From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- Documentation/hwmon/hwmon-kernel-api.rst | 402 +++++++++++++++++++++++++++++++ 1 file changed, 402 insertions(+) create mode 100644 Documentation/hwmon/hwmon-kernel-api.rst (limited to 'Documentation/hwmon/hwmon-kernel-api.rst') diff --git a/Documentation/hwmon/hwmon-kernel-api.rst b/Documentation/hwmon/hwmon-kernel-api.rst new file mode 100644 index 000000000..f3276b3a3 --- /dev/null +++ b/Documentation/hwmon/hwmon-kernel-api.rst @@ -0,0 +1,402 @@ +The Linux Hardware Monitoring kernel API +======================================== + +Guenter Roeck + +Introduction +------------ + +This document describes the API that can be used by hardware monitoring +drivers that want to use the hardware monitoring framework. + +This document does not describe what a hardware monitoring (hwmon) Driver or +Device is. It also does not describe the API which can be used by user space +to communicate with a hardware monitoring device. If you want to know this +then please read the following file: Documentation/hwmon/sysfs-interface.rst. + +For additional guidelines on how to write and improve hwmon drivers, please +also read Documentation/hwmon/submitting-patches.rst. + +The API +------- +Each hardware monitoring driver must #include and, in most +cases, . linux/hwmon.h declares the following +register/unregister functions:: + + struct device * + hwmon_device_register_with_groups(struct device *dev, const char *name, + void *drvdata, + const struct attribute_group **groups); + + struct device * + devm_hwmon_device_register_with_groups(struct device *dev, + const char *name, void *drvdata, + const struct attribute_group **groups); + + struct device * + hwmon_device_register_with_info(struct device *dev, + const char *name, void *drvdata, + const struct hwmon_chip_info *info, + const struct attribute_group **extra_groups); + + struct device * + devm_hwmon_device_register_with_info(struct device *dev, + const char *name, + void *drvdata, + const struct hwmon_chip_info *info, + const struct attribute_group **extra_groups); + + void hwmon_device_unregister(struct device *dev); + + void devm_hwmon_device_unregister(struct device *dev); + + char *hwmon_sanitize_name(const char *name); + + char *devm_hwmon_sanitize_name(struct device *dev, const char *name); + +hwmon_device_register_with_groups registers a hardware monitoring device. +The first parameter of this function is a pointer to the parent device. +The name parameter is a pointer to the hwmon device name. The registration +function wil create a name sysfs attribute pointing to this name. +The drvdata parameter is the pointer to the local driver data. +hwmon_device_register_with_groups will attach this pointer to the newly +allocated hwmon device. The pointer can be retrieved by the driver using +dev_get_drvdata() on the hwmon device pointer. The groups parameter is +a pointer to a list of sysfs attribute groups. The list must be NULL terminated. +hwmon_device_register_with_groups creates the hwmon device with name attribute +as well as all sysfs attributes attached to the hwmon device. +This function returns a pointer to the newly created hardware monitoring device +or PTR_ERR for failure. + +devm_hwmon_device_register_with_groups is similar to +hwmon_device_register_with_groups. However, it is device managed, meaning the +hwmon device does not have to be removed explicitly by the removal function. + +hwmon_device_register_with_info is the most comprehensive and preferred means +to register a hardware monitoring device. It creates the standard sysfs +attributes in the hardware monitoring core, letting the driver focus on reading +from and writing to the chip instead of having to bother with sysfs attributes. +The parent device parameter as well as the chip parameter must not be NULL. Its +parameters are described in more detail below. + +devm_hwmon_device_register_with_info is similar to +hwmon_device_register_with_info. However, it is device managed, meaning the +hwmon device does not have to be removed explicitly by the removal function. + +hwmon_device_unregister deregisters a registered hardware monitoring device. +The parameter of this function is the pointer to the registered hardware +monitoring device structure. This function must be called from the driver +remove function if the hardware monitoring device was registered with +hwmon_device_register_with_groups or hwmon_device_register_with_info. + +devm_hwmon_device_unregister does not normally have to be called. It is only +needed for error handling, and only needed if the driver probe fails after +the call to devm_hwmon_device_register_with_groups or +hwmon_device_register_with_info and if the automatic (device managed) +removal would be too late. + +All supported hwmon device registration functions only accept valid device +names. Device names including invalid characters (whitespace, '*', or '-') +will be rejected. The 'name' parameter is mandatory. + +If the driver doesn't use a static device name (for example it uses +dev_name()), and therefore cannot make sure the name only contains valid +characters, hwmon_sanitize_name can be used. This convenience function +will duplicate the string and replace any invalid characters with an +underscore. It will allocate memory for the new string and it is the +responsibility of the caller to release the memory when the device is +removed. + +devm_hwmon_sanitize_name is the resource managed version of +hwmon_sanitize_name; the memory will be freed automatically on device +removal. + +Using devm_hwmon_device_register_with_info() +-------------------------------------------- + +hwmon_device_register_with_info() registers a hardware monitoring device. +The parameters to this function are + +=============================================== =============================================== +`struct device *dev` Pointer to parent device +`const char *name` Device name +`void *drvdata` Driver private data +`const struct hwmon_chip_info *info` Pointer to chip description. +`const struct attribute_group **extra_groups` Null-terminated list of additional non-standard + sysfs attribute groups. +=============================================== =============================================== + +This function returns a pointer to the created hardware monitoring device +on success and a negative error code for failure. + +The hwmon_chip_info structure looks as follows:: + + struct hwmon_chip_info { + const struct hwmon_ops *ops; + const struct hwmon_channel_info **info; + }; + +It contains the following fields: + +* ops: + Pointer to device operations. +* info: + NULL-terminated list of device channel descriptors. + +The list of hwmon operations is defined as:: + + struct hwmon_ops { + umode_t (*is_visible)(const void *, enum hwmon_sensor_types type, + u32 attr, int); + int (*read)(struct device *, enum hwmon_sensor_types type, + u32 attr, int, long *); + int (*write)(struct device *, enum hwmon_sensor_types type, + u32 attr, int, long); + }; + +It defines the following operations. + +* is_visible: + Pointer to a function to return the file mode for each supported + attribute. This function is mandatory. + +* read: + Pointer to a function for reading a value from the chip. This function + is optional, but must be provided if any readable attributes exist. + +* write: + Pointer to a function for writing a value to the chip. This function is + optional, but must be provided if any writeable attributes exist. + +Each sensor channel is described with struct hwmon_channel_info, which is +defined as follows:: + + struct hwmon_channel_info { + enum hwmon_sensor_types type; + u32 *config; + }; + +It contains following fields: + +* type: + The hardware monitoring sensor type. + + Supported sensor types are + + ================== ================================================== + hwmon_chip A virtual sensor type, used to describe attributes + which are not bound to a specific input or output + hwmon_temp Temperature sensor + hwmon_in Voltage sensor + hwmon_curr Current sensor + hwmon_power Power sensor + hwmon_energy Energy sensor + hwmon_humidity Humidity sensor + hwmon_fan Fan speed sensor + hwmon_pwm PWM control + ================== ================================================== + +* config: + Pointer to a 0-terminated list of configuration values for each + sensor of the given type. Each value is a combination of bit values + describing the attributes supposed by a single sensor. + +As an example, here is the complete description file for a LM75 compatible +sensor chip. The chip has a single temperature sensor. The driver wants to +register with the thermal subsystem (HWMON_C_REGISTER_TZ), and it supports +the update_interval attribute (HWMON_C_UPDATE_INTERVAL). The chip supports +reading the temperature (HWMON_T_INPUT), it has a maximum temperature +register (HWMON_T_MAX) as well as a maximum temperature hysteresis register +(HWMON_T_MAX_HYST):: + + static const u32 lm75_chip_config[] = { + HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL, + 0 + }; + + static const struct hwmon_channel_info lm75_chip = { + .type = hwmon_chip, + .config = lm75_chip_config, + }; + + static const u32 lm75_temp_config[] = { + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST, + 0 + }; + + static const struct hwmon_channel_info lm75_temp = { + .type = hwmon_temp, + .config = lm75_temp_config, + }; + + static const struct hwmon_channel_info *lm75_info[] = { + &lm75_chip, + &lm75_temp, + NULL + }; + + The HWMON_CHANNEL_INFO() macro can and should be used when possible. + With this macro, the above example can be simplified to + + static const struct hwmon_channel_info *lm75_info[] = { + HWMON_CHANNEL_INFO(chip, + HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST), + NULL + }; + + The remaining declarations are as follows. + + static const struct hwmon_ops lm75_hwmon_ops = { + .is_visible = lm75_is_visible, + .read = lm75_read, + .write = lm75_write, + }; + + static const struct hwmon_chip_info lm75_chip_info = { + .ops = &lm75_hwmon_ops, + .info = lm75_info, + }; + +A complete list of bit values indicating individual attribute support +is defined in include/linux/hwmon.h. Definition prefixes are as follows. + +=============== ================================================= +HWMON_C_xxxx Chip attributes, for use with hwmon_chip. +HWMON_T_xxxx Temperature attributes, for use with hwmon_temp. +HWMON_I_xxxx Voltage attributes, for use with hwmon_in. +HWMON_C_xxxx Current attributes, for use with hwmon_curr. + Notice the prefix overlap with chip attributes. +HWMON_P_xxxx Power attributes, for use with hwmon_power. +HWMON_E_xxxx Energy attributes, for use with hwmon_energy. +HWMON_H_xxxx Humidity attributes, for use with hwmon_humidity. +HWMON_F_xxxx Fan speed attributes, for use with hwmon_fan. +HWMON_PWM_xxxx PWM control attributes, for use with hwmon_pwm. +=============== ================================================= + +Driver callback functions +------------------------- + +Each driver provides is_visible, read, and write functions. Parameters +and return values for those functions are as follows:: + + umode_t is_visible_func(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) + +Parameters: + data: + Pointer to device private data structure. + type: + The sensor type. + attr: + Attribute identifier associated with a specific attribute. + For example, the attribute value for HWMON_T_INPUT would be + hwmon_temp_input. For complete mappings of bit fields to + attribute values please see include/linux/hwmon.h. + channel: + The sensor channel number. + +Return value: + The file mode for this attribute. Typically, this will be 0 (the + attribute will not be created), S_IRUGO, or 'S_IRUGO | S_IWUSR'. + +:: + + int read_func(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) + +Parameters: + dev: + Pointer to the hardware monitoring device. + type: + The sensor type. + attr: + Attribute identifier associated with a specific attribute. + For example, the attribute value for HWMON_T_INPUT would be + hwmon_temp_input. For complete mappings please see + include/linux/hwmon.h. + channel: + The sensor channel number. + val: + Pointer to attribute value. + +Return value: + 0 on success, a negative error number otherwise. + +:: + + int write_func(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) + +Parameters: + dev: + Pointer to the hardware monitoring device. + type: + The sensor type. + attr: + Attribute identifier associated with a specific attribute. + For example, the attribute value for HWMON_T_INPUT would be + hwmon_temp_input. For complete mappings please see + include/linux/hwmon.h. + channel: + The sensor channel number. + val: + The value to write to the chip. + +Return value: + 0 on success, a negative error number otherwise. + + +Driver-provided sysfs attributes +-------------------------------- + +If the hardware monitoring device is registered with +hwmon_device_register_with_info or devm_hwmon_device_register_with_info, +it is most likely not necessary to provide sysfs attributes. Only additional +non-standard sysfs attributes need to be provided when one of those registration +functions is used. + +The header file linux/hwmon-sysfs.h provides a number of useful macros to +declare and use hardware monitoring sysfs attributes. + +In many cases, you can use the exsting define DEVICE_ATTR or its variants +DEVICE_ATTR_{RW,RO,WO} to declare such attributes. This is feasible if an +attribute has no additional context. However, in many cases there will be +additional information such as a sensor index which will need to be passed +to the sysfs attribute handling function. + +SENSOR_DEVICE_ATTR and SENSOR_DEVICE_ATTR_2 can be used to define attributes +which need such additional context information. SENSOR_DEVICE_ATTR requires +one additional argument, SENSOR_DEVICE_ATTR_2 requires two. + +Simplified variants of SENSOR_DEVICE_ATTR and SENSOR_DEVICE_ATTR_2 are available +and should be used if standard attribute permissions and function names are +feasible. Standard permissions are 0644 for SENSOR_DEVICE_ATTR[_2]_RW, +0444 for SENSOR_DEVICE_ATTR[_2]_RO, and 0200 for SENSOR_DEVICE_ATTR[_2]_WO. +Standard functions, similar to DEVICE_ATTR_{RW,RO,WO}, have _show and _store +appended to the provided function name. + +SENSOR_DEVICE_ATTR and its variants define a struct sensor_device_attribute +variable. This structure has the following fields:: + + struct sensor_device_attribute { + struct device_attribute dev_attr; + int index; + }; + +You can use to_sensor_dev_attr to get the pointer to this structure from the +attribute read or write function. Its parameter is the device to which the +attribute is attached. + +SENSOR_DEVICE_ATTR_2 and its variants define a struct sensor_device_attribute_2 +variable, which is defined as follows:: + + struct sensor_device_attribute_2 { + struct device_attribute dev_attr; + u8 index; + u8 nr; + }; + +Use to_sensor_dev_attr_2 to get the pointer to this structure. Its parameter +is the device to which the attribute is attached. -- cgit v1.2.3