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      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