Re: [PATCH v5 4/4] powerpc/papr_scm: Implement support for DSM_PAPR_SCM_HEALTH

["Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>]

Vaibhav Jain <vaibhav@linux.ibm.com> writes:

> 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.
>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Changelog:
>
> v4..v5: None
>
> v3..v4: Call the DSM_PAPR_SCM_HEALTH service function from
> 	papr_scm_service_dsm() instead of papr_scm_ndctl(). [Aneesh]
>
> 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    | 109 ++++++++++++++++---
>  2 files changed, 132 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 e8ce96d2249e..ce94762954e0 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;
> @@ -331,6 +359,51 @@ static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
>  	return 0;
>  }
>  
> +/* 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;
> +}
> +
>  static int papr_scm_service_dsm(struct papr_scm_priv *p,
>  				struct nd_papr_scm_cmd_pkg *call_pkg)
>  {
> @@ -345,6 +418,9 @@ static int papr_scm_service_dsm(struct papr_scm_priv *p,
>  
>  	/* Depending on the DSM command call appropriate service routine */
>  	switch (call_pkg->hdr.nd_command) {
> +	case DSM_PAPR_SCM_HEALTH:
> +		return papr_scm_get_health(p, call_pkg);
> +
>  	default:
>  		pr_debug("Unsupported DSM command 0x%llx\n",
>  			 call_pkg->hdr.nd_command);
> @@ -431,7 +507,6 @@ 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);
> @@ -443,26 +518,26 @@ 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");
> -- 
> 2.25.1
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