usb: dwc3: ep0: use immediate SETUP on TRB

If we pass TRB's own address on bpl/bph fields, we can get our SETUP
packet as immediate data on the TRB itself, without having to allocate
extra memory for it.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.h

@@ -760,12 +760,10 @@ struct dwc3_scratchpad_array {
 
 /**
  * struct dwc3 - representation of our controller
- * @ctrl_req: usb control request which is used for ep0
  * @ep0_trb: trb which is used for the ctrl_req
  * @ep0_bounce: bounce buffer for ep0
  * @zlp_buf: used when request->zero is set
  * @setup_buf: used while precessing STD USB requests
- * @ctrl_req_addr: dma address of ctrl_req
  * @ep0_trb: dma address of ep0_trb
  * @ep0_usb_req: dummy req used while handling STD USB requests
  * @ep0_bounce_addr: dma address of ep0_bounce
@@ -859,14 +857,12 @@ struct dwc3_scratchpad_array {
  *                 increments or 0 to disable.
  */
 struct dwc3 {
-	struct usb_ctrlrequest	*ctrl_req;
 	struct dwc3_trb		*ep0_trb;
 	void			*bounce;
 	void			*ep0_bounce;
 	void			*zlp_buf;
 	void			*scratchbuf;
 	u8			*setup_buf;
-	dma_addr_t		ctrl_req_addr;
 	dma_addr_t		ep0_trb_addr;
 	dma_addr_t		bounce_addr;
 	dma_addr_t		ep0_bounce_addr;

drivers/usb/dwc3/ep0.c

@@ -283,7 +283,7 @@ void dwc3_ep0_out_start(struct dwc3 *dwc)
 
 	complete(&dwc->ep0_in_setup);
 
-	dwc3_ep0_prepare_one_trb(dwc, 0, dwc->ctrl_req_addr, 8,
+	dwc3_ep0_prepare_one_trb(dwc, 0, dwc->ep0_trb_addr, 8,
 			DWC3_TRBCTL_CONTROL_SETUP, false);
 	ret = dwc3_ep0_start_trans(dwc, 0);
 	WARN_ON(ret < 0);
@@ -794,7 +794,7 @@ static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
 static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
 		const struct dwc3_event_depevt *event)
 {
-	struct usb_ctrlrequest *ctrl = dwc->ctrl_req;
+	struct usb_ctrlrequest *ctrl = (void *) dwc->ep0_trb;
 	int ret = -EINVAL;
 	u32 len;
 
@@ -916,7 +916,7 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
 
 			dwc->ep0_next_event = DWC3_EP0_COMPLETE;
 
-			dwc3_ep0_prepare_one_trb(dwc, epnum, dwc->ctrl_req_addr,
+			dwc3_ep0_prepare_one_trb(dwc, epnum, dwc->ep0_trb_addr,
 					0, DWC3_TRBCTL_CONTROL_DATA, false);
 			ret = dwc3_ep0_start_trans(dwc, epnum);
 			WARN_ON(ret < 0);
@@ -997,8 +997,9 @@ static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
 	req->direction = !!dep->number;
 
 	if (req->request.length == 0) {
+
 		dwc3_ep0_prepare_one_trb(dwc, dep->number,
-				dwc->ctrl_req_addr, 0,
+				dwc->ep0_trb_addr, 0,
 				DWC3_TRBCTL_CONTROL_DATA, false);
 		ret = dwc3_ep0_start_trans(dwc, dep->number);
 	} else if (!IS_ALIGNED(req->request.length, dep->endpoint.maxpacket)
@@ -1056,7 +1057,7 @@ static int dwc3_ep0_start_control_status(struct dwc3_ep *dep)
 		: DWC3_TRBCTL_CONTROL_STATUS2;
 
 	dwc3_ep0_prepare_one_trb(dwc, dep->number,
-			dwc->ctrl_req_addr, 0, type, false);
+			dwc->ep0_trb_addr, 0, type, false);
 	return dwc3_ep0_start_trans(dwc, dep->number);
 }
 

drivers/usb/dwc3/gadget.c

@@ -3144,27 +3144,19 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 
 	dwc->irq_gadget = irq;
 
-	dwc->ctrl_req = dma_alloc_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			&dwc->ctrl_req_addr, GFP_KERNEL);
-	if (!dwc->ctrl_req) {
-		dev_err(dwc->dev, "failed to allocate ctrl request\n");
-		ret = -ENOMEM;
-		goto err0;
-	}
-
 	dwc->ep0_trb = dma_alloc_coherent(dwc->sysdev,
 					  sizeof(*dwc->ep0_trb) * 2,
 					  &dwc->ep0_trb_addr, GFP_KERNEL);
 	if (!dwc->ep0_trb) {
 		dev_err(dwc->dev, "failed to allocate ep0 trb\n");
 		ret = -ENOMEM;
-		goto err1;
+		goto err0;
 	}
 
 	dwc->setup_buf = kzalloc(DWC3_EP0_BOUNCE_SIZE, GFP_KERNEL);
 	if (!dwc->setup_buf) {
 		ret = -ENOMEM;
-		goto err2;
+		goto err1;
 	}
 
 	dwc->ep0_bounce = dma_alloc_coherent(dwc->sysdev,
@@ -3173,20 +3165,20 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 	if (!dwc->ep0_bounce) {
 		dev_err(dwc->dev, "failed to allocate ep0 bounce buffer\n");
 		ret = -ENOMEM;
-		goto err3;
+		goto err2;
 	}
 
 	dwc->zlp_buf = kzalloc(DWC3_ZLP_BUF_SIZE, GFP_KERNEL);
 	if (!dwc->zlp_buf) {
 		ret = -ENOMEM;
-		goto err4;
+		goto err3;
 	}
 
 	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
 			&dwc->bounce_addr, GFP_KERNEL);
 	if (!dwc->bounce) {
 		ret = -ENOMEM;
-		goto err5;
+		goto err4;
 	}
 
 	init_completion(&dwc->ep0_in_setup);
@@ -3226,38 +3218,34 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 
 	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
 	if (ret)
-		goto err6;
+		goto err5;
 
 	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
 	if (ret) {
 		dev_err(dwc->dev, "failed to register udc\n");
-		goto err6;
+		goto err5;
 	}
 
 	return 0;
-err6:
+err5:
 	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
 			dwc->bounce_addr);
 
-err5:
+err4:
 	kfree(dwc->zlp_buf);
 
-err4:
+err3:
 	dwc3_gadget_free_endpoints(dwc);
 	dma_free_coherent(dwc->sysdev, DWC3_EP0_BOUNCE_SIZE,
 			dwc->ep0_bounce, dwc->ep0_bounce_addr);
 
-err3:
+err2:
 	kfree(dwc->setup_buf);
 
-err2:
+err1:
 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
 
-err1:
-	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			dwc->ctrl_req, dwc->ctrl_req_addr);
-
 err0:
 	return ret;
 }
@@ -3280,9 +3268,6 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 
 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
-
-	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ctrl_req),
-			dwc->ctrl_req, dwc->ctrl_req_addr);
 }
 
 int dwc3_gadget_suspend(struct dwc3 *dwc)