/******************************************************************************
 *
 * COPYRIGHT © 2014-2015 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 "vmwgfx_kms.h"
#include "device_include/svga3d_surfacedefs.h"
#include <drm/drm_plane_helper.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>


#define vmw_crtc_to_stdu(x) \
        container_of(x, struct vmw_screen_target_display_unit, base.crtc)
#define vmw_encoder_to_stdu(x) \
        container_of(x, struct vmw_screen_target_display_unit, base.encoder)
#define vmw_connector_to_stdu(x) \
        container_of(x, struct vmw_screen_target_display_unit, base.connector)



enum stdu_content_type {
        SAME_AS_DISPLAY = 0,
        SEPARATE_SURFACE,
        SEPARATE_DMA
};

/**
 * struct vmw_stdu_dirty - closure structure for the update functions
 *
 * @base: The base type we derive from. Used by vmw_kms_helper_dirty().
 * @transfer: Transfer direction for DMA command.
 * @left: Left side of bounding box.
 * @right: Right side of bounding box.
 * @top: Top side of bounding box.
 * @bottom: Bottom side of bounding box.
 * @fb_left: Left side of the framebuffer/content bounding box
 * @fb_top: Top of the framebuffer/content bounding box
 * @buf: DMA buffer when DMA-ing between buffer and screen targets.
 * @sid: Surface ID when copying between surface and screen targets.
 */
struct vmw_stdu_dirty {
        struct vmw_kms_dirty base;
        SVGA3dTransferType  transfer;
        s32 left, right, top, bottom;
        s32 fb_left, fb_top;
        u32 pitch;
        union {
                struct vmw_dma_buffer *buf;
                u32 sid;
        };
};

/*
 * SVGA commands that are used by this code. Please see the device headers
 * for explanation.
 */
struct vmw_stdu_update {
        SVGA3dCmdHeader header;
        SVGA3dCmdUpdateGBScreenTarget body;
};

struct vmw_stdu_dma {
        SVGA3dCmdHeader     header;
        SVGA3dCmdSurfaceDMA body;
};

struct vmw_stdu_surface_copy {
        SVGA3dCmdHeader      header;
        SVGA3dCmdSurfaceCopy body;
};


/**
 * struct vmw_screen_target_display_unit
 *
 * @base: VMW specific DU structure
 * @display_srf: surface to be displayed.  The dimension of this will always
 *               match the display mode.  If the display mode matches
 *               content_vfbs dimensions, then this is a pointer into the
 *               corresponding field in content_vfbs.  If not, then this
 *               is a separate buffer to which content_vfbs will blit to.
 * @content_type:  content_fb type
 * @defined:  true if the current display unit has been initialized
 */
struct vmw_screen_target_display_unit {
        struct vmw_display_unit base;
        const struct vmw_surface *display_srf;
        enum stdu_content_type content_fb_type;
        s32 display_width, display_height;

        bool defined;

        /* For CPU Blit */
        unsigned int cpp;
};



static void vmw_stdu_destroy(struct vmw_screen_target_display_unit *stdu);



/******************************************************************************
 * Screen Target Display Unit CRTC Functions
 *****************************************************************************/


/**
 * vmw_stdu_crtc_destroy - cleans up the STDU
 *
 * @crtc: used to get a reference to the containing STDU
 */
static void vmw_stdu_crtc_destroy(struct drm_crtc *crtc)
{
        vmw_stdu_destroy(vmw_crtc_to_stdu(crtc));
}

/**
 * vmw_stdu_define_st - Defines a Screen Target
 *
 * @dev_priv:  VMW DRM device
 * @stdu: display unit to create a Screen Target for
 * @mode: The mode to set.
 * @crtc_x: X coordinate of screen target relative to framebuffer origin.
 * @crtc_y: Y coordinate of screen target relative to framebuffer origin.
 *
 * Creates a STDU that we can used later.  This function is called whenever the
 * framebuffer size changes.
 *
 * RETURNs:
 * 0 on success, error code on failure
 */
static int vmw_stdu_define_st(struct vmw_private *dev_priv,
                              struct vmw_screen_target_display_unit *stdu,
                              struct drm_display_mode *mode,
                              int crtc_x, int crtc_y)
{
        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDefineGBScreenTarget body;
        } *cmd;

        cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

        if (unlikely(cmd == NULL)) {
                DRM_ERROR("Out of FIFO space defining Screen Target\n");
                return -ENOMEM;
        }

        cmd->header.id   = SVGA_3D_CMD_DEFINE_GB_SCREENTARGET;
        cmd->header.size = sizeof(cmd->body);

        cmd->body.stid   = stdu->base.unit;
        cmd->body.width  = mode->hdisplay;
        cmd->body.height = mode->vdisplay;
        cmd->body.flags  = (0 == cmd->body.stid) ? SVGA_STFLAG_PRIMARY : 0;
        cmd->body.dpi    = 0;
        if (stdu->base.is_implicit) {
                cmd->body.xRoot  = crtc_x;
                cmd->body.yRoot  = crtc_y;
        } else {
                cmd->body.xRoot  = stdu->base.gui_x;
                cmd->body.yRoot  = stdu->base.gui_y;
        }
        stdu->base.set_gui_x = cmd->body.xRoot;
        stdu->base.set_gui_y = cmd->body.yRoot;

        vmw_fifo_commit(dev_priv, sizeof(*cmd));

        stdu->defined = true;
        stdu->display_width  = mode->hdisplay;
        stdu->display_height = mode->vdisplay;

        return 0;
}



/**
 * vmw_stdu_bind_st - Binds a surface to a Screen Target
 *
 * @dev_priv: VMW DRM device
 * @stdu: display unit affected
 * @res: Buffer to bind to the screen target.  Set to NULL to blank screen.
 *
 * Binding a surface to a Screen Target the same as flipping
 */
static int vmw_stdu_bind_st(struct vmw_private *dev_priv,
                            struct vmw_screen_target_display_unit *stdu,
                            const struct vmw_resource *res)
{
        SVGA3dSurfaceImageId image;

        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdBindGBScreenTarget body;
        } *cmd;


        if (!stdu->defined) {
                DRM_ERROR("No screen target defined\n");
                return -EINVAL;
        }

        /* Set up image using information in vfb */
        memset(&image, 0, sizeof(image));
        image.sid = res ? res->id : SVGA3D_INVALID_ID;

        cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

        if (unlikely(cmd == NULL)) {
                DRM_ERROR("Out of FIFO space binding a screen target\n");
                return -ENOMEM;
        }

        cmd->header.id   = SVGA_3D_CMD_BIND_GB_SCREENTARGET;
        cmd->header.size = sizeof(cmd->body);

        cmd->body.stid   = stdu->base.unit;
        cmd->body.image  = image;

        vmw_fifo_commit(dev_priv, sizeof(*cmd));

        return 0;
}

/**
 * vmw_stdu_populate_update - populate an UPDATE_GB_SCREENTARGET command with a
 * bounding box.
 *
 * @cmd: Pointer to command stream.
 * @unit: Screen target unit.
 * @left: Left side of bounding box.
 * @right: Right side of bounding box.
 * @top: Top side of bounding box.
 * @bottom: Bottom side of bounding box.
 */
static void vmw_stdu_populate_update(void *cmd, int unit,
                                     s32 left, s32 right, s32 top, s32 bottom)
{
        struct vmw_stdu_update *update = cmd;

        update->header.id   = SVGA_3D_CMD_UPDATE_GB_SCREENTARGET;
        update->header.size = sizeof(update->body);

        update->body.stid   = unit;
        update->body.rect.x = left;
        update->body.rect.y = top;
        update->body.rect.w = right - left;
        update->body.rect.h = bottom - top;
}

