Hi all, This series adds PCIe bandwidth controller (bwctrl) and associated PCIe cooling driver to the thermal core side for limiting PCIe Link Speed due to thermal reasons. PCIe bandwidth controller is a PCI express bus port service driver. A cooling device is created for each port the service driver finds if they support changing speeds. This series only adds support for controlling PCIe Link Speed. Controlling PCIe Link Width might also be useful but AFAIK, there is no mechanism for that until PCIe 6.0 (L0p). Based on feedback for v1, the thermal/cooling device side prefers Link Speed and Link Width to be separate cooling devices [1] which is taken into account in naming the cooling device for Link Speed but the Link Width one is not added yet as it would not be able to control anything at the moment. bwctrl is built on top of BW notifications revert. I'm just not sure what is the best practice when re-adding some old functionality in a modified form so please let me know if I need to somehow alter that patch. [1] https://lore.kernel.org/linux-pci/f35db90cd67adf4b0f48cd6f2a6ad8fbd0c1a679.camel@xxxxxxxxxxxxxxx/ v2: - Adds LNKCTL2 to RMW safe list in Documentation/PCI/pciebus-howto.rst - Renamed cooling devices from PCIe_Port_* to PCIe_Port_Link_Speed_* in order to plan for possibility of adding Link Width cooling devices later on - Moved struct thermal_cooling_device declaration to the correct patch - Small tweaks to Kconfig texts - Series rebased to resolve conflict (in the selftest list) Ilpo Järvinen (10): PCI: Protect Link Control 2 Register with RMW locking drm/radeon: Use RMW accessors for changing LNKCTL2 drm/amdgpu: Use RMW accessors for changing LNKCTL2 drm/IB/hfi1: Use RMW accessors for changing LNKCTL2 PCI: Store all PCIe Supported Link Speeds PCI: Cache PCIe device's Supported Speed Vector PCI/LINK: Re-add BW notification portdrv as PCIe BW controller PCI/bwctrl: Add "controller" part into PCIe bwctrl thermal: Add PCIe cooling driver selftests/pcie_bwctrl: Create selftests Documentation/PCI/pciebus-howto.rst | 8 +- MAINTAINERS | 8 + drivers/gpu/drm/amd/amdgpu/cik.c | 41 +-- drivers/gpu/drm/amd/amdgpu/si.c | 41 +-- drivers/gpu/drm/radeon/cik.c | 40 +-- drivers/gpu/drm/radeon/si.c | 40 +-- drivers/infiniband/hw/hfi1/pcie.c | 30 +- drivers/pci/pcie/Kconfig | 9 + drivers/pci/pcie/Makefile | 1 + drivers/pci/pcie/bwctrl.c | 309 ++++++++++++++++++ drivers/pci/pcie/portdrv.c | 9 +- drivers/pci/pcie/portdrv.h | 10 +- drivers/pci/probe.c | 38 ++- drivers/pci/remove.c | 2 + drivers/thermal/Kconfig | 10 + drivers/thermal/Makefile | 2 + drivers/thermal/pcie_cooling.c | 107 ++++++ include/linux/pci-bwctrl.h | 33 ++ include/linux/pci.h | 3 + include/uapi/linux/pci_regs.h | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/pcie_bwctrl/Makefile | 2 + .../pcie_bwctrl/set_pcie_cooling_state.sh | 122 +++++++ .../selftests/pcie_bwctrl/set_pcie_speed.sh | 67 ++++ 24 files changed, 799 insertions(+), 135 deletions(-) create mode 100644 drivers/pci/pcie/bwctrl.c create mode 100644 drivers/thermal/pcie_cooling.c create mode 100644 include/linux/pci-bwctrl.h create mode 100644 tools/testing/selftests/pcie_bwctrl/Makefile create mode 100755 tools/testing/selftests/pcie_bwctrl/set_pcie_cooling_state.sh create mode 100755 tools/testing/selftests/pcie_bwctrl/set_pcie_speed.sh -- 2.30.2
