// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) "papr-scm: " fmt
#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/ndctl.h>
#include <linux/sched.h>
#include <linux/libnvdimm.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/seq_buf.h>
#include <linux/nd.h>
#include <asm/plpar_wrappers.h>
#include <uapi/linux/papr_pdsm.h>
#include <linux/papr_scm.h>
#include <asm/mce.h>
#include <asm/unaligned.h>
#include <linux/perf_event.h>
#define BIND_ANY_ADDR (~0ul)
#define PAPR_SCM_DIMM_CMD_MASK \
((1ul << ND_CMD_GET_CONFIG_SIZE) | \
(1ul << ND_CMD_GET_CONFIG_DATA) | \
(1ul << ND_CMD_SET_CONFIG_DATA) | \
(1ul << ND_CMD_CALL))
/* Struct holding a single performance metric */
struct papr_scm_perf_stat {
u8 stat_id[8];
__be64 stat_val;
} __packed;
/* Struct exchanged between kernel and PHYP for fetching drc perf stats */
struct papr_scm_perf_stats {
u8 eye_catcher[8];
/* Should be PAPR_SCM_PERF_STATS_VERSION */
__be32 stats_version;
/* Number of stats following */
__be32 num_statistics;
/* zero or more performance matrics */
struct papr_scm_perf_stat scm_statistic[];
} __packed;
/* private struct associated with each region */
struct papr_scm_priv {
struct platform_device *pdev;
struct device_node *dn;
uint32_t drc_index;
uint64_t blocks;
uint64_t block_size;
int metadata_size;
bool is_volatile;
bool hcall_flush_required;
uint64_t bound_addr;
struct nvdimm_bus_descriptor bus_desc;
struct nvdimm_bus *bus;
struct nvdimm *nvdimm;
struct resource res;
struct nd_region *region;
struct nd_interleave_set nd_set;
struct list_head region_list;
/* Protect dimm health data from concurrent read/writes */
struct mutex health_mutex;
/* Last time the health information of the dimm was updated */
unsigned long lasthealth_jiffies;
/* Health information for the dimm */
u64 health_bitmap;
/* Holds the last known dirty shutdown counter value */
u64 dirty_shutdown_counter;
/* length of the stat buffer as expected by phyp */
size_t stat_buffer_len;
/* The bits which needs to be overridden */
u64 health_bitmap_inject_mask;
};
static int papr_scm_pmem_flush(struct nd_region *nd_region,
struct bio *bio __maybe_unused)
{
struct papr_scm_priv *p = nd_region_provider_data(nd_region);
unsigned long ret_buf[PLPAR_HCALL_BUFSIZE], token = 0;
long rc;
dev_dbg(&p->pdev->dev, "flush drc 0x%x", p->drc_index);
do {
rc = plpar_hcall(H_SCM_FLUSH, ret_buf, p->drc_index, token);
token = ret_buf[0];
/* Check if we are stalled for some time */
if (H_IS_LONG_BUSY(rc)) {
msleep(get_longbusy_msecs(rc));
rc = H_BUSY;
} else if (rc == H_BUSY) {
cond_resched();
}
} while (rc == H_BUSY);
if (rc) {
dev_err(&p->pdev->dev, "flush error: %ld", rc);
rc = -EIO;
} else {
dev_dbg(&p->pdev->dev, "flush drc 0x%x complete", p->drc_index);
}
return rc;
}
static LIST_HEAD(papr_nd_regions);
static DEFINE_MUTEX(papr_ndr_lock);
static int drc_pmem_bind(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
uint64_t saved = 0;
uint64_t token;
int64_t rc;
/*
* When the hypervisor cannot map all the requested memory in a single
* hcall it returns H_BUSY and we call again with the token until
* we get H_SUCCESS. Aborting the retry loop before getting H_SUCCESS
* leave the system in an undefined state, so we wait.
*/
token = 0;
do {
rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
p->blocks, BIND_ANY_ADDR, token);
token = ret[0];
if (!saved)
saved = ret[1];
cond_resched();
} while (rc == H_BUSY);
if (rc)
return rc;
p->bound_addr = saved;
dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n",
p->drc_index, (unsigned long)saved);
return rc;
}
static void drc_pmem_unbind(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
uint64_t token = 0;
int64_t rc;
dev_dbg(&p->pdev->dev, "unbind drc 0x%x\n", p->drc_index);
/* NB: unbind has the same retry requirements as drc_pmem_bind() */
do {
/* Unbind of all SCM resources associated with drcIndex */
rc = plpar_hcall(H_SCM_UNBIND_ALL, ret, H_UNBIND_SCOPE_DRC,
p->drc_index, token);
token = ret[0];
/* Check if we are stalled for some time */
if (H_IS_LONG_BUSY(rc)) {
msleep(get_longbusy_msecs(rc));
rc = H_BUSY;
} else if (rc == H_BUSY) {
cond_resched();
}
} while (rc == H_BUSY);
if (rc)
dev_err(&p->pdev->dev, "unbind error: %lld\n", rc);
else
dev_dbg(&p->pdev->dev, "unbind drc 0x%x complete\n",
p->drc_index);
return;
}
static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
{
unsigned long start_addr;
unsigned long end_addr;
unsigned long ret[PLPAR_HCALL_BUFSIZE];
int64_t rc;
rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
p->drc_index, 0);
if (rc)
goto err_out;
start_addr = ret[0];
/* Make sure the full region is bound. */
rc = plpar_hcall(H_SCM_QUERY_BLOCK_MEM_BINDING, ret,
p->drc_index, p->blocks - 1);
if (rc)
goto err_out;
end_addr = ret[0];
if ((end_addr - start_addr) != ((p->blocks - 1) * p->block_size))
goto err_out;
p->bound_addr = start_addr;
dev_dbg(&p->pdev->dev, "bound drc 0x%x to 0x%lx\n", p->drc_index, start_addr);
return rc;
err_out:
dev_info(&p->pdev->dev,
"Failed to query, trying an unbind followed by bind");
drc_pmem_unbind(p);
return drc_pmem_bind(p);
}
/*
* Query the Dimm performance stats from PHYP and copy them (if returned) to
* provided struct papr_scm_perf_stats instance 'stats' that can hold atleast
* (num_stats + header) bytes.
