[PATCH net-next 2/4] ionic: add device interface definitions for hardware monitoring

["Nikhil P. Rao" <nikhil.rao@amd.com>]

From: Arun Kumar Prakash <ArunKumar.Prakash@amd.com>

Add the admin queue commands the device uses to describe and report its
sensors: IONIC_CMD_HWMON_GETCAPS returns a buffer enumerating the sensor
types, their channel counts and per-channel attribute capabilities, and
IONIC_CMD_HWMON_GETATTR reads a single attribute of a single channel.

The capability buffer has a variable layout that depends on the number
of sensor types the firmware supports, so it cannot be expressed as a C
struct and its format is documented in a comment instead.

The sensor types, attribute IDs and capability buffer layout go in a
new public header, include/linux/ionic/ionic_hwmon.h, because the hwmon
driver that parses the buffer lives outside the ionic directory.

Signed-off-by: Arun Kumar Prakash <ArunKumar.Prakash@amd.com>
Signed-off-by: Eric Joyner <eric.joyner@amd.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Co-developed-by: Nikhil P. Rao <nikhil.rao@amd.com>
Signed-off-by: Nikhil P. Rao <nikhil.rao@amd.com>
---
 MAINTAINERS                                      |   1 +
 drivers/net/ethernet/pensando/ionic/ionic_dev.h  |   8 ++
 drivers/net/ethernet/pensando/ionic/ionic_if.h   | 104 +++++++++++++++++
 drivers/net/ethernet/pensando/ionic/ionic_main.c |   4 +
 include/linux/ionic/ionic_hwmon.h                | 138 +++++++++++++++++++++++
 5 files changed, 255 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 09713dc4c6a7..220b26c73b37 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21804,6 +21804,7 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	Documentation/networking/device_drivers/ethernet/pensando/ionic.rst
 F:	drivers/net/ethernet/pensando/
+F:	include/linux/ionic/
 
 PER-CPU MEMORY ALLOCATOR
 M:	Dennis Zhou <dennis@kernel.org>
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index db90e39a1442..869adb0a0e0c 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -9,6 +9,7 @@
 #include <linux/workqueue.h>
 #include <linux/skbuff.h>
 #include <linux/bpf_trace.h>
+#include <linux/ionic/ionic_hwmon.h>
 
 #include "ionic_if.h"
 #include "ionic_regs.h"
@@ -116,6 +117,13 @@ static_assert(sizeof(ionic_rx_filter_del_comp) == 16);
 static_assert(sizeof(struct ionic_rdma_reset_cmd) == 64);
 static_assert(sizeof(struct ionic_rdma_queue_cmd) == 64);
 
+/* HWMON commands */
+static_assert(sizeof(struct ionic_hwmon_getattr_cmd) == 64);
+static_assert(sizeof(struct ionic_hwmon_getattr_comp) == 16);
+static_assert(sizeof(struct ionic_hwmon_getcaps_cmd) == 64);
+static_assert(sizeof(struct ionic_hwmon_getcaps_comp) == 16);
+static_assert(sizeof(struct ionic_hwmon_chan_caps) == 164);
+
 /* Events */
 static_assert(sizeof(struct ionic_notifyq_cmd) == 4);
 static_assert(sizeof(union ionic_notifyq_comp) == 64);
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_if.h b/drivers/net/ethernet/pensando/ionic/ionic_if.h
index e911fad545d6..271731a35d9f 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_if.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_if.h
@@ -60,6 +60,10 @@ enum ionic_cmd_opcode {
 	/* CMB command */
 	IONIC_CMD_DISCOVER_CMB			= 80,
 
+	/* Hardware monitoring commands */
+	IONIC_CMD_HWMON_GETATTR			= 110,
+	IONIC_CMD_HWMON_GETCAPS			= 111,
+
 	/* QoS commands */
 	IONIC_CMD_QOS_CLASS_IDENTIFY		= 240,
 	IONIC_CMD_QOS_CLASS_INIT		= 241,
@@ -274,11 +278,13 @@ union ionic_drv_identity {
  * enum ionic_dev_capability - Device capabilities
  * @IONIC_DEV_CAP_VF_CTRL:     Device supports VF ctrl operations
  * @IONIC_DEV_CAP_DISC_CMB:    Device supports CMB discovery operations
+ * @IONIC_DEV_CAP_HWMON:       Device supports hardware monitoring
  * @IONIC_DEV_CAP_EXTRA_STATS: Device supports extra stats schema
  */
 enum ionic_dev_capability {
 	IONIC_DEV_CAP_VF_CTRL        = BIT(0),
 	IONIC_DEV_CAP_DISC_CMB       = BIT(1),
+	IONIC_DEV_CAP_HWMON          = BIT(3),
 	IONIC_DEV_CAP_EXTRA_STATS    = BIT(4),
 };
 
