| Message ID | 20230228202132.4919-1-sven@svenpeter.dev |
|---|---|
| Headers | show |
| Series | Apple M1 USB4/Thunderbolt DART support | expand |
On 28/02/2023 8:21 pm, Sven Peter wrote: > The USB4 PCIe DARTs claim to support bypass but we never want to allow > that on externally facing ports. IOMMU drivers shouldn't be implementing their own individual policies for this - externally-facing ports should be correctly marked as such[1], so that the PCI layer is properly informed, which in turn will be picked up and handled properly by IOMMU core code. Thanks, Robin. [1] see Documentation/devicetree/bindings/pci/pci.txt > Acked-by: Hector Martin <marcan@marcan.st> > Signed-off-by: Sven Peter <sven@svenpeter.dev> > --- > drivers/iommu/apple-dart.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c > index 42666617803d..7d8b2b90cdb6 100644 > --- a/drivers/iommu/apple-dart.c > +++ b/drivers/iommu/apple-dart.c > @@ -182,6 +182,8 @@ struct apple_dart_hw { > u64 ttbr_addr_field_shift; > u64 ttbr_shift; > int ttbr_count; > + > + bool disable_bypass; > }; > > /* > @@ -1075,6 +1077,9 @@ static int apple_dart_probe(struct platform_device *pdev) > dart->pgsize = 1 << FIELD_GET(DART_PARAMS1_PAGE_SHIFT, dart_params[0]); > dart->supports_bypass = dart_params[1] & DART_PARAMS2_BYPASS_SUPPORT; > > + if (dart->hw->disable_bypass) > + dart->supports_bypass = 0; > + > switch (dart->hw->type) { > case DART_T8020: > case DART_T6000:
Hi, The M1 SoCs have a second slightly different variant of the regular DART used for the USB4 PCIe ports. It supports 64 instead of 16 streams which requires a minor change to the MMIO layout. There seems to be no way to tell them apart from the regular DARTs by just looking at the DART_PARAMs register so we have to add a new compatible for those. Change since v1: - apple,t8103-usb4-dart instead of apple,t8103-dart-usb4 as the compatible - collected Hector's tags Best, Sven Sven Peter (4): dt-bindings: iommu: dart: Add t8103-usb4-dart compatible iommu: dart: Add flag to override bypass support iommu: dart: Write to all DART_T8020_STREAM_SELECT iommu: dart: Add support for t8103 USB4 DART .../devicetree/bindings/iommu/apple,dart.yaml | 1 + drivers/iommu/apple-dart.c | 42 ++++++++++++++++++- 2 files changed, 41 insertions(+), 2 deletions(-)