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

From: Ira Weiny
Date: Tue Jun 02 2020 - 17:21:26 EST


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@xxxxxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>

Acked-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxx>
> ---
> 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
>