Some illegal combination of input flags were not checked and we need to
take the PDEs into account when returning the fence as well.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 76 +++++++++++--------------
 1 file changed, 34 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 88a21400ae09..98276b55ad3c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -30,6 +30,7 @@
 #include <linux/pagemap.h>
 #include <linux/pci.h>
 #include <linux/dma-buf.h>
+#include <linux/dma-fence-unwrap.h>
 
 #include <drm/amdgpu_drm.h>
 #include <drm/drm_drv.h>
@@ -741,11 +742,10 @@ amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
 	struct dma_fence *fence;
 	int r = 0;
 
-	/* Always start from the VM's existing last update fence. */
-	fence = dma_fence_get(vm->last_update);
-
+	/* If the VM is not ready return only a stub. */
 	if (!amdgpu_vm_ready(vm))
-		return fence;
+		return dma_fence_get_stub();
+
 
 	/*
 	 * First clean up any freed mappings in the VM.
@@ -754,7 +754,7 @@ amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
 	 * schedules GPU work. If nothing needs clearing, @fence can remain as
 	 * the original vm->last_update.
 	 */
-	r = amdgpu_vm_clear_freed(adev, vm, &fence);
+	r = amdgpu_vm_clear_freed(adev, vm, &vm->last_update);
 	if (r)
 		goto error;
 
@@ -771,47 +771,34 @@ amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
 	if (r)
 		goto error;
 
-	/*
-	 * Decide which fence best represents the last update:
-	 *
-	 * MAP/REPLACE:
-	 *   - For always-valid mappings, use vm->last_update.
-	 *   - Otherwise, export bo_va->last_pt_update.
-	 *
-	 * UNMAP/CLEAR:
-	 *   Keep the fence returned by amdgpu_vm_clear_freed(). If no work was
-	 *   needed, it can remain as vm->last_pt_update.
-	 *
-	 * The VM and BO update fences are always initialized to a valid value.
-	 * vm->last_update and bo_va->last_pt_update always start as valid fences.
-	 * and are never expected to be NULL.
-	 */
-	switch (operation) {
-	case AMDGPU_VA_OP_MAP:
-	case AMDGPU_VA_OP_REPLACE:
+	if ((operation == AMDGPU_VA_OP_MAP ||
+	     operation == AMDGPU_VA_OP_REPLACE) &&
+	    !amdgpu_vm_is_bo_always_valid(vm, bo_va->base.bo)) {
+
 		/*
-		 * For MAP/REPLACE, return the page table update fence for the
-		 * mapping we just modified. bo_va is expected to be valid here.
+		 * For MAP/REPLACE of non per-VM BOs we need to sync to both the
+		 * bo_va->last_pt_update and vm->last_update or otherwise we
+		 * potentially miss the PDE updates.
 		 */
-		dma_fence_put(fence);
-
-		if (amdgpu_vm_is_bo_always_valid(vm, bo_va->base.bo))
-			fence = dma_fence_get(vm->last_update);
-		else
-			fence = dma_fence_get(bo_va->last_pt_update);
-		break;
-	case AMDGPU_VA_OP_UNMAP:
-	case AMDGPU_VA_OP_CLEAR:
-	default:
-		/* keep @fence as returned by amdgpu_vm_clear_freed() */
-		break;
+		fence = dma_fence_unwrap_merge(vm->last_update,
+					       bo_va->last_pt_update);
+		if (!fence) {
+			/* As fallback in OOM situations */
+			dma_fence_wait(vm->last_update, false);
+			dma_fence_wait(bo_va->last_pt_update, false);
+			fence = dma_fence_get_stub();
+		}
+	} else {
+		fence = dma_fence_get(vm->last_update);
 	}
 
+	return fence;
+
 error:
 	if (r && r != -ERESTARTSYS)
 		DRM_ERROR("Couldn't update BO_VA (%d)\n", r);
 
-	return fence;
+	return dma_fence_get(vm->last_update);
 }
 
 int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
@@ -832,7 +819,6 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 	struct amdgpu_bo_va *bo_va;
 	struct drm_syncobj *timeline_syncobj = NULL;
 	struct dma_fence_chain *timeline_chain = NULL;
-	struct dma_fence *fence;
 	struct drm_exec exec;
 	uint64_t vm_size;
 	int r = 0;
@@ -884,6 +870,10 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	if (args->flags & AMDGPU_VM_DELAY_UPDATE &&
+	    args->vm_timeline_syncobj_out)
+		return -EINVAL;
+
 	if ((args->operation != AMDGPU_VA_OP_CLEAR) &&
 	    !(args->flags & AMDGPU_VM_PAGE_PRT)) {
 		gobj = drm_gem_object_lookup(filp, args->handle);
@@ -973,11 +963,13 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
 	 * that represents the last relevant update for this mapping. This
 	 * fence can then be exported to the user-visible VM timeline.
 	 */
-	if (!r && !(args->flags & AMDGPU_VM_DELAY_UPDATE) && !adev->debug_vm) {
+	if (!r && !(args->flags & AMDGPU_VM_DELAY_UPDATE) &&
+	    (!adev->debug_vm || timeline_syncobj)) {
+		struct dma_fence *fence;

Other than that small nitpick looks good to me. 

Acked-by: Sunil Khatri <sunil.khatri@amd.com>

Regards
Sunil khatri

+
 		fence = amdgpu_gem_va_update_vm(adev, &fpriv->vm, bo_va,
 						args->operation);
-
-		if (timeline_syncobj && fence) {
+		if (timeline_syncobj) {
 			if (!args->vm_timeline_point) {
 				/* Replace the existing fence when no point is given. */
 				drm_syncobj_replace_fence(timeline_syncobj,