@@ -2526,6 +2532,100 @@ struct ionic_qos_clear_stats_cmd {
 
 typedef struct ionic_admin_comp ionic_qos_reset_comp;
 
+/**
+ * struct ionic_hwmon_getattr_cmd - Hardware monitoring get attribute command
+ * @opcode:      Command opcode (IONIC_CMD_HWMON_GETATTR)
+ * @rsvd:        reserved byte(s)
+ * @lif_index:   LIF index
+ * @sensor_type: Sensor type from enum ionic_hwmon_sensor_type
+ * @channel:     Channel index within the sensor type
+ * @attr:        Attribute ID from sensor-specific attribute enum
+ * @rsvd2:       reserved byte(s)
+ *
+ * A *_ATTR_LABEL attribute ID must never be sent in this command.  The label is
+ * already reported in ionic_hwmon_chan_caps.label; the attr_caps LABEL bit only
+ * signals that a label is present.
+ */
+struct ionic_hwmon_getattr_cmd {
+	u8      opcode;
+	u8      rsvd;
+	__le16  lif_index;
+	u8      sensor_type;
+	u8      channel;
+	u8      attr;
+	u8      rsvd2[57];
+};
+
+/**
+ * struct ionic_hwmon_getattr_comp - Hardware monitor get attribute completion
+ * @status:     Status of the command (enum ionic_status_code)
+ * @rsvd:       reserved byte(s)
+ * @comp_index: Index in the descriptor ring for which this is the completion
+ * @attr_value: Attribute value
+ * @rsvd2:      reserved byte(s)
+ * @color:      Color bit
+ *
+ * attr_value depends on the (sensor_type, attr) pair being read:
+ *
+ *   temperature INPUT, CRIT   millidegrees Celsius, signed 32-bit
+ *   temperature CRIT_ALARM    0 or 1
+ *   voltage INPUT             millivolts
+ *   power INPUT, MAX          milliwatts
+ */
+struct ionic_hwmon_getattr_comp {
+	u8      status;
+	u8      rsvd;
+	__le16  comp_index;
+	__le32  attr_value;
+	u8      rsvd2[7];
+	u8      color;
+};
+
+/**
+ * struct ionic_hwmon_getcaps_cmd - Hardware monitoring get capabilities command
+ * @opcode:         Command opcode (IONIC_CMD_HWMON_GETCAPS)
+ * @ver:            Highest capability buffer layout version supported by
+ *                  the driver
+ * @lif_index:      LIF index
+ * @resp_buf_len:   Length of response buffer
+ * @resp_dma_addr:  DMA address for response data
+ * @rsvd2:          reserved byte(s)
+ *
+ * The device writes the capability buffer in the highest layout version it
+ * supports that does not exceed @ver, and reports that version in the
+ * completion.  IONIC_HWMON_CAPS_VERSION_0 is the layout documented in
+ * include/linux/ionic/ionic_hwmon.h.
+ */
+struct ionic_hwmon_getcaps_cmd {
+	u8      opcode;
+	u8      ver;
+	__le16  lif_index;
+	__le32  resp_buf_len;
+	__le64  resp_dma_addr;
+	u8      rsvd2[48];
+};
+
+/**
+ * struct ionic_hwmon_getcaps_comp - Hardware monitoring get caps completion
+ * @status:     Status of the command (enum ionic_status_code)
+ * @rsvd:       reserved byte(s)
+ * @comp_index: Index in the descriptor ring for which this is the completion
+ * @ver:        Layout version of the capability buffer written by the device
+ * @rsvd2:      reserved byte(s)
+ * @color:      Color bit
+ *
+ * Devices that predate @ver leave it zero, which is
+ * IONIC_HWMON_CAPS_VERSION_0.
+ */
+struct ionic_hwmon_getcaps_comp {
+	u8      status;
+	u8      rsvd;
+	__le16  comp_index;
+	u8      ver;
+	u8      rsvd2[10];
+	u8      color;
+};
+
 /**
  * struct ionic_fw_download_cmd - Firmware download command
  * @opcode:	opcode
@@ -3306,6 +3406,8 @@ union ionic_adminq_cmd {
 	struct ionic_rx_filter_del_cmd rx_filter_del;
 	struct ionic_rdma_reset_cmd rdma_reset;
 	struct ionic_rdma_queue_cmd rdma_queue;
+	struct ionic_hwmon_getattr_cmd hwmon_getattr;
+	struct ionic_hwmon_getcaps_cmd hwmon_getcaps;
 	struct ionic_fw_download_cmd fw_download;
 	struct ionic_fw_control_cmd fw_control;
 };
@@ -3319,6 +3421,8 @@ union ionic_adminq_comp {
 	struct ionic_lif_getattr_comp lif_getattr;
 	struct ionic_admin_comp lif_setphc;
 	struct ionic_rx_filter_add_comp rx_filter_add;
+	struct ionic_hwmon_getattr_comp hwmon_getattr;
+	struct ionic_hwmon_getcaps_comp hwmon_getcaps;
 	struct ionic_fw_control_comp fw_control;
 };
 
