usb: dwc2: host: avoid usage of dma_alloc_coherent with irqs disabled

Use Streaming DMA mappings to handle cache coherency of frame list and
descriptor list. Cache are always flushed before controller access it
or before cpu access it.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 82 insertions, 24 deletions

diff --git a/drivers/usb/dwc2/hcd_ddma.c b/drivers/usb/dwc2/hcd_ddma.c
index f98c7e91f6bc..85d7816d29f1 100644
--- a/drivers/usb/dwc2/hcd_ddma.c
+++ b/drivers/usb/dwc2/hcd_ddma.c
@@ -87,22 +87,23 @@ static u16 dwc2_frame_incr_val(struct dwc2_qh *qh)
 static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 				gfp_t flags)
 {
-	qh->desc_list = dma_alloc_coherent(hsotg->dev,
-				sizeof(struct dwc2_hcd_dma_desc) *
-				dwc2_max_desc_num(qh), &qh->desc_list_dma,
-				flags);
+	qh->desc_list_sz = sizeof(struct dwc2_hcd_dma_desc) *
+						dwc2_max_desc_num(qh);
 
+	qh->desc_list = kzalloc(qh->desc_list_sz, flags | GFP_DMA);
 	if (!qh->desc_list)
 		return -ENOMEM;
 
-	memset(qh->desc_list, 0,
-	       sizeof(struct dwc2_hcd_dma_desc) * dwc2_max_desc_num(qh));
+	qh->desc_list_dma = dma_map_single(hsotg->dev, qh->desc_list,
+					   qh->desc_list_sz,
+					   DMA_TO_DEVICE);
 
 	qh->n_bytes = kzalloc(sizeof(u32) * dwc2_max_desc_num(qh), flags);
 	if (!qh->n_bytes) {
-		dma_free_coherent(hsotg->dev, sizeof(struct dwc2_hcd_dma_desc)
-				  * dwc2_max_desc_num(qh), qh->desc_list,
-				  qh->desc_list_dma);
+		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
+				 qh->desc_list_sz,
+				 DMA_FROM_DEVICE);
+		kfree(qh->desc_list);
 		qh->desc_list = NULL;
 		return -ENOMEM;
 	}
@@ -113,9 +114,9 @@ static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 static void dwc2_desc_list_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
 {
 	if (qh->desc_list) {
-		dma_free_coherent(hsotg->dev, sizeof(struct dwc2_hcd_dma_desc)
-				  * dwc2_max_desc_num(qh), qh->desc_list,
-				  qh->desc_list_dma);
+		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
+				 qh->desc_list_sz, DMA_FROM_DEVICE);
+		kfree(qh->desc_list);
 		qh->desc_list = NULL;
 	}
 
@@ -128,21 +129,20 @@ static int dwc2_frame_list_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags)
 	if (hsotg->frame_list)
 		return 0;
 
-	hsotg->frame_list = dma_alloc_coherent(hsotg->dev,
-					       4 * FRLISTEN_64_SIZE,
-					       &hsotg->frame_list_dma,
-					       mem_flags);
+	hsotg->frame_list_sz = 4 * FRLISTEN_64_SIZE;
+	hsotg->frame_list = kzalloc(hsotg->frame_list_sz, GFP_ATOMIC | GFP_DMA);
 	if (!hsotg->frame_list)
 		return -ENOMEM;
 
-	memset(hsotg->frame_list, 0, 4 * FRLISTEN_64_SIZE);
+	hsotg->frame_list_dma = dma_map_single(hsotg->dev, hsotg->frame_list,
+					       hsotg->frame_list_sz,
+					       DMA_TO_DEVICE);
+
 	return 0;
 }
 
 static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
 {
-	u32 *frame_list;
-	dma_addr_t frame_list_dma;
 	unsigned long flags;
 
 	spin_lock_irqsave(&hsotg->lock, flags);
@@ -152,14 +152,14 @@ static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
 		return;
 	}
 
-	frame_list = hsotg->frame_list;
-	frame_list_dma = hsotg->frame_list_dma;
+	dma_unmap_single(hsotg->dev, hsotg->frame_list_dma,
+			 hsotg->frame_list_sz, DMA_FROM_DEVICE);
+
+	kfree(hsotg->frame_list);
 	hsotg->frame_list = NULL;
 
 	spin_unlock_irqrestore(&hsotg->lock, flags);
 
-	dma_free_coherent(hsotg->dev, 4 * FRLISTEN_64_SIZE, frame_list,
-			  frame_list_dma);
 }
 
 static void dwc2_per_sched_enable(struct dwc2_hsotg *hsotg, u32 fr_list_en)
@@ -249,6 +249,15 @@ static void dwc2_update_frame_list(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 		j = (j + inc) & (FRLISTEN_64_SIZE - 1);
 	} while (j != i);
 
+	/*
+	 * Sync frame list since controller will access it if periodic
+	 * channel is currently enabled.
+	 */
+	dma_sync_single_for_device(hsotg->dev,
+				   hsotg->frame_list_dma,
+				   hsotg->frame_list_sz,
+				   DMA_TO_DEVICE);
+
 	if (!enable)
 		return;
 