* - If buff_stats == NULL the return value is the size in bytes of the buffer
* needed to hold all supported performance-statistics.
* - If buff_stats != NULL and num_stats == 0 then we copy all known
* performance-statistics to 'buff_stat' and expect to be large enough to
* hold them.
* - if buff_stats != NULL and num_stats > 0 then copy the requested
* performance-statistics to buff_stats.
*/
static ssize_t drc_pmem_query_stats(struct papr_scm_priv *p,
struct papr_scm_perf_stats *buff_stats,
unsigned int num_stats)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
size_t size;
s64 rc;
/* Setup the out buffer */
if (buff_stats) {
memcpy(buff_stats->eye_catcher,
PAPR_SCM_PERF_STATS_EYECATCHER, 8);
buff_stats->stats_version =
cpu_to_be32(PAPR_SCM_PERF_STATS_VERSION);
buff_stats->num_statistics =
cpu_to_be32(num_stats);
/*
* Calculate the buffer size based on num-stats provided
* or use the prefetched max buffer length
*/
if (num_stats)
/* Calculate size from the num_stats */
size = sizeof(struct papr_scm_perf_stats) +
num_stats * sizeof(struct papr_scm_perf_stat);
else
size = p->stat_buffer_len;
} else {
/* In case of no out buffer ignore the size */
size = 0;
}
/* Do the HCALL asking PHYP for info */
rc = plpar_hcall(H_SCM_PERFORMANCE_STATS, ret, p->drc_index,
buff_stats ? virt_to_phys(buff_stats) : 0,
size);
/* Check if the error was due to an unknown stat-id */
if (rc == H_PARTIAL) {
dev_err(&p->pdev->dev,
"Unknown performance stats, Err:0x%016lX\n", ret[0]);
return -ENOENT;
} else if (rc == H_AUTHORITY) {
dev_info(&p->pdev->dev,
"Permission denied while accessing performance stats");
return -EPERM;
} else if (rc == H_UNSUPPORTED) {
dev_dbg(&p->pdev->dev, "Performance stats unsupported\n");
return -EOPNOTSUPP;
} else if (rc != H_SUCCESS) {
dev_err(&p->pdev->dev,
"Failed to query performance stats, Err:%lld\n", rc);
return -EIO;
} else if (!size) {
/* Handle case where stat buffer size was requested */
dev_dbg(&p->pdev->dev,
"Performance stats size %ld\n", ret[0]);
return ret[0];
}
/* Successfully fetched the requested stats from phyp */
dev_dbg(&p->pdev->dev,
"Performance stats returned %d stats\n",
be32_to_cpu(buff_stats->num_statistics));
return 0;
}
#ifdef CONFIG_PERF_EVENTS
#define to_nvdimm_pmu(_pmu) container_of(_pmu, struct nvdimm_pmu, pmu)
static const char * const nvdimm_events_map[] = {
[1] = "CtlResCt",
[2] = "CtlResTm",
[3] = "PonSecs ",
[4] = "MemLife ",
[5] = "CritRscU",
[6] = "HostLCnt",
[7] = "HostSCnt",
[8] = "HostSDur",
[9] = "HostLDur",
[10] = "MedRCnt ",
[11] = "MedWCnt ",
[12] = "MedRDur ",
[13] = "MedWDur ",
[14] = "CchRHCnt",
[15] = "CchWHCnt",
[16] = "FastWCnt",
};
static int papr_scm_pmu_get_value(struct perf_event *event, struct device *dev, u64 *count)
{
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
struct papr_scm_priv *p = dev_get_drvdata(dev);
int rc, size;
/* Invalid eventcode */
if (event->attr.config == 0 || event->attr.config >= ARRAY_SIZE(nvdimm_events_map))
return -EINVAL;
/* Allocate request buffer enough to hold single performance stat */
size = sizeof(struct papr_scm_perf_stats) +
sizeof(struct papr_scm_perf_stat);
if (!p)
return -EINVAL;
stats = kzalloc(size, GFP_KERNEL);
if (!stats)
return -ENOMEM;
stat = &stats->scm_statistic[0];
memcpy(&stat->stat_id,
nvdimm_events_map[event->attr.config],
sizeof(stat->stat_id));
stat->stat_val = 0;
rc = drc_pmem_query_stats(p, stats, 1);
if (rc < 0) {
kfree(stats);
return rc;
}
*count = be64_to_cpu(stat->stat_val);
kfree(stats);
return 0;
}
static int papr_scm_pmu_event_init(struct perf_event *event)
{
struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
struct papr_scm_priv *p;
if (!nd_pmu)
return -EINVAL;
/* test the event attr type for PMU enumeration */
if (event->attr.type != event->pmu->type)
return -ENOENT;
/* it does not support event sampling mode */
if (is_sampling_event(event))
return -EOPNOTSUPP;
/* no branch sampling */
if (has_branch_stack(event))
return -EOPNOTSUPP;
p = (struct papr_scm_priv *)nd_pmu->dev->driver_data;
if (!p)
return -EINVAL;
/* Invalid eventcode */
if (event->attr.config == 0 || event->attr.config > 16)
return -EINVAL;
return 0;
}
static int papr_scm_pmu_add(struct perf_event *event, int flags)
{
u64 count;
int rc;
struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
if (!nd_pmu)
return -EINVAL;
if (flags & PERF_EF_START) {
rc = papr_scm_pmu_get_value(event, nd_pmu->dev, &count);
if (rc)
return rc;
local64_set(&event->hw.prev_count, count);
}
return 0;
}
static void papr_scm_pmu_read(struct perf_event *event)
{
u64 prev, now;
int rc;
struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu);
if (!nd_pmu)
return;
rc = papr_scm_pmu_get_value(event, nd_pmu->dev, &now);
if (rc)
return;
prev = local64_xchg(&event->hw.prev_count, now);
local64_add(now - prev, &event->count);
}
static void papr_scm_pmu_del(struct perf_event *event, int flags)
{
papr_scm_pmu_read(event);
}
static void papr_scm_pmu_register(struct papr_scm_priv *p)
{
struct nvdimm_pmu *nd_pmu;
int rc, nodeid;
nd_pmu = kzalloc(sizeof(*nd_pmu), GFP_KERNEL);
