kernel/drivers/pci/controller/dwc/pcie-al.c, branch linux-6.18.y

PCI: dwc: Support ECAM mechanism by enabling iATU 'CFG Shift Feature'

2025-09-25T13:04:01Z

Designware databook r5.20a, sec 3.10.10.3 documents the 'CFG Shift Feature' of the internal Address Translation Unit (iATU). When this feature is enabled, it shifts/maps the BDF contained in the bits [27:12] of the target address in MEM TLP to become BDF of the CFG TLP. This essentially implements the Enhanced Configuration Address Mapping (ECAM) mechanism as defined in PCIe r6.0, sec 7.2.2. Currently, the driver is not making use of this CFG shift feature, thereby creating the iATU outbound map for each config access to the devices, causing latency and wasting CPU cycles. So to avoid this, configure the controller to enable CFG shift feature by enabling the 'CFG Shift' bit of the 'iATU Control 2 Register'. As a result of enabling CFG shift (ECAM), there is no longer a need to map the DBI register space separately as the DBI region falls under the 'config' space used for ECAM (as DBI is used to access the Root Port). For enabling ECAM using CFG shift, the platform has to satisfy following requirements: 1. Size of the 'config' memory space to be used as ECAM memory should be able to accommodate the number of buses defined in the 'bus-range' property of the host bridge DT node. 2. The 'config' memory space should be 256 MiB aligned. This requirement comes from PCIe r6.0, sec 7.2.2, which says the base address of ECAM memory should be aligned to a 2^(n+20) byte address boundary. For the DWC cores, n is 8, so this results in 2^28 byte alignment requirement. It should be noted that some DWC vendor glue drivers like pcie-al may use their own ECAM mechanism. For those controllers, set 'dw_pcie_rp::native_ecam' flag and skip enabling the CFG Shift feature in the DWC core. Signed-off-by: Krishna Chaitanya Chundru [mani: code split, reworded subject/description, comment, native_ecam flag] Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20250923-controller-dwc-ecam-v10-4-e84390ba75fa@kernel.org

PCI: al: Check IORESOURCE_BUS existence during probe

2024-05-28T16:14:24Z

If IORESOURCE_BUS is not provided in Device Tree it will be fabricated in of_pci_parse_bus_range(), so NULL pointer dereference should not happen here. But that's hard to verify, so check for NULL anyway. Found by Linux Verification Center (linuxtesting.org) with SVACE. Link: https://lore.kernel.org/linux-pci/20240503125705.46055-1-amishin@t-argos.ru Suggested-by: Bjorn Helgaas Signed-off-by: Aleksandr Mishin Signed-off-by: Krzysztof Wilczyński [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas

PCI: dwc: Drop host prefix from struct dw_pcie_host_ops members

2024-01-06T07:51:08Z

Since the name of the dw_pcie_host_ops struct makes it obvious that it's for the PCIe Host, drop the host prefix from the struct members. [kwilczynski: commit log] Suggested-by: Serge Semin Link: https://lore.kernel.org/linux-pci/20231220053829.1921187-2-yoshihiro.shimoda.uh@renesas.com Signed-off-by: Yoshihiro Shimoda Signed-off-by: Krzysztof Wilczyński Reviewed-by: Manivannan Sadhasivam Reviewed-by: Serge Semin Reviewed-by: Thomas Petazzoni Acked-by: Heiko Stuebner Acked-by: Jesper Nilsson Acked-by: Kunihiko Hayashi Acked-by: Lei Chuanhua Acked-by: Nobuhiro Iwamatsu

PCI: dwc: Rename struct pcie_port to dw_pcie_rp

2022-07-06T00:00:52Z

All of the DW PCIe core driver entities except the pcie_port struct have names with the "dw_" prefix to distinguish local and common PCIe name spaces, and endpoint-related entities have an "_ep" suffix. Rename struct pcie_port to dw_pcie_rp to make it more consistent with other names. [bhelgaas: commit log] Link: https://lore.kernel.org/r/20220624143428.8334-16-Sergey.Semin@baikalelectronics.ru Signed-off-by: Serge Semin Signed-off-by: Bjorn Helgaas Reviewed-by: Rob Herring Reviewed-by: Neil Armstrong Reviewed-by: Manivannan Sadhasivam Acked-by: Jesper Nilsson

PCI: al: Remove useless dw_pcie_ops

2021-02-24T17:09:50Z

We have removed the assumption that dw_pcie_ops always exists in the dwc core driver, so we can remove the useless dw_pcie_ops now. Link: https://lore.kernel.org/r/20210128144324.2fa8577c@xhacker.debian Signed-off-by: Jisheng Zhang Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Jonathan Chocron

