/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* 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.
+ * 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.
+ *
+ * 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
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_COPYRIGHT@
* the terms and conditions for use and redistribution.
*/
-#include <cpus.h>
-#include <mach_rt.h>
-#include <platforms.h>
#include <mach_ldebug.h>
#include <i386/asm.h>
-#include <kern/etap_options.h>
+#include <i386/eflags.h>
+#include <i386/trap.h>
+#include <config_dtrace.h>
+#include <i386/mp.h>
#include "assym.s"
-/*
- * When performance isn't the only concern, it's
- * nice to build stack frames...
- */
-#define BUILD_STACK_FRAMES ((MACH_LDEBUG || ETAP_LOCK_TRACE) && MACH_KDB)
-
-#if BUILD_STACK_FRAMES
-
-#define L_PC 4(%ebp)
-#define L_ARG0 8(%ebp)
-#define L_ARG1 12(%ebp)
-
-#define SWT_HI -4(%ebp)
-#define SWT_LO -8(%ebp)
-#define MISSED -12(%ebp)
-
-#else /* BUILD_STACK_FRAMES */
-
-#undef FRAME
-#undef EMARF
-#define FRAME
-#define EMARF
-#define L_PC (%esp)
-#define L_ARG0 4(%esp)
-#define L_ARG1 8(%esp)
-
-#endif /* BUILD_STACK_FRAMES */
-
-
-#define M_ILK (%edx)
-#define M_LOCKED 1(%edx)
-#define M_WAITERS 2(%edx)
-#define M_PROMOTED_PRI 4(%edx)
-#if MACH_LDEBUG
-#define M_TYPE 6(%edx)
-#define M_PC 10(%edx)
-#define M_THREAD 14(%edx)
-#endif /* MACH_LDEBUG */
-
-#include <i386/AT386/mp/mp.h>
-#if (NCPUS > 1)
-#define CX(addr,reg) addr(,reg,4)
+#define PAUSE rep; nop
+
+#include <i386/pal_lock_asm.h>
+
+#define LEAF_ENTRY(name) \
+ Entry(name)
+
+#define LEAF_RET \
+ ret
+
+/* For x86_64, the varargs ABI requires that %al indicate
+ * how many SSE register contain arguments. In our case, 0 */
+#define ALIGN_STACK() and $0xFFFFFFFFFFFFFFF0, %rsp ;
+#define LOAD_STRING_ARG0(label) leaq label(%rip), %rdi ;
+#define LOAD_ARG1(x) mov x, %esi ;
+#define LOAD_PTR_ARG1(x) mov x, %rsi ;
+#define CALL_PANIC() xorb %al,%al ; call EXT(panic) ;
+
+#define PREEMPTION_DISABLE \
+ incl %gs:CPU_PREEMPTION_LEVEL
+
+#define PREEMPTION_LEVEL_DEBUG 1
+#if PREEMPTION_LEVEL_DEBUG
+#define PREEMPTION_ENABLE \
+ decl %gs:CPU_PREEMPTION_LEVEL ; \
+ js 17f ; \
+ jnz 19f ; \
+ testl $AST_URGENT,%gs:CPU_PENDING_AST ; \
+ jz 19f ; \
+ PUSHF ; \
+ testl $EFL_IF, S_PC ; \
+ jz 18f ; \
+ POPF ; \
+ int $(T_PREEMPT) ; \
+ jmp 19f ; \
+17: \
+ call _preemption_underflow_panic ; \
+18: \
+ POPF ; \
+19:
#else
-#define CPU_NUMBER(reg)
-#define CX(addr,reg) addr
-#endif /* (NCPUS > 1) */
+#define PREEMPTION_ENABLE \
+ decl %gs:CPU_PREEMPTION_LEVEL ; \
+ jnz 19f ; \
+ testl $AST_URGENT,%gs:CPU_PENDING_AST ; \
+ jz 19f ; \
+ PUSHF ; \
+ testl $EFL_IF, S_PC ; \
+ jz 18f ; \
+ POPF ; \
+ int $(T_PREEMPT) ; \
+ jmp 19f ; \
+18: \
+ POPF ; \
+19:
+#endif
-#if MACH_LDEBUG
/*
- * Routines for general lock debugging.
