talos-op-linux/Documentation/ABI/testing/sysfs-bus-pci, branch master

PCI/ASPM: Add sysfs attributes for controlling ASPM link states

2019-11-21T23:30:24+00:00

Add sysfs attributes to Endpoints and other Upstream Ports to control ASPM, Clock PM, and L1 PM Substates. The new attributes are: /sys/devices/pci*/.../link/clkpm /sys/devices/pci*/.../link/l0s_aspm /sys/devices/pci*/.../link/l1_aspm /sys/devices/pci*/.../link/l1_1_aspm /sys/devices/pci*/.../link/l1_2_aspm /sys/devices/pci*/.../link/l1_1_pcipm /sys/devices/pci*/.../link/l1_2_pcipm An attribute is only visible if both ends of the Link leading to the device support the state. Writing y/1/on to the file enables the state; n/0/off disables it. These attributes can be used to tune the power/performance tradeoff for individual devices. [bhelgaas: commit log, rename directory to "link"] Link: https://lore.kernel.org/r/b1c83f8a-9bf6-eac5-82d0-cf5b90128fbf@gmail.com Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas

PCI/P2PDMA: Add sysfs group to display p2pmem stats

2018-10-17T17:18:15+00:00

Add a sysfs group to display statistics about P2P memory that is registered in each PCI device. Attributes in the group display the total amount of P2P memory, the amount available and whether it is published or not. Signed-off-by: Logan Gunthorpe Signed-off-by: Bjorn Helgaas Reviewed-by: Christoph Hellwig

Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2017-05-09T02:03:25+00:00

Pull PCI updates from Bjorn Helgaas: - add framework for supporting PCIe devices in Endpoint mode (Kishon Vijay Abraham I) - use non-postable PCI config space mappings when possible (Lorenzo Pieralisi) - clean up and unify mmap of PCI BARs (David Woodhouse) - export and unify Function Level Reset support (Christoph Hellwig) - avoid FLR for Intel 82579 NICs (Sasha Neftin) - add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig) - short-circuit config access failures for disconnected devices (Keith Busch) - remove D3 sleep delay when possible (Adrian Hunter) - freeze PME scan before suspending devices (Lukas Wunner) - stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava) - disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann) - add arch-specific alignment control to improve device passthrough by avoiding multiple BARs in a page (Yongji Xie) - add sysfs sriov_drivers_autoprobe to control VF driver binding (Bodong Wang) - allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas) - fix crashes when unbinding host controllers that don't support removal (Brian Norris) - add driver for MicroSemi Switchtec management interface (Logan Gunthorpe) - add driver for Faraday Technology FTPCI100 host bridge (Linus Walleij) - add i.MX7D support (Andrey Smirnov) - use generic MSI support for Aardvark (Thomas Petazzoni) - make Rockchip driver modular (Brian Norris) - advertise 128-byte Read Completion Boundary support for Rockchip (Shawn Lin) - advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin) - convert atomic_t to refcount_t in HV driver (Elena Reshetova) - add CPU IRQ affinity in HV driver (K. Y. Srinivasan) - fix PCI bus removal in HV driver (Long Li) - add support for ThunderX2 DMA alias topology (Jayachandran C) - add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki) - add ITE 8893 bridge DMA alias quirk (Jarod Wilson) - restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices (Manish Jaggi) * tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits) PCI: Don't allow unbinding host controllers that aren't prepared ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP MAINTAINERS: Add PCI Endpoint maintainer Documentation: PCI: Add userguide for PCI endpoint test function tools: PCI: Add sample test script to invoke pcitest tools: PCI: Add a userspace tool to test PCI endpoint Documentation: misc-devices: Add Documentation for pci-endpoint-test driver misc: Add host side PCI driver for PCI test function device PCI: Add device IDs for DRA74x and DRA72x dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access PCI: dwc: dra7xx: Workaround for errata id i870 dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode PCI: dwc: dra7xx: Add EP mode support PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently dt-bindings: PCI: Add DT bindings for PCI designware EP mode PCI: dwc: designware: Add EP mode support Documentation: PCI: Add binding documentation for pci-test endpoint function ixgbe: Use pcie_flr() instead of duplicating it IB/hfi1: Use pcie_flr() instead of duplicating it PCI: imx6: Fix spelling mistake: "contol" -> "control" ...

PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding

2017-04-20T13:53:51+00:00

Sometimes it is not desirable to bind SR-IOV VFs to drivers. This can save host side resource usage by VF instances that will be assigned to VMs. Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control that from the PF. To modify it, echo 0/n/N (disable probe) or 1/y/Y (enable probe) to: /sys/bus/pci/devices//sriov_drivers_autoprobe Note that this must be done before enabling VFs. The change will not take effect if VFs are already enabled. Simply, one can disable VFs by setting sriov_numvfs to 0, choose whether to probe or not, and then re-enable the VFs by restoring sriov_numvfs. [bhelgaas: changelog, ABI doc] Signed-off-by: Bodong Wang Signed-off-by: Eli Cohen Signed-off-by: Bjorn Helgaas Reviewed-by: Gavin Shan Reviewed-by: Alex Williamson

Documentation: ABI: testing: sysfs-bus-pci: Fix repetition of word 'the'

2017-03-09T07:33:27+00:00

The patch replaces 'the the' with 'the' in the documentation. Signed-off-by: sayli karnik Signed-off-by: Jonathan Corbet