Merge branch 'remotes/lorenzo/pci/dwc'

2020-12-15T21:11:11Z

- Support multiple ATU memory regions (Rob Herring) - Warn if non-prefetchable memory aperture is > 32-bit (Vidya Sagar) - Allow programming ATU for >4GB memory (Vidya Sagar) - Move ATU offset out of driver match data (Rob Herring) - Move "dbi", "dbi2", and "addr_space" resource setup to common code (Rob Herring) - Remove unneeded function wrappers (Rob Herring) - Ensure all outbound ATU windows are reset to reduce dependencies on bootloader (Rob Herring) - Use the default MSI irq_chip for dra7xx (Rob Herring) - Drop the .set_num_vectors() host op (Rob Herring) - Move MSI interrupt setup into DWC common code (Rob Herring) - Rework and simplify DWC MSI initialization (Rob Herring) - Move link handling to DWC common code (Rob Herring) - Move dw_pcie_msi_init() calls to DWC common code (Rob Herring) - Move dw_pcie_setup_rc() calls to DWC common code (Rob Herring) - Remove unnecessary wrappers around dw_pcie_host_init() (Rob Herring) - Revert "keystone: Drop duplicated 'num-viewport'" to prepare for detecting number of iATU regions without help from DT (Rob Herring) - Move inbound and outbound windows to common struct (Rob Herring) - Detect number of DWC iATU windows from device registers (Rob Herring) - Drop samsung,exynos5440-pcie binding (Marek Szyprowski) - Add samsung,exynos-pcie and samsung,exynos-pcie-phy bindings for Exynos5433 variant (Marek Szyprowski) - Rework phy-exynos-pcie driver to support Exynos5433 PCIe PHY (Jaehoon Chung) - Rework pci-exynos.c to support Exynos5433 PCIe host (Jaehoon Chung) - Move tegra "dbi" accesses to post common DWC initialization (Vidya Sagar) - Read tegra dbi" base address in application logic (Vidya Sagar) - Fix tegra ASPM-L1SS advertisement disable code (Vidya Sagar) - Set Tegra194 DesignWare IP version to 0x490A (Vidya Sagar) - Continue tegra unconfig sequence even if parts fail (Vidya Sagar) - Check return value of tegra_pcie_init_controller() (Vidya Sagar) - Disable tegra LTSSM during L2 entry (Vidya Sagar) - Add SM8250 SoC PCIe DT bindings and support (Manivannan Sadhasivam) - Add SM8250 BDF to SID mapping (Manivannan Sadhasivam) - Set 32-bit DMA mask for DWC MSI target address allocation (Vidya Sagar) * remotes/lorenzo/pci/dwc: PCI: dwc: Set 32-bit DMA mask for MSI target address allocation PCI: qcom: Add support for configuring BDF to SID mapping for SM8250 PCI: qcom: Add SM8250 SoC support dt-bindings: pci: qcom: Document PCIe bindings for SM8250 SoC PCI: tegra: Disable LTSSM during L2 entry PCI: tegra: Check return value of tegra_pcie_init_controller() PCI: tegra: Continue unconfig sequence even if parts fail PCI: tegra: Set DesignWare IP version PCI: tegra: Fix ASPM-L1SS advertisement disable code PCI: tegra: Read "dbi" base address to program in application logic PCI: tegra: Move "dbi" accesses to post common DWC initialization PCI: dwc: exynos: Rework the driver to support Exynos5433 variant phy: samsung: phy-exynos-pcie: rework driver to support Exynos5433 PCIe PHY dt-bindings: phy: exynos: add the samsung,exynos-pcie-phy binding dt-bindings: PCI: exynos: add the samsung,exynos-pcie binding dt-bindings: PCI: exynos: drop samsung,exynos5440-pcie binding PCI: dwc: Detect number of iATU windows PCI: dwc: Move inbound and outbound windows to common struct Revert "PCI: dwc/keystone: Drop duplicated 'num-viewport'" PCI: dwc: Remove unnecessary wrappers around dw_pcie_host_init() PCI: dwc: Move dw_pcie_setup_rc() to DWC common code PCI: dwc: Move dw_pcie_msi_init() into core PCI: dwc: Move link handling into common code PCI: dwc: Rework MSI initialization PCI: dwc: Move MSI interrupt setup into DWC common code PCI: dwc: Drop the .set_num_vectors() host op PCI: dwc/dra7xx: Use the common MSI irq_chip PCI: dwc: Ensure all outbound ATU windows are reset PCI: dwc/intel-gw: Remove some unneeded function wrappers PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code PCI: dwc/intel-gw: Move ATU offset out of driver match data PCI: dwc: Add support to program ATU for >4GB memory PCI: of: Warn if non-prefetchable memory aperture size is > 32-bit PCI: dwc: Support multiple ATU memory regions

