drm/vmwgfx: Fix fencing on SVGAv3

Port of the vmwgfx to SVGAv3 lacked support for fencing. SVGAv3 removed
FIFO's and replaced them with command buffers and extra registers.
The initial version of SVGAv3 lacked support for most advanced features
(e.g. 3D) which made fences unnecessary. That is no longer the case,
especially as 3D support is being turned on.

Switch from FIFO commands and capabilities to command buffers and extra
registers to enable fences on SVGAv3.

Fixes: 2cd80dbd3551 ("drm/vmwgfx: Add basic support for SVGA3")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-5-zack@kde.org

1 files changed, 21 insertions, 7 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
index 59d6a2dd4c2e..66cc35dc223e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
@@ -82,6 +82,22 @@ fman_from_fence(struct vmw_fence_obj *fence)
 	return container_of(fence->base.lock, struct vmw_fence_manager, lock);
 }
 
+static u32 vmw_fence_goal_read(struct vmw_private *vmw)
+{
+	if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
+		return vmw_read(vmw, SVGA_REG_FENCE_GOAL);
+	else
+		return vmw_fifo_mem_read(vmw, SVGA_FIFO_FENCE_GOAL);
+}
+
+static void vmw_fence_goal_write(struct vmw_private *vmw, u32 value)
+{
+	if ((vmw->capabilities2 & SVGA_CAP2_EXTRA_REGS) != 0)
+		vmw_write(vmw, SVGA_REG_FENCE_GOAL, value);
+	else
+		vmw_fifo_mem_write(vmw, SVGA_FIFO_FENCE_GOAL, value);
+}
+
 /*
  * Note on fencing subsystem usage of irqs:
  * Typically the vmw_fences_update function is called
@@ -392,7 +408,7 @@ static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
 	if (likely(!fman->seqno_valid))
 		return false;
 
-	goal_seqno = vmw_fifo_mem_read(fman->dev_priv, SVGA_FIFO_FENCE_GOAL);
+	goal_seqno = vmw_fence_goal_read(fman->dev_priv);
 	if (likely(passed_seqno - goal_seqno >= VMW_FENCE_WRAP))
 		return false;
 
@@ -400,9 +416,8 @@ static bool vmw_fence_goal_new_locked(struct vmw_fence_manager *fman,
 	list_for_each_entry(fence, &fman->fence_list, head) {
 		if (!list_empty(&fence->seq_passed_actions)) {
 			fman->seqno_valid = true;
-			vmw_fifo_mem_write(fman->dev_priv,
-					   SVGA_FIFO_FENCE_GOAL,
-					   fence->base.seqno);
+			vmw_fence_goal_write(fman->dev_priv,
+					     fence->base.seqno);
 			break;
 		}
 	}
@@ -434,13 +449,12 @@ static bool vmw_fence_goal_check_locked(struct vmw_fence_obj *fence)
 	if (dma_fence_is_signaled_locked(&fence->base))
 		return false;
 
-	goal_seqno = vmw_fifo_mem_read(fman->dev_priv, SVGA_FIFO_FENCE_GOAL);
+	goal_seqno = vmw_fence_goal_read(fman->dev_priv);
 	if (likely(fman->seqno_valid &&
 		   goal_seqno - fence->base.seqno < VMW_FENCE_WRAP))
 		return false;
 
-	vmw_fifo_mem_write(fman->dev_priv, SVGA_FIFO_FENCE_GOAL,
-			   fence->base.seqno);
+	vmw_fence_goal_write(fman->dev_priv, fence->base.seqno);
 	fman->seqno_valid = true;
 
 	return true;