[PATCH net-next 6/6] eth: fbnic: firmware notifies hwmon on sensor threshold events
From: Zinc Lim
Date: Tue Jul 21 2026 - 18:29:07 EST
The firmware sends an unsolicited message via the new
FBNIC_TLV_MSG_ID_SENSOR_THRESHOLD_EXCEEDED_RESP IPC message when a
temperature or voltage sensor crosses one of its thresholds. Parse this
message and translate it into the corresponding hwmon alarm
(temp1_{min,max,crit}_alarm or in0_{min,max}_alarm) via
hwmon_notify_event(), so userspace listeners are woken on the relevant
sysfs attribute.
fbnic_hwmon_notify_event() is driven from the FW mailbox IRQ path, so it
can run concurrently with hwmon registration and teardown. Guard the
publish/teardown of fbd->hwmon: register publishes it with WRITE_ONCE()
only after a successful registration (and leaves it NULL on failure),
unregister clears it with WRITE_ONCE(NULL) and then
synchronize_irq(fbd->fw_msix_vector) to drain any in-flight mailbox IRQ
before unregistering, and notify_event reads it once with READ_ONCE() and
skips the notification when it is NULL.
Signed-off-by: Zinc Lim <limzhineng2@xxxxxxxxx>
---
drivers/net/ethernet/meta/fbnic/fbnic.h | 1 +
drivers/net/ethernet/meta/fbnic/fbnic_fw.c | 54 +++++++++++++++
drivers/net/ethernet/meta/fbnic/fbnic_fw.h | 9 +++
drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c | 68 ++++++++++++++++---
4 files changed, 124 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic.h b/drivers/net/ethernet/meta/fbnic/fbnic.h
index f647ef07704b..4a49c20e4a01 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic.h
@@ -192,6 +192,7 @@ void fbnic_fw_free_mbx(struct fbnic_dev *fbd);
void fbnic_hwmon_register(struct fbnic_dev *fbd);
void fbnic_hwmon_unregister(struct fbnic_dev *fbd);
+void fbnic_hwmon_notify_event(struct fbnic_dev *fbd, int id, long val);
int fbnic_mac_request_irq(struct fbnic_dev *fbd);
void fbnic_mac_free_irq(struct fbnic_dev *fbd);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
index d814bd4041a0..6dca38076d7b 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.c
@@ -1639,6 +1639,57 @@ fbnic_fw_parser_test(void *opaque, struct fbnic_tlv_msg **results)
return err;
}
+static const struct fbnic_tlv_index fbnic_threshold_exceeded_resp_index[] = {
+ FBNIC_TLV_ATTR_S32(FBNIC_FW_TSENE_THERM_EXCEEDED_FLAG),
+ FBNIC_TLV_ATTR_S32(FBNIC_FW_TSENE_VOLT_EXCEEDED_FLAG),
+ FBNIC_TLV_ATTR_S32(FBNIC_FW_TSENE_THERMAL),
+ FBNIC_TLV_ATTR_S32(FBNIC_FW_TSENE_VOLTAGE),
+ FBNIC_TLV_ATTR_LAST
+};
+
+static int fbnic_fw_parse_threshold_exceeded_resp(void *opaque,
+ struct fbnic_tlv_msg **results)
+{
+ bool therm_exceeded, volt_exceeded;
+ struct fbnic_dev *fbd = opaque;
+ s32 value;
+
+ therm_exceeded =
+ fta_get_sint(results, FBNIC_FW_TSENE_THERM_EXCEEDED_FLAG);
+ volt_exceeded =
+ fta_get_sint(results, FBNIC_FW_TSENE_VOLT_EXCEEDED_FLAG);
+
+ if (!therm_exceeded && !volt_exceeded) {
+ dev_err(fbd->dev,
+ "Threshold exceeded message with no flag set\n");
+ return -EINVAL;
+ }
+
+ if (therm_exceeded) {
+ if (!results[FBNIC_FW_TSENE_THERMAL]) {
+ dev_err(fbd->dev,
+ "Thermal threshold exceeded but no value received\n");
+ return -EINVAL;
+ }
+ value = fta_get_sint(results, FBNIC_FW_TSENE_THERMAL);
+ dev_err(fbd->dev, "Thermal threshold exceeded: %d mC\n", value);
+ fbnic_hwmon_notify_event(fbd, FBNIC_SENSOR_TEMP, value);
+ }
+
+ if (volt_exceeded) {
+ if (!results[FBNIC_FW_TSENE_VOLTAGE]) {
+ dev_err(fbd->dev,
+ "Voltage threshold exceeded but no value received\n");
+ return -EINVAL;
+ }
+ value = fta_get_sint(results, FBNIC_FW_TSENE_VOLTAGE);
+ dev_err(fbd->dev, "Voltage threshold exceeded: %d mV\n", value);
+ fbnic_hwmon_notify_event(fbd, FBNIC_SENSOR_VOLTAGE, value);
+ }
+
+ return 0;
+}
+
static const struct fbnic_tlv_parser fbnic_fw_tlv_parser[] = {
