habanalabs: Avoid using a non-initialized MMU cache mutex

The MMU cache mutex is used in the ASIC hw_init() functions, but it is
initialized only later in hl_mmu_init().
This patch prevents it by moving the initialization to the
device_early_init() function.
Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/misc/habanalabs/device.c

@@ -231,6 +231,7 @@ static int device_early_init(struct hl_device *hdev)
 
 	mutex_init(&hdev->fd_open_cnt_lock);
 	mutex_init(&hdev->send_cpu_message_lock);
+	mutex_init(&hdev->mmu_cache_lock);
 	INIT_LIST_HEAD(&hdev->hw_queues_mirror_list);
 	spin_lock_init(&hdev->hw_queues_mirror_lock);
 	atomic_set(&hdev->in_reset, 0);
@@ -260,6 +261,7 @@ static int device_early_init(struct hl_device *hdev)
  */
 static void device_early_fini(struct hl_device *hdev)
 {
+	mutex_destroy(&hdev->mmu_cache_lock);
 	mutex_destroy(&hdev->send_cpu_message_lock);
 
 	hl_cb_mgr_fini(hdev, &hdev->kernel_cb_mgr);

drivers/misc/habanalabs/mmu.c

@@ -404,15 +404,12 @@ int hl_mmu_init(struct hl_device *hdev)
 
 	/* MMU H/W init was already done in device hw_init() */
 
-	mutex_init(&hdev->mmu_cache_lock);
-
 	hdev->mmu_pgt_pool =
 			gen_pool_create(__ffs(prop->mmu_hop_table_size), -1);
 
 	if (!hdev->mmu_pgt_pool) {
 		dev_err(hdev->dev, "Failed to create page gen pool\n");
-		rc = -ENOMEM;
-		goto err_pool_create;
+		return -ENOMEM;
 	}
 
 	rc = gen_pool_add(hdev->mmu_pgt_pool, prop->mmu_pgt_addr +
@@ -436,8 +433,6 @@ int hl_mmu_init(struct hl_device *hdev)
 
 err_pool_add:
 	gen_pool_destroy(hdev->mmu_pgt_pool);
-err_pool_create:
-	mutex_destroy(&hdev->mmu_cache_lock);
 
 	return rc;
 }
@@ -459,7 +454,6 @@ void hl_mmu_fini(struct hl_device *hdev)
 
 	kvfree(hdev->mmu_shadow_hop0);
 	gen_pool_destroy(hdev->mmu_pgt_pool);
-	mutex_destroy(&hdev->mmu_cache_lock);
 
 	/* MMU H/W fini will be done in device hw_fini() */
 }