// SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) "papr-scm: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 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; /* array to have event_code and stat_id mappings */ char **nvdimm_events_map; }; 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 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 = (struct papr_scm_priv *)dev->driver_data; int rc, size; /* Allocate request buffer enough to hold single performance stat */ size = sizeof(struct papr_scm_perf_stats) + sizeof(struct papr_scm_perf_stat); if (!p || !p->nvdimm_events_map) return -EINVAL; stats = kzalloc(size, GFP_KERNEL); if (!stats) return -ENOMEM; stat = &stats->scm_statistic[0]; memcpy(&stat->stat_id, p->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 int papr_scm_pmu_check_events(struct papr_scm_priv *p, struct nvdimm_pmu *nd_pmu) { struct papr_scm_perf_stat *stat; struct papr_scm_perf_stats *stats; int index, rc, count; u32 available_events; if (!p->stat_buffer_len) return -ENOENT; available_events = (p->stat_buffer_len - sizeof(struct papr_scm_perf_stats)) / sizeof(struct papr_scm_perf_stat); /* Allocate the buffer for phyp where stats are written */ stats = kzalloc(p->stat_buffer_len, GFP_KERNEL); if (!stats) { rc = -ENOMEM; return rc; } /* Allocate memory to nvdimm_event_map */ p->nvdimm_events_map = kcalloc(available_events, sizeof(char *), GFP_KERNEL); if (!p->nvdimm_events_map) { rc = -ENOMEM; goto out_stats; } /* Called to get list of events supported */ rc = drc_pmem_query_stats(p, stats, 0); if (rc) goto out_nvdimm_events_map; for (index = 0, stat = stats->scm_statistic, count = 0; index < available_events; index++, ++stat) { p->nvdimm_events_map[count] = kmemdup_nul(stat->stat_id, 8, GFP_KERNEL); if (!p->nvdimm_events_map[count]) { rc = -ENOMEM; goto out_nvdimm_events_map; } count++; } p->nvdimm_events_map[count] = NULL; kfree(stats); return 0; out_nvdimm_events_map: kfree(p->nvdimm_events_map); out_stats: kfree(stats); return rc; } 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; } rc = papr_scm_pmu_check_events(p, nd_pmu); if (rc) 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_register_err; /* * Set archdata.priv value to nvdimm_pmu structure, to handle the * unregistering of pmu device. */ p->pdev->archdata.priv = nd_pmu; return; pmu_register_err: kfree(p->nvdimm_events_map); 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->nvdimm_events_map); 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");