[ndctl PATCH] libndctl/papr: Add support for reporting shutdown-count

[Vaibhav Jain <vaibhav@linux.ibm.com>]

Add support for reporting dirty-shutdown-count (DSC) for PAPR based
NVDIMMs. The sysfs attribute exposing this value is located at
nmemX/papr/dirty_shutdown.

This counter is also returned in payload for PAPR_PDSM_HEALTH as newly
introduced member 'dimm_dsc' in 'struct nd_papr_pdsm_health'. Presence
of 'DSC' is indicated by the PDSM_DIMM_DSC_VALID extension flag.

The patch implements 'ndctl_dimm_ops.smart_get_shutdown_count'
callback in implemented as papr_smart_get_shutdown_count().

Kernel side changes to support reporting DSC have been proposed at
[1]. With updated kernel 'ndctl list -DH' reports following output on
PPC64:

$ sudo ndctl list -DH
[
  {
    "dev":"nmem0",
    "health":{
      "health_state":"ok",
      "life_used_percentage":50,
      "shutdown_state":"clean",
      "shutdown_count":10
    }
  }
]

Link: https://lore.kernel.org/nvdimm/20210521111023.413732-1-vaibhav@linux.ibm.com
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
 ndctl/lib/libndctl.c  |  6 +++++-
 ndctl/lib/papr.c      | 23 +++++++++++++++++++++++
 ndctl/lib/papr_pdsm.h |  6 ++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c
index aa36a3c87c57..6ee426ae30e1 100644
--- a/ndctl/lib/libndctl.c
+++ b/ndctl/lib/libndctl.c
@@ -1795,8 +1795,12 @@ static int add_papr_dimm(struct ndctl_dimm *dimm, const char *dimm_base)
 
 		/* Allocate monitor mode fd */
 		dimm->health_eventfd = open(path, O_RDONLY|O_CLOEXEC);
-		rc = 0;
+		/* Get the dirty shutdown counter value */
+		sprintf(path, "%s/papr/dirty_shutdown", dimm_base);
+		if (sysfs_read_attr(ctx, path, buf) == 0)
+			dimm->dirty_shutdown = strtoll(buf, NULL, 0);
 
+		rc = 0;
 	} else if (strcmp(buf, "nvdimm_test") == 0) {
 		/* probe via common populate_dimm_attributes() */
 		rc = populate_dimm_attributes(dimm, dimm_base, "papr");
diff --git a/ndctl/lib/papr.c b/ndctl/lib/papr.c
index 9c6f2f045fc2..42ff200dc588 100644
--- a/ndctl/lib/papr.c
+++ b/ndctl/lib/papr.c
@@ -165,6 +165,9 @@ static unsigned int papr_smart_get_flags(struct ndctl_cmd *cmd)
 		if (health.extension_flags & PDSM_DIMM_HEALTH_RUN_GAUGE_VALID)
 			flags |= ND_SMART_USED_VALID;
 
+		if (health.extension_flags &  PDSM_DIMM_DSC_VALID)
+			flags |= ND_SMART_SHUTDOWN_COUNT_VALID;
+
 		return flags;
 	}
 
@@ -236,6 +239,25 @@ static unsigned int papr_smart_get_life_used(struct ndctl_cmd *cmd)
 		(100 - health.dimm_fuel_gauge) : 0;
 }
 
+static unsigned int papr_smart_get_shutdown_count(struct ndctl_cmd *cmd)
+{
+
+	struct nd_papr_pdsm_health health;
+
+	/* Ignore in case of error or invalid pdsm */
+	if (!cmd_is_valid(cmd) ||
+	    to_pdsm(cmd)->cmd_status != 0 ||
+	    to_pdsm_cmd(cmd) != PAPR_PDSM_HEALTH)
+		return 0;
+
+	/* get the payload from command */
+	health = to_payload(cmd)->health;
+
+	return (health.extension_flags & PDSM_DIMM_DSC_VALID) ?
+		(health.dimm_dsc) : 0;
+
+}
+
 struct ndctl_dimm_ops * const papr_dimm_ops = &(struct ndctl_dimm_ops) {
 	.cmd_is_supported = papr_cmd_is_supported,
 	.smart_get_flags = papr_smart_get_flags,
@@ -245,4 +267,5 @@ struct ndctl_dimm_ops * const papr_dimm_ops = &(struct ndctl_dimm_ops) {
 	.smart_get_health = papr_smart_get_health,
 	.smart_get_shutdown_state = papr_smart_get_shutdown_state,
 	.smart_get_life_used = papr_smart_get_life_used,
+	.smart_get_shutdown_count = papr_smart_get_shutdown_count,
 };
diff --git a/ndctl/lib/papr_pdsm.h b/ndctl/lib/papr_pdsm.h
index 1bac8a7fc933..f45b1e40c075 100644
--- a/ndctl/lib/papr_pdsm.h
+++ b/ndctl/lib/papr_pdsm.h
@@ -75,6 +75,9 @@
 /* Indicate that the 'dimm_fuel_gauge' field is valid */
 #define PDSM_DIMM_HEALTH_RUN_GAUGE_VALID 1
 
+/* Indicate that the 'dimm_dsc' field is valid */
+#define PDSM_DIMM_DSC_VALID 2
+
 /*
  * Struct exchanged between kernel & ndctl in for PAPR_PDSM_HEALTH
  * Various flags indicate the health status of the dimm.
@@ -103,6 +106,9 @@ struct nd_papr_pdsm_health {
 
 			/* Extension flag PDSM_DIMM_HEALTH_RUN_GAUGE_VALID */
 			__u16 dimm_fuel_gauge;
+
+			/* Extension flag PDSM_DIMM_DSC_VALID */
+			__u64 dimm_dsc;
 		};
 		__u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
 	};
-- 
2.31.1