if (!nd_pmu) {
rc = -ENOMEM;
goto pmu_err_print;
}
if (!p->stat_buffer_len) {
rc = -ENOENT;
goto pmu_check_events_err;
}
nd_pmu->pmu.task_ctx_nr = perf_invalid_context;
nd_pmu->pmu.name = nvdimm_name(p->nvdimm);
nd_pmu->pmu.event_init = papr_scm_pmu_event_init;
nd_pmu->pmu.read = papr_scm_pmu_read;
nd_pmu->pmu.add = papr_scm_pmu_add;
nd_pmu->pmu.del = papr_scm_pmu_del;
nd_pmu->pmu.capabilities = PERF_PMU_CAP_NO_INTERRUPT |
PERF_PMU_CAP_NO_EXCLUDE;
/*updating the cpumask variable */
nodeid = numa_map_to_online_node(dev_to_node(&p->pdev->dev));
nd_pmu->arch_cpumask = *cpumask_of_node(nodeid);
rc = register_nvdimm_pmu(nd_pmu, p->pdev);
if (rc)
goto pmu_check_events_err;
/*
* Set archdata.priv value to nvdimm_pmu structure, to handle the
* unregistering of pmu device.
*/
p->pdev->archdata.priv = nd_pmu;
return;
pmu_check_events_err:
kfree(nd_pmu);
pmu_err_print:
dev_info(&p->pdev->dev, "nvdimm pmu didn't register rc=%d\n", rc);
}
#else
static void papr_scm_pmu_register(struct papr_scm_priv *p) { }
#endif
/*
* Issue hcall to retrieve dimm health info and populate papr_scm_priv with the
* health information.
*/
static int __drc_pmem_query_health(struct papr_scm_priv *p)
{
unsigned long ret[PLPAR_HCALL_BUFSIZE];
u64 bitmap = 0;
long rc;
/* issue the hcall */
rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
if (rc == H_SUCCESS)
bitmap = ret[0] & ret[1];
else if (rc == H_FUNCTION)
dev_info_once(&p->pdev->dev,
"Hcall H_SCM_HEALTH not implemented, assuming empty health bitmap");
else {
dev_err(&p->pdev->dev,
"Failed to query health information, Err:%ld\n", rc);
return -ENXIO;
}
p->lasthealth_jiffies = jiffies;
/* Allow injecting specific health bits via inject mask. */
if (p->health_bitmap_inject_mask)
bitmap = (bitmap & ~p->health_bitmap_inject_mask) |
p->health_bitmap_inject_mask;
WRITE_ONCE(p->health_bitmap, bitmap);
dev_dbg(&p->pdev->dev,
"Queried dimm health info. Bitmap:0x%016lx Mask:0x%016lx\n",
ret[0], ret[1]);
return 0;
}
/* Min interval in seconds for assuming stable dimm health */
#define MIN_HEALTH_QUERY_INTERVAL 60
/* Query cached health info and if needed call drc_pmem_query_health */
static int drc_pmem_query_health(struct papr_scm_priv *p)
{
unsigned long cache_timeout;
int rc;
/* Protect concurrent modifications to papr_scm_priv */
rc = mutex_lock_interruptible(&p->health_mutex);
if (rc)
return rc;
/* Jiffies offset for which the health data is assumed to be same */
cache_timeout = p->lasthealth_jiffies +
msecs_to_jiffies(MIN_HEALTH_QUERY_INTERVAL * 1000);
/* Fetch new health info is its older than MIN_HEALTH_QUERY_INTERVAL */
if (time_after(jiffies, cache_timeout))
rc = __drc_pmem_query_health(p);
else
/* Assume cached health data is valid */
rc = 0;
mutex_unlock(&p->health_mutex);
return rc;
}
static int papr_scm_meta_get(struct papr_scm_priv *p,
struct nd_cmd_get_config_data_hdr *hdr)
{
unsigned long data[PLPAR_HCALL_BUFSIZE];
unsigned long offset, data_offset;
int len, read;
int64_t ret;
if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
return -EINVAL;
for (len = hdr->in_length; len; len -= read) {
data_offset = hdr->in_length - len;
offset = hdr->in_offset + data_offset;
if (len >= 8)
read = 8;
else if (len >= 4)
read = 4;
else if (len >= 2)
read = 2;
else
read = 1;
ret = plpar_hcall(H_SCM_READ_METADATA, data, p->drc_index,
offset, read);
if (ret == H_PARAMETER) /* bad DRC index */
return -ENODEV;
if (ret)
return -EINVAL; /* other invalid parameter */
switch (read) {
case 8:
*(uint64_t *)(hdr->out_buf + data_offset) = be64_to_cpu(data[0]);
break;
case 4:
*(uint32_t *)(hdr->out_buf + data_offset) = be32_to_cpu(data[0] & 0xffffffff);
break;
case 2:
*(uint16_t *)(hdr->out_buf + data_offset) = be16_to_cpu(data[0] & 0xffff);
break;
case 1:
*(uint8_t *)(hdr->out_buf + data_offset) = (data[0] & 0xff);
break;
}
}
return 0;
}
static int papr_scm_meta_set(struct papr_scm_priv *p,
struct nd_cmd_set_config_hdr *hdr)
{
unsigned long offset, data_offset;
int len, wrote;
unsigned long data;
__be64 data_be;
int64_t ret;
if ((hdr->in_offset + hdr->in_length) > p->metadata_size)
return -EINVAL;
for (len = hdr->in_length; len; len -= wrote) {
data_offset = hdr->in_length - len;
offset = hdr->in_offset + data_offset;
if (len >= 8) {
data = *(uint64_t *)(hdr->in_buf + data_offset);
data_be = cpu_to_be64(data);
wrote = 8;
} else if (len >= 4) {
data = *(uint32_t *)(hdr->in_buf + data_offset);
data &= 0xffffffff;
data_be = cpu_to_be32(data);
wrote = 4;
} else if (len >= 2) {
data = *(uint16_t *)(hdr->in_buf + data_offset);
data &= 0xffff;
data_be = cpu_to_be16(data);
wrote = 2;
} else {
data_be = *(uint8_t *)(hdr->in_buf + data_offset);
data_be &= 0xff;
wrote = 1;
}
ret = plpar_hcall_norets(H_SCM_WRITE_METADATA, p->drc_index,
offset, data_be, wrote);
if (ret == H_PARAMETER) /* bad DRC index */
return -ENODEV;
if (ret)
return -EINVAL; /* other invalid parameter */
}
return 0;
}
/*
* Do a sanity checks on the inputs args to dimm-control function and return
* '0' if valid. Validation of PDSM payloads happens later in
* papr_scm_service_pdsm.
*/
static int is_cmd_valid(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
unsigned int buf_len)
{
unsigned long cmd_mask = PAPR_SCM_DIMM_CMD_MASK;
struct nd_cmd_pkg *nd_cmd;
struct papr_scm_priv *p;
enum papr_pdsm pdsm;
/* Only dimm-specific calls are supported atm */
if (!nvdimm)
return -EINVAL;
/* get the provider data from struct nvdimm */
p = nvdimm_provider_data(nvdimm);
if (!test_bit(cmd, &cmd_mask)) {
dev_dbg(&p->pdev->dev, "Unsupported cmd=%u\n", cmd);
return -EINVAL;
}
/* For CMD_CALL verify pdsm request */
if (cmd == ND_CMD_CALL) {
/* Verify the envelope and envelop size */
if (!buf ||
buf_len < (sizeof(struct nd_cmd_pkg) + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "Invalid pkg size=%u\n",
buf_len);
return -EINVAL;
}
/* Verify that the nd_cmd_pkg.nd_family is correct */
nd_cmd = (struct nd_cmd_pkg *)buf;
if (nd_cmd->nd_family != NVDIMM_FAMILY_PAPR) {
dev_dbg(&p->pdev->dev, "Invalid pkg family=0x%llx\n",
nd_cmd->nd_family);
return -EINVAL;
}
pdsm = (enum papr_pdsm)nd_cmd->nd_command;
/* Verify if the pdsm command is valid */
if (pdsm <= PAPR_PDSM_MIN || pdsm >= PAPR_PDSM_MAX) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid PDSM\n",
pdsm);
return -EINVAL;
}
/* Have enough space to hold returned 'nd_pkg_pdsm' header */
if (nd_cmd->nd_size_out < ND_PDSM_HDR_SIZE) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid payload\n",
pdsm);
return -EINVAL;
}
}
/* Let the command be further processed */
return 0;
}
static int papr_pdsm_fuel_gauge(struct papr_scm_priv *p,
union nd_pdsm_payload *payload)
{
int rc, size;
u64 statval;
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
/* Silently fail if fetching performance metrics isn't supported */
if (!p->stat_buffer_len)
return 0;
/* Allocate request buffer enough to hold single performance stat */
size = sizeof(struct papr_scm_perf_stats) +
sizeof(struct papr_scm_perf_stat);
stats = kzalloc(size, GFP_KERNEL);
if (!stats)
return -ENOMEM;
stat = &stats->scm_statistic[0];
memcpy(&stat->stat_id, "MemLife ", sizeof(stat->stat_id));
stat->stat_val = 0;
/* Fetch the fuel gauge and populate it in payload */
rc = drc_pmem_query_stats(p, stats, 1);
if (rc < 0) {
dev_dbg(&p->pdev->dev, "Err(%d) fetching fuel gauge\n", rc);
goto free_stats;
}
statval = be64_to_cpu(stat->stat_val);
dev_dbg(&p->pdev->dev,
"Fetched fuel-gauge %llu", statval);
payload->health.extension_flags |=
PDSM_DIMM_HEALTH_RUN_GAUGE_VALID;
payload->health.dimm_fuel_gauge = statval;
rc = sizeof(struct nd_papr_pdsm_health);
free_stats:
kfree(stats);
return rc;
}
/* Add the dirty-shutdown-counter value to the pdsm */
static int papr_pdsm_dsc(struct papr_scm_priv *p,
union nd_pdsm_payload *payload)
{
payload->health.extension_flags |= PDSM_DIMM_DSC_VALID;
payload->health.dimm_dsc = p->dirty_shutdown_counter;
return sizeof(struct nd_papr_pdsm_health);
}
/* Fetch the DIMM health info and populate it in provided package. */
static int papr_pdsm_health(struct papr_scm_priv *p,
union nd_pdsm_payload *payload)
{
int rc;
/* Ensure dimm health mutex is taken preventing concurrent access */
rc = mutex_lock_interruptible(&p->health_mutex);
if (rc)
goto out;
/* Always fetch upto date dimm health data ignoring cached values */
rc = __drc_pmem_query_health(p);
if (rc) {
mutex_unlock(&p->health_mutex);
goto out;
}
/* update health struct with various flags derived from health bitmap */
payload->health = (struct nd_papr_pdsm_health) {
.extension_flags = 0,
.dimm_unarmed = !!(p->health_bitmap & PAPR_PMEM_UNARMED_MASK),
.dimm_bad_shutdown = !!(p->health_bitmap & PAPR_PMEM_BAD_SHUTDOWN_MASK),
.dimm_bad_restore = !!(p->health_bitmap & PAPR_PMEM_BAD_RESTORE_MASK),
.dimm_scrubbed = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
.dimm_locked = !!(p->health_bitmap & PAPR_PMEM_SCRUBBED_AND_LOCKED),
.dimm_encrypted = !!(p->health_bitmap & PAPR_PMEM_ENCRYPTED),
