6fe65214f2
using atomic_cmpset_rel_ptr() instead for _release_lock_quick(). When atomic_store_rel_ptr() is functional and MP safe, then this can be reverted.
372 lines
10 KiB
C
372 lines
10 KiB
C
/*-
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* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Berkeley Software Design Inc's name may not be used to endorse or
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* promote products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
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* $FreeBSD$
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*/
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#ifndef _MACHINE_MUTEX_H_
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#define _MACHINE_MUTEX_H_
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#ifndef LOCORE
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#ifdef _KERNEL
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#include <machine/psl.h>
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/* Global locks */
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extern struct mtx clock_lock;
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/*
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* Debugging
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*/
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#ifdef MUTEX_DEBUG
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#ifdef _KERN_MUTEX_C_
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char STR_IEN[] = "fl & PSL_I";
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char STR_IDIS[] = "!(fl & PSL_I)";
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char STR_SIEN[] = "mpp->mtx_saveintr & PSL_I";
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#else /* _KERN_MUTEX_C_ */
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extern char STR_IEN[];
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extern char STR_IDIS[];
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extern char STR_SIEN[];
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#endif /* _KERN_MUTEX_C_ */
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#endif /* MUTEX_DEBUG */
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#define ASS_IEN MPASS2(read_eflags() & PSL_I, STR_IEN)
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#define ASS_IDIS MPASS2((read_eflags() & PSL_I) == 0, STR_IDIS)
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#define ASS_SIEN(mpp) MPASS2((mpp)->mtx_saveintr & PSL_I, STR_SIEN)
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#define mtx_legal2block() (read_eflags() & PSL_I)
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/* Actually release mtx_lock quickly assuming that we own it */
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#define _release_lock_quick(mp) \
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atomic_cmpset_rel_int(&(mp)->mtx_lock, (mp)->mtx_lock, MTX_UNOWNED)
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/*
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* Assembly macros (for internal use only)
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*------------------------------------------------------------------------------
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*/
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#define _V(x) __STRING(x)
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#if 0
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/* #ifndef I386_CPU */
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/*
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* For 486 and newer processors.
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*/
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/* Get a sleep lock, deal with recursion inline. */
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#define _getlock_sleep(mtxp, tid, type) ({ \
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int _res; \
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\
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__asm __volatile ( \
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" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
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" " MPLOCKED "" \
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" cmpxchgl %3,%1;" /* Try */ \
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" jz 1f;" /* Got it */ \
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" andl $" _V(MTX_FLAGMASK) ",%%eax;" /* turn off spec bits */ \
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" cmpl %%eax,%3;" /* already have it? */ \
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" je 2f;" /* yes, recurse */ \
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" pushl %4;" \
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" pushl %5;" \
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" call mtx_enter_hard;" \
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" addl $8,%%esp;" \
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" jmp 1f;" \
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"2:" \
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" " MPLOCKED "" \
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" orl $" _V(MTX_RECURSE) ",%1;" \
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" incl %2;" \
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"1:" \
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"# getlock_sleep" \
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: "=&a" (_res), /* 0 (dummy output) */ \
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"+m" (mtxp->mtx_lock), /* 1 */ \
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"+m" (mtxp->mtx_recurse) /* 2 */ \
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: "r" (tid), /* 3 (input) */ \
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"gi" (type), /* 4 */ \
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"g" (mtxp) /* 5 */ \
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: "memory", "ecx", "edx" /* used */ ); \
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})
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/* Get a spin lock, handle recursion inline (as the less common case) */
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#define _getlock_spin_block(mtxp, tid, type) ({ \
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int _res; \
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\
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__asm __volatile ( \
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" pushfl;" \
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" cli;" \
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" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
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" " MPLOCKED "" \
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" cmpxchgl %3,%1;" /* Try */ \
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" jz 2f;" /* got it */ \
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" pushl %4;" \
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" pushl %5;" \
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" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type, oflags) */ \
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" addl $12,%%esp;" \
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" jmp 1f;" \
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"2: popl %2;" /* save flags */ \
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"1:" \
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"# getlock_spin_block" \
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: "=&a" (_res), /* 0 (dummy output) */ \
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"+m" (mtxp->mtx_lock), /* 1 */ \
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"=m" (mtxp->mtx_saveintr) /* 2 */ \
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: "r" (tid), /* 3 (input) */ \
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"gi" (type), /* 4 */ \
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"g" (mtxp) /* 5 */ \
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: "memory", "ecx", "edx" /* used */ ); \
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})
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/*
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* Get a lock without any recursion handling. Calls the hard enter function if
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* we can't get it inline.