/**
 * vmw_stdu_update_st - Full update of a Screen Target
 *
 * @dev_priv: VMW DRM device
 * @stdu: display unit affected
 *
 * This function needs to be called whenever the content of a screen
 * target has changed completely. Typically as a result of a backing
 * surface change.
 *
 * RETURNS:
 * 0 on success, error code on failure
 */
static int vmw_stdu_update_st(struct vmw_private *dev_priv,
                              struct vmw_screen_target_display_unit *stdu)
{
        struct vmw_stdu_update *cmd;

        if (!stdu->defined) {
                DRM_ERROR("No screen target defined");
                return -EINVAL;
        }

        cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

        if (unlikely(cmd == NULL)) {
                DRM_ERROR("Out of FIFO space updating a Screen Target\n");
                return -ENOMEM;
        }

        vmw_stdu_populate_update(cmd, stdu->base.unit,
                                 0, stdu->display_width,
                                 0, stdu->display_height);

        vmw_fifo_commit(dev_priv, sizeof(*cmd));

        return 0;
}



/**
 * vmw_stdu_destroy_st - Destroy a Screen Target
 *
 * @dev_priv:  VMW DRM device
 * @stdu: display unit to destroy
 */
static int vmw_stdu_destroy_st(struct vmw_private *dev_priv,
                               struct vmw_screen_target_display_unit *stdu)
{
        int    ret;

        struct {
                SVGA3dCmdHeader header;
                SVGA3dCmdDestroyGBScreenTarget body;
        } *cmd;


        /* Nothing to do if not successfully defined */
        if (unlikely(!stdu->defined))
                return 0;

        cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

        if (unlikely(cmd == NULL)) {
                DRM_ERROR("Out of FIFO space, screen target not destroyed\n");
                return -ENOMEM;
        }

        cmd->header.id   = SVGA_3D_CMD_DESTROY_GB_SCREENTARGET;
        cmd->header.size = sizeof(cmd->body);

        cmd->body.stid   = stdu->base.unit;

        vmw_fifo_commit(dev_priv, sizeof(*cmd));

        /* Force sync */
        ret = vmw_fallback_wait(dev_priv, false, true, 0, false, 3*HZ);
        if (unlikely(ret != 0))
                DRM_ERROR("Failed to sync with HW");

        stdu->defined = false;
        stdu->display_width  = 0;
        stdu->display_height = 0;

        return ret;
}


/**
 * vmw_stdu_crtc_mode_set_nofb - Updates screen target size
 *
 * @crtc: CRTC associated with the screen target
 *
 * This function defines/destroys a screen target
 *
 */
static void vmw_stdu_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
        struct vmw_private *dev_priv;
        struct vmw_screen_target_display_unit *stdu;
        int ret;


        stdu     = vmw_crtc_to_stdu(crtc);
        dev_priv = vmw_priv(crtc->dev);

        if (stdu->defined) {
                ret = vmw_stdu_bind_st(dev_priv, stdu, NULL);
                if (ret)
                        DRM_ERROR("Failed to blank CRTC\n");

                (void) vmw_stdu_update_st(dev_priv, stdu);

                ret = vmw_stdu_destroy_st(dev_priv, stdu);
                if (ret)
                        DRM_ERROR("Failed to destroy Screen Target\n");

                stdu->content_fb_type = SAME_AS_DISPLAY;
        }

        if (!crtc->state->enable)
                return;

        vmw_svga_enable(dev_priv);
        ret = vmw_stdu_define_st(dev_priv, stdu, &crtc->mode, crtc->x, crtc->y);

        if (ret)
                DRM_ERROR("Failed to define Screen Target of size %dx%d\n",
                          crtc->x, crtc->y);
}


static void vmw_stdu_crtc_helper_prepare(struct drm_crtc *crtc)
{
}


static void vmw_stdu_crtc_atomic_enable(struct drm_crtc *crtc,
                                        struct drm_crtc_state *old_state)
{
        struct vmw_private *dev_priv;
        struct vmw_screen_target_display_unit *stdu;
        struct vmw_framebuffer *vfb;
        struct drm_framebuffer *fb;


        stdu     = vmw_crtc_to_stdu(crtc);
        dev_priv = vmw_priv(crtc->dev);
        fb       = crtc->primary->fb;

        vfb = (fb) ? vmw_framebuffer_to_vfb(fb) : NULL;

        if (vfb)
                vmw_kms_add_active(dev_priv, &stdu->base, vfb);
        else
                vmw_kms_del_active(dev_priv, &stdu->base);
}

static void vmw_stdu_crtc_atomic_disable(struct drm_crtc *crtc,
                                         struct drm_crtc_state *old_state)
{
        struct vmw_private *dev_priv;
        struct vmw_screen_target_display_unit *stdu;
        int ret;


        if (!crtc) {
                DRM_ERROR("CRTC is NULL\n");
                return;
        }

        stdu     = vmw_crtc_to_stdu(crtc);
        dev_priv = vmw_priv(crtc->dev);

        if (stdu->defined) {
                ret = vmw_stdu_bind_st(dev_priv, stdu, NULL);
                if (ret)
                        DRM_ERROR("Failed to blank CRTC\n");

                (void) vmw_stdu_update_st(dev_priv, stdu);

                ret = vmw_stdu_destroy_st(dev_priv, stdu);
                if (ret)
                        DRM_ERROR("Failed to destroy Screen Target\n");

                stdu->content_fb_type = SAME_AS_DISPLAY;
        }
}

/**
 * vmw_stdu_crtc_page_flip - Binds a buffer to a screen target
 *
 * @crtc: CRTC to attach FB to
 * @fb: FB to attach
 * @event: Event to be posted. This event should've been alloced
 *         using k[mz]alloc, and should've been completely initialized.
 * @page_flip_flags: Input flags.
 *
 * If the STDU uses the same display and content buffers, i.e. a true flip,
 * this function will replace the existing display buffer with the new content
 * buffer.
 *
 * If the STDU uses different display and content buffers, i.e. a blit, then
 * only the content buffer will be updated.
 *
 * RETURNS:
 * 0 on success, error code on failure
 */
static int vmw_stdu_crtc_page_flip(struct drm_crtc *crtc,
                                   struct drm_framebuffer *new_fb,
                                   struct drm_pending_vblank_event *event,
                                   uint32_t flags,
                                   struct drm_modeset_acquire_ctx *ctx)

