Crate pci

PCI Configuration Space Access

Terminology

This crate deals with multiple types of interrupts:

• Legacy (INTx) interrupts are the oldest PCI interrupt representation.

  • Four interrupt pins are shared among all devices.
  • This crate refers to these legacy interrupts as “intx”.

• MSI (Message Signaled Interrupts) appeared with PCI express.

  • They allow devices to allocate up to 32 interrupt numbers.
  • This crate refers to these interrupts as “msi”.

• MSI-X messages appeared with PCIe 3.0.

  • They allow devices to allocate up to 2048 interrupt numbers.
  • This crate refers to these interrupts as “msix”.

Note: while pci currently uses port-io on x86 and mmio on aarch64, x86 may also support memory-based PCI configuration in the future; port-io is the legacy way to access the config space.

For context on the various interrupt mechanisms (MSI/MSI-X/INTx):

• this StackExchange reply
• PCI Express Base Specification, Revision 2, Chapter 6.1 - Interrupt & PME Support

Structs

• ModernInterruptSupport
  Returned by PciDevice::modern_interrupt_support
• MsixVectorEntry
  A single Message Signaled Interrupt entry.
• MsixVectorTable
  A memory-mapped array of MsixVectorEntry
• PciBus
  A PCI bus, which contains a list of PCI devices on that bus.
• PciDevice
  Contains information common to every type of PCI Device, and offers functions for reading/writing to the PCI configuration space.
• PciLocation
  The bus, slot, and function number of a given PCI device. This offers methods for reading and writing the PCI config space.

Enums

• InterruptPin
• PciCapability
• PciConfigSpaceAccessMechanism
  Lists the 2 possible PCI configuration space access mechanisms that can be found from the LSB of the devices’s BAR0

Functions

• get_pci_buses
  Returns a list of all PCI buses in this system. If the PCI bus hasn’t been initialized, this initializes the PCI bus & scans it to enumerates devices.
• get_pci_device_bsf
  Returns a reference to the PciDevice with the given bus, slot, func identifier. If the PCI bus hasn’t been initialized, this initializes the PCI bus & scans it to enumerates devices.
• pci_device_iter
  Returns an iterator that iterates over all PciDevices, in no particular guaranteed order. If the PCI bus hasn’t been initialized, this initializes the PCI bus & scans it to enumerates devices.