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
66typedef 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
79void pcu_switchpoint(lwp_t *);
80void pcu_discard_all(lwp_t *);
81void pcu_save_all(lwp_t *);
82
83void pcu_load(const pcu_ops_t *);
84void pcu_save(const pcu_ops_t *, lwp_t *);
85void pcu_save_all_on_cpu(void);
86void pcu_discard(const pcu_ops_t *, lwp_t *, bool);
87bool pcu_valid_p(const pcu_ops_t *, const lwp_t *);
88
89/* PCU operations structure provided by the MD code. */
90extern 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