{
        struct vmw_private *dev_priv = vmw_priv(crtc->dev);
        struct vmw_screen_target_display_unit *stdu = vmw_crtc_to_stdu(crtc);
        int ret;

        if (!stdu->defined || !vmw_kms_crtc_flippable(dev_priv, crtc))
                return -EINVAL;

        ret = drm_atomic_helper_page_flip(crtc, new_fb, event, flags, ctx);
        if (ret) {
                DRM_ERROR("Page flip error %d.\n", ret);
                return ret;
        }

        return 0;
}


/**
 * vmw_stdu_dmabuf_clip - Callback to encode a suface DMA command cliprect
 *
 * @dirty: The closure structure.
 *
 * Encodes a surface DMA command cliprect and updates the bounding box
 * for the DMA.
 */
static void vmw_stdu_dmabuf_clip(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *ddirty =
                container_of(dirty, struct vmw_stdu_dirty, base);
        struct vmw_stdu_dma *cmd = dirty->cmd;
        struct SVGA3dCopyBox *blit = (struct SVGA3dCopyBox *) &cmd[1];

        blit += dirty->num_hits;
        blit->srcx = dirty->fb_x;
        blit->srcy = dirty->fb_y;
        blit->x = dirty->unit_x1;
        blit->y = dirty->unit_y1;
        blit->d = 1;
        blit->w = dirty->unit_x2 - dirty->unit_x1;
        blit->h = dirty->unit_y2 - dirty->unit_y1;
        dirty->num_hits++;

        if (ddirty->transfer != SVGA3D_WRITE_HOST_VRAM)
                return;

        /* Destination bounding box */
        ddirty->left = min_t(s32, ddirty->left, dirty->unit_x1);
        ddirty->top = min_t(s32, ddirty->top, dirty->unit_y1);
        ddirty->right = max_t(s32, ddirty->right, dirty->unit_x2);
        ddirty->bottom = max_t(s32, ddirty->bottom, dirty->unit_y2);
}

/**
 * vmw_stdu_dmabuf_fifo_commit - Callback to fill in and submit a DMA command.
 *
 * @dirty: The closure structure.
 *
 * Fills in the missing fields in a DMA command, and optionally encodes
 * a screen target update command, depending on transfer direction.
 */
static void vmw_stdu_dmabuf_fifo_commit(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *ddirty =
                container_of(dirty, struct vmw_stdu_dirty, base);
        struct vmw_screen_target_display_unit *stdu =
                container_of(dirty->unit, typeof(*stdu), base);
        struct vmw_stdu_dma *cmd = dirty->cmd;
        struct SVGA3dCopyBox *blit = (struct SVGA3dCopyBox *) &cmd[1];
        SVGA3dCmdSurfaceDMASuffix *suffix =
                (SVGA3dCmdSurfaceDMASuffix *) &blit[dirty->num_hits];
        size_t blit_size = sizeof(*blit) * dirty->num_hits + sizeof(*suffix);

        if (!dirty->num_hits) {
                vmw_fifo_commit(dirty->dev_priv, 0);
                return;
        }

        cmd->header.id = SVGA_3D_CMD_SURFACE_DMA;
        cmd->header.size = sizeof(cmd->body) + blit_size;
        vmw_bo_get_guest_ptr(&ddirty->buf->base, &cmd->body.guest.ptr);
        cmd->body.guest.pitch = ddirty->pitch;
        cmd->body.host.sid = stdu->display_srf->res.id;
        cmd->body.host.face = 0;
        cmd->body.host.mipmap = 0;
        cmd->body.transfer = ddirty->transfer;
        suffix->suffixSize = sizeof(*suffix);
        suffix->maximumOffset = ddirty->buf->base.num_pages * PAGE_SIZE;

        if (ddirty->transfer == SVGA3D_WRITE_HOST_VRAM) {
                blit_size += sizeof(struct vmw_stdu_update);

                vmw_stdu_populate_update(&suffix[1], stdu->base.unit,
                                         ddirty->left, ddirty->right,
                                         ddirty->top, ddirty->bottom);
        }

        vmw_fifo_commit(dirty->dev_priv, sizeof(*cmd) + blit_size);

        ddirty->left = ddirty->top = S32_MAX;
        ddirty->right = ddirty->bottom = S32_MIN;
}


/**
 * vmw_stdu_dmabuf_cpu_clip - Callback to encode a CPU blit
 *
 * @dirty: The closure structure.
 *
 * This function calculates the bounding box for all the incoming clips.
 */
static void vmw_stdu_dmabuf_cpu_clip(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *ddirty =
                container_of(dirty, struct vmw_stdu_dirty, base);

        dirty->num_hits = 1;

        /* Calculate destination bounding box */
        ddirty->left = min_t(s32, ddirty->left, dirty->unit_x1);
        ddirty->top = min_t(s32, ddirty->top, dirty->unit_y1);
        ddirty->right = max_t(s32, ddirty->right, dirty->unit_x2);
        ddirty->bottom = max_t(s32, ddirty->bottom, dirty->unit_y2);

        /*
         * Calculate content bounding box.  We only need the top-left
         * coordinate because width and height will be the same as the
         * destination bounding box above
         */
        ddirty->fb_left = min_t(s32, ddirty->fb_left, dirty->fb_x);
        ddirty->fb_top  = min_t(s32, ddirty->fb_top, dirty->fb_y);
}


/**
 * vmw_stdu_dmabuf_cpu_commit - Callback to do a CPU blit from DMAbuf
 *
 * @dirty: The closure structure.
 *
 * For the special case when we cannot create a proxy surface in a
 * 2D VM, we have to do a CPU blit ourselves.
 */
static void vmw_stdu_dmabuf_cpu_commit(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *ddirty =
                container_of(dirty, struct vmw_stdu_dirty, base);
        struct vmw_screen_target_display_unit *stdu =
                container_of(dirty->unit, typeof(*stdu), base);
        s32 width, height;
        s32 src_pitch, dst_pitch;
        struct ttm_buffer_object *src_bo, *dst_bo;
        u32 src_offset, dst_offset;
        struct vmw_diff_cpy diff = VMW_CPU_BLIT_DIFF_INITIALIZER(stdu->cpp);

        if (!dirty->num_hits)
                return;

        width = ddirty->right - ddirty->left;
        height = ddirty->bottom - ddirty->top;

        if (width == 0 || height == 0)
                return;

        /* Assume we are blitting from Guest (dmabuf) to Host (display_srf) */
        dst_pitch = stdu->display_srf->base_size.width * stdu->cpp;
        dst_bo = &stdu->display_srf->res.backup->base;
        dst_offset = ddirty->top * dst_pitch + ddirty->left * stdu->cpp;

        src_pitch = ddirty->pitch;
        src_bo = &ddirty->buf->base;
        src_offset = ddirty->fb_top * src_pitch + ddirty->fb_left * stdu->cpp;

