OSCL-LXR linux-6.0.1/​arch/​powerpc/​platforms/​pseries/​papr_scm.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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 <asm/papr_pdsm.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))
 
 /* DIMM health bitmap indicators */
 /* SCM device is unable to persist memory contents */
 #define PAPR_PMEM_UNARMED                   (1ULL << (63 - 0))
 /* SCM device failed to persist memory contents */
 #define PAPR_PMEM_SHUTDOWN_DIRTY            (1ULL << (63 - 1))
 /* SCM device contents are persisted from previous IPL */
 #define PAPR_PMEM_SHUTDOWN_CLEAN            (1ULL << (63 - 2))
 /* SCM device contents are not persisted from previous IPL */
 #define PAPR_PMEM_EMPTY                     (1ULL << (63 - 3))
 /* SCM device memory life remaining is critically low */
 #define PAPR_PMEM_HEALTH_CRITICAL           (1ULL << (63 - 4))
 /* SCM device will be garded off next IPL due to failure */
 #define PAPR_PMEM_HEALTH_FATAL              (1ULL << (63 - 5))
 /* SCM contents cannot persist due to current platform health status */
 #define PAPR_PMEM_HEALTH_UNHEALTHY          (1ULL << (63 - 6))
 /* SCM device is unable to persist memory contents in certain conditions */
 #define PAPR_PMEM_HEALTH_NON_CRITICAL       (1ULL << (63 - 7))
 /* SCM device is encrypted */
 #define PAPR_PMEM_ENCRYPTED                 (1ULL << (63 - 8))
 /* SCM device has been scrubbed and locked */
 #define PAPR_PMEM_SCRUBBED_AND_LOCKED       (1ULL << (63 - 9))
 
 /* Bits status indicators for health bitmap indicating unarmed dimm */
 #define PAPR_PMEM_UNARMED_MASK (PAPR_PMEM_UNARMED |     \
                 PAPR_PMEM_HEALTH_UNHEALTHY)
 
 /* Bits status indicators for health bitmap indicating unflushed dimm */
 #define PAPR_PMEM_BAD_SHUTDOWN_MASK (PAPR_PMEM_SHUTDOWN_DIRTY)
 
 /* Bits status indicators for health bitmap indicating unrestored dimm */
 #define PAPR_PMEM_BAD_RESTORE_MASK  (PAPR_PMEM_EMPTY)
 
 /* Bit status indicators for smart event notification */
 #define PAPR_PMEM_SMART_EVENT_MASK (PAPR_PMEM_HEALTH_CRITICAL | \
                     PAPR_PMEM_HEALTH_FATAL |    \
                     PAPR_PMEM_HEALTH_UNHEALTHY)
 
 #define PAPR_SCM_PERF_STATS_EYECATCHER __stringify(SCMSTATS)
 #define PAPR_SCM_PERF_STATS_VERSION 0x1
 
 /* 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;
     }
 
 
     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 int 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);
 
     return 0;
 }
 
 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 = 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_LICENSE("GPL");
 MODULE_AUTHOR("IBM Corporation");

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