *fbdev = info->par;

        sys_fillrect(info, rect);
        vbox_dirty_update(fbdev, rect->dx, rect->dy, rect->width, rect->height);
}

static void vbox_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
        struct vbox_fbdev *fbdev = info->par;

        sys_copyarea(info, area);
        vbox_dirty_update(fbdev, area->dx, area->dy, area->width, area->height);
}

static void vbox_imageblit(struct fb_info *info, const struct fb_image *image)
{
        struct vbox_fbdev *fbdev = info->par;

        sys_imageblit(info, image);
        vbox_dirty_update(fbdev, image->dx, image->dy, image->width,
                          image->height);
}

static struct fb_ops vboxfb_ops = {
        .owner = THIS_MODULE,
        .fb_check_var = drm_fb_helper_check_var,
        .fb_set_par = drm_fb_helper_set_par,
        .fb_fillrect = vbox_fillrect,
        .fb_copyarea = vbox_copyarea,
        .fb_imageblit = vbox_imageblit,
        .fb_pan_display = drm_fb_helper_pan_display,
        .fb_blank = drm_fb_helper_blank,
        .fb_setcmap = drm_fb_helper_setcmap,
        .fb_debug_enter = drm_fb_helper_debug_enter,
        .fb_debug_leave = drm_fb_helper_debug_leave,
};

static int vboxfb_create_object(struct vbox_fbdev *fbdev,
                                struct DRM_MODE_FB_CMD *mode_cmd,
                                struct drm_gem_object **gobj_p)
{
        struct drm_device *dev = fbdev->helper.dev;
        u32 size;
        struct drm_gem_object *gobj;
        u32 pitch = mode_cmd->pitches[0];
        int ret;

        size = pitch * mode_cmd->height;
        ret = vbox_gem_create(dev, size, true, &gobj);
        if (ret)
                return ret;

        *gobj_p = gobj;

        return 0;
}

static int vboxfb_create(struct drm_fb_helper *helper,
                         struct drm_fb_helper_surface_size *sizes)
{
        struct vbox_fbdev *fbdev =
            container_of(helper, struct vbox_fbdev, helper);
        struct drm_device *dev = fbdev->helper.dev;
        struct DRM_MODE_FB_CMD mode_cmd;
        struct drm_framebuffer *fb;
        struct fb_info *info;
        struct device *device = &dev->pdev->dev;
        struct drm_gem_object *gobj;
        struct vbox_bo *bo;
        int size, ret;
        u32 pitch;

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;
        pitch = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                          sizes->surface_depth);
        mode_cmd.pitches[0] = pitch;

        size = pitch * mode_cmd.height;

        ret = vboxfb_create_object(fbdev, &mode_cmd, &gobj);
        if (ret) {
                DRM_ERROR("failed to create fbcon backing object %d\n", ret);
                return ret;
        }

        ret = vbox_framebuffer_init(dev, &fbdev->afb, &mode_cmd, gobj);
        if (ret)
                return ret;

        bo = gem_to_vbox_bo(gobj);

        ret = vbox_bo_reserve(bo, false);
        if (ret)
                return ret;

        ret = vbox_bo_pin(bo, TTM_PL_FLAG_VRAM, NULL);
        if (ret) {
                vbox_bo_unreserve(bo);
                return ret;
        }

        ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
        vbox_bo_unreserve(bo);
        if (ret) {
                DRM_ERROR("failed to kmap fbcon\n");
                return ret;
        }

        info = framebuffer_alloc(0, device);
        if (!info)
                return -ENOMEM;
        info->par = fbdev;

        fbdev->size = size;

        fb = &fbdev->afb.base;
        fbdev->helper.fb = fb;
        fbdev->helper.fbdev = info;

        strcpy(info->fix.id, "vboxdrmfb");

