| 0,0 → 1,60 |
|---|
| # |
| # Copyright (C) 2001-2004 Jakub Jermar |
| # All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions |
| # are met: |
| # |
| # - Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # - 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. |
| # - The name of the author may not be used to endorse or promote products |
| # derived from this software without specific prior written permission. |
| # |
| # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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. |
| # |
| |
| .text |
| |
| #ifdef CONFIG_SMP |
| |
| .global spinlock_arch |
| |
| # |
| # This is a bus-and-hyperthreading-friendly implementation of spinlock |
| # |
| spinlock_arch: |
| pushl %eax |
| pushl %ebx |
| |
| movl 12(%esp),%ebx |
| |
| 0: |
| #ifdef CONFIG_HT |
| pause # Pentium 4's with HT love this instruction |
| #endif |
| movl (%ebx),%eax |
| testl %eax,%eax |
| jnz 0b # lightweight looping while it is locked |
| incl %eax |
| xchgl %eax,(%ebx) # now use the atomic operation |
| testl %eax,%eax |
| jnz 0b |
| |
| popl %ebx |
| popl %eax |
| ret |
| |
| #endif |