| Message ID | 20200731064153.182203-2-vaibhav@linux.ibm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 2d02bf835e5731de632c8a13567905fa7c0da01c |
| Headers | show |
| Series | powerpc/papr_scm: add support for reporting NVDIMM 'life_used_percentage' metric | expand |
Vaibhav Jain <vaibhav@linux.ibm.com> writes: > Update papr_scm.c to query dimm performance statistics from PHYP via > H_SCM_PERFORMANCE_STATS hcall and export them to user-space as PAPR > specific NVDIMM attribute 'perf_stats' in sysfs. The patch also > provide a sysfs ABI documentation for the stats being reported and > their meanings. > > During NVDIMM probe time in papr_scm_nvdimm_init() a special variant > of H_SCM_PERFORMANCE_STATS hcall is issued to check if collection of > performance statistics is supported or not. If successful then a PHYP > returns a maximum possible buffer length needed to read all > performance stats. This returned value is stored in a per-nvdimm > attribute 'stat_buffer_len'. > > The layout of request buffer for reading NVDIMM performance stats from > PHYP is defined in 'struct papr_scm_perf_stats' and 'struct > papr_scm_perf_stat'. These structs are used in newly introduced > drc_pmem_query_stats() that issues the H_SCM_PERFORMANCE_STATS hcall. > > The sysfs access function perf_stats_show() uses value > 'stat_buffer_len' to allocate a buffer large enough to hold all > possible NVDIMM performance stats and passes it to > drc_pmem_query_stats() to populate. Finally statistics reported in the > buffer are formatted into the sysfs access function output buffer. > > Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> > --- > Changelog: > > v4: > * Fixed a build issue with this patch by moving a hunk from second > patch in series to this patch. [ Aneesh ] > > v3: > * Updated drc_pmem_query_stats() to not require 'buff_size' and 'out' > args to the function. Instead 'buff_size' is calculated from > 'num_stats' and instead of populating 'R4' in arg 'out' the value is > returned from the function in case 'R4' represents > 'max-buffer-size'. > > Resend: > None > > v2: > * Updated 'struct papr_scm_perf_stats' and 'struct papr_scm_perf_stat' > to use big-endian types. [ Aneesh ] > * s/len_stat_buffer/stat_buffer_len/ [ Aneesh ] > * s/statistics_id/stat_id/ , s/statistics_val/stat_val/ [ Aneesh ] > * Conversion from Big endian to cpu endian happens later rather than > just after its fetched from PHYP. > * Changed a log statement to unambiguously report dimm performance > stats are not available for the given nvdimm [ Ira ] > * Restructed some code to handle error case first [ Ira ] > --- > Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 ++++ > arch/powerpc/platforms/pseries/papr_scm.c | 150 ++++++++++++++++++ > 2 files changed, 177 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem > index 5b10d036a8d4..c1a67275c43f 100644 > --- a/Documentation/ABI/testing/sysfs-bus-papr-pmem > +++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem > @@ -25,3 +25,30 @@ Description: > NVDIMM have been scrubbed. > * "locked" : Indicating that NVDIMM contents cant > be modified until next power cycle. > + > +What: /sys/bus/nd/devices/nmemX/papr/perf_stats > +Date: May, 2020 > +KernelVersion: v5.9 > +Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-nvdimm@lists.01.org, > +Description: > + (RO) Report various performance stats related to papr-scm NVDIMM > + device. Each stat is reported on a new line with each line > + composed of a stat-identifier followed by it value. Below are > + currently known dimm performance stats which are reported: > + > + * "CtlResCt" : Controller Reset Count > + * "CtlResTm" : Controller Reset Elapsed Time > + * "PonSecs " : Power-on Seconds > + * "MemLife " : Life Remaining > + * "CritRscU" : Critical Resource Utilization > + * "HostLCnt" : Host Load Count > + * "HostSCnt" : Host Store Count > + * "HostSDur" : Host Store Duration > + * "HostLDur" : Host Load Duration > + * "MedRCnt " : Media Read Count > + * "MedWCnt " : Media Write Count > + * "MedRDur " : Media Read Duration > + * "MedWDur " : Media Write Duration > + * "CchRHCnt" : Cache Read Hit Count > + * "CchWHCnt" : Cache Write Hit Count > + * "FastWCnt" : Fast Write Count > \ No newline at end of file > 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); > @@ -200,6 +223,79 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *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 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; So we end up making a HCALL for each read of the sysfs file? You do throttle that for PAPR_HEALTH hcall (flags sysfs file). Do we need to do that here? If not should we make this CAP_SYS_ADMIN? You can possibly add is_visible callback to papr group and then restrict this all to CAP_SYS_ADMIN? > + /* > + * 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); > -- > 2.26.2
diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem index 5b10d036a8d4..c1a67275c43f 100644 --- a/Documentation/ABI/testing/sysfs-bus-papr-pmem +++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem @@ -25,3 +25,30 @@ Description: NVDIMM have been scrubbed. * "locked" : Indicating that NVDIMM contents cant be modified until next power cycle. + +What: /sys/bus/nd/devices/nmemX/papr/perf_stats +Date: May, 2020 +KernelVersion: v5.9 +Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-nvdimm@lists.01.org, +Description: + (RO) Report various performance stats related to papr-scm NVDIMM + device. Each stat is reported on a new line with each line + composed of a stat-identifier followed by it value. Below are + currently known dimm performance stats which are reported: + + * "CtlResCt" : Controller Reset Count + * "CtlResTm" : Controller Reset Elapsed Time + * "PonSecs " : Power-on Seconds + * "MemLife " : Life Remaining + * "CritRscU" : Critical Resource Utilization + * "HostLCnt" : Host Load Count + * "HostSCnt" : Host Store Count + * "HostSDur" : Host Store Duration + * "HostLDur" : Host Load Duration + * "MedRCnt " : Media Read Count + * "MedWCnt " : Media Write Count + * "MedRDur " : Media Read Duration + * "MedWDur " : Media Write Duration + * "CchRHCnt" : Cache Read Hit Count + * "CchWHCnt" : Cache Write Hit Count + * "FastWCnt" : Fast Write Count \ No newline at end of file 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); @@ -200,6 +223,79 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *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 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);
Update papr_scm.c to query dimm performance statistics from PHYP via H_SCM_PERFORMANCE_STATS hcall and export them to user-space as PAPR specific NVDIMM attribute 'perf_stats' in sysfs. The patch also provide a sysfs ABI documentation for the stats being reported and their meanings. During NVDIMM probe time in papr_scm_nvdimm_init() a special variant of H_SCM_PERFORMANCE_STATS hcall is issued to check if collection of performance statistics is supported or not. If successful then a PHYP returns a maximum possible buffer length needed to read all performance stats. This returned value is stored in a per-nvdimm attribute 'stat_buffer_len'. The layout of request buffer for reading NVDIMM performance stats from PHYP is defined in 'struct papr_scm_perf_stats' and 'struct papr_scm_perf_stat'. These structs are used in newly introduced drc_pmem_query_stats() that issues the H_SCM_PERFORMANCE_STATS hcall. The sysfs access function perf_stats_show() uses value 'stat_buffer_len' to allocate a buffer large enough to hold all possible NVDIMM performance stats and passes it to drc_pmem_query_stats() to populate. Finally statistics reported in the buffer are formatted into the sysfs access function output buffer. Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> --- Changelog: v4: * Fixed a build issue with this patch by moving a hunk from second patch in series to this patch. [ Aneesh ] v3: * Updated drc_pmem_query_stats() to not require 'buff_size' and 'out' args to the function. Instead 'buff_size' is calculated from 'num_stats' and instead of populating 'R4' in arg 'out' the value is returned from the function in case 'R4' represents 'max-buffer-size'. Resend: None v2: * Updated 'struct papr_scm_perf_stats' and 'struct papr_scm_perf_stat' to use big-endian types. [ Aneesh ] * s/len_stat_buffer/stat_buffer_len/ [ Aneesh ] * s/statistics_id/stat_id/ , s/statistics_val/stat_val/ [ Aneesh ] * Conversion from Big endian to cpu endian happens later rather than just after its fetched from PHYP. * Changed a log statement to unambiguously report dimm performance stats are not available for the given nvdimm [ Ira ] * Restructed some code to handle error case first [ Ira ] --- Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 ++++ arch/powerpc/platforms/pseries/papr_scm.c | 150 ++++++++++++++++++ 2 files changed, 177 insertions(+)