diff options
Diffstat (limited to 'docs/specs/acpi_cpu_hotplug.txt')
| -rw-r--r-- | docs/specs/acpi_cpu_hotplug.txt | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt index 9bb22d1270..9bd59ae0da 100644 --- a/docs/specs/acpi_cpu_hotplug.txt +++ b/docs/specs/acpi_cpu_hotplug.txt @@ -56,8 +56,11 @@ read access: no device check event to OSPM was issued. It's valid only when bit 0 is set. 2: Device remove event, used to distinguish device for which - no device eject request to OSPM was issued. - 3-7: reserved and should be ignored by OSPM + no device eject request to OSPM was issued. Firmware must + ignore this bit. + 3: reserved and should be ignored by OSPM + 4: if set to 1, OSPM requests firmware to perform device eject. + 5-7: reserved and should be ignored by OSPM [0x5-0x7] reserved [0x8] Command data: (DWORD access) contains 0 unless value last stored in 'Command field' is one of: @@ -79,10 +82,16 @@ write access: selected CPU device 2: if set to 1 clears device remove event, set by OSPM after it has emitted device eject request for the - selected CPU device + selected CPU device. 3: if set to 1 initiates device eject, set by OSPM when it - triggers CPU device removal and calls _EJ0 method - 4-7: reserved, OSPM must clear them before writing to register + triggers CPU device removal and calls _EJ0 method or by firmware + when bit #4 is set. In case bit #4 were set, it's cleared as + part of device eject. + 4: if set to 1, OSPM hands over device eject to firmware. + Firmware shall issue device eject request as described above + (bit #3) and OSPM should not touch device eject bit (#3) in case + it's asked firmware to perform CPU device eject. + 5-7: reserved, OSPM must clear them before writing to register [0x5] Command field: (1 byte access) value: 0: selects a CPU device with inserting/removing events and |