.dimm_health = PAPR_PDSM_DIMM_HEALTHY,
};
/* Update field dimm_health based on health_bitmap flags */
if (p->health_bitmap & PAPR_PMEM_HEALTH_FATAL)
payload->health.dimm_health = PAPR_PDSM_DIMM_FATAL;
else if (p->health_bitmap & PAPR_PMEM_HEALTH_CRITICAL)
payload->health.dimm_health = PAPR_PDSM_DIMM_CRITICAL;
else if (p->health_bitmap & PAPR_PMEM_HEALTH_UNHEALTHY)
payload->health.dimm_health = PAPR_PDSM_DIMM_UNHEALTHY;
/* struct populated hence can release the mutex now */
mutex_unlock(&p->health_mutex);
/* Populate the fuel gauge meter in the payload */
papr_pdsm_fuel_gauge(p, payload);
/* Populate the dirty-shutdown-counter field */
papr_pdsm_dsc(p, payload);
rc = sizeof(struct nd_papr_pdsm_health);
out:
return rc;
}
/* Inject a smart error Add the dirty-shutdown-counter value to the pdsm */
static int papr_pdsm_smart_inject(struct papr_scm_priv *p,
union nd_pdsm_payload *payload)
{
int rc;
u32 supported_flags = 0;
u64 inject_mask = 0, clear_mask = 0;
u64 mask;
/* Check for individual smart error flags and update inject/clear masks */
if (payload->smart_inject.flags & PDSM_SMART_INJECT_HEALTH_FATAL) {
supported_flags |= PDSM_SMART_INJECT_HEALTH_FATAL;
if (payload->smart_inject.fatal_enable)
inject_mask |= PAPR_PMEM_HEALTH_FATAL;
else
clear_mask |= PAPR_PMEM_HEALTH_FATAL;
}
if (payload->smart_inject.flags & PDSM_SMART_INJECT_BAD_SHUTDOWN) {
supported_flags |= PDSM_SMART_INJECT_BAD_SHUTDOWN;
if (payload->smart_inject.unsafe_shutdown_enable)
inject_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
else
clear_mask |= PAPR_PMEM_SHUTDOWN_DIRTY;
}
dev_dbg(&p->pdev->dev, "[Smart-inject] inject_mask=%#llx clear_mask=%#llx\n",
inject_mask, clear_mask);
/* Prevent concurrent access to dimm health bitmap related members */
rc = mutex_lock_interruptible(&p->health_mutex);
if (rc)
return rc;
/* Use inject/clear masks to set health_bitmap_inject_mask */
mask = READ_ONCE(p->health_bitmap_inject_mask);
mask = (mask & ~clear_mask) | inject_mask;
WRITE_ONCE(p->health_bitmap_inject_mask, mask);
/* Invalidate cached health bitmap */
p->lasthealth_jiffies = 0;
mutex_unlock(&p->health_mutex);
/* Return the supported flags back to userspace */
payload->smart_inject.flags = supported_flags;
return sizeof(struct nd_papr_pdsm_health);
}
/*
* 'struct pdsm_cmd_desc'
* Identifies supported PDSMs' expected length of in/out payloads
* and pdsm service function.
*
* size_in : Size of input payload if any in the PDSM request.
* size_out : Size of output payload if any in the PDSM request.
* service : Service function for the PDSM request. Return semantics:
* rc < 0 : Error servicing PDSM and rc indicates the error.
* rc >=0 : Serviced successfully and 'rc' indicate number of
* bytes written to payload.
*/
struct pdsm_cmd_desc {
u32 size_in;
u32 size_out;
int (*service)(struct papr_scm_priv *dimm,
union nd_pdsm_payload *payload);
};
/* Holds all supported PDSMs' command descriptors */
static const struct pdsm_cmd_desc __pdsm_cmd_descriptors[] = {
[PAPR_PDSM_MIN] = {
.size_in = 0,
.size_out = 0,
.service = NULL,
},
/* New PDSM command descriptors to be added below */
[PAPR_PDSM_HEALTH] = {
.size_in = 0,
.size_out = sizeof(struct nd_papr_pdsm_health),
.service = papr_pdsm_health,
},
[PAPR_PDSM_SMART_INJECT] = {
.size_in = sizeof(struct nd_papr_pdsm_smart_inject),
.size_out = sizeof(struct nd_papr_pdsm_smart_inject),
.service = papr_pdsm_smart_inject,
},
/* Empty */
[PAPR_PDSM_MAX] = {
.size_in = 0,
.size_out = 0,
.service = NULL,
},
};
/* Given a valid pdsm cmd return its command descriptor else return NULL */
static inline const struct pdsm_cmd_desc *pdsm_cmd_desc(enum papr_pdsm cmd)
{
if (cmd >= 0 || cmd < ARRAY_SIZE(__pdsm_cmd_descriptors))
return &__pdsm_cmd_descriptors[cmd];
return NULL;
}
/*
* For a given pdsm request call an appropriate service function.
* Returns errors if any while handling the pdsm command package.
