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freebsd/sys/amd64/include/mutex.h
John Baldwin 18f619abce Fix the assembly mutex macros to call the appropriate witness functions if
the witness code is compiled in.  Without this, the witness code doesn't
notice that sched_lock is released by fork_trampoline() and thus gets all
confused about spin lock order later on.
2000-12-12 03:49:58 +00:00

368 lines
10 KiB
C

/*-
* 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
#ifdef _KERNEL
#include <machine/psl.h>
/* Global locks */
extern struct mtx clock_lock;
/*
* Debugging
*/
#ifdef MUTEX_DEBUG
#ifdef _KERN_MUTEX_C_
char STR_IEN[] = "fl & PSL_I";
char STR_IDIS[] = "!(fl & PSL_I)";
char STR_SIEN[] = "mpp->mtx_saveintr & PSL_I";
#else /* _KERN_MUTEX_C_ */
extern char STR_IEN[];
extern char STR_IDIS[];
extern char STR_SIEN[];
#endif /* _KERN_MUTEX_C_ */
#endif /* MUTEX_DEBUG */
#define ASS_IEN MPASS2(read_eflags() & PSL_I, STR_IEN)
#define ASS_IDIS MPASS2((read_eflags() & PSL_I) == 0, STR_IDIS)
#define ASS_SIEN(mpp) MPASS2((mpp)->mtx_saveintr & PSL_I, STR_SIEN)
#define mtx_legal2block() (read_eflags() & PSL_I)
/*
* Assembly macros (for internal use only)
*------------------------------------------------------------------------------
*/
#define _V(x) __STRING(x)
#if 0
/* #ifndef I386_CPU */
/*
* For 486 and newer processors.
*/
/* Get a sleep lock, deal with recursion inline. */
#define _getlock_sleep(mtxp, tid, type) ({ \
int _res; \
\
__asm __volatile ( \
" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
" " MPLOCKED "" \
" cmpxchgl %3,%1;" /* Try */ \
" jz 1f;" /* Got it */ \
" andl $" _V(MTX_FLAGMASK) ",%%eax;" /* turn off spec bits */ \
" cmpl %%eax,%3;" /* already have it? */ \
" je 2f;" /* yes, recurse */ \
" pushl %4;" \
" pushl %5;" \
" call mtx_enter_hard;" \
" addl $8,%%esp;" \
" jmp 1f;" \
"2:" \
" " MPLOCKED "" \
" orl $" _V(MTX_RECURSE) ",%1;" \
" incl %2;" \
"1:" \
"# getlock_sleep" \
: "=&a" (_res), /* 0 (dummy output) */ \
"+m" (mtxp->mtx_lock), /* 1 */ \
"+m" (mtxp->mtx_recurse) /* 2 */ \
: "r" (tid), /* 3 (input) */ \
"gi" (type), /* 4 */ \
"g" (mtxp) /* 5 */ \
: "memory", "ecx", "edx" /* used */ ); \
})
/* Get a spin lock, handle recursion inline (as the less common case) */
#define _getlock_spin_block(mtxp, tid, type) ({ \
int _res; \
\
__asm __volatile ( \
" pushfl;" \
" cli;" \
" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
" " MPLOCKED "" \
" cmpxchgl %3,%1;" /* Try */ \
" jz 2f;" /* got it */ \
" pushl %4;" \
" pushl %5;" \
" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type, oflags) */ \
" addl $12,%%esp;" \
" jmp 1f;" \
"2: popl %2;" /* save flags */ \
"1:" \
"# getlock_spin_block" \
: "=&a" (_res), /* 0 (dummy output) */ \
"+m" (mtxp->mtx_lock), /* 1 */ \
"=m" (mtxp->mtx_saveintr) /* 2 */ \
: "r" (tid), /* 3 (input) */ \
"gi" (type), /* 4 */ \
"g" (mtxp) /* 5 */ \
: "memory", "ecx", "edx" /* used */ ); \
})
/*
* Get a lock without any recursion handling. Calls the hard enter function if
* we can't get it inline.
*/
#define _getlock_norecurse(mtxp, tid, type) ({ \
int _res; \
\
__asm __volatile ( \
" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
" " MPLOCKED "" \
" cmpxchgl %2,%1;" /* Try */ \
" jz 1f;" /* got it */ \
" pushl %3;" \
" pushl %4;" \
" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type) */ \
" addl $8,%%esp;" \
"1:" \
"# getlock_norecurse" \
: "=&a" (_res), /* 0 (dummy output) */ \
"+m" (mtxp->mtx_lock) /* 1 */ \
: "r" (tid), /* 2 (input) */ \
"gi" (type), /* 3 */ \
"g" (mtxp) /* 4 */ \
: "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a sleep lock assuming we haven't recursed on it, recursion is handled
* in the hard function.
*/
#define _exitlock_norecurse(mtxp, tid, type) ({ \
int _tid = (int)(tid); \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %4,%0;" /* try easy rel */ \
" jz 1f;" /* released! */ \
" pushl %2;" \
" pushl %3;" \
" call mtx_exit_hard;" \
" addl $8,%%esp;" \
"1:" \
"# exitlock_norecurse" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+a" (_tid) /* 1 */ \
: "gi" (type), /* 2 (input) */ \
"g" (mtxp), /* 3 */ \
"r" (MTX_UNOWNED) /* 4 */ \
: "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a sleep lock when its likely we recursed (the code to
* deal with simple recursion is inline).
