/**************************************************************************
 *
 * Copyright © 2007 David Airlie
 * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * 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 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 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.
 *
 **************************************************************************/

#include <linux/export.h>

#include <drm/drmP.h>
#include "vmwgfx_drv.h"

#include <drm/ttm/ttm_placement.h>

#define VMW_DIRTY_DELAY (HZ / 30)

struct vmw_fb_par {
        struct vmw_private *vmw_priv;

        void *vmalloc;

        struct vmw_dma_buffer *vmw_bo;
        struct ttm_bo_kmap_obj map;

        u32 pseudo_palette[17];

        unsigned depth;
        unsigned bpp;

        unsigned max_width;
        unsigned max_height;

        void *bo_ptr;
        unsigned bo_size;
        bool bo_iowrite;

        struct {
                spinlock_t lock;
                bool active;
                unsigned x1;
                unsigned y1;
                unsigned x2;
                unsigned y2;
        } dirty;
};

static int vmw_fb_setcolreg(unsigned regno, unsigned red, unsigned green,
                            unsigned blue, unsigned transp,
                            struct fb_info *info)
{
        struct vmw_fb_par *par = info->par;
        u32 *pal = par->pseudo_palette;

        if (regno > 15) {
                DRM_ERROR("Bad regno %u.\n", regno);
                return 1;
        }

        switch (par->depth) {
        case 24:
        case 32:
                pal[regno] = ((red & 0xff00) << 8) |
                              (green & 0xff00) |
                             ((blue  & 0xff00) >> 8);
                break;
        default:
                DRM_ERROR("Bad depth %u, bpp %u.\n", par->depth, par->bpp);
                return 1;
        }

        return 0;
}

static int vmw_fb_check_var(struct fb_var_screeninfo *var,
                            struct fb_info *info)
{
        int depth = var->bits_per_pixel;
        struct vmw_fb_par *par = info->par;
        struct vmw_private *vmw_priv = par->vmw_priv;

        switch (var->bits_per_pixel) {
        case 32:
                depth = (var->transp.length > 0) ? 32 : 24;
                break;
        default:
                DRM_ERROR("Bad bpp %u.\n", var->bits_per_pixel);
                return -EINVAL;
        }

        switch (depth) {
        case 24:
                var->red.offset = 16;
                var->green.offset = 8;
                var->blue.offset = 0;
                var->red.length = 8;
                var->green.length = 8;
                var->blue.length = 8;
                var->transp.length = 0;
                var->transp.offset = 0;
                break;
        case 32:
                var->red.offset = 16;
                var->green.offset = 8;
                var->blue.offset = 0;
                var->red.length = 8;
                var->green.length = 8;
                var->blue.length = 8;
                var->transp.length = 8;
                var->transp.offset = 24;
                break;
        default:
                DRM_ERROR("Bad depth %u.\n", depth);
                return -EINVAL;
        }

        if (!(vmw_priv->capabilities & SVGA_CAP_DISPLAY_TOPOLOGY) &&
            (var->xoffset != 0 || var->yoffset != 0)) {
                DRM_ERROR("Can not handle panning without display topology\n");
                return -EINVAL;
        }

        if ((var->xoffset + var->xres) > par->max_width ||
            (var->yoffset + var->yres) > par->max_height) {
                DRM_ERROR("Requested geom can not fit in framebuffer\n");
                return -EINVAL;
        }

        if (!vmw_kms_validate_mode_vram(vmw_priv,
                                        var->xres * var->bits_per_pixel/8,
                                        var->yoffset + var->yres)) {
                DRM_ERROR("Requested geom can not fit in framebuffer\n");
                return -EINVAL;
        }

        return 0;
}

static int vmw_fb_set_par(struct fb_info *info)
{
        struct vmw_fb_par *par = info->par;
        struct vmw_private *vmw_priv = par->vmw_priv;
        int ret;

