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