+ * For most routines, the hw_lock_t pointer is loaded into a
+ * register initially, and then either a byte or register-sized
+ * word is loaded/stored to the pointer
*/
-#define S_TYPE 4(%edx)
-#define S_PC 8(%edx)
-#define S_THREAD 12(%edx)
-#define S_DURATIONH 16(%edx)
-#define S_DURATIONL 20(%edx)
-
-/*
- * Checks for expected lock types and calls "panic" on
- * mismatch. Detects calls to Mutex functions with
- * type simplelock and vice versa.
- */
-#define CHECK_MUTEX_TYPE() \
- cmpl $ MUTEX_TAG,M_TYPE ; \
- je 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "not a mutex!" ; \
- .text ; \
-1:
-
-#define CHECK_SIMPLE_LOCK_TYPE() \
- cmpl $ SIMPLE_LOCK_TAG,S_TYPE ; \
- je 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "not a simple lock!" ; \
- .text ; \
-1:
/*
- * If one or more simplelocks are currently held by a thread,
- * an attempt to acquire a mutex will cause this check to fail
- * (since a mutex lock may context switch, holding a simplelock
- * is not a good thing).
- */
-#if 0 /*MACH_RT - 11/12/99 - lion@apple.com disable check for now*/
-#define CHECK_PREEMPTION_LEVEL() \
- movl $ CPD_PREEMPTION_LEVEL,%eax ; \
- cmpl $0,%gs:(%eax) ; \
- je 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "preemption_level != 0!" ; \
- .text ; \
-1:
-#else /* MACH_RT */
-#define CHECK_PREEMPTION_LEVEL()
-#endif /* MACH_RT */
-
-#define CHECK_NO_SIMPLELOCKS() \
- movl $ CPD_SIMPLE_LOCK_COUNT,%eax ; \
- cmpl $0,%gs:(%eax) ; \
- je 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "simple_locks_held!" ; \
- .text ; \
-1:
-
-/*
- * Verifies return to the correct thread in "unlock" situations.
- */
-#define CHECK_THREAD(thd) \
- movl $ CPD_ACTIVE_THREAD,%eax ; \
- movl %gs:(%eax),%ecx ; \
- testl %ecx,%ecx ; \
- je 1f ; \
- cmpl %ecx,thd ; \
- je 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "wrong thread!" ; \
- .text ; \
-1:
-
-#define CHECK_MYLOCK(thd) \
- movl $ CPD_ACTIVE_THREAD,%eax ; \
- movl %gs:(%eax),%ecx ; \
- testl %ecx,%ecx ; \
- je 1f ; \
- cmpl %ecx,thd ; \
- jne 1f ; \
- pushl $2f ; \
- call EXT(panic) ; \
- hlt ; \
- .data ; \
-2: String "mylock attempt!" ; \
- .text ; \
-1:
-
-#define METER_SIMPLE_LOCK_LOCK(reg) \
- pushl reg ; \
- call EXT(meter_simple_lock) ; \
- popl reg
-
-#define METER_SIMPLE_LOCK_UNLOCK(reg) \
- pushl reg ; \
- call EXT(meter_simple_unlock) ; \
- popl reg
-
-#else /* MACH_LDEBUG */
-#define CHECK_MUTEX_TYPE()
-#define CHECK_SIMPLE_LOCK_TYPE
-#define CHECK_THREAD(thd)
-#define CHECK_PREEMPTION_LEVEL()
-#define CHECK_NO_SIMPLELOCKS()
-#define CHECK_MYLOCK(thd)
-#define METER_SIMPLE_LOCK_LOCK(reg)
-#define METER_SIMPLE_LOCK_UNLOCK(reg)
-#endif /* MACH_LDEBUG */
-
-
-/*
- * void hw_lock_init(hw_lock_t)
+ * void hw_lock_byte_init(volatile uint8_t *)
*
- * Initialize a hardware lock.
+ * Initialize a hardware byte lock.