        info->fix.line_length = info->var.xres * info->var.bits_per_pixel/8;

        ret = vmw_kms_write_svga(vmw_priv, info->var.xres, info->var.yres,
                                 info->fix.line_length,
                                 par->bpp, par->depth);
        if (ret)
                return ret;

        if (vmw_priv->capabilities & SVGA_CAP_DISPLAY_TOPOLOGY) {
                /* TODO check if pitch and offset changes */
                vmw_write(vmw_priv, SVGA_REG_NUM_GUEST_DISPLAYS, 1);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_ID, 0);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_IS_PRIMARY, true);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_POSITION_X, info->var.xoffset);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_POSITION_Y, info->var.yoffset);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_WIDTH, info->var.xres);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_HEIGHT, info->var.yres);
                vmw_write(vmw_priv, SVGA_REG_DISPLAY_ID, SVGA_ID_INVALID);
        }

        /* This is really helpful since if this fails the user
         * can probably not see anything on the screen.
         */
        WARN_ON(vmw_read(vmw_priv, SVGA_REG_FB_OFFSET) != 0);

        return 0;
}

static int vmw_fb_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info)
{
        return 0;
}

static int vmw_fb_blank(int blank, struct fb_info *info)
{
        return 0;
}

/*
 * Dirty code
 */

static void vmw_fb_dirty_flush(struct vmw_fb_par *par)
{
        struct vmw_private *vmw_priv = par->vmw_priv;
        struct fb_info *info = vmw_priv->fb_info;
        int stride = (info->fix.line_length / 4);
        int *src = (int *)info->screen_base;
        __le32 __iomem *vram_mem = par->bo_ptr;
        unsigned long flags;
        unsigned x, y, w, h;
        int i, k;
        struct {
                uint32_t header;
                SVGAFifoCmdUpdate body;
        } *cmd;

        if (vmw_priv->suspended)
                return;

        spin_lock_irqsave(&par->dirty.lock, flags);
        if (!par->dirty.active) {
                spin_unlock_irqrestore(&par->dirty.lock, flags);
                return;
        }
        x = par->dirty.x1;
        y = par->dirty.y1;
        w = min(par->dirty.x2, info->var.xres) - x;
        h = min(par->dirty.y2, info->var.yres) - y;
        par->dirty.x1 = par->dirty.x2 = 0;
        par->dirty.y1 = par->dirty.y2 = 0;
        spin_unlock_irqrestore(&par->dirty.lock, flags);

        for (i = y * stride; i < info->fix.smem_len / 4; i += stride) {
                for (k = i+x; k < i+x+w && k < info->fix.smem_len / 4; k++)
                        iowrite32(src[k], vram_mem + k);
        }

#if 0
        DRM_INFO("%s, (%u, %u) (%ux%u)\n", __func__, x, y, w, h);
#endif

        cmd = vmw_fifo_reserve(vmw_priv, sizeof(*cmd));
        if (unlikely(cmd == NULL)) {
                DRM_ERROR("Fifo reserve failed.\n");
                return;
        }

        cmd->header = cpu_to_le32(SVGA_CMD_UPDATE);
        cmd->body.x = cpu_to_le32(x);
        cmd->body.y = cpu_to_le32(y);
        cmd->body.width = cpu_to_le32(w);
        cmd->body.height = cpu_to_le32(h);
        vmw_fifo_commit(vmw_priv, sizeof(*cmd));
}

static void vmw_fb_dirty_mark(struct vmw_fb_par *par,
                              unsigned x1, unsigned y1,
                              unsigned width, unsigned height)
{
        struct fb_info *info = par->vmw_priv->fb_info;
        unsigned long flags;
        unsigned x2 = x1 + width;
        unsigned y2 = y1 + height;

