xref: /netbsd/sys/sys/pcu.h (revision 6e07cca1)
1 /*	$NetBSD: pcu.h,v 1.14 2022/10/26 23:38:58 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Mindaugas Rasiukevicius.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_PCU_H_
33 #define _SYS_PCU_H_
34 
35 #if !defined(_KERNEL) && !defined(_KMEMUSER)
36 #error "not supposed to be exposed to userland"
37 #endif
38 
39 #ifndef _KERNEL
40 #include <stdbool.h>
41 #endif
42 
43 /*
44  * Default: no PCU for MD.
45  */
46 #ifndef	PCU_UNIT_COUNT
47 #define	PCU_UNIT_COUNT		0
48 #endif
49 
50 #if PCU_UNIT_COUNT > 0
51 
52 /*
53  * pcu_state_save(lwp)
54  *	Tells MD code to save the current CPU's state into the given
55  *	LWP's MD storage.
56  *
57  * pcu_state_load(lwp, flags)
58  *	Tells MD code to load PCU state from the given LWP's MD storage
59  *	to the current CPU.
60  *
61  * pcu_state_release(lwp)
62  *	Tells MD code detect the next use of the PCU on the LWP and
63  *	call pcu_load().
64  */
65 
66 typedef struct {
67 	u_int	pcu_id;
68 	void	(*pcu_state_save)(lwp_t *);
69 	void	(*pcu_state_load)(lwp_t *, unsigned);
70 	void	(*pcu_state_release)(lwp_t *);
71 } pcu_ops_t;
72 
73 /*
74  * Flags for the pcu_state_load() operation.
75  */
76 #define	PCU_VALID	0x01	/* PCU state is considered valid */
77 #define	PCU_REENABLE	0x02	/* the state is present, re-enable PCU */
78 
79 void	pcu_switchpoint(lwp_t *);
80 void	pcu_discard_all(lwp_t *);
81 void	pcu_save_all(lwp_t *);
82 
83 void	pcu_load(const pcu_ops_t *);
84 void	pcu_save(const pcu_ops_t *, lwp_t *);
85 void	pcu_save_all_on_cpu(void);
86 void	pcu_discard(const pcu_ops_t *, lwp_t *, bool);
87 bool	pcu_valid_p(const pcu_ops_t *, const lwp_t *);
88 
89 /* PCU operations structure provided by the MD code. */
90 extern const pcu_ops_t *const pcu_ops_md_defs[];
91 
92 #else
93 #define	pcu_switchpoint(l)
94 #define	pcu_discard_all(l)
95 #define	pcu_save_all(l)
96 #endif
97 
98 #endif
99