From e81e7f9a0eb9536d5976acf5d95290338032a198 Mon Sep 17 00:00:00 2001 From: Michael Grzeschik Date: Mon, 28 Jun 2021 17:53:10 +0200 Subject: [PATCH] usb: gadget: uvc: add scatter gather support This patch adds support for scatter gather transfers. If the underlying gadgets sg_supported == true, then the videeobuf2-dma-sg is used and the encode routine maps all scatter entries to separate scatterlists for the usb gadget. When streaming 1080p with request size of 1024 times 3 bytes top shows a difference of about 6.4% CPU load applying this patch: PID USER PR NI VIRT RES %CPU %MEM TIME+ S COMMAND 64 root 0 -20 0.0m 0.0m 7.7 0.0 0:01.25 I [kworker/u5:0-uvcvideo] 83 root 0 -20 0.0m 0.0m 4.5 0.0 0:03.71 I [kworker/u5:3-uvcvideo] 307 root -51 0 0.0m 0.0m 3.8 0.0 0:01.05 S [irq/51-dwc3] vs. 64 root 0 -20 0.0m 0.0m 5.8 0.0 0:01.79 I [kworker/u5:0-uvcvideo] 306 root -51 0 0.0m 0.0m 3.2 0.0 0:01.97 S [irq/51-dwc3] 82 root 0 -20 0.0m 0.0m 0.6 0.0 0:01.86 I [kworker/u5:1-uvcvideo] Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20210628155311.16762-5-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/Kconfig | 1 + drivers/usb/gadget/function/uvc.h | 2 + drivers/usb/gadget/function/uvc_queue.c | 22 +++++++-- drivers/usb/gadget/function/uvc_queue.h | 7 ++- drivers/usb/gadget/function/uvc_video.c | 82 +++++++++++++++++++++++++++++++-- drivers/usb/gadget/function/uvc_video.h | 2 + drivers/usb/gadget/legacy/Kconfig | 1 + 7 files changed, 108 insertions(+), 9 deletions(-) diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index 2d15257..dd58094 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -450,6 +450,7 @@ config USB_CONFIGFS_F_UVC depends on USB_CONFIGFS depends on VIDEO_V4L2 depends on VIDEO_DEV + select VIDEOBUF2_DMA_SG select VIDEOBUF2_VMALLOC select USB_F_UVC help diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h index 52f8941..36b78f8 100644 --- a/drivers/usb/gadget/function/uvc.h +++ b/drivers/usb/gadget/function/uvc.h @@ -75,6 +75,8 @@ struct uvc_request { struct usb_request *req; u8 *req_buffer; struct uvc_video *video; + struct sg_table sgt; + u8 header[2]; }; struct uvc_video { diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c index ff0cc08..7d00ad7 100644 --- a/drivers/usb/gadget/function/uvc_queue.c +++ b/drivers/usb/gadget/function/uvc_queue.c @@ -17,6 +17,7 @@ #include #include +#include #include #include "uvc.h" @@ -76,7 +77,12 @@ static int uvc_buffer_prepare(struct vb2_buffer *vb) return -ENODEV; buf->state = UVC_BUF_STATE_QUEUED; - buf->mem = vb2_plane_vaddr(vb, 0); + if (queue->use_sg) { + buf->sgt = vb2_dma_sg_plane_desc(vb, 0); + buf->sg = buf->sgt->sgl; + } else { + buf->mem = vb2_plane_vaddr(vb, 0); + } buf->length = vb2_plane_size(vb, 0); if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) buf->bytesused = 0; @@ -116,9 +122,11 @@ static const struct vb2_ops uvc_queue_qops = { .wait_finish = vb2_ops_wait_finish, }; -int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, +int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2_buf_type type, struct mutex *lock) { + struct uvc_video *video = container_of(queue, struct uvc_video, queue); + struct usb_composite_dev *cdev = video->uvc->func.config->cdev; int ret; queue->queue.type = type; @@ -127,9 +135,17 @@ int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, queue->queue.buf_struct_size = sizeof(struct uvc_buffer); queue->queue.ops = &uvc_queue_qops; queue->queue.lock = lock; - queue->queue.mem_ops = &vb2_vmalloc_memops; + if (cdev->gadget->sg_supported) { + queue->queue.mem_ops = &vb2_dma_sg_memops; + queue->use_sg = 1; + } else { + queue->queue.mem_ops = &vb2_vmalloc_memops; + } + queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC | V4L2_BUF_FLAG_TSTAMP_SRC_EOF; + queue->queue.dev = dev; + ret = vb2_queue_init(&queue->queue); if (ret) return ret; diff --git a/drivers/usb/gadget/function/uvc_queue.h b/drivers/usb/gadget/function/uvc_queue.h index 2f0fff7..05360a0 100644 --- a/drivers/usb/gadget/function/uvc_queue.h +++ b/drivers/usb/gadget/function/uvc_queue.h @@ -34,6 +34,9 @@ struct uvc_buffer { enum uvc_buffer_state state; void *mem; + struct sg_table *sgt; + struct scatterlist *sg; + unsigned int offset; unsigned int length; unsigned int bytesused; }; @@ -50,6 +53,8 @@ struct uvc_video_queue { unsigned int buf_used; + bool use_sg; + spinlock_t irqlock; /* Protects flags and irqqueue */ struct list_head irqqueue; }; @@ -59,7 +64,7 @@ static inline int uvc_queue_streaming(struct uvc_video_queue *queue) return vb2_is_streaming(&queue->queue); } -int