[PATCH v3 4/4] powerpc/papr_scm: Implement support for DSM_PAPR_SCM_HEALTH

Vaibhav Jain vaibhav at linux.ibm.com
Mon Mar 30 22:09:43 AEDT 2020


This patch implements support for papr_scm command
'DSM_PAPR_SCM_HEALTH' that returns a newly introduced 'struct
nd_papr_scm_dimm_health_stat' instance containing dimm health
information back to user space in response to ND_CMD_CALL. This
functionality is implemented in newly introduced papr_scm_get_health()
that queries the scm-dimm health information and then copies these bitmaps
to the package payload whose layout is defined by 'struct
papr_scm_ndctl_health'.

The patch also introduces a new member a new member 'struct
papr_scm_priv.health' thats an instance of 'struct
nd_papr_scm_dimm_health_stat' to cache the health information of a
scm-dimm. As a result functions drc_pmem_query_health() and
papr_flags_show() are updated to populate and use this new struct
instead of two be64 integers that we earlier used.

Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>

---
Changelog:

v2..v3: Updated struct nd_papr_scm_dimm_health_stat_v1 to use '__xx'
	types as its exported to the userspace [Aneesh]
	Changed the constants DSM_PAPR_SCM_DIMM_XX indicating dimm
	health from enum to #defines [Aneesh]

v1..v2: New patch in the series
---
 arch/powerpc/include/uapi/asm/papr_scm_dsm.h |  40 +++++++
 arch/powerpc/platforms/pseries/papr_scm.c    | 111 ++++++++++++++++---
 2 files changed, 134 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/uapi/asm/papr_scm_dsm.h b/arch/powerpc/include/uapi/asm/papr_scm_dsm.h
index c039a49b41b4..8265125304ca 100644
--- a/arch/powerpc/include/uapi/asm/papr_scm_dsm.h
+++ b/arch/powerpc/include/uapi/asm/papr_scm_dsm.h
@@ -132,6 +132,7 @@ struct nd_papr_scm_cmd_pkg {
  */
 enum dsm_papr_scm {
 	DSM_PAPR_SCM_MIN =  0x10000,
+	DSM_PAPR_SCM_HEALTH,
 	DSM_PAPR_SCM_MAX,
 };
 
@@ -158,4 +159,43 @@ static void *papr_scm_pcmd_to_payload(struct nd_papr_scm_cmd_pkg *pcmd)
 	else
 		return (void *)((__u8 *) pcmd + pcmd->payload_offset);
 }
+
+/* Various scm-dimm health indicators */
+#define DSM_PAPR_SCM_DIMM_HEALTHY       0
+#define DSM_PAPR_SCM_DIMM_UNHEALTHY     1
+#define DSM_PAPR_SCM_DIMM_CRITICAL      2
+#define DSM_PAPR_SCM_DIMM_FATAL         3
+
+/*
+ * Struct exchanged between kernel & ndctl in for PAPR_DSM_PAPR_SMART_HEALTH
+ * Various bitflags indicate the health status of the dimm.
+ *
+ * dimm_unarmed		: Dimm not armed. So contents wont persist.
+ * dimm_bad_shutdown	: Previous shutdown did not persist contents.
+ * dimm_bad_restore	: Contents from previous shutdown werent restored.
+ * dimm_scrubbed	: Contents of the dimm have been scrubbed.
+ * dimm_locked		: Contents of the dimm cant be modified until CEC reboot
+ * dimm_encrypted	: Contents of dimm are encrypted.
+ * dimm_health		: Dimm health indicator.
+ */
+struct nd_papr_scm_dimm_health_stat_v1 {
+	__u8 dimm_unarmed;
+	__u8 dimm_bad_shutdown;
+	__u8 dimm_bad_restore;
+	__u8 dimm_scrubbed;
+	__u8 dimm_locked;
+	__u8 dimm_encrypted;
+	__u16 dimm_health;
+};
+
+/*
+ * Typedef the current struct for dimm_health so that any application
+ * or kernel recompiled after introducing a new version automatically
+ * supports the new version.
+ */
+#define nd_papr_scm_dimm_health_stat nd_papr_scm_dimm_health_stat_v1
+
+/* Current version number for the dimm health struct */
+#define ND_PAPR_SCM_DIMM_HEALTH_VERSION 1
+
 #endif /* _UAPI_ASM_POWERPC_PAPR_SCM_DSM_H_ */
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
index 9a2614aaae88..16746d55f0b7 100644
--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c
@@ -47,8 +47,7 @@ struct papr_scm_priv {
 	struct mutex dimm_mutex;
 
 	/* Health information for the dimm */
-	__be64 health_bitmap;
-	__be64 health_bitmap_valid;
+	struct nd_papr_scm_dimm_health_stat health;
 };
 
 static int drc_pmem_bind(struct papr_scm_priv *p)
@@ -158,6 +157,7 @@ static int drc_pmem_query_health(struct papr_scm_priv *p)
 {
 	unsigned long ret[PLPAR_HCALL_BUFSIZE];
 	int64_t rc;
+	__be64 health;
 
 	rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
 	if (rc != H_SUCCESS) {
@@ -172,13 +172,41 @@ static int drc_pmem_query_health(struct papr_scm_priv *p)
 		return rc;
 
