[PATCH net-next v7] eth: fbnic: Add hardware monitoring support via HWMON interface

From: Sanman Pradhan
Date: Mon Oct 14 2024 - 11:30:26 EST


From: Sanman Pradhan <sanmanpradhan@xxxxxxxx>

This patch adds support for hardware monitoring to the fbnic driver,
allowing for temperature and voltage sensor data to be exposed to
userspace via the HWMON interface. The driver registers a HWMON device
and provides callbacks for reading sensor data, enabling system
admins to monitor the health and operating conditions of fbnic.

Signed-off-by: Sanman Pradhan <sanmanpradhan@xxxxxxxx>

---
v7:
- Address local variable err

v6: https://patchwork.kernel.org/project/netdevbpf/patch/20241011235847.1209435-1-sanman.p211993@xxxxxxxxx/

v5: https://patchwork.kernel.org/project/netdevbpf/patch/20241009192018.2683416-1-sanman.p211993@xxxxxxxxx/

v4: https://patchwork.kernel.org/project/netdevbpf/patch/20241008143212.2354554-1-sanman.p211993@xxxxxxxxx/

v3: https://patchwork.kernel.org/project/netdevbpf/patch/20241004204953.2223536-1-sanman.p211993@xxxxxxxxx/

v2: https://patchwork.kernel.org/project/netdevbpf/patch/20241003173618.2479520-1-sanman.p211993@xxxxxxxxx/

v1: https://lore.kernel.org/netdev/153c5be4-158e-421a-83a5-5632a9263e87@xxxxxxxxxxxx/T/

---
drivers/net/ethernet/meta/fbnic/Makefile | 1 +
drivers/net/ethernet/meta/fbnic/fbnic.h | 5 ++
drivers/net/ethernet/meta/fbnic/fbnic_fw.h | 7 ++
drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c | 81 +++++++++++++++++++
drivers/net/ethernet/meta/fbnic/fbnic_mac.c | 22 +++++
drivers/net/ethernet/meta/fbnic/fbnic_mac.h | 7 ++
drivers/net/ethernet/meta/fbnic/fbnic_pci.c | 3 +
7 files changed, 126 insertions(+)
create mode 100644 drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c

diff --git a/drivers/net/ethernet/meta/fbnic/Makefile b/drivers/net/ethernet/meta/fbnic/Makefile
index ed4533a73c57..41494022792a 100644
--- a/drivers/net/ethernet/meta/fbnic/Makefile
+++ b/drivers/net/ethernet/meta/fbnic/Makefile
@@ -11,6 +11,7 @@ fbnic-y := fbnic_devlink.o \
fbnic_ethtool.o \
fbnic_fw.o \
fbnic_hw_stats.o \
+ fbnic_hwmon.o \
fbnic_irq.o \
fbnic_mac.o \
fbnic_netdev.o \
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic.h b/drivers/net/ethernet/meta/fbnic/fbnic.h
index 0f9e8d79461c..ff0ff012c8d6 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic.h
@@ -18,6 +18,7 @@
struct fbnic_dev {
struct device *dev;
struct net_device *netdev;
+ struct device *hwmon;

u32 __iomem *uc_addr0;
u32 __iomem *uc_addr4;
@@ -30,6 +31,7 @@ struct fbnic_dev {

struct fbnic_fw_mbx mbx[FBNIC_IPC_MBX_INDICES];
struct fbnic_fw_cap fw_cap;
+ struct fbnic_fw_completion *cmpl_data;
/* Lock protecting Tx Mailbox queue to prevent possible races */
spinlock_t fw_tx_lock;

@@ -127,6 +129,9 @@ void fbnic_devlink_unregister(struct fbnic_dev *fbd);
int fbnic_fw_enable_mbx(struct fbnic_dev *fbd);
void fbnic_fw_disable_mbx(struct fbnic_dev *fbd);

+void fbnic_hwmon_register(struct fbnic_dev *fbd);
+void fbnic_hwmon_unregister(struct fbnic_dev *fbd);
+
int fbnic_pcs_irq_enable(struct fbnic_dev *fbd);
void fbnic_pcs_irq_disable(struct fbnic_dev *fbd);

diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
index 221faf8c6756..7cd8841920e4 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_fw.h
@@ -44,6 +44,13 @@ struct fbnic_fw_cap {
u8 link_fec;
};

