LXR linux/include/linux/padata.h

   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
   9#ifndef PADATA_H
  10#define PADATA_H
  11
  12#include <linux/workqueue.h>
  13#include <linux/spinlock.h>
  14#include <linux/list.h>
  15#include <linux/notifier.h>
  16#include <linux/kobject.h>
  17
  18#define PADATA_CPU_SERIAL   0x01
  19#define PADATA_CPU_PARALLEL 0x02
  20
  21/**
  22 * struct padata_priv -  Embedded to the users data structure.
  23 *
  24 * @list: List entry, to attach to the padata lists.
  25 * @pd: Pointer to the internal control structure.
  26 * @cb_cpu: Callback cpu for serializatioon.
  27 * @cpu: Cpu for parallelization.
  28 * @seq_nr: Sequence number of the parallelized data object.
  29 * @info: Used to pass information from the parallel to the serial function.
  30 * @parallel: Parallel execution function.
  31 * @serial: Serial complete function.
  32 */
  33struct padata_priv {
  34        struct list_head        list;
  35        struct parallel_data    *pd;
  36        int                     cb_cpu;
  37        int                     cpu;
  38        unsigned int            seq_nr;
  39        int                     info;
  40        void                    (*parallel)(struct padata_priv *padata);
  41        void                    (*serial)(struct padata_priv *padata);
  42};
  43
  44/**
  45 * struct padata_list
  46 *
  47 * @list: List head.
  48 * @lock: List lock.
  49 */
  50struct padata_list {
  51        struct list_head        list;
  52        spinlock_t              lock;
  53};
  54
  55/**
  56* struct padata_serial_queue - The percpu padata serial queue
  57*
  58* @serial: List to wait for serialization after reordering.
  59* @work: work struct for serialization.
  60* @pd: Backpointer to the internal control structure.
  61*/
  62struct padata_serial_queue {
  63       struct padata_list    serial;
  64       struct work_struct    work;
  65       struct parallel_data *pd;
  66};
  67
  68/**
  69 * struct padata_parallel_queue - The percpu padata parallel queue
  70 *
  71 * @parallel: List to wait for parallelization.
  72 * @reorder: List to wait for reordering after parallel processing.
  73 * @serial: List to wait for serialization after reordering.
  74 * @pwork: work struct for parallelization.
  75 * @swork: work struct for serialization.
  76 * @work: work struct for parallelization.
  77 * @num_obj: Number of objects that are processed by this cpu.
  78 */
  79struct padata_parallel_queue {
  80       struct padata_list    parallel;
  81       struct padata_list    reorder;
  82       struct work_struct    work;
  83       atomic_t              num_obj;
  84};
  85
  86/**
  87 * struct padata_cpumask - The cpumasks for the parallel/serial workers
  88 *
  89 * @pcpu: cpumask for the parallel workers.
  90 * @cbcpu: cpumask for the serial (callback) workers.
  91 */
  92struct padata_cpumask {
  93        cpumask_var_t   pcpu;
  94        cpumask_var_t   cbcpu;
  95};
  96
  97/**
  98 * struct parallel_data - Internal control structure, covers everything
  99 * that depends on the cpumask in use.
 100 *
 101 * @pinst: padata instance.
 102 * @pqueue: percpu padata queues used for parallelization.
 103 * @squeue: percpu padata queues used for serialuzation.
 104 * @reorder_objects: Number of objects waiting in the reorder queues.
 105 * @refcnt: Number of objects holding a reference on this parallel_data.
 106 * @max_seq_nr:  Maximal used sequence number.
 107 * @processed: Number of already processed objects.
 108 * @cpu: Next CPU to be processed.
 109 * @cpumask: The cpumasks in use for parallel and serial workers.
 110 * @reorder_work: work struct for reordering.
 111 * @lock: Reorder lock.
 112 */
 113struct parallel_data {
 114        struct padata_instance          *pinst;
 115        struct padata_parallel_queue    __percpu *pqueue;
 116        struct padata_serial_queue      __percpu *squeue;
 117        atomic_t                        reorder_objects;
 118        atomic_t                        refcnt;
 119        atomic_t                        seq_nr;
 120        unsigned int                    processed;
 121        int                             cpu;
 122        struct padata_cpumask           cpumask;
 123        struct work_struct              reorder_work;
 124        spinlock_t                      lock ____cacheline_aligned;
 125};
 126
 127/**
 128 * struct padata_instance - The overall control structure.
 129 *
 130 * @cpu_notifier: cpu hotplug notifier.
 131 * @parallel_wq: The workqueue used for parallel work.
 132 * @serial_wq: The workqueue used for serial work.
 133 * @pd: The internal control structure.
 134 * @cpumask: User supplied cpumasks for parallel and serial works.
 135 * @cpumask_change_notifier: Notifiers chain for user-defined notify
 136 *            callbacks that will be called when either @pcpu or @cbcpu
 137 *            or both cpumasks change.
 138 * @kobj: padata instance kernel object.
 139 * @lock: padata instance lock.
 140 * @flags: padata flags.
 141 */
 142struct padata_instance {
 143        struct hlist_node                node;
 144        struct workqueue_struct         *parallel_wq;
 145        struct workqueue_struct         *serial_wq;
 146        struct parallel_data            *pd;
 147        struct padata_cpumask           cpumask;
 148        struct blocking_notifier_head    cpumask_change_notifier;
 149        struct kobject                   kobj;
 150        struct mutex                     lock;
 151        u8                               flags;
 152#define PADATA_INIT     1
 153#define PADATA_RESET    2
 154#define PADATA_INVALID  4
 155};
 156
 157extern struct padata_instance *padata_alloc_possible(const char *name);
 158extern void padata_free(struct padata_instance *pinst);
 159extern int padata_do_parallel(struct padata_instance *pinst,
 160                              struct padata_priv *padata, int *cb_cpu);
 161extern void padata_do_serial(struct padata_priv *padata);
 162extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 163                              cpumask_var_t cpumask);
 164extern int padata_start(struct padata_instance *pinst);
 165extern void padata_stop(struct padata_instance *pinst);
 166extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
 167                                            struct notifier_block *nblock);
 168extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
 169                                              struct notifier_block *nblock);
 170#endif
 171