From: Akhil R Date: Tue, 31 Mar 2026 10:23:01 +0000 (+0530) Subject: dmaengine: tegra: Use iommu-map for stream ID X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=321c0a15f027b83b20ed37717191a2187c9e2eb7;p=thirdparty%2Fkernel%2Flinux.git dmaengine: tegra: Use iommu-map for stream ID Use 'iommu-map', when provided, to get the stream ID to be programmed for each channel. Iterate over the channels registered and configure each channel device separately using of_dma_configure_id() to allow it to use a separate IOMMU domain for the transfer. However, do this in a second loop since the first loop populates the DMA device channels list and async_device_register() registers the channels. Both are prerequisites for using the channel device in the next loop. Channels will continue to use the same global stream ID if the 'iommu-map' property is not present in the device tree. Signed-off-by: Akhil R Reviewed-by: Frank Li Reviewed-by: Jon Hunter Link: https://patch.msgid.link/20260331102303.33181-9-akhilrajeev@nvidia.com Signed-off-by: Vinod Koul --- diff --git a/drivers/dma/tegra186-gpc-dma.c b/drivers/dma/tegra186-gpc-dma.c index 9bea2ffb3b9e5..939eb5462d0a8 100644 --- a/drivers/dma/tegra186-gpc-dma.c +++ b/drivers/dma/tegra186-gpc-dma.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -1380,9 +1381,13 @@ static int tegra_dma_program_sid(struct tegra_dma_channel *tdc, int stream_id) static int tegra_dma_probe(struct platform_device *pdev) { const struct tegra_dma_chip_data *cdata = NULL; + struct tegra_dma_channel *tdc; + struct tegra_dma *tdma; + struct dma_chan *chan; + struct device *chdev; + bool use_iommu_map = false; unsigned int i; u32 stream_id; - struct tegra_dma *tdma; int ret; cdata = of_device_get_match_data(&pdev->dev); @@ -1410,9 +1415,10 @@ static int tegra_dma_probe(struct platform_device *pdev) tdma->dma_dev.dev = &pdev->dev; - if (!tegra_dev_iommu_get_stream_id(&pdev->dev, &stream_id)) { - dev_err(&pdev->dev, "Missing iommu stream-id\n"); - return -EINVAL; + use_iommu_map = of_property_present(pdev->dev.of_node, "iommu-map"); + if (!use_iommu_map) { + if (!tegra_dev_iommu_get_stream_id(&pdev->dev, &stream_id)) + return dev_err_probe(&pdev->dev, -EINVAL, "Missing iommu stream-id\n"); } ret = device_property_read_u32(&pdev->dev, "dma-channel-mask", @@ -1424,9 +1430,10 @@ static int tegra_dma_probe(struct platform_device *pdev) tdma->chan_mask = TEGRA_GPCDMA_DEFAULT_CHANNEL_MASK; } + /* Initialize vchan for each channel and populate the channels list */ INIT_LIST_HEAD(&tdma->dma_dev.channels); for (i = 0; i < cdata->nr_channels; i++) { - struct tegra_dma_channel *tdc = &tdma->channels[i]; + tdc = &tdma->channels[i]; /* Check for channel mask */ if (!(tdma->chan_mask & BIT(i))) @@ -1446,10 +1453,6 @@ static int tegra_dma_probe(struct platform_device *pdev) vchan_init(&tdc->vc, &tdma->dma_dev); tdc->vc.desc_free = tegra_dma_desc_free; - - /* program stream-id for this channel */ - tegra_dma_program_sid(tdc, stream_id); - tdc->stream_id = stream_id; } dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(cdata->addr_bits)); @@ -1483,6 +1486,7 @@ static int tegra_dma_probe(struct platform_device *pdev) tdma->dma_dev.device_synchronize = tegra_dma_chan_synchronize; tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + /* Register the DMA device and the channels */ ret = dmaenginem_async_device_register(&tdma->dma_dev); if (ret < 0) { dev_err_probe(&pdev->dev, ret, @@ -1490,6 +1494,37 @@ static int tegra_dma_probe(struct platform_device *pdev) return ret; } + /* + * Configure stream ID for each channel from the channels registered + * above. This is done in a separate iteration to ensure that only + * the channels available and registered for the DMA device are used. + */ + list_for_each_entry(chan, &tdma->dma_dev.channels, device_node) { + chdev = &chan->dev->device; + tdc = to_tegra_dma_chan(chan); + + if (use_iommu_map) { + chdev->bus = pdev->dev.bus; + dma_coerce_mask_and_coherent(chdev, DMA_BIT_MASK(cdata->addr_bits)); + + ret = of_dma_configure_id(chdev, pdev->dev.of_node, + true, &tdc->id); + if (ret) + return dev_err_probe(chdev, ret, + "Failed to configure IOMMU for channel %d\n", tdc->id); + + if (!tegra_dev_iommu_get_stream_id(chdev, &stream_id)) + return dev_err_probe(chdev, -EINVAL, + "Failed to get stream ID for channel %d\n", tdc->id); + + chan->dev->chan_dma_dev = true; + } + + /* program stream-id for this channel */ + tegra_dma_program_sid(tdc, stream_id); + tdc->stream_id = stream_id; + } + ret = devm_of_dma_controller_register(&pdev->dev, pdev->dev.of_node, tegra_dma_of_xlate, tdma); if (ret < 0) {