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1/* SPDX-License-Identifier: GPL-2.0-only */2/*3 * padata.h - header for the padata parallelization interface4 *5 * Copyright (C) 2008, 2009 secunet Security Networks AG6 * 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_H13#define PADATA_H14 15#include <linux/refcount.h>16#include <linux/compiler_types.h>17#include <linux/workqueue.h>18#include <linux/spinlock.h>19#include <linux/list.h>20#include <linux/kobject.h>21 22#define PADATA_CPU_SERIAL 0x0123#define PADATA_CPU_PARALLEL 0x0224 25/**26 * struct padata_priv - Represents one job27 *28 * @list: List entry, to attach to the padata lists.29 * @pd: Pointer to the internal control structure.30 * @cb_cpu: Callback cpu for serializatioon.31 * @seq_nr: Sequence number of the parallelized data object.32 * @info: Used to pass information from the parallel to the serial function.33 * @parallel: Parallel execution function.34 * @serial: Serial complete function.35 */36struct padata_priv {37 struct list_head list;38 struct parallel_data *pd;39 int cb_cpu;40 unsigned int seq_nr;41 int info;42 void (*parallel)(struct padata_priv *padata);43 void (*serial)(struct padata_priv *padata);44};45 46/**47 * struct padata_list - one per work type per CPU48 *49 * @list: List head.50 * @lock: List lock.51 */52struct padata_list {53 struct list_head list;54 spinlock_t lock;55};56 57/**58* struct padata_serial_queue - The percpu padata serial queue59*60* @serial: List to wait for serialization after reordering.61* @work: work struct for serialization.62* @pd: Backpointer to the internal control structure.63*/64struct padata_serial_queue {65 struct padata_list serial;66 struct work_struct work;67 struct parallel_data *pd;68};69 70/**71 * struct padata_cpumask - The cpumasks for the parallel/serial workers72 *73 * @pcpu: cpumask for the parallel workers.74 * @cbcpu: cpumask for the serial (callback) workers.75 */76struct padata_cpumask {77 cpumask_var_t pcpu;78 cpumask_var_t cbcpu;79};80 81/**82 * struct parallel_data - Internal control structure, covers everything83 * that depends on the cpumask in use.84 *85 * @ps: padata_shell object.86 * @reorder_list: percpu reorder lists87 * @squeue: percpu padata queues used for serialuzation.88 * @refcnt: Number of objects holding a reference on this parallel_data.89 * @seq_nr: Sequence number of the parallelized data object.90 * @processed: Number of already processed objects.91 * @cpu: Next CPU to be processed.92 * @cpumask: The cpumasks in use for parallel and serial workers.93 * @reorder_work: work struct for reordering.94 * @lock: Reorder lock.95 */96struct parallel_data {97 struct padata_shell *ps;98 struct padata_list __percpu *reorder_list;99 struct padata_serial_queue __percpu *squeue;100 refcount_t refcnt;101 unsigned int seq_nr;102 unsigned int processed;103 int cpu;104 struct padata_cpumask cpumask;105 struct work_struct reorder_work;106 spinlock_t ____cacheline_aligned lock;107};108 109/**110 * struct padata_shell - Wrapper around struct parallel_data, its111 * purpose is to allow the underlying control structure to be replaced112 * on the fly using RCU.113 *114 * @pinst: padat instance.115 * @pd: Actual parallel_data structure which may be substituted on the fly.116 * @opd: Pointer to old pd to be freed by padata_replace.117 * @list: List entry in padata_instance list.118 */119struct padata_shell {120 struct padata_instance *pinst;121 struct parallel_data __rcu *pd;122 struct parallel_data *opd;123 struct list_head list;124};125 126/**127 * struct padata_mt_job - represents one multithreaded job128 *129 * @thread_fn: Called for each chunk of work that a padata thread does.130 * @fn_arg: The thread function argument.131 * @start: The start of the job (units are job-specific).132 * @size: size of this node's work (units are job-specific).133 * @align: Ranges passed to the thread function fall on this boundary, with the134 * possible exceptions of the beginning and end of the job.135 * @min_chunk: The minimum chunk size in job-specific units. This allows136 * the client to communicate the minimum amount of work that's137 * appropriate for one worker thread to do at once.138 * @max_threads: Max threads to use for the job, actual number may be less139 * depending on task size and minimum chunk size.140 * @numa_aware: Distribute jobs to different nodes with CPU in a round robin fashion.141 */142struct padata_mt_job {143 void (*thread_fn)(unsigned long start, unsigned long end, void *arg);144 void *fn_arg;145 unsigned long start;146 unsigned long size;147 unsigned long align;148 unsigned long min_chunk;149 int max_threads;150 bool numa_aware;151};152 153/**154 * struct padata_instance - The overall control structure.155 *156 * @cpu_online_node: Linkage for CPU online callback.157 * @cpu_dead_node: Linkage for CPU offline callback.158 * @parallel_wq: The workqueue used for parallel work.159 * @serial_wq: The workqueue used for serial work.160 * @pslist: List of padata_shell objects attached to this instance.161 * @cpumask: User supplied cpumasks for parallel and serial works.162 * @kobj: padata instance kernel object.163 * @lock: padata instance lock.164 * @flags: padata flags.165 */166struct padata_instance {167 struct hlist_node cpu_online_node;168 struct hlist_node cpu_dead_node;169 struct workqueue_struct *parallel_wq;170 struct workqueue_struct *serial_wq;171 struct list_head pslist;172 struct padata_cpumask cpumask;173 struct kobject kobj;174 struct mutex lock;175 u8 flags;176#define PADATA_INIT 1177#define PADATA_RESET 2178#define PADATA_INVALID 4179};180 181#ifdef CONFIG_PADATA182extern void __init padata_init(void);183extern struct padata_instance *padata_alloc(const char *name);184extern void padata_free(struct padata_instance *pinst);185extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);186extern void padata_free_shell(struct padata_shell *ps);187extern int padata_do_parallel(struct padata_shell *ps,188 struct padata_priv *padata, int *cb_cpu);189extern void padata_do_serial(struct padata_priv *padata);190extern void __init padata_do_multithreaded(struct padata_mt_job *job);191extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,192 cpumask_var_t cpumask);193#else194static inline void __init padata_init(void) {}195static inline void __init padata_do_multithreaded(struct padata_mt_job *job)196{197 job->thread_fn(job->start, job->start + job->size, job->fn_arg);198}199#endif200 201#endif202