[RESEND PATCH v9 1/5] powerpc: Document details on H_SCM_HEALTH hcall

[Ira Weiny]

On Tue, Jun 02, 2020 at 03:44:34PM +0530, Vaibhav Jain wrote:
> Add documentation to 'papr_hcalls.rst' describing the bitmap flags
> that are returned from H_SCM_HEALTH hcall as per the PAPR-SCM
> specification.
> 
> Cc: "Aneesh Kumar K . V" <aneesh.kumar at linux.ibm.com>
> Cc: Dan Williams <dan.j.williams at intel.com>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Ira Weiny <ira.weiny at intel.com>

Acked-by: Ira Weiny <ira.weiny at intel.com>

> Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>
> ---
> Changelog:
> 
> Resend:
> * None
> 
> v8..v9:
> * s/SCM/PMEM device. [ Dan Williams, Aneesh ]
> 
> v7..v8:
> * Added a clarification on bit-ordering of Health Bitmap
> 
> Resend:
> * None
> 
> v6..v7:
> * None
> 
> v5..v6:
> * New patch in the series
> ---
>  Documentation/powerpc/papr_hcalls.rst | 46 ++++++++++++++++++++++++---
>  1 file changed, 42 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/powerpc/papr_hcalls.rst b/Documentation/powerpc/papr_hcalls.rst
> index 3493631a60f8..48fcf1255a33 100644
> --- a/Documentation/powerpc/papr_hcalls.rst
> +++ b/Documentation/powerpc/papr_hcalls.rst
> @@ -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**
>  
> -- 
> 2.26.2
>