vmwgfx: Add dmabuf helper functions for pinning

Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

7 files changed, 379 insertions, 107 deletions

diff --git a/drivers/gpu/drm/vmwgfx/Makefile b/drivers/gpu/drm/vmwgfx/Makefile
index 7d8e9d5d498..e13a118b2ee 100644
--- a/drivers/gpu/drm/vmwgfx/Makefile
+++ b/drivers/gpu/drm/vmwgfx/Makefile
@@ -5,6 +5,6 @@ vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_kms.o vmwgfx_drv.o \
             vmwgfx_fb.o vmwgfx_ioctl.o vmwgfx_resource.o vmwgfx_buffer.o \
             vmwgfx_fifo.o vmwgfx_irq.o vmwgfx_ldu.o vmwgfx_ttm_glue.o \
             vmwgfx_overlay.o vmwgfx_marker.o vmwgfx_gmrid_manager.o \
-            vmwgfx_fence.o
+            vmwgfx_fence.o vmwgfx_dmabuf.o
 
 obj-$(CONFIG_DRM_VMWGFX) := vmwgfx.o
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index 5d665ce8cbe..98a5d7e9054 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -42,6 +42,10 @@ static uint32_t sys_placement_flags = TTM_PL_FLAG_SYSTEM |
 static uint32_t gmr_placement_flags = VMW_PL_FLAG_GMR |
         TTM_PL_FLAG_CACHED;
 
+static uint32_t gmr_ne_placement_flags = VMW_PL_FLAG_GMR |
+        TTM_PL_FLAG_CACHED |
+        TTM_PL_FLAG_NO_EVICT;
+
 struct ttm_placement vmw_vram_placement = {
         .fpfn = 0,
         .lpfn = 0,
@@ -65,6 +69,20 @@ struct ttm_placement vmw_vram_gmr_placement = {
         .busy_placement = &gmr_placement_flags
 };
 
+static uint32_t vram_gmr_ne_placement_flags[] = {
+        TTM_PL_FLAG_VRAM | TTM_PL_FLAG_CACHED | TTM_PL_FLAG_NO_EVICT,
+        VMW_PL_FLAG_GMR | TTM_PL_FLAG_CACHED | TTM_PL_FLAG_NO_EVICT
+};
+
+struct ttm_placement vmw_vram_gmr_ne_placement = {
+        .fpfn = 0,
+        .lpfn = 0,
+        .num_placement = 2,
+        .placement = vram_gmr_ne_placement_flags,
+        .num_busy_placement = 1,
+        .busy_placement = &gmr_ne_placement_flags
+};
+
 struct ttm_placement vmw_vram_sys_placement = {
         .fpfn = 0,
         .lpfn = 0,
@@ -92,6 +110,21 @@ struct ttm_placement vmw_sys_placement = {
         .busy_placement = &sys_placement_flags
 };
 