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*/
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#define _getlock_norecurse(mtxp, tid, type) ({ \
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int _res; \
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\
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__asm __volatile ( \
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" movl $" _V(MTX_UNOWNED) ",%%eax;" /* Unowned cookie */ \
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" " MPLOCKED "" \
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" cmpxchgl %2,%1;" /* Try */ \
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" jz 1f;" /* got it */ \
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" pushl %3;" \
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" pushl %4;" \
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" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type) */ \
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" addl $8,%%esp;" \
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"1:" \
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"# getlock_norecurse" \
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: "=&a" (_res), /* 0 (dummy output) */ \
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"+m" (mtxp->mtx_lock) /* 1 */ \
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: "r" (tid), /* 2 (input) */ \
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"gi" (type), /* 3 */ \
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"g" (mtxp) /* 4 */ \
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: "memory", "ecx", "edx" /* used */ ); \
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})
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/*
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* Release a sleep lock assuming we haven't recursed on it, recursion is handled
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* in the hard function.
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*/
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#define _exitlock_norecurse(mtxp, tid, type) ({ \
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int _tid = (int)(tid); \
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\
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__asm __volatile ( \
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" " MPLOCKED "" \
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" cmpxchgl %4,%0;" /* try easy rel */ \
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" jz 1f;" /* released! */ \
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" pushl %2;" \
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" pushl %3;" \
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" call mtx_exit_hard;" \
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" addl $8,%%esp;" \
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"1:" \
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"# exitlock_norecurse" \
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: "+m" (mtxp->mtx_lock), /* 0 */ \
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"+a" (_tid) /* 1 */ \
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: "gi" (type), /* 2 (input) */ \
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"g" (mtxp), /* 3 */ \
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"r" (MTX_UNOWNED) /* 4 */ \
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: "memory", "ecx", "edx" /* used */ ); \
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})
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/*
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* Release a sleep lock when its likely we recursed (the code to
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* deal with simple recursion is inline).
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*/
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#define _exitlock(mtxp, tid, type) ({ \
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int _tid = (int)(tid); \
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\
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__asm __volatile ( \
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" " MPLOCKED "" \
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" cmpxchgl %5,%0;" /* try easy rel */ \
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" jz 1f;" /* released! */ \
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" testl $" _V(MTX_RECURSE) ",%%eax;" /* recursed? */ \
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" jnz 3f;" /* handle recursion */ \
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/* Lock not recursed and contested: do the hard way */ \
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" pushl %3;" \
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" pushl %4;" \
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" call mtx_exit_hard;" /* mtx_exit_hard(mtxp,type) */ \
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" addl $8,%%esp;" \
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" jmp 1f;" \
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/* lock recursed, lower recursion level */ \
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"3: decl %1;" /* one less level */ \
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" jnz 1f;" /* still recursed, done */ \
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" lock; andl $~" _V(MTX_RECURSE) ",%0;" /* turn off recurse flag */ \
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"1:" \
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"# exitlock" \
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: "+m" (mtxp->mtx_lock), /* 0 */ \
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"+m" (mtxp->mtx_recurse), /* 1 */ \
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"+a" (_tid) /* 2 */ \
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: "gi" (type), /* 3 (input) */ \
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"g" (mtxp), /* 4 */ \
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"r" (MTX_UNOWNED) /* 5 */ \
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: "memory", "ecx", "edx" /* used */ ); \
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})
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/*
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* Release a spin lock (with possible recursion).
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*
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* We use cmpxchgl to clear lock (instead of simple store) to flush posting
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* buffers and make the change visible to other CPU's.