FBNIC_TLV_PARSER(TEST, fbnic_tlv_test_index, fbnic_fw_parser_test),
FBNIC_TLV_PARSER(FW_CAP_RESP, fbnic_fw_cap_resp_index,
@@ -1667,6 +1718,9 @@ static const struct fbnic_tlv_parser fbnic_fw_tlv_parser[] = {
FBNIC_TLV_PARSER(TSENE_READ_RESP,
fbnic_tsene_read_resp_index,
fbnic_fw_parse_tsene_read_resp),
+ FBNIC_TLV_PARSER(SENSOR_THRESHOLD_EXCEEDED_RESP,
+ fbnic_threshold_exceeded_resp_index,
+ fbnic_fw_parse_threshold_exceeded_resp),
FBNIC_TLV_PARSER(LOG_MSG_REQ,
fbnic_fw_log_req_index,
fbnic_fw_parse_log_req),
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
index 68ffd49e0cdd..87301e608255 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
@@ -227,6 +227,7 @@ enum {
FBNIC_TLV_MSG_ID_QSFP_READ_RESP = 0x39,
FBNIC_TLV_MSG_ID_TSENE_READ_REQ = 0x3C,
FBNIC_TLV_MSG_ID_TSENE_READ_RESP = 0x3D,
+ FBNIC_TLV_MSG_ID_SENSOR_THRESHOLD_EXCEEDED_RESP = 0x40,
FBNIC_TLV_MSG_ID_LOG_SEND_LOGS_REQ = 0x43,
FBNIC_TLV_MSG_ID_LOG_MSG_REQ = 0x44,
FBNIC_TLV_MSG_ID_LOG_MSG_RESP = 0x45,
@@ -296,6 +297,14 @@ enum {
FBNIC_FW_TSENE_MSG_MAX
};
+enum {
+ FBNIC_FW_TSENE_THERM_EXCEEDED_FLAG = 0x0,
+ FBNIC_FW_TSENE_VOLT_EXCEEDED_FLAG = 0x1,
+ FBNIC_FW_TSENE_THERMAL = 0x2,
+ FBNIC_FW_TSENE_VOLTAGE = 0x3,
+ FBNIC_FW_TSENE_EXCEEDED_MSG_MAX,
+};
+
enum {
FBNIC_FW_OWNERSHIP_FLAG = 0x0,
FBNIC_FW_OWNERSHIP_TIME = 0x1,
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c b/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c
index c5cddd9cef12..eb910ba47f37 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c
@@ -207,6 +207,8 @@ static const struct hwmon_chip_info fbnic_chip_info = {
void fbnic_hwmon_register(struct fbnic_dev *fbd)
{
+ struct device *hwmon;
+
if (!IS_REACHABLE(CONFIG_HWMON))
return;
@@ -214,22 +216,72 @@ void fbnic_hwmon_register(struct fbnic_dev *fbd)
fbd->hwmon_cache.temp_mdeg = FBNIC_SENSOR_NO_DATA;
fbd->hwmon_cache.volt_mv = FBNIC_SENSOR_NO_DATA;
- fbd->hwmon = hwmon_device_register_with_info(fbd->dev, "fbnic",
- fbd, &fbnic_chip_info,
- NULL);
- if (IS_ERR(fbd->hwmon)) {
+ hwmon = hwmon_device_register_with_info(fbd->dev, "fbnic", fbd,
+ &fbnic_chip_info, NULL);
+ if (IS_ERR(hwmon)) {
dev_notice(fbd->dev,
"Failed to register hwmon device %pe\n",
- fbd->hwmon);
- fbd->hwmon = NULL;
+ hwmon);
+ return;
}
+
+ WRITE_ONCE(fbd->hwmon, hwmon);
}
void fbnic_hwmon_unregister(struct fbnic_dev *fbd)
{
+ struct device *hwmon;
+
if (!IS_REACHABLE(CONFIG_HWMON) || !fbd->hwmon)
return;
- hwmon_device_unregister(fbd->hwmon);
- fbd->hwmon = NULL;
+ hwmon = fbd->hwmon;
+ /* Pair with READ_ONCE() in fbnic_hwmon_notify_event(). Publish NULL
+ * and wait for any in-flight FW mailbox IRQ handler to finish so it
+ * cannot dereference the hwmon device after we unregister it.
+ */
+ WRITE_ONCE(fbd->hwmon, NULL);
+ synchronize_irq(fbd->fw_msix_vector);
+
+ hwmon_device_unregister(hwmon);
+}
+
+void fbnic_hwmon_notify_event(struct fbnic_dev *fbd, int id, long val)
+{
+ enum hwmon_sensor_types type;
+ struct device *hwmon;
+ s32 attr = -1;
+
+ switch (id) {
+ case FBNIC_SENSOR_TEMP:
+ type = hwmon_temp;
+
+ if (val <= fbd->fw_cap.temp.min)
+ attr = hwmon_temp_min_alarm;
+ else if (val >= fbd->fw_cap.temp.crit)
+ attr = hwmon_temp_crit_alarm;
+ else if (val >= fbd->fw_cap.temp.max)
+ attr = hwmon_temp_max_alarm;
+
+ break;
+ case FBNIC_SENSOR_VOLTAGE:
+ type = hwmon_in;
+
+ if (val <= fbd->fw_cap.volt.min)
+ attr = hwmon_in_min_alarm;
+ else if (val >= fbd->fw_cap.volt.max)
+ attr = hwmon_in_max_alarm;
+
+ break;
+ default:
+ return;
+ }
+
+ /* Pair with WRITE_ONCE() in fbnic_hwmon_unregister(). Skip the
+ * notification if hwmon failed to register or has already been torn
+ * down.
+ */
+ hwmon = READ_ONCE(fbd->hwmon);
+ if (attr >= 0 && hwmon)
+ hwmon_notify_event(hwmon, type, attr, 0);
}
--
2.53.0-Meta