Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp871230pxf; Thu, 11 Mar 2021 17:46:24 -0800 (PST) X-Google-Smtp-Source: ABdhPJxXI3GX5r6+KnU/ravWM1CppapcYsi0Ynis5yJ6vOQeKbPtwIGLUAIG2Sye3eaGLCXXjBaY X-Received: by 2002:a50:e0c3:: with SMTP id j3mr11779924edl.32.1615513584193; Thu, 11 Mar 2021 17:46:24 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1615513584; cv=none; d=google.com; s=arc-20160816; b=eWFs2vnANpTsXrje7zsdWwmThicnJY76jQoulCVmUjZ1U3Mvo+8QpGu4fwoi82yvLm ZjSJRVFC+CzITyjGftZnC9z3Yx50W8QzF8BDdNDmm0YFwRXVdI+gTsfqcWW+85A8LK7H ivhTNYCpGOo+uLundIuArf2B7H494VChYc/D0xsgmy9nxog/E32lCUabS1o577m4ThXU kA8wLAvxErp10FOZiG7PH/7r/nfAdK8JQCr299aWtRQUKTE2nmdzSgXi1+n1ekqK5wpm LC+gAwF/vlZQw4msw0kb1IYsw/5J/5yAd73JAunUZWp5UwqXLSscv9aXT8+J3acxR65l bvhQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=NYdo55zZbzrE0ATbAu5J6de+OxklvSMLw8T9P9sLEIc=; b=ZjgUiv43K/KEPvc5zvuHl/UcOjRLaWIY53hvIzSSwCES5SKDHJIMlaYRbAlUKQVune i+3jdtXSGiyeSgj/5gTFu3OYx1k9EfC3FKvs3SFISNAIPCLTRsKX/zmcD83dZlkXOL3p qZo9k2yNzWtCi7cL+5IN7T6UDkD0Cq3qqoZjuig3eEVnaP0Bo0vLaS9fwv3uPKfBGlKE WdPcXLlxiwGWibz87f4gjQTOpUjCKXEwWA7Kesaxyy+9pS+WLQJOii2grYxAM/beRPqt t5CnVzj3c4vQa6nxm8jScfoEAUSqoCd0Sv+8RMkQynwhLSGswRnLIGnoUnKC46aS1ca/ /v3w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass (test mode) header.i=@ideasonboard.com header.s=mail header.b=twFyMFNC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id b14si2959577ede.310.2021.03.11.17.46.01; Thu, 11 Mar 2021 17:46:24 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass (test mode) header.i=@ideasonboard.com header.s=mail header.b=twFyMFNC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231269AbhCLBmv (ORCPT + 99 others); Thu, 11 Mar 2021 20:42:51 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:33846 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231229AbhCLBmt (ORCPT ); Thu, 11 Mar 2021 20:42:49 -0500 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C88A388F; Fri, 12 Mar 2021 02:42:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1615513368; bh=LTIaTV7mffTrdyRJC8ui13p8XsUlKMW/n9oF3otuqpM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=twFyMFNC1TPi99RCmuMG60hIhZBUNFqP+kTmzPDRlDoILwJdd6pp93iz70HVZEl4D d/axZoD4Dcg3V8JpNEzCjhlDCbZTz59IOHkaIGLD36kdz/0TOxBrYsl7RGDKejDpHF AD5IZiyIC+GwX96TPavxtcj1h2JFv+a3o14vjIgE= Date: Fri, 12 Mar 2021 03:42:13 +0200 From: Laurent Pinchart To: Christoph Hellwig Cc: Mauro Carvalho Chehab , Marek Szyprowski , Tomasz Figa , Ricardo Ribalda , Sergey Senozhatsky , iommu@lists.linux-foundation.org, Robin Murphy , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 6/6] media: uvcvideo: Use dma_alloc_noncontiguos API Message-ID: References: <20210301085236.947011-1-hch@lst.de> <20210301085236.947011-7-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210301085236.947011-7-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph and Ricardo, Thank you for the patch. On Mon, Mar 01, 2021 at 09:52:36AM +0100, Christoph Hellwig wrote: > From: Ricardo Ribalda > > On architectures where the is no coherent caching such as ARM use the s/the is/there is/ > dma_alloc_noncontiguos API and handle manually the cache flushing using s/dma_alloc_noncontiguos/dma_alloc_noncontiguous/ (and in the subject line too) > dma_sync_sgtable(). > > With this patch on the affected architectures we can measure up to 20x > performance improvement in uvc_video_copy_data_work(). > > Eg: aarch64 with an external usb camera > > NON_CONTIGUOUS > frames: 999 > packets: 999 > empty: 0 (0 %) > errors: 0 > invalid: 0 > pts: 0 early, 0 initial, 999 ok > scr: 0 count ok, 0 diff ok > sof: 2048 <= sof <= 0, freq 0.000 kHz > bytes 67034480 : duration 33303 > FPS: 29.99 > URB: 523446/4993 uS/qty: 104.836 avg 132.532 std 13.230 min 831.094 max (uS) > header: 76564/4993 uS/qty: 15.334 avg 15.229 std 3.438 min 186.875 max (uS) > latency: 468945/4992 uS/qty: 93.939 avg 132.577 std 