[linux-block.git] / include / linux / padata.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * padata.h - header for the padata parallelization interface
 *
 * Copyright (C) 2008, 2009 secunet Security Networks AG
 * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
 *
 * Copyright (c) 2020 Oracle and/or its affiliates.
 * Author: Daniel Jordan <daniel.m.jordan@oracle.com>
 */

#ifndef PADATA_H
#define PADATA_H

#include <linux/refcount.h>
#include <linux/compiler_types.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/kobject.h>

#define PADATA_CPU_SERIAL   0x01
#define PADATA_CPU_PARALLEL 0x02

/**
 * struct padata_priv - Represents one job
 *
 * @list: List entry, to attach to the padata lists.
 * @pd: Pointer to the internal control structure.
 * @cb_cpu: Callback cpu for serializatioon.
 * @seq_nr: Sequence number of the parallelized data object.
 * @info: Used to pass information from the parallel to the serial function.
 * @parallel: Parallel execution function.
 * @serial: Serial complete function.
 */
struct padata_priv {
	struct list_head	list;
	struct parallel_data	*pd;
	int			cb_cpu;
	unsigned int		seq_nr;
	int			info;
	void                    (*parallel)(struct padata_priv *padata);
	void                    (*serial)(struct padata_priv *padata);
};

/**
 * struct padata_list - one per work type per CPU
 *
 * @list: List head.
 * @lock: List lock.
 */
struct padata_list {
	struct list_head        list;
	spinlock_t              lock;
};

/**
* struct padata_serial_queue - The percpu padata serial queue
*
* @serial: List to wait for serialization after reordering.
* @work: work struct for serialization.
* @pd: Backpointer to the internal control structure.
*/
struct padata_serial_queue {
       struct padata_list    serial;
       struct work_struct    work;
       struct parallel_data *pd;
};

/**
 * struct padata_cpumask - The cpumasks for the parallel/serial workers
 *
 * @pcpu: cpumask for the parallel workers.
 * @cbcpu: cpumask for the serial (callback) workers.
 */
struct padata_cpumask {
	cpumask_var_t	pcpu;
	cpumask_var_t	cbcpu;
};

/**
 * struct parallel_data - Internal control structure, covers everything
 * that depends on the cpumask in use.
 *
 * @ps: padata_shell object.
 * @reorder_list: percpu reorder lists
 * @squeue: percpu padata queues used for serialuzation.
 * @refcnt: Number of objects holding a reference on this parallel_data.
 * @seq_nr: Sequence number of the parallelized data object.
 * @processed: Number of already processed objects.
 * @cpu: Next CPU to be processed.
 * @cpumask: The cpumasks in use for parallel and serial workers.
 * @reorder_work: work struct for reordering.
 * @lock: Reorder lock.
 */
struct parallel_data {
	struct padata_shell		*ps;
	struct padata_list		__percpu *reorder_list;
	struct padata_serial_queue	__percpu *squeue;
	refcount_t			refcnt;
	unsigned int			seq_nr;
	unsigned int			processed;
	int				cpu;
	struct padata_cpumask		cpumask;
	struct work_struct		reorder_work;
	spinlock_t                      ____cacheline_aligned lock;
};

/**
 * struct padata_shell - Wrapper around struct parallel_data, its
 * purpose is to allow the underlying control structure to be replaced
 * on the fly using RCU.
 *
 * @pinst: padat instance.
 * @pd: Actual parallel_data structure which may be substituted on the fly.
 * @opd: Pointer to old pd to be freed by padata_replace.
 * @list: List entry in padata_instance list.
 */
struct padata_shell {
	struct padata_instance		*pinst;
	struct parallel_data __rcu	*pd;
	struct parallel_data		*opd;
	struct list_head		list;
};

/**
 * struct padata_mt_job - represents one multithreaded job
 *
 * @thread_fn: Called for each chunk of work that a padata thread does.
 * @fn_arg: The thread function argument.
 * @start: The start of the job (units are job-specific).
 * @size: size of this node's work (units are job-specific).
 * @align: Ranges passed to the thread function fall on this boundary, with the
 *         possible exceptions of the beginning and end of the job.
 * @min_chunk: The minimum chunk size in job-specific units.  This allows
 *             the client to communicate the minimum amount of work that's
 *             appropriate for one worker thread to do at once.
 * @max_threads: Max threads to use for the job, actual number may be less
 *               depending on task size and minimum chunk size.
 * @numa_aware: Distribute jobs to different nodes with CPU in a round robin fashion.
 */
struct padata_mt_job {
	void (*thread_fn)(unsigned long start, unsigned long end, void *arg);
	void			*fn_arg;
	unsigned long		start;
	unsigned long		size;
	unsigned long		align;
	unsigned long		min_chunk;
	int			max_threads;
	bool			numa_aware;
};