@@ -541,6 +550,11 @@ static void dwc2_fill_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 		dma_desc->status |= HOST_DMA_IOC;
 #endif
 
+	dma_sync_single_for_device(hsotg->dev,
+			qh->desc_list_dma +
+			(idx * sizeof(struct dwc2_hcd_dma_desc)),
+			sizeof(struct dwc2_hcd_dma_desc),
+			DMA_TO_DEVICE);
 }
 
 static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
@@ -610,6 +624,11 @@ static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 	if (qh->ntd == ntd_max) {
 		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
 		qh->desc_list[idx].status |= HOST_DMA_IOC;
+		dma_sync_single_for_device(hsotg->dev,
+					   qh->desc_list_dma + (idx *
+					   sizeof(struct dwc2_hcd_dma_desc)),
+					   sizeof(struct dwc2_hcd_dma_desc),
+					   DMA_TO_DEVICE);
 	}
 #else
 	/*
@@ -639,6 +658,11 @@ static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
 
 	qh->desc_list[idx].status |= HOST_DMA_IOC;
+	dma_sync_single_for_device(hsotg->dev,
+				   qh->desc_list_dma +
+				   (idx * sizeof(struct dwc2_hcd_dma_desc)),
+				   sizeof(struct dwc2_hcd_dma_desc),
+				   DMA_TO_DEVICE);
 #endif
 }
 
@@ -676,6 +700,12 @@ static void dwc2_fill_host_dma_desc(struct dwc2_hsotg *hsotg,
 
 	dma_desc->buf = (u32)chan->xfer_dma;
 
+	dma_sync_single_for_device(hsotg->dev,
+				   qh->desc_list_dma +
+				   (n_desc * sizeof(struct dwc2_hcd_dma_desc)),
+				   sizeof(struct dwc2_hcd_dma_desc),
+				   DMA_TO_DEVICE);
+
 	/*
 	 * Last (or only) descriptor of IN transfer with actual size less
 	 * than MaxPacket
@@ -726,6 +756,12 @@ static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 					 "set A bit in desc %d (%p)\n",
 					 n_desc - 1,
 					 &qh->desc_list[n_desc - 1]);
+				dma_sync_single_for_device(hsotg->dev,
+					qh->desc_list_dma +
+					((n_desc - 1) *
+					sizeof(struct dwc2_hcd_dma_desc)),
+					sizeof(struct dwc2_hcd_dma_desc),
+					DMA_TO_DEVICE);
 			}
 			dwc2_fill_host_dma_desc(hsotg, chan, qtd, qh, n_desc);
 			dev_vdbg(hsotg->dev,
@@ -751,10 +787,19 @@ static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 				HOST_DMA_IOC | HOST_DMA_EOL | HOST_DMA_A;
 		dev_vdbg(hsotg->dev, "set IOC/EOL/A bits in desc %d (%p)\n",
 			 n_desc - 1, &qh->desc_list[n_desc - 1]);
+		dma_sync_single_for_device(hsotg->dev,
+					   qh->desc_list_dma + (n_desc - 1) *
+					   sizeof(struct dwc2_hcd_dma_desc),
+					   sizeof(struct dwc2_hcd_dma_desc),
+					   DMA_TO_DEVICE);
 		if (n_desc > 1) {
 			qh->desc_list[0].status |= HOST_DMA_A;
 			dev_vdbg(hsotg->dev, "set A bit in desc 0 (%p)\n",
 				 &qh->desc_list[0]);
+			dma_sync_single_for_device(hsotg->dev,
+					qh->desc_list_dma,
+					sizeof(struct dwc2_hcd_dma_desc),
+					DMA_TO_DEVICE);
 		}
 		chan->ntd = n_desc;
 	}
@@ -829,7 +874,7 @@ static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 					struct dwc2_qtd *qtd,
 					struct dwc2_qh *qh, u16 idx)
 {
-	struct dwc2_hcd_dma_desc *dma_desc = &qh->desc_list[idx];
+	struct dwc2_hcd_dma_desc *dma_desc;
 	struct dwc2_hcd_iso_packet_desc *frame_desc;
 	u16 remain = 0;
 	int rc = 0;
@@ -837,6 +882,13 @@ static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 	if (!qtd->urb)
 		return -EINVAL;
 
+	dma_sync_single_for_cpu(hsotg->dev, qh->desc_list_dma + (idx *
+				sizeof(struct dwc2_hcd_dma_desc)),
+				sizeof(struct dwc2_hcd_dma_desc),
+				DMA_FROM_DEVICE);
+
+	dma_desc = &qh->desc_list[idx];
+
 	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
 	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
 	if (chan->ep_is_in)
@@ -1092,6 +1144,12 @@ static int dwc2_process_non_isoc_desc(struct dwc2_hsotg *hsotg,
 	if (!urb)
 		return -EINVAL;
 
+	dma_sync_single_for_cpu(hsotg->dev,
+				qh->desc_list_dma + (desc_num *
+				sizeof(struct dwc2_hcd_dma_desc)),
+				sizeof(struct dwc2_hcd_dma_desc),
+				DMA_FROM_DEVICE);
+
 	dma_desc = &qh->desc_list[desc_num];
 	n_bytes = qh->n_bytes[desc_num];
 	dev_vdbg(hsotg->dev,