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>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c
new file mode 100644
index 0000000..5668ad9
--- /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;
+	}
+}