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>

3 files changed, 54 insertions, 22 deletions

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index d72557cfc052..745230d0d8b3 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/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;
 }
diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
index 6927bba86245..6ea8eb6899f4 100644
--- a/drivers/usb/dwc2/hcd_intr.c
+++ b/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;
diff --git a/drivers/usb/dwc2/hcd_queue.c b/drivers/usb/dwc2/hcd_queue.c
index 63207dc3cb22..9b5c36256627 100644
--- a/drivers/usb/dwc2/hcd_queue.c
+++ b/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);
 }