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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  	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   */
153  struct 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  
167  extern struct padata_instance *padata_alloc_possible(
168  					struct workqueue_struct *wq);
169  extern struct padata_instance *padata_alloc(struct workqueue_struct *wq,
170  					    const struct cpumask *pcpumask,
171  					    const struct cpumask *cbcpumask);
172  extern void padata_free(struct padata_instance *pinst);
173  extern int padata_do_parallel(struct padata_instance *pinst,
174  			      struct padata_priv *padata, int cb_cpu);
175  extern void padata_do_serial(struct padata_priv *padata);
176  extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
177  			      cpumask_var_t cpumask);
178  extern int padata_set_cpumasks(struct padata_instance *pinst,
179  			       cpumask_var_t pcpumask,
180  			       cpumask_var_t cbcpumask);
181  extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
182  extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
183  extern int padata_start(struct padata_instance *pinst);
184  extern void padata_stop(struct padata_instance *pinst);
185  extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
186  					    struct notifier_block *nblock);
187  extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
188  					      struct notifier_block *nblock);
189  #endif
190