From: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
NOT FOR MERGING
@Minas: can you please test with this patch instead of the original one?
@Marek: can you please verify if null pointer bug exists in this version?
This patch adds support for transferring requests, which are
non-contiguous in physical memory, i.e. the data buffer is described by
a scatter-list. This allows transferring large requests without relying
on error-prone contiguous buffer allocations. This way of allocating
requests is already implemented in functionfs and TCM USB functions and
automatically used if UDC driver advertises scatter-gather suppport.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx>
[mszyprow: fixed null pointer issue, rewrote commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
[andrzej.p: improved handling zlps]
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx>
---
drivers/usb/dwc2/gadget.c | 107 +++++++++++++++++++++++++++-----------
1 file changed, 76 insertions(+), 31 deletions(-)
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index e15d8a462085..e76b2e040b4c 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -768,22 +768,13 @@ static u32 dwc2_gadget_get_desc_params(struct dwc2_hsotg_ep *hs_ep, u32 *mask)
return desc_size;
}
-/*
- * dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
- * @hs_ep: The endpoint
- * @dma_buff: DMA address to use
- * @len: Length of the transfer
- *
- * This function will iterate over descriptor chain and fill its entries
- * with corresponding information based on transfer data.
- */
-static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
+static void dwc2_gadget_fill_nonisoc_xfer_ddma_one(struct dwc2_hsotg_ep *hs_ep,
+ struct dwc2_dma_desc **desc,
dma_addr_t dma_buff,
- unsigned int len)
+ unsigned int len,
+ bool true_last)
{
- struct dwc2_hsotg *hsotg = hs_ep->parent;
int dir_in = hs_ep->dir_in;
- struct dwc2_dma_desc *desc = hs_ep->desc_list;
u32 mps = hs_ep->ep.maxpacket;
u32 maxsize = 0;
u32 offset = 0;
@@ -798,41 +789,82 @@ static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
hs_ep->desc_count = 1;
for (i = 0; i < hs_ep->desc_count; ++i) {
- desc->status = 0;
- desc->status |= (DEV_DMA_BUFF_STS_HBUSY
+ (*desc)->status = 0;
+ (*desc)->status |= (DEV_DMA_BUFF_STS_HBUSY
<< DEV_DMA_BUFF_STS_SHIFT);
if (len > maxsize) {
if (!hs_ep->index && !dir_in)
- desc->status |= (DEV_DMA_L | DEV_DMA_IOC);
+ (*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
- desc->status |= (maxsize <<
- DEV_DMA_NBYTES_SHIFT & mask);
- desc->buf = dma_buff + offset;
+ (*desc)->status |=
+ maxsize << DEV_DMA_NBYTES_SHIFT & mask;
+ (*desc)->buf = dma_buff + offset;
len -= maxsize;
offset += maxsize;
} else {
- desc->status |= (DEV_DMA_L | DEV_DMA_IOC);
+ if (true_last)
+ (*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
if (dir_in)
- desc->status |= (len % mps) ? DEV_DMA_SHORT :
- ((hs_ep->send_zlp) ? DEV_DMA_SHORT : 0);
- if (len > maxsize)
- dev_err(hsotg->dev, "wrong len %d\n", len);
+ (*desc)->status |= (len % mps) ? DEV_DMA_SHORT :
+ ((hs_ep->send_zlp && true_last) ?
+ DEV_DMA_SHORT : 0);
- desc->status |=
+ (*desc)->status |=
len << DEV_DMA_NBYTES_SHIFT & mask;
- desc->buf = dma_buff + offset;
+ (*desc)->buf = dma_buff + offset;
}
- desc->status &= ~DEV_DMA_BUFF_STS_MASK;
- desc->status |= (DEV_DMA_BUFF_STS_HREADY
+ (*desc)->status &= ~DEV_DMA_BUFF_STS_MASK;
+ (*desc)->status |= (DEV_DMA_BUFF_STS_HREADY
<< DEV_DMA_BUFF_STS_SHIFT);
- desc++;
+ (*desc)++;
}
}
+/*
+ * dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
+ * @hs_ep: The endpoint
+ * @ureq: Request to transfer
+ * @offset: offset in bytes
+ * @len: Length of the transfer
+ *
+ * This function will iterate over descriptor chain and fill its entries
+ * with corresponding information based on transfer data.
+ */
+static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
+ dma_addr_t dma_buff,
+ unsigned int len)
+{
+ struct usb_request *ureq = NULL;
+ struct dwc2_dma_desc *desc = hs_ep->desc_list;
+ struct scatterlist *sg;
+ int i;
+ u8 desc_count = 0;
+
+ if (hs_ep->req)
+ ureq = &hs_ep->req->req;
+
+ /* non-DMA sg buffer */
+ if (!ureq || !ureq->num_sgs) {
+ dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
+ dma_buff, len, true);
+ return;
+ }
+
+ /* DMA sg buffer */
+ for_each_sg(ureq->sg, sg, ureq->num_sgs, i) {
+ dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
+ sg_dma_address(sg) + sg->offset, sg_dma_len(sg),
+ sg_is_last(sg));
+ desc_count += hs_ep->desc_count;
+ }
+
+ hs_ep->desc_count = desc_count;
+}
+
/*
* dwc2_gadget_fill_isoc_desc - fills next isochronous descriptor in chain.
* @hs_ep: The isochronous endpoint.
@@ -944,7 +976,13 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
hs_ep->next_desc = 0;
list_for_each_entry_safe(hs_req, treq, &hs_ep->queue, queue) {
- ret = dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
+ dma_addr_t dma_addr = hs_req->req.dma;
+
+ if (hs_req->req.num_sgs) {
+ WARN_ON(hs_req->req.num_sgs > 1);
+ dma_addr = sg_dma_address(hs_req->req.sg);
+ }
+ ret = dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
hs_req->req.length);
if (ret)
break;
@@ -1399,7 +1437,13 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
*/
if (using_desc_dma(hs) && hs_ep->isochronous) {
if (hs_ep->target_frame != TARGET_FRAME_INITIAL) {
- dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma,
+ dma_addr_t dma_addr = hs_req->req.dma;
+
+ if (hs_req->req.num_sgs) {
+ WARN_ON(hs_req->req.num_sgs > 1);
+ dma_addr = sg_dma_address(hs_req->req.sg);
+ }
+ dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
hs_req->req.length);
}
return 0;
@@ -4386,6 +4430,7 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget,
hsotg->enabled = 0;
spin_unlock_irqrestore(&hsotg->lock, flags);
+ gadget->sg_supported = using_desc_dma(hsotg);
dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
return 0;
--
2.17.1
