/*
 * Copyright © 2013 Red Hat
 *
 * 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/module.h>
#include <linux/fb.h>

#include "drmP.h"
#include "drm/drm.h"
#include "drm/drm_crtc.h"
#include "drm/drm_crtc_helper.h"
#include "qxl_drv.h"

#include "qxl_object.h"
#include "drm_fb_helper.h"

#define QXL_DIRTY_DELAY (HZ / 30)

struct qxl_fbdev {
        struct drm_fb_helper helper;
        struct qxl_framebuffer  qfb;
        struct qxl_device       *qdev;

        spinlock_t delayed_ops_lock;
        struct list_head delayed_ops;
        void *shadow;
        int size;

        /* dirty memory logging */
        struct {
                spinlock_t lock;
                unsigned x1;
                unsigned y1;
                unsigned x2;
                unsigned y2;
        } dirty;
};

static void qxl_fb_image_init(struct qxl_fb_image *qxl_fb_image,
                              struct qxl_device *qdev, struct fb_info *info,
                              const struct fb_image *image)
{
        qxl_fb_image->qdev = qdev;
        if (info) {
                qxl_fb_image->visual = info->fix.visual;
                if (qxl_fb_image->visual == FB_VISUAL_TRUECOLOR ||
                    qxl_fb_image->visual == FB_VISUAL_DIRECTCOLOR)
                        memcpy(&qxl_fb_image->pseudo_palette,
                               info->pseudo_palette,
                               sizeof(qxl_fb_image->pseudo_palette));
        } else {
                 /* fallback */
                if (image->depth == 1)
                        qxl_fb_image->visual = FB_VISUAL_MONO10;
                else
                        qxl_fb_image->visual = FB_VISUAL_DIRECTCOLOR;
        }
        if (image) {
                memcpy(&qxl_fb_image->fb_image, image,
                       sizeof(qxl_fb_image->fb_image));
        }
}

static void qxl_fb_dirty_flush(struct fb_info *info)
{
        struct qxl_fbdev *qfbdev = info->par;
        struct qxl_device *qdev = qfbdev->qdev;
        struct qxl_fb_image qxl_fb_image;
        struct fb_image *image = &qxl_fb_image.fb_image;
        unsigned long flags;
        u32 x1, x2, y1, y2;

        /* TODO: hard coding 32 bpp */
        int stride = qfbdev->qfb.base.pitches[0];

        spin_lock_irqsave(&qfbdev->dirty.lock, flags);

        x1 = qfbdev->dirty.x1;
        x2 = qfbdev->dirty.x2;
        y1 = qfbdev->dirty.y1;
        y2 = qfbdev->dirty.y2;
        qfbdev->dirty.x1 = 0;
        qfbdev->dirty.x2 = 0;
        qfbdev->dirty.y1 = 0;
        qfbdev->dirty.y2 = 0;

        spin_unlock_irqrestore(&qfbdev->dirty.lock, flags);

        /*
         * we are using a shadow draw buffer, at qdev->surface0_shadow
         */
        qxl_io_log(qdev, "dirty x[%d, %d], y[%d, %d]", x1, x2, y1, y2);
        image->dx = x1;
        image->dy = y1;
        image->width = x2 - x1 + 1;
        image->height = y2 - y1 + 1;
        image->fg_color = 0xffffffff; /* unused, just to avoid uninitialized
                                         warnings */
        image->bg_color = 0;
        image->depth = 32;           /* TODO: take from somewhere? */
        image->cmap.start = 0;
        image->cmap.len = 0;
        image->cmap.red = NULL;
        image->cmap.green = NULL;
        image->cmap.blue = NULL;
        image->cmap.transp = NULL;
        image->data = qfbdev->shadow + (x1 * 4) + (stride * y1);

        qxl_fb_image_init(&qxl_fb_image, qdev, info, NULL);
        qxl_draw_opaque_fb(&qxl_fb_image, stride);
}

static void qxl_dirty_update(struct qxl_fbdev *qfbdev,
                             int x, int y, int width, int height)
{
        struct qxl_device *qdev = qfbdev->qdev;
        unsigned long flags;
        int x2, y2;

        x2 = x + width - 1;
        y2 = y + height - 1;

        spin_lock_irqsave(&qfbdev->dirty.lock, flags);

