xnu-792.tar.gz

[apple/xnu.git] / osfmk / i386 / commpage / spinlocks.s

diff --git a/osfmk/i386/commpage/spinlocks.s b/osfmk/i386/commpage/spinlocks.s
index 2c7a17e4ca67c1b7ae504830ffb10c0aa296bac4..e2cb71207e507f8dc0b0e5883c9401b68b6f9fc0 100644 (file)
--- a/osfmk/i386/commpage/spinlocks.s
+++ b/osfmk/i386/commpage/spinlocks.s
@@ -49,7 +49,8 @@
 Lspin_lock_try_up:
        movl            4(%esp), %ecx 
        xorl            %eax, %eax
-       cmpxchgl        %ecx, (%ecx)
+       orl             $-1, %edx
+       cmpxchgl        %edx, (%ecx)
        setz            %dl
        movzbl          %dl, %eax
        ret
@@ -60,8 +61,9 @@ Lspin_lock_try_up:
 Lspin_lock_try_mp:
        movl            4(%esp), %ecx 
        xorl            %eax, %eax
+       orl             $-1, %edx
        lock
-       cmpxchgl        %ecx, (%ecx)
+       cmpxchgl        %edx, (%ecx)
        setz            %dl
        movzbl          %dl, %eax
        ret
@@ -75,7 +77,8 @@ Lspin_lock_up:
        movl            4(%esp), %ecx
        xorl            %eax, %eax
 .set Lretry,           . - Lspin_lock_up
-       cmpxchgl        %ecx, (%ecx)
+       orl             $-1, %edx
+       cmpxchgl        %edx, (%ecx)
        UNLIKELY
        JNZ             Lrelinquish_off - . + Lspin_lock_up - LEN
        ret
@@ -87,8 +90,9 @@ Lspin_lock_mp:
        movl            4(%esp), %ecx
        xorl            %eax, %eax
 0:
+       orl             $-1, %edx
        lock
-       cmpxchgl        %ecx, (%ecx)
+       cmpxchgl        %edx, (%ecx)
        UNLIKELY
        jnz             1f
        ret
@@ -120,11 +124,11 @@ Lrelinquish:                              /* relinquish the processor     */
        pushl           $1              /* 1 ms                         */
        pushl           $1              /* SWITCH_OPTION_DEPRESS        */
        pushl           $0              /* THREAD_NULL                  */
+       pushl           $0              /* push dummy stack ret addr    */
        movl            $-61, %eax      /* syscall_thread_switch        */
        lcall           $7, $0
-       popl            %eax            /* set %eax to 0 again          */
-       popl            %edx            /* use %edx as scratch          */
-       popl            %edx            /* reg to fixup stack           */
+       addl            $16, %esp       /* adjust stack*/
+       xorl            %eax, %eax      /* set %eax to 0 again          */
        JMP             Lretry - Lrelinquish_off - . + Lrelinquish - LEN
 
        COMMPAGE_DESCRIPTOR(relinquish,_COMM_PAGE_RELINQUISH,0,0)