xref: /openbmc/linux/include/linux/padata.h (revision 4ec575b7)
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/compiler_types.h>
13 #include <linux/workqueue.h>
14 #include <linux/spinlock.h>
15 #include <linux/list.h>
16 #include <linux/kobject.h>
17 
18 #define PADATA_CPU_SERIAL   0x01
19 #define PADATA_CPU_PARALLEL 0x02
20 
21 /**
22  * struct padata_priv - Represents one job
23  *
24  * @list: List entry, to attach to the padata lists.
25  * @pd: Pointer to the internal control structure.
26  * @cb_cpu: Callback cpu for serializatioon.
27  * @cpu: Cpu for parallelization.
28  * @seq_nr: Sequence number of the parallelized data object.
29  * @info: Used to pass information from the parallel to the serial function.
30  * @parallel: Parallel execution function.
31  * @serial: Serial complete function.
32  */
33 struct padata_priv {
34 	struct list_head	list;
35 	struct parallel_data	*pd;
36 	int			cb_cpu;
37 	int			cpu;
38 	unsigned int		seq_nr;
39 	int			info;
40 	void                    (*parallel)(struct padata_priv *padata);
41 	void                    (*serial)(struct padata_priv *padata);
42 };
43 
44 /**
45  * struct padata_list - one per work type per CPU
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  * @work: work struct for parallelization.
74  * @num_obj: Number of objects that are processed by this cpu.
75  */
76 struct padata_parallel_queue {
77        struct padata_list    parallel;
78        struct padata_list    reorder;
79        struct work_struct    work;
80        atomic_t              num_obj;
81 };
82 
83 /**
84  * struct padata_cpumask - The cpumasks for the parallel/serial workers
85  *
86  * @pcpu: cpumask for the parallel workers.
87  * @cbcpu: cpumask for the serial (callback) workers.
88  */
89 struct padata_cpumask {
90 	cpumask_var_t	pcpu;
91 	cpumask_var_t	cbcpu;
92 };
93 
94 /**
95  * struct parallel_data - Internal control structure, covers everything
96  * that depends on the cpumask in use.
97  *
98  * @ps: padata_shell object.
99  * @pqueue: percpu padata queues used for parallelization.
100  * @squeue: percpu padata queues used for serialuzation.
101  * @refcnt: Number of objects holding a reference on this parallel_data.
102  * @seq_nr: Sequence number of the parallelized data object.
103  * @processed: Number of already processed objects.
104  * @cpu: Next CPU to be processed.
105  * @cpumask: The cpumasks in use for parallel and serial workers.
106  * @reorder_work: work struct for reordering.
107  * @lock: Reorder lock.
108  */
109 struct parallel_data {
110 	struct padata_shell		*ps;
111 	struct padata_parallel_queue	__percpu *pqueue;
112 	struct padata_serial_queue	__percpu *squeue;
113 	atomic_t			refcnt;
114 	atomic_t			seq_nr;
115 	unsigned int			processed;
116 	int				cpu;
117 	struct padata_cpumask		cpumask;
118 	struct work_struct		reorder_work;
119 	spinlock_t                      ____cacheline_aligned lock;
120 };
121 
122 /**
123  * struct padata_shell - Wrapper around struct parallel_data, its
124  * purpose is to allow the underlying control structure to be replaced
125  * on the fly using RCU.
126  *
127  * @pinst: padat instance.
128  * @pd: Actual parallel_data structure which may be substituted on the fly.
129  * @opd: Pointer to old pd to be freed by padata_replace.
130  * @list: List entry in padata_instance list.
131  */
132 struct padata_shell {
133 	struct padata_instance		*pinst;
134 	struct parallel_data __rcu	*pd;
135 	struct parallel_data		*opd;
136 	struct list_head		list;
137 };
138 
139 /**
140  * struct padata_instance - The overall control structure.
141  *
142  * @node: Used by CPU hotplug.
143  * @parallel_wq: The workqueue used for parallel work.
144  * @serial_wq: The workqueue used for serial work.
145  * @pslist: List of padata_shell objects attached to this instance.
146  * @cpumask: User supplied cpumasks for parallel and serial works.
147  * @rcpumask: Actual cpumasks based on user cpumask and cpu_online_mask.
148  * @kobj: padata instance kernel object.
149  * @lock: padata instance lock.
150  * @flags: padata flags.
151  */
152 struct padata_instance {
153 	struct hlist_node		 node;
154 	struct workqueue_struct		*parallel_wq;
155 	struct workqueue_struct		*serial_wq;
156 	struct list_head		pslist;
157 	struct padata_cpumask		cpumask;
158 	struct padata_cpumask		rcpumask;
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(const char *name);
168 extern void padata_free(struct padata_instance *pinst);
169 extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);
170 extern void padata_free_shell(struct padata_shell *ps);
171 extern int padata_do_parallel(struct padata_shell *ps,
172 			      struct padata_priv *padata, int *cb_cpu);
173 extern void padata_do_serial(struct padata_priv *padata);
174 extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
175 			      cpumask_var_t cpumask);
176 extern int padata_start(struct padata_instance *pinst);
177 extern void padata_stop(struct padata_instance *pinst);
178 #endif
179