        spin_lock_irqsave(&par->dirty.lock, flags);
        if (par->dirty.x1 == par->dirty.x2) {
                par->dirty.x1 = x1;
                par->dirty.y1 = y1;
                par->dirty.x2 = x2;
                par->dirty.y2 = y2;
                /* if we are active start the dirty work
                 * we share the work with the defio system */
                if (par->dirty.active)
                        schedule_delayed_work(&info->deferred_work, VMW_DIRTY_DELAY);
        } else {
                if (x1 < par->dirty.x1)
                        par->dirty.x1 = x1;
                if (y1 < par->dirty.y1)
                        par->dirty.y1 = y1;
                if (x2 > par->dirty.x2)
                        par->dirty.x2 = x2;
                if (y2 > par->dirty.y2)
                        par->dirty.y2 = y2;
        }
        spin_unlock_irqrestore(&par->dirty.lock, flags);
}

static void vmw_deferred_io(struct fb_info *info,
                            struct list_head *pagelist)
{
        struct vmw_fb_par *par = info->par;
        unsigned long start, end, min, max;
        unsigned long flags;
        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;

                spin_lock_irqsave(&par->dirty.lock, flags);
                par->dirty.x1 = 0;
                par->dirty.y1 = y1;
                par->dirty.x2 = info->var.xres;
                par->dirty.y2 = y2;
                spin_unlock_irqrestore(&par->dirty.lock, flags);
        }

        vmw_fb_dirty_flush(par);
};

struct fb_deferred_io vmw_defio = {
        .delay          = VMW_DIRTY_DELAY,
        .deferred_io    = vmw_deferred_io,
};

/*
 * Draw code
 */

static void vmw_fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
        cfb_fillrect(info, rect);
        vmw_fb_dirty_mark(info->par, rect->dx, rect->dy,
                          rect->width, rect->height);
}

static void vmw_fb_copyarea(struct fb_info *info, const struct fb_copyarea *region)
{
        cfb_copyarea(info, region);
        vmw_fb_dirty_mark(info->par, region->dx, region->dy,
                          region->width, region->height);
}

static void vmw_fb_imageblit(struct fb_info *info, const struct fb_image *image)
{
        cfb_imageblit(info, image);
        vmw_fb_dirty_mark(info->par, image->dx, image->dy,
                          image->width, image->height);
}

/*
 * Bring up code
 */

static struct fb_ops vmw_fb_ops = {
        .owner = THIS_MODULE,
        .fb_check_var = vmw_fb_check_var,
        .fb_set_par = vmw_fb_set_par,
        .fb_setcolreg = vmw_fb_setcolreg,
        .fb_fillrect = vmw_fb_fillrect,
        .fb_copyarea = vmw_fb_copyarea,
        .fb_imageblit = vmw_fb_imageblit,
        .fb_pan_display = vmw_fb_pan_display,
        .fb_blank = vmw_fb_blank,
};

static int vmw_fb_create_bo(struct vmw_private *vmw_priv,
                            size_t size, struct vmw_dma_buffer **out)
{
        struct vmw_dma_buffer *vmw_bo;
        struct ttm_place ne_place = vmw_vram_ne_placement.placement[0];
        struct ttm_placement ne_placement;
        int ret;

        ne_placement.num_placement = 1;
        ne_placement.placement = &ne_place;
        ne_placement.num_busy_placement = 1;
        ne_placement.busy_placement = &ne_place;

        ne_place.lpfn = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;

        (void) ttm_write_lock(&vmw_priv->reservation_sem, false);

        vmw_bo = kmalloc(sizeof(*vmw_bo), GFP_KERNEL);
        if (!vmw_bo) {
                ret = -ENOMEM;
                goto err_unlock;
        }

        ret = vmw_dmabuf_init(vmw_priv, vmw_bo, size,
                              &ne_placement,
                              false,
                              &vmw_dmabuf_bo_free);
        if (unlikely(ret != 0))
                goto err_unlock; /* init frees the buffer on failure */

