Re: [RFC] [PATCH net-next v5 1/3] PCI/ASPM: Introduce a new helper to report ASPM capability

[Bjorn Helgaas <helgaas@kernel.org>]

On Fri, Oct 08, 2021 at 12:15:50AM +0800, Kai-Heng Feng wrote:
> Introduce a new helper, pcie_aspm_capable(), to report ASPM capability.
> 
> The user will be introduced by next patch.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Change subject to:

  PCI/ASPM: Add pcie_aspm_capable()

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
> v6:
> v5:
>  - No change.
> 
> v4:
>  - Report aspm_capable instead.
> 
> v3:
>  - This is a new patch
> 
>  drivers/pci/pcie/aspm.c | 11 +++++++++++
>  include/linux/pci.h     |  2 ++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index 013a47f587cea..788e7496f33b1 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -1201,6 +1201,17 @@ bool pcie_aspm_enabled(struct pci_dev *pdev)
>  }
>  EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
>  
> +bool pcie_aspm_capable(struct pci_dev *pdev)
> +{
> +	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
> +
> +	if (!link)
> +		return false;
> +
> +	return link->aspm_capable;
> +}
> +EXPORT_SYMBOL_GPL(pcie_aspm_capable);
> +
>  static ssize_t aspm_attr_show_common(struct device *dev,
>  				     struct device_attribute *attr,
>  				     char *buf, u8 state)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index cd8aa6fce2041..a17baa39141f4 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1639,6 +1639,7 @@ int pci_disable_link_state_locked(struct pci_dev *pdev, int state);
>  void pcie_no_aspm(void);
>  bool pcie_aspm_support_enabled(void);
>  bool pcie_aspm_enabled(struct pci_dev *pdev);
> +bool pcie_aspm_capable(struct pci_dev *pdev);
>  #else
>  static inline int pci_disable_link_state(struct pci_dev *pdev, int state)
>  { return 0; }
> @@ -1647,6 +1648,7 @@ static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state)
>  static inline void pcie_no_aspm(void) { }
>  static inline bool pcie_aspm_support_enabled(void) { return false; }
>  static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; }
> +static inline bool pcie_aspm_capable(struct pci_dev *pdev) { return false; }
>  #endif
>  
>  #ifdef CONFIG_PCIEAER
> -- 
> 2.32.0
>