Re: [PATCH v21 01/16] PCI: dwc: endpoint: Add multiple PFs support for dbi2

[Manivannan Sadhasivam <mani@kernel.org>]

On Fri, Sep 22, 2023 at 03:53:16PM +0900, Yoshihiro Shimoda wrote:
> The commit 24ede430fa49 ("PCI: designware-ep: Add multiple PFs support
> for DWC") added .func_conf_select() to get the configuration space of
> different PFs and assumed that the offsets between dbi and dbi2 would
> be the same.
> 
> However, Renesas R-Car Gen4 PCIe controllers have different offsets of
> function 1: dbi (+0x1000) and dbi2 (+0x800). To get the offset for dbi2,
> add .get_dbi2_offset() and dw_pcie_ep_get_dbi2_offset().
> 
> Note:
>  - .func_conf_select() should be renamed later.
>  - dw_pcie_ep_get_dbi2_offset() will call .func_conf_select()
>    if .get_dbi2_offset() doesn't exist for backward compatibility.
>  - dw_pcie_writeX_{dbi/dbi2} APIs accepted the func_no argument,
>    so that these offset calculations are contained in the API
>    definitions itself as it should.
> 
> [kwilczynski: commit log]
> Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-6-yoshihiro.shimoda.uh@renesas.com

No need of the "Link". It will be added by the maintainer while applying this
patch.

> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Your s-o-b tag should come last indicating that you are sending the patch.

- Mani

> Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
> ---
>  .../pci/controller/dwc/pcie-designware-ep.c   | 32 ++++++++++++++-----
>  drivers/pci/controller/dwc/pcie-designware.h  |  1 +
>  2 files changed, 25 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> index f9182f8d552f..851538ddec0a 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> @@ -52,21 +52,35 @@ static unsigned int dw_pcie_ep_func_select(struct dw_pcie_ep *ep, u8 func_no)
>  	return func_offset;
>  }
>  
> +static unsigned int dw_pcie_ep_get_dbi2_offset(struct dw_pcie_ep *ep, u8 func_no)
> +{
> +	unsigned int dbi2_offset = 0;
> +
> +	if (ep->ops->get_dbi2_offset)
> +		dbi2_offset = ep->ops->get_dbi2_offset(ep, func_no);
> +	else if (ep->ops->func_conf_select)     /* for backward compatibility */
> +		dbi2_offset = ep->ops->func_conf_select(ep, func_no);
> +
> +	return dbi2_offset;
> +}
> +
>  static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, u8 func_no,
>  				   enum pci_barno bar, int flags)
>  {
> -	u32 reg;
> -	unsigned int func_offset = 0;
> +	unsigned int func_offset, dbi2_offset;
>  	struct dw_pcie_ep *ep = &pci->ep;
> +	u32 reg, reg_dbi2;
>  
>  	func_offset = dw_pcie_ep_func_select(ep, func_no);
> +	dbi2_offset = dw_pcie_ep_get_dbi2_offset(ep, func_no);
>  
>  	reg = func_offset + PCI_BASE_ADDRESS_0 + (4 * bar);
> +	reg_dbi2 = dbi2_offset + PCI_BASE_ADDRESS_0 + (4 * bar);
>  	dw_pcie_dbi_ro_wr_en(pci);
> -	dw_pcie_writel_dbi2(pci, reg, 0x0);
> +	dw_pcie_writel_dbi2(pci, reg_dbi2, 0x0);
>  	dw_pcie_writel_dbi(pci, reg, 0x0);
>  	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
> -		dw_pcie_writel_dbi2(pci, reg + 4, 0x0);
> +		dw_pcie_writel_dbi2(pci, reg_dbi2 + 4, 0x0);
>  		dw_pcie_writel_dbi(pci, reg + 4, 0x0);
>  	}
>  	dw_pcie_dbi_ro_wr_dis(pci);
> @@ -228,16 +242,18 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
>  {
>  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
>  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +	unsigned int func_offset, dbi2_offset;
>  	enum pci_barno bar = epf_bar->barno;
>  	size_t size = epf_bar->size;
>  	int flags = epf_bar->flags;
> -	unsigned int func_offset = 0;
> +	u32 reg, reg_dbi2;
>  	int ret, type;
> -	u32 reg;
>  
>  	func_offset = dw_pcie_ep_func_select(ep, func_no);
> +	dbi2_offset = dw_pcie_ep_get_dbi2_offset(ep, func_no);
>  
>  	reg = PCI_BASE_ADDRESS_0 + (4 * bar) + func_offset;
> +	reg_dbi2 = PCI_BASE_ADDRESS_0 + (4 * bar) + dbi2_offset;
>  
>  	if (!(flags & PCI_BASE_ADDRESS_SPACE))
>  		type = PCIE_ATU_TYPE_MEM;
> @@ -253,11 +269,11 @@ static int dw_pcie_ep_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
>  
>  	dw_pcie_dbi_ro_wr_en(pci);
>  
> -	dw_pcie_writel_dbi2(pci, reg, lower_32_bits(size - 1));
> +	dw_pcie_writel_dbi2(pci, reg_dbi2, lower_32_bits(size - 1));
>  	dw_pcie_writel_dbi(pci, reg, flags);
>  
>  	if (flags & PCI_BASE_ADDRESS_MEM_TYPE_64) {
> -		dw_pcie_writel_dbi2(pci, reg + 4, upper_32_bits(size - 1));
> +		dw_pcie_writel_dbi2(pci, reg_dbi2 + 4, upper_32_bits(size - 1));
>  		dw_pcie_writel_dbi(pci, reg + 4, 0);
>  	}
>  
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index ef0b2efa9f93..6189884b4efa 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -341,6 +341,7 @@ struct dw_pcie_ep_ops {
>  	 * driver.
>  	 */
>  	unsigned int (*func_conf_select)(struct dw_pcie_ep *ep, u8 func_no);
> +	unsigned int (*get_dbi2_offset)(struct dw_pcie_ep *ep, u8 func_no);
>  };
>  
>  struct dw_pcie_ep_func {
> -- 
> 2.25.1
> 

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