drm/amdgpu: clean up discovery and preempt sysfs entries on shutdown

Fix a sysfs duplication error when reinitializing the device:

  sysfs: cannot create duplicate filename '.../ip_discovery'
  kobject_add_internal failed for ip_discovery with -EEXIST
  ...
  Failed to create device file mem_info_preempt_used (-17)

The failure is caused by stale sysfs entries not being removed during
device teardown, leading to -EEXIST when the driver is reprobed. In
particular:

- amdgpu_discovery sysfs kobjects were not fully torn down early enough,
  and ip_top remained non-NULL after cleanup
- the preempt manager sysfs attribute was removed only conditionally
  and not during the common hw fini path

Fix this by:
- making amdgpu_discovery_sysfs_fini() externally visible and clearing
  adev->discovery.ip_top to prevent reuse
- calling amdgpu_discovery_sysfs_fini() and
  amdgpu_preempt_mgr_sysfs_fini() from
  amdgpu_device_sys_interface_fini()

This ensures sysfs state is fully cleaned up before reprobe and avoids
duplicate kobject/file creation.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Geoffrey McRae <geoffrey.mcrae@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_device.c

@@ -3677,6 +3677,10 @@ static void amdgpu_device_sys_interface_fini(struct amdgpu_device *adev)
 		amdgpu_pm_sysfs_fini(adev);
 	if (adev->ucode_sysfs_en)
 		amdgpu_ucode_sysfs_fini(adev);
+
+	amdgpu_discovery_sysfs_fini(adev);
+	amdgpu_preempt_mgr_sysfs_fini(adev);
+
 	amdgpu_device_attr_sysfs_fini(adev);
 	amdgpu_fru_sysfs_fini(adev);
 
@@ -4210,6 +4214,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 
 	if (adev->mman.initialized)
 		drain_workqueue(adev->mman.bdev.wq);
+
 	adev->shutdown = true;
 
 	unregister_pm_notifier(&adev->pm_nb);

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

@@ -759,8 +759,6 @@ static int amdgpu_discovery_init(struct amdgpu_device *adev)
 	return r;
 }
 
-static void amdgpu_discovery_sysfs_fini(struct amdgpu_device *adev);
-
 void amdgpu_discovery_fini(struct amdgpu_device *adev)
 {
 	if (adev->discovery.ip_top && !adev->discovery.ip_top->standalone_mode)
@@ -1482,7 +1480,7 @@ static void amdgpu_discovery_sysfs_die_free(struct ip_die_entry *ip_die_entry)
 	kobject_put(&ip_die_entry->ip_kset.kobj);
 }
 
-static void amdgpu_discovery_sysfs_fini(struct amdgpu_device *adev)
+void amdgpu_discovery_sysfs_fini(struct amdgpu_device *adev)
 {
 	struct ip_discovery_top *ip_top = adev->discovery.ip_top;
 	struct list_head *el, *tmp;
@@ -1491,6 +1489,7 @@ static void amdgpu_discovery_sysfs_fini(struct amdgpu_device *adev)
 	if (!ip_top)
 		return;
 
+	adev->discovery.ip_top = NULL;
 	die_kset = &ip_top->die_kset;
 	spin_lock(&die_kset->list_lock);
 	list_for_each_prev_safe(el, tmp, &die_kset->list) {

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

@@ -41,6 +41,7 @@ struct amdgpu_discovery_info {
 	bool reserve_tmr;
 };
 
+void amdgpu_discovery_sysfs_fini(struct amdgpu_device *adev);
 void amdgpu_discovery_fini(struct amdgpu_device *adev);
 int amdgpu_discovery_set_ip_blocks(struct amdgpu_device *adev);
 

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

@@ -46,6 +46,17 @@ static ssize_t mem_info_preempt_used_show(struct device *dev,
 
 static DEVICE_ATTR_RO(mem_info_preempt_used);
 
+/**
+ * amdgpu_preempt_mgr_sysfs_fini - remove PREEMPT manager sysfs attributes
+ *
+ * @adev: amdgpu_device pointer
+ */
+void amdgpu_preempt_mgr_sysfs_fini(struct amdgpu_device *adev)
+{
+	if (adev->dev->kobj.sd)
+		device_remove_file(adev->dev, &dev_attr_mem_info_preempt_used);
+}
+
 /**
  * amdgpu_preempt_mgr_new - allocate a new node
  *
@@ -137,9 +148,6 @@ void amdgpu_preempt_mgr_fini(struct amdgpu_device *adev)
 	if (ret)
 		return;
 
-	if (adev->dev->kobj.sd)
-		device_remove_file(adev->dev, &dev_attr_mem_info_preempt_used);
-
 	ttm_resource_manager_cleanup(man);
 	ttm_set_driver_manager(&adev->mman.bdev, AMDGPU_PL_PREEMPT, NULL);
 }

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

@@ -140,6 +140,7 @@ int amdgpu_gtt_mgr_init(struct amdgpu_device *adev, uint64_t gtt_size);
 void amdgpu_gtt_mgr_fini(struct amdgpu_device *adev);
 int amdgpu_preempt_mgr_init(struct amdgpu_device *adev);
 void amdgpu_preempt_mgr_fini(struct amdgpu_device *adev);
+void amdgpu_preempt_mgr_sysfs_fini(struct amdgpu_device *adev);
 int amdgpu_vram_mgr_init(struct amdgpu_device *adev);
 void amdgpu_vram_mgr_fini(struct amdgpu_device *adev);