OPAL_PCI_SET_PHB_CAPI_MODE

#define OPAL_PCI_SET_PHB_CAPI_MODE           93

/* CAPI modes for PHB */
enum {
  OPAL_PHB_CAPI_MODE_PCIE            = 0,
  OPAL_PHB_CAPI_MODE_CAPI            = 1,
  OPAL_PHB_CAPI_MODE_SNOOP_OFF    = 2,
  OPAL_PHB_CAPI_MODE_SNOOP_ON        = 3,
  OPAL_PHB_CAPI_MODE_DMA             = 4,
  OPAL_PHB_CAPI_MODE_DMA_TVT1        = 5,
};

int64_t opal_pci_set_phb_capi_mode(uint64_t phb_id, uint64_t mode, uint64_t pe_number);

Switch the CAPP attached to the given PHB in one of the supported CAPI modes.

Parameters

uint64_t phb_id

the ID of the PHB which identifies attached CAPP to perform mode switch on

uint64_t mode

A mode id as described below

pe_number

PE number for the initiating device

Calling

Switch CAPP attached to the given PHB in one of the following supported modes:

OPAL_PHB_CAPI_MODE_PCIE               = 0
OPAL_PHB_CAPI_MODE_CAPI               = 1
OPAL_PHB_CAPI_MODE_SNOOP_OFF    = 2
OPAL_PHB_CAPI_MODE_SNOOP_ON   = 3
OPAL_PHB_CAPI_MODE_DMA                = 4
OPAL_PHB_CAPI_MODE_DMA_TVT1   = 5

Modes OPAL_PHB_CAPI_MODE_PCIE and OPAL_PHB_CAPI_MODE_CAPI are used to enable/disable CAPP attached to the PHB.

Modes OPAL_PHB_CAPI_MODE_SNOOP_OFF and OPAL_PHB_CAPI_MODE_SNOOP_ON are used to enable/disable CAPP snooping of Powerbus traffic for cache line invalidates.

Mode OPAL_PHB_CAPI_MODE_DMA and OPAL_PHB_CAPI_MODE_DMA_TVT1 are used to enable CAPP DMA mode.

Presently Mode OPAL_PHB_CAPI_MODE_DMA_TVT1 is exclusively used by the Mellanox CX5 adapter. Requesting this mode will also indicate to opal that the card requests maximum number of DMA read engines allocated to improve DMA read performance at cost of reduced bandwidth available to other traffic including CAPP-PSL transactions.

Notes

  • If PHB is in PEC2 then requesting mode OPAL_PHB_CAPI_MODE_DMA_TVT1 will allocate extra 16/8 dma read engines to the PHB depending on its stack (stack 0/ stack 1). This is needed to improve the Direct-GPU DMA read performance for the Mellanox CX5 card.

  • Mode OPAL_PHB_CAPI_MODE_PCIE not yet supported on Power-9.

  • Requesting mode OPAL_PHB_CAPI_MODE_CAPI on Power-9 will disable fast-reboot.

  • Modes OPAL_PHB_CAPI_MODE_DMA, OPAL_PHB_CAPI_MODE_SNOOP_OFF are not supported on Power-9 yet.

Return Codes

OPAL_SUCCESS

Switch to the requested capi mode performed successfully.

OPAL_PARAMETER

The requested value of mode or phb_id parameter is not valid.

OPAL_HARDWARE

An error occurred while switching the CAPP to requested mode.

OPAL_UNSUPPORTED

Switching to requested capi mode is not possible at the moment

OPAL_RESOURCE

CAPP ucode not available hence activating CAPP not supported.

OPAL_BUSY

CAPP is presently in recovery-mode and mode switch cannot be performed.