summaryrefslogtreecommitdiff
path: root/drivers/acpi/hest.c
AgeCommit message (Collapse)Author
2009-11-04PCI: PCIe AER: honor ACPI HEST FIRMWARE FIRST modeMatt Domsch
Feedback from Hidetoshi Seto and Kenji Kaneshige incorporated. This correctly handles PCI-X bridges, PCIe root ports and endpoints, and prints debug messages when invalid/reserved types are found in the HEST. PCI devices not in domain/segment 0 are not represented in HEST, thus will be ignored. Today, the PCIe Advanced Error Reporting (AER) driver attaches itself to every PCIe root port for which BIOS reports it should, via ACPI _OSC. However, _OSC alone is insufficient for newer BIOSes. Part of ACPI 4.0 is the new APEI (ACPI Platform Error Interfaces) which is a way for OS and BIOS to handshake over which errors for which components each will handle. One table in ACPI 4.0 is the Hardware Error Source Table (HEST), where BIOS can define that errors for certain PCIe devices (or all devices), should be handled by BIOS ("Firmware First mode"), rather than be handled by the OS. Dell PowerEdge 11G server BIOS defines Firmware First mode in HEST, so that it may manage such errors, log them to the System Event Log, and possibly take other actions. The aer driver should honor this, and not attach itself to devices noted as such. Furthermore, Kenji Kaneshige reminded us to disallow changing the AER registers when respecting Firmware First mode. Platform firmware is expected to manage these, and if changes to them are allowed, it could break that firmware's behavior. The HEST parsing code may be replaced in the future by a more feature-rich implementation. This patch provides the minimum needed to prevent breakage until that implementation is available. Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>