        /* Swap src and dst if the assumption was wrong. */
        if (ddirty->transfer != SVGA3D_WRITE_HOST_VRAM) {
                swap(dst_pitch, src_pitch);
                swap(dst_bo, src_bo);
                swap(src_offset, dst_offset);
        }

        (void) vmw_bo_cpu_blit(dst_bo, dst_offset, dst_pitch,
                               src_bo, src_offset, src_pitch,
                               width * stdu->cpp, height, &diff);

        if (ddirty->transfer == SVGA3D_WRITE_HOST_VRAM &&
            drm_rect_visible(&diff.rect)) {
                struct vmw_private *dev_priv;
                struct vmw_stdu_update *cmd;
                struct drm_clip_rect region;
                int ret;

                /* We are updating the actual surface, not a proxy */
                region.x1 = diff.rect.x1;
                region.x2 = diff.rect.x2;
                region.y1 = diff.rect.y1;
                region.y2 = diff.rect.y2;
                ret = vmw_kms_update_proxy(
                        (struct vmw_resource *) &stdu->display_srf->res,
                        (const struct drm_clip_rect *) &region, 1, 1);
                if (ret)
                        goto out_cleanup;


                dev_priv = vmw_priv(stdu->base.crtc.dev);
                cmd = vmw_fifo_reserve(dev_priv, sizeof(*cmd));

                if (!cmd) {
                        DRM_ERROR("Cannot reserve FIFO space to update STDU");
                        goto out_cleanup;
                }

                vmw_stdu_populate_update(cmd, stdu->base.unit,
                                         region.x1, region.x2,
                                         region.y1, region.y2);

                vmw_fifo_commit(dev_priv, sizeof(*cmd));
        }

out_cleanup:
        ddirty->left = ddirty->top = ddirty->fb_left = ddirty->fb_top = S32_MAX;
        ddirty->right = ddirty->bottom = S32_MIN;
}

/**
 * vmw_kms_stdu_dma - Perform a DMA transfer between a dma-buffer backed
 * framebuffer and the screen target system.
 *
 * @dev_priv: Pointer to the device private structure.
 * @file_priv: Pointer to a struct drm-file identifying the caller. May be
 * set to NULL, but then @user_fence_rep must also be set to NULL.
 * @vfb: Pointer to the dma-buffer backed framebuffer.
 * @clips: Array of clip rects. Either @clips or @vclips must be NULL.
 * @vclips: Alternate array of clip rects. Either @clips or @vclips must
 * be NULL.
 * @num_clips: Number of clip rects in @clips or @vclips.
 * @increment: Increment to use when looping over @clips or @vclips.
 * @to_surface: Whether to DMA to the screen target system as opposed to
 * from the screen target system.
 * @interruptible: Whether to perform waits interruptible if possible.
 * @crtc: If crtc is passed, perform stdu dma on that crtc only.
 *
 * If DMA-ing till the screen target system, the function will also notify
 * the screen target system that a bounding box of the cliprects has been
 * updated.
 * Returns 0 on success, negative error code on failure. -ERESTARTSYS if
 * interrupted.
 */
int vmw_kms_stdu_dma(struct vmw_private *dev_priv,
                     struct drm_file *file_priv,
                     struct vmw_framebuffer *vfb,
                     struct drm_vmw_fence_rep __user *user_fence_rep,
                     struct drm_clip_rect *clips,
                     struct drm_vmw_rect *vclips,
                     uint32_t num_clips,
                     int increment,
                     bool to_surface,
                     bool interruptible,
                     struct drm_crtc *crtc)
{
        struct vmw_dma_buffer *buf =
                container_of(vfb, struct vmw_framebuffer_dmabuf, base)->buffer;
        struct vmw_stdu_dirty ddirty;
        int ret;
        bool cpu_blit = !(dev_priv->capabilities & SVGA_CAP_3D);

        /*
         * VMs without 3D support don't have the surface DMA command and
         * we'll be using a CPU blit, and the framebuffer should be moved out
         * of VRAM.
         */
        ret = vmw_kms_helper_buffer_prepare(dev_priv, buf, interruptible,
                                            false, cpu_blit);
        if (ret)
                return ret;

        ddirty.transfer = (to_surface) ? SVGA3D_WRITE_HOST_VRAM :
                SVGA3D_READ_HOST_VRAM;
        ddirty.left = ddirty.top = S32_MAX;
        ddirty.right = ddirty.bottom = S32_MIN;
        ddirty.fb_left = ddirty.fb_top = S32_MAX;
        ddirty.pitch = vfb->base.pitches[0];
        ddirty.buf = buf;
        ddirty.base.fifo_commit = vmw_stdu_dmabuf_fifo_commit;
        ddirty.base.clip = vmw_stdu_dmabuf_clip;
        ddirty.base.fifo_reserve_size = sizeof(struct vmw_stdu_dma) +
                num_clips * sizeof(SVGA3dCopyBox) +
                sizeof(SVGA3dCmdSurfaceDMASuffix);
        if (to_surface)
                ddirty.base.fifo_reserve_size += sizeof(struct vmw_stdu_update);


        if (cpu_blit) {
                ddirty.base.fifo_commit = vmw_stdu_dmabuf_cpu_commit;
                ddirty.base.clip = vmw_stdu_dmabuf_cpu_clip;
                ddirty.base.fifo_reserve_size = 0;
        }

        ddirty.base.crtc = crtc;

        ret = vmw_kms_helper_dirty(dev_priv, vfb, clips, vclips,
                                   0, 0, num_clips, increment, &ddirty.base);
        vmw_kms_helper_buffer_finish(dev_priv, file_priv, buf, NULL,
                                     user_fence_rep);

        return ret;
}

/**
 * vmw_stdu_surface_clip - Callback to encode a surface copy command cliprect
 *
 * @dirty: The closure structure.
 *
 * Encodes a surface copy command cliprect and updates the bounding box
 * for the copy.
 */
static void vmw_kms_stdu_surface_clip(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *sdirty =
                container_of(dirty, struct vmw_stdu_dirty, base);
        struct vmw_stdu_surface_copy *cmd = dirty->cmd;
        struct vmw_screen_target_display_unit *stdu =
                container_of(dirty->unit, typeof(*stdu), base);

        if (sdirty->sid != stdu->display_srf->res.id) {
                struct SVGA3dCopyBox *blit = (struct SVGA3dCopyBox *) &cmd[1];

                blit += dirty->num_hits;
                blit->srcx = dirty->fb_x;
                blit->srcy = dirty->fb_y;
                blit->x = dirty->unit_x1;
                blit->y = dirty->unit_y1;
                blit->d = 1;
                blit->w = dirty->unit_x2 - dirty->unit_x1;
                blit->h = dirty->unit_y2 - dirty->unit_y1;
        }

        dirty->num_hits++;