uvcg_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, +int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2_buf_type type, struct mutex *lock); void uvcg_free_buffers(struct uvc_video_queue *queue); diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c index 303cb42..2cefb8b 100644 --- a/drivers/usb/gadget/function/uvc_video.c +++ b/drivers/usb/gadget/function/uvc_video.c @@ -27,10 +27,10 @@ static int uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf, u8 *data, int len) { - data[0] = 2; + data[0] = UVCG_REQUEST_HEADER_LEN; data[1] = UVC_STREAM_EOH | video->fid; - if (buf->bytesused - video->queue.buf_used <= len - 2) + if (buf->bytesused - video->queue.buf_used <= len - UVCG_REQUEST_HEADER_LEN) data[1] |= UVC_STREAM_EOF; return 2; @@ -95,6 +95,71 @@ uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video, } static void +uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video, + struct uvc_buffer *buf) +{ + unsigned int pending = buf->bytesused - video->queue.buf_used; + struct uvc_request *ureq = req->context; + struct scatterlist *sg, *iter; + unsigned int len = video->req_size; + unsigned int sg_left, part = 0; + unsigned int i; + int ret; + + sg = ureq->sgt.sgl; + sg_init_table(sg, ureq->sgt.nents); + + /* Init the header. */ + ret = uvc_video_encode_header(video, buf, ureq->header, + video->req_size); + sg_set_buf(sg, ureq->header, UVCG_REQUEST_HEADER_LEN); + len -= ret; + + if (pending <= len) + len = pending; + + req->length = (len == pending) ? + len + UVCG_REQUEST_HEADER_LEN : video->req_size; + + /* Init the pending sgs with payload */ + sg = sg_next(sg); + + for_each_sg(sg, iter, ureq->sgt.nents - 1, i) { + if (!len || !buf->sg) + break; + + sg_left = sg_dma_len(buf->sg) - buf->offset; + part = min_t(unsigned int, len, sg_left); + + sg_set_page(iter, sg_page(buf->sg), part, buf->offset); + + if (part == sg_left) { + buf->offset = 0; + buf->sg = sg_next(buf->sg); + } else { + buf->offset += part; + } + len -= part; + } + + /* Assign the video data with header. */ + req->buf = NULL; + req->sg = ureq->sgt.sgl; + req->num_sgs = i + 1; + + req->length -= len; + video->queue.buf_used += req->length - UVCG_REQUEST_HEADER_LEN; + + if (buf->bytesused == video->queue.buf_used || !buf->sg) { + video->queue.buf_used = 0; + buf->state = UVC_BUF_STATE_DONE; + buf->offset = 0; + uvcg_queue_next_buffer(&video->queue, buf); + video->fid ^= UVC_STREAM_FID; + } +} + +static void uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, struct uvc_buffer *buf) { @@ -180,6 +245,8 @@ uvc_video_free_requests(struct uvc_video *video) if (video->ureq) { for (i = 0; i < video->uvc_num_requests; ++i) { + sg_free_table(&video->ureq[i].sgt); + if (video->ureq[i].req) { usb_ep_free_request(video->ep, video->ureq[i].req); video->ureq[i].req = NULL; @@ -233,6 +300,10 @@ uvc_video_alloc_requests(struct uvc_video *video) video->ureq[i].video = video; list_add_tail(&video->ureq[i].req->list, &video->req_free); + /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ + sg_alloc_table(&video->ureq[i].sgt, + DIV_ROUND_UP(req_size - 2, PAGE_SIZE) + 2, + GFP_KERNEL); } video->req_size = req_size; @@ -342,7 +413,8 @@ int uvcg_video_enable(struct uvc_video *video, int enable) video->encode = uvc_video_encode_bulk; video->payload_size = 0; } else - video->encode = uvc_video_encode_isoc; + video->encode = video->queue.use_sg ? + uvc_video_encode_isoc_sg : uvc_video_encode_isoc; schedule_work(&video->pump); @@ -366,8 +438,8 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) video->imagesize = 320 * 240 * 2; /* Initialize the video buffers queue. */ - uvcg_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT, - &video->mutex); + uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent, + V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex); return 0; } diff --git a/drivers/usb/gadget/function/uvc_video.h b/drivers/usb/gadget/function/uvc_video.h index 03adeef..9bf1947 100644 --- a/drivers/usb/gadget/function/uvc_video.h +++ b/drivers/usb/gadget/function/uvc_video.h @@ -12,6 +12,8 @@ #ifndef __UVC_VIDEO_H__ #define __UVC_VIDEO_H__ +#define UVCG_REQUEST_HEADER_LEN 2 + struct uvc_video; int uvcg_video_enable(struct uvc_video *video, int enable); diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig index 11dd6e8..de6668e 100644 --- a/drivers/usb/gadget/legacy/Kconfig +++ b/drivers/usb/gadget/legacy/Kconfig @@ -502,6 +502,7 @@ config USB_G_WEBCAM tristate "USB Webcam Gadget" depends on VIDEO_V4L2 select USB_LIBCOMPOSITE + select VIDEOBUF2_DMA_SG select VIDEOBUF2_VMALLOC select USB_F_UVC help -- 2.7.4