drm/amdgpu: extend lock range for race condition when gpu reset

to cover below case:
1. A task gart bind/unbind but not add to adev->gtt_list yet
2. at this time gpu reset, gtt only recover those gtt in adev->gtt_list

Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Roger.He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -554,7 +554,7 @@ int amdgpu_gart_table_vram_pin(struct amdgpu_device *adev);
 void amdgpu_gart_table_vram_unpin(struct amdgpu_device *adev);
 int amdgpu_gart_init(struct amdgpu_device *adev);
 void amdgpu_gart_fini(struct amdgpu_device *adev);
-void amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
+int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 			int pages);
 int amdgpu_gart_bind(struct amdgpu_device *adev, uint64_t offset,
 		     int pages, struct page **pagelist,

drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c

@@ -224,8 +224,9 @@ void amdgpu_gart_table_vram_free(struct amdgpu_device *adev)
  *
  * Unbinds the requested pages from the gart page table and
  * replaces them with the dummy page (all asics).
+ * Returns 0 for success, -EINVAL for failure.
  */
-void amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
+int amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 			int pages)
 {
 	unsigned t;
@@ -237,7 +238,7 @@ void amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 
 	if (!adev->gart.ready) {
 		WARN(1, "trying to unbind memory from uninitialized GART !\n");
-		return;
+		return -EINVAL;
 	}
 
 	t = offset / AMDGPU_GPU_PAGE_SIZE;
@@ -258,6 +259,7 @@ void amdgpu_gart_unbind(struct amdgpu_device *adev, uint64_t offset,
 	}
 	mb();
 	amdgpu_gart_flush_gpu_tlb(adev, 0);
+	return 0;
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -745,6 +745,7 @@ int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct ttm_mem_reg *bo_mem)
 		return r;
 	}
 
+	spin_lock(&gtt->adev->gtt_list_lock);
 	flags = amdgpu_ttm_tt_pte_flags(gtt->adev, ttm, bo_mem);
 	gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
 	r = amdgpu_gart_bind(gtt->adev, gtt->offset, ttm->num_pages,
@@ -753,12 +754,13 @@ int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct ttm_mem_reg *bo_mem)
 	if (r) {
 		DRM_ERROR("failed to bind %lu pages at 0x%08llX\n",
 			  ttm->num_pages, gtt->offset);
-		return r;
+		goto error_gart_bind;
 	}
-	spin_lock(&gtt->adev->gtt_list_lock);
+
 	list_add_tail(&gtt->list, &gtt->adev->gtt_list);
+error_gart_bind:
 	spin_unlock(&gtt->adev->gtt_list_lock);
-	return 0;
+	return r;
 }
 
 int amdgpu_ttm_recover_gart(struct amdgpu_device *adev)
@@ -789,6 +791,7 @@ int amdgpu_ttm_recover_gart(struct amdgpu_device *adev)
 static int amdgpu_ttm_backend_unbind(struct ttm_tt *ttm)
 {
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
+	int r;
 
 	if (gtt->userptr)
 		amdgpu_ttm_tt_unpin_userptr(ttm);
@@ -797,14 +800,17 @@ static int amdgpu_ttm_backend_unbind(struct ttm_tt *ttm)
 		return 0;
 
 	/* unbind shouldn't be done for GDS/GWS/OA in ttm_bo_clean_mm */
-	if (gtt->adev->gart.ready)
-		amdgpu_gart_unbind(gtt->adev, gtt->offset, ttm->num_pages);
-
 	spin_lock(&gtt->adev->gtt_list_lock);
+	r = amdgpu_gart_unbind(gtt->adev, gtt->offset, ttm->num_pages);
+	if (r) {
+		DRM_ERROR("failed to unbind %lu pages at 0x%08llX\n",
+			  gtt->ttm.ttm.num_pages, gtt->offset);
+		goto error_unbind;
+	}
 	list_del_init(&gtt->list);
+error_unbind:
 	spin_unlock(&gtt->adev->gtt_list_lock);
-
-	return 0;
+	return r;
 }
 
 static void amdgpu_ttm_backend_destroy(struct ttm_tt *ttm)