* the terms and conditions for use and redistribution.
*/
-#include <mach_rt.h>
#include <mach_ldebug.h>
#include <i386/asm.h>
#include <i386/eflags.h>
#include <i386/trap.h>
#include <config_dtrace.h>
#include <i386/mp.h>
-
+
#include "assym.s"
#define PAUSE rep; nop
#define LEAF_ENTRY(name) \
Entry(name)
-#define LEAF_ENTRY2(n1,n2) \
- Entry(n1); \
- Entry(n2)
-
#define LEAF_RET \
ret
-/* Non-leaf routines always have a stack frame: */
-
-#define NONLEAF_ENTRY(name) \
- Entry(name); \
- FRAME
-
-#define NONLEAF_ENTRY2(n1,n2) \
- Entry(n1); \
- Entry(n2); \
- FRAME
-
-#define NONLEAF_RET \
- EMARF; \
- 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_PTR_ARG1(x) mov x, %rsi ;
#define CALL_PANIC() xorb %al,%al ; call EXT(panic) ;
-#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.
- */
-
-/*
- * 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 ; \
- ALIGN_STACK() ; \
- LOAD_STRING_ARG0(2f) ; \
- CALL_PANIC() ; \
- hlt ; \
- .data ; \
-2: String "not a mutex!" ; \
- .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 MACH_RT
-#define CHECK_PREEMPTION_LEVEL() \
- cmpl $0,%gs:CPU_HIBERNATE ; \
- jne 1f ; \
- cmpl $0,%gs:CPU_PREEMPTION_LEVEL ; \
- je 1f ; \
- ALIGN_STACK() ; \
- movl %gs:CPU_PREEMPTION_LEVEL, %eax ; \
- LOAD_ARG1(%eax) ; \
- LOAD_STRING_ARG0(2f) ; \
- CALL_PANIC() ; \
- hlt ; \
- .data ; \
-2: String "preemption_level(%d) != 0!" ; \
- .text ; \
-1:
-#else /* MACH_RT */
-#define CHECK_PREEMPTION_LEVEL()
-#endif /* MACH_RT */
-
-#define CHECK_MYLOCK(current, owner) \
- cmp current, owner ; \
- jne 1f ; \
- ALIGN_STACK() ; \
- LOAD_STRING_ARG0(2f) ; \
- CALL_PANIC() ; \
- hlt ; \
- .data ; \
-2: String "Attempt to recursively lock a non-recursive lock"; \
- .text ; \
-1:
-
-#else /* MACH_LDEBUG */
-#define CHECK_MUTEX_TYPE()
-#define CHECK_PREEMPTION_LEVEL()
-#define CHECK_MYLOCK(thd)
-#endif /* MACH_LDEBUG */
-
#define PREEMPTION_DISABLE \
incl %gs:CPU_PREEMPTION_LEVEL
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"
- */
-
-#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 */
-
-#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
*/
-
-/*
- * void hw_lock_init(hw_lock_t)
- *
- * Initialize a hardware lock.
- */
-LEAF_ENTRY(hw_lock_init)
- movq $0, (%rdi) /* clear the lock */
- LEAF_RET
-
/*
* void hw_lock_byte_init(volatile uint8_t *)
movb $0, (%rdi) /* clear the lock */
LEAF_RET
-/*
- * void hw_lock_lock(hw_lock_t)
- *
- * Acquire lock, spinning until it becomes available.
- * MACH_RT: also return with preemption disabled.
- */
-LEAF_ENTRY(hw_lock_lock)
- mov %gs:CPU_ACTIVE_THREAD, %rcx /* get thread pointer */
-
- PREEMPTION_DISABLE
-1:
- mov (%rdi), %rax
- test %rax,%rax /* lock locked? */
- jne 3f /* branch if so */
- lock; cmpxchg %rcx,(%rdi) /* 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 */
-
/*
* 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.
+ * return with preemption disabled.
*/
LEAF_ENTRY(hw_lock_byte_lock)
PAUSE /* pause for hyper-threading */
jmp 1b /* try again */
-/*
- * 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:
- mov %gs:CPU_ACTIVE_THREAD, %rcx
-
- /*
- * Attempt to grab the lock immediately
- * - fastpath without timeout nonsense.
- */
- PREEMPTION_DISABLE
-
- mov (%rdi), %rax
- test %rax,%rax /* lock locked? */
- jne 2f /* branch if so */
- lock; cmpxchg %rcx,(%rdi) /* try to acquire the HW lock */
- jne 2f /* branch on failure */
- movl $1,%eax
- LEAF_RET
-
-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.
- */
- 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 */
-
-4:
- /*
- * The inner-loop spin to look for the lock being freed.
- */
- mov $(INNER_LOOP_COUNT),%r9
-5:
- PAUSE /* pause for hyper-threading */
- mov (%rdi),%rax /* spin checking lock value in cache */
- test %rax,%rax
- je 6f /* zero => unlocked, try to grab it */
- decq %r9 /* decrement inner loop count */
- jnz 5b /* time to check for timeout? */
-
- /*
- * Here after spinning INNER_LOOP_COUNT times, check for timeout
- */
- 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
- LEAF_RET
-
-6:
- /*
- * Here to try to grab the lock that now appears to be free
- * after contention.
