From 10209abe87f5ebfd482a00323f5236d6094d0865 Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Mon, 21 Jan 2019 14:44:47 +0100 Subject: [PATCH] usb: dwc2: gadget: Add scatter-gather mode 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 [mszyprow: fixed null pointer issue, rewrote commit message] Signed-off-by: Marek Szyprowski Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/gadget.c | 113 ++++++++++++++++++++++++++------------ 1 file changed, 77 insertions(+), 36 deletions(-) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index e15d8a462085..6812a8a3a98b 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; @@ -798,39 +789,77 @@ 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, + struct usb_request *ureq, + unsigned int offset, + unsigned int len) +{ + struct dwc2_dma_desc *desc = hs_ep->desc_list; + struct scatterlist *sg; + int i; + u8 desc_count = 0; + + /* non-DMA sg buffer */ + if (!ureq->num_sgs) { + dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc, + ureq->dma + offset, 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; } /* @@ -944,7 +973,13 @@ 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; @@ -1100,7 +1135,7 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg, offset = ureq->actual; /* Fill DDMA chain entries */ - dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, ureq->dma + offset, + dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, ureq, offset, length); /* write descriptor chain address to control register */ @@ -1399,7 +1434,13 @@ 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; @@ -1987,13 +2028,12 @@ static void dwc2_hsotg_program_zlp(struct dwc2_hsotg *hsotg, dev_dbg(hsotg->dev, "Receiving zero-length packet on ep%d\n", index); if (using_desc_dma(hsotg)) { - /* Not specific buffer needed for ep0 ZLP */ - dma_addr_t dma = hs_ep->desc_list_dma; - if (!index) dwc2_gadget_set_ep0_desc_chain(hsotg, hs_ep); - dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, dma, 0); + /* Not specific buffer needed for ep0 ZLP */ + dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &hs_ep->desc_list, + hs_ep->desc_list_dma, 0, true); } else { dwc2_writel(hsotg, DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) | DXEPTSIZ_XFERSIZE(0), @@ -4386,6 +4426,7 @@ 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; -- 2.20.1