drm/amdgpu: change vm->task_info handling

This patch changes the handling and lifecycle of vm->task_info object.
The major changes are:
- vm->task_info is a dynamically allocated ptr now, and its uasge is
  reference counted.
- introducing two new helper funcs for task_info lifecycle management
    - amdgpu_vm_get_task_info: reference counts up task_info before
      returning this info
    - amdgpu_vm_put_task_info: reference counts down task_info
- last put to task_info() frees task_info from the vm.

This patch also does logistical changes required for existing usage
of vm->task_info.

V2: Do not block all the prints when task_info not found (Felix)

V3: Fixed review comments from Felix
   - Fix wrong indentation
   - No debug message for -ENOMEM
   - Add NULL check for task_info
   - Do not duplicate the debug messages (ti vs no ti)
   - Get first reference of task_info in vm_init(), put last
     in vm_fini()

V4: Fixed review comments from Felix
   - fix double reference increment in create_task_info
   - change amdgpu_vm_get_task_info_pasid
   - additional changes in amdgpu_gem.c while porting

Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 969a9e867170..d20e5f20ee31 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -1445,18 +1445,24 @@ static int gmc_v8_0_process_interrupt(struct amdgpu_device *adev,
 		gmc_v8_0_set_fault_enable_default(adev, false);
 
 	if (printk_ratelimit()) {
-		struct amdgpu_task_info task_info;
+		struct amdgpu_task_info *task_info;
 
-		memset(&task_info, 0, sizeof(struct amdgpu_task_info));
-		amdgpu_vm_get_task_info(adev, entry->pasid, &task_info);
+		dev_err(adev->dev, "GPU fault detected: %d 0x%08x\n",
+			entry->src_id, entry->src_data[0]);
+
+		task_info = amdgpu_vm_get_task_info_pasid(adev, entry->pasid);
+		if (task_info) {
+			dev_err(adev->dev, " for process %s pid %d thread %s pid %d\n",
+				task_info->process_name, task_info->tgid,
+				task_info->task_name, task_info->pid);
+			amdgpu_vm_put_task_info(task_info);
+		}
 
-		dev_err(adev->dev, "GPU fault detected: %d 0x%08x for process %s pid %d thread %s pid %d\n",
-			entry->src_id, entry->src_data[0], task_info.process_name,
-			task_info.tgid, task_info.task_name, task_info.pid);
 		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_ADDR   0x%08X\n",
-			addr);
+				addr);
 		dev_err(adev->dev, "  VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x%08X\n",
 			status);
+
 		gmc_v8_0_vm_decode_fault(adev, status, addr, mc_client,
 					 entry->pasid);
 	}