        *out = vmw_bo;

        ttm_write_unlock(&vmw_priv->fbdev_master.lock);

        return 0;

err_unlock:
        ttm_write_unlock(&vmw_priv->fbdev_master.lock);
        return ret;
}

int vmw_fb_init(struct vmw_private *vmw_priv)
{
        struct device *device = &vmw_priv->dev->pdev->dev;
        struct vmw_fb_par *par;
        struct fb_info *info;
        unsigned initial_width, initial_height;
        unsigned fb_width, fb_height;
        unsigned fb_bpp, fb_depth, fb_offset, fb_pitch, fb_size;
        int ret;

        fb_bpp = 32;
        fb_depth = 24;

        /* XXX As shouldn't these be as well. */
        fb_width = min(vmw_priv->fb_max_width, (unsigned)2048);
        fb_height = min(vmw_priv->fb_max_height, (unsigned)2048);

        initial_width = min(vmw_priv->initial_width, fb_width);
        initial_height = min(vmw_priv->initial_height, fb_height);

        fb_pitch = fb_width * fb_bpp / 8;
        fb_size = fb_pitch * fb_height;
        fb_offset = vmw_read(vmw_priv, SVGA_REG_FB_OFFSET);

        info = framebuffer_alloc(sizeof(*par), device);
        if (!info)
                return -ENOMEM;

        /*
         * Par
         */
        vmw_priv->fb_info = info;
        par = info->par;
        par->vmw_priv = vmw_priv;
        par->depth = fb_depth;
        par->bpp = fb_bpp;
        par->vmalloc = NULL;
        par->max_width = fb_width;
        par->max_height = fb_height;

        /*
         * Create buffers and alloc memory
         */
        par->vmalloc = vmalloc(fb_size);
        if (unlikely(par->vmalloc == NULL)) {
                ret = -ENOMEM;
                goto err_free;
        }

        ret = vmw_fb_create_bo(vmw_priv, fb_size, &par->vmw_bo);
        if (unlikely(ret != 0))
                goto err_free;

        ret = ttm_bo_kmap(&par->vmw_bo->base,
                          0,
                          par->vmw_bo->base.num_pages,
                          &par->map);
        if (unlikely(ret != 0))
                goto err_unref;
        par->bo_ptr = ttm_kmap_obj_virtual(&par->map, &par->bo_iowrite);
        par->bo_size = fb_size;

        /*
         * Fixed and var
         */
        strcpy(info->fix.id, "svgadrmfb");
        info->fix.type = FB_TYPE_PACKED_PIXELS;
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        info->fix.type_aux = 0;
        info->fix.xpanstep = 1; /* doing it in hw */
        info->fix.ypanstep = 1; /* doing it in hw */
        info->fix.ywrapstep = 0;
        info->fix.accel = FB_ACCEL_NONE;
        info->fix.line_length = fb_pitch;

        info->fix.smem_start = 0;
        info->fix.smem_len = fb_size;

        info->pseudo_palette = par->pseudo_palette;
        info->screen_base = par->vmalloc;
        info->screen_size = fb_size;

        info->flags = FBINFO_DEFAULT;
        info->fbops = &vmw_fb_ops;

        /* 24 depth per default */
        info->var.red.offset = 16;
        info->var.green.offset = 8;
        info->var.blue.offset = 0;
        info->var.red.length = 8;
        info->var.green.length = 8;
        info->var.blue.length = 8;
        info->var.transp.offset = 0;
        info->var.transp.length = 0;

        info->var.xres_virtual = fb_width;
        info->var.yres_virtual = fb_height;
        info->var.bits_per_pixel = par->bpp;
        info->var.xoffset = 0;
        info->var.yoffset = 0;
        info->var.activate = FB_ACTIVATE_NOW;
        info->var.height = -1;
        info->var.width = -1;

        info->var.xres = initial_width;
        info->var.yres = initial_height;

