LXR linux/include/linux/padata.h

   1/*
   2 * padata.h - header for the padata parallelization interface
   3 *
   4 * Copyright (C) 2008, 2009 secunet Security Networks AG
   5 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms and conditions of the GNU General Public License,
   9 * version 2, as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope it will be useful, but WITHOUT
  12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14 * more details.
  15 *
  16 * You should have received a copy of the GNU General Public License along with
  17 * this program; if not, write to the Free Software Foundation, Inc.,
  18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21#ifndef PADATA_H
  22#define PADATA_H
  23
  24#include <linux/workqueue.h>
  25#include <linux/spinlock.h>
  26#include <linux/list.h>
  27#include <linux/timer.h>
  28#include <linux/notifier.h>
  29#include <linux/kobject.h>
  30
  31#define PADATA_CPU_SERIAL   0x01
  32#define PADATA_CPU_PARALLEL 0x02
  33
  34/**
  35 * struct padata_priv -  Embedded to the users data structure.
  36 *
  37 * @list: List entry, to attach to the padata lists.
  38 * @pd: Pointer to the internal control structure.
  39 * @cb_cpu: Callback cpu for serializatioon.
  40 * @seq_nr: Sequence number of the parallelized data object.
  41 * @info: Used to pass information from the parallel to the serial function.
  42 * @parallel: Parallel execution function.
  43 * @serial: Serial complete function.
  44 */
  45struct padata_priv {
  46        struct list_head        list;
  47        struct parallel_data    *pd;
  48        int                     cb_cpu;
  49        int                     info;
  50        void                    (*parallel)(struct padata_priv *padata);
  51        void                    (*serial)(struct padata_priv *padata);
  52};
  53
  54/**
  55 * struct padata_list
  56 *
  57 * @list: List head.
  58 * @lock: List lock.
  59 */
  60struct padata_list {
  61        struct list_head        list;
  62        spinlock_t              lock;
  63};
  64
  65/**
  66* struct padata_serial_queue - The percpu padata serial queue
  67*
  68* @serial: List to wait for serialization after reordering.
  69* @work: work struct for serialization.
  70* @pd: Backpointer to the internal control structure.
  71*/
  72struct padata_serial_queue {
  73       struct padata_list    serial;
  74       struct work_struct    work;
  75       struct parallel_data *pd;
  76};
  77
  78/**
  79 * struct padata_parallel_queue - The percpu padata parallel queue
  80 *
  81 * @parallel: List to wait for parallelization.
  82 * @reorder: List to wait for reordering after parallel processing.
  83 * @serial: List to wait for serialization after reordering.
  84 * @pwork: work struct for parallelization.
  85 * @swork: work struct for serialization.
  86 * @pd: Backpointer to the internal control structure.
  87 * @work: work struct for parallelization.
  88 * @num_obj: Number of objects that are processed by this cpu.
  89 * @cpu_index: Index of the cpu.
  90 */
  91struct padata_parallel_queue {
  92       struct padata_list    parallel;
  93       struct padata_list    reorder;
  94       struct parallel_data *pd;
  95       struct work_struct    work;
  96       atomic_t              num_obj;
  97       int                   cpu_index;
  98};
  99
 100/**
 101 * struct padata_cpumask - The cpumasks for the parallel/serial workers
 102 *
 103 * @pcpu: cpumask for the parallel workers.
 104 * @cbcpu: cpumask for the serial (callback) workers.
 105 */
 106struct padata_cpumask {
 107        cpumask_var_t   pcpu;
 108        cpumask_var_t   cbcpu;
 109};
 110
 111/**
 112 * struct parallel_data - Internal control structure, covers everything
 113 * that depends on the cpumask in use.
 114 *
 115 * @pinst: padata instance.
 116 * @pqueue: percpu padata queues used for parallelization.
 117 * @squeue: percpu padata queues used for serialuzation.
 118 * @reorder_objects: Number of objects waiting in the reorder queues.
 119 * @refcnt: Number of objects holding a reference on this parallel_data.
 120 * @max_seq_nr:  Maximal used sequence number.
 121 * @cpumask: The cpumasks in use for parallel and serial workers.
 122 * @lock: Reorder lock.
 123 * @processed: Number of already processed objects.
 124 * @timer: Reorder timer.
 125 */
 126struct parallel_data {
 127        struct padata_instance          *pinst;
 128        struct padata_parallel_queue    __percpu *pqueue;
 129        struct padata_serial_queue      __percpu *squeue;
 130        atomic_t                        reorder_objects;
 131        atomic_t                        refcnt;
 132        atomic_t                        seq_nr;
 133        struct padata_cpumask           cpumask;
 134        spinlock_t                      lock ____cacheline_aligned;
 135        unsigned int                    processed;
 136        struct timer_list               timer;
 137};
 138
 139/**
 140 * struct padata_instance - The overall control structure.
 141 *
 142 * @cpu_notifier: cpu hotplug notifier.
 143 * @wq: The workqueue in use.
 144 * @pd: The internal control structure.
 145 * @cpumask: User supplied cpumasks for parallel and serial works.
 146 * @cpumask_change_notifier: Notifiers chain for user-defined notify
 147 *            callbacks that will be called when either @pcpu or @cbcpu
 148 *            or both cpumasks change.
 149 * @kobj: padata instance kernel object.
 150 * @lock: padata instance lock.
 151 * @flags: padata flags.
 152 */
 153struct padata_instance {
 154        struct notifier_block            cpu_notifier;
 155        struct workqueue_struct         *wq;
 156        struct parallel_data            *pd;
 157        struct padata_cpumask           cpumask;
 158        struct blocking_notifier_head    cpumask_change_notifier;
 159        struct kobject                   kobj;
 160        struct mutex                     lock;
 161        u8                               flags;
 162#define PADATA_INIT     1
 163#define PADATA_RESET    2
 164#define PADATA_INVALID  4
 165};
 166
 167extern struct padata_instance *padata_alloc_possible(
 168                                        struct workqueue_struct *wq);
 169extern struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 170                                            const struct cpumask *pcpumask,
 171                                            const struct cpumask *cbcpumask);
 172extern void padata_free(struct padata_instance *pinst);
 173extern int padata_do_parallel(struct padata_instance *pinst,
 174                              struct padata_priv *padata, int cb_cpu);
 175extern void padata_do_serial(struct padata_priv *padata);
 176extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 177                              cpumask_var_t cpumask);
 178extern int padata_set_cpumasks(struct padata_instance *pinst,
 179                               cpumask_var_t pcpumask,
 180                               cpumask_var_t cbcpumask);
 181extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
 182extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
 183extern int padata_start(struct padata_instance *pinst);
 184extern void padata_stop(struct padata_instance *pinst);
 185extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
 186                                            struct notifier_block *nblock);
 187extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
 188                                              struct notifier_block *nblock);
 189#endif
 190