Re: [PATCH 1/3] PCI: dwc: Add support for vendor specific capability search

From: Jonathan Cameron
Date: Mon Jul 01 2024 - 06:56:10 EST


On Tue, 25 Jun 2024 15:08:11 +0530
Shradha Todi <shradha.t@xxxxxxxxxxx> wrote:

> Add vendor specific extended configuration space capability search API
> using struct dw_pcie pointer for DW controllers.
>
> Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-designware.c | 16 ++++++++++++++++
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 2 files changed, 17 insertions(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index 250cf7f40b85..b74e4a97558e 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -275,6 +275,22 @@ static u16 dw_pcie_find_next_ext_capability(struct dw_pcie *pci, u16 start,
> return 0;
> }
>
> +u16 dw_pcie_find_vsec_capability(struct dw_pcie *pci, u8 vsec_cap)
> +{
> + u16 vsec = 0;
> + u32 header;
> +
> + while ((vsec = dw_pcie_find_next_ext_capability(pci, vsec,
> + PCI_EXT_CAP_ID_VNDR))) {

Trivial but one more set of outer brackets than makes sense here.

> + header = dw_pcie_readl_dbi(pci, vsec + PCI_VNDR_HEADER);
> + if (PCI_VNDR_HEADER_ID(header) == vsec_cap)
> + return vsec;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(dw_pcie_find_vsec_capability);
> +
> u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap)
> {
> return dw_pcie_find_next_ext_capability(pci, 0, cap);
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index f8e5431a207b..77686957a30d 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -423,6 +423,7 @@ void dw_pcie_version_detect(struct dw_pcie *pci);
>
> u8 dw_pcie_find_capability(struct dw_pcie *pci, u8 cap);
> u16 dw_pcie_find_ext_capability(struct dw_pcie *pci, u8 cap);
> +u16 dw_pcie_find_vsec_capability(struct dw_pcie *pci, u8 vsec_cap);
>
> int dw_pcie_read(void __iomem *addr, int size, u32 *val);
> int dw_pcie_write(void __iomem *addr, int size, u32 val);