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  */
  45 struct padata_priv {
  46         struct list_head        list;
  47         struct parallel_data    *pd;
  48         int                     cb_cpu;
  49         int                     seq_nr;
  50         int                     info;
  51         void                    (*parallel)(struct padata_priv *padata);
  52         void                    (*serial)(struct padata_priv *padata);
  53 };
  54
  55 /**
  56  * struct padata_list
  57  *
  58  * @list: List head.
  59  * @lock: List lock.
  60  */
  61 struct padata_list {
  62         struct list_head        list;
  63         spinlock_t              lock;
  64 };
  65
  66 /**
  67 * struct padata_serial_queue - The percpu padata serial queue
  68 *
  69 * @serial: List to wait for serialization after reordering.
  70 * @work: work struct for serialization.
  71 * @pd: Backpointer to the internal control structure.
  72 */
  73 struct padata_serial_queue {
  74        struct padata_list    serial;
  75        struct work_struct    work;
  76        struct parallel_data *pd;
  77 };
  78
  79 /**
  80  * struct padata_parallel_queue - The percpu padata parallel queue
  81  *
  82  * @parallel: List to wait for parallelization.
  83  * @reorder: List to wait for reordering after parallel processing.
  84  * @serial: List to wait for serialization after reordering.
  85  * @pwork: work struct for parallelization.
  86  * @swork: work struct for serialization.
  87  * @pd: Backpointer to the internal control structure.
  88  * @work: work struct for parallelization.
  89  * @num_obj: Number of objects that are processed by this cpu.
  90  * @cpu_index: Index of the cpu.
  91  */
  92 struct padata_parallel_queue {
  93        struct padata_list    parallel;
  94        struct padata_list    reorder;
  95        struct parallel_data *pd;
  96        struct work_struct    work;
  97        atomic_t              num_obj;
  98        int                   cpu_index;
  99 };
 100
 101 /**
 102  * struct padata_cpumask - The cpumasks for the parallel/serial workers
 103  *
 104  * @pcpu: cpumask for the parallel workers.
 105  * @cbcpu: cpumask for the serial (callback) workers.
 106  */
 107 struct padata_cpumask {
 108         cpumask_var_t   pcpu;
 109         cpumask_var_t   cbcpu;
 110 };
 111
 112 /**
 113  * struct parallel_data - Internal control structure, covers everything
 114  * that depends on the cpumask in use.
 115  *
 116  * @pinst: padata instance.
 117  * @pqueue: percpu padata queues used for parallelization.
 118  * @squeue: percpu padata queues used for serialuzation.
 119  * @seq_nr: The sequence number that will be attached to the next object.
 120  * @reorder_objects: Number of objects waiting in the reorder queues.
 121  * @refcnt: Number of objects holding a reference on this parallel_data.
 122  * @max_seq_nr:  Maximal used sequence number.
 123  * @cpumask: The cpumasks in use for parallel and serial workers.
 124  * @lock: Reorder lock.
 125  * @processed: Number of already processed objects.
 126  * @timer: Reorder timer.
 127  */
 128 struct parallel_data {
 129         struct padata_instance          *pinst;
 130         struct padata_parallel_queue    __percpu *pqueue;
 131         struct padata_serial_queue      __percpu *squeue;
 132         atomic_t                        seq_nr;
 133         atomic_t                        reorder_objects;
 134         atomic_t                        refcnt;
 135         unsigned int                    max_seq_nr;
 136         struct padata_cpumask           cpumask;
 137         spinlock_t                      lock ____cacheline_aligned;
 138         unsigned int                    processed;
 139         struct timer_list               timer;
 140 };
 141
 142 /**
 143  * struct padata_instance - The overall control structure.
 144  *
 145  * @cpu_notifier: cpu hotplug notifier.
 146  * @wq: The workqueue in use.
 147  * @pd: The internal control structure.
 148  * @cpumask: User supplied cpumasks for parallel and serial works.
 149  * @cpumask_change_notifier: Notifiers chain for user-defined notify
 150  *            callbacks that will be called when either @pcpu or @cbcpu
 151  *            or both cpumasks change.
 152  * @kobj: padata instance kernel object.
 153  * @lock: padata instance lock.
 154  * @flags: padata flags.
 155  */
 156 struct padata_instance {
 157         struct notifier_block            cpu_notifier;
 158         struct workqueue_struct         *wq;
 159         struct parallel_data            *pd;
 160         struct padata_cpumask           cpumask;
 161         struct blocking_notifier_head    cpumask_change_notifier;
 162         struct kobject                   kobj;
 163         struct mutex                     lock;
 164         u8                               flags;
 165 #define PADATA_INIT     1
 166 #define PADATA_RESET    2
 167 #define PADATA_INVALID  4
 168 };
 169
 170 extern struct padata_instance *padata_alloc_possible(
 171                                         struct workqueue_struct *wq);
 172 extern struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 173                                             const struct cpumask *pcpumask,
 174                                             const struct cpumask *cbcpumask);
 175 extern void padata_free(struct padata_instance *pinst);
 176 extern int padata_do_parallel(struct padata_instance *pinst,
 177                               struct padata_priv *padata, int cb_cpu);
 178 extern void padata_do_serial(struct padata_priv *padata);
 179 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 180                               cpumask_var_t cpumask);
 181 extern int padata_set_cpumasks(struct padata_instance *pinst,
 182                                cpumask_var_t pcpumask,
 183                                cpumask_var_t cbcpumask);
 184 extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
 185 extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
 186 extern int padata_start(struct padata_instance *pinst);
 187 extern void padata_stop(struct padata_instance *pinst);
 188 extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
 189                                             struct notifier_block *nblock);
 190 extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
 191                                               struct notifier_block *nblock);
 192 #endif