*/
-ENTRY(hw_lock_init)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
- xorl %eax,%eax
- movb %al,0(%edx) /* clear the lock */
- EMARF
- ret
+LEAF_ENTRY(hw_lock_byte_init)
+ movb $0, (%rdi) /* clear the lock */
+ LEAF_RET
/*
- * void hw_lock_lock(hw_lock_t)
- * unsigned int hw_lock_to(hw_lock_t, unsigned int)
+ * void hw_lock_byte_lock(uint8_t *lock_byte)
*
- * Acquire lock, spinning until it becomes available.
- * XXX: For now, we don't actually implement the timeout.
- * MACH_RT: also return with preemption disabled.
+ * Acquire byte sized lock operand, spinning until it becomes available.
+ * return with preemption disabled.
*/
-ENTRY2(hw_lock_lock,hw_lock_to)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-1: DISABLE_PREEMPTION(%eax)
- movb $1,%cl
- xchgb 0(%edx),%cl /* try to acquire the HW lock */
- testb %cl,%cl /* success? */
+LEAF_ENTRY(hw_lock_byte_lock)
+ PREEMPTION_DISABLE
+ movl $1, %ecx /* Set lock value */
+1:
+ movb (%rdi), %al /* Load byte at address */
+ testb %al,%al /* lock locked? */
+ jne 3f /* branch if so */
+ lock; cmpxchg %cl,(%rdi) /* attempt atomic compare exchange */
jne 3f
- movl $1,%eax /* In case this was a timeout call */
- EMARF /* if yes, then nothing left to do */
- ret
-
-3: ENABLE_PREEMPTION(%eax) /* no reason we can't be preemptable now */
-
- movb $1,%cl
-2: testb %cl,0(%edx) /* spin checking lock value in cache */
- jne 2b /* non-zero means locked, keep spinning */
- jmp 1b /* zero means unlocked, try to grab it */
+ LEAF_RET /* if yes, then nothing left to do */
+3:
+ PAUSE /* pause for hyper-threading */
+ jmp 1b /* try again */
/*
- * void hw_lock_unlock(hw_lock_t)
+ * void hw_lock_byte_unlock(uint8_t *lock_byte)
*
- * Unconditionally release lock.
- * MACH_RT: release preemption level.
- */
-ENTRY(hw_lock_unlock)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
- xorl %eax,%eax
- xchgb 0(%edx),%al /* clear the lock... a mov instruction */
- /* ...might be cheaper and less paranoid */
- ENABLE_PREEMPTION(%eax)
- EMARF
- ret
-
-/*
- * unsigned int hw_lock_try(hw_lock_t)
- * MACH_RT: returns with preemption disabled on success.
- */
-ENTRY(hw_lock_try)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
- DISABLE_PREEMPTION(%eax)
- movb $1,%cl
- xchgb 0(%edx),%cl /* try to acquire the HW lock */
- testb %cl,%cl /* success? */
- jne 1f /* if yes, let the caller know */
-
- movl $1,%eax /* success */
- EMARF
- ret
-
-1: ENABLE_PREEMPTION(%eax) /* failure: release preemption... */
- xorl %eax,%eax /* ...and return failure */
- EMARF
- ret
-
-/*
- * unsigned int hw_lock_held(hw_lock_t)
- * MACH_RT: doesn't change preemption state.
- * N.B. Racy, of course.
+ * Unconditionally release byte sized lock operand,
+ * release preemption level.
