/*
- * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2006 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License"). You may not use this file except in compliance with the
+ * License. Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
*
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#include <sys/appleapiopts.h>
#include <machine/cpu_capabilities.h>
#include <machine/commpage.h>
+#include <mach/i386/syscall_sw.h>
+
-/*
- * We need a relative branch within the comm page, and don't want the linker
- * to relocate it, so we have to hand-code the instructions. LEN is to account
- * for the length of a .long, since the jmp is relative to the next instruction.
- */
-
-#define JNZ .byte 0x0f, 0x85; .long
-#define JMP .byte 0xe9; .long
-#define LEN 4
-
-/*
- * Branch prediction prefixes
- */
-
-#define LIKELY .byte 0x3e
-#define UNLIKELY .byte 0x2e
#define MP_SPIN_TRIES 1024
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
COMMPAGE_DESCRIPTOR(spin_lock_try_up,_COMM_PAGE_SPINLOCK_TRY,kUP,0)
+
.align 4, 0x90
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
COMMPAGE_DESCRIPTOR(spin_lock_try_mp,_COMM_PAGE_SPINLOCK_TRY,0,kUP)
-.set Lrelinquish_off, _COMM_PAGE_RELINQUISH - _COMM_PAGE_SPINLOCK_LOCK
.align 4, 0x90
Lspin_lock_up:
movl 4(%esp), %ecx
xorl %eax, %eax
-.set Lretry, . - Lspin_lock_up
- cmpxchgl %ecx, (%ecx)
- UNLIKELY
- JNZ Lrelinquish_off - . + Lspin_lock_up - LEN
+ orl $-1, %edx
+ cmpxchgl %edx, (%ecx)
+ jnz,pn 1f /* predict not taken */
ret
+1:
+ /* failed to get lock so relinquish the processor immediately on UP */
+ 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 */
+ int $(MACH_INT)
+ addl $16, %esp /* adjust stack*/
+ jmp Lspin_lock_up
COMMPAGE_DESCRIPTOR(spin_lock_up,_COMM_PAGE_SPINLOCK_LOCK,kUP,0)
+
.align 4, 0x90
Lspin_lock_mp:
movl 4(%esp), %ecx
xorl %eax, %eax
0:
+ orl $-1, %edx
lock
- cmpxchgl %ecx, (%ecx)
- UNLIKELY
- jnz 1f
+ cmpxchgl %edx, (%ecx)
+ jnz,pn 1f /* predict not taken */
ret
1:
xorl %eax, %eax
2:
pause
cmpl %eax, (%ecx)
- LIKELY
- jz 0b
+ jz,pt 0b /* favor success and slow down spin loop */
decl %edx
- LIKELY
- jnz 2b
- JMP Lrelinquish_off - . + Lspin_lock_mp - LEN
+ jnz,pn 2b /* slow down spin loop with a mispredict */
+ /* failed to get lock after spinning so relinquish */
+ 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 */
+ int $(MACH_INT)
+ addl $16, %esp /* adjust stack*/
+ jmp Lspin_lock_mp
COMMPAGE_DESCRIPTOR(spin_lock_mp,_COMM_PAGE_SPINLOCK_LOCK,0,kUP)
+
.align 4, 0x90
Lspin_unlock:
movl 4(%esp), %ecx
COMMPAGE_DESCRIPTOR(spin_unlock,_COMM_PAGE_SPINLOCK_UNLOCK,0,0)
+
+/* ============================ 64-bit versions follow ===================== */
+
+
+ .text
+ .code64
.align 4, 0x90
-Lrelinquish: /* relinquish the processor */
- pushl $1 /* 1 ms */
- pushl $1 /* SWITCH_OPTION_DEPRESS */
- pushl $0 /* THREAD_NULL */
- 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 */
- JMP Lretry - Lrelinquish_off - . + Lrelinquish - LEN
-
- COMMPAGE_DESCRIPTOR(relinquish,_COMM_PAGE_RELINQUISH,0,0)
+
+Lspin_lock_try_up_64:
+ xorl %eax, %eax
+ orl $-1, %edx
+ cmpxchgl %edx, (%rdi)
+ setz %dl
+ movzbl %dl, %eax
+ ret
+
+ COMMPAGE_DESCRIPTOR(spin_lock_try_up_64,_COMM_PAGE_SPINLOCK_TRY,kUP,0)
+
+
+ .align 4, 0x90
+Lspin_lock_try_mp_64:
+ xorl %eax, %eax
+ orl $-1, %edx
+ lock
+ cmpxchgl %edx, (%rdi)
+ setz %dl
+ movzbl %dl, %eax
+ ret
+
+ COMMPAGE_DESCRIPTOR(spin_lock_try_mp_64,_COMM_PAGE_SPINLOCK_TRY,0,kUP)
+
+
+ .align 4, 0x90
+Lspin_lock_up_64:
+ movq %rdi,%r8
+0:
+ xorl %eax, %eax
+ orl $-1, %edx
+ cmpxchgl %edx, (%r8)
+ jnz,pn 1f /* predict not taken */
+ ret
+1:
+ /* failed to get lock so relinquish the processor immediately on UP */
+ xorl %edi,%edi /* THREAD_NULL */
+ movl $1,%esi /* SWITCH_OPTION_DEPRESS */
+ movl $1,%edx /* 1 ms */
+ movl $(SYSCALL_CONSTRUCT_MACH(61)),%eax /* 61 = thread_switch */
+ syscall
+ jmp 0b
+
+ COMMPAGE_DESCRIPTOR(spin_lock_up_64,_COMM_PAGE_SPINLOCK_LOCK,kUP,0)
+
+
+
+ .align 4, 0x90
+Lspin_lock_mp_64:
+ movq %rdi,%r8
+0:
+ xorl %eax, %eax
+ orl $-1, %edx
+ lock
+ cmpxchgl %edx, (%r8)
+ jnz,pn 1f /* predict not taken */
+ ret
+1:
+ xorl %eax, %eax
+ movl $(MP_SPIN_TRIES), %edx
+2: /* spin for awhile before relinquish */
+ pause
+ cmpl %eax, (%r8)
+ jz 0b
+ decl %edx
+ jnz 2b
+ /* failed to get lock after spinning so relinquish */
+ xorl %edi,%edi /* THREAD_NULL */
+ movl $1,%esi /* SWITCH_OPTION_DEPRESS */
+ movl $1,%edx /* 1 ms */
+ movl $(SYSCALL_CONSTRUCT_MACH(61)),%eax /* 61 = thread_switch */
+ syscall
+ jmp 0b
+
+ COMMPAGE_DESCRIPTOR(spin_lock_mp_64,_COMM_PAGE_SPINLOCK_LOCK,0,kUP)
+
+
+ .align 4, 0x90
+Lspin_unlock_64:
+ movl $0, (%rdi)
+ ret
+
+ COMMPAGE_DESCRIPTOR(spin_unlock_64,_COMM_PAGE_SPINLOCK_UNLOCK,0,0)
projects / apple / xnu.git / blobdiff