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 */
45struct 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 */
60struct 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*/
72struct 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 */
91struct 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 */
106struct 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 */
126struct 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 */
153struct 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
167extern struct padata_instance *padata_alloc_possible(
168					struct workqueue_struct *wq);
169extern struct padata_instance *padata_alloc(struct workqueue_struct *wq,
170					    const struct cpumask *pcpumask,
171					    const struct cpumask *cbcpumask);
172extern void padata_free(struct padata_instance *pinst);
173extern int padata_do_parallel(struct padata_instance *pinst,
174			      struct padata_priv *padata, int cb_cpu);
175extern void padata_do_serial(struct padata_priv *padata);
176extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
177			      cpumask_var_t cpumask);
178extern int padata_set_cpumasks(struct padata_instance *pinst,
179			       cpumask_var_t pcpumask,
180			       cpumask_var_t cbcpumask);
181extern int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
182extern int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
183extern int padata_start(struct padata_instance *pinst);
184extern void padata_stop(struct padata_instance *pinst);
185extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
186					    struct notifier_block *nblock);
187extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
188					      struct notifier_block *nblock);
189#endif
190