        /*
         * The last flag forces a mode set on VT switches even if the kernel
         * does not think it is needed.
         */
        info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT |
                      FBINFO_MISC_ALWAYS_SETPAR;
        info->fbops = &vboxfb_ops;

        ret = fb_alloc_cmap(&info->cmap, 256, 0);
        if (ret)
                return -ENOMEM;

        /*
         * This seems to be done for safety checking that the framebuffer
         * is not registered twice by different drivers.
         */
        info->apertures = alloc_apertures(1);
        if (!info->apertures)
                return -ENOMEM;
        info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
        info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);

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

        info->screen_base = bo->kmap.virtual;
        info->screen_size = size;

#ifdef CONFIG_FB_DEFERRED_IO
        info->fbdefio = &vbox_defio;
        fb_deferred_io_init(info);
#endif

        info->pixmap.flags = FB_PIXMAP_SYSTEM;

        DRM_DEBUG_KMS("allocated %dx%d\n", fb->width, fb->height);

        return 0;
}

static void vbox_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
                              u16 blue, int regno)
{
}

static void vbox_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
                              u16 *blue, int regno)
{
        *red = regno;
        *green = regno;
        *blue = regno;
}

static struct drm_fb_helper_funcs vbox_fb_helper_funcs = {
        .gamma_set = vbox_fb_gamma_set,
        .gamma_get = vbox_fb_gamma_get,
        .fb_probe = vboxfb_create,
};

void vbox_fbdev_fini(struct drm_device *dev)
{
        struct vbox_private *vbox = dev->dev_private;
        struct vbox_fbdev *fbdev = vbox->fbdev;
        struct vbox_framebuffer *afb = &fbdev->afb;

        drm_fb_helper_unregister_fbi(&fbdev->helper);

        if (afb->obj) {
                struct vbox_bo *bo = gem_to_vbox_bo(afb->obj);

                if (!vbox_bo_reserve(bo, false)) {
                        if (bo->kmap.virtual)
                                ttm_bo_kunmap(&bo->kmap);
                        /*
                         * QXL does this, but is it really needed before
                         * freeing?
                         */
                        if (bo->pin_count)
                                vbox_bo_unpin(bo);
                        vbox_bo_unreserve(bo);
                }
                drm_gem_object_unreference_unlocked(afb->obj);
                afb->obj = NULL;
        }
        drm_fb_helper_fini(&fbdev->helper);

        drm_framebuffer_unregister_private(&afb->base);
        drm_framebuffer_cleanup(&afb->base);
}

int vbox_fbdev_init(struct drm_device *dev)
{
        struct vbox_private *vbox = dev->dev_private;
        struct vbox_fbdev *fbdev;
        int ret;

        fbdev = devm_kzalloc(dev->dev, sizeof(*fbdev), GFP_KERNEL);
        if (!fbdev)
                return -ENOMEM;

        vbox->fbdev = fbdev;
        spin_lock_init(&fbdev->dirty_lock);

        drm_fb_helper_prepare(dev, &fbdev->helper, &vbox_fb_helper_funcs);
        ret = drm_fb_helper_init(dev, &fbdev->helper, vbox->num_crtcs);
        if (ret)
                return ret;

        ret = drm_fb_helper_single_add_all_connectors(&fbdev->helper);
        if (ret)
                goto err_fini;

        /* disable all the possible outputs/crtcs before entering KMS mode */
        drm_helper_disable_unused_functions(dev);

        ret = drm_fb_helper_initial_config(&fbdev->helper, 32);
        if (ret)
                goto err_fini;

        return 0;

err_fini:
        drm_fb_helper_fini(&fbdev->helper);
        return ret;
}

void vbox_fbdev_set_base(struct vbox_private *vbox, unsigned long gpu_addr)
{
        struct fb_info *fbdev = vbox->fbdev->helper.fbdev;

        fbdev->fix.smem_start = fbdev->apertures->ranges[0].base + gpu_addr;
        fbdev->fix.smem_len = vbox->available_vram_size - gpu_addr;
}