usb: dwc2: host: don't use dma_alloc_coherent with irqs disabled

Align buffer must be allocated using kmalloc since irqs are disabled.
Coherency is handled through dma_map_single which can be used with irqs
disabled.
Reviewed-by: Julius Werner <jwerner@chromium.org>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc2/hcd.c

@@ -719,9 +719,7 @@ static int dwc2_hc_setup_align_buf(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 			/* 3072 = 3 max-size Isoc packets */
 			buf_size = 3072;
 
-		qh->dw_align_buf = dma_alloc_coherent(hsotg->dev, buf_size,
-						      &qh->dw_align_buf_dma,
-						      GFP_ATOMIC);
+		qh->dw_align_buf = kmalloc(buf_size, GFP_ATOMIC | GFP_DMA);
 		if (!qh->dw_align_buf)
 			return -ENOMEM;
 		qh->dw_align_buf_size = buf_size;
@@ -746,6 +744,15 @@ static int dwc2_hc_setup_align_buf(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 		}
 	}
 
+	qh->dw_align_buf_dma = dma_map_single(hsotg->dev,
+			qh->dw_align_buf, qh->dw_align_buf_size,
+			chan->ep_is_in ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
+	if (dma_mapping_error(hsotg->dev, qh->dw_align_buf_dma)) {
+		dev_err(hsotg->dev, "can't map align_buf\n");
+		chan->align_buf = (dma_addr_t)NULL;
+		return -EINVAL;
+	}
+
 	chan->align_buf = qh->dw_align_buf_dma;
 	return 0;
 }

drivers/usb/dwc2/hcd_intr.c

@@ -466,10 +466,15 @@ static int dwc2_update_urb_state(struct dwc2_hsotg *hsotg,
 	}
 
 	/* Non DWORD-aligned buffer case handling */
-	if (chan->align_buf && xfer_length && chan->ep_is_in) {
+	if (chan->align_buf && xfer_length) {
 		dev_vdbg(hsotg->dev, "%s(): non-aligned buffer\n", __func__);
-		memcpy(urb->buf + urb->actual_length, chan->qh->dw_align_buf,
-		       xfer_length);
+		dma_unmap_single(hsotg->dev, chan->qh->dw_align_buf_dma,
+				chan->qh->dw_align_buf_size,
+				chan->ep_is_in ?
+				DMA_FROM_DEVICE : DMA_TO_DEVICE);
+		if (chan->ep_is_in)
+			memcpy(urb->buf + urb->actual_length,
+					chan->qh->dw_align_buf, xfer_length);
 	}
 
 	dev_vdbg(hsotg->dev, "urb->actual_length=%d xfer_length=%d\n",
@@ -555,13 +560,18 @@ static enum dwc2_halt_status dwc2_update_isoc_urb_state(
 					chan, chnum, qtd, halt_status, NULL);
 
 		/* Non DWORD-aligned buffer case handling */
-		if (chan->align_buf && frame_desc->actual_length &&
-		    chan->ep_is_in) {
+		if (chan->align_buf && frame_desc->actual_length) {
 			dev_vdbg(hsotg->dev, "%s(): non-aligned buffer\n",
 				 __func__);
-			memcpy(urb->buf + frame_desc->offset +
-			       qtd->isoc_split_offset, chan->qh->dw_align_buf,
-			       frame_desc->actual_length);
+			dma_unmap_single(hsotg->dev, chan->qh->dw_align_buf_dma,
+					chan->qh->dw_align_buf_size,
+					chan->ep_is_in ?
+					DMA_FROM_DEVICE : DMA_TO_DEVICE);
+			if (chan->ep_is_in)
+				memcpy(urb->buf + frame_desc->offset +
+					qtd->isoc_split_offset,
+					chan->qh->dw_align_buf,
+					frame_desc->actual_length);
 		}
 		break;
 	case DWC2_HC_XFER_FRAME_OVERRUN:
@@ -584,13 +594,18 @@ static enum dwc2_halt_status dwc2_update_isoc_urb_state(
 					chan, chnum, qtd, halt_status, NULL);
 
 		/* Non DWORD-aligned buffer case handling */
-		if (chan->align_buf && frame_desc->actual_length &&
-		    chan->ep_is_in) {
+		if (chan->align_buf && frame_desc->actual_length) {
 			dev_vdbg(hsotg->dev, "%s(): non-aligned buffer\n",
 				 __func__);
-			memcpy(urb->buf + frame_desc->offset +
-			       qtd->isoc_split_offset, chan->qh->dw_align_buf,
-			       frame_desc->actual_length);
+			dma_unmap_single(hsotg->dev, chan->qh->dw_align_buf_dma,
+					chan->qh->dw_align_buf_size,
+					chan->ep_is_in ?
+					DMA_FROM_DEVICE : DMA_TO_DEVICE);
+			if (chan->ep_is_in)
+				memcpy(urb->buf + frame_desc->offset +
+					qtd->isoc_split_offset,
+					chan->qh->dw_align_buf,
+					frame_desc->actual_length);
 		}
 
 		/* Skip whole frame */
@@ -926,6 +941,8 @@ static int dwc2_xfercomp_isoc_split_in(struct dwc2_hsotg *hsotg,
 
 	if (chan->align_buf) {
 		dev_vdbg(hsotg->dev, "%s(): non-aligned buffer\n", __func__);
+		dma_unmap_single(hsotg->dev, chan->qh->dw_align_buf_dma,
+				chan->qh->dw_align_buf_size, DMA_FROM_DEVICE);
 		memcpy(qtd->urb->buf + frame_desc->offset +
 		       qtd->isoc_split_offset, chan->qh->dw_align_buf, len);
 	}
@@ -1155,8 +1172,14 @@ static void dwc2_update_urb_state_abn(struct dwc2_hsotg *hsotg,
 	/* Non DWORD-aligned buffer case handling */
 	if (chan->align_buf && xfer_length && chan->ep_is_in) {
 		dev_vdbg(hsotg->dev, "%s(): non-aligned buffer\n", __func__);
-		memcpy(urb->buf + urb->actual_length, chan->qh->dw_align_buf,
-		       xfer_length);
+		dma_unmap_single(hsotg->dev, chan->qh->dw_align_buf_dma,
+				chan->qh->dw_align_buf_size,
+				chan->ep_is_in ?
+				DMA_FROM_DEVICE : DMA_TO_DEVICE);
+		if (chan->ep_is_in)
+			memcpy(urb->buf + urb->actual_length,
+					chan->qh->dw_align_buf,
+					xfer_length);
 	}
 
 	urb->actual_length += xfer_length;

drivers/usb/dwc2/hcd_queue.c

@@ -229,11 +229,13 @@ static struct dwc2_qh *dwc2_hcd_qh_create(struct dwc2_hsotg *hsotg,
  */
 void dwc2_hcd_qh_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
 {
-	if (hsotg->core_params->dma_desc_enable > 0)
+	if (hsotg->core_params->dma_desc_enable > 0) {
 		dwc2_hcd_qh_free_ddma(hsotg, qh);
-	else if (qh->dw_align_buf)
-		dma_free_coherent(hsotg->dev, qh->dw_align_buf_size,
-				  qh->dw_align_buf, qh->dw_align_buf_dma);
+	} else {
+		/* kfree(NULL) is safe */
+		kfree(qh->dw_align_buf);
+		qh->dw_align_buf_dma = (dma_addr_t)0;
+	}
 	kfree(qh);
 }