        if ((qfbdev->dirty.y2 - qfbdev->dirty.y1) &&
            (qfbdev->dirty.x2 - qfbdev->dirty.x1)) {
                if (qfbdev->dirty.y1 < y)
                        y = qfbdev->dirty.y1;
                if (qfbdev->dirty.y2 > y2)
                        y2 = qfbdev->dirty.y2;
                if (qfbdev->dirty.x1 < x)
                        x = qfbdev->dirty.x1;
                if (qfbdev->dirty.x2 > x2)
                        x2 = qfbdev->dirty.x2;
        }

        qfbdev->dirty.x1 = x;
        qfbdev->dirty.x2 = x2;
        qfbdev->dirty.y1 = y;
        qfbdev->dirty.y2 = y2;

        spin_unlock_irqrestore(&qfbdev->dirty.lock, flags);

        schedule_work(&qdev->fb_work);
}

static void qxl_deferred_io(struct fb_info *info,
                            struct list_head *pagelist)
{
        struct qxl_fbdev *qfbdev = 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;
                qxl_dirty_update(qfbdev, 0, y1, info->var.xres, y2 - y1);
        }
};

static struct fb_deferred_io qxl_defio = {
        .delay          = QXL_DIRTY_DELAY,
        .deferred_io    = qxl_deferred_io,
};

static void qxl_fb_fillrect(struct fb_info *info,
                            const struct fb_fillrect *rect)
{
        struct qxl_fbdev *qfbdev = info->par;

        drm_fb_helper_sys_fillrect(info, rect);
        qxl_dirty_update(qfbdev, rect->dx, rect->dy, rect->width,
                         rect->height);
}

static void qxl_fb_copyarea(struct fb_info *info,
                            const struct fb_copyarea *area)
{
        struct qxl_fbdev *qfbdev = info->par;

        drm_fb_helper_sys_copyarea(info, area);
        qxl_dirty_update(qfbdev, area->dx, area->dy, area->width,
                         area->height);
}

static void qxl_fb_imageblit(struct fb_info *info,
                             const struct fb_image *image)
{
        struct qxl_fbdev *qfbdev = info->par;

        drm_fb_helper_sys_imageblit(info, image);
        qxl_dirty_update(qfbdev, image->dx, image->dy, image->width,
                         image->height);
}

static void qxl_fb_work(struct work_struct *work)
{
        struct qxl_device *qdev = container_of(work, struct qxl_device, fb_work);
        struct qxl_fbdev *qfbdev = qdev->mode_info.qfbdev;

        qxl_fb_dirty_flush(qfbdev->helper.fbdev);
}

int qxl_fb_init(struct qxl_device *qdev)
{
        INIT_WORK(&qdev->fb_work, qxl_fb_work);
        return 0;
}

static struct fb_ops qxlfb_ops = {
        .owner = THIS_MODULE,
        .fb_check_var = drm_fb_helper_check_var,
        .fb_set_par = drm_fb_helper_set_par, /* TODO: copy vmwgfx */
        .fb_fillrect = qxl_fb_fillrect,
        .fb_copyarea = qxl_fb_copyarea,
        .fb_imageblit = qxl_fb_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 void qxlfb_destroy_pinned_object(struct drm_gem_object *gobj)
{
        struct qxl_bo *qbo = gem_to_qxl_bo(gobj);
        int ret;

        ret = qxl_bo_reserve(qbo, false);
        if (likely(ret == 0)) {
                qxl_bo_kunmap(qbo);
                qxl_bo_unpin(qbo);
                qxl_bo_unreserve(qbo);
        }
        drm_gem_object_unreference_unlocked(gobj);
}

int qxl_get_handle_for_primary_fb(struct qxl_device *qdev,
                                  struct drm_file *file_priv,
                                  uint32_t *handle)
{
        int r;
        struct drm_gem_object *gobj = qdev->fbdev_qfb->obj;

        BUG_ON(!gobj);
        /* drm_get_handle_create adds a reference - good */
        r = drm_gem_handle_create(file_priv, gobj, handle);
        if (r)
                return r;
        return 0;
}

static int qxlfb_create_pinned_object(struct qxl_fbdev *qfbdev,
                                      const struct drm_mode_fb_cmd2 *mode_cmd,
                                      struct drm_gem_object **gobj_p)
{
        struct qxl_device *qdev = qfbdev->qdev;
        struct drm_gem_object *gobj = NULL;
        struct qxl_bo *qbo = NULL;
        int ret;
        int aligned_size, size;
        int height = mode_cmd->height;
        int bpp;
        int depth;

        drm_fb_get_bpp_depth(mode_cmd->pixel_format, &bpp, &depth);