PCI: Unify ECAM constants in native PCI Express drivers

2020-12-10T20:55:49Z

Add ECAM-related constants to provide a set of standard constants defining memory address shift values to the byte-level address that can be used to access the PCI Express Configuration Space, and then move native PCI Express controller drivers to use the newly introduced definitions retiring driver-specific ones. Refactor pci_ecam_map_bus() function to use newly added constants so that limits to the bus, device function and offset (now limited to 4K as per the specification) are in place to prevent the defective or malicious caller from supplying incorrect configuration offset and thus targeting the wrong device when accessing extended configuration space. This refactor also allows for the ".bus_shift" initialisers to be dropped when the user is not using a custom value as a default value will be used as per the PCI Express Specification. Thanks to Qian Cai , Michael Walle , and Vladimir Oltean for reporting a pci_ecam_create() issue with .bus_shift and to Vladimir for proposing the fix. [bhelgaas: incorporate Vladimir's fix, update commit log] Suggested-by: Bjorn Helgaas Link: https://lore.kernel.org/r/20201129230743.3006978-2-kw@linux.com Tested-by: Michael Walle Signed-off-by: Krzysztof Wilczyński Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Jon Derrick Reviewed-by: Bjorn Helgaas

PCI: dwc: Remove unnecessary wrappers around dw_pcie_host_init()

2020-11-19T10:51:41Z

Many calls to dw_pcie_host_init() are in a wrapper function with nothing else now. Let's remove the pointless extra layer. Link: https://lore.kernel.org/r/20201105211159.1814485-14-robh@kernel.org Tested-by: Marek Szyprowski Signed-off-by: Rob Herring Signed-off-by: Lorenzo Pieralisi Cc: Richard Zhu Cc: Lucas Stach Cc: Lorenzo Pieralisi Cc: Bjorn Helgaas Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Murali Karicheri Cc: Minghuan Lian Cc: Mingkai Hu Cc: Roy Zang Cc: Yue Wang Cc: Kevin Hilman Cc: Neil Armstrong Cc: Jerome Brunet Cc: Martin Blumenstingl Cc: Jonathan Chocron Cc: Jesper Nilsson Cc: Xiaowei Song Cc: Binghui Wang Cc: Kunihiko Hayashi Cc: Masahiro Yamada Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-amlogic@lists.infradead.org Cc: linux-arm-kernel@axis.com

PCI: dwc: Move "dbi", "dbi2", and "addr_space" resource setup into common code

2020-11-19T10:51:40Z

Most DWC drivers use the common register resource names "dbi", "dbi2", and "addr_space", so let's move their setup into the DWC common code. This means 'dbi_base' in particular is setup later, but it looks like no drivers touch DBI registers before dw_pcie_host_init or dw_pcie_ep_init. Link: https://lore.kernel.org/r/20201105211159.1814485-4-robh@kernel.org Tested-by: Marek Szyprowski Signed-off-by: Rob Herring Signed-off-by: Lorenzo Pieralisi Acked-by: Jingoo Han Cc: Kishon Vijay Abraham I Cc: Lorenzo Pieralisi Cc: Bjorn Helgaas Cc: Murali Karicheri Cc: Minghuan Lian Cc: Mingkai Hu Cc: Roy Zang Cc: Jonathan Chocron Cc: Jesper Nilsson Cc: Gustavo Pimentel Cc: Xiaowei Song Cc: Binghui Wang Cc: Andy Gross Cc: Bjorn Andersson Cc: Stanimir Varbanov Cc: Pratyush Anand Cc: Thierry Reding Cc: Jonathan Hunter Cc: Kunihiko Hayashi Cc: Masahiro Yamada Cc: linux-omap@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@axis.com Cc: linux-arm-msm@vger.kernel.org Cc: linux-tegra@vger.kernel.org

PCI: dwc: Remove storing of PCI resources

2020-09-08T15:37:02Z

The PCI bridge resources are stored in pci_host_bridge.windows, so there's no need to store them in a DWC specific struct. There's also no need to parse the resources and store them a 2nd time as they are mainly used for one time setup of iATU windows. Link: https://lore.kernel.org/r/20200821035420.380495-19-robh@kernel.org Signed-off-by: Rob Herring Signed-off-by: Lorenzo Pieralisi Cc: Murali Karicheri Cc: Lorenzo Pieralisi Cc: Bjorn Helgaas Cc: Jonathan Chocron Cc: Jingoo Han Cc: Gustavo Pimentel