Commit 901e3490 authored by Vaibhav Jain's avatar Vaibhav Jain Committed by Dan Williams
Browse files

powerpc: Document details on H_SCM_HEALTH hcall 



Add documentation to 'papr_hcalls.rst' describing the bitmap flags
that are returned from H_SCM_HEALTH hcall as per the PAPR-SCM
specification.

Signed-off-by: default avatarVaibhav Jain <vaibhav@linux.ibm.com>
Acked-by: default avatarIra Weiny <ira.weiny@intel.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20200615124407.32596-2-vaibhav@linux.ibm.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent b3a9e3b9

Documentation/powerpc/papr_hcalls.rst

+42 −4
Original line number Diff line number Diff line
@@ -220,13 +220,51 @@ from the LPAR memory. 
**H_SCM_HEALTH**



| Input: drcIndex

| Out: *health-bitmap, health-bit-valid-bitmap*

| Out: *health-bitmap (r4), health-bit-valid-bitmap (r5)*

| Return Value: *H_Success, H_Parameter, H_Hardware*



Given a DRC Index return the info on predictive failure and overall health of

the NVDIMM. The asserted bits in the health-bitmap indicate a single predictive

failure and health-bit-valid-bitmap indicate which bits in health-bitmap are

valid.

the PMEM device. The asserted bits in the health-bitmap indicate one or more states

(described in table below) of the PMEM device and health-bit-valid-bitmap indicate

which bits in health-bitmap are valid. The bits are reported in

reverse bit ordering for example a value of 0xC400000000000000

indicates bits 0, 1, and 5 are valid.



Health Bitmap Flags:



+------+-----------------------------------------------------------------------+

|  Bit |               Definition                                              |

+======+=======================================================================+

|  00  | PMEM device is unable to persist memory contents.                     |

|      | If the system is powered down, nothing will be saved.                 |

+------+-----------------------------------------------------------------------+

|  01  | PMEM device failed to persist memory contents. Either contents were   |

|      | not saved successfully on power down or were not restored properly on |

|      | power up.                                                             |

+------+-----------------------------------------------------------------------+

|  02  | PMEM device contents are persisted from previous IPL. The data from   |

|      | the last boot were successfully restored.                             |

+------+-----------------------------------------------------------------------+

|  03  | PMEM device contents are not persisted from previous IPL. There was no|

|      | data to restore from the last boot.                                   |

+------+-----------------------------------------------------------------------+

|  04  | PMEM device memory life remaining is critically low                   |

+------+-----------------------------------------------------------------------+

|  05  | PMEM device will be garded off next IPL due to failure                |

+------+-----------------------------------------------------------------------+

|  06  | PMEM device contents cannot persist due to current platform health    |

|      | status. A hardware failure may prevent data from being saved or       |

|      | restored.                                                             |

+------+-----------------------------------------------------------------------+

|  07  | PMEM device is unable to persist memory contents in certain conditions|

+------+-----------------------------------------------------------------------+

|  08  | PMEM device is encrypted                                              |

+------+-----------------------------------------------------------------------+

|  09  | PMEM device has successfully completed a requested erase or secure    |

|      | erase procedure.                                                      |

+------+-----------------------------------------------------------------------+

|10:63 | Reserved / Unused                                                     |

+------+-----------------------------------------------------------------------+



**H_SCM_PERFORMANCE_STATS**