1. 06 May, 2010 1 commit
  2. 04 Nov, 2009 1 commit
    • Matt Domsch's avatar
      PCI: PCIe AER: honor ACPI HEST FIRMWARE FIRST mode · 05843961
      Matt Domsch authored
      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: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
      Reviewed-by: default avatarHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
      Signed-off-by: default avatarMatt Domsch <Matt_Domsch@dell.com>
      Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
      05843961