drm/amdkfd: Handle remaining BUG_ONs more gracefully v2

In most cases, BUG_ONs can be replaced with WARN_ON with an error
return. In some void functions just turn them into a WARN_ON and
possibly an early exit.

v2:
* Cleaned up error handling in pm_send_unmap_queue
* Removed redundant WARN_ON in kfd_process_destroy_delayed

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

14 files changed, 84 insertions, 55 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_dbgdev.c b/drivers/gpu/drm/amd/amdkfd/kfd_dbgdev.c
index 3841cad0a290..0aa021aa0aa1 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_dbgdev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_dbgdev.c
@@ -60,7 +60,8 @@ static int dbgdev_diq_submit_ib(struct kfd_dbgdev *dbgdev,
 	unsigned int *ib_packet_buff;
 	int status;
 
-	BUG_ON(!size_in_bytes);
+	if (WARN_ON(!size_in_bytes))
+		return -EINVAL;
 
 	kq = dbgdev->kq;
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_dbgmgr.c b/drivers/gpu/drm/amd/amdkfd/kfd_dbgmgr.c
index 2d5555c5dfae..3da25f7bda6b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_dbgmgr.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_dbgmgr.c
@@ -64,7 +64,8 @@ bool kfd_dbgmgr_create(struct kfd_dbgmgr **ppmgr, struct kfd_dev *pdev)
 	enum DBGDEV_TYPE type = DBGDEV_TYPE_DIQ;
 	struct kfd_dbgmgr *new_buff;
 
-	BUG_ON(!pdev->init_complete);
+	if (WARN_ON(!pdev->init_complete))
+		return false;
 
 	new_buff = kfd_alloc_struct(new_buff);
 	if (!new_buff) {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
index 416955f7c7d4..f628ac38e0c8 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -98,7 +98,7 @@ static const struct kfd_device_info *lookup_device_info(unsigned short did)
 
 	for (i = 0; i < ARRAY_SIZE(supported_devices); i++) {
 		if (supported_devices[i].did == did) {
-			BUG_ON(!supported_devices[i].device_info);
+			WARN_ON(!supported_devices[i].device_info);
 			return supported_devices[i].device_info;
 		}
 	}
@@ -212,9 +212,8 @@ static int iommu_invalid_ppr_cb(struct pci_dev *pdev, int pasid,
 			flags);
 
 	dev = kfd_device_by_pci_dev(pdev);
-	BUG_ON(!dev);
-
-	kfd_signal_iommu_event(dev, pasid, address,
+	if (!WARN_ON(!dev))
+		kfd_signal_iommu_event(dev, pasid, address,
 			flags & PPR_FAULT_WRITE, flags & PPR_FAULT_EXEC);
 
 	return AMD_IOMMU_INV_PRI_RSP_INVALID;
@@ -397,9 +396,12 @@ static int kfd_gtt_sa_init(struct kfd_dev *kfd, unsigned int buf_size,
 {
 	unsigned int num_of_longs;
 
-	BUG_ON(buf_size < chunk_size);
-	BUG_ON(buf_size == 0);
-	BUG_ON(chunk_size == 0);
+	if (WARN_ON(buf_size < chunk_size))
+		return -EINVAL;
+	if (WARN_ON(buf_size == 0))
+		return -EINVAL;
+	if (WARN_ON(chunk_size == 0))
+		return -EINVAL;
 
 	kfd->gtt_sa_chunk_size = chunk_size;
 	kfd->gtt_sa_num_of_chunks = buf_size / chunk_size;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 2486dfb5b17f..e553c5e45264 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -388,7 +388,8 @@ static struct mqd_manager *get_mqd_manager_nocpsch(
 {
 	struct mqd_manager *mqd;
 
-	BUG_ON(type >= KFD_MQD_TYPE_MAX);
+	if (WARN_ON(type >= KFD_MQD_TYPE_MAX))
+		return NULL;
 
 	pr_debug("mqd type %d\n", type);
 
@@ -513,7 +514,7 @@ static void uninitialize_nocpsch(struct device_queue_manager *dqm)
 {
 	int i;
 
