[PATCH v5 1/4] powerpc/papr_scm: Fetch nvdimm health information from PHYP
Aneesh Kumar K.V
aneesh.kumar at linux.ibm.com
Wed Apr 1 16:30:16 AEDT 2020
Vaibhav Jain <vaibhav at linux.ibm.com> writes:
> Implement support for fetching nvdimm health information via
> H_SCM_HEALTH hcall as documented in Ref[1]. The hcall returns a pair
> of 64-bit big-endian integers which are then stored in 'struct
> papr_scm_priv' and subsequently partially exposed to user-space via
> newly introduced dimm specific attribute 'papr_flags'. Also a new asm
> header named 'papr-scm.h' is added that describes the interface
> between PHYP and guest kernel.
>
> Following flags are reported via 'papr_flags' sysfs attribute contents
> of which are space separated string flags indicating various nvdimm
> states:
>
> * "not_armed" : Indicating that nvdimm contents wont survive a power
> cycle.
> * "save_fail" : Indicating that nvdimm contents couldn't be flushed
> during last shutdown event.
> * "restore_fail": Indicating that nvdimm contents couldn't be restored
> during dimm initialization.
> * "encrypted" : Dimm contents are encrypted.
> * "smart_notify": There is health event for the nvdimm.
> * "scrubbed" : Indicating that contents of the nvdimm have been
> scrubbed.
> * "locked" : Indicating that nvdimm contents cant be modified
> until next power cycle.
>
> [1]: commit 58b278f568f0 ("powerpc: Provide initial documentation for
> PAPR hcalls")
>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
> Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>
> ---
> Changelog:
>
> v4..v5 : None
>
> v3..v4 : None
>
> v2..v3 : Removed PAPR_SCM_DIMM_HEALTH_NON_CRITICAL as a condition for
> NVDIMM unarmed [Aneesh]
>
> v1..v2 : New patch in the series.
> ---
> arch/powerpc/include/asm/papr_scm.h | 48 ++++++++++
> arch/powerpc/platforms/pseries/papr_scm.c | 105 +++++++++++++++++++++-
> 2 files changed, 151 insertions(+), 2 deletions(-)
> create mode 100644 arch/powerpc/include/asm/papr_scm.h
>
> diff --git a/arch/powerpc/include/asm/papr_scm.h b/arch/powerpc/include/asm/papr_scm.h
> new file mode 100644
> index 000000000000..868d3360f56a
> --- /dev/null
> +++ b/arch/powerpc/include/asm/papr_scm.h
> @@ -0,0 +1,48 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Structures and defines needed to manage nvdimms for spapr guests.
> + */
> +#ifndef _ASM_POWERPC_PAPR_SCM_H_
> +#define _ASM_POWERPC_PAPR_SCM_H_
> +
> +#include <linux/types.h>
> +#include <asm/bitsperlong.h>
> +
> +/* DIMM health bitmap bitmap indicators */
> +/* SCM device is unable to persist memory contents */
> +#define PAPR_SCM_DIMM_UNARMED PPC_BIT(0)
> +/* SCM device failed to persist memory contents */
> +#define PAPR_SCM_DIMM_SHUTDOWN_DIRTY PPC_BIT(1)
> +/* SCM device contents are persisted from previous IPL */
> +#define PAPR_SCM_DIMM_SHUTDOWN_CLEAN PPC_BIT(2)
> +/* SCM device contents are not persisted from previous IPL */
> +#define PAPR_SCM_DIMM_EMPTY PPC_BIT(3)
> +/* SCM device memory life remaining is critically low */
> +#define PAPR_SCM_DIMM_HEALTH_CRITICAL PPC_BIT(4)
> +/* SCM device will be garded off next IPL due to failure */
> +#define PAPR_SCM_DIMM_HEALTH_FATAL PPC_BIT(5)
> +/* SCM contents cannot persist due to current platform health status */
> +#define PAPR_SCM_DIMM_HEALTH_UNHEALTHY PPC_BIT(6)
> +/* SCM device is unable to persist memory contents in certain conditions */
> +#define PAPR_SCM_DIMM_HEALTH_NON_CRITICAL PPC_BIT(7)
> +/* SCM device is encrypted */
> +#define PAPR_SCM_DIMM_ENCRYPTED PPC_BIT(8)
> +/* SCM device has been scrubbed and locked */
> +#define PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED PPC_BIT(9)
> +
> +/* Bits status indicators for health bitmap indicating unarmed dimm */
> +#define PAPR_SCM_DIMM_UNARMED_MASK (PAPR_SCM_DIMM_UNARMED | \
> + PAPR_SCM_DIMM_HEALTH_UNHEALTHY)
> +
> +/* Bits status indicators for health bitmap indicating unflushed dimm */
> +#define PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK (PAPR_SCM_DIMM_SHUTDOWN_DIRTY)
> +
> +/* Bits status indicators for health bitmap indicating unrestored dimm */
> +#define PAPR_SCM_DIMM_BAD_RESTORE_MASK (PAPR_SCM_DIMM_EMPTY)
> +
> +/* Bit status indicators for smart event notification */
