Hi Christoph I guess you can merge this patch from your tree. I hope it is not too late in this release cycle.
Have a great week! On Sat, Mar 13, 2021 at 12:55 AM Ricardo Ribalda <riba...@chromium.org> wrote: > > On architectures where there is no coherent caching such as ARM use the > dma_alloc_noncontiguous API and handle manually the cache flushing using > dma_sync_sgtable(). > > If the architechture has coherent cache, the API falls back to > alloc_dma_pages, so we can remove the coherent caching code-path from the > driver, making it simpler. > > 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 % > > In non-affected architectures we see no significant impact. > > Eg: x86 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 70179056 : duration 33301 > FPS: 29.99 > URB: 288901/4897 uS/qty: 58.995 avg 26.022 std 4.319 min 253.853 max (uS) > header: 54792/4897 uS/qty: 11.189 avg 6.218 std 0.620 min 61.750 max (uS) > latency: 236602/4897 uS/qty: 48.315 avg 24.244 std 1.764 min 240.924 max (uS) > decode: 52298/4897 uS/qty: 10.679 avg 8.299 std 1.638 min 108.861 max (uS) > raw decode speed: 10.796 Gbits/s > raw URB handling speed: 1.949 Gbits/s > throughput: 16.859 Mbits/s > URB decode CPU usage 0.157000 % > > 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 71818320 : duration 33301 > FPS: 29.99 > URB: 321021/5000 uS/qty: 64.204 avg 23.001 std 10.430 min 268.837 max (uS) > header: 54308/5000 uS/qty: 10.861 avg 5.104 std 0.778 min 54.736 max (uS) > latency: 268799/5000 uS/qty: 53.759 avg 21.827 std 6.095 min 255.153 max (uS) > decode: 52222/5000 uS/qty: 10.444 avg 7.137 std 1.874 min 71.103 max (uS) > raw decode speed: 11.048 Gbits/s > raw URB handling speed: 1.789 Gbits/s > throughput: 17.253 Mbits/s > URB decode CPU usage 0.156800 % > > Signed-off-by: Ricardo Ribalda <riba...@chromium.org> > Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com> > Reviewed-by: Tomasz Figa <tf...@chromium.org> > Signed-off-by: Christoph Hellwig <h...@lst.de> > --- > > Changelog from v3 (Thanks Laurent!): > > - Rename stream_dir and stream_to_dmadev to avoid collisions > - Improve commit message > > drivers/media/usb/uvc/uvc_video.c | 94 +++++++++++++++++++++++-------- > drivers/media/usb/uvc/uvcvideo.h | 5 +- > 2 files changed, 73 insertions(+), 26 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c > b/drivers/media/usb/uvc/uvc_video.c > index f2f565281e63..cdd8eb500bb7 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -6,11 +6,14 @@ > * Laurent Pinchart (laurent.pinch...@ideasonboard.com) > */ > > +#include <linux/dma-mapping.h> > +#include <linux/highmem.h> > #include <linux/kernel.h> > #include <linux/list.h> > #include <linux/module.h> > #include <linux/slab.h> > #include <linux/usb.h> > +#include <linux/usb/hcd.h> > #include <linux/videodev2.h> > #include <linux/vmalloc.h> > #include <linux/wait.h> > @@ -1096,6 +1099,29 @@ static int uvc_video_decode_start(struct uvc_streaming > *stream, > return data[0]; > } > > +static inline enum dma_data_direction uvc_stream_dir( > + struct uvc_streaming *stream) > +{ > + if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) > + return DMA_FROM_DEVICE; > + else > + return DMA_TO_DEVICE; > +} > + > +static inline struct device *uvc_stream_to_dmadev(struct uvc_streaming > *stream) > +{ > + return bus_to_hcd(stream->dev->udev->bus)->self.sysdev; > +} > + > +static int uvc_submit_urb(struct uvc_urb *uvc_urb, gfp_t mem_flags) > +{ > + /* Sync DMA. */ > + dma_sync_sgtable_for_device(uvc_stream_to_dmadev(uvc_urb->stream), > + uvc_urb->sgt, > + uvc_stream_dir(uvc_urb->stream)); > + return usb_submit_urb(uvc_urb->urb, GFP_KERNEL); > +} > + > /* > * uvc_video_decode_data_work: Asynchronous memcpy processing > * > @@ -1117,7 +1143,7 @@ static void uvc_video_copy_data_work(struct work_struct > *work) > uvc_queue_buffer_release(op->buf); > } > > - ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL); > + ret = uvc_submit_urb(uvc_urb, GFP_KERNEL); > if (ret < 0) > dev_err(&uvc_urb->stream->intf->dev, > "Failed to resubmit video URB (%d).\n", ret); > @@ -1537,6 +1563,12 @@ static void uvc_video_complete(struct urb *urb) > /* Re-initialise the URB async work. */ > uvc_urb->async_operations = 0; > > + /* Sync DMA and invalidate vmap range. */ > + dma_sync_sgtable_for_cpu(uvc_stream_to_dmadev(uvc_urb->stream), > + uvc_urb->sgt, uvc_stream_dir(stream)); > + invalidate_kernel_vmap_range(uvc_urb->buffer, > + uvc_urb->stream->urb_size); > + > /* > * Process the URB headers, and optionally queue expensive memcpy > tasks > * to be deferred to a work queue. > @@ -1545,7 +1577,7 @@ static void uvc_video_complete(struct urb *urb) > > /* If no async work is needed, resubmit the URB immediately. */ > if (!uvc_urb->async_operations) { > - ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC); > + ret = uvc_submit_urb(uvc_urb, GFP_ATOMIC); > if (ret < 0) > dev_err(&stream->intf->dev, > "Failed to resubmit video URB (%d).\n", ret); > @@ -1560,24 +1592,49 @@ static void uvc_video_complete(struct urb *urb) > */ > static void uvc_free_urb_buffers(struct uvc_streaming *stream) > { > + struct device *dma_dev = uvc_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, > + uvc_stream_dir(stream)); > + > uvc_urb->buffer = NULL; > + uvc_urb->sgt = NULL; > } > > 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 = uvc_stream_to_dmadev(stream); > + > + uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size, > + uvc_stream_dir(stream), > + 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, > + uvc_stream_dir(stream)); > + 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 +1665,12 @@ 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; > + > 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 +1780,8 @@ 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 +1841,8 @@ 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; > } > @@ -1895,7 +1939,7 @@ static int uvc_video_start_transfer(struct > uvc_streaming *stream, > > /* Submit the URBs. */ > for_each_uvc_urb(uvc_urb, stream) { > - ret = usb_submit_urb(uvc_urb->urb, gfp_flags); > + ret = uvc_submit_urb(uvc_urb, gfp_flags); > if (ret < 0) { > dev_err(&stream->intf->dev, > "Failed to submit URB %u (%d).\n", > diff --git a/drivers/media/usb/uvc/uvcvideo.h > b/drivers/media/usb/uvc/uvcvideo.h > index 97df5ecd66c9..cce5e38133cd 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -219,6 +219,7 @@ > */ > > struct gpio_desc; > +struct sg_table; > struct uvc_device; > > /* TODO: Put the most frequently accessed fields at the beginning of > @@ -545,7 +546,8 @@ 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 +558,7 @@ struct uvc_urb { > > char *buffer; > dma_addr_t dma; > + struct sg_table *sgt; > > unsigned int async_operations; > struct uvc_copy_op copy_operations[UVC_MAX_PACKETS]; > -- > 2.31.0.rc2.261.g7f71774620-goog > -- Ricardo Ribalda _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu