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 | * Copyright (c) 2020 Oracle and/or its affiliates. |
9 | * Author: Daniel Jordan <daniel.m.jordan@oracle.com> |
10 | */ |
11 | |
12 | #ifndef PADATA_H |
13 | #define PADATA_H |
14 | |
15 | #include <linux/refcount.h> |
16 | #include <linux/compiler_types.h> |
17 | #include <linux/workqueue.h> |
18 | #include <linux/spinlock.h> |
19 | #include <linux/list.h> |
20 | #include <linux/kobject.h> |
21 | |
22 | #define PADATA_CPU_SERIAL 0x01 |
23 | #define PADATA_CPU_PARALLEL 0x02 |
24 | |
25 | /** |
26 | * struct padata_priv - Represents one job |
27 | * |
28 | * @list: List entry, to attach to the padata lists. |
29 | * @pd: Pointer to the internal control structure. |
30 | * @cb_cpu: Callback cpu for serializatioon. |
31 | * @seq_nr: Sequence number of the parallelized data object. |
32 | * @info: Used to pass information from the parallel to the serial function. |
33 | * @parallel: Parallel execution function. |
34 | * @serial: Serial complete function. |
35 | */ |
36 | struct padata_priv { |
37 | struct list_head list; |
38 | struct parallel_data *pd; |
39 | int cb_cpu; |
40 | unsigned int seq_nr; |
41 | int info; |
42 | void (*parallel)(struct padata_priv *padata); |
43 | void (*serial)(struct padata_priv *padata); |
44 | }; |
45 | |
46 | /** |
47 | * struct padata_list - one per work type per CPU |
48 | * |
49 | * @list: List head. |
50 | * @lock: List lock. |
51 | */ |
52 | struct padata_list { |
53 | struct list_head list; |
54 | spinlock_t lock; |
55 | }; |
56 | |
57 | /** |
58 | * struct padata_serial_queue - The percpu padata serial queue |
59 | * |
60 | * @serial: List to wait for serialization after reordering. |
61 | * @work: work struct for serialization. |
62 | * @pd: Backpointer to the internal control structure. |
63 | */ |
64 | struct padata_serial_queue { |
65 | struct padata_list serial; |
66 | struct work_struct work; |
67 | struct parallel_data *pd; |
68 | }; |
69 | |
70 | /** |
71 | * struct padata_cpumask - The cpumasks for the parallel/serial workers |
72 | * |
73 | * @pcpu: cpumask for the parallel workers. |
74 | * @cbcpu: cpumask for the serial (callback) workers. |
75 | */ |
76 | struct padata_cpumask { |
77 | cpumask_var_t pcpu; |
78 | cpumask_var_t cbcpu; |
79 | }; |
80 | |
81 | /** |
82 | * struct parallel_data - Internal control structure, covers everything |
83 | * that depends on the cpumask in use. |
84 | * |
85 | * @ps: padata_shell object. |
86 | * @reorder_list: percpu reorder lists |
87 | * @squeue: percpu padata queues used for serialuzation. |
88 | * @refcnt: Number of objects holding a reference on this parallel_data. |
89 | * @seq_nr: Sequence number of the parallelized data object. |
90 | * @processed: Number of already processed objects. |
91 | * @cpu: Next CPU to be processed. |
92 | * @cpumask: The cpumasks in use for parallel and serial workers. |
93 | * @reorder_work: work struct for reordering. |
94 | * @lock: Reorder lock. |
95 | */ |
96 | struct parallel_data { |
97 | struct padata_shell *ps; |
98 | struct padata_list __percpu *reorder_list; |
99 | struct padata_serial_queue __percpu *squeue; |
100 | refcount_t refcnt; |
101 | unsigned int seq_nr; |
102 | unsigned int processed; |
103 | int cpu; |
104 | struct padata_cpumask cpumask; |
105 | struct work_struct reorder_work; |
106 | spinlock_t ____cacheline_aligned lock; |
107 | }; |
108 | |
109 | /** |
110 | * struct padata_shell - Wrapper around struct parallel_data, its |
111 | * purpose is to allow the underlying control structure to be replaced |
