From 73812307647a90234cbc1e474f2dec4bfa4ad34f Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 9 Sep 2026 11:40:11 +0200 Subject: [PATCH] dmaengine: sh: rcar-dmac: SMMU doesn't need IPMMU workaround R-Car Gen5 doesn't use an IPMMU anymore, but a SMMU. So, the workaround for the IPMMU becomes optional. Add a flag to distinguish. No functional change. Signed-off-by: Wolfram Sang Reviewed-by: Frank Li Reviewed-by: Geert Uytterhoeven Link: https://patch.msgid.link/20260909094009.2167-8-wsa+renesas@sang-engineering.com Signed-off-by: Vinod Koul --- drivers/dma/sh/rcar-dmac.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index cf07c17847d0..4eca52aeec02 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -219,10 +219,12 @@ struct rcar_dmac { * struct rcar_dmac_of_data - This driver's OF data * @chan_offset_base: DMAC channels base offset * @chan_offset_stride: DMAC channels offset stride + * @broken_ipmmu_microTLB0: flag if the connected IPMMU has microTLB0 issues */ struct rcar_dmac_of_data { u32 chan_offset_base; u32 chan_offset_stride; + unsigned int broken_ipmmu_microTLB0:1; }; /* ----------------------------------------------------------------------------- @@ -1877,8 +1879,9 @@ static int rcar_dmac_probe(struct platform_device *pdev) * can't use it with the IPMMU. As the IOMMU API operates at the device * level we can't disable it selectively, so ignore channel 0 for now if * the device is part of an IOMMU group. + * Not applicable if system uses something else than IPMMU like SMMU. */ - if (device_iommu_mapped(&pdev->dev)) + if (data->broken_ipmmu_microTLB0 && device_iommu_mapped(&pdev->dev)) dmac->channels_mask &= ~BIT(0); dmac->channels = devm_kcalloc(&pdev->dev, dmac->n_channels, @@ -2000,11 +2003,14 @@ static void rcar_dmac_shutdown(struct platform_device *pdev) static const struct rcar_dmac_of_data rcar_dmac_data = { .chan_offset_base = 0x8000, .chan_offset_stride = 0x80, + .broken_ipmmu_microTLB0 = 1, }; static const struct rcar_dmac_of_data rcar_gen4_dmac_data = { .chan_offset_base = 0x0, .chan_offset_stride = 0x1000, + /* Set to play safe. Needs testing if Gen4 is really affected */ + .broken_ipmmu_microTLB0 = 1, }; static const struct of_device_id rcar_dmac_of_ids[] = {