+static uint32_t evictable_placement_flags[] = {
+        TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED,
+        TTM_PL_FLAG_VRAM | TTM_PL_FLAG_CACHED,
+        VMW_PL_FLAG_GMR | TTM_PL_FLAG_CACHED
+};
+
+struct ttm_placement vmw_evictable_placement = {
+        .fpfn = 0,
+        .lpfn = 0,
+        .num_placement = 3,
+        .placement = evictable_placement_flags,
+        .num_busy_placement = 1,
+        .busy_placement = &sys_placement_flags
+};
+
 struct vmw_ttm_backend {
         struct ttm_backend backend;
         struct page **pages;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
new file mode 100644
index 00000000000..5668ad980cb
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
@@ -0,0 +1,292 @@
+/**************************************************************************
+ *
+ * Copyright © 2011 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 "ttm/ttm_placement.h"
+
+#include "drmP.h"
+#include "vmwgfx_drv.h"
+
+
+/**
+ * Validate a buffer to placement.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * Returns
+ *  -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_to_placement(struct vmw_private *dev_priv,
+                            struct vmw_dma_buffer *buf,
+                            struct ttm_placement *placement,
+                            bool interruptible)
+{
+        struct vmw_master *vmaster = dev_priv->active_master;
+        struct ttm_buffer_object *bo = &buf->base;
+        int ret;
+
+        ret = ttm_write_lock(&vmaster->lock, interruptible);
+        if (unlikely(ret != 0))
+                return ret;
+
+        ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+        if (unlikely(ret != 0))
+                goto err;
+
+        ret = ttm_bo_validate(bo, placement, interruptible, false, false);
+
+        ttm_bo_unreserve(bo);
+
+err:
+        ttm_write_unlock(&vmaster->lock);
+        return ret;
+}
+
+/**
+ * Move a buffer to vram or gmr.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * @dev_priv:  Driver private.
+ * @buf:  DMA buffer to move.
+ * @pin:  Pin buffer if true.
+ * @interruptible:  Use interruptible wait.
+ *
+ * Returns
+ * -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_to_vram_or_gmr(struct vmw_private *dev_priv,
+                              struct vmw_dma_buffer *buf,
+                              bool pin, bool interruptible)
+{
+        struct vmw_master *vmaster = dev_priv->active_master;
+        struct ttm_buffer_object *bo = &buf->base;
+        struct ttm_placement *placement;
+        int ret;
+
+        ret = ttm_write_lock(&vmaster->lock, interruptible);
+        if (unlikely(ret != 0))
+                return ret;
+
+        ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+        if (unlikely(ret != 0))
+                goto err;
+
+        /**
+         * Put BO in VRAM if there is space, otherwise as a GMR.
+         * If there is no space in VRAM and GMR ids are all used up,
+         * start evicting GMRs to make room. If the DMA buffer can't be
+         * used as a GMR, this will return -ENOMEM.
+         */
+
+        if (pin)
+                placement = &vmw_vram_gmr_ne_placement;
+        else
+                placement = &vmw_vram_gmr_placement;
+
+        ret = ttm_bo_validate(bo, placement, interruptible, false, false);
+        if (likely(ret == 0) || ret == -ERESTARTSYS)
+                goto err_unreserve;
+
+
+        /**
+         * If that failed, try VRAM again, this time evicting
+         * previous contents.
+         */
+
+        if (pin)
+                placement = &vmw_vram_ne_placement;
+        else
+                placement = &vmw_vram_placement;
+
+        ret = ttm_bo_validate(bo, placement, interruptible, false, false);
+
+err_unreserve:
+        ttm_bo_unreserve(bo);
+err:
+        ttm_write_unlock(&vmaster->lock);
+        return ret;
+}
+
+/**
+ * Move a buffer to vram.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * @dev_priv:  Driver private.
+ * @buf:  DMA buffer to move.
+ * @pin:  Pin buffer in vram if true.
+ * @interruptible:  Use interruptible wait.
+ *
+ * Returns
+ * -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_to_vram(struct vmw_private *dev_priv,
+                       struct vmw_dma_buffer *buf,
+                       bool pin, bool interruptible)
+{
+        struct ttm_placement *placement;
+
+        if (pin)
+                placement = &vmw_vram_ne_placement;
+        else
+                placement = &vmw_vram_placement;
+
+        return vmw_dmabuf_to_placement(dev_priv, buf,
+                                       placement,
+                                       interruptible);
+}
+
+/**
+ * Move a buffer to start of vram.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * @dev_priv:  Driver private.
+ * @buf:  DMA buffer to move.
+ * @pin:  Pin buffer in vram if true.
+ * @interruptible:  Use interruptible wait.
+ *
+ * Returns
+ * -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_to_start_of_vram(struct vmw_private *dev_priv,
+                                struct vmw_dma_buffer *buf,
+                                bool pin, bool interruptible)
+{
+        struct vmw_master *vmaster = dev_priv->active_master;
+        struct ttm_buffer_object *bo = &buf->base;
+        struct ttm_placement placement;
+        int ret = 0;
+
+        if (pin)
+                placement = vmw_vram_ne_placement;
+        else
+                placement = vmw_vram_placement;
+        placement.lpfn = bo->num_pages;
+
+        ret = ttm_write_lock(&vmaster->lock, interruptible);
+        if (unlikely(ret != 0))
+                return ret;
+
+        ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
+        if (unlikely(ret != 0))
+                goto err_unlock;
+
+        /* Is this buffer already in vram but not at the start of it? */
+        if (bo->mem.mem_type == TTM_PL_VRAM &&
+            bo->mem.start < bo->num_pages &&
+            bo->mem.start > 0)
+                (void) ttm_bo_validate(bo, &vmw_sys_placement, false,
+                                       false, false);
+
+        ret = ttm_bo_validate(bo, &placement, interruptible, false, false);
+
+        /* For some reason we didn't up at the start of vram */
+        WARN_ON(ret == 0 && bo->offset != 0);
+
+        ttm_bo_unreserve(bo);
+err_unlock:
+        ttm_write_unlock(&vmaster->lock);
+
+        return ret;
+}
+
+/**
+ * Unpin the buffer given buffer, does not move the buffer.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * @dev_priv:  Driver private.
+ * @buf:  DMA buffer to unpin.
+ * @interruptible:  Use interruptible wait.
+ *
+ * Returns
+ * -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_unpin(struct vmw_private *dev_priv,
+                     struct vmw_dma_buffer *buf,
+                     bool interruptible)
+{
+        /*
+         * We could in theory early out if the buffer is
+         * unpinned but we need to lock and reserve the buffer
+         * anyways so we don't gain much by that.
+         */
+        return vmw_dmabuf_to_placement(dev_priv, buf,
+                                       &vmw_evictable_placement,
+                                       interruptible);
+}
+
+/**
+ * Move a buffer to system memory, does not pin the buffer.
+ *
+ * May only be called by the current master as this function takes the
+ * its lock in write mode.
+ *
+ * @dev_priv:  Driver private.
+ * @buf:  DMA buffer to move.
+ * @interruptible:  Use interruptible wait.
+ *
+ * Returns
+ * -ERESTARTSYS if interrupted by a signal.
+ */
+int vmw_dmabuf_to_system(struct vmw_private *dev_priv,
+                         struct vmw_dma_buffer *buf,
+                         bool interruptible)
+{
+        return vmw_dmabuf_to_placement(dev_priv, buf,
+                                       &vmw_sys_placement,
+                                       interruptible);
+}
+
+void vmw_dmabuf_get_id_offset(struct vmw_dma_buffer *buf,
+                              uint32_t *gmrId, uint32_t *offset)
+{
+        if (buf->base.mem.mem_type == TTM_PL_VRAM) {
+                *gmrId = SVGA_GMR_FRAMEBUFFER;
+                *offset = buf->base.offset;
+        } else {
+                *gmrId = buf->base.mem.start;
+                *offset = 0;
+        }
+}
+
+void vmw_dmabuf_get_guest_ptr(struct vmw_dma_buffer *buf, SVGAGuestPtr *ptr)
+{
+        if (buf->base.mem.mem_type == TTM_PL_VRAM) {
+                ptr->gmrId = SVGA_GMR_FRAMEBUFFER;
+                ptr->offset = buf->base.offset;
+        } else {
+                ptr->gmrId = buf->base.mem.start;
+                ptr->offset = 0;
+        }
+}
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index edd1e8362f3..5acf1f2c498 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -385,10 +385,6 @@ extern uint32_t vmw_dmabuf_validate_node(struct ttm_buffer_object *bo,
 extern void vmw_dmabuf_validate_clear(struct ttm_buffer_object *bo);
 extern int vmw_user_dmabuf_lookup(struct ttm_object_file *tfile,
                                   uint32_t id, struct vmw_dma_buffer **out);
-extern int vmw_dmabuf_to_start_of_vram(struct vmw_private *vmw_priv,
-                                       struct vmw_dma_buffer *bo);
-extern int vmw_dmabuf_from_vram(struct vmw_private *vmw_priv,
-                                struct vmw_dma_buffer *bo);
 extern int vmw_stream_claim_ioctl(struct drm_device *dev, void *data,
                                   struct drm_file *file_priv);
 extern int vmw_stream_unref_ioctl(struct drm_device *dev, void *data,
@@ -398,6 +394,32 @@ extern int vmw_user_stream_lookup(struct vmw_private *dev_priv,
                                   uint32_t *inout_id,
                                   struct vmw_resource **out);
 
