staging: r8188eu: remove _rtw_mutex_{init,free}

While testing Fabio's patch I hit lockdep warning about possible
deadlock:

[  252.063305] WARNING: possible recursive locking detected
[  252.063642] 5.14.0+ #9 Tainted: G         C
[  252.063946] --------------------------------------------
[  252.064282] ip/335 is trying to acquire lock:
[  252.064560] ffff888009ebad28 (pmutex){+.+.}-{4:4}, at: usbctrl_vendorreq+0xc5/0x4a0 [r8188eu]
[  252.065168]
[  252.065168] but task is already holding lock:
[  252.065536] ffffffffc021b3b8 (pmutex){+.+.}-{4:4}, at:  netdev_open+0x3a/0x5f [r8188eu]
[  252.066085]
[  252.066085] other info that might help us debug this:
[  252.066494]  Possible unsafe locking scenario:
[  252.066494]
[  252.066866]        CPU0
[  252.067025]        ----
[  252.067184]   lock(pmutex);
[  252.067367]   lock(pmutex);

There is one problem with this warning: there is no pmutex in this
driver, *BUT* all mutexes are initialized via private _rtw_mutex_init
API, which had struct mutex *pmutex argument.

So, all mutexes in this driver had same name in lockdep map. Of course,
lockdep will complain about any nested locking.

Fix it by open-coding _rtw_mutex_{init,free} wrappers, because we do not
need them at all.

Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20210904124747.30050-1-paskripkin@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_sreset.c

@@ -8,7 +8,7 @@ void sreset_init_value(struct adapter *padapter)
 	struct hal_data_8188e	*pHalData = GET_HAL_DATA(padapter);
 	struct sreset_priv *psrtpriv = &pHalData->srestpriv;
 
-	_rtw_mutex_init(&psrtpriv->silentreset_mutex);
+	mutex_init(&psrtpriv->silentreset_mutex);
 	psrtpriv->silent_reset_inprogress = false;
 	psrtpriv->wifi_error_status = WIFI_STATUS_SUCCESS;
 	psrtpriv->last_tx_time = 0;

drivers/staging/r8188eu/core/rtw_xmit.c

@@ -196,7 +196,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 	pxmitpriv->voq_cnt = 0;
 
 	pxmitpriv->ack_tx = false;
-	_rtw_mutex_init(&pxmitpriv->ack_tx_mutex);
+	mutex_init(&pxmitpriv->ack_tx_mutex);
 	rtw_sctx_init(&pxmitpriv->ack_tx_ops, 0);
 
 	rtw_hal_init_xmit_priv(padapter);
@@ -243,7 +243,7 @@ void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv)
 
 	rtw_free_hwxmits(padapter);
 
-	_rtw_mutex_free(&pxmitpriv->ack_tx_mutex);
+	mutex_destroy(&pxmitpriv->ack_tx_mutex);
 }
 
 static void update_attrib_vcs_info(struct adapter *padapter, struct xmit_frame *pxmitframe)

drivers/staging/r8188eu/include/osdep_service.h

@@ -155,8 +155,6 @@ extern unsigned char RSN_TKIP_CIPHER[4];
 void *rtw_malloc2d(int h, int w, int size);
 
 u32  _rtw_down_sema(struct semaphore *sema);
-void _rtw_mutex_init(struct mutex *pmutex);
-void _rtw_mutex_free(struct mutex *pmutex);
 
 void _rtw_init_queue(struct __queue *pqueue);
 

drivers/staging/r8188eu/os_dep/osdep_service.c

@@ -67,16 +67,6 @@ u32 _rtw_down_sema(struct semaphore *sema)
 		return _SUCCESS;
 }
 
-void	_rtw_mutex_init(struct mutex *pmutex)
-{
-	mutex_init(pmutex);
-}
-
-void	_rtw_mutex_free(struct mutex *pmutex)
-{
-	mutex_destroy(pmutex);
-}
-
 void	_rtw_init_queue(struct __queue *pqueue)
 {
 	INIT_LIST_HEAD(&pqueue->queue);

drivers/staging/r8188eu/os_dep/usb_intf.c

@@ -117,7 +117,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 {
 	u8 rst = _SUCCESS;
 
-	_rtw_mutex_init(&dvobj->usb_vendor_req_mutex);
+	mutex_init(&dvobj->usb_vendor_req_mutex);
 
 	dvobj->usb_alloc_vendor_req_buf = kzalloc(MAX_USB_IO_CTL_SIZE, GFP_KERNEL);
 	if (!dvobj->usb_alloc_vendor_req_buf) {
@@ -133,7 +133,7 @@ static u8 rtw_init_intf_priv(struct dvobj_priv *dvobj)
 static void rtw_deinit_intf_priv(struct dvobj_priv *dvobj)
 {
 	kfree(dvobj->usb_alloc_vendor_req_buf);
-	_rtw_mutex_free(&dvobj->usb_vendor_req_mutex);
+	mutex_destroy(&dvobj->usb_vendor_req_mutex);
 }
 
 static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
@@ -758,7 +758,7 @@ static int __init rtw_drv_entry(void)
 {
 	DBG_88E(DRV_NAME " driver version=%s\n", DRIVERVERSION);
 
-	_rtw_mutex_init(&usb_drv->hw_init_mutex);
+	mutex_init(&usb_drv->hw_init_mutex);
 
 	usb_drv->drv_registered = true;
 	return usb_register(&usb_drv->usbdrv);
@@ -771,7 +771,7 @@ static void __exit rtw_drv_halt(void)
 	usb_drv->drv_registered = false;
 	usb_deregister(&usb_drv->usbdrv);
 
-	_rtw_mutex_free(&usb_drv->hw_init_mutex);
+	mutex_destroy(&usb_drv->hw_init_mutex);
 	DBG_88E("-rtw_drv_halt\n");
 }