> +#define PAPR_SCM_DIMM_SMART_EVENT_MASK (PAPR_SCM_DIMM_HEALTH_CRITICAL | \
> + PAPR_SCM_DIMM_HEALTH_FATAL | \
> + PAPR_SCM_DIMM_HEALTH_UNHEALTHY)
> +
> +#endif
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index 0b4467e378e5..aaf2e4ab1f75 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -14,6 +14,7 @@
> #include <linux/delay.h>
>
> #include <asm/plpar_wrappers.h>
> +#include <asm/papr_scm.h>
>
> #define BIND_ANY_ADDR (~0ul)
>
> @@ -39,6 +40,13 @@ struct papr_scm_priv {
> struct resource res;
> struct nd_region *region;
> struct nd_interleave_set nd_set;
> +
> + /* Protect dimm data from concurrent access */
> + struct mutex dimm_mutex;
> +
> + /* Health information for the dimm */
> + __be64 health_bitmap;
> + __be64 health_bitmap_valid;
> };
>
> static int drc_pmem_bind(struct papr_scm_priv *p)
> @@ -144,6 +152,35 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
> return drc_pmem_bind(p);
> }
>
> +static int drc_pmem_query_health(struct papr_scm_priv *p)
> +{
> + unsigned long ret[PLPAR_HCALL_BUFSIZE];
> + int64_t rc;
> +
> + rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
> + if (rc != H_SUCCESS) {
> + dev_err(&p->pdev->dev,
> + "Failed to query health information, Err:%lld\n", rc);
> + return -ENXIO;
> + }
> +
> + /* Protect modifications to papr_scm_priv with the mutex */
> + rc = mutex_lock_interruptible(&p->dimm_mutex);
> + if (rc)
> + return rc;
> +
> + /* Store the retrieved health information in dimm platform data */
> + p->health_bitmap = ret[0];
> + p->health_bitmap_valid = 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));
> +
> + mutex_unlock(&p->dimm_mutex);
> + return 0;
> +}
>
> static int papr_scm_meta_get(struct papr_scm_priv *p,
> struct nd_cmd_get_config_data_hdr *hdr)
> @@ -304,6 +341,67 @@ static inline int papr_scm_node(int node)
> return min_node;
> }
>
> +static ssize_t papr_flags_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + 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);
> + if (rc)
> + return rc;
> +
> + /* Protect against modifications to papr_scm_priv with the mutex */
> + rc = mutex_lock_interruptible(&p->dimm_mutex);
> + 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)
> + rc += sprintf(buf, "not_armed ");
> +
> + if (health & PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK)
> + rc += sprintf(buf + rc, "save_fail ");
> +
> + if (health & PAPR_SCM_DIMM_BAD_RESTORE_MASK)
> + rc += sprintf(buf + rc, "restore_fail ");
> +
> + if (health & PAPR_SCM_DIMM_ENCRYPTED)
> + rc += sprintf(buf + rc, "encrypted ");
> +
> + if (health & PAPR_SCM_DIMM_SMART_EVENT_MASK)
> + rc += sprintf(buf + rc, "smart_notify ");
> +
> + if (health & PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED)
> + rc += sprintf(buf + rc, "scrubbed locked ");
> +
> + if (rc > 0)
> + rc += sprintf(buf + rc, "\n");
> +
> + mutex_unlock(&p->dimm_mutex);
> + return rc;
> +}
> +DEVICE_ATTR_RO(papr_flags);
> +
> +/* papr_scm specific dimm attributes */
> +static struct attribute *papr_scm_nd_attributes[] = {
> + &dev_attr_papr_flags.attr,
> + NULL,
> +};
> +
> +static struct attribute_group papr_scm_nd_attribute_group = {
> + .attrs = papr_scm_nd_attributes,
> +};
> +
> +static const struct attribute_group *papr_scm_dimm_attr_groups[] = {
> + &papr_scm_nd_attribute_group,
> + NULL,
> +};
> +
> static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
> {
> struct device *dev = &p->pdev->dev;
> @@ -330,8 +428,8 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
> dimm_flags = 0;
> set_bit(NDD_ALIASING, &dimm_flags);
>
> - p->nvdimm = nvdimm_create(p->bus, p, NULL, dimm_flags,
> - PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
> + p->nvdimm = nvdimm_create(p->bus, p, papr_scm_dimm_attr_groups,
> + dimm_flags, PAPR_SCM_DIMM_CMD_MASK, 0, NULL);
> if (!p->nvdimm) {
> dev_err(dev, "Error creating DIMM object for %pOF\n", p->dn);
> goto err;
> @@ -415,6 +513,9 @@ static int papr_scm_probe(struct platform_device *pdev)
> if (!p)
> return -ENOMEM;
>
> + /* Initialize the dimm mutex */
> + mutex_init(&p->dimm_mutex);
> +
> /* optional DT properties */
> of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
>
> --
> 2.25.1
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