+/**
+ * DMA buffer helper routines - vmwgfx_dmabuf.c
+ */
+extern int vmw_dmabuf_to_placement(struct vmw_private *vmw_priv,
+                                   struct vmw_dma_buffer *bo,
+                                   struct ttm_placement *placement,
+                                   bool interruptible);
+extern int vmw_dmabuf_to_vram(struct vmw_private *dev_priv,
+                              struct vmw_dma_buffer *buf,
+                              bool pin, bool interruptible);
+extern int vmw_dmabuf_to_vram_or_gmr(struct vmw_private *dev_priv,
+                                     struct vmw_dma_buffer *buf,
+                                     bool pin, bool interruptible);
+extern int vmw_dmabuf_to_start_of_vram(struct vmw_private *vmw_priv,
+                                       struct vmw_dma_buffer *bo,
+                                       bool pin, bool interruptible);
+extern int vmw_dmabuf_unpin(struct vmw_private *vmw_priv,
+                            struct vmw_dma_buffer *bo,
+                            bool interruptible);
+extern int vmw_dmabuf_to_system(struct vmw_private *vmw_priv,
+                                struct vmw_dma_buffer *bo,
+                                bool interruptible);
+extern void vmw_dmabuf_get_id_offset(struct vmw_dma_buffer *buf,
+                                     uint32_t *gmrId, uint32_t *offset);
+extern void vmw_dmabuf_get_guest_ptr(struct vmw_dma_buffer *buf,
+                                     SVGAGuestPtr *ptr);
 