        /* Destination bounding box */
        sdirty->left = min_t(s32, sdirty->left, dirty->unit_x1);
        sdirty->top = min_t(s32, sdirty->top, dirty->unit_y1);
        sdirty->right = max_t(s32, sdirty->right, dirty->unit_x2);
        sdirty->bottom = max_t(s32, sdirty->bottom, dirty->unit_y2);
}

/**
 * vmw_stdu_surface_fifo_commit - Callback to fill in and submit a surface
 * copy command.
 *
 * @dirty: The closure structure.
 *
 * Fills in the missing fields in a surface copy command, and encodes a screen
 * target update command.
 */
static void vmw_kms_stdu_surface_fifo_commit(struct vmw_kms_dirty *dirty)
{
        struct vmw_stdu_dirty *sdirty =
                container_of(dirty, struct vmw_stdu_dirty, base);
        struct vmw_screen_target_display_unit *stdu =
                container_of(dirty->unit, typeof(*stdu), base);
        struct vmw_stdu_surface_copy *cmd = dirty->cmd;
        struct vmw_stdu_update *update;
        size_t blit_size = sizeof(SVGA3dCopyBox) * dirty->num_hits;
        size_t commit_size;

        if (!dirty->num_hits) {
                vmw_fifo_commit(dirty->dev_priv, 0);
                return;
        }

        if (sdirty->sid != stdu->display_srf->res.id) {
                struct SVGA3dCopyBox *blit = (struct SVGA3dCopyBox *) &cmd[1];

                cmd->header.id = SVGA_3D_CMD_SURFACE_COPY;
                cmd->header.size = sizeof(cmd->body) + blit_size;
                cmd->body.src.sid = sdirty->sid;
                cmd->body.dest.sid = stdu->display_srf->res.id;
                update = (struct vmw_stdu_update *) &blit[dirty->num_hits];
                commit_size = sizeof(*cmd) + blit_size + sizeof(*update);
        } else {
                update = dirty->cmd;
                commit_size = sizeof(*update);
        }

        vmw_stdu_populate_update(update, stdu->base.unit, sdirty->left,
                                 sdirty->right, sdirty->top, sdirty->bottom);

        vmw_fifo_commit(dirty->dev_priv, commit_size);

        sdirty->left = sdirty->top = S32_MAX;
        sdirty->right = sdirty->bottom = S32_MIN;
}

/**
 * vmw_kms_stdu_surface_dirty - Dirty part of a surface backed framebuffer
 *
 * @dev_priv: Pointer to the device private structure.
 * @framebuffer: Pointer to the surface-buffer backed framebuffer.
 * @clips: Array of clip rects. Either @clips or @vclips must be NULL.
 * @vclips: Alternate array of clip rects. Either @clips or @vclips must
 * be NULL.
 * @srf: Pointer to surface to blit from. If NULL, the surface attached
 * to @framebuffer will be used.
 * @dest_x: X coordinate offset to align @srf with framebuffer coordinates.
 * @dest_y: Y coordinate offset to align @srf with framebuffer coordinates.
 * @num_clips: Number of clip rects in @clips.
 * @inc: Increment to use when looping over @clips.
 * @out_fence: If non-NULL, will return a ref-counted pointer to a
 * struct vmw_fence_obj. The returned fence pointer may be NULL in which
 * case the device has already synchronized.
 * @crtc: If crtc is passed, perform surface dirty on that crtc only.
 *
 * Returns 0 on success, negative error code on failure. -ERESTARTSYS if
 * interrupted.
 */
int vmw_kms_stdu_surface_dirty(struct vmw_private *dev_priv,
                               struct vmw_framebuffer *framebuffer,
                               struct drm_clip_rect *clips,
                               struct drm_vmw_rect *vclips,
                               struct vmw_resource *srf,
                               s32 dest_x,
                               s32 dest_y,
                               unsigned num_clips, int inc,
                               struct vmw_fence_obj **out_fence,
                               struct drm_crtc *crtc)
{
        struct vmw_framebuffer_surface *vfbs =
                container_of(framebuffer, typeof(*vfbs), base);
        struct vmw_stdu_dirty sdirty;
        struct vmw_validation_ctx ctx;
        int ret;

        if (!srf)
                srf = &vfbs->surface->res;

        ret = vmw_kms_helper_resource_prepare(srf, true, &ctx);
        if (ret)
                return ret;

        if (vfbs->is_dmabuf_proxy) {
                ret = vmw_kms_update_proxy(srf, clips, num_clips, inc);
                if (ret)
                        goto out_finish;
        }

        sdirty.base.fifo_commit = vmw_kms_stdu_surface_fifo_commit;
        sdirty.base.clip = vmw_kms_stdu_surface_clip;
        sdirty.base.fifo_reserve_size = sizeof(struct vmw_stdu_surface_copy) +
                sizeof(SVGA3dCopyBox) * num_clips +
                sizeof(struct vmw_stdu_update);
        sdirty.base.crtc = crtc;
        sdirty.sid = srf->id;
        sdirty.left = sdirty.top = S32_MAX;
        sdirty.right = sdirty.bottom = S32_MIN;

        ret = vmw_kms_helper_dirty(dev_priv, framebuffer, clips, vclips,
                                   dest_x, dest_y, num_clips, inc,
                                   &sdirty.base);
out_finish:
        vmw_kms_helper_resource_finish(&ctx, out_fence);

        return ret;
}


/*
 *  Screen Target CRTC dispatch table
 */
static const struct drm_crtc_funcs vmw_stdu_crtc_funcs = {
        .gamma_set = vmw_du_crtc_gamma_set,
        .destroy = vmw_stdu_crtc_destroy,
        .reset = vmw_du_crtc_reset,
        .atomic_duplicate_state = vmw_du_crtc_duplicate_state,
        .atomic_destroy_state = vmw_du_crtc_destroy_state,
        .set_config = vmw_kms_set_config,
        .page_flip = vmw_stdu_crtc_page_flip,
};



/******************************************************************************
 * Screen Target Display Unit Encoder Functions
 *****************************************************************************/

/**
 * vmw_stdu_encoder_destroy - cleans up the STDU
 *
 * @encoder: used the get the containing STDU
 *
 * vmwgfx cleans up crtc/encoder/connector all at the same time so technically
 * this can be a no-op.  Nevertheless, it doesn't hurt of have this in case
 * the common KMS code changes and somehow vmw_stdu_crtc_destroy() doesn't
 * get called.
 */
static void vmw_stdu_encoder_destroy(struct drm_encoder *encoder)
{
        vmw_stdu_destroy(vmw_encoder_to_stdu(encoder));
}

static const struct drm_encoder_funcs vmw_stdu_encoder_funcs = {
        .destroy = vmw_stdu_encoder_destroy,
};



/******************************************************************************
 * Screen Target Display Unit Connector Functions
 *****************************************************************************/