        size = mode_cmd->pitches[0] * height;
        aligned_size = ALIGN(size, PAGE_SIZE);
        /* TODO: unallocate and reallocate surface0 for real. Hack to just
         * have a large enough surface0 for 1024x768 Xorg 32bpp mode */
        ret = qxl_gem_object_create(qdev, aligned_size, 0,
                                    QXL_GEM_DOMAIN_SURFACE,
                                    false, /* is discardable */
                                    false, /* is kernel (false means device) */
                                    NULL,
                                    &gobj);
        if (ret) {
                pr_err("failed to allocate framebuffer (%d)\n",
                       aligned_size);
                return -ENOMEM;
        }
        qbo = gem_to_qxl_bo(gobj);

        qbo->surf.width = mode_cmd->width;
        qbo->surf.height = mode_cmd->height;
        qbo->surf.stride = mode_cmd->pitches[0];
        qbo->surf.format = SPICE_SURFACE_FMT_32_xRGB;
        ret = qxl_bo_reserve(qbo, false);
        if (unlikely(ret != 0))
                goto out_unref;
        ret = qxl_bo_pin(qbo, QXL_GEM_DOMAIN_SURFACE, NULL);
        if (ret) {
                qxl_bo_unreserve(qbo);
                goto out_unref;
        }
        ret = qxl_bo_kmap(qbo, NULL);
        qxl_bo_unreserve(qbo); /* unreserve, will be mmaped */
        if (ret)
                goto out_unref;

        *gobj_p = gobj;
        return 0;
out_unref:
        qxlfb_destroy_pinned_object(gobj);
        *gobj_p = NULL;
        return ret;
}

static int qxlfb_create(struct qxl_fbdev *qfbdev,
                        struct drm_fb_helper_surface_size *sizes)
{
        struct qxl_device *qdev = qfbdev->qdev;
        struct fb_info *info;
        struct drm_framebuffer *fb = NULL;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct drm_gem_object *gobj = NULL;
        struct qxl_bo *qbo = NULL;
        int ret;
        int size;
        int bpp = sizes->surface_bpp;
        int depth = sizes->surface_depth;
        void *shadow;

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

        mode_cmd.pitches[0] = ALIGN(mode_cmd.width * ((bpp + 1) / 8), 64);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(bpp, depth);

        ret = qxlfb_create_pinned_object(qfbdev, &mode_cmd, &gobj);
        qbo = gem_to_qxl_bo(gobj);
        QXL_INFO(qdev, "%s: %dx%d %d\n", __func__, mode_cmd.width,
                 mode_cmd.height, mode_cmd.pitches[0]);

        shadow = vmalloc(mode_cmd.pitches[0] * mode_cmd.height);
        /* TODO: what's the usual response to memory allocation errors? */
        BUG_ON(!shadow);
        QXL_INFO(qdev,
        "surface0 at gpu offset %lld, mmap_offset %lld (virt %p, shadow %p)\n",
                 qxl_bo_gpu_offset(qbo),
                 qxl_bo_mmap_offset(qbo),
                 qbo->kptr,
                 shadow);
        size = mode_cmd.pitches[0] * mode_cmd.height;

        info = drm_fb_helper_alloc_fbi(&qfbdev->helper);
        if (IS_ERR(info)) {
                ret = PTR_ERR(info);
                goto out_unref;
        }

        info->par = qfbdev;

        qxl_framebuffer_init(qdev->ddev, &qfbdev->qfb, &mode_cmd, gobj);

        fb = &qfbdev->qfb.base;

        /* setup helper with fb data */
        qfbdev->helper.fb = fb;

        qfbdev->shadow = shadow;
        strcpy(info->fix.id, "qxldrmfb");

        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->depth);

        info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_COPYAREA | FBINFO_HWACCEL_FILLRECT;
        info->fbops = &qxlfb_ops;

        /*
         * TODO: using gobj->size in various places in this function. Not sure
         * what the difference between the different sizes is.
         */
        info->fix.smem_start = qdev->vram_base; /* TODO - correct? */
        info->fix.smem_len = gobj->size;
        info->screen_base = qfbdev->shadow;
        info->screen_size = gobj->size;

        drm_fb_helper_fill_var(info, &qfbdev->helper, sizes->fb_width,
                               sizes->fb_height);

