/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ /* Copyright (c) 2019 Mellanox Technologies. */ #ifndef DIM_H #define DIM_H #include <linux/bits.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/types.h> #include <linux/workqueue.h> struct net_device; /* Number of DIM profiles and period mode. */ #define NET_DIM_PARAMS_NUM_PROFILES … #define NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE … #define NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE … #define NET_DIM_DEF_PROFILE_CQE … #define NET_DIM_DEF_PROFILE_EQE … /* * Number of events between DIM iterations. * Causes a moderation of the algorithm run. */ #define DIM_NEVENTS … /* * Is a difference between values justifies taking an action. * We consider 10% difference as significant. */ #define IS_SIGNIFICANT_DIFF(val, ref) … /* * Calculate the gap between two values. * Take wrap-around and variable size into consideration. */ #define BIT_GAP(bits, end, start) … /** * struct dim_cq_moder - Structure for CQ moderation values. * Used for communications between DIM and its consumer. * * @usec: CQ timer suggestion (by DIM) * @pkts: CQ packet counter suggestion (by DIM) * @comps: Completion counter * @cq_period_mode: CQ period count mode (from CQE/EQE) * @rcu: for asynchronous kfree_rcu */ struct dim_cq_moder { … }; #define DIM_PROFILE_RX … #define DIM_PROFILE_TX … #define DIM_COALESCE_USEC … #define DIM_COALESCE_PKTS … #define DIM_COALESCE_COMPS … /** * struct dim_irq_moder - Structure for irq moderation information. * Used to collect irq moderation related information. * * @profile_flags: DIM_PROFILE_* * @coal_flags: DIM_COALESCE_* for Rx and Tx * @dim_rx_mode: Rx DIM period count mode: CQE or EQE * @dim_tx_mode: Tx DIM period count mode: CQE or EQE * @rx_profile: DIM profile list for Rx * @tx_profile: DIM profile list for Tx * @rx_dim_work: Rx DIM worker scheduled by net_dim() * @tx_dim_work: Tx DIM worker scheduled by net_dim() */ struct dim_irq_moder { … }; /** * struct dim_sample - Structure for DIM sample data. * Used for communications between DIM and its consumer. * * @time: Sample timestamp * @pkt_ctr: Number of packets * @byte_ctr: Number of bytes * @event_ctr: Number of events * @comp_ctr: Current completion counter */ struct dim_sample { … }; /** * struct dim_stats - Structure for DIM stats. * Used for holding current measured rates. * * @ppms: Packets per msec * @bpms: Bytes per msec * @epms: Events per msec * @cpms: Completions per msec * @cpe_ratio: Ratio of completions to events */ struct dim_stats { … }; /** * struct dim - Main structure for dynamic interrupt moderation (DIM). * Used for holding all information about a specific DIM instance. * * @state: Algorithm state (see below) * @prev_stats: Measured rates from previous iteration (for comparison) * @start_sample: Sampled data at start of current iteration * @measuring_sample: A &dim_sample that is used to update the current events * @work: Work to perform on action required * @priv: A pointer to the struct that points to dim * @profile_ix: Current moderation profile * @mode: CQ period count mode * @tune_state: Algorithm tuning state (see below) * @steps_right: Number of steps taken towards higher moderation * @steps_left: Number of steps taken towards lower moderation * @tired: Parking depth counter */ struct dim { … }; /** * enum dim_cq_period_mode - Modes for CQ period count * * @DIM_CQ_PERIOD_MODE_START_FROM_EQE: Start counting from EQE * @DIM_CQ_PERIOD_MODE_START_FROM_CQE: Start counting from CQE (implies timer reset) * @DIM_CQ_PERIOD_NUM_MODES: Number of modes */ enum dim_cq_period_mode { … }; /** * enum dim_state - DIM algorithm states * * These will determine if the algorithm is in a valid state to start an iteration. * * @DIM_START_MEASURE: This is the first iteration (also after applying a new profile) * @DIM_MEASURE_IN_PROGRESS: Algorithm is already in progress - check if * need to perform an action * @DIM_APPLY_NEW_PROFILE: DIM consumer is currently applying a profile - no need to measure */ enum dim_state { … }; /** * enum dim_tune_state - DIM algorithm tune states * * These will determine which action the algorithm should perform. * * @DIM_PARKING_ON_TOP: Algorithm found a local top point - exit on significant difference * @DIM_PARKING_TIRED: Algorithm found a deep top point - don't exit if tired > 0 * @DIM_GOING_RIGHT: Algorithm is currently trying higher moderation levels * @DIM_GOING_LEFT: Algorithm is currently trying lower moderation levels */ enum dim_tune_state { … }; /** * enum dim_stats_state - DIM algorithm statistics states * * These will determine the verdict of current iteration. * * @DIM_STATS_WORSE: Current iteration shows worse performance than before * @DIM_STATS_SAME: Current iteration shows same performance than before * @DIM_STATS_BETTER: Current iteration shows better performance than before */ enum dim_stats_state { … }; /** * enum dim_step_result - DIM algorithm step results * * These describe the result of a step. * * @DIM_STEPPED: Performed a regular step * @DIM_TOO_TIRED: Same kind of step was done multiple times - should go to * tired parking * @DIM_ON_EDGE: Stepped to the most left/right profile */ enum dim_step_result { … }; /** * net_dim_init_irq_moder - collect information to initialize irq moderation * @dev: target network device * @profile_flags: Rx or Tx profile modification capability * @coal_flags: irq moderation params flags * @rx_mode: CQ period mode for Rx * @tx_mode: CQ period mode for Tx * @rx_dim_work: Rx worker called after dim