drm/amdgpu: Fix error handling in slot reset

If the device has not recovered after slot reset is called, it goes to
out label for error handling. There it could make decision based on
uninitialized hive pointer and could result in accessing an uninitialized
list.

Initialize the list and hive properly so that it handles the error
situation and also releases the reset domain lock which is acquired
during error_detected callback.

Fixes: 732c6ce ("drm/amdgpu: Replace tmp_adev with hive in amdgpu_pci_slot_reset")
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Ce Sun <cesun102@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit bb71362)

Author: Lijo Lazar

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

@@ -7059,6 +7059,15 @@ pci_ers_result_t amdgpu_pci_slot_reset(struct pci_dev *pdev)
 	dev_info(adev->dev, "PCI error: slot reset callback!!\n");
 
 	memset(&reset_context, 0, sizeof(reset_context));
+	INIT_LIST_HEAD(&device_list);
+	hive = amdgpu_get_xgmi_hive(adev);
+	if (hive) {
+		mutex_lock(&hive->hive_lock);
+		list_for_each_entry(tmp_adev, &hive->device_list, gmc.xgmi.head)
+			list_add_tail(&tmp_adev->reset_list, &device_list);
+	} else {
+		list_add_tail(&adev->reset_list, &device_list);
+	}
 
 	if (adev->pcie_reset_ctx.swus)
 		link_dev = adev->pcie_reset_ctx.swus;
@@ -7099,19 +7108,13 @@ pci_ers_result_t amdgpu_pci_slot_reset(struct pci_dev *pdev)
 	reset_context.reset_req_dev = adev;
 	set_bit(AMDGPU_NEED_FULL_RESET, &reset_context.flags);
 	set_bit(AMDGPU_SKIP_COREDUMP, &reset_context.flags);
-	INIT_LIST_HEAD(&device_list);
 
-	hive = amdgpu_get_xgmi_hive(adev);
 	if (hive) {
-		mutex_lock(&hive->hive_lock);
 		reset_context.hive = hive;
-		list_for_each_entry(tmp_adev, &hive->device_list, gmc.xgmi.head) {
+		list_for_each_entry(tmp_adev, &hive->device_list, gmc.xgmi.head)
 			tmp_adev->pcie_reset_ctx.in_link_reset = true;
-			list_add_tail(&tmp_adev->reset_list, &device_list);
-		}
 	} else {
 		set_bit(AMDGPU_SKIP_HW_RESET, &reset_context.flags);
-		list_add_tail(&adev->reset_list, &device_list);
 	}
 
 	r = amdgpu_device_asic_reset(adev, &device_list, &reset_context);