Differential D39228

Add a PCI driver that follows the Arm DEN0115 spec
ClosedPublic
Actions

Authored by andrew on Mar 23 2023, 9:57 AM.

Details

Reviewers

None

Group Reviewers

arm64

Commits

rGc9a05c072270: Add a PCI driver that follows the Arm DEN0115 spec

Summary

Add a n attachment to the pci_host_generic driver for the Arm DEN0115
PCI Configuration Space Access Firmware Interface [1]. This can be used
when PCI controllers need to implement quirks in the PCI root bus.
To handle this the firmware implements a SMCCC interface the driver can
use to read and write the configuration register.

This has been tested on a Raspberry Pi 4 booting with EDK2.

[1] https://developer.arm.com/documentation/den0115/latest

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

andrew created this revision.Mar 23 2023, 9:57 AM

Herald added subscribers: emaste, imp. · View Herald TranscriptMar 23 2023, 9:57 AM

andrew requested review of this revision.Mar 23 2023, 9:57 AM

Harbormaster completed remote builds in B50541: Diff 119320.Mar 23 2023, 9:57 AM

andrew added a parent revision: D39227: Allow pci_host_generic attachments to manage registers.Mar 23 2023, 9:58 AM

This revision was not accepted when it landed; it landed in state Needs Review.Apr 24 2023, 11:35 AM

Closed by commit rGc9a05c072270: Add a PCI driver that follows the Arm DEN0115 spec (authored by andrew). · Explain Why

This revision was automatically updated to reflect the committed changes.

andrew added a commit: rGc9a05c072270: Add a PCI driver that follows the Arm DEN0115 spec.

markmi_dsl-only.net added a subscriber: markmi_dsl-only.net.May 31 2023, 1:59 AM

markmi_dsl-only.net added inline comments.

sys/dev/pci/pci_host_generic_den0115.c
87	The comment's reference to >= v1.1 ("at least") vs. the code's check for v1.0 seem mismatched: . . . \|\| (SMCCC_VERSION_MAJOR(smccc_version) == 1 && SMCCC_VERSION_MINOR(smccc_version) == 0)

As a matter of curiosity, did something specific prompt having this form of PCI Configuration Space Access added? FreeBSD has been able to boot the RPi4B's for a long time, even via EDK2. So the test case does not seem to be a driving use case. Are there other known examples of this form of PCI Configuration Space Access needing-to-be/being-able-to-be used?