Re: [PATCH v13 1/3] PCI: make pci_dev_is_disconnected() helper public for other drivers

Bjorn Helgaas
2024-02-29T22:26:45Z

On Thu, Feb 22, 2024 at 04:02:49AM -0500, Ethan Zhao wrote:
> Make pci_dev_is_disconnected() public so that it can be called from
> Intel VT-d driver to quickly fix/workaround the surprise removal
> unplug hang issue for those ATS capable devices on PCIe switch downstream
> hotplug capable ports.
>
> Beside pci_device_is_present() function, this one has no config space
> space access, so is light enough to optimize the normal pure surprise
> removal and safe removal flow.
>
> Tested-by: Haorong Ye <yehaorong@bytedance.com>
> Signed-off-by: Ethan Zhao <haifeng.zhao@linux.intel.com>

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

> ---
> drivers/pci/pci.h | 5 -----
> include/linux/pci.h | 5 +++++
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index e9750b1b19ba..bfc56f7bee1c 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -368,11 +368,6 @@ static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
> return 0;
> }
>
> -static inline bool pci_dev_is_disconnected(const struct pci_dev *dev)
> -{
> - return dev->error_state == pci_channel_io_perm_failure;
> -}
> -
> /* pci_dev priv_flags */
> #define PCI_DEV_ADDED 0
> #define PCI_DPC_RECOVERED 1
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 7ab0d13672da..213109d3c601 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2517,6 +2517,11 @@ static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
> return NULL;
> }
>
> +static inline bool pci_dev_is_disconnected(const struct pci_dev *dev)
> +{
> + return dev->error_state == pci_channel_io_perm_failure;
> +}
> +
> void pci_request_acs(void);
> bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags);
> bool pci_acs_path_enabled(struct pci_dev *start,
> --
> 2.31.1
>