DRMFILE filp;           /* 0: free, -1: heap, other: real files */
 };
 
+typedef struct _drm_i915_vbl_swap {
+       struct list_head head;
+       drm_drawable_t drw_id;
+       unsigned int pipe;
+       unsigned int sequence;
+} drm_i915_vbl_swap_t;
+
 typedef struct drm_i915_private {
        drm_local_map_t *sarea;
        drm_local_map_t *mmio_map;
        dma_addr_t dma_status_page;
        unsigned long counter;
 
+       unsigned int cpp;
        int back_offset;
        int front_offset;
        int current_page;
        struct mem_block *agp_heap;
        unsigned int sr01, adpa, ppcr, dvob, dvoc, lvds;
        int vblank_pipe;
+
+       spinlock_t swaps_lock;
+       drm_i915_vbl_swap_t vbl_swaps;
+       unsigned int swaps_pending;
 } drm_i915_private_t;
 
 extern drm_ioctl_desc_t i915_ioctls[];
 extern void i915_driver_irq_uninstall(drm_device_t * dev);
 extern int i915_vblank_pipe_set(DRM_IOCTL_ARGS);
 extern int i915_vblank_pipe_get(DRM_IOCTL_ARGS);
+extern int i915_vblank_swap(DRM_IOCTL_ARGS);
 
 /* i915_mem.c */
 extern int i915_mem_alloc(DRM_IOCTL_ARGS);
 
 #define GFX_OP_DRAWRECT_INFO_I965 ((0x7900<<16)|0x2)
 
+#define XY_SRC_COPY_BLT_CMD            ((2<<29)|(0x53<<22)|6)
+#define XY_SRC_COPY_BLT_WRITE_ALPHA    (1<<21)
+#define XY_SRC_COPY_BLT_WRITE_RGB      (1<<20)
+
 #define MI_BATCH_BUFFER        ((0x30<<23)|1)
 #define MI_BATCH_BUFFER_START  (0x31<<23)
 #define MI_BATCH_BUFFER_END    (0xA<<23)
 
 
 #define MAX_NOPID ((u32)~0)
 
+/**
+ * Emit blits for scheduled buffer swaps.
+ *
+ * This function will be called with the HW lock held.
+ */
+static void i915_vblank_tasklet(drm_device_t *dev)
+{
+       drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+       unsigned int irqflags;
+       struct list_head *list, *tmp;
+
+       DRM_DEBUG("\n");
+
+       spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+       list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
+               drm_i915_vbl_swap_t *vbl_swap =
+                       list_entry(list, drm_i915_vbl_swap_t, head);
+               atomic_t *counter = vbl_swap->pipe ? &dev->vbl_received2 :
+                       &dev->vbl_received;
+
+               if ((atomic_read(counter) - vbl_swap->sequence) <= (1<<23)) {
+                       drm_drawable_info_t *drw;
+
+                       spin_unlock(&dev_priv->swaps_lock);
+
+                       spin_lock(&dev->drw_lock);
+
+                       drw = drm_get_drawable_info(dev, vbl_swap->drw_id);
+                               
+                       if (drw) {
+                               int i, num_rects = drw->num_rects;
+                               drm_clip_rect_t *rect = drw->rects;
+                               drm_i915_sarea_t *sarea_priv =
+                                   dev_priv->sarea_priv;
+                               u32 cpp = dev_priv->cpp;
+                               u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
+                                                       XY_SRC_COPY_BLT_WRITE_ALPHA |
+                                                       XY_SRC_COPY_BLT_WRITE_RGB)
+                                                    : XY_SRC_COPY_BLT_CMD;
+                               u32 pitchropcpp = (sarea_priv->pitch * cpp) |
+                                                 (0xcc << 16) | (cpp << 23) |
+                                                 (1 << 24);
+                               RING_LOCALS;
+
+                               i915_kernel_lost_context(dev);
+
+                               BEGIN_LP_RING(6);
+
+                               OUT_RING(GFX_OP_DRAWRECT_INFO);
+                               OUT_RING(0);
+                               OUT_RING(0);
+                               OUT_RING(sarea_priv->width |
+                                        sarea_priv->height << 16);
+                               OUT_RING(sarea_priv->width |
+                                        sarea_priv->height << 16);
+                               OUT_RING(0);
+
+                               ADVANCE_LP_RING();
+
+                               sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;
+
+                               for (i = 0; i < num_rects; i++, rect++) {
+                                       BEGIN_LP_RING(8);
+
+                                       OUT_RING(cmd);
+                                       OUT_RING(pitchropcpp);
+                                       OUT_RING((rect->y1 << 16) | rect->x1);
+                                       OUT_RING((rect->y2 << 16) | rect->x2);
+                                       OUT_RING(sarea_priv->front_offset);
+                                       OUT_RING((rect->y1 << 16) | rect->x1);
+                                       OUT_RING(pitchropcpp & 0xffff);
+                                       OUT_RING(sarea_priv->back_offset);
+
+                                       ADVANCE_LP_RING();
+                               }
+                       }
+
+                       spin_unlock(&dev->drw_lock);
+
+                       spin_lock(&dev_priv->swaps_lock);
+
+                       list_del(list);
+
+                       drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
+
+                       dev_priv->swaps_pending--;
+               }
+       }
+
+       spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+}
+
 irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 {
        drm_device_t *dev = (drm_device_t *) arg;
 