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_main.c b/drivers/net/ethernet/pensando/ionic/ionic_main.c
index 38b47b959a11..9955ab77d86d 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_main.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_main.c
@@ -185,6 +185,10 @@ static const char *ionic_opcode_to_str(enum ionic_cmd_opcode opcode)
 		return "IONIC_CMD_VF_GETATTR";
 	case IONIC_CMD_VF_SETATTR:
 		return "IONIC_CMD_VF_SETATTR";
+	case IONIC_CMD_HWMON_GETATTR:
+		return "IONIC_CMD_HWMON_GETATTR";
+	case IONIC_CMD_HWMON_GETCAPS:
+		return "IONIC_CMD_HWMON_GETCAPS";
 	default:
 		return "DEVCMD_UNKNOWN";
 	}
diff --git a/include/linux/ionic/ionic_hwmon.h b/include/linux/ionic/ionic_hwmon.h
new file mode 100644
index 000000000000..62667e3d7135
--- /dev/null
+++ b/include/linux/ionic/ionic_hwmon.h
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR Linux-OpenIB) OR BSD-2-Clause */
+/* Copyright(c) 2026 Advanced Micro Devices, Inc */
+
+#ifndef _LINUX_IONIC_HWMON_H_
+#define _LINUX_IONIC_HWMON_H_
+
+#include <linux/types.h>
+
+#define IONIC_HWMON_CAPS_BUF_SIZE	4096
+#define IONIC_HWMON_CAPS_VERSION_0	0
+
+/**
+ * enum ionic_hwmon_sensor_type - Hardware monitoring sensor types
+ * @IONIC_HWMON_TYPE_TEMP:      Temperature sensors
+ * @IONIC_HWMON_TYPE_VOLTAGE:   Voltage sensors
+ * @IONIC_HWMON_TYPE_POWER:     Power sensors
+ * @IONIC_HWMON_TYPE_CHIP:      Chip wide attributes
+ * @IONIC_HWMON_TYPE_CURRENT:   Current sensors
+ * @IONIC_HWMON_TYPE_ENERGY:    Energy sensors
+ * @IONIC_HWMON_TYPE_HUMIDITY:  Humidity sensors
+ * @IONIC_HWMON_TYPE_FAN:       Fan speed sensors
+ * @IONIC_HWMON_TYPE_PWM:       PWM controllers
+ * @IONIC_HWMON_TYPE_INTRUSION: Intrusion detection
+ * @IONIC_HWMON_TYPE_MAX:       Number of sensor types defined by this interface
+ *
+ * These values do not necessarily match enum hwmon_sensor_types.
+ */
+enum ionic_hwmon_sensor_type {
+	IONIC_HWMON_TYPE_TEMP		= 0,
+	IONIC_HWMON_TYPE_VOLTAGE	= 1,
+	IONIC_HWMON_TYPE_POWER		= 2,
+	IONIC_HWMON_TYPE_CHIP		= 3,
+	IONIC_HWMON_TYPE_CURRENT	= 4,
+	IONIC_HWMON_TYPE_ENERGY		= 5,
+	IONIC_HWMON_TYPE_HUMIDITY	= 6,
+	IONIC_HWMON_TYPE_FAN		= 7,
+	IONIC_HWMON_TYPE_PWM		= 8,
+	IONIC_HWMON_TYPE_INTRUSION	= 9,
+	IONIC_HWMON_TYPE_MAX		= 10,
+};
+
+/**
+ * enum ionic_hwmon_temp_attr - Temperature sensor attributes
+ * @IONIC_HWMON_TEMP_ATTR_INPUT:      Temperature input reading
+ * @IONIC_HWMON_TEMP_ATTR_LABEL:      Temperature sensor label
+ * @IONIC_HWMON_TEMP_ATTR_CRIT:       Critical temperature threshold
+ * @IONIC_HWMON_TEMP_ATTR_CRIT_ALARM: Critical temperature alarm status
+ */
+enum ionic_hwmon_temp_attr {
+	IONIC_HWMON_TEMP_ATTR_INPUT		= 0,
+	IONIC_HWMON_TEMP_ATTR_LABEL		= 1,
+	IONIC_HWMON_TEMP_ATTR_CRIT		= 2,
+	IONIC_HWMON_TEMP_ATTR_CRIT_ALARM	= 3,
+};
+
+/**
+ * enum ionic_hwmon_voltage_attr - Voltage sensor attributes
+ * @IONIC_HWMON_VOLTAGE_ATTR_INPUT: Voltage input reading
+ * @IONIC_HWMON_VOLTAGE_ATTR_LABEL: Voltage sensor label
