diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries')
| -rw-r--r-- | arch/powerpc/platforms/pseries/papr_scm.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index 3d1235a76ba9..f37f3f70007d 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -64,6 +64,26 @@ 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; @@ -92,6 +112,9 @@ struct papr_scm_priv { /* Health information for the dimm */ u64 health_bitmap; + + /* length of the stat buffer as expected by phyp */ + size_t stat_buffer_len; }; static LIST_HEAD(papr_nd_regions); @@ -201,6 +224,79 @@ err_out: } /* + * 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 byes 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_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; +} + +/* * Issue hcall to retrieve dimm health info and populate papr_scm_priv with the * health information. */ @@ -637,6 +733,48 @@ static int papr_scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, return 0; } +static ssize_t perf_stats_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int index, 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 : seq_buf_used(&s); +} +DEVICE_ATTR_RO(perf_stats); + static ssize_t flags_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -682,6 +820,7 @@ DEVICE_ATTR_RO(flags); /* papr_scm specific dimm attributes */ static struct attribute *papr_nd_attributes[] = { &dev_attr_flags.attr, + &dev_attr_perf_stats.attr, NULL, }; @@ -702,6 +841,7 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p) struct nd_region_desc ndr_desc; unsigned long dimm_flags; int target_nid, online_nid; + ssize_t stat_size; p->bus_desc.ndctl = papr_scm_ndctl; p->bus_desc.module = THIS_MODULE; @@ -769,6 +909,16 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p) list_add_tail(&p->region_list, &papr_nd_regions); mutex_unlock(&papr_ndr_lock); + /* Try retriving 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); + } else { + dev_info(&p->pdev->dev, "Dimm performance stats unavailable\n"); + } + return 0; err: nvdimm_bus_unregister(p->bus); |