*/
-ENTRY(hw_lock_held)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
- movb $1,%cl
- testb %cl,0(%edx) /* check lock value */
- jne 1f /* non-zero means locked */
- xorl %eax,%eax /* tell caller: lock wasn't locked */
- EMARF
- ret
-
-1: movl $1,%eax /* tell caller: lock was locked */
- EMARF
- ret
-
-
-
-#if 0
-
-
-ENTRY(_usimple_lock_init)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
- xorl %eax,%eax
- movb %al,USL_INTERLOCK(%edx) /* unlock the HW lock */
- EMARF
- ret
-
-ENTRY(_simple_lock)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
- CHECK_SIMPLE_LOCK_TYPE()
-
- DISABLE_PREEMPTION(%eax)
-
-sl_get_hw:
- movb $1,%cl
- xchgb USL_INTERLOCK(%edx),%cl /* try to acquire the HW lock */
- testb %cl,%cl /* did we succeed? */
-
-#if MACH_LDEBUG
- je 5f
- CHECK_MYLOCK(S_THREAD)
- jmp sl_get_hw
-5:
-#else /* MACH_LDEBUG */
- jne sl_get_hw /* no, try again */
-#endif /* MACH_LDEBUG */
-
-#if MACH_LDEBUG
- movl L_PC,%ecx
- movl %ecx,S_PC
- movl $ CPD_ACTIVE_THREAD,%eax
- movl %gs:(%eax),%ecx
- movl %ecx,S_THREAD
- incl CX(EXT(simple_lock_count),%eax)
-#if 0
- METER_SIMPLE_LOCK_LOCK(%edx)
-#endif
-#if NCPUS == 1
- pushf
- pushl %edx
- cli
- call EXT(lock_stack_push)
- popl %edx
- popfl
-#endif /* NCPUS == 1 */
-#endif /* MACH_LDEBUG */
-
- EMARF
- ret
-
-ENTRY(_simple_lock_try)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
- CHECK_SIMPLE_LOCK_TYPE()
-
- DISABLE_PREEMPTION(%eax)
-
- movb $1,%cl
- xchgb USL_INTERLOCK(%edx),%cl /* try to acquire the HW lock */
- testb %cl,%cl /* did we succeed? */
- jne 1f /* no, return failure */
-
-#if MACH_LDEBUG
- movl L_PC,%ecx
- movl %ecx,S_PC
- movl $ CPD_ACTIVE_THREAD,%eax
- movl %gs:(%eax),%ecx
- movl %ecx,S_THREAD
- incl CX(EXT(simple_lock_count),%eax)
-#if 0
- METER_SIMPLE_LOCK_LOCK(%edx)
-#endif
-#if NCPUS == 1
- pushf
- pushl %edx
- cli
- call EXT(lock_stack_push)
- popl %edx
- popfl
-#endif /* NCPUS == 1 */
-#endif /* MACH_LDEBUG */
-
- movl $1,%eax /* return success */
-
- EMARF
- ret
-
-1:
- ENABLE_PREEMPTION(%eax)
-
- xorl %eax,%eax /* and return failure */
-
- EMARF
- ret
-
-ENTRY(_simple_unlock)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
- CHECK_SIMPLE_LOCK_TYPE()
- CHECK_THREAD(S_THREAD)
-
-#if MACH_LDEBUG
- xorl %eax,%eax
- movl %eax,S_THREAD /* disown thread */
- MP_DISABLE_PREEMPTION(%eax)
- CPU_NUMBER(%eax)
- decl CX(EXT(simple_lock_count),%eax)
- MP_ENABLE_PREEMPTION(%eax)
-#if 0
- METER_SIMPLE_LOCK_UNLOCK(%edx)
-#endif
-#if NCPUS == 1
- pushf
- pushl %edx
- cli
- call EXT(lock_stack_pop)
- popl %edx
- popfl
-#endif /* NCPUS == 1 */
-#endif /* MACH_LDEBUG */
-
- xorb %cl,%cl
- xchgb USL_INTERLOCK(%edx),%cl /* unlock the HW lock */
-
- ENABLE_PREEMPTION(%eax)
-
- EMARF
- ret
-
-#endif /* 0 */
-
-
-ENTRY(mutex_init)
- FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
- xorl %eax,%eax
- movb %al,M_ILK /* clear interlock */
- movb %al,M_LOCKED /* clear locked flag */
- movw %ax,M_WAITERS /* init waiter count */
- movw %ax,M_PROMOTED_PRI
-
-#if MACH_LDEBUG
- movl $ MUTEX_TAG,M_TYPE /* set lock type */
- movl %eax,M_PC /* init caller pc */
- movl %eax,M_THREAD /* and owning thread */
-#endif
-#if ETAP_LOCK_TRACE
