X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/0b4e3aa066abc0728aacb4bbeb86f53f9737156e..db6096698656d32db7df630594bd9617ee54f828:/osfmk/i386/i386_lock.s diff --git a/osfmk/i386/i386_lock.s b/osfmk/i386/i386_lock.s index 6e58d507e..6b34073c6 100644 --- a/osfmk/i386/i386_lock.s +++ b/osfmk/i386/i386_lock.s @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2009 Apple 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@ */ /* * @OSF_COPYRIGHT@ @@ -29,70 +35,119 @@ * the terms and conditions for use and redistribution. */ -#include #include #include #include #include -#include -#include +#include +#include +#include +#include + +#include "assym.s" +#define PAUSE rep; nop + +#include /* * 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) +#define BUILD_STACK_FRAMES (GPROF) #if BUILD_STACK_FRAMES -#define L_PC 4(%ebp) -#define L_ARG0 8(%ebp) -#define L_ARG1 12(%ebp) +/* Stack-frame-relative: */ +#define L_PC B_PC +#define L_ARG0 B_ARG0 +#define L_ARG1 B_ARG1 + +#define LEAF_ENTRY(name) \ + Entry(name); \ + FRAME; \ + MCOUNT -#define SWT_HI -4(%ebp) -#define SWT_LO -8(%ebp) -#define MISSED -12(%ebp) +#define LEAF_ENTRY2(n1,n2) \ + Entry(n1); \ + Entry(n2); \ + FRAME; \ + MCOUNT -#else /* BUILD_STACK_FRAMES */ +#define LEAF_RET \ + EMARF; \ + ret -#undef FRAME -#undef EMARF -#define FRAME -#define EMARF -#define L_PC (%esp) -#define L_ARG0 4(%esp) -#define L_ARG1 8(%esp) +#else /* BUILD_STACK_FRAMES */ -#endif /* BUILD_STACK_FRAMES */ +/* Stack-pointer-relative: */ +#define L_PC S_PC +#define L_ARG0 S_ARG0 +#define L_ARG1 S_ARG1 +#define LEAF_ENTRY(name) \ + Entry(name) -#define M_ILK (%edx) -#define M_LOCKED 1(%edx) -#define M_WAITERS 2(%edx) -#if MACH_LDEBUG -#define M_TYPE 4(%edx) -#define M_PC 8(%edx) -#define M_THREAD 12(%edx) -#endif /* MACH_LDEBUG */ +#define LEAF_ENTRY2(n1,n2) \ + Entry(n1); \ + Entry(n2) + +#define LEAF_RET \ + ret + +#endif /* BUILD_STACK_FRAMES */ + + +/* Non-leaf routines always have a stack frame: */ + +#define NONLEAF_ENTRY(name) \ + Entry(name); \ + FRAME; \ + MCOUNT + +#define NONLEAF_ENTRY2(n1,n2) \ + Entry(n1); \ + Entry(n2); \ + FRAME; \ + MCOUNT + +#define NONLEAF_RET \ + EMARF; \ + ret -#include -#if (NCPUS > 1) -#define CX(addr,reg) addr(,reg,4) + +/* For x86_64, the varargs ABI requires that %al indicate + * how many SSE register contain arguments. In our case, 0 */ +#if __i386__ +#define ALIGN_STACK() subl $8, %esp; andl $0xFFFFFFF0, %esp ; +#define LOAD_STRING_ARG0(label) movl $##label, (%esp) ; +#define LOAD_ARG1(x) mov x, 4(%esp) ; +#define LOAD_PTR_ARG1(x) mov x, 4(%esp) ; +#define CALL_PANIC() call EXT(panic) ; #else -#define CPU_NUMBER(reg) -#define CX(addr,reg) addr -#endif /* (NCPUS > 1) */ +#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) ; +#endif + +#define CHECK_UNLOCK(current, owner) \ + cmp current, owner ; \ + je 1f ; \ + ALIGN_STACK() ; \ + LOAD_STRING_ARG0(2f) ; \ + CALL_PANIC() ; \ + hlt ; \ + .data ; \ +2: String "Mutex unlock attempted from non-owner thread"; \ + .text ; \ +1: #if MACH_LDEBUG /* * Routines for general lock debugging. */ -#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 @@ -100,128 +155,218 @@ * type simplelock and vice versa. */ #define CHECK_MUTEX_TYPE() \ - cmpl $MUTEX_TAG, M_TYPE ; \ + cmpl $ MUTEX_TAG,M_TYPE ; \ je 1f ; \ - pushl $2f ; \ - call EXT(panic) ; \ + ALIGN_STACK() ; \ + LOAD_STRING_ARG0(2f) ; \ + CALL_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*/ +#if MACH_RT #define CHECK_PREEMPTION_LEVEL() \ - movl $CPD_PREEMPTION_LEVEL,%eax ; \ - cmpl $0,%gs:(%eax) ; \ + cmpl $0,%gs:CPU_HIBERNATE ; \ + jne 1f ; \ + cmpl $0,%gs:CPU_PREEMPTION_LEVEL ; \ je 1f ; \ - pushl $2f ; \ - call EXT(panic) ; \ + ALIGN_STACK() ; \ + movl %gs:CPU_PREEMPTION_LEVEL, %eax ; \ + LOAD_ARG1(%eax) ; \ + LOAD_STRING_ARG0(2f) ; \ + CALL_PANIC() ; \ hlt ; \ .data ; \ -2: String "preemption_level != 0!" ; \ +2: String "preemption_level(%d) != 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 ; \ +#define CHECK_MYLOCK(current, owner) \ + cmp current, owner ; \ jne 1f ; \ - pushl $2f ; \ - call EXT(panic) ; \ + ALIGN_STACK() ; \ + LOAD_STRING_ARG0(2f) ; \ + CALL_PANIC() ; \ hlt ; \ .data ; \ -2: String "mylock attempt!" ; \ +2: String "Attempt to recursively lock a non-recursive lock"; \ .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 */ +#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 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 CONFIG_DTRACE + + .globl _lockstat_probe + .globl _lockstat_probemap + +/* + * LOCKSTAT_LABEL creates a dtrace symbol which contains + * a pointer into the lock code function body. At that + * point is a "ret" instruction that can be patched into + * a "nop" + */ + +#if defined(__i386__) + +#define LOCKSTAT_LABEL(lab) \ + .data ;\ + .globl lab ;\ + lab: ;\ + .long 9f ;\ + .text ;\ + 9: + +#define LOCKSTAT_RECORD(id, lck) \ + push %ebp ; \ + mov %esp,%ebp ; \ + sub $0x38,%esp /* size of dtrace_probe args */ ; \ + movl _lockstat_probemap + (id * 4),%eax ; \ + test %eax,%eax ; \ + je 9f ; \ + movl $0,36(%esp) ; \ + movl $0,40(%esp) ; \ + movl $0,28(%esp) ; \ + movl $0,32(%esp) ; \ + movl $0,20(%esp) ; \ + movl $0,24(%esp) ; \ + movl $0,12(%esp) ; \ + movl $0,16(%esp) ; \ + movl lck,4(%esp) /* copy lock pointer to arg 1 */ ; \ + movl $0,8(%esp) ; \ + movl %eax,(%esp) ; \ + call *_lockstat_probe ; \ +9: leave + /* ret - left to subsequent code, e.g. return values */ + +#elif defined(__x86_64__) +#define LOCKSTAT_LABEL(lab) \ + .data ;\ + .globl lab ;\ + lab: ;\ + .quad 9f ;\ + .text ;\ + 9: + +#define LOCKSTAT_RECORD(id, lck) \ + push %rbp ; \ + mov %rsp,%rbp ; \ + movl _lockstat_probemap + (id * 4)(%rip),%eax ; \ + test %eax,%eax ; \ + je 9f ; \ + mov lck, %rsi ; \ + mov %rax, %rdi ; \ + mov $0, %rdx ; \ + mov $0, %rcx ; \ + mov $0, %r8 ; \ + mov $0, %r9 ; \ + call *_lockstat_probe(%rip) ; \ +9: leave + /* ret - left to subsequent code, e.g. return values */ +#else +#error Unsupported architecture +#endif +#endif /* CONFIG_DTRACE */ + +/* + * 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 + */ + +#if defined(__i386__) +#define HW_LOCK_REGISTER %edx +#define LOAD_HW_LOCK_REGISTER mov L_ARG0, HW_LOCK_REGISTER +#define HW_LOCK_THREAD_REGISTER %ecx +#define LOAD_HW_LOCK_THREAD_REGISTER mov %gs:CPU_ACTIVE_THREAD, HW_LOCK_THREAD_REGISTER +#define HW_LOCK_MOV_WORD movl +#define HW_LOCK_EXAM_REGISTER %eax +#elif defined(__x86_64__) +#define HW_LOCK_REGISTER %rdi +#define LOAD_HW_LOCK_REGISTER +#define HW_LOCK_THREAD_REGISTER %rcx +#define LOAD_HW_LOCK_THREAD_REGISTER mov %gs:CPU_ACTIVE_THREAD, HW_LOCK_THREAD_REGISTER +#define HW_LOCK_MOV_WORD movq +#define HW_LOCK_EXAM_REGISTER %rax +#else +#error Unsupported architecture +#endif /* * void hw_lock_init(hw_lock_t) * * Initialize a hardware 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_init) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + HW_LOCK_MOV_WORD $0, (HW_LOCK_REGISTER) /* clear the lock */ + LEAF_RET + + +/* + * void hw_lock_byte_init(volatile uint8_t *) + * + * Initialize a hardware byte lock. + */ +LEAF_ENTRY(hw_lock_byte_init) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + movb $0, (HW_LOCK_REGISTER) /* clear the lock */ + LEAF_RET /* * void hw_lock_lock(hw_lock_t) @@ -229,25 +374,163 @@ ENTRY(hw_lock_init) * Acquire lock, spinning until it becomes available. * MACH_RT: also return with preemption disabled. */ -ENTRY(hw_lock_lock) - 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_lock) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + LOAD_HW_LOCK_THREAD_REGISTER /* get thread pointer */ + + PREEMPTION_DISABLE +1: + mov (HW_LOCK_REGISTER), HW_LOCK_EXAM_REGISTER + test HW_LOCK_EXAM_REGISTER,HW_LOCK_EXAM_REGISTER /* lock locked? */ + jne 3f /* branch if so */ + lock; cmpxchg HW_LOCK_THREAD_REGISTER,(HW_LOCK_REGISTER) /* try to acquire the HW lock */ jne 3f + movl $1,%eax /* In case this was a timeout call */ + LEAF_RET /* if yes, then nothing left to do */ +3: + PAUSE /* pause for hyper-threading */ + jmp 1b /* try again */ - EMARF /* if yes, then nothing left to do */ - ret +/* + * void hw_lock_byte_lock(uint8_t *lock_byte) + * + * Acquire byte sized lock operand, spinning until it becomes available. + * MACH_RT: also return with preemption disabled. + */ + +LEAF_ENTRY(hw_lock_byte_lock) + LOAD_HW_LOCK_REGISTER /* Load lock pointer */ + PREEMPTION_DISABLE + movl $1, %ecx /* Set lock value */ +1: + movb (HW_LOCK_REGISTER), %al /* Load byte at address */ + testb %al,%al /* lock locked? */ + jne 3f /* branch if so */ + lock; cmpxchg %cl,(HW_LOCK_REGISTER) /* attempt atomic compare exchange */ + jne 3f + LEAF_RET /* if yes, then nothing left to do */ +3: + PAUSE /* pause for hyper-threading */ + jmp 1b /* try again */ -3: ENABLE_PREEMPTION(%eax) /* no reason we can't be preemptable now */ +/* + * unsigned int hw_lock_to(hw_lock_t, unsigned int) + * + * Acquire lock, spinning until it becomes available or timeout. + * MACH_RT: also return with preemption disabled. + */ +LEAF_ENTRY(hw_lock_to) +1: + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + LOAD_HW_LOCK_THREAD_REGISTER + + /* + * Attempt to grab the lock immediately + * - fastpath without timeout nonsense. + */ + PREEMPTION_DISABLE + + mov (HW_LOCK_REGISTER), HW_LOCK_EXAM_REGISTER + test HW_LOCK_EXAM_REGISTER,HW_LOCK_EXAM_REGISTER /* lock locked? */ + jne 2f /* branch if so */ + lock; cmpxchg HW_LOCK_THREAD_REGISTER,(HW_LOCK_REGISTER) /* try to acquire the HW lock */ + jne 2f /* branch on failure */ + movl $1,%eax + LEAF_RET - 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 */ +2: +#define INNER_LOOP_COUNT 1000 + /* + * Failed to get the lock so set the timeout + * and then spin re-checking the lock but pausing + * every so many (INNER_LOOP_COUNT) spins to check for timeout. + */ +#if __i386__ + movl L_ARG1,%ecx /* fetch timeout */ + push %edi + push %ebx + mov %edx,%edi + + lfence + rdtsc /* read cyclecount into %edx:%eax */ + addl %ecx,%eax /* fetch and timeout */ + adcl $0,%edx /* add carry */ + mov %edx,%ecx + mov %eax,%ebx /* %ecx:%ebx is the timeout expiry */ + mov %edi, %edx /* load lock back into %edx */ +#else + push %r9 + lfence + rdtsc /* read cyclecount into %edx:%eax */ + shlq $32, %rdx + orq %rdx, %rax /* load 64-bit quantity into %rax */ + addq %rax, %rsi /* %rsi is the timeout expiry */ +#endif + +4: + /* + * The inner-loop spin to look for the lock being freed. + */ +#if __i386__ + mov $(INNER_LOOP_COUNT),%edi +#else + mov $(INNER_LOOP_COUNT),%r9 +#endif +5: + PAUSE /* pause for hyper-threading */ + mov (HW_LOCK_REGISTER),HW_LOCK_EXAM_REGISTER /* spin checking lock value in cache */ + test HW_LOCK_EXAM_REGISTER,HW_LOCK_EXAM_REGISTER + je 6f /* zero => unlocked, try to grab it */ +#if __i386__ + decl %edi /* decrement inner loop count */ +#else + decq %r9 /* decrement inner loop count */ +#endif + jnz 5b /* time to check for timeout? */ + + /* + * Here after spinning INNER_LOOP_COUNT times, check for timeout + */ +#if __i386__ + mov %edx,%edi /* Save %edx */ + lfence + rdtsc /* cyclecount into %edx:%eax */ + xchg %edx,%edi /* cyclecount into %edi:%eax */ + cmpl %ecx,%edi /* compare high-order 32-bits */ + jb 4b /* continue spinning if less, or */ + cmpl %ebx,%eax /* compare low-order 32-bits */ + jb 4b /* continue if less, else bail */ + xor %eax,%eax /* with 0 return value */ + pop %ebx + pop %edi +#else + lfence + rdtsc /* cyclecount into %edx:%eax */ + shlq $32, %rdx + orq %rdx, %rax /* load 64-bit quantity into %rax */ + cmpq %rsi, %rax /* compare to timeout */ + jb 4b /* continue spinning if less, or */ + xor %rax,%rax /* with 0 return value */ + pop %r9 +#endif + LEAF_RET + +6: + /* + * Here to try to grab the lock that now appears to be free + * after contention. + */ + LOAD_HW_LOCK_THREAD_REGISTER + lock; cmpxchg HW_LOCK_THREAD_REGISTER,(HW_LOCK_REGISTER) /* try to acquire the HW lock */ + jne 4b /* no - spin again */ + movl $1,%eax /* yes */ +#if __i386__ + pop %ebx + pop %edi +#else + pop %r9 +#endif + LEAF_RET /* * void hw_lock_unlock(hw_lock_t) @@ -255,560 +538,1812 @@ ENTRY(hw_lock_lock) * 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 +LEAF_ENTRY(hw_lock_unlock) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + HW_LOCK_MOV_WORD $0, (HW_LOCK_REGISTER) /* clear the lock */ + PREEMPTION_ENABLE + LEAF_RET /* - * unsigned int hw_lock_try(hw_lock_t) - * MACH_RT: returns with preemption disabled on success. + * void hw_lock_byte_unlock(uint8_t *lock_byte) + * + * Unconditionally release byte sized lock operand. + * MACH_RT: release preemption level. */ -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 */ +LEAF_ENTRY(hw_lock_byte_unlock) + LOAD_HW_LOCK_REGISTER /* Load lock pointer */ + movb $0, (HW_LOCK_REGISTER) /* Clear the lock byte */ + PREEMPTION_ENABLE + LEAF_RET +/* + * unsigned int hw_lock_try(hw_lock_t) + * MACH_RT: returns with preemption disabled on success. + */ +LEAF_ENTRY(hw_lock_try) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + LOAD_HW_LOCK_THREAD_REGISTER + PREEMPTION_DISABLE + + mov (HW_LOCK_REGISTER),HW_LOCK_EXAM_REGISTER + test HW_LOCK_EXAM_REGISTER,HW_LOCK_EXAM_REGISTER + jne 1f + lock; cmpxchg HW_LOCK_THREAD_REGISTER,(HW_LOCK_REGISTER) /* try to acquire the HW lock */ + jne 1f + movl $1,%eax /* success */ - EMARF - ret + LEAF_RET -1: ENABLE_PREEMPTION(%eax) /* failure: release preemption... */ +1: + PREEMPTION_ENABLE /* failure: release preemption... */ xorl %eax,%eax /* ...and return failure */ - EMARF - ret + LEAF_RET /* * unsigned int hw_lock_held(hw_lock_t) * MACH_RT: doesn't change preemption state. * N.B. Racy, of course. */ -ENTRY(hw_lock_held) - FRAME - movl L_ARG0,%edx /* fetch lock pointer */ +LEAF_ENTRY(hw_lock_held) + LOAD_HW_LOCK_REGISTER /* fetch lock pointer */ + mov (HW_LOCK_REGISTER),HW_LOCK_EXAM_REGISTER /* check lock value */ + test HW_LOCK_EXAM_REGISTER,HW_LOCK_EXAM_REGISTER + movl $1,%ecx + cmovne %ecx,%eax /* 0 => unlocked, 1 => locked */ + LEAF_RET - 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 - +/* + * Reader-writer lock fastpaths. These currently exist for the + * shared lock acquire, the exclusive lock acquire, the shared to + * exclusive upgrade and the release paths (where they reduce overhead + * considerably) -- these are by far the most frequently used routines + * + * The following should reflect the layout of the bitfield embedded within + * the lck_rw_t structure (see i386/locks.h). + */ +#define LCK_RW_INTERLOCK (0x1 << 16) +#define LCK_RW_PRIV_EXCL (0x1 << 24) +#define LCK_RW_WANT_UPGRADE (0x2 << 24) +#define LCK_RW_WANT_WRITE (0x4 << 24) +#define LCK_R_WAITING (0x8 << 24) +#define LCK_W_WAITING (0x10 << 24) -#if 0 +#define LCK_RW_SHARED_MASK (0xffff) +/* + * For most routines, the lck_rw_t pointer is loaded into a + * register initially, and the flags bitfield loaded into another + * register and examined + */ + +#if defined(__i386__) +#define LCK_RW_REGISTER %edx +#define LOAD_LCK_RW_REGISTER mov S_ARG0, LCK_RW_REGISTER +#define LCK_RW_FLAGS_REGISTER %eax +#define LOAD_LCK_RW_FLAGS_REGISTER mov (LCK_RW_REGISTER), LCK_RW_FLAGS_REGISTER +#elif defined(__x86_64__) +#define LCK_RW_REGISTER %rdi +#define LOAD_LCK_RW_REGISTER +#define LCK_RW_FLAGS_REGISTER %eax +#define LOAD_LCK_RW_FLAGS_REGISTER mov (LCK_RW_REGISTER), LCK_RW_FLAGS_REGISTER +#else +#error Unsupported architecture +#endif + +#define RW_LOCK_SHARED_MASK (LCK_RW_INTERLOCK | LCK_RW_WANT_UPGRADE | LCK_RW_WANT_WRITE) +/* + * void lck_rw_lock_shared(lck_rw_t *) + * + */ +Entry(lck_rw_lock_shared) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield and interlock */ + testl $(RW_LOCK_SHARED_MASK), %eax /* Eligible for fastpath? */ + jne 3f -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 + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + incl %ecx /* Increment reader refcount */ + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 2f + +#if CONFIG_DTRACE + /* + * Dtrace lockstat event: LS_LCK_RW_LOCK_SHARED_ACQUIRE + * Implemented by swapping between return and no-op instructions. + * See bsd/dev/dtrace/lockstat.c. + */ + LOCKSTAT_LABEL(_lck_rw_lock_shared_lockstat_patch_point) 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 + /* + Fall thru when patched, counting on lock pointer in LCK_RW_REGISTER + */ + LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_ACQUIRE, LCK_RW_REGISTER) +#endif ret +2: + PAUSE + jmp 1b +3: + jmp EXT(lck_rw_lock_shared_gen) -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 + +#define RW_TRY_LOCK_SHARED_MASK (LCK_RW_WANT_UPGRADE | LCK_RW_WANT_WRITE) +/* + * void lck_rw_try_lock_shared(lck_rw_t *) + * + */ +Entry(lck_rw_try_lock_shared) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield and interlock */ + testl $(LCK_RW_INTERLOCK), %eax + jne 2f + testl $(RW_TRY_LOCK_SHARED_MASK), %eax + jne 3f /* lock is busy */ + + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + incl %ecx /* Increment reader refcount */ + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 2f + +#if CONFIG_DTRACE + movl $1, %eax + /* + * Dtrace lockstat event: LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE + * Implemented by swapping between return and no-op instructions. + * See bsd/dev/dtrace/lockstat.c. + */ + LOCKSTAT_LABEL(_lck_rw_try_lock_shared_lockstat_patch_point) + ret + /* Fall thru when patched, counting on lock pointer in LCK_RW_REGISTER */ + LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, LCK_RW_REGISTER) +#endif + movl $1, %eax /* return TRUE */ + ret +2: + PAUSE + jmp 1b +3: + xorl %eax, %eax ret + +#define RW_LOCK_EXCLUSIVE_HELD (LCK_RW_WANT_WRITE | LCK_RW_WANT_UPGRADE) +/* + * int lck_rw_grab_shared(lck_rw_t *) + * + */ +Entry(lck_rw_grab_shared) + LOAD_LCK_RW_REGISTER 1: - ENABLE_PREEMPTION(%eax) - - xorl %eax,%eax /* and return failure */ + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield and interlock */ + testl $(LCK_RW_INTERLOCK), %eax + jne 5f + testl $(RW_LOCK_EXCLUSIVE_HELD), %eax + jne 3f +2: + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + incl %ecx /* Increment reader refcount */ + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 4f - EMARF + movl $1, %eax /* return success */ 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 +3: + testl $(LCK_RW_SHARED_MASK), %eax + je 4f + testl $(LCK_RW_PRIV_EXCL), %eax + je 2b +4: + xorl %eax, %eax /* return failure */ ret - -#endif /* 0 */ +5: + PAUSE + jmp 1b -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 */ + +#define RW_LOCK_EXCLUSIVE_MASK (LCK_RW_SHARED_MASK | LCK_RW_INTERLOCK | \ + LCK_RW_WANT_UPGRADE | LCK_RW_WANT_WRITE) +/* + * void lck_rw_lock_exclusive(lck_rw_t*) + * + */ +Entry(lck_rw_lock_exclusive) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and shared count */ + testl $(RW_LOCK_EXCLUSIVE_MASK), %eax /* Eligible for fastpath? */ + jne 3f /* no, go slow */ -#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 */ + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + orl $(LCK_RW_WANT_WRITE), %ecx + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 2f + +#if CONFIG_DTRACE + /* + * Dtrace lockstat event: LS_LCK_RW_LOCK_EXCL_ACQUIRE + * Implemented by swapping between return and no-op instructions. + * See bsd/dev/dtrace/lockstat.c. + */ + LOCKSTAT_LABEL(_lck_rw_lock_exclusive_lockstat_patch_point) + ret + /* Fall thru when patched, counting on lock pointer in LCK_RW_REGISTER */ + LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_ACQUIRE, LCK_RW_REGISTER) #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 +2: + PAUSE + jmp 1b +3: + jmp EXT(lck_rw_lock_exclusive_gen) -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() + +#define RW_TRY_LOCK_EXCLUSIVE_MASK (LCK_RW_SHARED_MASK | LCK_RW_WANT_UPGRADE | LCK_RW_WANT_WRITE) +/* + * void lck_rw_try_lock_exclusive(lck_rw_t *) + * + * Tries to get a write lock. + * + * Returns FALSE if the lock is not held on return. + */ +Entry(lck_rw_try_lock_exclusive) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and shared count */ + testl $(LCK_RW_INTERLOCK), %eax + jne 2f + testl $(RW_TRY_LOCK_EXCLUSIVE_MASK), %eax + jne 3f /* can't get it */ + + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + orl $(LCK_RW_WANT_WRITE), %ecx + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 2f + +#if CONFIG_DTRACE + movl $1, %eax + /* + * Dtrace lockstat event: LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE + * Implemented by swapping between return and no-op instructions. + * See bsd/dev/dtrace/lockstat.c. + */ + LOCKSTAT_LABEL(_lck_rw_try_lock_exclusive_lockstat_patch_point) + ret + /* Fall thru when patched, counting on lock pointer in LCK_RW_REGISTER */ + LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, LCK_RW_REGISTER) +#endif + movl $1, %eax /* return TRUE */ + ret +2: + PAUSE + jmp 1b +3: + xorl %eax, %eax /* return FALSE */ + ret -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 */ /* -/ Beware of a race between this code path and the inline ASM fast-path locking -/ sequence which attempts to lock a mutex by directly setting the locked flag -/ -*/ + * void lck_rw_lock_shared_to_exclusive(lck_rw_t*) + * + * fastpath can be taken if + * the current rw_shared_count == 1 + * AND the interlock is clear + * AND RW_WANT_UPGRADE is not set + * + * note that RW_WANT_WRITE could be set, but will not + * be indicative of an exclusive hold since we have + * a read count on the lock that we have not yet released + * we can blow by that state since the lck_rw_lock_exclusive + * function will block until rw_shared_count == 0 and + * RW_WANT_UPGRADE is clear... it does this check behind + * the interlock which we are also checking for + * + * to make the transition we must be able to atomically + * set RW_WANT_UPGRADE and get rid of the read count we hold + */ +Entry(lck_rw_lock_shared_to_exclusive) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and shared count */ + testl $(LCK_RW_INTERLOCK), %eax + jne 7f + testl $(LCK_RW_WANT_UPGRADE), %eax + jne 2f + + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + orl $(LCK_RW_WANT_UPGRADE), %ecx /* ask for WANT_UPGRADE */ + decl %ecx /* and shed our read count */ + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 7f + /* we now own the WANT_UPGRADE */ + testl $(LCK_RW_SHARED_MASK), %ecx /* check to see if all of the readers are drained */ + jne 8f /* if not, we need to go wait */ + +#if CONFIG_DTRACE + movl $1, %eax + /* + * Dtrace lockstat event: LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE + * Implemented by swapping between return and no-op instructions. + * See bsd/dev/dtrace/lockstat.c. + */ + LOCKSTAT_LABEL(_lck_rw_lock_shared_to_exclusive_lockstat_patch_point) + ret + /* Fall thru when patched, counting on lock pointer in LCK_RW_REGISTER */ + LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, LCK_RW_REGISTER) +#endif + movl $1, %eax /* return success */ + ret + +2: /* someone else already holds WANT_UPGRADE */ + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + decl %ecx /* shed our read count */ + testl $(LCK_RW_SHARED_MASK), %ecx + jne 3f /* we were the last reader */ + andl $(~LCK_W_WAITING), %ecx /* so clear the wait indicator */ +3: + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 7f + +#if __i386__ + pushl %eax /* go check to see if we need to */ + push %edx /* wakeup anyone */ + call EXT(lck_rw_lock_shared_to_exclusive_failure) + addl $8, %esp +#else + mov %eax, %esi /* put old flags as second arg */ + /* lock is alread in %rdi */ + call EXT(lck_rw_lock_shared_to_exclusive_failure) +#endif + ret /* and pass the failure return along */ +7: + PAUSE + jmp 1b +8: + jmp EXT(lck_rw_lock_shared_to_exclusive_success) - 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 */ -#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 + + .cstring +rwl_release_error_str: + .asciz "Releasing non-exclusive RW lock without a reader refcount!" + .text + +/* + * lck_rw_type_t lck_rw_done(lck_rw_t *) + * + */ +Entry(lck_rw_done) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and reader count */ + testl $(LCK_RW_INTERLOCK), %eax + jne 7f /* wait for interlock to clear */ + + movl %eax, %ecx /* keep original value in %eax for cmpxchgl */ + testl $(LCK_RW_SHARED_MASK), %ecx /* if reader count == 0, must be exclusive lock */ + je 2f + decl %ecx /* Decrement reader count */ + testl $(LCK_RW_SHARED_MASK), %ecx /* if reader count has now gone to 0, check for waiters */ + je 4f + jmp 6f +2: + testl $(LCK_RW_WANT_UPGRADE), %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) - pushl %edx /* push mutex address */ - call EXT(mutex_lock_wait) /* wait for the lock */ - addl $4,%esp - movl L_ARG0,%edx /* refetch lock pointer */ - jmp ml_retry /* and try again */ - -ENTRY2(mutex_try,_mutex_try) - FRAME + andl $(~LCK_RW_WANT_UPGRADE), %ecx + jmp 4f +3: + testl $(LCK_RW_WANT_WRITE), %ecx + je 8f /* lock is not 'owned', go panic */ + andl $(~LCK_RW_WANT_WRITE), %ecx +4: + /* + * test the original values to match what + * lck_rw_done_gen is going to do to determine + * which wakeups need to happen... + * + * if !(fake_lck->lck_rw_priv_excl && fake_lck->lck_w_waiting) + */ + testl $(LCK_W_WAITING), %eax + je 5f + andl $(~LCK_W_WAITING), %ecx -#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 */ + testl $(LCK_RW_PRIV_EXCL), %eax + jne 6f +5: + andl $(~LCK_R_WAITING), %ecx +6: + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 7f + +#if __i386__ + pushl %eax + push %edx + call EXT(lck_rw_done_gen) + addl $8, %esp +#else + mov %eax,%esi /* old flags in %rsi */ + /* lock is in %rdi already */ + call EXT(lck_rw_done_gen) +#endif + ret +7: + PAUSE + jmp 1b +8: + ALIGN_STACK() + LOAD_STRING_ARG0(rwl_release_error_str) + CALL_PANIC() + - movl L_ARG0,%edx /* fetch lock pointer */ + +/* + * lck_rw_type_t lck_rw_lock_exclusive_to_shared(lck_rw_t *) + * + */ +Entry(lck_rw_lock_exclusive_to_shared) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and reader count */ + testl $(LCK_RW_INTERLOCK), %eax + jne 6f /* wait for interlock to clear */ + + movl %eax, %ecx /* keep original value in %eax for cmpxchgl */ + incl %ecx /* Increment reader count */ + + testl $(LCK_RW_WANT_UPGRADE), %ecx + je 2f + andl $(~LCK_RW_WANT_UPGRADE), %ecx + jmp 3f +2: + andl $(~LCK_RW_WANT_WRITE), %ecx +3: + /* + * test the original values to match what + * lck_rw_lock_exclusive_to_shared_gen is going to do to determine + * which wakeups need to happen... + * + * if !(fake_lck->lck_rw_priv_excl && fake_lck->lck_w_waiting) + */ + testl $(LCK_W_WAITING), %eax + je 4f + testl $(LCK_RW_PRIV_EXCL), %eax + jne 5f +4: + andl $(~LCK_R_WAITING), %ecx +5: + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 6f + +#if __i386__ + pushl %eax + push %edx + call EXT(lck_rw_lock_exclusive_to_shared_gen) + addl $8, %esp +#else + mov %eax,%esi + call EXT(lck_rw_lock_exclusive_to_shared_gen) +#endif + ret +6: + PAUSE + jmp 1b - CHECK_MUTEX_TYPE() - CHECK_NO_SIMPLELOCKS() - xorl %eax,%eax - movb $1,%al /* locked value for mutex */ - xchgb %al,M_LOCKED /* swap locked values */ - xorb $1,%al /* generate return value */ -#if MACH_LDEBUG || ETAP_LOCK_TRACE - testl %eax,%eax /* did we succeed? */ - je 2f /* no, skip */ +/* + * int lck_rw_grab_want(lck_rw_t *) + * + */ +Entry(lck_rw_grab_want) + LOAD_LCK_RW_REGISTER +1: + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and reader count */ + testl $(LCK_RW_INTERLOCK), %eax + jne 3f /* wait for interlock to clear */ + testl $(LCK_RW_WANT_WRITE), %eax /* want_write has been grabbed by someone else */ + jne 2f /* go return failure */ + + movl %eax, %ecx /* original value in %eax for cmpxchgl */ + orl $(LCK_RW_WANT_WRITE), %ecx + lock + cmpxchgl %ecx, (LCK_RW_REGISTER) /* Attempt atomic exchange */ + jne 2f + /* we now own want_write */ + movl $1, %eax /* return success */ + ret +2: + xorl %eax, %eax /* return failure */ + ret +3: + PAUSE + jmp 1b + + +#define RW_LOCK_SHARED_OR_UPGRADE_MASK (LCK_RW_SHARED_MASK | LCK_RW_INTERLOCK | LCK_RW_WANT_UPGRADE) +/* + * int lck_rw_held_read_or_upgrade(lck_rw_t *) + * + */ +Entry(lck_rw_held_read_or_upgrade) + LOAD_LCK_RW_REGISTER + LOAD_LCK_RW_FLAGS_REGISTER /* Load state bitfield, interlock and reader count */ + andl $(RW_LOCK_SHARED_OR_UPGRADE_MASK), %eax + ret + + + +/* + * N.B.: On x86, statistics are currently recorded for all indirect mutexes. + * Also, only the acquire attempt count (GRP_MTX_STAT_UTIL) is maintained + * as a 64-bit quantity (this matches the existing PowerPC implementation, + * and the new x86 specific statistics are also maintained as 32-bit + * quantities). + * + * + * Enable this preprocessor define to record the first miss alone + * By default, we count every miss, hence multiple misses may be + * recorded for a single lock acquire attempt via lck_mtx_lock + */ +#undef LOG_FIRST_MISS_ALONE + +/* + * This preprocessor define controls whether the R-M-W update of the + * per-group statistics elements are atomic (LOCK-prefixed) + * Enabled by default. + */ +#define ATOMIC_STAT_UPDATES 1 + +#if defined(ATOMIC_STAT_UPDATES) +#define LOCK_IF_ATOMIC_STAT_UPDATES lock +#else +#define LOCK_IF_ATOMIC_STAT_UPDATES +#endif /* ATOMIC_STAT_UPDATES */ + + +/* + * For most routines, the lck_mtx_t pointer is loaded into a + * register initially, and the owner field checked for indirection. + * Eventually the lock owner is loaded into a register and examined. + */ + +#define M_OWNER MUTEX_OWNER +#define M_PTR MUTEX_PTR +#define M_STATE MUTEX_STATE + +#if defined(__i386__) + +#define LMTX_ARG0 B_ARG0 +#define LMTX_ARG1 B_ARG1 +#define LMTX_REG %edx +#define LMTX_A_REG %eax +#define LMTX_A_REG32 %eax +#define LMTX_C_REG %ecx +#define LMTX_C_REG32 %ecx +#define LMTX_RET_REG %eax +#define LMTX_RET_REG32 %eax +#define LMTX_LGROUP_REG %esi +#define LMTX_SSTATE_REG %edi +#define LOAD_LMTX_REG(arg) mov arg, LMTX_REG +#define LMTX_CHK_EXTENDED cmp LMTX_REG, LMTX_ARG0 +#define LMTX_ASSERT_OWNED cmpl $(MUTEX_ASSERT_OWNED), LMTX_ARG1 + +#define LMTX_ENTER_EXTENDED \ + mov M_PTR(LMTX_REG), LMTX_REG ; \ + push LMTX_LGROUP_REG ; \ + push LMTX_SSTATE_REG ; \ + xor LMTX_SSTATE_REG, LMTX_SSTATE_REG ; \ + mov MUTEX_GRP(LMTX_REG), LMTX_LGROUP_REG ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + addl $1, GRP_MTX_STAT_UTIL(LMTX_LGROUP_REG) ; \ + jnc 11f ; \ + incl GRP_MTX_STAT_UTIL+4(LMTX_LGROUP_REG) ; \ +11: + +#define LMTX_EXIT_EXTENDED \ + pop LMTX_SSTATE_REG ; \ + pop LMTX_LGROUP_REG + + +#define LMTX_CHK_EXTENDED_EXIT \ + cmp LMTX_REG, LMTX_ARG0 ; \ + je 12f ; \ + pop LMTX_SSTATE_REG ; \ + pop LMTX_LGROUP_REG ; \ +12: + + +#if LOG_FIRST_MISS_ALONE +#define LMTX_UPDATE_MISS \ + test $1, LMTX_SSTATE_REG ; \ + jnz 11f ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_MISS(LMTX_LGROUP_REG) ; \ + or $1, LMTX_SSTATE_REG ; \ +11: +#else +#define LMTX_UPDATE_MISS \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_MISS(LMTX_LGROUP_REG) #endif -#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 - -#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 */ - movl $1,%eax /* put back successful return value */ -#endif /* ETAP_LOCK_TRACE */ - -#if MACH_LDEBUG || ETAP_LOCK_TRACE -2: -#if ETAP_LOCK_TRACE - addl $8,%esp /* pop stack claimed on entry */ + +#if LOG_FIRST_MISS_ALONE +#define LMTX_UPDATE_WAIT \ + test $2, LMTX_SSTATE_REG ; \ + jnz 11f ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_WAIT(LMTX_LGROUP_REG) ; \ + or $2, LMTX_SSTATE_REG ; \ +11: +#else +#define LMTX_UPDATE_WAIT \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_WAIT(LMTX_LGROUP_REG) +#endif + + +/* + * Record the "direct wait" statistic, which indicates if a + * miss proceeded to block directly without spinning--occurs + * if the owner of the mutex isn't running on another processor + * at the time of the check. + */ +#define LMTX_UPDATE_DIRECT_WAIT \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_DIRECT_WAIT(LMTX_LGROUP_REG) + + +#define LMTX_CALLEXT1(func_name) \ + push LMTX_REG ; \ + push LMTX_REG ; \ + call EXT(func_name) ; \ + add $4, %esp ; \ + pop LMTX_REG + +#define LMTX_CALLEXT2(func_name, reg) \ + push LMTX_REG ; \ + push reg ; \ + push LMTX_REG ; \ + call EXT(func_name) ; \ + add $8, %esp ; \ + pop LMTX_REG + +#elif defined(__x86_64__) + +#define LMTX_ARG0 %rdi +#define LMTX_ARG1 %rsi +#define LMTX_REG_ORIG %rdi +#define LMTX_REG %rdx +#define LMTX_A_REG %rax +#define LMTX_A_REG32 %eax +#define LMTX_C_REG %rcx +#define LMTX_C_REG32 %ecx +#define LMTX_RET_REG %rax +#define LMTX_RET_REG32 %eax +#define LMTX_LGROUP_REG %r10 +#define LMTX_SSTATE_REG %r11 +#define LOAD_LMTX_REG(arg) mov %rdi, %rdx +#define LMTX_CHK_EXTENDED cmp LMTX_REG, LMTX_REG_ORIG +#define LMTX_ASSERT_OWNED cmp $(MUTEX_ASSERT_OWNED), LMTX_ARG1 + +#define LMTX_ENTER_EXTENDED \ + mov M_PTR(LMTX_REG), LMTX_REG ; \ + xor LMTX_SSTATE_REG, LMTX_SSTATE_REG ; \ + mov MUTEX_GRP(LMTX_REG), LMTX_LGROUP_REG ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incq GRP_MTX_STAT_UTIL(LMTX_LGROUP_REG) + +#define LMTX_EXIT_EXTENDED + +#define LMTX_CHK_EXTENDED_EXIT + + +#if LOG_FIRST_MISS_ALONE +#define LMTX_UPDATE_MISS \ + test $1, LMTX_SSTATE_REG ; \ + jnz 11f ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_MISS(LMTX_LGROUP_REG) ; \ + or $1, LMTX_SSTATE_REG ; \ +11: +#else +#define LMTX_UPDATE_MISS \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_MISS(LMTX_LGROUP_REG) #endif + + +#if LOG_FIRST_MISS_ALONE +#define LMTX_UPDATE_WAIT \ + test $2, LMTX_SSTATE_REG ; \ + jnz 11f ; \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_WAIT(LMTX_LGROUP_REG) ; \ + or $2, LMTX_SSTATE_REG ; \ +11: +#else +#define LMTX_UPDATE_WAIT \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_WAIT(LMTX_LGROUP_REG) +#endif + + +/* + * Record the "direct wait" statistic, which indicates if a + * miss proceeded to block directly without spinning--occurs + * if the owner of the mutex isn't running on another processor + * at the time of the check. + */ +#define LMTX_UPDATE_DIRECT_WAIT \ + LOCK_IF_ATOMIC_STAT_UPDATES ; \ + incl GRP_MTX_STAT_DIRECT_WAIT(LMTX_LGROUP_REG) + + +#define LMTX_CALLEXT1(func_name) \ + LMTX_CHK_EXTENDED ; \ + je 12f ; \ + push LMTX_LGROUP_REG ; \ + push LMTX_SSTATE_REG ; \ +12: push LMTX_REG_ORIG ; \ + push LMTX_REG ; \ + mov LMTX_REG, LMTX_ARG0 ; \ + call EXT(func_name) ; \ + pop LMTX_REG ; \ + pop LMTX_REG_ORIG ; \ + LMTX_CHK_EXTENDED ; \ + je 12f ; \ + pop LMTX_SSTATE_REG ; \ + pop LMTX_LGROUP_REG ; \ +12: + +#define LMTX_CALLEXT2(func_name, reg) \ + LMTX_CHK_EXTENDED ; \ + je 12f ; \ + push LMTX_LGROUP_REG ; \ + push LMTX_SSTATE_REG ; \ +12: push LMTX_REG_ORIG ; \ + push LMTX_REG ; \ + mov reg, LMTX_ARG1 ; \ + mov LMTX_REG, LMTX_ARG0 ; \ + call EXT(func_name) ; \ + pop LMTX_REG ; \ + pop LMTX_REG_ORIG ; \ + LMTX_CHK_EXTENDED ; \ + je 12f ; \ + pop LMTX_SSTATE_REG ; \ + pop LMTX_LGROUP_REG ; \ +12: + +#else +#error Unsupported architecture #endif - EMARF + +#define M_WAITERS_MSK 0x0000ffff +#define M_PRIORITY_MSK 0x00ff0000 +#define M_ILOCKED_MSK 0x01000000 +#define M_MLOCKED_MSK 0x02000000 +#define M_PROMOTED_MSK 0x04000000 +#define M_SPIN_MSK 0x08000000 + +/* + * void lck_mtx_assert(lck_mtx_t* l, unsigned int) + * Takes the address of a lock, and an assertion type as parameters. + * The assertion can take one of two forms determine by the type + * parameter: either the lock is held by the current thread, and the + * type is LCK_MTX_ASSERT_OWNED, or it isn't and the type is + * LCK_MTX_ASSERT_NOTOWNED. Calls panic on assertion failure. + * + */ + +NONLEAF_ENTRY(lck_mtx_assert) + LOAD_LMTX_REG(B_ARG0) /* Load lock address */ + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG /* Load current thread */ + + mov M_STATE(LMTX_REG), LMTX_C_REG32 + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne 0f + mov M_PTR(LMTX_REG), LMTX_REG /* If so, take indirection */ +0: + mov M_OWNER(LMTX_REG), LMTX_C_REG /* Load owner */ + LMTX_ASSERT_OWNED + jne 2f /* Assert ownership? */ + cmp LMTX_A_REG, LMTX_C_REG /* Current thread match? */ + jne 3f /* no, go panic */ + testl $(M_ILOCKED_MSK | M_MLOCKED_MSK), M_STATE(LMTX_REG) + je 3f +1: /* yes, we own it */ + NONLEAF_RET +2: + cmp LMTX_A_REG, LMTX_C_REG /* Current thread match? */ + jne 1b /* No, return */ + ALIGN_STACK() + LOAD_PTR_ARG1(LMTX_REG) + LOAD_STRING_ARG0(mutex_assert_owned_str) + jmp 4f +3: + ALIGN_STACK() + LOAD_PTR_ARG1(LMTX_REG) + LOAD_STRING_ARG0(mutex_assert_not_owned_str) +4: + CALL_PANIC() + + +lck_mtx_destroyed: + ALIGN_STACK() + LOAD_PTR_ARG1(LMTX_REG) + LOAD_STRING_ARG0(mutex_interlock_destroyed_str) + CALL_PANIC() + + +.data +mutex_assert_not_owned_str: + .asciz "mutex (%p) not owned\n" +mutex_assert_owned_str: + .asciz "mutex (%p) owned\n" +mutex_interlock_destroyed_str: + .asciz "trying to interlock destroyed mutex (%p)" +.text + + + +/* + * lck_mtx_lock() + * lck_mtx_try_lock() + * lck_mtx_unlock() + * lck_mtx_lock_spin() + * lck_mtx_lock_spin_always() + * lck_mtx_convert_spin() + */ +NONLEAF_ENTRY(lck_mtx_lock_spin_always) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + jmp Llmls_avoid_check + +NONLEAF_ENTRY(lck_mtx_lock_spin) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + + CHECK_PREEMPTION_LEVEL() +Llmls_avoid_check: + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 /* is the interlock or mutex held */ + jnz Llmls_slow +Llmls_try: /* no - can't be INDIRECT, DESTROYED or locked */ + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK | M_SPIN_MSK), LMTX_C_REG32 + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne Llmls_busy_disabled + + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of interlock */ +#if MACH_LDEBUG + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + + LMTX_CHK_EXTENDED_EXIT + /* return with the interlock held and preemption disabled */ + leave +#if CONFIG_DTRACE + LOCKSTAT_LABEL(_lck_mtx_lock_spin_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG above */ + LOCKSTAT_RECORD(LS_LCK_MTX_LOCK_SPIN_ACQUIRE, LMTX_REG) +#endif ret -ENTRY(mutex_unlock) - FRAME - movl L_ARG0,%edx /* fetch lock pointer */ +Llmls_slow: + test $M_ILOCKED_MSK, LMTX_C_REG32 /* is the interlock held */ + jz Llml_contended /* no, must have been the mutex */ + + cmp $(MUTEX_DESTROYED), LMTX_C_REG32 /* check to see if its marked destroyed */ + je lck_mtx_destroyed + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex */ + jne Llmls_loop /* no... must be interlocked */ + + LMTX_ENTER_EXTENDED -#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 */ + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_SPIN_MSK), LMTX_C_REG32 + jz Llmls_loop1 - CHECK_MUTEX_TYPE() - CHECK_THREAD(M_THREAD) + LMTX_UPDATE_MISS /* M_SPIN_MSK was set, so M_ILOCKED_MSK must also be present */ +Llmls_loop: + PAUSE + mov M_STATE(LMTX_REG), LMTX_C_REG32 +Llmls_loop1: + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 + jz Llmls_try + test $(M_MLOCKED_MSK), LMTX_C_REG32 + jnz Llml_contended /* mutex owned by someone else, go contend for it */ + jmp Llmls_loop - DISABLE_PREEMPTION(%eax) +Llmls_busy_disabled: + PREEMPTION_ENABLE + jmp Llmls_loop + + + +NONLEAF_ENTRY(lck_mtx_lock) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + + CHECK_PREEMPTION_LEVEL() -mu_get_hw: - movb $1,%cl - xchgb %cl,M_ILK - testb %cl,%cl /* did we succeed? */ - jne mu_get_hw /* no, try again */ + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 /* is the interlock or mutex held */ + jnz Llml_slow +Llml_try: /* no - can't be INDIRECT, DESTROYED or locked */ + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 - cmpw $0,M_WAITERS /* are there any waiters? */ - jne mu_wakeup /* yes, more work to do */ + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne Llml_busy_disabled -mu_doit: + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of mutex */ #if MACH_LDEBUG - xorl %eax,%eax - movl %eax,M_THREAD /* disown thread */ - movl $CPD_ACTIVE_THREAD,%eax - movl %gs:(%eax),%ecx - testl %ecx,%ecx + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + + testl $(M_WAITERS_MSK), M_STATE(LMTX_REG) + jz Llml_finish + + LMTX_CALLEXT1(lck_mtx_lock_acquire_x86) + +Llml_finish: + andl $(~M_ILOCKED_MSK), M_STATE(LMTX_REG) + PREEMPTION_ENABLE + + LMTX_CHK_EXTENDED /* is this an extended mutex */ + jne 2f + + leave +#if CONFIG_DTRACE + LOCKSTAT_LABEL(_lck_mtx_lock_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG above */ + LOCKSTAT_RECORD(LS_LCK_MTX_LOCK_ACQUIRE, LMTX_REG) +#endif + ret +2: + LMTX_EXIT_EXTENDED + leave +#if CONFIG_DTRACE + LOCKSTAT_LABEL(_lck_mtx_lock_ext_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG above */ + LOCKSTAT_RECORD(LS_LCK_MTX_EXT_LOCK_ACQUIRE, LMTX_REG) +#endif + ret + + +Llml_slow: + test $M_ILOCKED_MSK, LMTX_C_REG32 /* is the interlock held */ + jz Llml_contended /* no, must have been the mutex */ + + cmp $(MUTEX_DESTROYED), LMTX_C_REG32 /* check to see if its marked destroyed */ + je lck_mtx_destroyed + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne Llml_loop /* no... must be interlocked */ + + LMTX_ENTER_EXTENDED + + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_SPIN_MSK), LMTX_C_REG32 + jz Llml_loop1 + + LMTX_UPDATE_MISS /* M_SPIN_MSK was set, so M_ILOCKED_MSK must also be present */ +Llml_loop: + PAUSE + mov M_STATE(LMTX_REG), LMTX_C_REG32 +Llml_loop1: + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 + jz Llml_try + test $(M_MLOCKED_MSK), LMTX_C_REG32 + jnz Llml_contended /* mutex owned by someone else, go contend for it */ + jmp Llml_loop + +Llml_busy_disabled: + PREEMPTION_ENABLE + jmp Llml_loop + + +Llml_contended: + LMTX_CHK_EXTENDED /* is this an extended mutex */ je 0f - decl TH_MUTEX_COUNT(%ecx) -0: + LMTX_UPDATE_MISS +0: + LMTX_CALLEXT1(lck_mtx_lock_spinwait_x86) + + test LMTX_RET_REG, LMTX_RET_REG + jz Llml_acquired /* acquired mutex, interlock held and preemption disabled */ + + cmp $1, LMTX_RET_REG /* check for direct wait status */ + je 2f + LMTX_CHK_EXTENDED /* is this an extended mutex */ + je 2f + LMTX_UPDATE_DIRECT_WAIT +2: + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_ILOCKED_MSK), LMTX_C_REG32 + jnz 6f + + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK), LMTX_C_REG32 /* try to take the interlock */ + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne 5f + + test $(M_MLOCKED_MSK), LMTX_C_REG32 /* we've got the interlock and */ + jnz 3f + or $(M_MLOCKED_MSK), LMTX_C_REG32 /* the mutex is free... grab it directly */ + mov LMTX_C_REG32, M_STATE(LMTX_REG) + + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of mutex */ +#if MACH_LDEBUG + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + +Llml_acquired: + testl $(M_WAITERS_MSK), M_STATE(LMTX_REG) + jnz 1f + mov M_OWNER(LMTX_REG), LMTX_A_REG + mov TH_WAS_PROMOTED_ON_WAKEUP(LMTX_A_REG), LMTX_A_REG32 + test LMTX_A_REG32, LMTX_A_REG32 + jz Llml_finish +1: + LMTX_CALLEXT1(lck_mtx_lock_acquire_x86) + jmp Llml_finish + +3: /* interlock held, mutex busy */ + LMTX_CHK_EXTENDED /* is this an extended mutex */ + je 4f + LMTX_UPDATE_WAIT +4: + LMTX_CALLEXT1(lck_mtx_lock_wait_x86) + jmp Llml_contended +5: + PREEMPTION_ENABLE +6: + PAUSE + jmp 2b + + + +NONLEAF_ENTRY(lck_mtx_try_lock_spin) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 /* is the interlock or mutex held */ + jnz Llmts_slow +Llmts_try: /* no - can't be INDIRECT, DESTROYED or locked */ + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK | M_SPIN_MSK), LMTX_C_REG + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne Llmts_busy_disabled + + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of mutex */ +#if MACH_LDEBUG + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + + LMTX_CHK_EXTENDED_EXIT + leave + +#if CONFIG_DTRACE + mov $1, LMTX_RET_REG /* return success */ + LOCKSTAT_LABEL(_lck_mtx_try_lock_spin_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG above */ + LOCKSTAT_RECORD(LS_LCK_MTX_TRY_SPIN_LOCK_ACQUIRE, LMTX_REG) #endif + mov $1, LMTX_RET_REG /* return success */ + ret - xorb %cl,%cl - xchgb %cl,M_LOCKED /* unlock the mutex */ +Llmts_slow: + test $(M_ILOCKED_MSK), LMTX_C_REG32 /* is the interlock held */ + jz Llmts_fail /* no, must be held as a mutex */ + + cmp $(MUTEX_DESTROYED), LMTX_C_REG32 /* check to see if its marked destroyed */ + je lck_mtx_destroyed + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne Llmts_loop1 + + LMTX_ENTER_EXTENDED +Llmts_loop: + PAUSE + mov M_STATE(LMTX_REG), LMTX_C_REG32 +Llmts_loop1: + test $(M_MLOCKED_MSK | M_SPIN_MSK), LMTX_C_REG32 + jnz Llmts_fail + test $(M_ILOCKED_MSK), LMTX_C_REG32 + jz Llmts_try + jmp Llmts_loop + +Llmts_busy_disabled: + PREEMPTION_ENABLE + jmp Llmts_loop - xorb %cl,%cl - xchgb %cl,M_ILK - ENABLE_PREEMPTION(%eax) + +NONLEAF_ENTRY(lck_mtx_try_lock) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + + mov M_STATE(LMTX_REG), LMTX_C_REG32 + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 /* is the interlock or mutex held */ + jnz Llmt_slow +Llmt_try: /* no - can't be INDIRECT, DESTROYED or locked */ + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne Llmt_busy_disabled + + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of mutex */ +#if MACH_LDEBUG + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ - EMARF + LMTX_CHK_EXTENDED_EXIT + + test $(M_WAITERS_MSK), LMTX_C_REG32 + jz 0f + + LMTX_CALLEXT1(lck_mtx_lock_acquire_x86) +0: + andl $(~M_ILOCKED_MSK), M_STATE(LMTX_REG) + PREEMPTION_ENABLE + + leave +#if CONFIG_DTRACE + mov $1, LMTX_RET_REG /* return success */ + /* Dtrace probe: LS_LCK_MTX_TRY_LOCK_ACQUIRE */ + LOCKSTAT_LABEL(_lck_mtx_try_lock_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG from above */ + LOCKSTAT_RECORD(LS_LCK_MTX_TRY_LOCK_ACQUIRE, LMTX_REG) +#endif + mov $1, LMTX_RET_REG /* return success */ ret -mu_wakeup: - pushl %edx /* push mutex address */ - call EXT(mutex_unlock_wakeup)/* yes, wake a thread */ - addl $4,%esp - movl L_ARG0,%edx /* refetch lock pointer */ - jmp mu_doit +Llmt_slow: + test $(M_ILOCKED_MSK), LMTX_C_REG32 /* is the interlock held */ + jz Llmt_fail /* no, must be held as a mutex */ + + cmp $(MUTEX_DESTROYED), LMTX_C_REG32 /* check to see if its marked destroyed */ + je lck_mtx_destroyed + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne Llmt_loop + + LMTX_ENTER_EXTENDED +Llmt_loop: + PAUSE + mov M_STATE(LMTX_REG), LMTX_C_REG32 +Llmt_loop1: + test $(M_MLOCKED_MSK | M_SPIN_MSK), LMTX_C_REG32 + jnz Llmt_fail + test $(M_ILOCKED_MSK), LMTX_C_REG32 + jz Llmt_try + jmp Llmt_loop + +Llmt_busy_disabled: + PREEMPTION_ENABLE + jmp Llmt_loop + + +Llmt_fail: +Llmts_fail: + LMTX_CHK_EXTENDED /* is this an extended mutex */ + je 0f + LMTX_UPDATE_MISS + LMTX_EXIT_EXTENDED +0: + xor LMTX_RET_REG, LMTX_RET_REG + NONLEAF_RET -ENTRY(interlock_unlock) - FRAME - movl L_ARG0,%edx - xorb %cl,%cl - xchgb %cl,M_ILK - ENABLE_PREEMPTION(%eax) +NONLEAF_ENTRY(lck_mtx_convert_spin) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ - EMARF + mov M_STATE(LMTX_REG), LMTX_C_REG32 + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne 0f + mov M_PTR(LMTX_REG), LMTX_REG /* If so, take indirection */ + mov M_STATE(LMTX_REG), LMTX_C_REG32 +0: + test $(M_MLOCKED_MSK), LMTX_C_REG32 /* already owned as a mutex, just return */ + jnz 2f + test $(M_WAITERS_MSK), LMTX_C_REG32 /* are there any waiters? */ + jz 1f + + LMTX_CALLEXT1(lck_mtx_lock_acquire_x86) + mov M_STATE(LMTX_REG), LMTX_C_REG32 +1: + and $(~(M_ILOCKED_MSK | M_SPIN_MSK)), LMTX_C_REG32 /* convert from spin version to mutex */ + or $(M_MLOCKED_MSK), LMTX_C_REG32 + mov LMTX_C_REG32, M_STATE(LMTX_REG) /* since I own the interlock, I don't need an atomic update */ + + PREEMPTION_ENABLE +2: + NONLEAF_RET + + + +#if defined(__i386__) +NONLEAF_ENTRY(lck_mtx_unlock) + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ + mov M_OWNER(LMTX_REG), LMTX_A_REG + test LMTX_A_REG, LMTX_A_REG + jnz Llmu_entry + leave ret +NONLEAF_ENTRY(lck_mtx_unlock_darwin10) +#else +NONLEAF_ENTRY(lck_mtx_unlock) +#endif + LOAD_LMTX_REG(B_ARG0) /* fetch lock pointer */ +Llmu_entry: + mov M_STATE(LMTX_REG), LMTX_C_REG32 +Llmu_prim: + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + je Llmu_ext + +Llmu_chktype: + test $(M_MLOCKED_MSK), LMTX_C_REG32 /* check for full mutex */ + jz Llmu_unlock +Llmu_mutex: + test $(M_ILOCKED_MSK), LMTX_C_REG /* have to wait for interlock to clear */ + jnz Llmu_busy + + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + and $(~M_MLOCKED_MSK), LMTX_C_REG32 /* drop mutex */ + or $(M_ILOCKED_MSK), LMTX_C_REG32 /* pick up interlock */ + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne Llmu_busy_disabled /* branch on failure to spin loop */ + +Llmu_unlock: + xor LMTX_A_REG, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) + mov LMTX_C_REG, LMTX_A_REG /* keep original state in %ecx for later evaluation */ + and $(~(M_ILOCKED_MSK | M_SPIN_MSK | M_PROMOTED_MSK)), LMTX_A_REG + + test $(M_WAITERS_MSK), LMTX_A_REG32 + jz 2f + dec LMTX_A_REG32 /* decrement waiter count */ +2: + mov LMTX_A_REG32, M_STATE(LMTX_REG) /* since I own the interlock, I don't need an atomic update */ + +#if MACH_LDEBUG + /* perform lock statistics after drop to prevent delay */ + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + test LMTX_A_REG, LMTX_A_REG + jz 1f + decl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + + test $(M_PROMOTED_MSK | M_WAITERS_MSK), LMTX_C_REG32 + jz 3f + + LMTX_CALLEXT2(lck_mtx_unlock_wakeup_x86, LMTX_C_REG) +3: + PREEMPTION_ENABLE + + LMTX_CHK_EXTENDED + jne 4f + + leave +#if CONFIG_DTRACE + /* Dtrace: LS_LCK_MTX_UNLOCK_RELEASE */ + LOCKSTAT_LABEL(_lck_mtx_unlock_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG from above */ + LOCKSTAT_RECORD(LS_LCK_MTX_UNLOCK_RELEASE, LMTX_REG) +#endif + ret +4: + leave +#if CONFIG_DTRACE + /* Dtrace: LS_LCK_MTX_EXT_UNLOCK_RELEASE */ + LOCKSTAT_LABEL(_lck_mtx_ext_unlock_lockstat_patch_point) + ret + /* inherit lock pointer in LMTX_REG from above */ + LOCKSTAT_RECORD(LS_LCK_MTX_EXT_UNLOCK_RELEASE, LMTX_REG) +#endif + ret + + +Llmu_busy_disabled: + PREEMPTION_ENABLE +Llmu_busy: + PAUSE + mov M_STATE(LMTX_REG), LMTX_C_REG32 + jmp Llmu_mutex + +Llmu_ext: + mov M_PTR(LMTX_REG), LMTX_REG + mov M_OWNER(LMTX_REG), LMTX_A_REG + mov %gs:CPU_ACTIVE_THREAD, LMTX_C_REG + CHECK_UNLOCK(LMTX_C_REG, LMTX_A_REG) + mov M_STATE(LMTX_REG), LMTX_C_REG32 + jmp Llmu_chktype + + + +LEAF_ENTRY(lck_mtx_ilk_unlock) + LOAD_LMTX_REG(L_ARG0) /* fetch lock pointer - no indirection here */ + + andl $(~M_ILOCKED_MSK), M_STATE(LMTX_REG) + + PREEMPTION_ENABLE /* need to re-enable preemption */ + + LEAF_RET + -ENTRY(_disable_preemption) +LEAF_ENTRY(lck_mtx_lock_grab_mutex) + LOAD_LMTX_REG(L_ARG0) /* fetch lock pointer - no indirection here */ + + mov M_STATE(LMTX_REG), LMTX_C_REG32 + + test $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 /* can't have the mutex yet */ + jnz 3f + + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK | M_MLOCKED_MSK), LMTX_C_REG32 + + PREEMPTION_DISABLE + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne 2f /* branch on failure to spin loop */ + + mov %gs:CPU_ACTIVE_THREAD, LMTX_A_REG + mov LMTX_A_REG, M_OWNER(LMTX_REG) /* record owner of mutex */ +#if MACH_LDEBUG + test LMTX_A_REG, LMTX_A_REG + jz 1f + incl TH_MUTEX_COUNT(LMTX_A_REG) /* lock statistic */ +1: +#endif /* MACH_LDEBUG */ + + mov $1, LMTX_RET_REG /* return success */ + LEAF_RET +2: + PREEMPTION_ENABLE +3: + xor LMTX_RET_REG, LMTX_RET_REG /* return failure */ + LEAF_RET + + + +LEAF_ENTRY(lck_mtx_lock_mark_destroyed) + LOAD_LMTX_REG(L_ARG0) +1: + mov M_STATE(LMTX_REG), LMTX_C_REG32 + cmp $(MUTEX_IND), LMTX_C_REG32 /* Is this an indirect mutex? */ + jne 2f + + movl $(MUTEX_DESTROYED), M_STATE(LMTX_REG) /* convert to destroyed state */ + jmp 3f +2: + test $(M_ILOCKED_MSK), LMTX_C_REG /* have to wait for interlock to clear */ + jnz 5f + + PREEMPTION_DISABLE + mov LMTX_C_REG, LMTX_A_REG /* eax contains snapshot for cmpxchgl */ + or $(M_ILOCKED_MSK), LMTX_C_REG32 + lock + cmpxchg LMTX_C_REG32, M_STATE(LMTX_REG) /* atomic compare and exchange */ + jne 4f /* branch on failure to spin loop */ + movl $(MUTEX_DESTROYED), M_STATE(LMTX_REG) /* convert to destroyed state */ + PREEMPTION_ENABLE +3: + LEAF_RET /* return with M_ILOCKED set */ +4: + PREEMPTION_ENABLE +5: + PAUSE + jmp 1b + +LEAF_ENTRY(preemption_underflow_panic) + FRAME + incl %gs:CPU_PREEMPTION_LEVEL + ALIGN_STACK() + LOAD_STRING_ARG0(16f) + CALL_PANIC() + hlt + .data +16: String "Preemption level underflow, possible cause unlocking an unlocked mutex or spinlock" + .text + + +LEAF_ENTRY(_disable_preemption) #if MACH_RT - _DISABLE_PREEMPTION(%eax) + PREEMPTION_DISABLE #endif /* MACH_RT */ - ret + LEAF_RET -ENTRY(_enable_preemption) +LEAF_ENTRY(_enable_preemption) #if MACH_RT #if MACH_ASSERT - movl $CPD_PREEMPTION_LEVEL,%eax - cmpl $0,%gs:(%eax) + cmpl $0,%gs:CPU_PREEMPTION_LEVEL jg 1f - pushl %gs:(%eax) - pushl $2f - call EXT(panic) +#if __i386__ + pushl %gs:CPU_PREEMPTION_LEVEL +#else + movl %gs:CPU_PREEMPTION_LEVEL,%esi +#endif + ALIGN_STACK() + LOAD_STRING_ARG0(_enable_preemption_less_than_zero) + CALL_PANIC() hlt - .data -2: String "_enable_preemption: preemption_level(%d) < 0!" + .cstring +_enable_preemption_less_than_zero: + .asciz "_enable_preemption: preemption_level(%d) < 0!" .text 1: #endif /* MACH_ASSERT */ - _ENABLE_PREEMPTION(%eax) + PREEMPTION_ENABLE #endif /* MACH_RT */ - ret + LEAF_RET -ENTRY(_enable_preemption_no_check) +LEAF_ENTRY(_enable_preemption_no_check) #if MACH_RT #if MACH_ASSERT - movl $CPD_PREEMPTION_LEVEL,%eax - cmpl $0,%gs:(%eax) + cmpl $0,%gs:CPU_PREEMPTION_LEVEL jg 1f - pushl $2f - call EXT(panic) + ALIGN_STACK() + LOAD_STRING_ARG0(_enable_preemption_no_check_less_than_zero) + CALL_PANIC() hlt - .data -2: String "_enable_preemption_no_check: preemption_level <= 0!" + .cstring +_enable_preemption_no_check_less_than_zero: + .asciz "_enable_preemption_no_check: preemption_level <= 0!" .text 1: #endif /* MACH_ASSERT */ - _ENABLE_PREEMPTION_NO_CHECK(%eax) + _ENABLE_PREEMPTION_NO_CHECK #endif /* MACH_RT */ - ret + LEAF_RET -ENTRY(_mp_disable_preemption) -#if MACH_RT && NCPUS > 1 - _DISABLE_PREEMPTION(%eax) -#endif /* MACH_RT && NCPUS > 1*/ - ret +LEAF_ENTRY(_mp_disable_preemption) +#if MACH_RT + PREEMPTION_DISABLE +#endif /* MACH_RT */ + LEAF_RET -ENTRY(_mp_enable_preemption) -#if MACH_RT && NCPUS > 1 +LEAF_ENTRY(_mp_enable_preemption) +#if MACH_RT #if MACH_ASSERT - movl $CPD_PREEMPTION_LEVEL,%eax - cmpl $0,%gs:(%eax) + cmpl $0,%gs:CPU_PREEMPTION_LEVEL jg 1f - pushl %gs:(%eax) - pushl $2f - call EXT(panic) +#if __i386__ + pushl %gs:CPU_PREEMPTION_LEVEL +#else + movl %gs:CPU_PREEMPTION_LEVEL,%esi +#endif + ALIGN_PANIC() + LOAD_STRING_ARG0(_mp_enable_preemption_less_than_zero) + CALL_PANIC() hlt - .data -2: String "_mp_enable_preemption: preemption_level (%d) <= 0!" + .cstring +_mp_enable_preemption_less_than_zero: + .asciz "_mp_enable_preemption: preemption_level (%d) <= 0!" .text 1: #endif /* MACH_ASSERT */ - _ENABLE_PREEMPTION(%eax) -#endif /* MACH_RT && NCPUS > 1 */ - ret + PREEMPTION_ENABLE +#endif /* MACH_RT */ + LEAF_RET -ENTRY(_mp_enable_preemption_no_check) -#if MACH_RT && NCPUS > 1 +LEAF_ENTRY(_mp_enable_preemption_no_check) +#if MACH_RT #if MACH_ASSERT - movl $CPD_PREEMPTION_LEVEL,%eax - cmpl $0,%gs:(%eax) + cmpl $0,%gs:CPU_PREEMPTION_LEVEL jg 1f - pushl $2f - call EXT(panic) + ALIGN_STACK() + LOAD_STRING_ARG0(_mp_enable_preemption_no_check_less_than_zero) + CALL_PANIC() hlt - .data -2: String "_mp_enable_preemption_no_check: preemption_level <= 0!" + .cstring +_mp_enable_preemption_no_check_less_than_zero: + .asciz "_mp_enable_preemption_no_check: preemption_level <= 0!" .text 1: #endif /* MACH_ASSERT */ - _ENABLE_PREEMPTION_NO_CHECK(%eax) -#endif /* MACH_RT && NCPUS > 1 */ - ret + _ENABLE_PREEMPTION_NO_CHECK +#endif /* MACH_RT */ + LEAF_RET +#if __i386__ -ENTRY(i_bit_set) - movl S_ARG0,%edx - movl S_ARG1,%eax +LEAF_ENTRY(i_bit_set) + movl L_ARG0,%edx + movl L_ARG1,%eax lock - bts %dl,(%eax) - ret + bts %edx,(%eax) + LEAF_RET -ENTRY(i_bit_clear) - movl S_ARG0,%edx - movl S_ARG1,%eax +LEAF_ENTRY(i_bit_clear) + movl L_ARG0,%edx + movl L_ARG1,%eax lock - btr %dl,(%eax) - ret + btr %edx,(%eax) + LEAF_RET + -ENTRY(bit_lock) - movl S_ARG0,%ecx - movl S_ARG1,%eax +LEAF_ENTRY(bit_lock) + movl L_ARG0,%ecx + movl L_ARG1,%eax 1: lock bts %ecx,(%eax) jb 1b - ret + LEAF_RET + -ENTRY(bit_lock_try) - movl S_ARG0,%ecx - movl S_ARG1,%eax +LEAF_ENTRY(bit_lock_try) + movl L_ARG0,%ecx + movl L_ARG1,%eax lock bts %ecx,(%eax) jb bit_lock_failed - ret /* %eax better not be null ! */ + LEAF_RET /* %eax better not be null ! */ bit_lock_failed: xorl %eax,%eax - ret + LEAF_RET -ENTRY(bit_unlock) - movl S_ARG0,%ecx - movl S_ARG1,%eax +LEAF_ENTRY(bit_unlock) + movl L_ARG0,%ecx + movl L_ARG1,%eax lock btr %ecx,(%eax) - ret + LEAF_RET + +/* + * Atomic primitives, prototyped in kern/simple_lock.h + */ +LEAF_ENTRY(hw_atomic_add) + movl L_ARG0, %ecx /* Load address of operand */ + movl L_ARG1, %eax /* Load addend */ + movl %eax, %edx + lock + xaddl %eax, (%ecx) /* Atomic exchange and add */ + addl %edx, %eax /* Calculate result */ + LEAF_RET + +LEAF_ENTRY(hw_atomic_sub) + movl L_ARG0, %ecx /* Load address of operand */ + movl L_ARG1, %eax /* Load subtrahend */ + negl %eax + movl %eax, %edx + lock + xaddl %eax, (%ecx) /* Atomic exchange and add */ + addl %edx, %eax /* Calculate result */ + LEAF_RET + +LEAF_ENTRY(hw_atomic_or) + movl L_ARG0, %ecx /* Load address of operand */ + movl (%ecx), %eax +1: + movl L_ARG1, %edx /* Load mask */ + orl %eax, %edx + lock + cmpxchgl %edx, (%ecx) /* Atomic CAS */ + jne 1b + movl %edx, %eax /* Result */ + LEAF_RET +/* + * A variant of hw_atomic_or which doesn't return a value. + * The implementation is thus comparatively more efficient. + */ + +LEAF_ENTRY(hw_atomic_or_noret) + movl L_ARG0, %ecx /* Load address of operand */ + movl L_ARG1, %edx /* Load mask */ + lock + orl %edx, (%ecx) /* Atomic OR */ + LEAF_RET + +LEAF_ENTRY(hw_atomic_and) + movl L_ARG0, %ecx /* Load address of operand */ + movl (%ecx), %eax +1: + movl L_ARG1, %edx /* Load mask */ + andl %eax, %edx + lock + cmpxchgl %edx, (%ecx) /* Atomic CAS */ + jne 1b + movl %edx, %eax /* Result */ + LEAF_RET +/* + * A variant of hw_atomic_and which doesn't return a value. + * The implementation is thus comparatively more efficient. + */ + +LEAF_ENTRY(hw_atomic_and_noret) + movl L_ARG0, %ecx /* Load address of operand */ + movl L_ARG1, %edx /* Load mask */ + lock + andl %edx, (%ecx) /* Atomic AND */ + LEAF_RET + +#else /* !__i386__ */ + +LEAF_ENTRY(i_bit_set) + lock + bts %edi,(%rsi) + LEAF_RET + +LEAF_ENTRY(i_bit_clear) + lock + btr %edi,(%rsi) + LEAF_RET + + +LEAF_ENTRY(bit_lock) +1: + lock + bts %edi,(%rsi) + jb 1b + LEAF_RET + + +LEAF_ENTRY(bit_lock_try) + lock + bts %edi,(%rsi) + jb bit_lock_failed + movl $1, %eax + LEAF_RET +bit_lock_failed: + xorl %eax,%eax + LEAF_RET + +LEAF_ENTRY(bit_unlock) + lock + btr %edi,(%rsi) + LEAF_RET + + +/* + * Atomic primitives, prototyped in kern/simple_lock.h + */ +LEAF_ENTRY(hw_atomic_add) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + movl %esi, %eax /* Load addend */ + lock xaddl %eax, (%rdi) /* Atomic exchange and add */ + addl %esi, %eax /* Calculate result */ + LEAF_RET + +LEAF_ENTRY(hw_atomic_sub) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + negl %esi + movl %esi, %eax + lock xaddl %eax, (%rdi) /* Atomic exchange and add */ + addl %esi, %eax /* Calculate result */ + LEAF_RET + +LEAF_ENTRY(hw_atomic_or) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + movl (%rdi), %eax +1: + movl %esi, %edx /* Load mask */ + orl %eax, %edx + lock cmpxchgl %edx, (%rdi) /* Atomic CAS */ + jne 1b + movl %edx, %eax /* Result */ + LEAF_RET +/* + * A variant of hw_atomic_or which doesn't return a value. + * The implementation is thus comparatively more efficient. + */ + +LEAF_ENTRY(hw_atomic_or_noret) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + lock + orl %esi, (%rdi) /* Atomic OR */ + LEAF_RET + + +LEAF_ENTRY(hw_atomic_and) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + movl (%rdi), %eax +1: + movl %esi, %edx /* Load mask */ + andl %eax, %edx + lock cmpxchgl %edx, (%rdi) /* Atomic CAS */ + jne 1b + movl %edx, %eax /* Result */ + LEAF_RET +/* + * A variant of hw_atomic_and which doesn't return a value. + * The implementation is thus comparatively more efficient. + */ + +LEAF_ENTRY(hw_atomic_and_noret) +#if MACH_LDEBUG + test $3, %rdi + jz 1f + ud2 +1: +#endif + lock andl %esi, (%rdi) /* Atomic OR */ + LEAF_RET + +#endif /* !__i386 __ */