-	BUG_ON(dqm->queue_count > 0 || dqm->processes_count > 0);
+	WARN_ON(dqm->queue_count > 0 || dqm->processes_count > 0);
 
 	kfree(dqm->allocated_queues);
 	for (i = 0 ; i < KFD_MQD_TYPE_MAX ; i++)
@@ -1129,8 +1130,8 @@ struct device_queue_manager *device_queue_manager_init(struct kfd_dev *dev)
 		dqm->ops.set_cache_memory_policy = set_cache_memory_policy;
 		break;
 	default:
-		BUG();
-		break;
+		pr_err("Invalid scheduling policy %d\n", sched_policy);
+		goto out_free;
 	}
 
 	switch (dev->device_info->asic_family) {
@@ -1143,12 +1144,12 @@ struct device_queue_manager *device_queue_manager_init(struct kfd_dev *dev)
 		break;
 	}
 
-	if (dqm->ops.initialize(dqm)) {
-		kfree(dqm);
-		return NULL;
-	}
+	if (!dqm->ops.initialize(dqm))
+		return dqm;
 
-	return dqm;
+out_free:
+	kfree(dqm);
+	return NULL;
 }
 
 void device_queue_manager_uninit(struct device_queue_manager *dqm)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_cik.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_cik.c
index 43194b43eea4..fadc56a8be71 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_cik.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_cik.c
@@ -65,7 +65,7 @@ static uint32_t compute_sh_mem_bases_64bit(unsigned int top_address_nybble)
 	 * for LDS/Scratch and GPUVM.
 	 */
 
-	BUG_ON((top_address_nybble & 1) || top_address_nybble > 0xE ||
+	WARN_ON((top_address_nybble & 1) || top_address_nybble > 0xE ||
 		top_address_nybble == 0);
 
 	return PRIVATE_BASE(top_address_nybble << 12) |
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_vi.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_vi.c
index 47ef910b1663..15e81ae9d2f4 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_vi.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager_vi.c
@@ -67,7 +67,7 @@ static uint32_t compute_sh_mem_bases_64bit(unsigned int top_address_nybble)
 	 * for LDS/Scratch and GPUVM.
 	 */
 
-	BUG_ON((top_address_nybble & 1) || top_address_nybble > 0xE ||
+	WARN_ON((top_address_nybble & 1) || top_address_nybble > 0xE ||
 		top_address_nybble == 0);
 
 	return top_address_nybble << 12 |
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c b/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
index 970bc07ac370..0e4d4a98dc2b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
@@ -41,7 +41,8 @@ static bool initialize(struct kernel_queue *kq, struct kfd_dev *dev,
 	int retval;
 	union PM4_MES_TYPE_3_HEADER nop;
 
-	BUG_ON(type != KFD_QUEUE_TYPE_DIQ && type != KFD_QUEUE_TYPE_HIQ);
+	if (WARN_ON(type != KFD_QUEUE_TYPE_DIQ && type != KFD_QUEUE_TYPE_HIQ))
+		return false;
 
 	pr_debug("Initializing queue type %d size %d\n", KFD_QUEUE_TYPE_HIQ,
 			queue_size);
@@ -62,8 +63,8 @@ static bool initialize(struct kernel_queue *kq, struct kfd_dev *dev,
 						KFD_MQD_TYPE_HIQ);
 		break;
 	default:
-		BUG();
-		break;
+		pr_err("Invalid queue type %d\n", type);
+		return false;
 	}
 
 	if (!kq->mqd)
@@ -305,6 +306,7 @@ void kernel_queue_uninit(struct kernel_queue *kq)
 	kfree(kq);
 }
 
+/* FIXME: Can this test be removed? */
 static __attribute__((unused)) void test_kq(struct kfd_dev *dev)
 {
 	struct kernel_queue *kq;
@@ -314,10 +316,18 @@ static __attribute__((unused)) void test_kq(struct kfd_dev *dev)
 	pr_err("Starting kernel queue test\n");
 
 	kq = kernel_queue_init(dev, KFD_QUEUE_TYPE_HIQ);
-	BUG_ON(!kq);
+	if (unlikely(!kq)) {
+		pr_err("  Failed to initialize HIQ\n");
+		pr_err("Kernel queue test failed\n");
+		return;
+	}
 
 	retval = kq->ops.acquire_packet_buffer(kq, 5, &buffer);
-	BUG_ON(retval != 0);
+	if (unlikely(retval != 0)) {
+		pr_err("  Failed to acquire packet buffer\n");
+		pr_err("Kernel queue test failed\n");
+		return;
+	}
 	for (i = 0; i < 5; i++)
 		buffer[i] = kq->nop_packet;
 	kq->ops.submit_packet(kq);
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_cik.c b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_cik.c
index a11477dc1047..7e0ec6bb1637 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_cik.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_cik.c
@@ -387,7 +387,8 @@ struct mqd_manager *mqd_manager_init_cik(enum KFD_MQD_TYPE type,
 {
 	struct mqd_manager *mqd;
 