112 | * on the fly using RCU. |
113 | * |
114 | * @pinst: padat instance. |
115 | * @pd: Actual parallel_data structure which may be substituted on the fly. |
116 | * @opd: Pointer to old pd to be freed by padata_replace. |
117 | * @list: List entry in padata_instance list. |
118 | */ |
119 | struct padata_shell { |
120 | struct padata_instance *pinst; |
121 | struct parallel_data __rcu *pd; |
122 | struct parallel_data *opd; |
123 | struct list_head list; |
124 | }; |
125 | |
126 | /** |
127 | * struct padata_mt_job - represents one multithreaded job |
128 | * |
129 | * @thread_fn: Called for each chunk of work that a padata thread does. |
130 | * @fn_arg: The thread function argument. |
131 | * @start: The start of the job (units are job-specific). |
132 | * @size: size of this node's work (units are job-specific). |
133 | * @align: Ranges passed to the thread function fall on this boundary, with the |
134 | * possible exceptions of the beginning and end of the job. |
135 | * @min_chunk: The minimum chunk size in job-specific units. This allows |
136 | * the client to communicate the minimum amount of work that's |
137 | * appropriate for one worker thread to do at once. |
138 | * @max_threads: Max threads to use for the job, actual number may be less |
139 | * depending on task size and minimum chunk size. |
140 | */ |
141 | struct padata_mt_job { |
142 | void (*thread_fn)(unsigned long start, unsigned long end, void *arg); |
143 | void *fn_arg; |
144 | unsigned long start; |
145 | unsigned long size; |
146 | unsigned long align; |
147 | unsigned long min_chunk; |
148 | int max_threads; |
149 | }; |
150 | |
151 | /** |
152 | * struct padata_instance - The overall control structure. |
153 | * |
154 | * @cpu_online_node: Linkage for CPU online callback. |
155 | * @cpu_dead_node: Linkage for CPU offline callback. |
156 | * @parallel_wq: The workqueue used for parallel work. |
157 | * @serial_wq: The workqueue used for serial work. |
158 | * @pslist: List of padata_shell objects attached to this instance. |
159 | * @cpumask: User supplied cpumasks for parallel and serial works. |
160 | * @kobj: padata instance kernel object. |
161 | * @lock: padata instance lock. |
162 | * @flags: padata flags. |
163 | */ |
164 | struct padata_instance { |
165 | struct hlist_node cpu_online_node; |
166 | struct hlist_node cpu_dead_node; |
167 | struct workqueue_struct *parallel_wq; |
168 | struct workqueue_struct *serial_wq; |
169 | struct list_head pslist; |
170 | struct padata_cpumask cpumask; |
171 | struct kobject kobj; |
172 | struct mutex lock; |
173 | u8 flags; |
174 | #define PADATA_INIT 1 |
175 | #define PADATA_RESET 2 |
176 | #define PADATA_INVALID 4 |
177 | }; |
178 | |
179 | #ifdef CONFIG_PADATA |
180 | extern void __init padata_init(void); |
181 | #else |
182 | static inline void __init padata_init(void) {} |
183 | #endif |
184 | |
185 | extern struct padata_instance *padata_alloc(const char *name); |
186 | extern void padata_free(struct padata_instance *pinst); |
187 | extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst); |
188 | extern void padata_free_shell(struct padata_shell *ps); |
189 | extern int padata_do_parallel(struct padata_shell *ps, |
190 | struct padata_priv *padata, int *cb_cpu); |
191 | extern void padata_do_serial(struct padata_priv *padata); |
192 | extern void __init padata_do_multithreaded(struct padata_mt_job *job); |
193 | extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, |
194 | cpumask_var_t cpumask); |
195 | #endif |
196 | |