+struct fbnic_fw_completion {
+ struct {
+ s32 millivolts;
+ s32 millidegrees;
+ } tsene;
+};
+
void fbnic_mbx_init(struct fbnic_dev *fbd);
void fbnic_mbx_clean(struct fbnic_dev *fbd);
void fbnic_mbx_poll(struct fbnic_dev *fbd);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c b/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c
new file mode 100644
index 000000000000..bcd1086e3768
--- /dev/null
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include <linux/hwmon.h>
+
+#include "fbnic.h"
+#include "fbnic_mac.h"
+
+static int fbnic_hwmon_sensor_id(enum hwmon_sensor_types type)
+{
+ if (type == hwmon_temp)
+ return FBNIC_SENSOR_TEMP;
+ if (type == hwmon_in)
+ return FBNIC_SENSOR_VOLTAGE;
+
+ return -EOPNOTSUPP;
+}
+
+static umode_t fbnic_hwmon_is_visible(const void *drvdata,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ if (type == hwmon_temp && attr == hwmon_temp_input)
+ return 0444;
+ if (type == hwmon_in && attr == hwmon_in_input)
+ return 0444;
+
+ return 0;
+}
+
+static int fbnic_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct fbnic_dev *fbd = dev_get_drvdata(dev);
+ const struct fbnic_mac *mac = fbd->mac;
+ int id;
+
+ id = fbnic_hwmon_sensor_id(type);
+ return id < 0 ? id : mac->get_sensor(fbd, id, val);
+}
+
+static const struct hwmon_ops fbnic_hwmon_ops = {
+ .is_visible = fbnic_hwmon_is_visible,
+ .read = fbnic_hwmon_read,
+};
+
+static const struct hwmon_channel_info *fbnic_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
+ NULL
+};
+
+static const struct hwmon_chip_info fbnic_chip_info = {
+ .ops = &fbnic_hwmon_ops,
+ .info = fbnic_hwmon_info,
+};
+
+void fbnic_hwmon_register(struct fbnic_dev *fbd)
+{
+ if (!IS_REACHABLE(CONFIG_HWMON))
+ return;
+
+ fbd->hwmon = hwmon_device_register_with_info(fbd->dev, "fbnic",
+ fbd, &fbnic_chip_info,
+ NULL);
+ if (IS_ERR(fbd->hwmon)) {
+ dev_notice(fbd->dev,
+ "Failed to register hwmon device %pe\n",
+ fbd->hwmon);
+ fbd->hwmon = NULL;
+ }
+}
+
+void fbnic_hwmon_unregister(struct fbnic_dev *fbd)
+{
+ if (!IS_REACHABLE(CONFIG_HWMON) || !fbd->hwmon)
+ return;
+
+ hwmon_device_unregister(fbd->hwmon);
+ fbd->hwmon = NULL;
+}
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
index 7b654d0a6dac..80b82ff12c4d 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_mac.c
@@ -686,6 +686,27 @@ fbnic_mac_get_eth_mac_stats(struct fbnic_dev *fbd, bool reset,
MAC_STAT_TX_BROADCAST);
}

+static int fbnic_mac_get_sensor_asic(struct fbnic_dev *fbd, int id, long *val)
+{
+ struct fbnic_fw_completion fw_cmpl;
+ s32 *sensor;
+
+ switch (id) {
+ case FBNIC_SENSOR_TEMP:
+ sensor = &fw_cmpl.tsene.millidegrees;
+ break;
+ case FBNIC_SENSOR_VOLTAGE:
+ sensor = &fw_cmpl.tsene.millivolts;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ *val = *sensor;
+
+ return 0;
+}
+
static const struct fbnic_mac fbnic_mac_asic = {
.init_regs = fbnic_mac_init_regs,
.pcs_enable = fbnic_pcs_enable_asic,
@@ -695,6 +716,7 @@ static const struct fbnic_mac fbnic_mac_asic = {
.get_eth_mac_stats = fbnic_mac_get_eth_mac_stats,
.link_down = fbnic_mac_link_down_asic,
.link_up = fbnic_mac_link_up_asic,
+ .get_sensor = fbnic_mac_get_sensor_asic,
};

/**
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_mac.h b/drivers/net/ethernet/meta/fbnic/fbnic_mac.h
index 476239a9d381..05a591653e09 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_mac.h
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_mac.h
@@ -47,6 +47,11 @@ enum {
#define FBNIC_LINK_MODE_PAM4 (FBNIC_LINK_50R1)
#define FBNIC_LINK_MODE_MASK (FBNIC_LINK_AUTO - 1)

+enum fbnic_sensor_id {
+ FBNIC_SENSOR_TEMP, /* Temp in millidegrees Centigrade */
+ FBNIC_SENSOR_VOLTAGE, /* Voltage in millivolts */
+};
+
/* This structure defines the interface hooks for the MAC. The MAC hooks
* will be configured as a const struct provided with a set of function
* pointers.
@@ -83,6 +88,8 @@ struct fbnic_mac {

void (*link_down)(struct fbnic_dev *fbd);
void (*link_up)(struct fbnic_dev *fbd, bool tx_pause, bool rx_pause);
+
+ int (*get_sensor)(struct fbnic_dev *fbd, int id, long *val);
};

int fbnic_mac_init(struct fbnic_dev *fbd);
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c
index a4809fe0fc24..ef9dc8c67927 100644
--- a/drivers/net/ethernet/meta/fbnic/fbnic_pci.c
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_pci.c
@@ -289,6 +289,8 @@ static int fbnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)

fbnic_devlink_register(fbd);

+ fbnic_hwmon_register(fbd);
+
if (!fbd->dsn) {
dev_warn(&pdev->dev, "Reading serial number failed\n");
goto init_failure_mode;
@@ -345,6 +347,7 @@ static void fbnic_remove(struct pci_dev *pdev)
fbnic_netdev_free(fbd);
}

+ fbnic_hwmon_unregister(fbd);
fbnic_devlink_unregister(fbd);
fbnic_fw_disable_mbx(fbd);
fbnic_free_irqs(fbd);
--
2.43.5