*/
#define _exitlock(mtxp, tid, type) ({ \
int _tid = (int)(tid); \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %5,%0;" /* try easy rel */ \
" jz 1f;" /* released! */ \
" testl $" _V(MTX_RECURSE) ",%%eax;" /* recursed? */ \
" jnz 3f;" /* handle recursion */ \
/* Lock not recursed and contested: do the hard way */ \
" pushl %3;" \
" pushl %4;" \
" call mtx_exit_hard;" /* mtx_exit_hard(mtxp,type) */ \
" addl $8,%%esp;" \
" jmp 1f;" \
/* lock recursed, lower recursion level */ \
"3: decl %1;" /* one less level */ \
" jnz 1f;" /* still recursed, done */ \
" lock; andl $~" _V(MTX_RECURSE) ",%0;" /* turn off recurse flag */ \
"1:" \
"# exitlock" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+m" (mtxp->mtx_recurse), /* 1 */ \
"+a" (_tid) /* 2 */ \
: "gi" (type), /* 3 (input) */ \
"g" (mtxp), /* 4 */ \
"r" (MTX_UNOWNED) /* 5 */ \
: "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a spin lock (with possible recursion).
*
* We use cmpxchgl to clear lock (instead of simple store) to flush posting
* buffers and make the change visible to other CPU's.
*/
#define _exitlock_spin(mtxp) ({ \
int _res; \
\
__asm __volatile ( \
" movl %1,%2;" \
" decl %2;" \
" js 1f;" \
" movl %2,%1;" \
" jmp 2f;" \
"1: movl %0,%2;" \
" movl $ " _V(MTX_UNOWNED) ",%%ecx;" \
" pushl %3;" \
" " MPLOCKED "" \
" cmpxchgl %%ecx,%0;" \
" popfl;" \
"2:" \
"# exitlock_spin" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+m" (mtxp->mtx_recurse), /* 1 */ \
"=&a" (_res) /* 2 */ \
: "g" (mtxp->mtx_saveintr) /* 3 */ \
: "memory", "ecx" /* used */ ); \
})
#endif /* I386_CPU */
#endif /* _KERNEL */
#else /* !LOCORE */
/*
* Simple assembly macros to get and release spin locks.
*/
#ifdef WITNESS
#define WITNESS_ENTER(lck, reg) \
movl lck+MTX_DEBUG,reg; \
cmpl $0,MTXD_WITNESS(reg); \
jz 1f; \
pushl $0; \
pushl $0; \
pushl $MTX_SPIN; \
pushl $lck; \
call witness_enter; \
addl $0x10,%esp; \
1:
#define WITNESS_EXIT(lck, reg) \
movl lck+MTX_DEBUG,reg; \
cmpl $0,MTXD_WITNESS(reg); \
jz 1f; \
pushl $0; \
pushl $0; \
pushl $MTX_SPIN; \
pushl $lck; \
call witness_exit; \
addl $0x10,%esp; \
1:
#else
#define WITNESS_ENTER(lck, reg)
#define WITNESS_EXIT(lck, reg)
#endif
#if defined(I386_CPU)
#define MTX_ENTER(lck, reg) \
movl _curproc,reg; \
pushfl; \
cli; \
movl reg,lck+MTX_LOCK; \
popl lck+MTX_SAVEINTR; \
WITNESS_ENTER(lck, reg)
#define MTX_EXIT(lck, reg) \
WITNESS_EXIT(lck, reg) \
pushl lck+MTX_SAVEINTR; \
movl $ MTX_UNOWNED,lck+MTX_LOCK; \
popfl;
#else /* I386_CPU */
#define MTX_ENTER(lck, reg) \
movl _curproc,reg; \
pushfl; \
cli; \
9: movl $ MTX_UNOWNED,%eax; \
MPLOCKED \
cmpxchgl reg,lck+MTX_LOCK; \
jnz 9b; \
popl lck+MTX_SAVEINTR; \
WITNESS_ENTER(lck, reg)
/* Must use locked bus op (cmpxchg) when setting to unowned (barrier) */
#define MTX_EXIT(lck, reg) \
WITNESS_EXIT(lck, reg) \
pushl lck+MTX_SAVEINTR; \
movl lck+MTX_LOCK,%eax; \
movl $ MTX_UNOWNED,reg; \
MPLOCKED \
cmpxchgl reg,lck+MTX_LOCK; \
popfl;
#define MTX_ENTER_WITH_RECURSION(lck, reg) \
pushf; \
cli; \
movl lck+MTX_LOCK,%eax; \
cmpl _curproc,%eax; \
jne 7f; \
incl lck+MTX_RECURSE; \
jmp 8f; \
7: movl $ MTX_UNOWNED,%eax; \
MPLOCKED \
cmpxchgl reg,lck+MTX_LOCK; \
jnz 7b; \
popl lck+MTX_SAVEINTR; \
jmp 9f; \
8: add $4,%esp; \
9: WITNESS_ENTER(lck, reg)
#define MTX_EXIT_WITH_RECURSION(lck, reg) \
WITNESS_EXIT(lck, reg) \
movl lck+MTX_RECURSE,%eax; \
decl %eax; \
js 8f; \
movl %eax,lck+MTX_RECURSE; \
jmp 9f; \
8: pushl lck+MTX_SAVEINTR; \
movl lck+MTX_LOCK,%eax; \
movl $ MTX_UNOWNED,reg; \
MPLOCKED \
cmpxchgl reg,lck+MTX_LOCK; \
popf; \
9:
#endif /* I386_CPU */
#endif /* !LOCORE */
#endif /* __MACHINE_MUTEX_H */