- movl L_ARG1,%ecx /* fetch event type */
- pushl %ecx /* push event type */
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_init) /* init ETAP data */
- addl $8,%esp
-#endif /* ETAP_LOCK_TRACE */
-
- EMARF
- ret
-
-ENTRY2(mutex_lock,_mutex_lock)
- FRAME
-
-#if ETAP_LOCK_TRACE
- subl $12,%esp /* make room for locals */
- movl $0,SWT_HI /* set wait time to zero (HI) */
- movl $0,SWT_LO /* set wait time to zero (LO) */
- movl $0,MISSED /* clear local miss marker */
-#endif /* ETAP_LOCK_TRACE */
-
- movl L_ARG0,%edx /* fetch lock pointer */
-
- CHECK_MUTEX_TYPE()
- CHECK_NO_SIMPLELOCKS()
- CHECK_PREEMPTION_LEVEL()
-
-ml_retry:
- DISABLE_PREEMPTION(%eax)
-
-ml_get_hw:
- movb $1,%cl
- xchgb %cl,M_ILK
- testb %cl,%cl /* did we succeed? */
- jne ml_get_hw /* no, try again */
-
- movb $1,%cl
- xchgb %cl,M_LOCKED /* try to set locked flag */
- testb %cl,%cl /* is the mutex locked? */
- jne ml_fail /* yes, we lose */
-
- pushl %edx
- call EXT(mutex_lock_acquire)
- addl $4,%esp
- movl L_ARG0,%edx
-
-#if MACH_LDEBUG
- movl L_PC,%ecx
- movl %ecx,M_PC
- movl $ CPD_ACTIVE_THREAD,%eax
- movl %gs:(%eax),%ecx
- movl %ecx,M_THREAD
- testl %ecx,%ecx
- je 3f
- incl TH_MUTEX_COUNT(%ecx)
-3:
-#endif
-
- xorb %cl,%cl
- xchgb %cl,M_ILK
-
- ENABLE_PREEMPTION(%eax)
-
-#if ETAP_LOCK_TRACE
- movl L_PC,%eax /* fetch pc */
- pushl SWT_LO /* push wait time (low) */
- pushl SWT_HI /* push wait time (high) */
- pushl %eax /* push pc */
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_hold) /* collect hold timestamp */
- addl $16+12,%esp /* clean up stack, adjusting for locals */
-#endif /* ETAP_LOCK_TRACE */
-
- EMARF
- ret
-
-ml_fail:
-#if ETAP_LOCK_TRACE
- cmp $0,MISSED /* did we already take a wait timestamp? */
- jne ml_block /* yup. carry-on */
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_miss) /* get wait timestamp */
- movl %eax,SWT_HI /* set wait time (high word) */
- movl %edx,SWT_LO /* set wait time (low word) */
- popl %edx /* clean up stack */
- movl $1,MISSED /* mark wait timestamp as taken */
-#endif /* ETAP_LOCK_TRACE */
-
-ml_block:
- CHECK_MYLOCK(M_THREAD)
- xorl %eax,%eax
- pushl %eax /* no promotion here yet */
- pushl %edx /* push mutex address */
- call EXT(mutex_lock_wait) /* wait for the lock */
- addl $8,%esp
- movl L_ARG0,%edx /* refetch lock pointer */
- jmp ml_retry /* and try again */
-
-ENTRY2(mutex_try,_mutex_try)
- FRAME
-
-#if ETAP_LOCK_TRACE
- subl $8,%esp /* make room for locals */
- movl $0,SWT_HI /* set wait time to zero (HI) */
- movl $0,SWT_LO /* set wait time to zero (LO) */
-#endif /* ETAP_LOCK_TRACE */
-
- movl L_ARG0,%edx /* fetch lock pointer */
-
- CHECK_MUTEX_TYPE()
- CHECK_NO_SIMPLELOCKS()
-
- DISABLE_PREEMPTION(%eax)
-
-mt_get_hw:
- movb $1,%cl
- xchgb %cl,M_ILK
- testb %cl,%cl
- jne mt_get_hw
-
- movb $1,%cl
- xchgb %cl,M_LOCKED
- testb %cl,%cl
- jne mt_fail
-
- pushl %edx
- call EXT(mutex_lock_acquire)
- addl $4,%esp
- movl L_ARG0,%edx
-
-#if MACH_LDEBUG
- movl L_PC,%ecx
- movl %ecx,M_PC
- movl $ CPD_ACTIVE_THREAD,%ecx
- movl %gs:(%ecx),%ecx
- movl %ecx,M_THREAD
- testl %ecx,%ecx
- je 1f
- incl TH_MUTEX_COUNT(%ecx)
-1:
-#endif
-
- xorb %cl,%cl
- xchgb %cl,M_ILK