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*/
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#define _exitlock_spin(mtxp) ({ \
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int _res; \
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\
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__asm __volatile ( \
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" movl %1,%2;" \
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" decl %2;" \
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" js 1f;" \
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" movl %2,%1;" \
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" jmp 2f;" \
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"1: movl %0,%2;" \
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" movl $ " _V(MTX_UNOWNED) ",%%ecx;" \
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" pushl %3;" \
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" " MPLOCKED "" \
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" cmpxchgl %%ecx,%0;" \
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" popfl;" \
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"2:" \
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"# exitlock_spin" \
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: "+m" (mtxp->mtx_lock), /* 0 */ \
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"+m" (mtxp->mtx_recurse), /* 1 */ \
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"=&a" (_res) /* 2 */ \
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: "g" (mtxp->mtx_saveintr) /* 3 */ \
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: "memory", "ecx" /* used */ ); \
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})
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#endif /* I386_CPU */
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#endif /* _KERNEL */
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#else /* !LOCORE */
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/*
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* Simple assembly macros to get and release spin locks.
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*/
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#ifdef WITNESS
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#define WITNESS_ENTER(lck, reg) \
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movl lck+MTX_DEBUG,reg; \
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cmpl $0,MTXD_WITNESS(reg); \
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jz 1f; \
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pushl $0; \
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pushl $0; \
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pushl $MTX_SPIN; \
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pushl $lck; \
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call witness_enter; \
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addl $0x10,%esp; \
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1:
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#define WITNESS_EXIT(lck, reg) \
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movl lck+MTX_DEBUG,reg; \
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cmpl $0,MTXD_WITNESS(reg); \
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jz 1f; \
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pushl $0; \
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pushl $0; \
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pushl $MTX_SPIN; \
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pushl $lck; \
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call witness_exit; \
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addl $0x10,%esp; \
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1:
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#else
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#define WITNESS_ENTER(lck, reg)
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#define WITNESS_EXIT(lck, reg)
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#endif
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#if defined(I386_CPU)
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#define MTX_ENTER(lck, reg) \
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movl _curproc,reg; \
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pushfl; \
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cli; \
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movl reg,lck+MTX_LOCK; \
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popl lck+MTX_SAVEINTR; \
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WITNESS_ENTER(lck, reg)
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#define MTX_EXIT(lck, reg) \
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WITNESS_EXIT(lck, reg) \
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pushl lck+MTX_SAVEINTR; \
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movl $ MTX_UNOWNED,lck+MTX_LOCK; \
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popfl;
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#else /* I386_CPU */
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#define MTX_ENTER(lck, reg) \
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movl _curproc,reg; \
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pushfl; \
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cli; \
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9: movl $ MTX_UNOWNED,%eax; \
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MPLOCKED \
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cmpxchgl reg,lck+MTX_LOCK; \
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jnz 9b; \
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popl lck+MTX_SAVEINTR; \
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WITNESS_ENTER(lck, reg)
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/* Must use locked bus op (cmpxchg) when setting to unowned (barrier) */
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#define MTX_EXIT(lck, reg) \
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WITNESS_EXIT(lck, reg) \
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pushl lck+MTX_SAVEINTR; \
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movl lck+MTX_LOCK,%eax; \
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movl $ MTX_UNOWNED,reg; \
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MPLOCKED \
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cmpxchgl reg,lck+MTX_LOCK; \
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popfl;
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#define MTX_ENTER_WITH_RECURSION(lck, reg) \
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pushf; \
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cli; \
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movl lck+MTX_LOCK,%eax; \
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cmpl _curproc,%eax; \
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jne 7f; \
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incl lck+MTX_RECURSE; \
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jmp 8f; \
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7: movl $ MTX_UNOWNED,%eax; \
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MPLOCKED \
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cmpxchgl reg,lck+MTX_LOCK; \
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jnz 7b; \
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popl lck+MTX_SAVEINTR; \
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jmp 9f; \
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8: add $4,%esp; \
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9: WITNESS_ENTER(lck, reg)
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#define MTX_EXIT_WITH_RECURSION(lck, reg) \
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WITNESS_EXIT(lck, reg) \
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movl lck+MTX_RECURSE,%eax; \
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decl %eax; \
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js 8f; \
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movl %eax,lck+MTX_RECURSE; \
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jmp 9f; \
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8: pushl lck+MTX_SAVEINTR; \
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movl lck+MTX_LOCK,%eax; \
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movl $ MTX_UNOWNED,reg; \
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MPLOCKED \
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cmpxchgl reg,lck+MTX_LOCK; \
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popf; \
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9:
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#endif /* I386_CPU */
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#endif /* !LOCORE */
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#endif /* __MACHINE_MUTEX_H */
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