-	BUG_ON(type >= KFD_MQD_TYPE_MAX);
+	if (WARN_ON(type >= KFD_MQD_TYPE_MAX))
+		return NULL;
 
 	mqd = kzalloc(sizeof(*mqd), GFP_KERNEL);
 	if (!mqd)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c
index d638c2c92234..f4c8c2324d77 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c
@@ -233,7 +233,8 @@ struct mqd_manager *mqd_manager_init_vi(enum KFD_MQD_TYPE type,
 {
 	struct mqd_manager *mqd;
 
-	BUG_ON(type >= KFD_MQD_TYPE_MAX);
+	if (WARN_ON(type >= KFD_MQD_TYPE_MAX))
+		return NULL;
 
 	mqd = kzalloc(sizeof(*mqd), GFP_KERNEL);
 	if (!mqd)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
index aacd5a3d92b7..0816d11e469d 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
@@ -35,7 +35,8 @@ static inline void inc_wptr(unsigned int *wptr, unsigned int increment_bytes,
 {
 	unsigned int temp = *wptr + increment_bytes / sizeof(uint32_t);
 
-	BUG_ON((temp * sizeof(uint32_t)) > buffer_size_bytes);
+	WARN((temp * sizeof(uint32_t)) > buffer_size_bytes,
+	     "Runlist IB overflow");
 	*wptr = temp;
 }
 
@@ -94,7 +95,8 @@ static int pm_allocate_runlist_ib(struct packet_manager *pm,
 {
 	int retval;
 
-	BUG_ON(pm->allocated);
+	if (WARN_ON(pm->allocated))
+		return -EINVAL;
 
 	pm_calc_rlib_size(pm, rl_buffer_size, is_over_subscription);
 
@@ -119,7 +121,8 @@ static int pm_create_runlist(struct packet_manager *pm, uint32_t *buffer,
 {
 	struct pm4_runlist *packet;
 
-	BUG_ON(!ib);
+	if (WARN_ON(!ib))
+		return -EFAULT;
 
 	packet = (struct pm4_runlist *)buffer;
 
@@ -211,9 +214,8 @@ static int pm_create_map_queue_vi(struct packet_manager *pm, uint32_t *buffer,
 		use_static = false; /* no static queues under SDMA */
 		break;
 	default:
-		pr_err("queue type %d\n", q->properties.type);
-		BUG();
-		break;
+		WARN(1, "queue type %d", q->properties.type);
+		return -EINVAL;
 	}
 	packet->bitfields3.doorbell_offset =
 			q->properties.doorbell_off;
@@ -266,8 +268,8 @@ static int pm_create_map_queue(struct packet_manager *pm, uint32_t *buffer,
 		use_static = false; /* no static queues under SDMA */
 		break;
 	default:
-		BUG();
-		break;
+		WARN(1, "queue type %d", q->properties.type);
+		return -EINVAL;
 	}
 
 	packet->mes_map_queues_ordinals[0].bitfields3.doorbell_offset =
@@ -392,14 +394,16 @@ static int pm_create_runlist_ib(struct packet_manager *pm,
 	pr_debug("Finished map process and queues to runlist\n");
 
 	if (is_over_subscription)
-		pm_create_runlist(pm, &rl_buffer[rl_wptr], *rl_gpu_addr,
-				alloc_size_bytes / sizeof(uint32_t), true);
+		retval = pm_create_runlist(pm, &rl_buffer[rl_wptr],
+					*rl_gpu_addr,
+					alloc_size_bytes / sizeof(uint32_t),
+					true);
 
 	for (i = 0; i < alloc_size_bytes / sizeof(uint32_t); i++)
 		pr_debug("0x%2X ", rl_buffer[i]);
 	pr_debug("\n");
 
-	return 0;
+	return retval;
 }
 
 int pm_init(struct packet_manager *pm, struct device_queue_manager *dqm)
@@ -512,7 +516,8 @@ int pm_send_query_status(struct packet_manager *pm, uint64_t fence_address,
 	int retval;
 	struct pm4_query_status *packet;
 
