PCI: endpoint: Expose endpoint DMA resources (part 2/3) [LWN.net]

From:		Koichiro Den <den-AT-valinux.co.jp>
To:		Jingoo Han <jingoohan1-AT-gmail.com>, Manivannan Sadhasivam <mani-AT-kernel.org>, Lorenzo Pieralisi <lpieralisi-AT-kernel.org>, Krzysztof Wilczyński <kwilczynski-AT-kernel.org>, Rob Herring <robh-AT-kernel.org>, Bjorn Helgaas <bhelgaas-AT-google.com>, Kishon Vijay Abraham I <kishon-AT-kernel.org>, Frank Li <Frank.Li-AT-kernel.org>
Subject:		[PATCH 0/3] PCI: endpoint: Expose endpoint DMA resources (part 2/3)
Date:		Thu, 21 May 2026 15:34:02 +0900
Message-ID:		<20260521063405.2842644-1-den@valinux.co.jp>
Cc:		Marek Vasut <marek.vasut+renesas-AT-mailbox.org>, Yoshihiro Shimoda <yoshihiro.shimoda.uh-AT-renesas.com>, linux-kernel-AT-vger.kernel.org, linux-pci-AT-vger.kernel.org
Archive-link:		Article

Hi,

This is part 2 of three series for PCI endpoint DMA.

The three series are:

  * part 1: dmaengine: dw-edma: Prepare for PCI EP DMA
  * part 2: PCI: endpoint: Expose endpoint DMA resources
  * part 3: PCI: endpoint: Add PCI DMA endpoint function

This series adds the PCI endpoint-side pieces used by the endpoint DMA
function. It defines the BAR metadata format, extends EPC auxiliary
resources with DMA-specific resource descriptions, and teaches the
DesignWare endpoint controller to publish its integrated DMA resources.

The metadata lives in a normal endpoint BAR, not in PCI config space. This
keeps discovery independent from controller-specific writable extended
capability storage.


Dependencies
============

This series is based on pci/endpoint at:

  f5aa97125491 ("misc: pci_endpoint_test: remove dead BAR read before doorbell trigger")

It also depends on part 1 for the dw-edma channel lookup helper used by
the DesignWare endpoint resource provider.

  [PATCH 00/12] dmaengine: dw-edma: Prepare for PCI EP DMA (part 1/3)
  https://lore.kernel.org/all/20260521063115.2842238-1-den@...


Best regards,
Koichiro


Koichiro Den (3):
  PCI: endpoint: Define endpoint DMA BAR metadata format
  PCI: endpoint: Add DMA auxiliary resource metadata
  PCI: dwc: Expose endpoint DMA resources

 MAINTAINERS                                   |   1 +
 .../pci/controller/dwc/pcie-designware-ep.c   |  77 ++++++++-
 include/linux/pci-ep-dma.h                    | 163 ++++++++++++++++++
 include/linux/pci-epc.h                       |  43 +++++
 4 files changed, 280 insertions(+), 4 deletions(-)
 create mode 100644 include/linux/pci-ep-dma.h

-- 
2.51.0