[PATCH v4 13/31] firmware: arm_scmi: Add Telemetry notification support
Cristian Marussi
cristian.marussi at arm.com
Fri Jun 12 15:37:43 PDT 2026
Add support for notifications to Telemetry protocol and register an
internal notifier during protocol initialization: any DE value received
inside a notification payload will be cached for future user consumption.
Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
v3 -> v4
- use TDE cache to save DEs received via msg payload
v2 --> v3
- changed a few dev_err into traces
- split from monolithic telemetry protocol patch
- use memcpy_from_le32
---
drivers/firmware/arm_scmi/telemetry.c | 143 +++++++++++++++++++++++---
include/linux/scmi_protocol.h | 9 ++
2 files changed, 138 insertions(+), 14 deletions(-)
diff --git a/drivers/firmware/arm_scmi/telemetry.c b/drivers/firmware/arm_scmi/telemetry.c
index f88650916de8..41b109a194d9 100644
--- a/drivers/firmware/arm_scmi/telemetry.c
+++ b/drivers/firmware/arm_scmi/telemetry.c
@@ -464,12 +464,16 @@ struct telemetry_info {
struct list_head free_des;
struct list_head fcs_des;
struct scmi_telemetry_info info;
+ struct notifier_block telemetry_nb;
atomic_t rinfo_initializing;
struct completion rinfo_initdone;
struct scmi_telemetry_res_info __private *rinfo;
struct scmi_telemetry_res_info *(*res_get)(struct telemetry_info *ti);
};
+#define telemetry_nb_to_info(x) \
+ container_of(x, struct telemetry_info, telemetry_nb)
+
static struct scmi_telemetry_res_info *
__scmi_telemetry_resources_get(struct telemetry_info *ti);
@@ -1645,7 +1649,6 @@ static void scmi_telemetry_tdcf_data_parse(struct telemetry_info *ti,
/* Parse data words ... only for the sake of updating TDE cache */
scmi_telemetry_line_data_parse(tde, &sample, payld, shmti->last_magic);
-
}
static int scmi_telemetry_tdcf_line_parse(struct telemetry_info *ti,
@@ -2432,6 +2435,7 @@ scmi_telemetry_msg_payld_process(struct telemetry_info *ti,
while (next < num_dwords) {
struct payload *payld = (struct payload *)&dwords[next];
+ struct scmi_telemetry_de_sample sample = {};
struct scmi_telemetry_de *de;
struct telemetry_de *tde;
u32 de_id;
@@ -2439,29 +2443,29 @@ scmi_telemetry_msg_payld_process(struct telemetry_info *ti,
next += LINE_LENGTH_WORDS(payld);
if (DATA_INVALID(payld)) {
- dev_err(ti->ph->dev, "MSG - Received INVALID DATA line\n");
+ trace_scmi_tlm_access(PAYLD_ID(payld), "MSG_INVALID", 0, 0);
continue;
}
de_id = le32_to_cpu(payld->id);
de = xa_load(&ti->xa_des, de_id);
if (!de || !de->enabled) {
- dev_err(ti->ph->dev,
- "MSG - Received INVALID DE - ID:%u enabled:%c\n",
- de_id, de ? (de->enabled ? 'Y' : 'N') : 'X');
+ trace_scmi_tlm_access(de_id, de ? "MSG_DE_DISABLED" :
+ "MSG_DE_UNKNOWN", 0, 0);
continue;
}
- tde = to_tde(de);
- guard(mutex)(&tde->mtx);
- tde->cached_msg = true;
- tde->last_val = LINE_DATA_GET(&payld->tsl);
- /* TODO BLK_TS in notification payloads */
- tde->last_ts = HAS_LINE_EXT(payld) && LINE_TS_VALID(payld) ?
+ sample.val = LINE_DATA_GET(&payld->tsl);
+ sample.tstamp = HAS_LINE_EXT(payld) && LINE_TS_VALID(payld) ?
LINE_TSTAMP_GET(&payld->tsl) : 0;
- trace_scmi_tlm_collect(tde->last_ts, tde->de.info->id,
- tde->last_val, "MESSAGE");
+ /* Trace originally read tstamp */
+ trace_scmi_tlm_collect(sample.tstamp, de->info->id, sample.val,
+ "MESSAGE");
+
+ tde = to_tde(de);
+ tde->cached_msg = true;
+ scmi_telemetry_tde_cache_update(tde, &sample, NULL);
}
}
@@ -2576,6 +2580,98 @@ static const struct scmi_telemetry_proto_ops tlm_proto_ops = {
.reset = scmi_telemetry_reset,
};
+static bool
+scmi_telemetry_notify_supported(const struct scmi_protocol_handle *ph,
+ u8 evt_id, u32 src_id)
+{
+ struct telemetry_info *ti = ph->get_priv(ph);
+
+ return ti->info.continuos_update_support;
+}
+
+static int
+scmi_telemetry_set_notify_enabled(const struct scmi_protocol_handle *ph,
+ u8 evt_id, u32 src_id, bool enable)
+{
+ return 0;
+}
+
+static void *
+scmi_telemetry_fill_custom_report(const struct scmi_protocol_handle *ph,
+ u8 evt_id, ktime_t timestamp,
+ const void *payld, size_t payld_sz,
+ void *report, u32 *src_id)
+{
+ const struct scmi_telemetry_update_notify_payld *p = payld;
+ struct scmi_telemetry_update_report *r = report;
+
+ /* At least sized as an empty notification */
+ if (payld_sz < sizeof(*p))
+ return NULL;
+
+ r->timestamp = timestamp;
+ r->agent_id = le32_to_cpu(p->agent_id);
+ r->status = le32_to_cpu(p->status);
+ r->num_dwords = le32_to_cpu(p->num_dwords);
+ /*
+ * Allocated dwords and report are sized as max_msg_size, so as
+ * to allow for the maximum payload permitted by the configured
+ * transport. Overflow is not possible since out-of-size messages
+ * are dropped at the transport layer.