        /* setup aperture base/size for vesafb takeover */
        info->apertures->ranges[0].base = qdev->ddev->mode_config.fb_base;
        info->apertures->ranges[0].size = qdev->vram_size;

        info->fix.mmio_start = 0;
        info->fix.mmio_len = 0;

        if (info->screen_base == NULL) {
                ret = -ENOSPC;
                goto out_destroy_fbi;
        }

        info->fbdefio = &qxl_defio;
        fb_deferred_io_init(info);

        qdev->fbdev_info = info;
        qdev->fbdev_qfb = &qfbdev->qfb;
        DRM_INFO("fb mappable at 0x%lX, size %lu\n",  info->fix.smem_start, (unsigned long)info->screen_size);
        DRM_INFO("fb: depth %d, pitch %d, width %d, height %d\n", fb->depth, fb->pitches[0], fb->width, fb->height);
        return 0;

out_destroy_fbi:
        drm_fb_helper_release_fbi(&qfbdev->helper);
out_unref:
        if (qbo) {
                ret = qxl_bo_reserve(qbo, false);
                if (likely(ret == 0)) {
                        qxl_bo_kunmap(qbo);
                        qxl_bo_unpin(qbo);
                        qxl_bo_unreserve(qbo);
                }
        }
        if (fb && ret) {
                drm_gem_object_unreference(gobj);
                drm_framebuffer_cleanup(fb);
                kfree(fb);
        }
        drm_gem_object_unreference(gobj);
        return ret;
}

static int qxl_fb_find_or_create_single(
                struct drm_fb_helper *helper,
                struct drm_fb_helper_surface_size *sizes)
{
        struct qxl_fbdev *qfbdev =
                container_of(helper, struct qxl_fbdev, helper);
        int new_fb = 0;
        int ret;

        if (!helper->fb) {
                ret = qxlfb_create(qfbdev, sizes);
                if (ret)
                        return ret;
                new_fb = 1;
        }
        return new_fb;
}

static int qxl_fbdev_destroy(struct drm_device *dev, struct qxl_fbdev *qfbdev)
{
        struct qxl_framebuffer *qfb = &qfbdev->qfb;

        drm_fb_helper_unregister_fbi(&qfbdev->helper);
        drm_fb_helper_release_fbi(&qfbdev->helper);

        if (qfb->obj) {
                qxlfb_destroy_pinned_object(qfb->obj);
                qfb->obj = NULL;
        }
        drm_fb_helper_fini(&qfbdev->helper);
        vfree(qfbdev->shadow);
        drm_framebuffer_cleanup(&qfb->base);

        return 0;
}

static const struct drm_fb_helper_funcs qxl_fb_helper_funcs = {
        .fb_probe = qxl_fb_find_or_create_single,
};

int qxl_fbdev_init(struct qxl_device *qdev)
{
        struct qxl_fbdev *qfbdev;
        int bpp_sel = 32; /* TODO: parameter from somewhere? */
        int ret;

        qfbdev = kzalloc(sizeof(struct qxl_fbdev), GFP_KERNEL);
        if (!qfbdev)
                return -ENOMEM;

        qfbdev->qdev = qdev;
        qdev->mode_info.qfbdev = qfbdev;
        spin_lock_init(&qfbdev->delayed_ops_lock);
        spin_lock_init(&qfbdev->dirty.lock);
        INIT_LIST_HEAD(&qfbdev->delayed_ops);

        drm_fb_helper_prepare(qdev->ddev, &qfbdev->helper,
                              &qxl_fb_helper_funcs);

        ret = drm_fb_helper_init(qdev->ddev, &qfbdev->helper,
                                 qxl_num_crtc /* num_crtc - QXL supports just 1 */,
                                 QXLFB_CONN_LIMIT);
        if (ret)
                goto free;

        ret = drm_fb_helper_single_add_all_connectors(&qfbdev->helper);
        if (ret)
                goto fini;

        ret = drm_fb_helper_initial_config(&qfbdev->helper, bpp_sel);
        if (ret)
                goto fini;

        return 0;

fini:
        drm_fb_helper_fini(&qfbdev->helper);
free:
        kfree(qfbdev);
        return ret;
}

void qxl_fbdev_fini(struct qxl_device *qdev)
{
        if (!qdev->mode_info.qfbdev)
                return;

        qxl_fbdev_destroy(qdev->ddev, qdev->mode_info.qfbdev);
        kfree(qdev->mode_info.qfbdev);
        qdev->mode_info.qfbdev = NULL;
}

void qxl_fbdev_set_suspend(struct qxl_device *qdev, int state)
{
        drm_fb_helper_set_suspend(&qdev->mode_info.qfbdev->helper, state);
}

bool qxl_fbdev_qobj_is_fb(struct qxl_device *qdev, struct qxl_bo *qobj)
{
        if (qobj == gem_to_qxl_bo(qdev->mode_info.qfbdev->qfb.obj))
                return true;
        return false;
}