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 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 195