vmwgfx: Fix recursive locking in hibernation with fbdev enabled

The vmwgfx_svga[enable|disable] functions were called during
hibernation preparation- and recovery, and they were trying to acquire the
reservation_sem that was already taken in suspend mode by the
pm notifier.

Fix this by providing similar functions that don't try to acquire the
reservation sem, and that are intended to be used from the pm code.

Also fix a minor issue resulting from trying to remove the MOB memory type
during driver takedown, even on HW10.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

1 files changed, 53 insertions, 9 deletions

diff --git a/vmwgfx_drv.c b/vmwgfx_drv.c
index 168173c..5ad195a 100644
--- a/vmwgfx_drv.c
+++ b/vmwgfx_drv.c
@@ -898,7 +898,8 @@ static int vmw_driver_unload(struct drm_device *dev)
 	(void)ttm_bo_clean_mm(&dev_priv->bdev, TTM_PL_VRAM);
 
 	vmw_release_device_early(dev_priv);
-	(void)ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
+	if (dev_priv->has_mob)
+		(void)ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
 	(void)ttm_bo_device_release(&dev_priv->bdev);
 	vmw_release_device_late(dev_priv);
 	vmw_fence_manager_takedown(dev_priv->fman);
@@ -1242,29 +1243,72 @@ static void vmw_master_drop(struct drm_device *dev,
 		vmw_fb_on(dev_priv);
 }
 
-void vmw_svga_enable(struct vmw_private *dev_priv)
+/**
+ * __vmw_svga_enable - Enable SVGA mode, FIFO and use of VRAM.
+ *
+ * @dev_priv: Pointer to device private struct.
+ * Needs the reservation sem to be held in non-exclusive mode.
+ */
+void __vmw_svga_enable(struct vmw_private *dev_priv)
 {
-	ttm_read_lock(&dev_priv->reservation_sem, false);
 	spin_lock(&dev_priv->svga_lock);
 	if (!dev_priv->bdev.man[TTM_PL_VRAM].use_type) {
 		vmw_write(dev_priv, SVGA_REG_ENABLE, SVGA_REG_ENABLE);
 		dev_priv->bdev.man[TTM_PL_VRAM].use_type = true;
 	}
 	spin_unlock(&dev_priv->svga_lock);
+}
+
+/**
+ * vmw_svga_enable - Enable SVGA mode, FIFO and use of VRAM.
+ *
+ * @dev_priv: Pointer to device private struct.
+ */
+void vmw_svga_enable(struct vmw_private *dev_priv)
+{
+	ttm_read_lock(&dev_priv->reservation_sem, false);
+	__vmw_svga_enable(dev_priv);
 	ttm_read_unlock(&dev_priv->reservation_sem);
 }
 
+/**
+ * __vmw_svga_disable - Disable SVGA mode and use of VRAM.
+ *
+ * @dev_priv: Pointer to device private struct.
+ * Needs the reservation sem to be held in exclusive mode.
+ * Will not empty VRAM. VRAM must be emptied by caller.
+ */
+void __vmw_svga_disable(struct vmw_private *dev_priv)
+{
+	spin_lock(&dev_priv->svga_lock);
+	if (dev_priv->bdev.man[TTM_PL_VRAM].use_type) {
+		dev_priv->bdev.man[TTM_PL_VRAM].use_type = false;
+		vmw_write(dev_priv, SVGA_REG_ENABLE,
+			  SVGA_REG_ENABLE_ENABLE_HIDE);
+	}
+	spin_unlock(&dev_priv->svga_lock);
+}
+
+/**
+ * vmw_svga_disable - Disable SVGA_MODE, and use of VRAM. Keep the fifo
+ * running.
+ *
+ * @dev_priv: Pointer to device private struct.
+ * Will empty VRAM.
+ */
 void vmw_svga_disable(struct vmw_private *dev_priv)
 {
 	ttm_write_lock(&dev_priv->reservation_sem, false);
+	spin_lock(&dev_priv->svga_lock);
 	if (dev_priv->bdev.man[TTM_PL_VRAM].use_type) {
 		dev_priv->bdev.man[TTM_PL_VRAM].use_type = false;
-		if (ttm_bo_evict_mm(&dev_priv->bdev, TTM_PL_VRAM))
-			DRM_ERROR("Failed evicting VRAM buffers.\n");
-
 		vmw_write(dev_priv, SVGA_REG_ENABLE,
 			  SVGA_REG_ENABLE_ENABLE_HIDE);
-	}
+		spin_unlock(&dev_priv->svga_lock);
+		if (ttm_bo_evict_mm(&dev_priv->bdev, TTM_PL_VRAM))
+			DRM_ERROR("Failed evicting VRAM buffers.\n");
+	} else
+		spin_unlock(&dev_priv->svga_lock);
 	ttm_write_unlock(&dev_priv->reservation_sem);
 }
 
@@ -1362,7 +1406,7 @@ static int vmw_pm_freeze(struct device *kdev)
 	}
 
 	if (dev_priv->enable_fb)
-		vmw_svga_disable(dev_priv);
+		__vmw_svga_disable(dev_priv);
 
 	vmw_release_device_late(dev_priv);
 
@@ -1387,7 +1431,7 @@ static int vmw_pm_restore(struct device *kdev)
 		return ret;
 
 	if (dev_priv->enable_fb)
-		vmw_svga_enable(dev_priv);
+		__vmw_svga_enable(dev_priv);
 
 	dev_priv->suspended = false;