-
- ENABLE_PREEMPTION(%eax)
-
-#if ETAP_LOCK_TRACE
- movl L_PC,%eax /* fetch pc */
- pushl SWT_LO /* push wait time (low) */
- pushl SWT_HI /* push wait time (high) */
- pushl %eax /* push pc */
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_hold) /* get start hold timestamp */
- addl $16,%esp /* clean up stack, adjusting for locals */
-#endif /* ETAP_LOCK_TRACE */
-
- movl $1,%eax
-
-#if MACH_LDEBUG || ETAP_LOCK_TRACE
-#if ETAP_LOCK_TRACE
- addl $8,%esp /* pop stack claimed on entry */
-#endif
-#endif
-
- EMARF
- ret
-
-mt_fail:
-#if MACH_LDEBUG
- movl L_PC,%ecx
- movl %ecx,M_PC
- movl $ CPD_ACTIVE_THREAD,%ecx
- movl %gs:(%ecx),%ecx
- movl %ecx,M_THREAD
- testl %ecx,%ecx
- je 1f
- incl TH_MUTEX_COUNT(%ecx)
-1:
-#endif
-
- xorb %cl,%cl
- xchgb %cl,M_ILK
-
- ENABLE_PREEMPTION(%eax)
-
-#if ETAP_LOCK_TRACE
- movl L_PC,%eax /* fetch pc */
- pushl SWT_LO /* push wait time (low) */
- pushl SWT_HI /* push wait time (high) */
- pushl %eax /* push pc */
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_hold) /* get start hold timestamp */
- addl $16,%esp /* clean up stack, adjusting for locals */
-#endif /* ETAP_LOCK_TRACE */
-
- xorl %eax,%eax
-
-#if MACH_LDEBUG || ETAP_LOCK_TRACE
-#if ETAP_LOCK_TRACE
- addl $8,%esp /* pop stack claimed on entry */
-#endif
-#endif
- EMARF
- ret
+LEAF_ENTRY(hw_lock_byte_unlock)
+ movb $0, (%rdi) /* Clear the lock byte */
+ PREEMPTION_ENABLE
+ LEAF_RET
-ENTRY(mutex_unlock)
+LEAF_ENTRY(preemption_underflow_panic)
FRAME
- movl L_ARG0,%edx /* fetch lock pointer */
-
-#if ETAP_LOCK_TRACE
- pushl %edx /* push mutex address */
- call EXT(etap_mutex_unlock) /* collect ETAP data */
- popl %edx /* restore mutex address */
-#endif /* ETAP_LOCK_TRACE */
-
- CHECK_MUTEX_TYPE()
- CHECK_THREAD(M_THREAD)
-
- DISABLE_PREEMPTION(%eax)
-
-mu_get_hw:
- movb $1,%cl
- xchgb %cl,M_ILK
- testb %cl,%cl /* did we succeed? */
- jne mu_get_hw /* no, try again */
-
- cmpw $0,M_WAITERS /* are there any waiters? */
- jne mu_wakeup /* yes, more work to do */
-
-mu_doit:
-#if MACH_LDEBUG
- xorl %eax,%eax
- movl %eax,M_THREAD /* disown thread */
- movl $ CPD_ACTIVE_THREAD,%eax
- movl %gs:(%eax),%ecx
- testl %ecx,%ecx
- je 0f
- decl TH_MUTEX_COUNT(%ecx)
-0:
-#endif
-
- xorb %cl,%cl
- xchgb %cl,M_LOCKED /* unlock the mutex */
-
- xorb %cl,%cl
- xchgb %cl,M_ILK
-
- ENABLE_PREEMPTION(%eax)
-
- EMARF
- ret
-
-mu_wakeup:
- xorl %eax,%eax
- pushl %eax /* no promotion here yet */
- pushl %edx /* push mutex address */
- call EXT(mutex_unlock_wakeup)/* yes, wake a thread */
- addl $8,%esp
- movl L_ARG0,%edx /* refetch lock pointer */
- jmp mu_doit
-
-ENTRY(interlock_unlock)
- FRAME
- movl L_ARG0,%edx
-
- xorb %cl,%cl
- xchgb %cl,M_ILK
-
- ENABLE_PREEMPTION(%eax)
-
- EMARF
- ret
-
-
-ENTRY(_disable_preemption)
-#if MACH_RT
- _DISABLE_PREEMPTION(%eax)
-#endif /* MACH_RT */
- ret
-
-ENTRY(_enable_preemption)
-#if MACH_RT
-#if MACH_ASSERT
- movl $ CPD_PREEMPTION_LEVEL,%eax
- cmpl $0,%gs:(%eax)
- jg 1f
- pushl %gs:(%eax)
- pushl $2f
- call EXT(panic)
+ incl %gs:CPU_PREEMPTION_LEVEL
+ ALIGN_STACK()
+ LOAD_STRING_ARG0(16f)
+ CALL_PANIC()
hlt
.data
-2: String "_enable_preemption: preemption_level(%d) < 0!"
