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