[PATCH 1/2] drm/vmwgfx: Fix a couple of lock dependency violations

[PATCH 1/2] drm/vmwgfx: Fix a couple of lock dependency violations

[Thomas Hellstrom]

Experimental lockdep annotation added to the TTM lock has unveiled a
couple of lock dependency violations in the vmwgfx driver. In both
cases it turns out that the device_private::reservation_sem is not
needed so the offending code is moved out of that lock.

Cc: <stable@vger.kernel.org>
Acked-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c |  8 +++-----
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c     | 14 +++-----------
 2 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
index 33176d0..1e11489 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c
@@ -2780,13 +2780,11 @@ int vmw_execbuf_ioctl(struct drm_device *dev, void *data,
 				  NULL, arg->command_size, arg->throttle_us,
 				  (void __user *)(unsigned long)arg->fence_rep,
 				  NULL);
-
+	ttm_read_unlock(&dev_priv->reservation_sem);
 	if (unlikely(ret != 0))
-		goto out_unlock;
+		return ret;
 
 	vmw_kms_cursor_post_execbuf(dev_priv);
 
-out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
-	return ret;
+	return 0;
 }
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 8725b79..07cda8c 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2033,23 +2033,17 @@ int vmw_kms_update_layout_ioctl(struct drm_device *dev, void *data,
 	int i;
 	struct drm_mode_config *mode_config = &dev->mode_config;
 
-	ret = ttm_read_lock(&dev_priv->reservation_sem, true);
-	if (unlikely(ret != 0))
-		return ret;
-
 	if (!arg->num_outputs) {
 		struct drm_vmw_rect def_rect = {0, 0, 800, 600};
 		vmw_du_update_layout(dev_priv, 1, &def_rect);
-		goto out_unlock;
+		return 0;
 	}
 
 	rects_size = arg->num_outputs * sizeof(struct drm_vmw_rect);
 	rects = kcalloc(arg->num_outputs, sizeof(struct drm_vmw_rect),
 			GFP_KERNEL);
-	if (unlikely(!rects)) {
-		ret = -ENOMEM;
-		goto out_unlock;
-	}
+	if (unlikely(!rects))
+		return -ENOMEM;
 
 	user_rects = (void __user *)(unsigned long)arg->rects;
 	ret = copy_from_user(rects, user_rects, rects_size);
@@ -2074,7 +2068,5 @@ int vmw_kms_update_layout_ioctl(struct drm_device *dev, void *data,
 
 out_free:
 	kfree(rects);
-out_unlock:
-	ttm_read_unlock(&dev_priv->reservation_sem);
 	return ret;
 }
-- 
2.1.0

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[PATCH 2/2] drm/vmwgfx: Reorder device takedown somewhat

[Thomas Hellstrom]

To take down the MOB and GMR memory types, the driver may have to issue
fence objects and thus make sure that the fence manager is taken down
after those memory types.
Reorder device init accordingly.

Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 77 +++++++++++++++++++------------------
 1 file changed, 40 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 6c6b655..74a2e23 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -725,32 +725,6 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 		goto out_err1;
 	}
 
-	ret = ttm_bo_init_mm(&dev_priv->bdev, TTM_PL_VRAM,
-			     (dev_priv->vram_size >> PAGE_SHIFT));
-	if (unlikely(ret != 0)) {
-		DRM_ERROR("Failed initializing memory manager for VRAM.\n");
-		goto out_err2;
-	}
-
-	dev_priv->has_gmr = true;
-	if (((dev_priv->capabilities & (SVGA_CAP_GMR | SVGA_CAP_GMR2)) == 0) ||
-	    refuse_dma || ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_GMR,
-					 VMW_PL_GMR) != 0) {
-		DRM_INFO("No GMR memory available. "
-			 "Graphics memory resources are very limited.\n");
-		dev_priv->has_gmr = false;
-	}
-
-	if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
-		dev_priv->has_mob = true;
-		if (ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_MOB,
-				   VMW_PL_MOB) != 0) {
-			DRM_INFO("No MOB memory available. "
-				 "3D will be disabled.\n");
-			dev_priv->has_mob = false;
-		}
-	}
-
 	dev_priv->mmio_mtrr = arch_phys_wc_add(dev_priv->mmio_start,
 					       dev_priv->mmio_size);
 
