Subject: Re: [PATCH V2 4/9] PCI/TPH: Implement a command line option to force No ST Mode

From: Bjorn Helgaas <[email-masked]>
Date: Fri, 7 Jun 2024 12:42:37 -0500

On Fri, May 31, 2024 at 04:38:36PM -0500, Wei Huang wrote:
> When "No ST mode" is enabled, end-point devices can generate TPH headers
> but with all steering tags treated as zero. A steering tag of zero is
> interpreted as "using the default policy" by the root complex. This is
> essential to quantify the benefit of steering tags for some given
> workloads.

>  #ifdef CONFIG_PCIE_TPH
>  int pcie_tph_disable(struct pci_dev *dev);
> +int tph_set_dev_nostmode(struct pci_dev *dev);

Exported functions need a "pci" or "pcie_" prefix.  We haven't been
completely consistent on this; we have "pci_acs_*", which is obviously
PCIe-specific, but we do also have pcie_find_root_port() etc.