decision * @tx_dim_work: Tx worker called after dim decision * * Return: 0 on success or a negative error code. */ int net_dim_init_irq_moder(struct net_device *dev, u8 profile_flags, u8 coal_flags, u8 rx_mode, u8 tx_mode, void (*rx_dim_work)(struct work_struct *work), void (*tx_dim_work)(struct work_struct *work)); /** * net_dim_free_irq_moder - free fields for irq moderation * @dev: target network device */ void net_dim_free_irq_moder(struct net_device *dev); /** * net_dim_setting - initialize DIM's cq mode and schedule worker * @dev: target network device * @dim: DIM context * @is_tx: true indicates the tx direction, false indicates the rx direction */ void net_dim_setting(struct net_device *dev, struct dim *dim, bool is_tx); /** * net_dim_work_cancel - synchronously cancel dim's worker * @dim: DIM context */ void net_dim_work_cancel(struct dim *dim); /** * net_dim_get_rx_irq_moder - get DIM rx results based on profile_ix * @dev: target network device * @dim: DIM context * * Return: DIM irq moderation */ struct dim_cq_moder net_dim_get_rx_irq_moder(struct net_device *dev, struct dim *dim); /** * net_dim_get_tx_irq_moder - get DIM tx results based on profile_ix * @dev: target network device * @dim: DIM context * * Return: DIM irq moderation */ struct dim_cq_moder net_dim_get_tx_irq_moder(struct net_device *dev, struct dim *dim); /** * net_dim_set_rx_mode - set DIM rx cq mode * @dev: target network device * @rx_mode: target rx cq mode */ void net_dim_set_rx_mode(struct net_device *dev, u8 rx_mode); /** * net_dim_set_tx_mode - set DIM tx cq mode * @dev: target network device * @tx_mode: target tx cq mode */ void net_dim_set_tx_mode(struct net_device *dev, u8 tx_mode); /** * dim_on_top - check if current state is a good place to stop (top location) * @dim: DIM context * * Check if current profile is a good place to park at. * This will result in reducing the DIM checks frequency as we assume we * shouldn't probably change profiles, unless traffic pattern wasn't changed. */ bool dim_on_top(struct dim *dim); /** * dim_turn - change profile altering direction * @dim: DIM context * * Go left if we were going right and vice-versa. * Do nothing if currently parking. */ void dim_turn(struct dim *dim); /** * dim_park_on_top - enter a parking state on a top location * @dim: DIM context * * Enter parking state. * Clear all movement history. */ void dim_park_on_top(struct dim *dim); /** * dim_park_tired - enter a tired parking state * @dim: DIM context * * Enter parking state. * Clear all movement history and cause DIM checks frequency to reduce. */ void dim_park_tired(struct dim *dim); /** * dim_calc_stats - calculate the difference between two samples * @start: start sample * @end: end sample * @curr_stats: delta between samples * * Calculate the delta between two samples (in data rates). * Takes into consideration counter wrap-around. * Returned boolean indicates whether curr_stats are reliable. */ bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end, struct dim_stats *curr_stats); /** * dim_update_sample - set a sample's fields with given values * @event_ctr: number of events to set * @packets: number of packets to set * @bytes: number of bytes to set * @s: DIM sample */ static inline void dim_update_sample(u16 event_ctr, u64 packets, u64 bytes, struct dim_sample *s) { … } /** * dim_update_sample_with_comps - set a sample's fields with given * values including the completion parameter * @event_ctr: number of events to set * @packets: number of packets to set * @bytes: number of bytes to set * @comps: number of completions to set * @s: DIM sample */ static inline void dim_update_sample_with_comps(u16 event_ctr, u64 packets, u64 bytes, u64 comps, struct dim_sample *s) { … } /* Net DIM */ /** * net_dim_get_rx_moderation - provide a CQ moderation object for the given RX profile * @cq_period_mode: CQ period mode * @ix: Profile index */ struct dim_cq_moder net_dim_get_rx_moderation(u8 cq_period_mode, int ix); /** * net_dim_get_def_rx_moderation - provide the default RX moderation * @cq_period_mode: CQ period mode */ struct dim_cq_moder net_dim_get_def_rx_moderation(u8 cq_period_mode); /** * net_dim_get_tx_moderation - provide a CQ moderation object for the given TX profile * @cq_period_mode: CQ period mode * @ix: Profile index */ struct dim_cq_moder net_dim_get_tx_moderation(u8 cq_period_mode, int ix); /** * net_dim_get_def_tx_moderation - provide the default TX moderation * @cq_period_mode: CQ period mode */ struct dim_cq_moder net_dim_get_def_tx_moderation(u8 cq_period_mode); /** * net_dim - main DIM algorithm entry point * @dim: DIM instance information * @end_sample: Current data measurement * * Called by the consumer. * This is the main logic of the algorithm, where data is processed in order * to decide on next required action. */ void net_dim(struct dim *dim, struct dim_sample end_sample); /* RDMA DIM */ /* * RDMA DIM profile: * profile size must be of RDMA_DIM_PARAMS_NUM_PROFILES. */ #define RDMA_DIM_PARAMS_NUM_PROFILES … #define RDMA_DIM_START_PROFILE … /** * rdma_dim - Runs the adaptive moderation. * @dim: The moderation struct. * @completions: The number of completions collected in this round. * * Each call to rdma_dim takes the latest amount of completions that * have been collected and counts them as a new event. * Once enough events have been collected the algorithm decides a new * moderation level. */ void rdma_dim(struct dim *dim, u64 completions); #endif /* DIM_H */
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