+16: String "Preemption level underflow, possible cause unlocking an unlocked mutex or spinlock"
.text
-1:
-#endif /* MACH_ASSERT */
- _ENABLE_PREEMPTION(%eax)
-#endif /* MACH_RT */
- ret
-ENTRY(_enable_preemption_no_check)
-#if MACH_RT
-#if MACH_ASSERT
- movl $ CPD_PREEMPTION_LEVEL,%eax
- cmpl $0,%gs:(%eax)
- jg 1f
- pushl $2f
- call EXT(panic)
- hlt
- .data
-2: String "_enable_preemption_no_check: preemption_level <= 0!"
- .text
-1:
-#endif /* MACH_ASSERT */
- _ENABLE_PREEMPTION_NO_CHECK(%eax)
-#endif /* MACH_RT */
- ret
-
-
-ENTRY(_mp_disable_preemption)
-#if MACH_RT && NCPUS > 1
- _DISABLE_PREEMPTION(%eax)
-#endif /* MACH_RT && NCPUS > 1*/
- ret
-
-ENTRY(_mp_enable_preemption)
-#if MACH_RT && NCPUS > 1
-#if MACH_ASSERT
- movl $ CPD_PREEMPTION_LEVEL,%eax
- cmpl $0,%gs:(%eax)
- jg 1f
- pushl %gs:(%eax)
- pushl $2f
- call EXT(panic)
- hlt
- .data
-2: String "_mp_enable_preemption: preemption_level (%d) <= 0!"
- .text
-1:
-#endif /* MACH_ASSERT */
- _ENABLE_PREEMPTION(%eax)
-#endif /* MACH_RT && NCPUS > 1 */
- ret
-
-ENTRY(_mp_enable_preemption_no_check)
-#if MACH_RT && NCPUS > 1
-#if MACH_ASSERT
- movl $ CPD_PREEMPTION_LEVEL,%eax
- cmpl $0,%gs:(%eax)
- jg 1f
- pushl $2f
- call EXT(panic)
- hlt
- .data
-2: String "_mp_enable_preemption_no_check: preemption_level <= 0!"
- .text
-1:
-#endif /* MACH_ASSERT */
- _ENABLE_PREEMPTION_NO_CHECK(%eax)
-#endif /* MACH_RT && NCPUS > 1 */
- ret
-
-
-ENTRY(i_bit_set)
- movl S_ARG0,%edx
- movl S_ARG1,%eax
- lock
- bts %dl,(%eax)
- ret
-
-ENTRY(i_bit_clear)
- movl S_ARG0,%edx
- movl S_ARG1,%eax
- lock
- btr %dl,(%eax)
- ret
-
-ENTRY(bit_lock)
- movl S_ARG0,%ecx
- movl S_ARG1,%eax
-1:
- lock
- bts %ecx,(%eax)
- jb 1b
- ret
-
-ENTRY(bit_lock_try)
- movl S_ARG0,%ecx
- movl S_ARG1,%eax
- lock
- bts %ecx,(%eax)
- jb bit_lock_failed
- ret /* %eax better not be null ! */
-bit_lock_failed:
- xorl %eax,%eax
- ret
-
-ENTRY(bit_unlock)
- movl S_ARG0,%ecx
- movl S_ARG1,%eax
- lock
- btr %ecx,(%eax)
- ret
projects / apple / xnu.git / blobdiff