freebsd-dev/sys/alpha/include/mutex.h

116 lines
3.5 KiB
C
Raw Normal View History

/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
* $FreeBSD$
*/
#ifndef _MACHINE_MUTEX_H_
#define _MACHINE_MUTEX_H_
#ifndef LOCORE
2000-10-04 01:21:58 +00:00
#ifdef _KERNEL
/*
* Debugging
*/
- Make the mutex code almost completely machine independent. This greatly reducues the maintenance load for the mutex code. The only MD portions of the mutex code are in machine/mutex.h now, which include the assembly macros for handling mutexes as well as optionally overriding the mutex micro-operations. For example, we use optimized micro-ops on the x86 platform #ifndef I386_CPU. - Change the behavior of the SMP_DEBUG kernel option. In the new code, mtx_assert() only depends on INVARIANTS, allowing other kernel developers to have working mutex assertiions without having to include all of the mutex debugging code. The SMP_DEBUG kernel option has been renamed to MUTEX_DEBUG and now just controls extra mutex debugging code. - Abolish the ugly mtx_f hack. Instead, we dynamically allocate seperate mtx_debug structures on the fly in mtx_init, except for mutexes that are initiated very early in the boot process. These mutexes are declared using a special MUTEX_DECLARE() macro, and use a new flag MTX_COLD when calling mtx_init. This is still somewhat hackish, but it is less evil than the mtx_f filler struct, and the mtx struct is now the same size with and without mutex debugging code. - Add some micro-micro-operation macros for doing the actual atomic operations on the mutex mtx_lock field to make it easier for other archs to override/optimize mutex ops if needed. These new tiny ops also clean up the code in some places by replacing long atomic operation function calls that spanned 2-3 lines with a short 1-line macro call. - Don't call mi_switch() from mtx_enter_hard() when we block while trying to obtain a sleep mutex. Calling mi_switch() would bogusly release Giant before switching to the next process. Instead, inline most of the code from mi_switch() in the mtx_enter_hard() function. Note that when we finally kill Giant we can back this out and go back to calling mi_switch().
2000-10-20 07:26:37 +00:00
#ifdef MUTEX_DEBUG
- Make the mutex code almost completely machine independent. This greatly reducues the maintenance load for the mutex code. The only MD portions of the mutex code are in machine/mutex.h now, which include the assembly macros for handling mutexes as well as optionally overriding the mutex micro-operations. For example, we use optimized micro-ops on the x86 platform #ifndef I386_CPU. - Change the behavior of the SMP_DEBUG kernel option. In the new code, mtx_assert() only depends on INVARIANTS, allowing other kernel developers to have working mutex assertiions without having to include all of the mutex debugging code. The SMP_DEBUG kernel option has been renamed to MUTEX_DEBUG and now just controls extra mutex debugging code. - Abolish the ugly mtx_f hack. Instead, we dynamically allocate seperate mtx_debug structures on the fly in mtx_init, except for mutexes that are initiated very early in the boot process. These mutexes are declared using a special MUTEX_DECLARE() macro, and use a new flag MTX_COLD when calling mtx_init. This is still somewhat hackish, but it is less evil than the mtx_f filler struct, and the mtx struct is now the same size with and without mutex debugging code. - Add some micro-micro-operation macros for doing the actual atomic operations on the mutex mtx_lock field to make it easier for other archs to override/optimize mutex ops if needed. These new tiny ops also clean up the code in some places by replacing long atomic operation function calls that spanned 2-3 lines with a short 1-line macro call. - Don't call mi_switch() from mtx_enter_hard() when we block while trying to obtain a sleep mutex. Calling mi_switch() would bogusly release Giant before switching to the next process. Instead, inline most of the code from mi_switch() in the mtx_enter_hard() function. Note that when we finally kill Giant we can back this out and go back to calling mi_switch().
