Re: [ndctl PATCH v4 07/17] libcxl: add GET_HEALTH_INFO mailbox command and accessors

[Dan Williams <dan.j.williams@intel.com>]

)

On Thu, Oct 7, 2021 at 1:22 AM Vishal Verma <vishal.l.verma@intel.com> wrote:
>
> Add libcxl APIs to create a new GET_HEALTH_INFO mailbox command, the
> command output data structure (privately), and accessor APIs to return
> the different fields in the health info output.
>
> Cc: Ben Widawsky <ben.widawsky@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> ---
>  cxl/lib/private.h  |  47 ++++++++
>  cxl/lib/libcxl.c   | 286 +++++++++++++++++++++++++++++++++++++++++++++
>  cxl/libcxl.h       |  38 ++++++
>  util/bitmap.h      |  23 ++++
>  cxl/lib/libcxl.sym |  31 +++++
>  5 files changed, 425 insertions(+)
>
> diff --git a/cxl/lib/private.h b/cxl/lib/private.h
> index 3273f21..f76b518 100644
> --- a/cxl/lib/private.h
> +++ b/cxl/lib/private.h
> @@ -73,6 +73,53 @@ struct cxl_cmd_identify {
>         u8 qos_telemetry_caps;
>  } __attribute__((packed));
>
> +struct cxl_cmd_get_health_info {
> +       u8 health_status;
> +       u8 media_status;
> +       u8 ext_status;
> +       u8 life_used;
> +       le16 temperature;
> +       le32 dirty_shutdowns;
> +       le32 volatile_errors;
> +       le32 pmem_errors;
> +} __attribute__((packed));
> +
> +/* CXL 2.0 8.2.9.5.3 Byte 0 Health Status */
> +#define CXL_CMD_HEALTH_INFO_STATUS_MAINTENANCE_NEEDED_MASK             BIT(0)
> +#define CXL_CMD_HEALTH_INFO_STATUS_PERFORMANCE_DEGRADED_MASK           BIT(1)
> +#define CXL_CMD_HEALTH_INFO_STATUS_HW_REPLACEMENT_NEEDED_MASK          BIT(2)
> +
> +/* CXL 2.0 8.2.9.5.3 Byte 1 Media Status */
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_NORMAL                                0x0
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_NOT_READY                     0x1
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_PERSISTENCE_LOST              0x2
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_DATA_LOST                     0x3
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_POWERLOSS_PERSISTENCE_LOSS    0x4
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_SHUTDOWN_PERSISTENCE_LOSS     0x5
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_PERSISTENCE_LOSS_IMMINENT     0x6
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_POWERLOSS_DATA_LOSS           0x7
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_SHUTDOWN_DATA_LOSS            0x8
> +#define CXL_CMD_HEALTH_INFO_MEDIA_STATUS_DATA_LOSS_IMMINENT            0x9
> +
> +/* CXL 2.0 8.2.9.5.3 Byte 2 Additional Status */
> +#define CXL_CMD_HEALTH_INFO_EXT_LIFE_USED_MASK                         GENMASK(1, 0)
> +#define CXL_CMD_HEALTH_INFO_EXT_LIFE_USED_NORMAL                       0x0
> +#define CXL_CMD_HEALTH_INFO_EXT_LIFE_USED_WARNING                      0x1
> +#define CXL_CMD_HEALTH_INFO_EXT_LIFE_USED_CRITICAL                     0x2
> +#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_MASK                       GENMASK(3, 2)
> +#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_NORMAL                     (0x0 << 2)
> +#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_WARNING                    (0x1 << 2)
> +#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_CRITICAL                   (0x2 << 2)

So the kernel style for this would be to have:

#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_NORMAL                    (0)
#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_WARNING                  (1)
#define CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_CRITICAL                   (2)

...and then to check the value it would be:

FIELD_GET(CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_MASK, c->ext_status) ==
CXL_CMD_HEALTH_INFO_EXT_TEMPERATURE_NORMAL

...that way if we ever wanted to copy libcxl bits into the kernel it
will already be in the matching style to other CXL bitwise
definitions.

I think FIELD_GET() would also clarify a few of your helpers below,
but yeah a bit more infrastructure to import.

The rest of this looks ok to me.