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/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 0x01 23 #define PADATA_CPU_PARALLEL 0x02 24 25 /** 26 * struct padata_priv - Represents one job 27 * 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 */ 36 struct 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 CPU 48 * 49 * @list: List head. 50 * @lock: List lock. 51 */ 52 struct padata_list { 53 struct list_head list; 54 spinlock_t lock; 55 }; 56 57 /** 58 * struct padata_serial_queue - The percpu padata serial queue 59 * 60 * @serial: List to wait for serialization after reordering. 61 * @work: work struct for serialization. 62 * @pd: Backpointer to the internal control structure. 63 */ 64 struct 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 workers 72 * 73 * @pcpu: cpumask for the parallel workers. 74 * @cbcpu: cpumask for the serial (callback) workers. 75 */ 76 struct padata_cpumask { 77 cpumask_var_t pcpu; 78 cpumask_var_t cbcpu; 79 }; 80 81 /** 82 * struct parallel_data - Internal control structure, covers everything 83 * that depends on the cpumask in use. 84 * 85 * @ps: padata_shell object. 86 * @reorder_list: percpu reorder lists 87 * @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 */ 96 struct 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, its 111 * purpose is to allow the underlying control structure to be replaced 112 * 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 */ 119 struct 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 job 128 * 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 the 134 * possible exceptions of the beginning and end of the job. 135 * @min_chunk: The minimum chunk size in job-specific units. This allows 136 * the client to communicate the minimum amount of work that's 137 * appropriate for one worker thread to do at once. 138 * @max_threads: Max threads to use for the job, actual number may be less 139 * depending on task size and minimum chunk size. 140 * @numa_aware: Distribute jobs to different nodes with CPU in a round robin fashion. 141 */ 142 struct 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 */ 166 struct 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 1 177 #define PADATA_RESET 2 178 #define PADATA_INVALID 4 179 }; 180 181 #ifdef CONFIG_PADATA 182 extern void __init padata_init(void); 183 extern struct padata_instance *padata_alloc(const char *name); 184 extern void padata_free(struct padata_instance *pinst); 185 extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst); 186 extern void padata_free_shell(struct padata_shell *ps); 187 extern int padata_do_parallel(struct padata_shell *ps, 188 struct padata_priv *padata, int *cb_cpu); 189 extern void padata_do_serial(struct padata_priv *padata); 190 extern void __init padata_do_multithreaded(struct padata_mt_job *job); 191 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, 192 cpumask_var_t cpumask); 193 #else padata_init(void)194 static inline void __init padata_init(void) {} padata_do_multithreaded(struct padata_mt_job * job)195 static 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 #endif 200 201 #endif 202