/**
 * vmw_stdu_connector_destroy - cleans up the STDU

 *
 * @connector: used to get the containing STDU
 *
 * vmwgfx cleans up crtc/encoder/connector all at the same time so technically
 * this can be a no-op.  Nevertheless, it doesn't hurt of have this in case
 * the common KMS code changes and somehow vmw_stdu_crtc_destroy() doesn't
 * get called.
 */
static void vmw_stdu_connector_destroy(struct drm_connector *connector)
{
        vmw_stdu_destroy(vmw_connector_to_stdu(connector));
}



static const struct drm_connector_funcs vmw_stdu_connector_funcs = {
        .dpms = vmw_du_connector_dpms,
        .detect = vmw_du_connector_detect,
        .fill_modes = vmw_du_connector_fill_modes,
        .set_property = vmw_du_connector_set_property,
        .destroy = vmw_stdu_connector_destroy,
        .reset = vmw_du_connector_reset,
        .atomic_duplicate_state = vmw_du_connector_duplicate_state,
        .atomic_destroy_state = vmw_du_connector_destroy_state,
        .atomic_set_property = vmw_du_connector_atomic_set_property,
        .atomic_get_property = vmw_du_connector_atomic_get_property,
};


static const struct
drm_connector_helper_funcs vmw_stdu_connector_helper_funcs = {
        .best_encoder = drm_atomic_helper_best_encoder,
};



/******************************************************************************
 * Screen Target Display Plane Functions
 *****************************************************************************/



/**
 * vmw_stdu_primary_plane_cleanup_fb - Unpins the display surface
 *
 * @plane:  display plane
 * @old_state: Contains the FB to clean up
 *
 * Unpins the display surface
 *
 * Returns 0 on success
 */
static void
vmw_stdu_primary_plane_cleanup_fb(struct drm_plane *plane,
                                  struct drm_plane_state *old_state)
{
        struct vmw_plane_state *vps = vmw_plane_state_to_vps(old_state);

        if (vps->surf)
                WARN_ON(!vps->pinned);

        vmw_du_plane_cleanup_fb(plane, old_state);

        vps->content_fb_type = SAME_AS_DISPLAY;
        vps->cpp = 0;
}



/**
 * vmw_stdu_primary_plane_prepare_fb - Readies the display surface
 *
 * @plane:  display plane
 * @new_state: info on the new plane state, including the FB
 *
 * This function allocates a new display surface if the content is
 * backed by a DMA.  The display surface is pinned here, and it'll
 * be unpinned in .cleanup_fb()
 *
 * Returns 0 on success
 */
static int
vmw_stdu_primary_plane_prepare_fb(struct drm_plane *plane,
                                  struct drm_plane_state *new_state)
{
        struct vmw_private *dev_priv = vmw_priv(plane->dev);
        struct drm_framebuffer *new_fb = new_state->fb;
        struct vmw_framebuffer *vfb;
        struct vmw_plane_state *vps = vmw_plane_state_to_vps(new_state);
        enum stdu_content_type new_content_type;
        struct vmw_framebuffer_surface *new_vfbs;
        struct drm_crtc *crtc = new_state->crtc;
        uint32_t hdisplay = new_state->crtc_w, vdisplay = new_state->crtc_h;
        int ret;

        /* No FB to prepare */
        if (!new_fb) {
                if (vps->surf) {
                        WARN_ON(vps->pinned != 0);
                        vmw_surface_unreference(&vps->surf);
                }

                return 0;
        }

        vfb = vmw_framebuffer_to_vfb(new_fb);
        new_vfbs = (vfb->dmabuf) ? NULL : vmw_framebuffer_to_vfbs(new_fb);

        if (new_vfbs && new_vfbs->surface->base_size.width == hdisplay &&
            new_vfbs->surface->base_size.height == vdisplay)
                new_content_type = SAME_AS_DISPLAY;
        else if (vfb->dmabuf)
                new_content_type = SEPARATE_DMA;
        else
                new_content_type = SEPARATE_SURFACE;

        if (new_content_type != SAME_AS_DISPLAY) {
                struct vmw_surface content_srf;
                struct drm_vmw_size display_base_size = {0};

                display_base_size.width  = hdisplay;
                display_base_size.height = vdisplay;
                display_base_size.depth  = 1;

                /*
                 * If content buffer is a DMA buf, then we have to construct
                 * surface info
                 */
                if (new_content_type == SEPARATE_DMA) {

                        switch (new_fb->format->cpp[0]*8) {
                        case 32:
                                content_srf.format = SVGA3D_X8R8G8B8;
                                break;

                        case 16:
                                content_srf.format = SVGA3D_R5G6B5;
                                break;

                        case 8:
                                content_srf.format = SVGA3D_P8;
                                break;

                        default:
                                DRM_ERROR("Invalid format\n");
                                return -EINVAL;
                        }

                        content_srf.flags             = 0;
                        content_srf.mip_levels[0]     = 1;
                        content_srf.multisample_count = 0;
                } else {
                        content_srf = *new_vfbs->surface;
                }

                if (vps->surf) {
                        struct drm_vmw_size cur_base_size = vps->surf->base_size;

                        if (cur_base_size.width != display_base_size.width ||
                            cur_base_size.height != display_base_size.height ||
                            vps->surf->format != content_srf.format) {
                                WARN_ON(vps->pinned != 0);
                                vmw_surface_unreference(&vps->surf);
                        }

                }

                if (!vps->surf) {
                        ret = vmw_surface_gb_priv_define
                                (crtc->dev,
                                 /* Kernel visible only */
                                 0,
                                 content_srf.flags,
                                 content_srf.format,
                                 true,  /* a scanout buffer */
                                 content_srf.mip_levels[0],
                                 content_srf.multisample_count,
                                 0,
                                 display_base_size,
                                 &vps->surf);
                        if (ret != 0) {
                                DRM_ERROR("Couldn't allocate STDU surface.\n");
                                return ret;
                        }
                }
        } else {
                /*
                 * prepare_fb and clean_fb should only take care of pinning
                 * and unpinning.  References are tracked by state objects.
                 * The only time we add a reference in prepare_fb is if the
                 * state object doesn't have a reference to begin with
                 */
                if (vps->surf) {
                        WARN_ON(vps->pinned != 0);
                        vmw_surface_unreference(&vps->surf);
                }

                vps->surf = vmw_surface_reference(new_vfbs->surface);
        }

        if (vps->surf) {

                /* Pin new surface before flipping */
                ret = vmw_resource_pin(&vps->surf->res, false);
                if (ret)
                        goto out_srf_unref;

                vps->pinned++;
        }

        vps->content_fb_type = new_content_type;

        /*
         * This should only happen if the DMA buf is too large to create a
         * proxy surface for.
         * If we are a 2D VM with a DMA buffer then we have to use CPU blit
         * so cache these mappings
         */
        if (vps->content_fb_type == SEPARATE_DMA &&
            !(dev_priv->capabilities & SVGA_CAP_3D))
                vps->cpp = new_fb->pitches[0] / new_fb->width;

        return 0;

out_srf_unref:
        vmw_surface_unreference(&vps->surf);
        return ret;
}