 	/* Store the retrieved health information in dimm platform data */
-	p->health_bitmap = ret[0];
-	p->health_bitmap_valid = ret[1];
+	health = ret[0] & ret[1];
 
 	dev_dbg(&p->pdev->dev,
 		"Queried dimm health info. Bitmap:0x%016llx Mask:0x%016llx\n",
-		be64_to_cpu(p->health_bitmap),
-		be64_to_cpu(p->health_bitmap_valid));
+		be64_to_cpu(ret[0]),
+		be64_to_cpu(ret[1]));
+
+	memset(&p->health, 0, sizeof(p->health));
+
+	/* Check for various masks in bitmap and set the buffer */
+	if (health & PAPR_SCM_DIMM_UNARMED_MASK)
+		p->health.dimm_unarmed = true;
+
+	if (health & PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK)
+		p->health.dimm_bad_shutdown = true;
+
+	if (health & PAPR_SCM_DIMM_BAD_RESTORE_MASK)
+		p->health.dimm_bad_restore = true;
+
+	if (health & PAPR_SCM_DIMM_ENCRYPTED)
+		p->health.dimm_encrypted = true;
+
+	if (health & PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED) {
+		p->health.dimm_locked = true;
+		p->health.dimm_scrubbed = true;
+	}
+
+	if (health & PAPR_SCM_DIMM_HEALTH_UNHEALTHY)
+		p->health.dimm_health = DSM_PAPR_SCM_DIMM_UNHEALTHY;
+
+	if (health & PAPR_SCM_DIMM_HEALTH_CRITICAL)
+		p->health.dimm_health = DSM_PAPR_SCM_DIMM_CRITICAL;
+
+	if (health & PAPR_SCM_DIMM_HEALTH_FATAL)
+		p->health.dimm_health = DSM_PAPR_SCM_DIMM_FATAL;
 
 	mutex_unlock(&p->dimm_mutex);
 	return 0;
@@ -340,6 +368,51 @@ static int cmd_to_func(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
 	return pkg->hdr.nd_command;
 }
 
+/* Fetch the DIMM health info and populate it in provided package. */
+static int papr_scm_get_health(struct papr_scm_priv *p,
+			       struct nd_papr_scm_cmd_pkg *pkg)
+{
+	int rc;
+	size_t copysize = sizeof(p->health);
+
+	rc = drc_pmem_query_health(p);
+	if (rc)
+		goto out;
+	/*
+	 * If the requested payload version is greater than one we know
+	 * about, return the payload version we know about and let
+	 * caller/userspace handle.
+	 */
+	if (pkg->payload_version > ND_PAPR_SCM_DIMM_HEALTH_VERSION)
+		pkg->payload_version = ND_PAPR_SCM_DIMM_HEALTH_VERSION;
+
+	if (pkg->hdr.nd_size_out < copysize) {
+		dev_dbg(&p->pdev->dev, "%s Payload not large enough\n",
+			__func__);
+		dev_dbg(&p->pdev->dev, "%s Expected %lu, available %u\n",
+			__func__, copysize, pkg->hdr.nd_size_out);
+		rc = -ENOSPC;
+		goto out;
+	}
+
+	dev_dbg(&p->pdev->dev, "%s Copying payload size=%lu version=0x%x\n",
+		__func__, copysize, pkg->payload_version);
+
+	/* Copy a subset of health struct based on copysize */
+	memcpy(papr_scm_pcmd_to_payload(pkg), &p->health, copysize);
+	pkg->hdr.nd_fw_size = copysize;
+
+out:
+	/*
+	 * Put the error in out package and return success from function
+	 * so that errors if any are propogated back to userspace.
+	 */
+	pkg->cmd_status = rc;
+	dev_dbg(&p->pdev->dev, "%s completion code = %d\n", __func__, rc);
+
+	return 0;
+}
+
 int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc)
 {
@@ -385,6 +458,11 @@ int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		*cmd_rc = 0;
 		break;
 
+	case DSM_PAPR_SCM_HEALTH:
+		call_pkg = nd_to_papr_cmd_pkg(buf);
+		*cmd_rc = papr_scm_get_health(p, call_pkg);
+		break;
+
 	default:
 		dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd_in);
 		*cmd_rc = -EINVAL;
@@ -419,7 +497,6 @@ static ssize_t papr_flags_show(struct device *dev,
 {
 	struct nvdimm *dimm = to_nvdimm(dev);
 	struct papr_scm_priv *p = nvdimm_provider_data(dimm);
-	__be64 health;
 	int rc;
 
 	rc = drc_pmem_query_health(p);
@@ -431,26 +508,26 @@ static ssize_t papr_flags_show(struct device *dev,
 	if (rc)
 		return rc;
 
-	health = p->health_bitmap & p->health_bitmap_valid;
-
-	/* Check for various masks in bitmap and set the buffer */
-	if (health & PAPR_SCM_DIMM_UNARMED_MASK)
+	if (p->health.dimm_unarmed)
 		rc += sprintf(buf, "not_armed ");
 
-	if (health & PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK)
+	if (p->health.dimm_bad_shutdown)
 		rc += sprintf(buf + rc, "save_fail ");
 
-	if (health & PAPR_SCM_DIMM_BAD_RESTORE_MASK)
+	if (p->health.dimm_bad_restore)
 		rc += sprintf(buf + rc, "restore_fail ");
 
-	if (health & PAPR_SCM_DIMM_ENCRYPTED)
+	if (p->health.dimm_encrypted)
 		rc += sprintf(buf + rc, "encrypted ");
 
-	if (health & PAPR_SCM_DIMM_SMART_EVENT_MASK)
+	if (p->health.dimm_health)
 		rc += sprintf(buf + rc, "smart_notify ");
 
-	if (health & PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED)
-		rc += sprintf(buf + rc, "scrubbed locked ");
+	if (p->health.dimm_scrubbed)
+		rc += sprintf(buf + rc, "scrubbed ");
+
+	if (p->health.dimm_locked)
+		rc += sprintf(buf + rc, "locked ");
 
 	if (rc > 0)
 		rc += sprintf(buf + rc, "\n");
-- 
2.24.1



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