Re: [PATCH 2/4] iommu: dart: Add flag to override bypass support

Hector Martin
2023-01-28T11:45:05Z

On 28/01/2023 20.11, Sven Peter wrote:
> The USB4 PCIe DARTs claim to support bypass but we never want to allow
> that on externally facing ports.
>
> 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:

Acked-by: Hector Martin <marcan@marcan.st>

- Hector