*/
static int papr_scm_service_pdsm(struct papr_scm_priv *p,
struct nd_cmd_pkg *pkg)
{
/* Get the PDSM header and PDSM command */
struct nd_pkg_pdsm *pdsm_pkg = (struct nd_pkg_pdsm *)pkg->nd_payload;
enum papr_pdsm pdsm = (enum papr_pdsm)pkg->nd_command;
const struct pdsm_cmd_desc *pdsc;
int rc;
/* Fetch corresponding pdsm descriptor for validation and servicing */
pdsc = pdsm_cmd_desc(pdsm);
/* Validate pdsm descriptor */
/* Ensure that reserved fields are 0 */
if (pdsm_pkg->reserved[0] || pdsm_pkg->reserved[1]) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Invalid reserved field\n",
pdsm);
return -EINVAL;
}
/* If pdsm expects some input, then ensure that the size_in matches */
if (pdsc->size_in &&
pkg->nd_size_in != (pdsc->size_in + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_in=%d\n",
pdsm, pkg->nd_size_in);
return -EINVAL;
}
/* If pdsm wants to return data, then ensure that size_out matches */
if (pdsc->size_out &&
pkg->nd_size_out != (pdsc->size_out + ND_PDSM_HDR_SIZE)) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Mismatched size_out=%d\n",
pdsm, pkg->nd_size_out);
return -EINVAL;
}
/* Service the pdsm */
if (pdsc->service) {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Servicing..\n", pdsm);
rc = pdsc->service(p, &pdsm_pkg->payload);
if (rc < 0) {
/* error encountered while servicing pdsm */
pdsm_pkg->cmd_status = rc;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
} else {
/* pdsm serviced and 'rc' bytes written to payload */
pdsm_pkg->cmd_status = 0;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE + rc;
}
} else {
dev_dbg(&p->pdev->dev, "PDSM[0x%x]: Unsupported PDSM request\n",
pdsm);
pdsm_pkg->cmd_status = -ENOENT;
pkg->nd_fw_size = ND_PDSM_HDR_SIZE;
}
return pdsm_pkg->cmd_status;
}
static 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)
{
struct nd_cmd_get_config_size *get_size_hdr;
struct nd_cmd_pkg *call_pkg = NULL;
struct papr_scm_priv *p;
int rc;
rc = is_cmd_valid(nvdimm, cmd, buf, buf_len);
if (rc) {
pr_debug("Invalid cmd=0x%x. Err=%d\n", cmd, rc);
return rc;
}
/* Use a local variable in case cmd_rc pointer is NULL */
if (!cmd_rc)
cmd_rc = &rc;
p = nvdimm_provider_data(nvdimm);
switch (cmd) {
case ND_CMD_GET_CONFIG_SIZE:
get_size_hdr = buf;
get_size_hdr->status = 0;
get_size_hdr->max_xfer = 8;
get_size_hdr->config_size = p->metadata_size;
*cmd_rc = 0;
break;
case ND_CMD_GET_CONFIG_DATA:
*cmd_rc = papr_scm_meta_get(p, buf);
break;
case ND_CMD_SET_CONFIG_DATA:
*cmd_rc = papr_scm_meta_set(p, buf);
break;
case ND_CMD_CALL:
call_pkg = (struct nd_cmd_pkg *)buf;
*cmd_rc = papr_scm_service_pdsm(p, call_pkg);
break;
default:
dev_dbg(&p->pdev->dev, "Unknown command = %d\n", cmd);
return -EINVAL;
}
dev_dbg(&p->pdev->dev, "returned with cmd_rc = %d\n", *cmd_rc);
return 0;
}
static ssize_t health_bitmap_inject_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);
return sprintf(buf, "%#llx\n",
READ_ONCE(p->health_bitmap_inject_mask));
}
static DEVICE_ATTR_ADMIN_RO(health_bitmap_inject);
static ssize_t perf_stats_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int index;
ssize_t rc;
struct seq_buf s;
struct papr_scm_perf_stat *stat;
struct papr_scm_perf_stats *stats;
struct nvdimm *dimm = to_nvdimm(dev);
struct papr_scm_priv *p = nvdimm_provider_data(dimm);
if (!p->stat_buffer_len)
return -ENOENT;
/* Allocate the buffer for phyp where stats are written */
stats = kzalloc(p->stat_buffer_len, GFP_KERNEL);
if (!stats)
return -ENOMEM;
/* Ask phyp to return all dimm perf stats */
rc = drc_pmem_query_stats(p, stats, 0);
if (rc)
goto free_stats;
/*
* Go through the returned output buffer and print stats and
* values. Since stat_id is essentially a char string of
* 8 bytes, simply use the string format specifier to print it.
