Subject: Re: [PATCH RESEND v5 13/18] PCI: dwc: Add start_link/stop_link inliners

From: Manivannan Sadhasivam <[email-masked]>
Date: Tue, 28 Jun 2022 12:13:13 +0530

On Fri, Jun 24, 2022 at 05:34:23PM +0300, Serge Semin wrote:
> There are several places in the generic DW PCIe code where the
> platform-specific PCIe link start/stop methods are called after making
> sure the ops handler and the callbacks are specified. Instead of repeating
> the same pattern over and over let's define the static-inline methods in
> the DW PCIe header file and use them in the relevant parts of the driver.
> 
> Note returning a negative error from the EP link start procedure if the
> start_link pointer isn't specified doesn't really make much sense since
> it's perfectly normal to have such a platform. Moreover even
> pci_epc_start() doesn't fail if no epc->ops->start callback is spotted. As
> a side-effect of this modification we can set the generic DW PCIe and
> Layerscape EP platform drivers free from the empty start_link callbacks
> and as such entirely dummy dw_pcie_ops instances.
> 
> Signed-off-by: Serge Semin <[email-masked]>

Reviewed-by: Manivannan Sadhasivam <[email-masked]>

Thanks,
Mani

> Reviewed-by: Rob Herring <[email-masked]>
> 
> ---
> 
> Changelog v4:
> - This is a new patch created on the v4 lap of the series.
> ---
>  drivers/pci/controller/dwc/pci-layerscape-ep.c    | 12 ------------
>  drivers/pci/controller/dwc/pcie-designware-ep.c   |  8 ++------
>  drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++++------
>  drivers/pci/controller/dwc/pcie-designware-plat.c | 10 ----------
>  drivers/pci/controller/dwc/pcie-designware.h      | 14 ++++++++++++++
>  5 files changed, 20 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> index 39f4664bd84c..ad99707b3b99 100644
> --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
> +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> @@ -32,15 +32,6 @@ struct ls_pcie_ep {
>  	const struct ls_pcie_ep_drvdata *drvdata;
>  };
>  
> -static int ls_pcie_establish_link(struct dw_pcie *pci)
> -{
> -	return 0;
> -}
> -
> -static const struct dw_pcie_ops dw_ls_pcie_ep_ops = {
> -	.start_link = ls_pcie_establish_link,
> -};
> -
>  static const struct pci_epc_features*
>  ls_pcie_ep_get_features(struct dw_pcie_ep *ep)
>  {
> @@ -106,19 +97,16 @@ static const struct dw_pcie_ep_ops ls_pcie_ep_ops = {
>  
>  static const struct ls_pcie_ep_drvdata ls1_ep_drvdata = {
>  	.ops = &ls_pcie_ep_ops,
> -	.dw_pcie_ops = &dw_ls_pcie_ep_ops,
>  };
>  
>  static const struct ls_pcie_ep_drvdata ls2_ep_drvdata = {
>  	.func_offset = 0x20000,
>  	.ops = &ls_pcie_ep_ops,
> -	.dw_pcie_ops = &dw_ls_pcie_ep_ops,
>  };
>  
>  static const struct ls_pcie_ep_drvdata lx2_ep_drvdata = {
>  	.func_offset = 0x8000,
>  	.ops = &ls_pcie_ep_ops,
> -	.dw_pcie_ops = &dw_ls_pcie_ep_ops,
>  };
>  
>  static const struct of_device_id ls_pcie_ep_of_match[] = {
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index 7ad349c32082..15b8059544e3 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -435,8 +435,7 @@ static void dw_pcie_ep_stop(struct pci_epc *epc)
>  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>  
> -	if (pci->ops && pci->ops->stop_link)
> -		pci->ops->stop_link(pci);
> +	dw_pcie_stop_link(pci);
>  }
>  
>  static int dw_pcie_ep_start(struct pci_epc *epc)
> @@ -444,10 +443,7 @@ static int dw_pcie_ep_start(struct pci_epc *epc)
>  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>  
> -	if (!pci->ops || !pci->ops->start_link)
> -		return -EINVAL;
> -
> -	return pci->ops->start_link(pci);
> +	return dw_pcie_start_link(pci);
>  }
>  
>  static const struct pci_epc_features*
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 2f13eec4812d..c49a3bde7a2a 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -409,8 +409,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  
>  	dw_pcie_setup_rc(pp);
>  
> -	if (!dw_pcie_link_up(pci) && pci->ops && pci->ops->start_link) {
> -		ret = pci->ops->start_link(pci);
> +	if (!dw_pcie_link_up(pci)) {
> +		ret = dw_pcie_start_link(pci);
>  		if (ret)
>  			goto err_free_msi;
>  	}
> @@ -427,8 +427,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
>  	return 0;
>  
>  err_stop_link:
> -	if (pci->ops && pci->ops->stop_link)
> -		pci->ops->stop_link(pci);
> +	dw_pcie_stop_link(pci);
>  
>  err_free_msi:
>  	if (pp->has_msi_ctrl)
> @@ -444,8 +443,7 @@ void dw_pcie_host_deinit(struct pcie_port *pp)
>  	pci_stop_root_bus(pp->bridge->bus);
>  	pci_remove_root_bus(pp->bridge->bus);
>  
> -	if (pci->ops && pci->ops->stop_link)
> -		pci->ops->stop_link(pci);
> +	dw_pcie_stop_link(pci);
>  
>  	if (pp->has_msi_ctrl)
>  		dw_pcie_free_msi(pp);
> diff --git a/drivers/pci/controller/dwc/pcie-designware-plat.c b/drivers/pci/controller/dwc/pcie-designware-plat.c
> index 0c5de87d3cc6..abf1afac6064 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-plat.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-plat.c
> @@ -36,15 +36,6 @@ static const struct of_device_id dw_plat_pcie_of_match[];
>  static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
>  };
>  
> -static int dw_plat_pcie_establish_link(struct dw_pcie *pci)
> -{
> -	return 0;
> -}
> -
> -static const struct dw_pcie_ops dw_pcie_ops = {
> -	.start_link = dw_plat_pcie_establish_link,
> -};
> -
>  static void dw_plat_pcie_ep_init(struct dw_pcie_ep *ep)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> @@ -140,7 +131,6 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	pci->dev = dev;
> -	pci->ops = &dw_pcie_ops;
>  
>  	dw_plat_pcie->pci = pci;
>  	dw_plat_pcie->mode = mode;
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 7d6e9b7576be..8ba239292634 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -365,6 +365,20 @@ static inline void dw_pcie_dbi_ro_wr_dis(struct dw_pcie *pci)
>  	dw_pcie_writel_dbi(pci, reg, val);
>  }
>  
> +static inline int dw_pcie_start_link(struct dw_pcie *pci)
> +{
> +	if (pci->ops && pci->ops->start_link)
> +		return pci->ops->start_link(pci);
> +
> +	return 0;
> +}
> +
> +static inline void dw_pcie_stop_link(struct dw_pcie *pci)
> +{
> +	if (pci->ops && pci->ops->stop_link)
> +		pci->ops->stop_link(pci);
> +}
> +
>  #ifdef CONFIG_PCIE_DW_HOST
>  irqreturn_t dw_handle_msi_irq(struct pcie_port *pp);
>  void dw_pcie_setup_rc(struct pcie_port *pp);
> -- 
> 2.35.1
> 

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