/**
 * struct padata_instance - The overall control structure.
 *
 * @cpu_online_node: Linkage for CPU online callback.
 * @cpu_dead_node: Linkage for CPU offline callback.
 * @parallel_wq: The workqueue used for parallel work.
 * @serial_wq: The workqueue used for serial work.
 * @pslist: List of padata_shell objects attached to this instance.
 * @cpumask: User supplied cpumasks for parallel and serial works.
 * @kobj: padata instance kernel object.
 * @lock: padata instance lock.
 * @flags: padata flags.
 */
struct padata_instance {
	struct hlist_node		cpu_online_node;
	struct hlist_node		cpu_dead_node;
	struct workqueue_struct		*parallel_wq;
	struct workqueue_struct		*serial_wq;
	struct list_head		pslist;
	struct padata_cpumask		cpumask;
	struct kobject                   kobj;
	struct mutex			 lock;
	u8				 flags;
#define	PADATA_INIT	1
#define	PADATA_RESET	2
#define	PADATA_INVALID	4
};

#ifdef CONFIG_PADATA
extern void __init padata_init(void);
extern struct padata_instance *padata_alloc(const char *name);
extern void padata_free(struct padata_instance *pinst);
extern struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);
extern void padata_free_shell(struct padata_shell *ps);
extern int padata_do_parallel(struct padata_shell *ps,
			      struct padata_priv *padata, int *cb_cpu);
extern void padata_do_serial(struct padata_priv *padata);
extern void __init padata_do_multithreaded(struct padata_mt_job *job);
extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
			      cpumask_var_t cpumask);
#else
static inline void __init padata_init(void) {}
static inline void __init padata_do_multithreaded(struct padata_mt_job *job)
{
	job->thread_fn(job->start, job->start + job->size, job->fn_arg);
}
#endif

#endif
Commit	Line	Data
	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	* @numa_aware: Distribute jobs to different nodes with CPU in a round robin fashion.
	141	*/
	142	struct padata_mt_job {
	143	void (thread_fn)(unsigned long start, unsigned long end, void arg);
	144	void *fn_arg;
	145	unsigned long start;
	146	unsigned long size;
	147	unsigned long align;
	148	unsigned long min_chunk;
	149	int max_threads;
	150	bool numa_aware;
	151	};
	152
	153	/**
	154	* struct padata_instance - The overall control structure.
	155	*
	156	* @cpu_online_node: Linkage for CPU online callback.
	157	* @cpu_dead_node: Linkage for CPU offline callback.
	158	* @parallel_wq: The workqueue used for parallel work.
	159	* @serial_wq: The workqueue used for serial work.
	160	* @pslist: List of padata_shell objects attached to this instance.
	161	* @cpumask: User supplied cpumasks for parallel and serial works.
	162	* @kobj: padata instance kernel object.
	163	* @lock: padata instance lock.
	164	* @flags: padata flags.
	165	*/
	166	struct padata_instance {
	167	struct hlist_node cpu_online_node;
	168	struct hlist_node cpu_dead_node;
	169	struct workqueue_struct *parallel_wq;
	170	struct workqueue_struct *serial_wq;
	171	struct list_head pslist;
	172	struct padata_cpumask cpumask;
	173	struct kobject kobj;
	174	struct mutex lock;
	175	u8 flags;
	176	#define PADATA_INIT 1
	177	#define PADATA_RESET 2
	178	#define PADATA_INVALID 4
	179	};
	180
	181	#ifdef CONFIG_PADATA
	182	extern void __init padata_init(void);
	183	extern struct padata_instance padata_alloc(const char name);
	184	extern void padata_free(struct padata_instance *pinst);
	185	extern struct padata_shell padata_alloc_shell(struct padata_instance pinst);
	186	extern void padata_free_shell(struct padata_shell *ps);
	187	extern int padata_do_parallel(struct padata_shell *ps,
	188	struct padata_priv padata, int cb_cpu);
	189	extern void padata_do_serial(struct padata_priv *padata);
	190	extern void __init padata_do_multithreaded(struct padata_mt_job *job);
	191	extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
	192	cpumask_var_t cpumask);
	193	#else
	194	static inline void __init padata_init(void) {}
	195	static inline void __init padata_do_multithreaded(struct padata_mt_job *job)
	196	{
	197	job->thread_fn(job->start, job->start + job->size, job->fn_arg);
	198	}
	199	#endif
	200
	201	#endif