/**
 * vmw_stdu_primary_plane_atomic_update - formally switches STDU to new plane
 *
 * @plane: display plane
 * @old_state: Only used to get crtc info
 *
 * Formally update stdu->display_srf to the new plane, and bind the new
 * plane STDU.  This function is called during the commit phase when
 * all the preparation have been done and all the configurations have
 * been checked.
 */
static void
vmw_stdu_primary_plane_atomic_update(struct drm_plane *plane,
                                     struct drm_plane_state *old_state)
{
        struct vmw_plane_state *vps = vmw_plane_state_to_vps(plane->state);
        struct drm_crtc *crtc = plane->state->crtc;
        struct vmw_screen_target_display_unit *stdu;
        struct drm_pending_vblank_event *event;
        struct vmw_private *dev_priv;
        int ret;

        /*
         * We cannot really fail this function, so if we do, then output an
         * error and maintain consistent atomic state.
         */
        if (crtc && plane->state->fb) {
                struct vmw_framebuffer *vfb =
                        vmw_framebuffer_to_vfb(plane->state->fb);
                struct drm_vmw_rect vclips;
                stdu = vmw_crtc_to_stdu(crtc);
                dev_priv = vmw_priv(crtc->dev);

                stdu->display_srf = vps->surf;
                stdu->content_fb_type = vps->content_fb_type;
                stdu->cpp = vps->cpp;

                vclips.x = crtc->x;
                vclips.y = crtc->y;
                vclips.w = crtc->mode.hdisplay;
                vclips.h = crtc->mode.vdisplay;

                ret = vmw_stdu_bind_st(dev_priv, stdu, &stdu->display_srf->res);
                if (ret)
                        DRM_ERROR("Failed to bind surface to STDU.\n");

                if (vfb->dmabuf)
                        ret = vmw_kms_stdu_dma(dev_priv, NULL, vfb, NULL, NULL,
                                               &vclips, 1, 1, true, false,
                                               crtc);
                else
                        ret = vmw_kms_stdu_surface_dirty(dev_priv, vfb, NULL,
                                                         &vclips, NULL, 0, 0,
                                                         1, 1, NULL, crtc);
                if (ret)
                        DRM_ERROR("Failed to update STDU.\n");

                crtc->primary->fb = plane->state->fb;
        } else {
                crtc = old_state->crtc;
                stdu = vmw_crtc_to_stdu(crtc);
                dev_priv = vmw_priv(crtc->dev);

                /*
                 * When disabling a plane, CRTC and FB should always be NULL
                 * together, otherwise it's an error.
                 * Here primary plane is being disable so blank the screen
                 * target display unit, if not already done.
                 */
                if (!stdu->defined)
                        return;

                ret = vmw_stdu_bind_st(dev_priv, stdu, NULL);
                if (ret)
                        DRM_ERROR("Failed to blank STDU\n");

                ret = vmw_stdu_update_st(dev_priv, stdu);
                if (ret)
                        DRM_ERROR("Failed to update STDU.\n");

                return;
        }

        event = crtc->state->event;
        /*
         * In case of failure and other cases, vblank event will be sent in
         * vmw_du_crtc_atomic_flush.
         */
        if (event && (ret == 0)) {
                struct vmw_fence_obj *fence = NULL;
                struct drm_file *file_priv = event->base.file_priv;

                vmw_execbuf_fence_commands(NULL, dev_priv, &fence, NULL);

                /*
                 * If fence is NULL, then already sync.
                 */
                if (fence) {
                        ret = vmw_event_fence_action_queue(
                                file_priv, fence, &event->base,
                                &event->event.vbl.tv_sec,
                                &event->event.vbl.tv_usec,
                                true);
                        if (ret)
                                DRM_ERROR("Failed to queue event on fence.\n");
                        else
                                crtc->state->event = NULL;

                        vmw_fence_obj_unreference(&fence);
                }
        } else {
                (void) vmw_fifo_flush(dev_priv, false);
        }
}


static const struct drm_plane_funcs vmw_stdu_plane_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = vmw_du_primary_plane_destroy,
        .reset = vmw_du_plane_reset,
        .atomic_duplicate_state = vmw_du_plane_duplicate_state,
        .atomic_destroy_state = vmw_du_plane_destroy_state,
};

static const struct drm_plane_funcs vmw_stdu_cursor_funcs = {
        .update_plane = drm_atomic_helper_update_plane,
        .disable_plane = drm_atomic_helper_disable_plane,
        .destroy = vmw_du_cursor_plane_destroy,
        .reset = vmw_du_plane_reset,
        .atomic_duplicate_state = vmw_du_plane_duplicate_state,
        .atomic_destroy_state = vmw_du_plane_destroy_state,
};


/*
 * Atomic Helpers
 */
static const struct
drm_plane_helper_funcs vmw_stdu_cursor_plane_helper_funcs = {
        .atomic_check = vmw_du_cursor_plane_atomic_check,
        .atomic_update = vmw_du_cursor_plane_atomic_update,
        .prepare_fb = vmw_du_cursor_plane_prepare_fb,
        .cleanup_fb = vmw_du_plane_cleanup_fb,
};

static const struct
drm_plane_helper_funcs vmw_stdu_primary_plane_helper_funcs = {
        .atomic_check = vmw_du_primary_plane_atomic_check,
        .atomic_update = vmw_stdu_primary_plane_atomic_update,
        .prepare_fb = vmw_stdu_primary_plane_prepare_fb,
        .cleanup_fb = vmw_stdu_primary_plane_cleanup_fb,
};

static const struct drm_crtc_helper_funcs vmw_stdu_crtc_helper_funcs = {
        .prepare = vmw_stdu_crtc_helper_prepare,
        .mode_set_nofb = vmw_stdu_crtc_mode_set_nofb,
        .atomic_check = vmw_du_crtc_atomic_check,
        .atomic_begin = vmw_du_crtc_atomic_begin,
        .atomic_flush = vmw_du_crtc_atomic_flush,
        .atomic_enable = vmw_stdu_crtc_atomic_enable,
        .atomic_disable = vmw_stdu_crtc_atomic_disable,
};


/**
 * vmw_stdu_init - Sets up a Screen Target Display Unit
 *
 * @dev_priv: VMW DRM device
 * @unit: unit number range from 0 to VMWGFX_NUM_DISPLAY_UNITS
 *
 * This function is called once per CRTC, and allocates one Screen Target
 * display unit to represent that CRTC.  Since the SVGA device does not separate
 * out encoder and connector, they are represented as part of the STDU as well.
 */
static int vmw_stdu_init(struct vmw_private *dev_priv, unsigned unit)
{
        struct vmw_screen_target_display_unit *stdu;
        struct drm_device *dev = dev_priv->dev;
        struct drm_connector *connector;
        struct drm_encoder *encoder;
        struct drm_plane *primary, *cursor;
        struct drm_crtc *crtc;
        int    ret;


        stdu = kzalloc(sizeof(*stdu), GFP_KERNEL);
        if (!stdu)
                return -ENOMEM;

        stdu->base.unit = unit;
        crtc = &stdu->base.crtc;
        encoder = &stdu->base.encoder;
        connector = &stdu->base.connector;
        primary = &stdu->base.primary;
        cursor = &stdu->base.cursor;

        stdu->base.pref_active = (unit == 0);
        stdu->base.pref_width  = dev_priv->initial_width;
        stdu->base.pref_height = dev_priv->initial_height;

