[PATCH 03/10] drm/amdgpu:fix NULL pointer access during drv remove

[Monk Liu]

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()

Change-Id: Ib1f31a2cf6bfbb9b54c7cc2a8cf9e4e3160bcfa0
Signed-off-by: Monk Liu <Monk.Liu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c | 15 +++++----------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c  |  1 -
 drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c    |  2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c    |  2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c    |  2 +-
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c    |  2 +-
 6 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
index 4b5ec15..c4eef4a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c
@@ -255,10 +255,8 @@ 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;
@@ -273,14 +271,11 @@ 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;
+	if (adev->gart.pages) {
+		vfree(adev->gart.pages);
+		adev->gart.pages = NULL;
+	}
 #endif
 	amdgpu_dummy_page_fini(adev);
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index e8401a9..615b849 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1653,7 +1653,6 @@ 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");
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
index aac493b..6112dfc 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
@@ -894,9 +894,9 @@ 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;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
index dede91a..b57dc06 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
@@ -1067,9 +1067,9 @@ static int gmc_v7_0_sw_fini(void *handle)
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
 	kfree(adev->mc.vm_fault_info);
+	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;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 847c046..5be4854 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -1168,9 +1168,9 @@ static int gmc_v8_0_sw_fini(void *handle)
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
 	kfree(adev->mc.vm_fault_info);
+	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;
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index d0acf26..bea0774 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -667,9 +667,9 @@ 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;
-- 
2.7.4