Hey all, Here's some patches that add an Erratum to enable non-coherent DMA support for PolarFire SoC. By nature of being an FPGA, and due to the PCIe root ports being only 32-bit capable, many bitstreams configure the FPGA fabric such that peripherals in the fabric become non-coherent. The PCIe root ports on PolarFire SoC are connected to the core-complex via the fabric, and therefore can be (and regularly are) made DMA non-coherent. The Icicle Kit Reference Design has been configuring the PCIe root port in this manner since late 2022 and in a way unsupported by mainline since earlier that year. Adding this non-coherent DMA support makes PCIe functional on those FPGA designs. Daire did almost all the work to figure out how to support these kinds of designs, and this series depends on his patches to introduce the required dma-ranges handling for the root port driver: https://lore.kernel.org/linux-pci/20240531085333.2501399-1-daire.mcnamara@xxxxxxxxxxxxx/ The final patch depends on: https://lore.kernel.org/linux-pci/20240527-slather-backfire-db4605ae7cd7@wendy/ I'm not sure if an Erratum is really the right way to go about doing this, but I didn't want to make ARCH_MICROCHIP depend on NONPORTABLE. An alternative would be to add a menu under drivers/soc like Renesas does and allow it to be toggled as an option there instead. Thanks, Conor. CC: Paul Walmsley <paul.walmsley@xxxxxxxxxx> CC: Palmer Dabbelt <palmer@xxxxxxxxxxx> CC: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> CC: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx> CC: Rob Herring <robh@xxxxxxxxxx> CC: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx> CC: Samuel Holland <samuel.holland@xxxxxxxxxx> CC: linux-riscv@xxxxxxxxxxxxxxxxxxx CC: devicetree@xxxxxxxxxxxxxxx Conor Dooley (5): cache: ccache: allow building for PolarFire cache: ccache: add mpfs to nonstandard cache ops list RISC-V: Add an MPFS erratum for PCIe riscv: dts: microchip: modify memory map & add dma-ranges for pcie on icicle riscv: dts: microchip: update pcie reg properties arch/riscv/Kconfig.errata | 19 +++++ .../dts/microchip/mpfs-icicle-kit-fabric.dtsi | 77 ++++++++++++------- .../boot/dts/microchip/mpfs-icicle-kit.dts | 44 +++++++++-- .../dts/microchip/mpfs-m100pfs-fabric.dtsi | 6 +- .../dts/microchip/mpfs-polarberry-fabric.dtsi | 6 +- drivers/cache/Kconfig | 2 +- drivers/cache/sifive_ccache.c | 2 + 7 files changed, 116 insertions(+), 40 deletions(-) -- 2.43.2