        /*
         * Remove this after enabling atomic because property values can
         * only exist in a state object
         */
        stdu->base.is_implicit = false;

        /* Initialize primary plane */
        vmw_du_plane_reset(primary);

        ret = drm_universal_plane_init(dev, primary,
                                       0, &vmw_stdu_plane_funcs,
                                       vmw_primary_plane_formats,
                                       ARRAY_SIZE(vmw_primary_plane_formats),
                                       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
        if (ret) {
                DRM_ERROR("Failed to initialize primary plane");
                goto err_free;
        }

        drm_plane_helper_add(primary, &vmw_stdu_primary_plane_helper_funcs);

        /* Initialize cursor plane */
        vmw_du_plane_reset(cursor);

        ret = drm_universal_plane_init(dev, cursor,
                        0, &vmw_stdu_cursor_funcs,
                        vmw_cursor_plane_formats,
                        ARRAY_SIZE(vmw_cursor_plane_formats),
                        NULL, DRM_PLANE_TYPE_CURSOR, NULL);
        if (ret) {
                DRM_ERROR("Failed to initialize cursor plane");
                drm_plane_cleanup(&stdu->base.primary);
                goto err_free;
        }

        drm_plane_helper_add(cursor, &vmw_stdu_cursor_plane_helper_funcs);

        vmw_du_connector_reset(connector);

        ret = drm_connector_init(dev, connector, &vmw_stdu_connector_funcs,
                                 DRM_MODE_CONNECTOR_VIRTUAL);
        if (ret) {
                DRM_ERROR("Failed to initialize connector\n");
                goto err_free;
        }

        drm_connector_helper_add(connector, &vmw_stdu_connector_helper_funcs);
        connector->status = vmw_du_connector_detect(connector, false);
        vmw_connector_state_to_vcs(connector->state)->is_implicit = false;

        ret = drm_encoder_init(dev, encoder, &vmw_stdu_encoder_funcs,
                               DRM_MODE_ENCODER_VIRTUAL, NULL);
        if (ret) {
                DRM_ERROR("Failed to initialize encoder\n");
                goto err_free_connector;
        }

        (void) drm_mode_connector_attach_encoder(connector, encoder);
        encoder->possible_crtcs = (1 << unit);
        encoder->possible_clones = 0;

        ret = drm_connector_register(connector);
        if (ret) {
                DRM_ERROR("Failed to register connector\n");
                goto err_free_encoder;
        }

        vmw_du_crtc_reset(crtc);
        ret = drm_crtc_init_with_planes(dev, crtc, &stdu->base.primary,
                                        &stdu->base.cursor,
                                        &vmw_stdu_crtc_funcs, NULL);
        if (ret) {
                DRM_ERROR("Failed to initialize CRTC\n");
                goto err_free_unregister;
        }

        drm_crtc_helper_add(crtc, &vmw_stdu_crtc_helper_funcs);

        drm_mode_crtc_set_gamma_size(crtc, 256);

        drm_object_attach_property(&connector->base,
                                   dev_priv->hotplug_mode_update_property, 1);
        drm_object_attach_property(&connector->base,
                                   dev->mode_config.suggested_x_property, 0);
        drm_object_attach_property(&connector->base,
                                   dev->mode_config.suggested_y_property, 0);
        if (dev_priv->implicit_placement_property)
                drm_object_attach_property
                        (&connector->base,
                         dev_priv->implicit_placement_property,
                         stdu->base.is_implicit);
        return 0;

err_free_unregister:
        drm_connector_unregister(connector);
err_free_encoder:
        drm_encoder_cleanup(encoder);
err_free_connector:
        drm_connector_cleanup(connector);
err_free:
        kfree(stdu);
        return ret;
}



/**
 *  vmw_stdu_destroy - Cleans up a vmw_screen_target_display_unit
 *
 *  @stdu:  Screen Target Display Unit to be destroyed
 *
 *  Clean up after vmw_stdu_init
 */
static void vmw_stdu_destroy(struct vmw_screen_target_display_unit *stdu)
{
        vmw_du_cleanup(&stdu->base);
        kfree(stdu);
}



/******************************************************************************
 * Screen Target Display KMS Functions
 *
 * These functions are called by the common KMS code in vmwgfx_kms.c
 *****************************************************************************/

/**
 * vmw_kms_stdu_init_display - Initializes a Screen Target based display
 *
 * @dev_priv: VMW DRM device
 *
 * This function initialize a Screen Target based display device.  It checks
 * the capability bits to make sure the underlying hardware can support
 * screen targets, and then creates the maximum number of CRTCs, a.k.a Display
 * Units, as supported by the display hardware.
 *
 * RETURNS:
 * 0 on success, error code otherwise
 */
int vmw_kms_stdu_init_display(struct vmw_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        int i, ret;


        /* Do nothing if Screen Target support is turned off */
        if (!VMWGFX_ENABLE_SCREEN_TARGET_OTABLE)
                return -ENOSYS;

        if (!(dev_priv->capabilities & SVGA_CAP_GBOBJECTS))
                return -ENOSYS;

        ret = drm_vblank_init(dev, VMWGFX_NUM_DISPLAY_UNITS);
        if (unlikely(ret != 0))
                return ret;

        dev_priv->active_display_unit = vmw_du_screen_target;

        if (dev_priv->capabilities & SVGA_CAP_3D) {
                /*
                 * For 3D VMs, display (scanout) buffer size is the smaller of
                 * max texture and max STDU
                 */
                uint32_t max_width, max_height;

                max_width = min(dev_priv->texture_max_width,
                                dev_priv->stdu_max_width);
                max_height = min(dev_priv->texture_max_height,
                                 dev_priv->stdu_max_height);

                dev->mode_config.max_width = max_width;
                dev->mode_config.max_height = max_height;
        } else {
                /*
                 * Given various display aspect ratios, there's no way to
                 * estimate these using prim_bb_mem.  So just set these to
                 * something arbitrarily large and we will reject any layout
                 * that doesn't fit prim_bb_mem later
                 */
                dev->mode_config.max_width = 8192;
                dev->mode_config.max_height = 8192;
        }

        vmw_kms_create_implicit_placement_property(dev_priv, false);

        for (i = 0; i < VMWGFX_NUM_DISPLAY_UNITS; ++i) {
                ret = vmw_stdu_init(dev_priv, i);

                if (unlikely(ret != 0)) {
                        DRM_ERROR("Failed to initialize STDU %d", i);
                        return ret;
                }
        }

        DRM_INFO("Screen Target Display device initialized\n");

        return 0;
}