 /**
  * Misc Ioctl functionality - vmwgfx_ioctl.c
@@ -440,7 +462,9 @@ extern struct ttm_placement vmw_vram_placement;
 extern struct ttm_placement vmw_vram_ne_placement;
 extern struct ttm_placement vmw_vram_sys_placement;
 extern struct ttm_placement vmw_vram_gmr_placement;
+extern struct ttm_placement vmw_vram_gmr_ne_placement;
 extern struct ttm_placement vmw_sys_placement;
+extern struct ttm_placement vmw_evictable_placement;
 extern struct ttm_bo_driver vmw_bo_driver;
 extern int vmw_dma_quiescent(struct drm_device *dev);
 
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index b1888e801e2..191f1b2a2a2 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -592,58 +592,6 @@ int vmw_fb_close(struct vmw_private *vmw_priv)
         return 0;
 }
 
-int vmw_dmabuf_from_vram(struct vmw_private *vmw_priv,
-                         struct vmw_dma_buffer *vmw_bo)
-{
-        struct ttm_buffer_object *bo = &vmw_bo->base;
-        int ret = 0;
-
-        ret = ttm_bo_reserve(bo, false, false, false, 0);
-        if (unlikely(ret != 0))
-                return ret;
-
-        ret = ttm_bo_validate(bo, &vmw_sys_placement, false, false, false);
-        ttm_bo_unreserve(bo);
-
-        return ret;
-}
-
-int vmw_dmabuf_to_start_of_vram(struct vmw_private *vmw_priv,
-                                struct vmw_dma_buffer *vmw_bo)
-{
-        struct ttm_buffer_object *bo = &vmw_bo->base;
-        struct ttm_placement ne_placement = vmw_vram_ne_placement;
-        int ret = 0;
-
-        ne_placement.lpfn = bo->num_pages;
-
-        /* interuptable? */
-        ret = ttm_write_lock(&vmw_priv->active_master->lock, false);
-        if (unlikely(ret != 0))
-                return ret;
-
-        ret = ttm_bo_reserve(bo, false, false, false, 0);
-        if (unlikely(ret != 0))
-                goto err_unlock;
-
-        if (bo->mem.mem_type == TTM_PL_VRAM &&
-            bo->mem.start < bo->num_pages &&
-            bo->mem.start > 0)
-                (void) ttm_bo_validate(bo, &vmw_sys_placement, false,
-                                       false, false);
-
-        ret = ttm_bo_validate(bo, &ne_placement, false, false, false);
-
-        /* Could probably bug on */
-        WARN_ON(bo->offset != 0);
-
-        ttm_bo_unreserve(bo);
-err_unlock:
-        ttm_write_unlock(&vmw_priv->active_master->lock);
-
-        return ret;
-}
-
 int vmw_fb_off(struct vmw_private *vmw_priv)
 {
         struct fb_info *info;
@@ -665,7 +613,8 @@ int vmw_fb_off(struct vmw_private *vmw_priv)
         par->bo_ptr = NULL;
         ttm_bo_kunmap(&par->map);
 
-        vmw_dmabuf_from_vram(vmw_priv, par->vmw_bo);
+        /* move this to system instead of just unpinning it */
+        vmw_dmabuf_to_system(vmw_priv, par->vmw_bo, false);
 
         return 0;
 }
@@ -691,7 +640,7 @@ int vmw_fb_on(struct vmw_private *vmw_priv)
         /* 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);
+        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;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index c34866ab352..b3d5120b1f4 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -804,7 +804,7 @@ static int vmw_framebuffer_dmabuf_pin(struct vmw_framebuffer *vfb)
 
         vmw_overlay_pause_all(dev_priv);
 
-        ret = vmw_dmabuf_to_start_of_vram(dev_priv, vfbd->buffer);
+        ret = vmw_dmabuf_to_start_of_vram(dev_priv, vfbd->buffer, true, false);
 
         vmw_overlay_resume_all(dev_priv);
 