@@ -813,6 +787,33 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 		goto out_no_fman;
 	}
 
+
+	ret = ttm_bo_init_mm(&dev_priv->bdev, TTM_PL_VRAM,
+			     (dev_priv->vram_size >> PAGE_SHIFT));
+	if (unlikely(ret != 0)) {
+		DRM_ERROR("Failed initializing memory manager for VRAM.\n");
+		goto out_no_vram;
+	}
+
+	dev_priv->has_gmr = true;
+	if (((dev_priv->capabilities & (SVGA_CAP_GMR | SVGA_CAP_GMR2)) == 0) ||
+	    refuse_dma || ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_GMR,
+					 VMW_PL_GMR) != 0) {
+		DRM_INFO("No GMR memory available. "
+			 "Graphics memory resources are very limited.\n");
+		dev_priv->has_gmr = false;
+	}
+
+	if (dev_priv->capabilities & SVGA_CAP_GBOBJECTS) {
+		dev_priv->has_mob = true;
+		if (ttm_bo_init_mm(&dev_priv->bdev, VMW_PL_MOB,
+				   VMW_PL_MOB) != 0) {
+			DRM_INFO("No MOB memory available. "
+				 "3D will be disabled.\n");
+			dev_priv->has_mob = false;
+		}
+	}
+
 	vmw_kms_save_vga(dev_priv);
 
 	/* Start kms and overlay systems, needs fifo. */
@@ -838,6 +839,12 @@ out_no_fifo:
 	vmw_kms_close(dev_priv);
 out_no_kms:
 	vmw_kms_restore_vga(dev_priv);
+	if (dev_priv->has_mob)
+		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
+	if (dev_priv->has_gmr)
+		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_GMR);
+	(void)ttm_bo_clean_mm(&dev_priv->bdev, TTM_PL_VRAM);
+out_no_vram:
 	vmw_fence_manager_takedown(dev_priv->fman);
 out_no_fman:
 	if (dev_priv->capabilities & SVGA_CAP_IRQMASK)
@@ -853,12 +860,6 @@ out_err4:
 	iounmap(dev_priv->mmio_virt);
 out_err3:
 	arch_phys_wc_del(dev_priv->mmio_mtrr);
-	if (dev_priv->has_mob)
-		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
-	if (dev_priv->has_gmr)
-		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_GMR);
-	(void)ttm_bo_clean_mm(&dev_priv->bdev, TTM_PL_VRAM);
-out_err2:
 	(void)ttm_bo_device_release(&dev_priv->bdev);
 out_err1:
 	vmw_ttm_global_release(dev_priv);
@@ -887,6 +888,13 @@ static int vmw_driver_unload(struct drm_device *dev)
 	}
 	vmw_kms_close(dev_priv);
 	vmw_overlay_close(dev_priv);
+
+	if (dev_priv->has_mob)
+		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
+	if (dev_priv->has_gmr)
+		(void)ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_GMR);
+	(void)ttm_bo_clean_mm(&dev_priv->bdev, TTM_PL_VRAM);
+
 	vmw_fence_manager_takedown(dev_priv->fman);
 	if (dev_priv->capabilities & SVGA_CAP_IRQMASK)
 		drm_irq_uninstall(dev_priv->dev);
@@ -898,11 +906,6 @@ static int vmw_driver_unload(struct drm_device *dev)
 	ttm_object_device_release(&dev_priv->tdev);
 	iounmap(dev_priv->mmio_virt);
 	arch_phys_wc_del(dev_priv->mmio_mtrr);
-	if (dev_priv->has_mob)
-		(void) ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_MOB);
-	if (dev_priv->has_gmr)
-		(void)ttm_bo_clean_mm(&dev_priv->bdev, VMW_PL_GMR);
-	(void)ttm_bo_clean_mm(&dev_priv->bdev, TTM_PL_VRAM);
 	(void)ttm_bo_device_release(&dev_priv->bdev);
 	vmw_ttm_global_release(dev_priv);
 
-- 
2.1.0