Re: [PATCH 1/3] PCI: dwc: ep: Add dw_pcie_ep_deinit_notify()

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, May 28, 2024 at 03:00:37PM +0200, Niklas Cassel wrote:
> Add a DWC specific wrapper function (dw_pcie_ep_deinit_notify()) around
> pci_epc_deinit_notify(), similar to how we have a wrapper function
> (dw_pcie_ep_init_notify()) around pci_epc_init_notify().
> 
> This will allow the DWC glue drivers to use the same API layer for init
> and deinit notification.
> 
> Signed-off-by: Niklas Cassel <cassel@kernel.org>
> ---
>  drivers/pci/controller/dwc/pcie-designware-ep.c | 13 +++++++++++++
>  drivers/pci/controller/dwc/pcie-designware.h    |  5 +++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 2063cf2049e5..3c9079651dff 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -39,6 +39,19 @@ void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
>  }
>  EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
>  
> +/**
> + * dw_pcie_ep_deinit_notify - Notify EPF drivers about EPC deinitialization
> + *			      complete
> + * @ep: DWC EP device
> + */
> +void dw_pcie_ep_deinit_notify(struct dw_pcie_ep *ep)
> +{
> +	struct pci_epc *epc = ep->epc;
> +
> +	pci_epc_deinit_notify(epc);
> +}
> +EXPORT_SYMBOL_GPL(dw_pcie_ep_deinit_notify);

What is the value of this wrapper?  

I see that dw_pcie_ep_deinit_notify() would be parallel to
dw_pcie_ep_init_notify() and dw_pcie_ep_linkup(), but none of these
has any DWC-specific content other than the fact that
pcie-designware.h provides stubs for the non-CONFIG_PCIE_DW_EP case.

What if we added stubs to pci-epc.h pci_epc_init_notify(),
pci_epc_deinit_notify(), pci_epc_linkup(), and pci_epc_linkdown() for
the non-CONFIG_PCI_ENDPOINT case instead?  Then we might be able to
drop all these DWC-specific wrappers.

>  /**
>   * dw_pcie_ep_get_func_from_ep - Get the struct dw_pcie_ep_func corresponding to
>   *				 the endpoint function
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index f8e5431a207b..dc63f764b8ba 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -672,6 +672,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep);
>  int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep);
>  void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep);
>  void dw_pcie_ep_deinit(struct dw_pcie_ep *ep);
> +void dw_pcie_ep_deinit_notify(struct dw_pcie_ep *ep);
>  void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep);
>  int dw_pcie_ep_raise_intx_irq(struct dw_pcie_ep *ep, u8 func_no);
>  int dw_pcie_ep_raise_msi_irq(struct dw_pcie_ep *ep, u8 func_no,
> @@ -706,6 +707,10 @@ static inline void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
>  {
>  }
>  
> +static inline void dw_pcie_ep_deinit_notify(struct dw_pcie_ep *ep)
> +{
> +}
> +
>  static inline void dw_pcie_ep_cleanup(struct dw_pcie_ep *ep)
>  {
>  }
> -- 
> 2.45.1
>