*/
seq_buf_init(&s, buf, PAGE_SIZE);
for (index = 0, stat = stats->scm_statistic;
index < be32_to_cpu(stats->num_statistics);
++index, ++stat) {
seq_buf_printf(&s, "%.8s = 0x%016llX\n",
stat->stat_id,
be64_to_cpu(stat->stat_val));
}
free_stats:
kfree(stats);
return rc ? rc : (ssize_t)seq_buf_used(&s);
}
static DEVICE_ATTR_ADMIN_RO(perf_stats);
static ssize_t 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);
struct seq_buf s;
u64 health;
int rc;
rc = drc_pmem_query_health(p);
if (rc)
return rc;
/* Copy health_bitmap locally, check masks & update out buffer */
health = READ_ONCE(p->health_bitmap);
seq_buf_init(&s, buf, PAGE_SIZE);
if (health & PAPR_PMEM_UNARMED_MASK)
seq_buf_printf(&s, "not_armed ");
if (health & PAPR_PMEM_BAD_SHUTDOWN_MASK)
seq_buf_printf(&s, "flush_fail ");
if (health & PAPR_PMEM_BAD_RESTORE_MASK)
seq_buf_printf(&s, "restore_fail ");
if (health & PAPR_PMEM_ENCRYPTED)
seq_buf_printf(&s, "encrypted ");
if (health & PAPR_PMEM_SMART_EVENT_MASK)
seq_buf_printf(&s, "smart_notify ");
if (health & PAPR_PMEM_SCRUBBED_AND_LOCKED)
seq_buf_printf(&s, "scrubbed locked ");
if (seq_buf_used(&s))
seq_buf_printf(&s, "\n");
return seq_buf_used(&s);
}
DEVICE_ATTR_RO(flags);
static ssize_t dirty_shutdown_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);
return sysfs_emit(buf, "%llu\n", p->dirty_shutdown_counter);
}
DEVICE_ATTR_RO(dirty_shutdown);
static umode_t papr_nd_attribute_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct nvdimm *nvdimm = to_nvdimm(dev);
struct papr_scm_priv *p = nvdimm_provider_data(nvdimm);
/* For if perf-stats not available remove perf_stats sysfs */
if (attr == &dev_attr_perf_stats.attr && p->stat_buffer_len == 0)
return 0;
return attr->mode;
}
/* papr_scm specific dimm attributes */
static struct attribute *papr_nd_attributes[] = {
&dev_attr_flags.attr,
&dev_attr_perf_stats.attr,
&dev_attr_dirty_shutdown.attr,
&dev_attr_health_bitmap_inject.attr,
NULL,
};
static const struct attribute_group papr_nd_attribute_group = {
.name = "papr",
.is_visible = papr_nd_attribute_visible,
.attrs = papr_nd_attributes,
};
static const struct attribute_group *papr_nd_attr_groups[] = {
&papr_nd_attribute_group,
NULL,
};
static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
{
struct device *dev = &p->pdev->dev;
struct nd_mapping_desc mapping;
struct nd_region_desc ndr_desc;
unsigned long dimm_flags;
int target_nid, online_nid;
p->bus_desc.ndctl = papr_scm_ndctl;
p->bus_desc.module = THIS_MODULE;
p->bus_desc.of_node = p->pdev->dev.of_node;
p->bus_desc.provider_name = kstrdup(p->pdev->name, GFP_KERNEL);
/* Set the dimm command family mask to accept PDSMs */
set_bit(NVDIMM_FAMILY_PAPR, &p->bus_desc.dimm_family_mask);
if (!p->bus_desc.provider_name)
return -ENOMEM;
p->bus = nvdimm_bus_register(NULL, &p->bus_desc);
if (!p->bus) {
dev_err(dev, "Error creating nvdimm bus %pOF\n", p->dn);
kfree(p->bus_desc.provider_name);
return -ENXIO;
}
dimm_flags = 0;
set_bit(NDD_LABELING, &dimm_flags);
/*
* Check if the nvdimm is unarmed. No locking needed as we are still
* initializing. Ignore error encountered if any.
*/
__drc_pmem_query_health(p);
if (p->health_bitmap & PAPR_PMEM_UNARMED_MASK)
set_bit(NDD_UNARMED, &dimm_flags);
p->nvdimm = nvdimm_create(p->bus, p, papr_nd_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;
}
if (nvdimm_bus_check_dimm_count(p->bus, 1))
goto err;
/* now add the region */
memset(&mapping, 0, sizeof(mapping));
mapping.nvdimm = p->nvdimm;
mapping.start = 0;
mapping.size = p->blocks * p->block_size; // XXX: potential overflow?
memset(&ndr_desc, 0, sizeof(ndr_desc));
target_nid = dev_to_node(&p->pdev->dev);
online_nid = numa_map_to_online_node(target_nid);
ndr_desc.numa_node = online_nid;
ndr_desc.target_node = target_nid;
ndr_desc.res = &p->res;
ndr_desc.of_node = p->dn;
ndr_desc.provider_data = p;
ndr_desc.mapping = &mapping;
ndr_desc.num_mappings = 1;
ndr_desc.nd_set = &p->nd_set;
if (p->hcall_flush_required) {
set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
ndr_desc.flush = papr_scm_pmem_flush;
}
if (p->is_volatile)
p->region = nvdimm_volatile_region_create(p->bus, &ndr_desc);
else {
set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
p->region = nvdimm_pmem_region_create(p->bus, &ndr_desc);
}
if (!p->region) {
dev_err(dev, "Error registering region %pR from %pOF\n",
ndr_desc.res, p->dn);
goto err;
}
if (target_nid != online_nid)
dev_info(dev, "Region registered with target node %d and online node %d",
target_nid, online_nid);
mutex_lock(&papr_ndr_lock);
list_add_tail(&p->region_list, &papr_nd_regions);
mutex_unlock(&papr_ndr_lock);
return 0;
err: nvdimm_bus_unregister(p->bus);
kfree(p->bus_desc.provider_name);
return -ENXIO;
}
static void papr_scm_add_badblock(struct nd_region *region,
struct nvdimm_bus *bus, u64 phys_addr)
{
u64 aligned_addr = ALIGN_DOWN(phys_addr, L1_CACHE_BYTES);
if (nvdimm_bus_add_badrange(bus, aligned_addr, L1_CACHE_BYTES)) {
pr_err("Bad block registration for 0x%llx failed\n", phys_addr);
return;
}
pr_debug("Add memory range (0x%llx - 0x%llx) as bad range\n",
aligned_addr, aligned_addr + L1_CACHE_BYTES);
nvdimm_region_notify(region, NVDIMM_REVALIDATE_POISON);
}
static int handle_mce_ue(struct notifier_block *nb, unsigned long val,
void *data)
{
struct machine_check_event *evt = data;
struct papr_scm_priv *p;
u64 phys_addr;
bool found = false;
if (evt->error_type != MCE_ERROR_TYPE_UE)
return NOTIFY_DONE;
if (list_empty(&papr_nd_regions))
return NOTIFY_DONE;
/*
* The physical address obtained here is PAGE_SIZE aligned, so get the
* exact address from the effective address
*/
phys_addr = evt->u.ue_error.physical_address +
(evt->u.ue_error.effective_address & ~PAGE_MASK);
if (!evt->u.ue_error.physical_address_provided ||
!is_zone_device_page(pfn_to_page(phys_addr >> PAGE_SHIFT)))
return NOTIFY_DONE;
/* mce notifier is called from a process context, so mutex is safe */
mutex_lock(&papr_ndr_lock);
list_for_each_entry(p, &papr_nd_regions, region_list) {
if (phys_addr >= p->res.start && phys_addr <= p->res.end) {
found = true;
break;
}
}
if (found)
papr_scm_add_badblock(p->region, p->bus, phys_addr);
mutex_unlock(&papr_ndr_lock);
return found ? NOTIFY_OK : NOTIFY_DONE;
}
static struct notifier_block mce_ue_nb = {
.notifier_call = handle_mce_ue
};
static int papr_scm_probe(struct platform_device *pdev)
{
struct device_node *dn = pdev->dev.of_node;
u32 drc_index, metadata_size;
u64 blocks, block_size;
struct papr_scm_priv *p;
u8 uuid_raw[UUID_SIZE];
const char *uuid_str;
ssize_t stat_size;
uuid_t uuid;
int rc;
/* check we have all the required DT properties */
if (of_property_read_u32(dn, "ibm,my-drc-index", &drc_index)) {
dev_err(&pdev->dev, "%pOF: missing drc-index!\n", dn);
return -ENODEV;
}
if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
return -ENODEV;
}
if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
return -ENODEV;
}
if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
return -ENODEV;
}
/*
* open firmware platform device create won't update the NUMA
* distance table. For PAPR SCM devices we use numa_map_to_online_node()
* to find the nearest online NUMA node and that requires correct
* distance table information.
