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Nondestructive attempts to get simple locks when SL_DEBUG is defined.

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This commit is contained in:
Tor Egge 1998-01-19 17:33:08 +00:00
parent 813907f9ec
commit 281c79d603
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=32625
1 changed files with 21 additions and 19 deletions
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40
sys/i386/i386/simplelock.s
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@ -22,7 +22,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: simplelock.s,v 1.6 1997/08/31 03:17:48 fsmp Exp $
* $Id: simplelock.s,v 1.7 1997/12/15 02:18:22 tegge Exp $
*/
/*
@ -105,20 +105,21 @@ ENTRY(s_lock)
cmpl $0, _smp_active
je gotit
movl 4(%esp), %eax /* get the address of the lock */
movl 4(%esp), %edx /* get the address of the lock */
setlock:
movl _cpu_lockid, %ecx /* add cpu id portion */
incl %ecx /* add lock portion */
xchgl %ecx, (%eax)
testl %ecx, %ecx
movl $0, %eax
lock
cmpxchgl %ecx, (%edx)
jz gotit /* it was clear, return */
pushl %ecx /* save what we xchanged */
decl %ecx /* remove lock portion */
cmpl _cpu_lockid, %ecx /* do we hold it? */
pushl %eax /* save what we xchanged */
decl %eax /* remove lock portion */
cmpl _cpu_lockid, %eax /* do we hold it? */
je bad_slock /* yes, thats not good... */
addl $4, %esp /* clear the stack */
wait:
cmpl $0, (%eax) /* wait to empty */
cmpl $0, (%edx) /* wait to empty */
jne wait /* still set... */
jmp setlock /* empty again, try once more */
gotit:
@ -126,8 +127,8 @@ gotit:
ALIGN_TEXT
bad_slock:
/* %ecx (current lock) is already on the stack */
pushl %eax
/* %eax (current lock) is already on the stack */
pushl %edx
pushl _cpuid
pushl $bsl1
call _panic
@ -237,7 +238,7 @@ ENTRY(ss_lock)
cmpl $0, _smp_active
je sgotit2
movl 4(%esp), %eax /* get the address of the lock */
movl 4(%esp), %edx /* get the address of the lock */
ssetlock:
movl _cpu_lockid, %ecx /* add cpu id portion */
incl %ecx /* add lock portion */
@ -247,17 +248,18 @@ ssetlock:
#else
movl $TPR_BLOCK_HWI, lapic_tpr /* block hw INTs */
#endif
xchgl %ecx, (%eax) /* compete */
testl %ecx, %ecx
movl $0, %eax
lock
cmpxchgl %ecx, (%edx) /* compete */
jz sgotit /* it was clear, return */
pushl %ecx /* save what we xchanged */
decl %ecx /* remove lock portion */
cmpl _cpu_lockid, %ecx /* do we hold it? */
pushl %eax /* save what we xchanged */
decl %eax /* remove lock portion */
cmpl _cpu_lockid, %eax /* do we hold it? */
je sbad_slock /* yes, thats not good... */
addl $4, %esp /* clear the stack */
popl lapic_tpr /* previous value while waiting */
swait:
cmpl $0, (%eax) /* wait to empty */
cmpl $0, (%edx) /* wait to empty */
jne swait /* still set... */
jmp ssetlock /* empty again, try once more */
sgotit:
@ -267,8 +269,8 @@ sgotit2:
ALIGN_TEXT
sbad_slock:
/* %ecx (current lock) is already on the stack */
pushl %eax
/* %eax (current lock) is already on the stack */
pushl %edx
pushl _cpuid
pushl $sbsl1
call _panic