+ */
+ if (r->num_dwords)
+ memcpy_from_le32(r->dwords, p->array, r->num_dwords);
+
+ *src_id = 0;
+
+ return r;
+}
+
+static const struct scmi_event tlm_events[] = {
+ {
+ .id = SCMI_EVENT_TELEMETRY_UPDATE,
+ .max_payld_sz = 0,
+ .max_report_sz = 0,
+ },
+};
+
+static const struct scmi_event_ops tlm_event_ops = {
+ .is_notify_supported = scmi_telemetry_notify_supported,
+ .set_notify_enabled = scmi_telemetry_set_notify_enabled,
+ .fill_custom_report = scmi_telemetry_fill_custom_report,
+};
+
+static const struct scmi_protocol_events tlm_protocol_events = {
+ .queue_sz = SCMI_PROTO_QUEUE_SZ,
+ .ops = &tlm_event_ops,
+ .evts = tlm_events,
+ .num_events = ARRAY_SIZE(tlm_events),
+ .num_sources = 1,
+};
+
+static int scmi_telemetry_notifier(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct scmi_telemetry_update_report *er = data;
+ struct telemetry_info *ti = telemetry_nb_to_info(nb);
+
+ if (er->status) {
+ trace_scmi_tlm_access(0, "BAD_NOTIF_MSG", 0, 0);
+ return NOTIFY_DONE;
+ }
+
+ trace_scmi_tlm_access(0, "TLM_UPDATE_MSG", 0, 0);
+ /* Lookup the embedded DEs in the notification payload ... */
+ if (er->num_dwords)
+ scmi_telemetry_msg_payld_process(ti, er->num_dwords, er->dwords);
+
+ /* ...scan the SHMTI/FCs for any other DE updates. */
+ if (ti->streaming_mode)
+ scmi_telemetry_scan_update(ti);
+
+ return NOTIFY_OK;
+}
+
/**
* scmi_telemetry_resources_alloc - Resources allocation
* @ti: A reference to the telemetry info descriptor for this instance
@@ -2824,7 +2920,25 @@ static int scmi_telemetry_protocol_init(const struct scmi_protocol_handle *ph)
ti->info.base.version = ph->version;
- return ph->set_priv(ph, ti);
+ ret = ph->set_priv(ph, ti);
+ if (ret)
+ return ret;
+
+ /*
+ * Register a notifier anyway straight upon protocol initialization
+ * since there could be some DEs that are ONLY reported by notifications
+ * even though the chosen collection method was SHMTI/FCs.
+ */
+ if (ti->info.continuos_update_support) {
+ ti->telemetry_nb.notifier_call = &scmi_telemetry_notifier;
+ ret = ph->notifier_register(ph, SCMI_EVENT_TELEMETRY_UPDATE,
+ NULL, &ti->telemetry_nb);
+ if (ret)
+ dev_warn(ph->dev,
+ "Could NOT register Telemetry notifications\n");
+ }
+
+ return ret;
}
static const struct scmi_protocol scmi_telemetry = {
@@ -2832,6 +2946,7 @@ static const struct scmi_protocol scmi_telemetry = {
.owner = THIS_MODULE,
.instance_init = &scmi_telemetry_protocol_init,
.ops = &tlm_proto_ops,
+ .events = &tlm_protocol_events,
.supported_version = SCMI_PROTOCOL_SUPPORTED_VERSION,
};
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 06baa4ddc55f..568fb7bb1a76 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -1199,6 +1199,7 @@ enum scmi_notification_events {
SCMI_EVENT_SYSTEM_POWER_STATE_NOTIFIER = 0x0,
SCMI_EVENT_POWERCAP_CAP_CHANGED = 0x0,
SCMI_EVENT_POWERCAP_MEASUREMENTS_CHANGED = 0x1,
+ SCMI_EVENT_TELEMETRY_UPDATE = 0x0,
};
struct scmi_power_state_changed_report {
@@ -1286,4 +1287,12 @@ struct scmi_powercap_meas_changed_report {
unsigned int domain_id;
unsigned int power;
};
+
+struct scmi_telemetry_update_report {
+ ktime_t timestamp;
+ unsigned int agent_id;
+ int status;
+ unsigned int num_dwords;
+ unsigned int dwords[];
+};
#endif /* _LINUX_SCMI_PROTOCOL_H */
--
2.54.0
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