+ */
+enum ionic_hwmon_voltage_attr {
+	IONIC_HWMON_VOLTAGE_ATTR_INPUT	= 0,
+	IONIC_HWMON_VOLTAGE_ATTR_LABEL	= 1,
+};
+
+/**
+ * enum ionic_hwmon_power_attr - Power sensor attributes
+ * @IONIC_HWMON_POWER_ATTR_INPUT: Power input reading
+ * @IONIC_HWMON_POWER_ATTR_LABEL: Power sensor label
+ * @IONIC_HWMON_POWER_ATTR_MAX:   Maximum power threshold
+ */
+enum ionic_hwmon_power_attr {
+	IONIC_HWMON_POWER_ATTR_INPUT	= 0,
+	IONIC_HWMON_POWER_ATTR_LABEL	= 1,
+	IONIC_HWMON_POWER_ATTR_MAX	= 2,
+};
+
+/**
+ * struct ionic_hwmon_chan_caps - Per-channel capability descriptor
+ * @attr_caps:  Attribute bitmask where bit N indicates attribute N is supported
+ *              (use sensor-type-specific attribute enums:
+ *              ionic_hwmon_temp_attr, ionic_hwmon_voltage_attr,
+ *              ionic_hwmon_power_attr)
+ * @mode:       Permissions for attribute N, as a single octal rwx digit
+ *              (4 = readable).  Zero hides the attribute.  Values above 7
+ *              are not a mode and hide the attribute too.
+ * @label:      NUL-terminated channel label string
+ *
+ * Every channel reports at least one attribute that its sensor type defines.
+ * Firmware that adds attributes keeps reporting one that older drivers
+ * recognise, and uses @mode to control what is visible.
+ *
+ * The structure needs to be packed since the size of n_channels in the
+ * capability buffer layout documented below is variable, so the channels
+ * array is not guaranteed to start on a 4 byte boundary.
+ */
+struct ionic_hwmon_chan_caps {
+	__le32	attr_caps;
+	__le32	mode[32];
+	char	label[32];
+} __packed;
+
+#define IONIC_HWMON_MODE_MASK		0x7
+#define IONIC_HWMON_MODE_READ		4
+
+/*
+ * Hardware monitoring capabilities buffer layout
+ *
+ * The buffer is a struct ionic_hwmon_caps_hdr followed by the channel
+ * descriptors, so where the descriptors start depends on num_types:
+ *
+ *   struct ionic_hwmon_caps_buf {
+ *       __le16  num_types;
+ *       __le16  n_channels[num_types];
+ *       struct ionic_hwmon_chan_caps channels[total_channels];
+ *   };
+ *
+ * total_channels is the sum of n_channels, and the channels of each sensor
+ * type are contiguous, in n_channels order.  A driver reads at most
+ * IONIC_HWMON_TYPE_MAX entries of n_channels and ignores the channels of
+ * any further types, which follow the ones it knows.
+ *
+ * num_types and n_channels come from the device, and the completion does not
+ * report how much was written, so a parser checks every offset against the
+ * resp_buf_len sent in IONIC_CMD_HWMON_GETCAPS.
+ */
+
+/**
+ * struct ionic_hwmon_caps_hdr - Start of the capabilities buffer
+ * @num_types:  Number of sensor types described by firmware
+ * @n_channels: Channel count for each sensor type, num_types entries
+ */
+struct ionic_hwmon_caps_hdr {
+	__le16	num_types;
+	__le16	n_channels[];
+};
+
+#endif /* _LINUX_IONIC_HWMON_H_ */

-- 
2.43.0