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                     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  */
  60 struct 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 */
  72 struct 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  */
  91 struct 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  */
 106 struct 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  */
 126 struct 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         struct padata_cpumask           cpumask;
 133         spinlock_t                      lock ____cacheline_aligned;
 134         spinlock_t                      seq_lock;
 135         unsigned int                    seq_nr;
 136         unsigned int                    processed;
 137         struct timer_list               timer;
 138 };
 139
 140 /**
 141  * struct padata_instance - The overall control structure.
 142  *
 143  * @cpu_notifier: cpu hotplug notifier.
 144  * @wq: The workqueue in use.
 145  * @pd: The internal control structure.
 146  * @cpumask: User supplied cpumasks for parallel and serial works.
 147  * @cpumask_change_notifier: Notifiers chain for user-defined notify
 148  *            callbacks that will be called when either @pcpu or @cbcpu
 149  *            or both cpumasks change.
 150  * @kobj: padata instance kernel object.
 151  * @lock: padata instance lock.
 152  * @flags: padata flags.
 153  */
 154 struct padata_instance {
 155         struct notifier_block            cpu_notifier;
 156         struct workqueue_struct         *wq;
 157         struct parallel_data            *pd;
 158         struct padata_cpumask           cpumask;
 159         struct blocking_notifier_head    cpumask_change_notifier;
 160         struct kobject                   kobj;
 161         struct mutex                     lock;
 162         u8                               flags;
 163 #define PADATA_INIT     1
 164 #define PADATA_RESET    2
 165 #define PADATA_INVALID  4
 166 };
 167
 168 extern struct padata_instance *padata_alloc_possible(
 169                                         struct workqueue_struct *wq);
 170 extern struct padata_instance *padata_alloc(struct workqueue_struct *wq,
 171                                             const struct cpumask *pcpumask,
 172                                             const struct cpumask *cbcpumask);
 173 extern void padata_free(struct padata_instance *pinst);
 174 extern int padata_do_parallel(struct padata_instance *pinst,
 175                               struct padata_priv *padata, int cb_cpu);
 176 extern void padata_do_serial(struct padata_priv *padata);
 177 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 178                               cpumask_var_t cpumask);
 179 extern int padata_set_cpumasks(struct padata_instance *pinst,
 180                                cpumask_var_t pcpumask,
 181                                cpumask_var_t cbcpumask);
 182 extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
 183 extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
 184 extern int padata_start(struct padata_instance *pinst);
 185 extern void padata_stop(struct padata_instance *pinst);
 186 extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
 187                                             struct notifier_block *nblock);
 188 extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
 189                                               struct notifier_block *nblock);
 190 #endif