2000-10-20 07:26:37 +00:00
#ifdef _KERN_MUTEX_C_
char STR_IEN[] = "ps & IPL != IPL_HIGH";
char STR_IDIS[] = "ps & IPL == IPL_HIGH";
char STR_SIEN[] = "mpp->mtx_saveintr != IPL_HIGH";
#else /* _KERN_MUTEX_C_ */
extern char STR_IEN[];
extern char STR_IDIS[];
- Make the mutex code almost completely machine independent. This greatly reducues the maintenance load for the mutex code. The only MD portions of the mutex code are in machine/mutex.h now, which include the assembly macros for handling mutexes as well as optionally overriding the mutex micro-operations. For example, we use optimized micro-ops on the x86 platform #ifndef I386_CPU. - Change the behavior of the SMP_DEBUG kernel option. In the new code, mtx_assert() only depends on INVARIANTS, allowing other kernel developers to have working mutex assertiions without having to include all of the mutex debugging code. The SMP_DEBUG kernel option has been renamed to MUTEX_DEBUG and now just controls extra mutex debugging code. - Abolish the ugly mtx_f hack. Instead, we dynamically allocate seperate mtx_debug structures on the fly in mtx_init, except for mutexes that are initiated very early in the boot process. These mutexes are declared using a special MUTEX_DECLARE() macro, and use a new flag MTX_COLD when calling mtx_init. This is still somewhat hackish, but it is less evil than the mtx_f filler struct, and the mtx struct is now the same size with and without mutex debugging code. - Add some micro-micro-operation macros for doing the actual atomic operations on the mutex mtx_lock field to make it easier for other archs to override/optimize mutex ops if needed. These new tiny ops also clean up the code in some places by replacing long atomic operation function calls that spanned 2-3 lines with a short 1-line macro call. - Don't call mi_switch() from mtx_enter_hard() when we block while trying to obtain a sleep mutex. Calling mi_switch() would bogusly release Giant before switching to the next process. Instead, inline most of the code from mi_switch() in the mtx_enter_hard() function. Note that when we finally kill Giant we can back this out and go back to calling mi_switch().
2000-10-20 07:26:37 +00:00
extern char STR_SIEN[];
#endif /* _KERN_MUTEX_C_ */
#endif /* MUTEX_DEBUG */
#define ASS_IEN MPASS2((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK) \
== ALPHA_PSL_IPL_HIGH, STR_IEN)
#define ASS_IDIS MPASS2((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK) \
!= ALPHA_PSL_IPL_HIGH, STR_IDIS)
#define ASS_SIEN(mpp) MPASS2((mpp)->mtx_saveintr \
!= ALPHA_PSL_IPL_HIGH, STR_SIEN)
#define mtx_legal2block() \
((alpha_pal_rdps() & ALPHA_PSL_IPL_MASK) == ALPHA_PSL_IPL_HIGH)
/*
* Assembly macros (for internal use only)
*--------------------------------------------------------------------------
*/
#define _V(x) __STRING(x)
/*
* Get a spin lock, handle recusion inline (as the less common case)
*/
#define _getlock_spin_block(mp, tid, type) do { \
u_int _ipl = alpha_pal_swpipl(ALPHA_PSL_IPL_HIGH); \
if (!_obtain_lock(mp, tid)) \
mtx_enter_hard(mp, (type) & MTX_HARDOPTS, _ipl); \
else { \
alpha_mb(); \
(mp)->mtx_saveintr = _ipl; \
} \
} while (0)
#endif /* _KERNEL */
#else /* !LOCORE */
/*
* Simple assembly macros to get and release non-recursive spin locks
*/
#define MTX_ENTER(lck) \
ldiq a0, ALPHA_PSL_IPL_HIGH; \
call_pal PAL_OSF1_swpipl; \
1: ldq_l a0, lck+MTX_LOCK; \
cmpeq a0, MTX_UNOWNED, a1; \
beq a1, 1b; \
ldq a0, PC_CURPROC(globalp); \
stq_c a0, lck+MTX_LOCK; \
beq a0, 1b; \
mb; \
stl v0, lck+MTX_SAVEINTR
#define MTX_EXIT(lck) \
mb; \
ldiq a0, MTX_UNOWNED; \
stq a0, lck+MTX_LOCK; \
ldl a0, lck+MTX_SAVEINTR; \
call_pal PAL_OSF1_swpipl
#endif /* !LOCORE */
#endif /* __MACHINE_MUTEX_H */