-	BUG_ON(!fence_address);
+	if (WARN_ON(!fence_address))
+		return -EFAULT;
 
 	mutex_lock(&pm->lock);
 	retval = pm->priv_queue->ops.acquire_packet_buffer(
@@ -577,8 +582,9 @@ int pm_send_unmap_queue(struct packet_manager *pm, enum kfd_queue_type type,
 			engine_sel__mes_unmap_queues__sdma0 + sdma_engine;
 		break;
 	default:
-		BUG();
-		break;
+		WARN(1, "queue type %d", type);
+		retval = -EINVAL;
+		goto err_invalid;
 	}
 
 	if (reset)
@@ -610,12 +616,18 @@ int pm_send_unmap_queue(struct packet_manager *pm, enum kfd_queue_type type,
 				queue_sel__mes_unmap_queues__perform_request_on_dynamic_queues_only;
 		break;
 	default:
-		BUG();
-		break;
+		WARN(1, "filter %d", mode);
+		retval = -EINVAL;
+		goto err_invalid;
 	}
 
 	pm->priv_queue->ops.submit_packet(pm->priv_queue);
 
+	mutex_unlock(&pm->lock);
+	return 0;
+
+err_invalid:
+	pm->priv_queue->ops.rollback_packet(pm->priv_queue);
 err_acquire_packet_buffer:
 	mutex_unlock(&pm->lock);
 	return retval;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
index b3f7d431b9a6..1e06de0bc673 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
@@ -92,6 +92,6 @@ unsigned int kfd_pasid_alloc(void)
 
 void kfd_pasid_free(unsigned int pasid)
 {
-	BUG_ON(pasid == 0 || pasid >= pasid_limit);
-	clear_bit(pasid, pasid_bitmap);
+	if (!WARN_ON(pasid == 0 || pasid >= pasid_limit))
+		clear_bit(pasid, pasid_bitmap);
 }
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index d030d76cef46..c74cf22a1ed9 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -79,8 +79,6 @@ struct kfd_process *kfd_create_process(const struct task_struct *thread)
 {
 	struct kfd_process *process;
 
-	BUG_ON(!kfd_process_wq);
-
 	if (!thread->mm)
 		return ERR_PTR(-EINVAL);
 
@@ -202,10 +200,8 @@ static void kfd_process_destroy_delayed(struct rcu_head *rcu)
 	struct kfd_process_release_work *work;
 	struct kfd_process *p;
 
-	BUG_ON(!kfd_process_wq);
-
 	p = container_of(rcu, struct kfd_process, rcu);
-	BUG_ON(atomic_read(&p->mm->mm_count) <= 0);
+	WARN_ON(atomic_read(&p->mm->mm_count) <= 0);
 
 	mmdrop(p->mm);
 
@@ -229,7 +225,8 @@ static void kfd_process_notifier_release(struct mmu_notifier *mn,
 	 * mmu_notifier srcu is read locked
 	 */
 	p = container_of(mn, struct kfd_process, mmu_notifier);
-	BUG_ON(p->mm != mm);
+	if (WARN_ON(p->mm != mm))
+		return;
 
 	mutex_lock(&kfd_processes_mutex);
 	hash_del_rcu(&p->kfd_processes);
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
index f6ecdffbd415..1cae95e2b13a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -218,8 +218,8 @@ int pqm_create_queue(struct process_queue_manager *pqm,
 							kq, &pdd->qpd);
 		break;
 	default:
-		BUG();
-		break;
+		WARN(1, "Invalid queue type %d", type);
+		retval = -EINVAL;
 	}
 
 	if (retval != 0) {
@@ -272,7 +272,8 @@ int pqm_destroy_queue(struct process_queue_manager *pqm, unsigned int qid)
 		dev = pqn->kq->dev;
 	if (pqn->q)
 		dev = pqn->q->device;
-	BUG_ON(!dev);
+	if (WARN_ON(!dev))
+		return -ENODEV;
 
 	pdd = kfd_get_process_device_data(dev, pqm->process);
 	if (!pdd) {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index e5486f494c47..19ce59028d6b 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -799,10 +799,12 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 	int ret;
 	uint32_t i;
 
+	if (WARN_ON(dev->kobj_node))
+		return -EEXIST;
+
 	/*
 	 * Creating the sysfs folders
 	 */
-	BUG_ON(dev->kobj_node);
 	dev->kobj_node = kfd_alloc_struct(dev->kobj_node);
 	if (!dev->kobj_node)
 		return -ENOMEM;