PCI: Create revision file in sysfs

2016-11-21T22:25:32+00:00

Currently the revision isn't available via sysfs/libudev thus if one wants to know the value one needs to read through the config file, which can be quite time-consuming because it wakes/powers up the device. There are at least two userspace components which could make use the new file: libpciaccess and libdrm. The former wakes up _every_ PCI device, which can be observed via glxinfo when using Mesa 10.0+ drivers. The latter, in association with Mesa 13.0, can lead to 2-3 second delays while starting firefox, thunderbird or chromium. Link: https://bugs.freedesktop.org/show_bug.cgi?id=98502 Tested-by: Mauro Santos Signed-off-by: Emil Velikov Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Deucher Reviewed-by: Daniel Vetter

PCI: Allow numa_node override via sysfs

2014-11-06T22:10:06+00:00

NUMA systems with ACPI normally describe the physical topology via _PXM methods. But many BIOSes don't implement _PXM, which leaves the kernel with no way to discover the device topology, which reduces performance because we can't put memory and processes close to the device. The NUMA node of a PCI device is already exported in the sysfs "numa_node" file. Make that file writable so users can workaround the lack of _PXM methods in the BIOS. For example: echo 3 > /sys/devices/pci0000:ff/0000:03:1f.3/numa_node sets the node for PCI device 0000:03:1f.3. Writing the file emits a FW_BUG warning to encourage users to request firmware updates. It also taints the kernel with TAINT_FIRMWARE_WORKAROUND because overriding the node incorrectly can cause performance issues. [bhelgaas: changelog, documentation text] Signed-off-by: Prarit Bhargava Signed-off-by: Bjorn Helgaas CC: Myron Stowe CC: Alexander Ducyk CC: Jiang Liu

PCI/MSI: Add "msi_bus" sysfs MSI/MSI-X control for endpoints

2014-10-01T18:21:23+00:00

The "msi_bus" sysfs file for bridges sets a bus flag to allow or disallow future driver requests for MSI or MSI-X. Previously, the sysfs file existed for endpoints but did nothing. Add "msi_bus" support for endpoints, so an administrator can prevent the use of MSI and MSI-X for individual devices. Note that as for bridges, these changes only affect future driver requests for MSI or MSI-X, so drivers may need to be reloaded. Add documentation for the "msi_bus" sysfs file. [bhelgaas: changelog, comments, add "subordinate", add endpoint printk, rework bus_flags setting, make bus_flags printk unconditional] Signed-off-by: Yijing Wang Signed-off-by: Bjorn Helgaas

Merge branches 'pci/hotplug', 'pci/pci_is_bridge' and 'pci/virtualization' into next

2014-05-28T22:21:07+00:00

* pci/hotplug: PCI: cpqphp: Fix possible null pointer dereference NVMe: Implement PCIe reset notification callback PCI: Notify driver before and after device reset * pci/pci_is_bridge: pcmcia: Use pci_is_bridge() to simplify code PCI: pciehp: Use pci_is_bridge() to simplify code PCI: acpiphp: Use pci_is_bridge() to simplify code PCI: cpcihp: Use pci_is_bridge() to simplify code PCI: shpchp: Use pci_is_bridge() to simplify code PCI: rpaphp: Use pci_is_bridge() to simplify code sparc/PCI: Use pci_is_bridge() to simplify code powerpc/PCI: Use pci_is_bridge() to simplify code ia64/PCI: Use pci_is_bridge() to simplify code x86/PCI: Use pci_is_bridge() to simplify code PCI: Use pci_is_bridge() to simplify code PCI: Add new pci_is_bridge() interface PCI: Rename pci_is_bridge() to pci_has_subordinate() * pci/virtualization: PCI: Introduce new device binding path using pci_dev.driver_override Conflicts: drivers/pci/pci-sysfs.c

PCI: Introduce new device binding path using pci_dev.driver_override

2014-05-28T22:04:53+00:00

The driver_override field allows us to specify the driver for a device rather than relying on the driver to provide a positive match of the device. This shortcuts the existing process of looking up the vendor and device ID, adding them to the driver new_id, binding the device, then removing the ID, but it also provides a couple advantages. First, the above existing process allows the driver to bind to any device matching the new_id for the window where it's enabled. This is often not desired, such as the case of trying to bind a single device to a meta driver like pci-stub or vfio-pci. Using driver_override we can do this deterministically using: echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Previously we could not invoke drivers_probe after adding a device to new_id for a driver as we get non-deterministic behavior whether the driver we intend or the standard driver will claim the device. Now it becomes a deterministic process, only the driver matching driver_override will probe the device. To return the device to the standard driver, we simply clear the driver_override and reprobe the device: echo > /sys/bus/pci/devices/0000:03:00.0/driver_override echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind echo 0000:03:00.0 > /sys/bus/pci/drivers_probe Another advantage to this approach is that we can specify a driver override to force a specific binding or prevent any binding. For instance when an IOMMU group is exposed to userspace through VFIO we require that all devices within that group are owned by VFIO. However, devices can be hot-added into an IOMMU group, in which case we want to prevent the device from binding to any driver (override driver = "none") or perhaps have it automatically bind to vfio-pci. With driver_override it's a simple matter for this field to be set internally when the device is first discovered to prevent driver matches. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Alexander Graf Acked-by: Greg Kroah-Hartman