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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 : */ 35 : struct 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 : */ 51 : struct 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 : */ 63 : struct padata_serial_queue { 64 : struct padata_list serial; 65 : struct work_struct work; 66 : struct parallel_data *pd; 67 : }; 68 : 69 : /** 70 : * struct padata_cpumask - The cpumasks for the parallel/serial workers 71 : * 72 : * @pcpu: cpumask for the parallel workers. 73 : * @cbcpu: cpumask for the serial (callback) workers. 74 : */ 75 : struct padata_cpumask { 76 : cpumask_var_t pcpu; 77 : cpumask_var_t cbcpu; 78 : }; 79 : 80 : /** 81 : * struct parallel_data - Internal control structure, covers everything 82 : * that depends on the cpumask in use. 83 : * 84 : * @ps: padata_shell object. 85 : * @reorder_list: percpu reorder lists 86 : * @squeue: percpu padata queues used for serialuzation. 87 : * @refcnt: Number of objects holding a reference on this parallel_data. 88 : * @seq_nr: Sequence number of the parallelized data object. 89 : * @processed: Number of already processed objects. 90 : * @cpu: Next CPU to be processed. 91 : * @cpumask: The cpumasks in use for parallel and serial workers. 92 : * @reorder_work: work struct for reordering. 93 : * @lock: Reorder lock. 94 : */ 95 : struct parallel_data { 96 : struct padata_shell *ps; 97 : struct padata_list __percpu *reorder_list; 98 : struct padata_serial_queue __percpu *squeue; 99 : atomic_t refcnt; 100 : unsigned int seq_nr; 101 : unsigned int processed; 102 : int cpu; 103 : struct padata_cpumask cpumask; 104 : struct work_struct reorder_work; 105 : spinlock_t ____cacheline_aligned lock; 106 : }; 107 : 108 : /** 109 : * struct padata_shell - Wrapper around struct parallel_data, its 110 : * purpose is to allow the underlying control structure to be replaced 111 : * on the fly using RCU. 112 : * 113 : * @pinst: padat instance. 114 : * @pd: Actual parallel_data structure which may be substituted on the fly. 115 : * @opd: Pointer to old pd to be freed by padata_replace. 116 : * @list: List entry in padata_instance list. 117 : */ 118 : struct padata_shell { 119 : struct padata_instance *pinst; 120 : struct parallel_data __rcu *pd; 121 : struct parallel_data *opd; 122 : struct list_head list; 123 : }; 124 : 125 : /** 126 : * struct padata_mt_job - represents one multithreaded job 127 : * 128 : * @thread_fn: Called for each chunk of work that a padata thread does. 129 : * @fn_arg: The thread function argument. 130 : * @start: The start of the job (units are job-specific). 131 : * @size: size of this node's work (units are job-specific). 132 : * @align: Ranges passed to the thread function fall on this boundary, with the 133 : * possible exceptions of the beginning and end of the job. 134 : * @min_chunk: The minimum chunk size in job-specific units. This allows 135 : * the client to communicate the minimum amount of work that's 136 : * appropriate for one worker thread to do at once. 137 : * @max_threads: Max threads to use for the job, actual number may be less 138 : * depending on task size and minimum chunk size. 139 : */ 140 : struct padata_mt_job { 141 : void (*thread_fn)(unsigned long start, unsigned long end, void *arg); 142 : void *fn_arg; 143 : unsigned long start; 144 : unsigned long size; 145 : unsigned long align; 146 : unsigned long min_chunk; 147 : int max_threads; 148 : }; 149 : 150 : /** 151 : * struct padata_instance - The overall control structure. 152 : * 153 : * @cpu_online_node: Linkage for CPU online callback. 154 : * @cpu_dead_node: Linkage for CPU offline callback. 155 : * @parallel_wq: The workqueue used for parallel work. 156 : * @serial_wq: The workqueue used for serial work. 157 : * @pslist: List of padata_shell objects attached to this instance. 158 : * @cpumask: User supplied cpumasks for parallel and serial works. 159 : * @kobj: padata instance kernel object. 160 : * @lock: padata instance lock. 161 : * @flags: padata flags. 162 : */ 163 : struct padata_instance { 164 : struct hlist_node cpu_online_node; 165 : struct hlist_node cpu_dead_node; 166 : struct workqueue_struct *parallel_wq; 167 : struct workqueue_struct *serial_wq; 168 : struct list_head pslist; 169 : struct padata_cpumask cpumask; 170 : struct kobject kobj; 171 : struct mutex lock; 172 : u8 flags; 173 : #define PADATA_INIT 1 174 : #define PADATA_RESET 2 175 : #define PADATA_INVALID 4 176 : }; 177 : 178 : #ifdef CONFIG_PADATA 179 : extern void __init padata_init(void); 180 : #else 181 1 : static inline void __init padata_init(void) {} 182 : #endif 183 : 184 : extern struct padata_instance *padata_alloc(const char *name); 185 : extern void padata_free(struct padata_instance *pinst); 186 : extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst); 187 : extern void padata_free_shell(struct padata_shell *ps); 188 : extern int padata_do_parallel(struct padata_shell *ps, 189 : struct padata_priv *padata, int *cb_cpu); 190 : extern void padata_do_serial(struct padata_priv *padata); 191 : extern void __init padata_do_multithreaded(struct padata_mt_job *job); 192 : extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, 193 : cpumask_var_t cpumask); 194 : #endif
