On Wed, Jul 17, 2024 at 03:55:06PM -0500, Wei Huang wrote:
> Add an API function to allow endpoint device drivers to check
> if the interrupt vector mode is allowed. If allowed, drivers
> can proceed with updating ST tags.
Wrap commit log to fill 75 columns
Wrap code/comments to fit in 80.
Here and below, capitalize technical terms defined in spec ("Interrupt
Vector Mode", "Steering Tag").
> Co-developed-by: Eric Van Tassell <Eric.VanTassell@xxxxxxx>
> Signed-off-by: Eric Van Tassell <Eric.VanTassell@xxxxxxx>
> Signed-off-by: Wei Huang <wei.huang2@xxxxxxx>
> Reviewed-by: Ajit Khaparde <ajit.khaparde@xxxxxxxxxxxx>
> Reviewed-by: Somnath Kotur <somnath.kotur@xxxxxxxxxxxx>
> Reviewed-by: Andy Gospodarek <andrew.gospodarek@xxxxxxxxxxxx>
> ---
> drivers/pci/pcie/tph.c | 29 +++++++++++++++++++++++++++++
> include/linux/pci-tph.h | 3 +++
> 2 files changed, 32 insertions(+)
>
> diff --git a/drivers/pci/pcie/tph.c b/drivers/pci/pcie/tph.c
> index fb8e2f920712..7183370b0977 100644
> --- a/drivers/pci/pcie/tph.c
> +++ b/drivers/pci/pcie/tph.c
> @@ -39,6 +39,17 @@ static void set_ctrl_reg_req_en(struct pci_dev *pdev, u8 req_type)
> pci_write_config_dword(pdev, pdev->tph_cap + PCI_TPH_CTRL, reg_val);
> }
>
> +static bool int_vec_mode_supported(struct pci_dev *pdev)
> +{
> + u32 reg_val;
> + u8 mode;
> +
> + pci_read_config_dword(pdev, pdev->tph_cap + PCI_TPH_CAP, ®_val);
> + mode = FIELD_GET(PCI_TPH_CAP_INT_VEC, reg_val);
> +
> + return !!mode;
> +}
> +
> void pcie_tph_set_nostmode(struct pci_dev *pdev)
> {
> if (!pdev->tph_cap)
> @@ -60,3 +71,21 @@ void pcie_tph_init(struct pci_dev *pdev)
> {
> pdev->tph_cap = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_TPH);
> }
> +
> +/**
> + * pcie_tph_intr_vec_supported() - Check if interrupt vector mode supported for dev
> + * @pdev: pci device
> + *
> + * Return:
> + * true : intr vector mode supported
> + * false: intr vector mode not supported
> + */
> +bool pcie_tph_intr_vec_supported(struct pci_dev *pdev)
> +{
> + if (!pdev->tph_cap || pci_tph_disabled() || !pdev->msix_enabled ||
> + !int_vec_mode_supported(pdev))
> + return false;
IMO the int_vec_mode_supported() helper is overkill and could be
inlined here. The other booleans can be checked first.
> +
> + return true;
> +}
> +EXPORT_SYMBOL(pcie_tph_intr_vec_supported);
> diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
> index 8fce3969277c..854677651d81 100644
> --- a/include/linux/pci-tph.h
> +++ b/include/linux/pci-tph.h
> @@ -12,9 +12,12 @@
> #ifdef CONFIG_PCIE_TPH
> void pcie_tph_disable(struct pci_dev *dev);
> void pcie_tph_set_nostmode(struct pci_dev *dev);
> +bool pcie_tph_intr_vec_supported(struct pci_dev *dev);
> #else
> static inline void pcie_tph_disable(struct pci_dev *dev) {}
> static inline void pcie_tph_set_nostmode(struct pci_dev *dev) {}
> +static inline bool pcie_tph_intr_vec_supported(struct pci_dev *dev)
> +{ return false; }
> #endif
>
> #endif /* LINUX_PCI_TPH_H */
> --
> 2.45.1
>
