[ndctl RFC-PATCH 2/4] papr_scm: Add support for fetching dimm-stats

Add support for fetching dimm-stats from 'papr_scm' module by implementing newly introduced dimm-op 'new_stats' as papr_new_stats(). The function uses two pdsm to fetch dimm-stats. * PAPR_SCM_PDSM_FETCH_PERF_STATS: Asks 'papr_scm' module to request fresh values of all dimm-stats from PHYP and store then in its perf-stats buffer. It returns the size of the perf-stats buffer as bytes in command package 'struct nd_pdsm_fetch_perf_stats'. * PAPR_SCM_PDSM_READ_PERF_STATS: Once dimm-stats are placed in 'papr_scm' perf-stats buffer, this pdsm is issued to read it contents and copy then to libndctl user-space memory using 'struct nd_pdsm_read_perf_stats' payload. Since libnvdimm enforces a envelope size limit of 256 bytes, this pdsm uses libndctl command iterator functionality to incrementally copy the entire perf-stat buffer content from 'papr_scm' module. The patch introduces new members in 'struct dimm_priv' to hold the dimm-stat information fetched from 'papr_scm' module. A new function update_perf_stat_size() is introduced that handles response to pdsm FETCH_PERF_STATS and allocate enough memory to 'dimm_priv.perf_stats' to hold all dimm-stats. When papr_new_stats() is called by libndctl in response to '--stats' arg being given to ndctl-list command, following sequence is executed: 1. Allocate and submit ndctl_cmd to issue pdsm FETCH_PERF_STATS. 2. On success call update_dimm_stats() that in return calls update_perf_stat_size() to allocate buffer 'dimm_priv.perf_stats' needed to store dimm-stats. 3. Allocate ndctl_cmd to issue pdsm READ_PERF_STATS. 4. Setup the command iterator pointing to dimm_priv.perf_stats to hold the entire data and setting the total length of the read operation. 5. Setup the various get/set callback functions for command 'xfer' and 'offset' access. 6. Return this command back to libndctl that will then submit the command to libnvdimm. Signed-off-by: Vaibhav Jain <vaibhav(a)linux.ibm.com&gt; --- ndctl/lib/papr_scm.c | 169 ++++++++++++++++++++++++++++++++++++++ ndctl/lib/papr_scm_pdsm.h | 48 +++++++++++ 2 files changed, 217 insertions(+) diff --git a/ndctl/lib/papr_scm.c b/ndctl/lib/papr_scm.c index 562262111c91..14fb6d48c12a 100644 --- a/ndctl/lib/papr_scm.c +++ b/ndctl/lib/papr_scm.c @@ -14,6 +14,7 @@ #include <stdlib.h> #include <limits.h> #include <util/log.h> +#include <util/util.h> #include <ndctl.h> #include <ndctl/libndctl.h> #include <lib/private.h> @@ -40,11 +41,19 @@ #define CMD_PKG_SUBMITTED 1 #define CMD_PKG_PARSED 2 +/* Number of bytes to transffer in each ioctl for pdsm READ_PERF_STATS */ +#define GET_PERF_STAT_XFER_SIZE 16 + /* Per dimm data. Holds per-dimm data parsed from the cmd_pkgs */ struct dimm_priv { /* Cache the dimm health status */ struct nd_papr_pdsm_health health; + + /* Cache the dimm perf-stats buffer, length in bytes, count */ + ssize_t len_perf_stats; + ssize_t count_perf_stats; + struct nd_pdsm_perf_stat *perf_stats; }; static bool papr_cmd_is_supported(struct ndctl_dimm *dimm, int cmd) @@ -136,6 +145,45 @@ static int update_dimm_health(struct ndctl_dimm *dimm, struct ndctl_cmd *cmd) return -EINVAL; } +/* Parse the PAPR_SCM_PDSM_FETCH_PERF_STATS command package */ +static int update_perf_stat_size(struct ndctl_dimm *dimm, struct ndctl_cmd *cmd) +{ + struct nd_pdsm_cmd_pkg *pcmd = nd_to_pdsm_cmd_pkg(cmd->pkg); + struct dimm_priv *p = dimm->dimm_user_data; + const struct nd_pdsm_fetch_perf_stats * psize = + pdsm_cmd_to_payload(pcmd); + + /* is it an unknown version */ + if (pcmd->payload_version != 1) { + papr_err(dimm, "Unknown payload version for perf stat size\n"); + return -EBADE; + } + + /* Update the perf_size and reallocate the buffer if needed */ + if (p->len_perf_stats < psize->max_stats_size) { + struct nd_pdsm_perf_stat *new_stats, *old_stats; + old_stats = p->perf_stats; + + new_stats = (struct nd_pdsm_perf_stat *) + calloc(1, psize->max_stats_size); + if (!new_stats) { + papr_err(dimm, "Unable to allocate new perf_stats buffer\n"); + return -ENOMEM; + } + if (old_stats) { + /* Copy the old buffer contents to new */ + memcpy(new_stats, old_stats, p->len_perf_stats); + free(old_stats); + } + p->perf_stats = new_stats; + } + + p->len_perf_stats = psize->max_stats_size; + papr_dbg(dimm, "dimm perf stats size =%lu\n", + p->len_perf_stats); + return 0; +} + /* Parse a command payload and update dimm flags/private data */ static int update_dimm_stats(struct ndctl_dimm *dimm, struct ndctl_cmd *cmd) { @@ -163,6 +211,8 @@ static int update_dimm_stats(struct ndctl_dimm *dimm, struct ndctl_cmd *cmd) switch (pcmd_to_pdsm(pcmd)) { case PAPR_SCM_PDSM_HEALTH: return update_dimm_health(dimm, cmd); + case PAPR_SCM_PDSM_FETCH_PERF_STATS: + return update_perf_stat_size(dimm, cmd); default: papr_err(dimm, "Unhandled pdsm-request 0x%016llx\n", pcmd_to_pdsm(pcmd)); @@ -286,10 +336,128 @@ static void papr_dimm_uninit(struct ndctl_dimm *dimm) return; } + if (p->perf_stats) + free(p->perf_stats); + dimm->dimm_user_data = NULL; free(p); } +/* + * Check if the given command is of type PDSM_READ_PERF_STATS and return + * 'struct nd_pdsm_read_perf_stats *' otherwise return NULL. + */ +static struct nd_pdsm_read_perf_stats *cmd_to_read_perf(struct ndctl_cmd *cmd) +{ + struct nd_pdsm_cmd_pkg *pcmd = nd_to_pdsm_cmd_pkg(cmd->pkg); + + if (cmd && cmd_is_valid(cmd->dimm, cmd) && + pcmd_to_pdsm(pcmd) == PAPR_SCM_PDSM_READ_PERF_STATS) + return (struct nd_pdsm_read_perf_stats *) + (pdsm_cmd_to_payload(pcmd)); + else + return NULL; +} + +/* Callbacks from libndctl core to handle iterable read_perf_stats command */ +static u32 papr_get_xfer(struct ndctl_cmd *cmd) +{ + struct nd_pdsm_read_perf_stats *stats = cmd_to_read_perf(cmd); + if (stats == NULL) + papr_err(cmd->dimm, "Invalid command\n"); + return stats ? stats->in_length : 0; +} + +static u32 papr_get_offset(struct ndctl_cmd *cmd) +{ + struct nd_pdsm_read_perf_stats *stats = cmd_to_read_perf(cmd); + if (stats == NULL) + papr_err(cmd->dimm, "Invalid command\n"); + return stats ? stats->in_offset : 0; +} + +static void papr_set_xfer(struct ndctl_cmd *cmd, u32 xfer) +{ + struct nd_pdsm_read_perf_stats *stats = cmd_to_read_perf(cmd); + if (stats == NULL) + papr_err(cmd->dimm, "Invalid command\n"); + stats->in_length = xfer; +} + +static void papr_set_offset(struct ndctl_cmd *cmd, u32 offset) +{ + struct nd_pdsm_read_perf_stats *stats = cmd_to_read_perf(cmd); + if (stats == NULL) + papr_err(cmd->dimm, "Invalid command\n"); + stats->in_offset = offset; +} + +/* Fetch dimm stats and return a command to read them */ +static struct ndctl_cmd * papr_new_stats(struct ndctl_dimm * dimm) +{ + struct dimm_priv * p = dimm->dimm_user_data; + struct ndctl_cmd * cmd = NULL; + int rc; + + /* + * Submit a pdsm FETCH_PERF_STATS to get the latest stats fetched from + * PHYP and have their length returned to libndctl. Next allocate + * suitable size buffer in dimm private buffer 'perf_stats' and create + * an iterable command for pdsm READ_PERF_STATS to read these stats + * from kernel to 'perf_stats' + */ + cmd = allocate_cmd(dimm, PAPR_SCM_PDSM_FETCH_PERF_STATS, + sizeof (struct nd_pdsm_fetch_perf_stats), + ND_PDSM_FETCH_PERF_STATS_VERSION); + if (!cmd) { + papr_err(dimm, "Unable to allocate cmd for perf_stats size\n"); + return NULL; + } + + papr_dbg(dimm, "Fetching dimm stats from papr_scm\n"); + cmd->pkg[0].nd_size_out = ND_PDSM_ENVELOPE_CONTENT_SIZE( + struct nd_pdsm_fetch_perf_stats); + + /* If successful update the dimm data with