Re: [PATCH v10 0/4] PCI: dwc: Add ECAM support with iATU configuration

From: Manivannan Sadhasivam
Date: Thu Sep 25 2025 - 09:06:56 EST



On Tue, 23 Sep 2025 16:56:50 +0530, Manivannan Sadhasivam wrote:
> The current implementation requires iATU for every configuration
> space access which increases latency & cpu utilization.
>
> Designware databook 5.20a, section 3.10.10.3 says about CFG Shift Feature,
> which shifts/maps the BDF (bits [31:16] of the third header DWORD, which
> would be matched against the Base and Limit addresses) of the incoming
> CfgRd0/CfgWr0 down to bits[27:12]of the translated address.
>
> [...]

Applied to pci/controller/qcom, thanks!

[1/4] PCI: dwc: Add support for ELBI resource mapping
commit: c96992a24beca0768c1c42ad25d6a466e17ec70f
[2/4] PCI: dwc: Prepare the driver for enabling ECAM mechanism using iATU 'CFG Shift Feature'
commit: f6fd357f7afbeb34a633e5688a23b9d7eb49d558
[3/4] PCI: qcom: Prepare for the DWC ECAM enablement
commit: 4660e50cf81800f82eeecf743ad1e3e97ab72190
[4/4] PCI: dwc: Support ECAM mechanism by enabling iATU 'CFG Shift Feature'
commit: 0da48c5b2fa731b21bc523c82d927399a1e508b0

Best regards,
--
Manivannan Sadhasivam <mani@xxxxxxxxxx>