| .. _OPAL_PCI_PHB_MMIO_ENABLE: |
| |
| OPAL_PCI_PHB_MMIO_ENABLE |
| ======================== |
| |
| .. code-block:: c |
| |
| #define OPAL_PCI_PHB_MMIO_ENABLE 27 |
| |
| int64_t opal_pci_phb_mmio_enable(uint64_t phb_id, uint16_t window_type, |
| uint16_t window_num, uint16_t enable); |
| |
| .. note:: Appears to be POWER7 p7ioc specific. Likely to be removed soon. |
| |
| **WARNING:** following documentation is from old sources, and is possibly |
| not representative of OPALv3 as implemented by skiboot. This should be |
| used as a starting point for full documentation. |
| |
| |
| The host calls this function to enable or disable PHB decode of the PCI IO |
| and Memory address spaces below that PHB. Window_num selects an mmio window |
| within that address space. Enable set to '1' enables the PHB to decode and |
| forward system real addresses to PCI memory, while enable set to '0' disables |
| PHB decode and forwarding for the address range defined in a particular MMIO |
| window. |
| |
| Not all PHB hardware may support disabling some or all MMIO windows. OPAL |
| returns :ref:`OPAL_UNSUPPORTED` if called to disable an MMIO window for which |
| hardware does not support disable. KVM may call this function for all MMIO |
| windows and ignore the opal_unsuppsorted return code so long as KVM has |
| disabled MMIO to all downstream PCI devices and assured that KVM and OS guest |
| partitions cannot issue CI loads/stores to these address spaces from the |
| processor (e.g.,via HPT). |
| |
| OPAL returns :ref:`OPAL_SUCCESS` for calls to OPAL to enable them for PHBs that do |
| not support disable. |
| |
| ``phb_id`` |
| is the value from the PHB node ibm,opal-phbid property. |
| |
| ``window_type`` |
| specifies 32-bit or 64-bit PCI memory |
| |
| '0' selects PCI IO Space |
| |
| '1' selects 32-bit PCI memory space |
| |
| '2' selects 64 bit PCI memory space |
| |
| ``window_num`` |
| is the MMIO window number within the specified PCI memory space |
| |
| ``enable`` |
| specifies to enable or disable this MMIO window. |