/*
- * Copyright (c) 2003-2006 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * 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. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * 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.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_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
COMMPAGE_DESCRIPTOR(spin_lock_try_up,_COMM_PAGE_SPINLOCK_TRY,kUP,0)
-
.align 4, 0x90
Lspin_lock_try_mp:
movl 4(%esp), %ecx
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
orl $-1, %edx
cmpxchgl %edx, (%ecx)
- jnz,pn 1f /* predict not taken */
+ UNLIKELY
+ JNZ Lrelinquish_off - . + Lspin_lock_up - LEN
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
orl $-1, %edx
lock
cmpxchgl %edx, (%ecx)
- jnz,pn 1f /* predict not taken */
+ UNLIKELY
+ jnz 1f
ret
1:
xorl %eax, %eax
2:
pause
cmpl %eax, (%ecx)
- jz,pt 0b /* favor success and slow down spin loop */
+ LIKELY
+ jz 0b
decl %edx
- 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
+ LIKELY
+ jnz 2b
+ JMP Lrelinquish_off - . + Lspin_lock_mp - LEN
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 */
+ pushl $0 /* push dummy stack ret addr */
+ movl $-61, %eax /* syscall_thread_switch */
+ lcall $7, $0
+ addl $16, %esp /* adjust stack*/
+ xorl %eax, %eax /* set %eax to 0 again */
+ JMP Lretry - Lrelinquish_off - . + Lrelinquish - LEN
-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)
+ COMMPAGE_DESCRIPTOR(relinquish,_COMM_PAGE_RELINQUISH,0,0)
projects / apple / xnu.git / blobdiff