Re: [PATCH RFC NOT TESTED] PCI: intel-gw: Use use_parent_dt_ranges and clean up intel_pcie_cpu_addr_fixup()

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Mar 05, 2025 at 12:07:54PM -0500, Frank Li wrote:
> Remove intel_pcie_cpu_addr_fixup() as the DT bus fabric should provide correct
> address translation. Set use_parent_dt_ranges to allow the DWC core driver to
> fetch address translation from the device tree.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Any update on this, Chuanhua?

I plan to merge v12 of Frank's series [1] for v6.15.  We need to know
ASAP if that would break intel-gw.

If we knew that it was safe to also apply this patch to remove
intel_pcie_cpu_addr(), that would be even better.

I will plan to apply the patch below on top of Frank's series [1] for
v6.15 unless I hear that it would break something.

Bjorn

[1] https://lore.kernel.org/r/20250315201548.858189-1-helgaas@kernel.org

> ---
> This patches basic on
> https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/
> 
> I have not hardware to test and there are not intel,lgm-pcie in kernel
> tree.
> 
> Your dts should correct reflect hardware behavor, ref:
> https://lore.kernel.org/linux-pci/Z8huvkENIBxyPKJv@axis.com/T/#mb7ae78c3a22324b37567d24ecc1c810c1b3f55c5
> 
> According to your intel_pcie_cpu_addr_fixup()
> 
> Basically, config space/io/mem space need minus SZ_256. parent bus range
> convert it to original value.
> 
> Look for driver owner, who help test this and start move forward to remove
> cpu_addr_fixup() work.
> ---
> Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/pci/controller/dwc/pcie-intel-gw.c | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-intel-gw.c b/drivers/pci/controller/dwc/pcie-intel-gw.c
> index 9b53b8f6f268e..c21906eced618 100644
> --- a/drivers/pci/controller/dwc/pcie-intel-gw.c
> +++ b/drivers/pci/controller/dwc/pcie-intel-gw.c
> @@ -57,7 +57,6 @@
>  	PCIE_APP_IRN_INTA | PCIE_APP_IRN_INTB | \
>  	PCIE_APP_IRN_INTC | PCIE_APP_IRN_INTD)
>  
> -#define BUS_IATU_OFFSET			SZ_256M
>  #define RESET_INTERVAL_MS		100
>  
>  struct intel_pcie {
> @@ -381,13 +380,7 @@ static int intel_pcie_rc_init(struct dw_pcie_rp *pp)
>  	return intel_pcie_host_setup(pcie);
>  }
>  
> -static u64 intel_pcie_cpu_addr(struct dw_pcie *pcie, u64 cpu_addr)
> -{
> -	return cpu_addr + BUS_IATU_OFFSET;
> -}
> -
>  static const struct dw_pcie_ops intel_pcie_ops = {
> -	.cpu_addr_fixup = intel_pcie_cpu_addr,
>  };
>  
>  static const struct dw_pcie_host_ops intel_pcie_dw_ops = {
> @@ -409,6 +402,7 @@ static int intel_pcie_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, pcie);
>  	pci = &pcie->pci;
>  	pci->dev = dev;
> +	pci->use_parent_dt_ranges = true;
>  	pp = &pci->pp;
>  
>  	ret = intel_pcie_get_resources(pdev);
> 
> ---
> base-commit: 1552be4855dacca5ea39b15b1ef0b96c91dbea0d
> change-id: 20250305-intel-7c25bfb498b1
> 
> Best regards,
>