xref: /openbmc/linux/include/linux/padata.h (revision 9726bfcd)
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
174