length of dimm stats */ + rc = ndctl_cmd_submit_xlat(cmd); + rc = rc ? rc : update_dimm_stats(dimm, cmd); + + ndctl_cmd_unref(cmd); + if (rc) { + papr_err(dimm, "Error fetching perf stats. Err=%d\n", rc); + return NULL; + } + + /* allocate pdsm READ_PERF_STATS command having tail xfer buffer */ + cmd = allocate_cmd(dimm, PAPR_SCM_PDSM_READ_PERF_STATS, + sizeof(struct nd_pdsm_read_perf_stats) + GET_PERF_STAT_XFER_SIZE, + ND_PDSM_READ_PERF_STATS_VERSION); + if (!cmd) { + papr_err(dimm, "Unable to allocated read_perf_stats cmd\n"); + return NULL; + } /* Update the expected out size from the papr_scm module */ + + cmd->pkg[0].nd_size_out = + ND_PDSM_ENVELOPE_CONTENT_SIZE(struct nd_pdsm_read_perf_stats) + + GET_PERF_STAT_XFER_SIZE; + + /* Setup the iterators */ + cmd->iter.total_buf = (char *) p->perf_stats; + cmd->iter.init_offset = 0; + cmd->iter.max_xfer = GET_PERF_STAT_XFER_SIZE; + cmd->iter.total_xfer = p->len_perf_stats; + cmd->iter.dir = READ; + cmd->iter.data = (u8*)cmd_to_read_perf(cmd)->stats_data; + + /* setup the callbacks */ + cmd->get_xfer = papr_get_xfer; + cmd->get_offset = papr_get_offset; + cmd->set_xfer = papr_set_xfer; + cmd->set_offset = papr_set_offset; + + return cmd; +} + struct ndctl_dimm_ops * const papr_scm_dimm_ops = &(struct ndctl_dimm_ops) { .cmd_is_supported = papr_cmd_is_supported, .dimm_init = papr_dimm_init, @@ -299,4 +467,5 @@ struct ndctl_dimm_ops * const papr_scm_dimm_ops = &(struct ndctl_dimm_ops) { .new_smart = papr_new_smart_health, .smart_get_health = papr_smart_get_health, .smart_get_shutdown_state = papr_smart_get_shutdown_state, + .new_stats = papr_new_stats, }; diff --git a/ndctl/lib/papr_scm_pdsm.h b/ndctl/lib/papr_scm_pdsm.h index 9b1fdd894a6e..f9f463e6b7dd 100644 --- a/ndctl/lib/papr_scm_pdsm.h +++ b/ndctl/lib/papr_scm_pdsm.h @@ -114,6 +114,8 @@ struct nd_pdsm_cmd_pkg { enum papr_scm_pdsm { PAPR_SCM_PDSM_MIN = 0x0, PAPR_SCM_PDSM_HEALTH, + PAPR_SCM_PDSM_FETCH_PERF_STATS, + PAPR_SCM_PDSM_READ_PERF_STATS, PAPR_SCM_PDSM_MAX, }; @@ -170,4 +172,50 @@ struct nd_papr_pdsm_health_v1 { /* Current version number for the dimm health struct */ #define ND_PAPR_PDSM_HEALTH_VERSION 1 +/* + * Return the maximum buffer size needed to hold all performance state. + * max_stats_size: The buffer size needed to hold all stat entries + */ +struct nd_pdsm_fetch_perf_stats_v1 { + __u32 max_stats_size; + __u8 reserved[4]; +} __attribute__((packed)); + +#define nd_pdsm_fetch_perf_stats nd_pdsm_fetch_perf_stats_v1 +#define ND_PDSM_FETCH_PERF_STATS_VERSION 1 + +/* + * Holds a single performance stat. papr_scm owns a buffer that holds an array + * of all the available stats and their values. Access to the buffer is provided + * via PERF_STAT_SIZE and READ_PERF_STATS psdm. + * id : id of the performance stat. Usually acsii encode stat name. + * val : Non normalized value of the id. + */ + +struct nd_pdsm_perf_stat { + __u64 id; + __u64 val; +}; + +/* + * Returns a chunk of performance stats buffer data to libndctl. + * This is needed to overcome the 256 byte envelope size limit enforced by + * libnvdimm. + * in_offset: The starting offset to perf stats data buffer. + * in_length: Length of data to be copied to 'stats_data' + * stats_data: Holds the chunk of requested perf stats data buffer. + * + * Note: To prevent races in reading performance stats, in_offset and in_length + * should multiple of 16-Bytes. If they are not then papr_scm will return an + * -EINVAL error. + */ +struct nd_pdsm_read_perf_stats_v1 { + __u32 in_offset; + __u32 in_length; + struct nd_pdsm_perf_stat stats_data[]; +} __attribute__((packed)); + +#define nd_pdsm_read_perf_stats nd_pdsm_read_perf_stats_v1 +#define ND_PDSM_READ_PERF_STATS_VERSION 1 + #endif /* _UAPI_ASM_POWERPC_PAPR_SCM_PDSM_H_ */ -- 2.26.2