9.531 min 824.010 max (uS) > decode: 54161/4993 uS/qty: 10.847 avg 6.313 std 1.614 min 111.458 max (uS) > raw decode speed: 9.931 Gbits/s > raw URB handling speed: 1.025 Gbits/s > throughput: 16.102 Mbits/s > URB decode CPU usage 0.162600 % > > COHERENT > frames: 999 > packets: 999 > empty: 0 (0 %) > errors: 0 > invalid: 0 > pts: 0 early, 0 initial, 999 ok > scr: 0 count ok, 0 diff ok > sof: 2048 <= sof <= 0, freq 0.000 kHz > bytes 54683536 : duration 33302 > FPS: 29.99 > URB: 1478135/4000 uS/qty: 369.533 avg 390.357 std 22.968 min 3337.865 max (uS) > header: 79761/4000 uS/qty: 19.940 avg 18.495 std 1.875 min 336.719 max (uS) > latency: 281077/4000 uS/qty: 70.269 avg 83.102 std 5.104 min 735.000 max (uS) > decode: 1197057/4000 uS/qty: 299.264 avg 318.080 std 1.615 min 2806.667 max (uS) > raw decode speed: 365.470 Mbits/s > raw URB handling speed: 295.986 Mbits/s > throughput: 13.136 Mbits/s > URB decode CPU usage 3.594500 % > > Signed-off-by: Ricardo Ribalda > Reviewed-by: Tomasz Figa > Signed-off-by: Christoph Hellwig > --- > drivers/media/usb/uvc/uvc_video.c | 79 ++++++++++++++++++++++--------- > drivers/media/usb/uvc/uvcvideo.h | 4 +- > 2 files changed, 60 insertions(+), 23 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index f2f565281e63ff..d008c68fb6c806 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -6,11 +6,13 @@ > * Laurent Pinchart (laurent.pinchart@ideasonboard.com) > */ > Should we include ? > +#include > #include > #include > #include > #include > #include > +#include > #include > #include > #include > @@ -1096,6 +1098,26 @@ static int uvc_video_decode_start(struct uvc_streaming *stream, > return data[0]; > } > > +static inline struct device *stream_to_dmadev(struct uvc_streaming *stream) > +{ > + return bus_to_hcd(stream->dev->udev->bus)->self.sysdev; > +} > + > +static void uvc_urb_dma_sync(struct uvc_urb *uvc_urb, bool for_device) > +{ > + struct device *dma_dev = stream_to_dmadev(uvc_urb->stream); > + > + if (for_device) { > + dma_sync_sgtable_for_device(dma_dev, uvc_urb->sgt, > + DMA_FROM_DEVICE); The uvcvideo driver also supports video output devices (they are fairly rare, but they exist). We thus need to handle DMA_TO_DEVICE too. > + } else { > + dma_sync_sgtable_for_cpu(dma_dev, uvc_urb->sgt, > + DMA_FROM_DEVICE); > + invalidate_kernel_vmap_range(uvc_urb->buffer, > + uvc_urb->stream->urb_size); > + } > +} > + > /* > * uvc_video_decode_data_work: Asynchronous memcpy processing > * > @@ -1117,6 +1139,8 @@ static void uvc_video_copy_data_work(struct work_struct *work) > uvc_queue_buffer_release(op->buf); > } > > + uvc_urb_dma_sync(uvc_urb, true); > + > ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL); > if (ret < 0) > dev_err(&uvc_urb->stream->intf->dev, > @@ -1541,10 +1565,12 @@ static void uvc_video_complete(struct urb *urb) > * Process the URB headers, and optionally queue expensive memcpy tasks > * to be deferred to a work queue. > */ > + uvc_urb_dma_sync(uvc_urb, false); > stream->decode(uvc_urb, buf, buf_meta); > > /* If no async work is needed, resubmit the URB immediately. */ > if (!uvc_urb->async_operations) { > + uvc_urb_dma_sync(uvc_urb, true); > ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC); > if (ret < 0) > dev_err(&stream->intf->dev, > @@ -1560,24 +1586,46 @@ static void uvc_video_complete(struct urb *urb) > */ > static void uvc_free_urb_buffers(struct uvc_streaming *stream) > { > + struct device *dma_dev = stream_to_dmadev(stream); > struct uvc_urb *uvc_urb; > > for_each_uvc_urb(uvc_urb, stream) { > if (!uvc_urb->buffer) > continue; > > -#ifndef CONFIG_DMA_NONCOHERENT > - usb_free_coherent(stream->dev->udev, stream->urb_size, > - uvc_urb->buffer, uvc_urb->dma); > -#else > - kfree(uvc_urb->buffer); > -#endif > + dma_vunmap_noncontiguous(dma_dev, uvc_urb->buffer); > + dma_free_noncontiguous(dma_dev, stream->urb_size, uvc_urb->sgt, > + DMA_FROM_DEVICE); > + > uvc_urb->buffer = NULL; Maybe also uvc_urb->sgt = NULL; ? It's not strictly mandatory, but may make use-after-free bugs easier to spot. > } > > stream->urb_size = 0; > } > > +static bool uvc_alloc_urb_buffer(struct uvc_streaming *stream, > + struct uvc_urb *uvc_urb, gfp_t gfp_flags) > +{ > + struct device *dma_dev = stream_to_dmadev(stream); > + > + Extra blank line. > + uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size, > + DMA_FROM_DEVICE, gfp_flags, 0); > + if (!uvc_urb->sgt) > + return false; > + uvc_urb->dma = uvc_urb->sgt->sgl->dma_address; > + > + uvc_urb->buffer = dma_vmap_noncontiguous(dma_dev, stream->urb_size, > + uvc_urb->sgt); > + if (!uvc_urb->buffer) { > + dma_free_noncontiguous(dma_dev, stream->urb_size, > + uvc_urb->sgt, DMA_FROM_DEVICE); Same here, uvc_urb->sgt = NULL; > + return false; > + } > + > + return true; > +} > + > /* > * Allocate transfer buffers. This function can be called with buffers > * already allocated when resuming from suspend, in which case it will > @@ -1608,19 +1656,11 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, > > /* Retry allocations until one succeed. */ > for (; npackets > 1; npackets /= 2) { > + stream->urb_size = psize * npackets; A blank line here would be nice. > for (i = 0; i < UVC_URBS; ++i) { > struct uvc_urb *uvc_urb = &stream->uvc_urb[i]; > > - stream->urb_size = psize * npackets; > -#ifndef CONFIG_DMA_NONCOHERENT > - uvc_urb->buffer = usb_alloc_coherent( > - stream->dev->udev, stream->urb_size, > - gfp_flags | __GFP_NOWARN, &uvc_urb->dma); > -#else > - uvc_urb->buffer = > - kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN); > -#endif > - if (!uvc_urb->buffer) { > + if (!uvc_alloc_urb_buffer(stream, uvc_urb, gfp_flags)) { > uvc_free_urb_buffers(stream); > break; > } > @@ -1730,12 +1770,8 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream, > urb->context = uvc_urb; > urb->pipe = usb_rcvisocpipe(stream->dev->udev, > ep->desc.bEndpointAddress); > -#ifndef CONFIG_DMA_NONCOHERENT > urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; > urb->transfer_dma = uvc_urb->dma; > -#else > - urb->transfer_flags = URB_ISO_ASAP; > -#endif > urb->interval = ep->desc.bInterval; > urb->transfer_buffer = uvc_urb->buffer; > urb->complete = uvc_video_complete; > @@ -1795,10 +1831,8 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream, > > usb_fill_bulk_urb(urb, stream->dev->udev, pipe, uvc_urb->buffer, > size, uvc_video_complete, uvc_urb); > -#ifndef CONFIG_DMA_NONCOHERENT > urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; > urb->transfer_dma = uvc_urb->dma; > -#endif > > uvc_urb->urb = urb; > } > @@ -1895,6 +1929,7 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > > /* Submit the URBs. */ > for_each_uvc_urb(uvc_urb, stream) { > + uvc_urb_dma_sync(uvc_urb, true); > ret = usb_submit_urb(uvc_urb->urb, gfp_flags); > if (ret < 0) { > dev_err(&stream->intf->dev, > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h > index 97df5ecd66c9a7..fec24f1eca1c96 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -545,7 +545,8 @@ struct uvc_copy_op { > * @urb: the URB described by this context structure > * @stream: UVC streaming context > * @buffer: memory storage for the URB > - * @dma: DMA coherent addressing for the urb_buffer > + * @dma: Allocated DMA handle > + * @sgt: sgt_table with the urb locations in memory > * @async_operations: counter to indicate the number of copy operations > * @copy_operations: work descriptors for asynchronous copy operations > * @work: work queue entry for asynchronous decode > @@ -556,6 +557,7 @@ struct uvc_urb { > > char *buffer; > dma_addr_t dma; > + struct sg_table *sgt; A forward declaration of struct sg_table with the other forward declarations would be useful. > > unsigned int async_operations; > struct uvc_copy_op copy_operations[UVC_MAX_PACKETS]; -- Regards, Laurent Pinchart