1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * padata.h - header for the padata parallelization interface 4 * 5 * Copyright (C) 2008, 2009 secunet Security Networks AG 6 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> 7 * 8 * Copyright (c) 2020 Oracle and/or its affiliates. 9 * Author: Daniel Jordan <daniel.m.jordan@oracle.com> 10 */ 11 12#ifndef PADATA_H 13#define PADATA_H 14 15#include <linux/compiler_types.h> 16#include <linux/workqueue.h> 17#include <linux/spinlock.h> 18#include <linux/list.h> 19#include <linux/kobject.h> 20 21#define PADATA_CPU_SERIAL 0x01 22#define PADATA_CPU_PARALLEL 0x02 23 24/** 25 * struct padata_priv - Represents one job 26 * 27 * @list: List entry, to attach to the padata lists. 28 * @pd: Pointer to the internal control structure. 29 * @cb_cpu: Callback cpu for serializatioon. 30 * @seq_nr: Sequence number of the parallelized data object. 31 * @info: Used to pass information from the parallel to the serial function. 32 * @parallel: Parallel execution function. 33 * @serial: Serial complete function. 34 */ 35struct padata_priv { 36 struct list_head list; 37 struct parallel_data *pd; 38 int cb_cpu; 39 unsigned int seq_nr; 40 int info; 41 void (*parallel)(struct padata_priv *padata); 42 void (*serial)(struct padata_priv *padata); 43}; 44 45/** 46 * struct padata_list - one per work type per CPU 47 * 48 * @list: List head. 49 * @lock: List lock. 50 */ 51struct padata_list { 52 struct list_head list; 53 spinlock_t lock; 54}; 55 56/** 57* struct padata_serial_queue - The percpu padata serial queue 58* 59* @serial: List to wait for serialization after reordering. 60* @work: work struct for serialization. 61* @pd: Backpointer to the internal control structure. 62*/ 63struct padata_serial_queue { 64 struct padata_list serial; 65 struct work_struct work; 66 struct parallel_data *pd; 67}; 68 69/** 70 * struct padata_parallel_queue - The percpu padata parallel queue 71 * 72 * @reorder: List to wait for reordering after parallel processing. 73 * @num_obj: Number of objects that are processed by this cpu. 74 */ 75struct padata_parallel_queue { 76 struct padata_list reorder; 77 atomic_t num_obj; 78}; 79 80/** 81 * struct padata_cpumask - The cpumasks for the parallel/serial workers 82 * 83 * @pcpu: cpumask for the parallel workers. 84 * @cbcpu: cpumask for the serial (callback) workers. 85 */ 86struct padata_cpumask { 87 cpumask_var_t pcpu; 88 cpumask_var_t cbcpu; 89}; 90 91/** 92 * struct parallel_data - Internal control structure, covers everything 93 * that depends on the cpumask in use. 94 * 95 * @ps: padata_shell object. 96 * @pqueue: percpu padata queues used for parallelization. 97 * @squeue: percpu padata queues used for serialuzation. 98 * @refcnt: Number of objects holding a reference on this parallel_data. 99 * @seq_nr: Sequence number of the parallelized data object. 100 * @processed: Number of already processed objects. 101 * @cpu: Next CPU to be processed. 102 * @cpumask: The cpumasks in use for parallel and serial workers. 103 * @reorder_work: work struct for reordering. 104 * @lock: Reorder lock. 105 */ 106struct parallel_data { 107 struct padata_shell *ps; 108 struct padata_parallel_queue __percpu *pqueue; 109 struct padata_serial_queue __percpu *squeue; 110 atomic_t refcnt; 111 unsigned int seq_nr; 112 unsigned int processed; 113 int cpu; 114 struct padata_cpumask cpumask; 115 struct work_struct reorder_work; 116 spinlock_t ____cacheline_aligned lock; 117}; 118 119/** 120 * struct padata_shell - Wrapper around struct parallel_data, its 121 * purpose is to allow the underlying control structure to be replaced 122 * on the fly using RCU. 123 * 124 * @pinst: padat instance. 125 * @pd: Actual parallel_data structure which may be substituted on the fly. 126 * @opd: Pointer to old pd to be freed by padata_replace. 127 * @list: List entry in padata_instance list. 128 */ 129struct padata_shell { 130 struct padata_instance *pinst; 131 struct parallel_data __rcu *pd; 132 struct parallel_data *opd; 133 struct list_head list; 134}; 135 136/** 137 * struct padata_mt_job - represents one multithreaded job 138 * 139 * @thread_fn: Called for each chunk of work that a padata thread does. 140 * @fn_arg: The thread function argument. 141 * @start: The start of the job (units are job-specific). 142 * @size: size of this node's work (units are job-specific). 143 * @align: Ranges passed to the thread function fall on this boundary, with the 144 * possible exceptions of the beginning and end of the job. 145 * @min_chunk: The minimum chunk size in job-specific units. This allows 146 * the client to communicate the minimum amount of work that's 147 * appropriate for one worker thread to do at once. 148 * @max_threads: Max threads to use for the job, actual number may be less 149 * depending on task size and minimum chunk size. 150 */ 151struct padata_mt_job { 152 void (*thread_fn)(unsigned long start, unsigned long end, void *arg); 153 void *fn_arg; 154 unsigned long start; 155 unsigned long size; 156 unsigned long align; 157 unsigned long min_chunk; 158 int max_threads; 159}; 160 161/** 162 * struct padata_instance - The overall control structure. 163 * 164 * @cpu_online_node: Linkage for CPU online callback. 165 * @cpu_dead_node: Linkage for CPU offline callback. 166 * @parallel_wq: The workqueue used for parallel work. 167 * @serial_wq: The workqueue used for serial work. 168 * @pslist: List of padata_shell objects attached to this instance. 169 * @cpumask: User supplied cpumasks for parallel and serial works. 170 * @rcpumask: Actual cpumasks based on user cpumask and cpu_online_mask. 171 * @kobj: padata instance kernel object. 172 * @lock: padata instance lock. 173 * @flags: padata flags. 174 */ 175struct padata_instance { 176 struct hlist_node cpu_online_node; 177 struct hlist_node cpu_dead_node; 178 struct workqueue_struct *parallel_wq; 179 struct workqueue_struct *serial_wq; 180 struct list_head pslist; 181 struct padata_cpumask cpumask; 182 struct padata_cpumask rcpumask; 183 struct kobject kobj; 184 struct mutex lock; 185 u8 flags; 186#define PADATA_INIT 1 187#define PADATA_RESET 2 188#define PADATA_INVALID 4 189}; 190 191#ifdef CONFIG_PADATA 192extern void __init padata_init(void); 193#else 194static inline void __init padata_init(void) {} 195#endif 196 197extern struct padata_instance *padata_alloc_possible(const char *name); 198extern void padata_free(struct padata_instance *pinst); 199extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst); 200extern void padata_free_shell(struct padata_shell *ps); 201extern int padata_do_parallel(struct padata_shell *ps, 202 struct padata_priv *padata, int *cb_cpu); 203extern void padata_do_serial(struct padata_priv *padata); 204extern void __init padata_do_multithreaded(struct padata_mt_job *job); 205extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, 206 cpumask_var_t cpumask); 207extern int padata_start(struct padata_instance *pinst); 208extern void padata_stop(struct padata_instance *pinst); 209#endif 210