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

        info->apertures = alloc_apertures(1);
        if (!info->apertures) {
                ret = -ENOMEM;
                goto err_aper;
        }
        info->apertures->ranges[0].base = vmw_priv->vram_start;
        info->apertures->ranges[0].size = vmw_priv->vram_size;

        /*
         * Dirty & Deferred IO
         */
        par->dirty.x1 = par->dirty.x2 = 0;
        par->dirty.y1 = par->dirty.y2 = 0;
        par->dirty.active = true;
        spin_lock_init(&par->dirty.lock);
        info->fbdefio = &vmw_defio;
        fb_deferred_io_init(info);

        ret = register_framebuffer(info);
        if (unlikely(ret != 0))
                goto err_defio;

        return 0;

err_defio:
        fb_deferred_io_cleanup(info);
err_aper:
        ttm_bo_kunmap(&par->map);
err_unref:
        ttm_bo_unref((struct ttm_buffer_object **)&par->vmw_bo);
err_free:
        vfree(par->vmalloc);
        framebuffer_release(info);
        vmw_priv->fb_info = NULL;

        return ret;
}

int vmw_fb_close(struct vmw_private *vmw_priv)
{
        struct fb_info *info;
        struct vmw_fb_par *par;
        struct ttm_buffer_object *bo;

        if (!vmw_priv->fb_info)
                return 0;

        info = vmw_priv->fb_info;
        par = info->par;
        bo = &par->vmw_bo->base;
        par->vmw_bo = NULL;

        /* ??? order */
        fb_deferred_io_cleanup(info);
        unregister_framebuffer(info);

        ttm_bo_kunmap(&par->map);
        ttm_bo_unref(&bo);

        vfree(par->vmalloc);
        framebuffer_release(info);

        return 0;
}

int vmw_fb_off(struct vmw_private *vmw_priv)
{
        struct fb_info *info;
        struct vmw_fb_par *par;
        unsigned long flags;

        if (!vmw_priv->fb_info)
                return -EINVAL;

        info = vmw_priv->fb_info;
        par = info->par;

        spin_lock_irqsave(&par->dirty.lock, flags);
        par->dirty.active = false;
        spin_unlock_irqrestore(&par->dirty.lock, flags);

        flush_delayed_work(&info->deferred_work);

        par->bo_ptr = NULL;
        ttm_bo_kunmap(&par->map);

        vmw_dmabuf_unpin(vmw_priv, par->vmw_bo, false);

        return 0;
}

int vmw_fb_on(struct vmw_private *vmw_priv)
{
        struct fb_info *info;
        struct vmw_fb_par *par;
        unsigned long flags;
        bool dummy;
        int ret;

        if (!vmw_priv->fb_info)
                return -EINVAL;

        info = vmw_priv->fb_info;
        par = info->par;

        /* we are already active */
        if (par->bo_ptr != NULL)
                return 0;

        /* Make sure that all overlays are stoped when we take over */
        vmw_overlay_stop_all(vmw_priv);

        ret = vmw_dmabuf_to_start_of_vram(vmw_priv, par->vmw_bo, true, false);
        if (unlikely(ret != 0)) {
                DRM_ERROR("could not move buffer to start of VRAM\n");
                goto err_no_buffer;
        }

        ret = ttm_bo_kmap(&par->vmw_bo->base,
                          0,
                          par->vmw_bo->base.num_pages,
                          &par->map);
        BUG_ON(ret != 0);
        par->bo_ptr = ttm_kmap_obj_virtual(&par->map, &dummy);

        spin_lock_irqsave(&par->dirty.lock, flags);
        par->dirty.active = true;
        spin_unlock_irqrestore(&par->dirty.lock, flags);

err_no_buffer:
        vmw_fb_set_par(info);

        vmw_fb_dirty_mark(par, 0, 0, info->var.xres, info->var.yres);

        /* If there already was stuff dirty we wont
         * schedule a new work, so lets do it now */
        schedule_delayed_work(&info->deferred_work, 0);

        return 0;
}