                DRM_WAKEUP(&dev->vbl_queue);
                drm_vbl_send_signals(dev);
+
+               drm_locked_tasklet(dev, i915_vblank_tasklet);
        }
 
        return IRQ_HANDLED;
        return 0;
 }
 
+/**
+ * Schedule buffer swap at given vertical blank.
+ */
+int i915_vblank_swap(DRM_IOCTL_ARGS)
+{
+       DRM_DEVICE;
+       drm_i915_private_t *dev_priv = dev->dev_private;
+       drm_i915_vblank_swap_t swap;
+       drm_i915_vbl_swap_t *vbl_swap;
+       unsigned int irqflags;
+       struct list_head *list;
+
+       if (!dev_priv) {
+               DRM_ERROR("%s called with no initialization\n", __func__);
+               return DRM_ERR(EINVAL);
+       }
+
+       if (dev_priv->sarea_priv->rotation) {
+               DRM_DEBUG("Rotation not supported\n");
+               return DRM_ERR(EINVAL);
+       }
+
+       if (dev_priv->swaps_pending >= 100) {
+               DRM_DEBUG("Too many swaps queued\n");
+               return DRM_ERR(EBUSY);
+       }
+
+       DRM_COPY_FROM_USER_IOCTL(swap, (drm_i915_vblank_swap_t __user *) data,
+                                sizeof(swap));
+
+       if (swap.pipe > 1 || !(dev_priv->vblank_pipe & (1 << swap.pipe))) {
+               DRM_ERROR("Invalid pipe %d\n", swap.pipe);
+               return DRM_ERR(EINVAL);
+       }
+
+       spin_lock_irqsave(&dev->drw_lock, irqflags);
+
+       if (!drm_get_drawable_info(dev, swap.drawable)) {
+               spin_unlock_irqrestore(&dev->drw_lock, irqflags);
+               DRM_ERROR("Invalid drawable ID %d\n", swap.drawable);
+               return DRM_ERR(EINVAL);
+       }
+
+       spin_unlock_irqrestore(&dev->drw_lock, irqflags);
+
+       spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+       list_for_each(list, &dev_priv->vbl_swaps.head) {
+               vbl_swap = list_entry(list, drm_i915_vbl_swap_t, head);
+
+               if (vbl_swap->drw_id == swap.drawable &&
+                   vbl_swap->pipe == swap.pipe &&
+                   vbl_swap->sequence == swap.sequence) {
+                       spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+                       DRM_DEBUG("Already scheduled\n");
+                       return 0;
+               }
+       }
+
+       spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+
+       vbl_swap = drm_calloc(1, sizeof(vbl_swap), DRM_MEM_DRIVER);
+
+       if (!vbl_swap) {
+               DRM_ERROR("Failed to allocate memory to queue swap\n");
+               return DRM_ERR(ENOMEM);
+       }
+
+       DRM_DEBUG("\n");
+
+       vbl_swap->drw_id = swap.drawable;
+       vbl_swap->pipe = swap.pipe;
+       vbl_swap->sequence = swap.sequence;
+
+       spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+       list_add_tail((struct list_head *)vbl_swap, &dev_priv->vbl_swaps.head);
+       dev_priv->swaps_pending++;
+
+       spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+
+       return 0;
+}
+
 /* drm_dma.h hooks
 */
 void i915_driver_irq_preinstall(drm_device_t * dev)
 {
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 
+       dev_priv->swaps_lock = SPIN_LOCK_UNLOCKED;
+       INIT_LIST_HEAD(&dev_priv->vbl_swaps.head);
+       dev_priv->swaps_pending = 0;
+
        i915_enable_interrupt(dev);
        DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
 }