drm/amdgpu:fix NULL pointer access during drv remove

NULL pointer is because original logic will step into
set_pde_pte() even after the gart.ptr is freed due to
there are twice gart_unbind() on all gart area.

also, there are other minor fixes:
1,since gart_init only create dummy page, the corresponding
gart_fini shouldn't do more like unbinding all GART, this is
unnecessary because in driver fini stage all GART unbinding
had already been done during each IP's SW_FINI (GMC's
SW_FINI is the last one called), so remove the step
for the GART unbinding in gart_fini().

2,gart_fini() is already invoked during each GMC IP's gart_fini
routine,e.g. gmc_vx_0_gart_fini(), so no need to manually
call it during ttm_fini().

3,amdgpu_gem_force_release() should be put ahead of
amdgpu_vm_manager_fini()

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1412,6 +1412,7 @@ struct amdgpu_fw_vram_usage {
 };
 
 int amdgpu_fw_reserve_vram_init(struct amdgpu_device *adev);
+void amdgpu_fw_reserve_vram_fini(struct amdgpu_device *adev);
 
 /*
  * CGS

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

@@ -2506,7 +2506,6 @@ void amdgpu_device_fini(struct amdgpu_device *adev)
 	/* evict vram memory */
 	amdgpu_bo_evict_vram(adev);
 	amdgpu_ib_pool_fini(adev);
-	amdgpu_fw_reserve_vram_fini(adev);
 	amdgpu_fence_driver_fini(adev);
 	amdgpu_fbdev_fini(adev);
 	r = amdgpu_fini(adev);

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

@@ -253,10 +253,8 @@ int amdgpu_gart_init(struct amdgpu_device *adev)
 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
 	/* Allocate pages table */
 	adev->gart.pages = vzalloc(sizeof(void *) * adev->gart.num_cpu_pages);
-	if (adev->gart.pages == NULL) {
-		amdgpu_gart_fini(adev);
+	if (adev->gart.pages == NULL)
 		return -ENOMEM;
-	}
 #endif
 
 	return 0;
@@ -271,11 +269,6 @@ int amdgpu_gart_init(struct amdgpu_device *adev)
  */
 void amdgpu_gart_fini(struct amdgpu_device *adev)
 {
-	if (adev->gart.ready) {
-		/* unbind pages */
-		amdgpu_gart_unbind(adev, 0, adev->gart.num_cpu_pages);
-	}
-	adev->gart.ready = false;
 #ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS
 	vfree(adev->gart.pages);
 	adev->gart.pages = NULL;

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

@@ -1402,6 +1402,7 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
 
 	amdgpu_ttm_debugfs_fini(adev);
 	amdgpu_bo_free_kernel(&adev->stolen_vga_memory, NULL, NULL);
+	amdgpu_fw_reserve_vram_fini(adev);
 
 	ttm_bo_clean_mm(&adev->mman.bdev, TTM_PL_VRAM);
 	ttm_bo_clean_mm(&adev->mman.bdev, TTM_PL_TT);
@@ -1412,7 +1413,6 @@ void amdgpu_ttm_fini(struct amdgpu_device *adev)
 	if (adev->gds.oa.total_size)
 		ttm_bo_clean_mm(&adev->mman.bdev, AMDGPU_PL_OA);
 	ttm_bo_device_release(&adev->mman.bdev);
-	amdgpu_gart_fini(adev);
 	amdgpu_ttm_global_fini(adev);
 	adev->mman.initialized = false;
 	DRM_INFO("amdgpu: ttm finalized\n");

drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c

@@ -899,9 +899,9 @@ static int gmc_v6_0_sw_fini(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+	amdgpu_gem_force_release(adev);
 	amdgpu_vm_manager_fini(adev);
 	gmc_v6_0_gart_fini(adev);
-	amdgpu_gem_force_release(adev);
 	amdgpu_bo_fini(adev);
 	release_firmware(adev->mc.fw);
 	adev->mc.fw = NULL;

drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c

@@ -1049,9 +1049,9 @@ static int gmc_v7_0_sw_fini(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+	amdgpu_gem_force_release(adev);
 	amdgpu_vm_manager_fini(adev);
 	gmc_v7_0_gart_fini(adev);
-	amdgpu_gem_force_release(adev);
 	amdgpu_bo_fini(adev);
 	release_firmware(adev->mc.fw);
 	adev->mc.fw = NULL;

drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c

@@ -1146,9 +1146,9 @@ static int gmc_v8_0_sw_fini(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+	amdgpu_gem_force_release(adev);
 	amdgpu_vm_manager_fini(adev);
 	gmc_v8_0_gart_fini(adev);
-	amdgpu_gem_force_release(adev);
 	amdgpu_bo_fini(adev);
 	release_firmware(adev->mc.fw);
 	adev->mc.fw = NULL;

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -885,9 +885,9 @@ static int gmc_v9_0_sw_fini(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
+	amdgpu_gem_force_release(adev);
 	amdgpu_vm_manager_fini(adev);
 	gmc_v9_0_gart_fini(adev);
-	amdgpu_gem_force_release(adev);
 	amdgpu_bo_fini(adev);
 
 	return 0;