PCI bus support in Linux kernel

⚲ Most used API

🗝️ Acronyms:

• ACPI - Advanced Configuration and Power Interface
• ACS - Access Control Service
• AER - Advanced Error Reporting port service
• ASPM - Active State Power Management
• EDR - Error Disconnect Recover
• FLR - function level reset
• HT - Hypertransport
• BAR - Base Address Registers
• BW - Bandwidth
• DPC - Downstream Port Containment port service
• EP - Endpoint
• mmrbc - maximum memory read byte count
• mps - maximum payload size
• MWI - Memory-Write-Invalidate
• PM - Power Management
• PMC - ... ... Controller
• PME - ... ... Event, port service
• SR-IOV - Single-root input/output virtualization
• VF - virtual functions

⚲ User space API:

Querying information from a shell:

• man 8 lspci -vv
• column -t /proc/bus/pci/devices

• man 2 pciconfig_read, man 2 pciconfig_write, man 2 pciconfig_iobase - pci device information handling
• uapi/linux/pci.h _inc
• uapi/linux/pci_regs.h _inc

⚲ Kernel space API:

• linux/pci.h _inc
• pci_device_id _id - has vendor, device and class IDs. It is used for probing.
• pci_driver _id - the central struct
• module_pci_driver _id- helper macro to register pci_driver. It uses pci_register_driver _id and pci_unregister_driver _id.
• pci_dev _id - device descriptor
• pci_enable_device _id, pci_disable_device _id - must be called in probe and remove callbacks of pci_driver.
• pci_set_drvdata _id, pci_get_drvdata _id
• pci_name _id
• pci_set_master _id
• pcim_iomap_regions _id / pcim_iounmap_regions _id or pci_request_region _id, pci_request_regions _id/ pci_release_regions _id,
• pci_iomap _id, pci_iounmap _id
• pci_alloc_irq_vectors _id/ pci_free_irq_vectors _id, pci_request_irq _idor pci_irq_vector _id
• to_pci_dev _id
• pci_resource_flags _id, pci_resource_start _id, pci_resource_len _id
• pci_dev_put _id
• pci_read_config_dword _id, pci_write_config_dword _id
• pci_set_power_state _id

👁 Examples:

• PCI Linux Driver Template
• samples/v4l/v4l2-pci-skeleton.c _src
• pci _ltp

⚙️ Internals

linux/pci_ids.h _inc
drivers/pci _src
pci_ops _id

📚 Mainline documents

PCI driver API _doc

PCI Support Library _doc

PCI Hotplug Support Library _doc

PCI Peer-to-Peer DMA Support _doc

📚 PCI subsystem docs

PCI subsystem _doc, newer on the top:

Boot Interrupts reroute _doc

X86_REROUTE_FOR_BROKEN_BOOT_IRQS

Kernel parameters _docpci=ioapicreroute

EP - Endpoint Framework _doc

Querying information from shell:

find /sys/kernel/config/pci_ep/

EPC - EP Controller:

linux/pci-epc.h _inc pci_epc_create _id, devm_pci_epc_create _id

EPF - EP Function:

linux/pci-epf.h _inc pci_epf_create _id

Internals: drivers/pci/endpoint/ _src

Driver to test endpoint functionality: drivers/pci/endpoint/functions/pci-epf-test.c _src

PCIe virtualization, SR-IOV _doc, 2009

API: pci_enable_sriov _id, pci_disable_sriov _id, sriov_configure _id

MSI - Message Signaled Interrupts _doc, 2008

MSI Example:

vectors = pci_alloc_irq_vectors _id(pci_dev, 1, 1, PCI_IRQ_MSI | PCI_IRQ_MSIX);
irq = pci_irq_vector _id(pci_dev, 0);

AER - Advanced Error Reporting _doc, 2006

API: linux/aer.h _inc, pci_enable_pcie_error_reporting _id, pci_disable_pcie_error_reporting _id, pci_aer_clear_nonfatal_status _id

ERS - Error Recovery System _doc:

API: pci_error_handlers _id, pci_ers_result _id, pci_channel_state_t _id

PCIe - PCI Express Port Bus Driver _doc, 2004

API: pcie_port_service_driver _id,pcie_port_service_register _id, pcie_port_service_unregister _id

Old manual PCI API _doc

pci_get_device _id, pci_get_class _id, pci_get_subsys _id, pci_dev_put _id

💾 Historical:

• LDD3:PCI Drivers
• LDD3:PCI Drivers, pdf
• http://www.tldp.org/LDP/tlk/dd/pci.html

📚 References

• PCI Express
• Category:Peripheral Component Interconnect
• https://wiki.osdev.org/PCI
• https://lwn.net/Kernel/Index/#PCI