*/
update_numa_distance(dn);
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
/* Initialize the dimm mutex */
mutex_init(&p->health_mutex);
/* optional DT properties */
of_property_read_u32(dn, "ibm,metadata-size", &metadata_size);
p->dn = dn;
p->drc_index = drc_index;
p->block_size = block_size;
p->blocks = blocks;
p->is_volatile = !of_property_read_bool(dn, "ibm,cache-flush-required");
p->hcall_flush_required = of_property_read_bool(dn, "ibm,hcall-flush-required");
if (of_property_read_u64(dn, "ibm,persistence-failed-count",
&p->dirty_shutdown_counter))
p->dirty_shutdown_counter = 0;
/* We just need to ensure that set cookies are unique across */
uuid_parse(uuid_str, &uuid);
/*
* The cookie1 and cookie2 are not really little endian.
* We store a raw buffer representation of the
* uuid string so that we can compare this with the label
* area cookie irrespective of the endian configuration
* with which the kernel is built.
*
* Historically we stored the cookie in the below format.
* for a uuid string 72511b67-0b3b-42fd-8d1d-5be3cae8bcaa
* cookie1 was 0xfd423b0b671b5172
* cookie2 was 0xaabce8cae35b1d8d
*/
export_uuid(uuid_raw, &uuid);
p->nd_set.cookie1 = get_unaligned_le64(&uuid_raw[0]);
p->nd_set.cookie2 = get_unaligned_le64(&uuid_raw[8]);
/* might be zero */
p->metadata_size = metadata_size;
p->pdev = pdev;
/* request the hypervisor to bind this region to somewhere in memory */
rc = drc_pmem_bind(p);
/* If phyp says drc memory still bound then force unbound and retry */
if (rc == H_OVERLAP)
rc = drc_pmem_query_n_bind(p);
if (rc != H_SUCCESS) {
dev_err(&p->pdev->dev, "bind err: %d\n", rc);
rc = -ENXIO;
goto err;
}
/* setup the resource for the newly bound range */
p->res.start = p->bound_addr;
p->res.end = p->bound_addr + p->blocks * p->block_size - 1;
p->res.name = pdev->name;
p->res.flags = IORESOURCE_MEM;
/* Try retrieving the stat buffer and see if its supported */
stat_size = drc_pmem_query_stats(p, NULL, 0);
if (stat_size > 0) {
p->stat_buffer_len = stat_size;
dev_dbg(&p->pdev->dev, "Max perf-stat size %lu-bytes\n",
p->stat_buffer_len);
}
rc = papr_scm_nvdimm_init(p);
if (rc)
goto err2;
platform_set_drvdata(pdev, p);
papr_scm_pmu_register(p);
return 0;
err2: drc_pmem_unbind(p);
err: kfree(p);
return rc;
}
static void papr_scm_remove(struct platform_device *pdev)
{
struct papr_scm_priv *p = platform_get_drvdata(pdev);
mutex_lock(&papr_ndr_lock);
list_del(&p->region_list);
mutex_unlock(&papr_ndr_lock);
nvdimm_bus_unregister(p->bus);
drc_pmem_unbind(p);
if (pdev->archdata.priv)
unregister_nvdimm_pmu(pdev->archdata.priv);
pdev->archdata.priv = NULL;
kfree(p->bus_desc.provider_name);
kfree(p);
}
static const struct of_device_id papr_scm_match[] = {
{ .compatible = "ibm,pmemory" },
{ .compatible = "ibm,pmemory-v2" },
{ },
};
static struct platform_driver papr_scm_driver = {
.probe = papr_scm_probe,
.remove_new = papr_scm_remove,
.driver = {
.name = "papr_scm",
.of_match_table = papr_scm_match,
},
};
static int __init papr_scm_init(void)
{
int ret;
ret = platform_driver_register(&papr_scm_driver);
if (!ret)
mce_register_notifier(&mce_ue_nb);
return ret;
}
module_init(papr_scm_init);
static void __exit papr_scm_exit(void)
{
mce_unregister_notifier(&mce_ue_nb);
platform_driver_unregister(&papr_scm_driver);
}
module_exit(papr_scm_exit);
MODULE_DEVICE_TABLE(of, papr_scm_match);
MODULE_DESCRIPTION("PAPR Storage Class Memory interface driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("IBM Corporation");
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