drm/amdkfd: add debug queue snapshot operation

Allow the debugger to get a snapshot of a specified number of queues
containing various queue property information that is copied to the
debugger.

Since the debugger doesn't know how many queues exist at any given time,
allow the debugger to pass the requested number of snapshots as 0 to get
the actual number of potential snapshots to use for a subsequent snapshot
request for actual information.

To prevent future ABI breakage, pass in the requested entry_size.
The KFD will return it's own entry_size in case the debugger still wants
log the information in a core dump on sizing failure.

Also allow the debugger to clear exceptions when doing a snapshot.
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

@@ -3053,6 +3053,12 @@ static int kfd_ioctl_set_debug_trap(struct file *filep, struct kfd_process *p, v
 				&args->query_exception_info.info_size);
 		break;
 	case KFD_IOC_DBG_TRAP_GET_QUEUE_SNAPSHOT:
+		r = pqm_get_queue_snapshot(&target->pqm,
+				args->queue_snapshot.exception_mask,
+				(void __user *)args->queue_snapshot.snapshot_buf_ptr,
+				&args->queue_snapshot.num_queues,
+				&args->queue_snapshot.entry_size);
+		break;
 	case KFD_IOC_DBG_TRAP_GET_DEVICE_SNAPSHOT:
 		pr_warn("Debug op %i not supported yet\n", args->op);
 		r = -EACCES;

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

@@ -3041,6 +3041,42 @@ int suspend_queues(struct kfd_process *p,
 	return total_suspended;
 }
 
+static uint32_t set_queue_type_for_user(struct queue_properties *q_props)
+{
+	switch (q_props->type) {
+	case KFD_QUEUE_TYPE_COMPUTE:
+		return q_props->format == KFD_QUEUE_FORMAT_PM4
+					? KFD_IOC_QUEUE_TYPE_COMPUTE
+					: KFD_IOC_QUEUE_TYPE_COMPUTE_AQL;
+	case KFD_QUEUE_TYPE_SDMA:
+		return KFD_IOC_QUEUE_TYPE_SDMA;
+	case KFD_QUEUE_TYPE_SDMA_XGMI:
+		return KFD_IOC_QUEUE_TYPE_SDMA_XGMI;
+	default:
+		WARN_ONCE(true, "queue type not recognized!");
+		return 0xffffffff;
+	};
+}
+
+void set_queue_snapshot_entry(struct queue *q,
+			      uint64_t exception_clear_mask,
+			      struct kfd_queue_snapshot_entry *qss_entry)
+{
+	qss_entry->ring_base_address = q->properties.queue_address;
+	qss_entry->write_pointer_address = (uint64_t)q->properties.write_ptr;
+	qss_entry->read_pointer_address = (uint64_t)q->properties.read_ptr;
+	qss_entry->ctx_save_restore_address =
+				q->properties.ctx_save_restore_area_address;
+	qss_entry->ctx_save_restore_area_size =
+				q->properties.ctx_save_restore_area_size;
+	qss_entry->exception_status = q->properties.exception_status;
+	qss_entry->queue_id = q->properties.queue_id;
+	qss_entry->gpu_id = q->device->id;
+	qss_entry->ring_size = (uint32_t)q->properties.queue_size;
+	qss_entry->queue_type = set_queue_type_for_user(&q->properties);
+	q->properties.exception_status &= ~exception_clear_mask;
+}
+
 int debug_lock_and_unmap(struct device_queue_manager *dqm)
 {
 	int r;

drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h

@@ -300,6 +300,9 @@ int suspend_queues(struct kfd_process *p,
 int resume_queues(struct kfd_process *p,
 		uint32_t num_queues,
 		uint32_t *usr_queue_id_array);
+void set_queue_snapshot_entry(struct queue *q,
+			      uint64_t exception_clear_mask,
+			      struct kfd_queue_snapshot_entry *qss_entry);
 int debug_lock_and_unmap(struct device_queue_manager *dqm);
 int debug_map_and_unlock(struct device_queue_manager *dqm);
 int debug_refresh_runlist(struct device_queue_manager *dqm);

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

@@ -1355,6 +1355,11 @@ int pqm_get_wave_state(struct process_queue_manager *pqm,
 		       void __user *ctl_stack,
 		       u32 *ctl_stack_used_size,
 		       u32 *save_area_used_size);
+int pqm_get_queue_snapshot(struct process_queue_manager *pqm,
+			   uint64_t exception_clear_mask,
+			   void __user *buf,
+			   int *num_qss_entries,
+			   uint32_t *entry_size);
 
 int amdkfd_fence_wait_timeout(uint64_t *fence_addr,
 			      uint64_t fence_value,

drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c

@@ -585,6 +585,46 @@ int pqm_get_wave_state(struct process_queue_manager *pqm,
 						       save_area_used_size);
 }
 
+int pqm_get_queue_snapshot(struct process_queue_manager *pqm,
+			   uint64_t exception_clear_mask,
+			   void __user *buf,
+			   int *num_qss_entries,
+			   uint32_t *entry_size)
+{
+	struct process_queue_node *pqn;
+	struct kfd_queue_snapshot_entry src;
+	uint32_t tmp_entry_size = *entry_size, tmp_qss_entries = *num_qss_entries;
+	int r = 0;
+
+	*num_qss_entries = 0;
+	if (!(*entry_size))
+		return -EINVAL;
+
+	*entry_size = min_t(size_t, *entry_size, sizeof(struct kfd_queue_snapshot_entry));
+	mutex_lock(&pqm->process->event_mutex);
+
+	memset(&src, 0, sizeof(src));
+
+	list_for_each_entry(pqn, &pqm->queues, process_queue_list) {
+		if (!pqn->q)
+			continue;
+
+		if (*num_qss_entries < tmp_qss_entries) {
+			set_queue_snapshot_entry(pqn->q, exception_clear_mask, &src);
+
+			if (copy_to_user(buf, &src, *entry_size)) {
+				r = -EFAULT;
+				break;
+			}
+			buf += tmp_entry_size;
+		}
+		*num_qss_entries += 1;
+	}
+
+	mutex_unlock(&pqm->process->event_mutex);
+	return r;
+}
+
 static int get_queue_data_sizes(struct kfd_process_device *pdd,
 				struct queue *q,
 				uint32_t *mqd_size,