dwc3: flush the buffers before using it

In the linux kernel, non cacheable buffers are used. However in uboot
since there are no APIs to allocate non cacheable memory, all
the buffers should be flushed before using it.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/usb/dwc3/core.c

@@ -157,8 +157,8 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
 	num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
 	dwc->num_event_buffers = num;
 
-	dwc->ev_buffs = devm_kzalloc(dwc->dev, sizeof(*dwc->ev_buffs) * num,
-			GFP_KERNEL);
+	dwc->ev_buffs = memalign(CONFIG_SYS_CACHELINE_SIZE,
+				 sizeof(*dwc->ev_buffs) * num);
 	if (!dwc->ev_buffs)
 		return -ENOMEM;
 
@@ -769,11 +769,18 @@ void dwc3_uboot_exit(int index)
 void dwc3_uboot_handle_interrupt(int index)
 {
 	struct dwc3 *dwc = NULL;
+	int i;
+	struct dwc3_event_buffer *evt;
 
 	list_for_each_entry(dwc, &dwc3_list, list) {
 		if (dwc->index != index)
 			continue;
 
+		for (i = 0; i < dwc->num_event_buffers; i++) {
+			evt = dwc->ev_buffs[i];
+			dwc3_flush_cache((int)evt->buf, evt->length);
+		}
+
 		dwc3_gadget_uboot_handle_interrupt(dwc);
 		break;
 	}

drivers/usb/dwc3/ep0.c

@@ -74,6 +74,9 @@ static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
 			| DWC3_TRB_CTRL_IOC
 			| DWC3_TRB_CTRL_ISP_IMI);
 
+	dwc3_flush_cache((int)buf_dma, len);
+	dwc3_flush_cache((int)trb, sizeof(*trb));
+
 	memset(&params, 0, sizeof(params));
 	params.param0 = upper_32_bits(dwc->ep0_trb_addr);
 	params.param1 = lower_32_bits(dwc->ep0_trb_addr);
@@ -774,6 +777,8 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
 	if (!r)
 		return;
 
+	dwc3_flush_cache((int)trb, sizeof(*trb));
+
 	status = DWC3_TRB_SIZE_TRBSTS(trb->size);
 	if (status == DWC3_TRBSTS_SETUP_PENDING) {
 		dev_dbg(dwc->dev, "Setup Pending received");
@@ -795,6 +800,7 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc,
 		transfer_size += (maxp - (transfer_size % maxp));
 		transferred = min_t(u32, ur->length,
 				transfer_size - length);
+		dwc3_flush_cache((int)dwc->ep0_bounce, DWC3_EP0_BOUNCE_SIZE);
 		memcpy(ur->buf, dwc->ep0_bounce, transferred);
 	} else {
 		transferred = ur->length - length;

drivers/usb/dwc3/gadget.c

@@ -244,6 +244,7 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 
 	list_del(&req->list);
 	req->trb = NULL;
+	dwc3_flush_cache((int)req->request.dma, req->request.length);
 
 	if (req->request.status == -EINPROGRESS)
 		req->request.status = status;
@@ -769,6 +770,9 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 		trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(req->request.stream_id);
 
 	trb->ctrl |= DWC3_TRB_CTRL_HWO;
+
+	dwc3_flush_cache((int)dma, length);
+	dwc3_flush_cache((int)trb, sizeof(*trb));
 }
 
 /*
@@ -1770,6 +1774,7 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
 		slot %= DWC3_TRB_NUM;
 		trb = &dep->trb_pool[slot];
 
+		dwc3_flush_cache((int)trb, sizeof(*trb));
 		ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
 				event, status);
 		if (ret)
@@ -2583,7 +2588,8 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 		goto err1;
 	}
 
-	dwc->setup_buf = kzalloc(DWC3_EP0_BOUNCE_SIZE, GFP_KERNEL);
+	dwc->setup_buf = memalign(CONFIG_SYS_CACHELINE_SIZE,
+				  DWC3_EP0_BOUNCE_SIZE);
 	if (!dwc->setup_buf) {
 		ret = -ENOMEM;
 		goto err2;

drivers/usb/dwc3/io.h

@@ -20,6 +20,7 @@
 
 #include <asm/io.h>
 
+#define	CACHELINE_SIZE		CONFIG_SYS_CACHELINE_SIZE
 static inline u32 dwc3_readl(void __iomem *base, u32 offset)
 {
 	u32 offs = offset - DWC3_GLOBALS_REGS_START;
@@ -47,4 +48,8 @@ static inline void dwc3_writel(void __iomem *base, u32 offset, u32 value)
 	writel(value, base + offs);
 }
 
+static inline void dwc3_flush_cache(int addr, int length)
+{
+	flush_dcache_range(addr, addr + ROUND(length, CACHELINE_SIZE));
+}
 #endif /* __DRIVERS_USB_DWC3_IO_H */