@@ -824,7 +824,7 @@ static int vmw_framebuffer_dmabuf_unpin(struct vmw_framebuffer *vfb)
                 return 0;
         }
 
-        return vmw_dmabuf_from_vram(dev_priv, vfbd->buffer);
+        return vmw_dmabuf_unpin(dev_priv, vfbd->buffer, false);
 }
 
 static int vmw_kms_new_framebuffer_dmabuf(struct vmw_private *dev_priv,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_overlay.c b/drivers/gpu/drm/vmwgfx/vmwgfx_overlay.c
index 07ce02da78a..7a7abcdf102 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_overlay.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_overlay.c
@@ -87,48 +87,6 @@ static inline void fill_flush(struct vmw_escape_video_flush *cmd,
 }
 
 /**
- * Pin or unpin a buffer in vram.
- *
- * @dev_priv:  Driver private.
- * @buf:  DMA buffer to pin or unpin.
- * @pin:  Pin buffer in vram if true.
- * @interruptible:  Use interruptible wait.
- *
- * Takes the current masters ttm lock in read.
- *
- * Returns
- * -ERESTARTSYS if interrupted by a signal.
- */
-static int vmw_dmabuf_pin_in_vram(struct vmw_private *dev_priv,
-                                  struct vmw_dma_buffer *buf,
-                                  bool pin, bool interruptible)
-{
-        struct ttm_buffer_object *bo = &buf->base;
-        struct ttm_placement *overlay_placement = &vmw_vram_placement;
-        int ret;
-
-        ret = ttm_read_lock(&dev_priv->active_master->lock, interruptible);
-        if (unlikely(ret != 0))
-                return ret;
-
-        ret = ttm_bo_reserve(bo, interruptible, false, false, 0);
-        if (unlikely(ret != 0))
-                goto err;
-
-        if (pin)
-                overlay_placement = &vmw_vram_ne_placement;
-
-        ret = ttm_bo_validate(bo, overlay_placement, interruptible, false, false);
-
-        ttm_bo_unreserve(bo);
-
-err:
-        ttm_read_unlock(&dev_priv->active_master->lock);
-
-        return ret;
-}
-
-/**
  * Send put command to hw.
  *
  * Returns
@@ -248,6 +206,21 @@ static int vmw_overlay_send_stop(struct vmw_private *dev_priv,
 }
 
 /**
+ * Move a buffer to vram, and pin it if @pin.
+ *
+ * XXX: This function is here to be changed at a later date.
+ */
+static int vmw_overlay_move_buffer(struct vmw_private *dev_priv,
+                                   struct vmw_dma_buffer *buf,
+                                   bool pin, bool inter)
+{
+        if (pin)
+                return vmw_dmabuf_to_vram(dev_priv, buf, true, inter);
+        else
+                return vmw_dmabuf_unpin(dev_priv, buf, inter);
+}
+
+/**
  * Stop or pause a stream.
  *
  * If the stream is paused the no evict flag is removed from the buffer
@@ -279,8 +252,8 @@ static int vmw_overlay_stop(struct vmw_private *dev_priv,
                         return ret;
 
                 /* We just remove the NO_EVICT flag so no -ENOMEM */
-                ret = vmw_dmabuf_pin_in_vram(dev_priv, stream->buf, false,
-                                             interruptible);
+                ret = vmw_overlay_move_buffer(dev_priv, stream->buf, false,
+                                              interruptible);
                 if (interruptible && ret == -ERESTARTSYS)
                         return ret;
                 else
@@ -342,7 +315,7 @@ static int vmw_overlay_update_stream(struct vmw_private *dev_priv,
         /* We don't start the old stream if we are interrupted.
          * Might return -ENOMEM if it can't fit the buffer in vram.
          */
-        ret = vmw_dmabuf_pin_in_vram(dev_priv, buf, true, interruptible);
+        ret = vmw_overlay_move_buffer(dev_priv, buf, true, interruptible);
         if (ret)
                 return ret;
 
@@ -351,7 +324,8 @@ static int vmw_overlay_update_stream(struct vmw_private *dev_priv,
                 /* This one needs to happen no matter what. We only remove
                  * the NO_EVICT flag so this is safe from -ENOMEM.
                  */
-                BUG_ON(vmw_dmabuf_pin_in_vram(dev_priv, buf, false, false) != 0);
+                BUG_ON(vmw_overlay_move_buffer(dev_priv, buf, false, false)
+                       != 0);
                 return ret;
         }