xref: /openbmc/linux/include/linux/padata.h (revision 4f3db074)
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