- */
- mov %gs:CPU_ACTIVE_THREAD, %rcx
- lock; cmpxchg %rcx,(%rdi) /* try to acquire the HW lock */
- jne 4b /* no - spin again */
- movl $1,%eax /* yes */
- pop %r9
- LEAF_RET
-
-/*
- * void hw_lock_unlock(hw_lock_t)
- *
- * Unconditionally release lock.
- * MACH_RT: release preemption level.
- */
-LEAF_ENTRY(hw_lock_unlock)
- movq $0, (%rdi) /* clear the lock */
- PREEMPTION_ENABLE
- LEAF_RET
-
/*
* void hw_lock_byte_unlock(uint8_t *lock_byte)
*
- * Unconditionally release byte sized lock operand.
- * MACH_RT: release preemption level.
+ * Unconditionally release byte sized lock operand,
+ * release preemption level.
*/
LEAF_ENTRY(hw_lock_byte_unlock)
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)
- mov %gs:CPU_ACTIVE_THREAD, %rcx
- PREEMPTION_DISABLE
-
- mov (%rdi),%rax
- test %rax,%rax
- jne 1f
- lock; cmpxchg %rcx,(%rdi) /* try to acquire the HW lock */
- jne 1f
-
- movl $1,%eax /* success */
- LEAF_RET
-
-1:
- PREEMPTION_ENABLE /* failure: release preemption... */
- xorl %eax,%eax /* ...and return failure */
- LEAF_RET
-
-/*
- * unsigned int hw_lock_held(hw_lock_t)
- * MACH_RT: doesn't change preemption state.
- * N.B. Racy, of course.
- */
-LEAF_ENTRY(hw_lock_held)
- mov (%rdi),%rax /* check lock value */
- test %rax,%rax
- movl $1,%ecx
- cmovne %ecx,%eax /* 0 => unlocked, 1 => locked */
- LEAF_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)
-
-#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
- */
-
-#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)
- mov %gs:CPU_ACTIVE_THREAD, %rcx /* Load thread pointer */
- incl TH_RWLOCK_COUNT(%rcx) /* Increment count before atomic CAS */
-1:
- mov (%rdi), %eax /* Load state bitfield and interlock */
- testl $(RW_LOCK_SHARED_MASK), %eax /* Eligible for fastpath? */
- jne 3f
-
- movl %eax, %ecx /* original value in %eax for cmpxchgl */
- incl %ecx /* Increment reader refcount */
- lock
- cmpxchgl %ecx, (%rdi) /* 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
- /*
- Fall thru when patched, counting on lock pointer in %rdi
- */
- LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_ACQUIRE, %rdi)
-#endif
- ret
-2:
- PAUSE
- jmp 1b
-3:
- jmp EXT(lck_rw_lock_shared_gen)
-
-
-
-#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)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* Attempt atomic exchange */
- jne 2f
-
- mov %gs:CPU_ACTIVE_THREAD, %rcx /* Load thread pointer */
- incl TH_RWLOCK_COUNT(%rcx) /* Increment count on success. */
- /* There is a 3 instr window where preemption may not notice rwlock_count after cmpxchg */
-
-#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 %rdi */
- LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, %rdi)
-#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)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* Attempt atomic exchange */
- jne 4f
-
- movl $1, %eax /* return success */
- ret
-3:
- testl $(LCK_RW_SHARED_MASK), %eax
- je 4f
- testl $(LCK_RW_PRIV_EXCL), %eax
- je 2b
-4:
- xorl %eax, %eax /* return failure */
- ret
-5:
- PAUSE
- jmp 1b
-
-
-
-#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)
- mov %gs:CPU_ACTIVE_THREAD, %rcx /* Load thread pointer */
- incl TH_RWLOCK_COUNT(%rcx) /* Increment count before atomic CAS */
-1:
- mov (%rdi), %eax /* Load state bitfield, interlock and shared count */
- testl $(RW_LOCK_EXCLUSIVE_MASK), %eax /* Eligible for fastpath? */
- jne 3f /* no, go slow */
-
- movl %eax, %ecx /* original value in %eax for cmpxchgl */
- orl $(LCK_RW_WANT_WRITE), %ecx
- lock
- cmpxchgl %ecx, (%rdi) /* 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 %rdi */
- LOCKSTAT_RECORD(LS_LCK_RW_LOCK_EXCL_ACQUIRE, %rdi)
-#endif
- ret
-2:
- PAUSE
- jmp 1b
-3:
- jmp EXT(lck_rw_lock_exclusive_gen)
-
-
-
-#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)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* Attempt atomic exchange */
- jne 2f
-
- mov %gs:CPU_ACTIVE_THREAD, %rcx /* Load thread pointer */
- incl TH_RWLOCK_COUNT(%rcx) /* Increment count on success. */
- /* There is a 3 instr window where preemption may not notice rwlock_count after cmpxchg */
-
-#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 %rdi */
- LOCKSTAT_RECORD(LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, %rdi)
-#endif
- movl $1, %eax /* return TRUE */
- ret
-2:
- PAUSE
- jmp 1b
-3:
- xorl %eax, %eax /* return FALSE */
- ret
-
-
-
-/*
- * 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)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* 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 %rdi */
- LOCKSTAT_RECORD(LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, %rdi)
-#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, (%rdi) /* Attempt atomic exchange */
- jne 7f
-
- mov %eax, %esi /* put old flags as second arg */
- /* lock is alread in %rdi */
- call EXT(lck_rw_lock_shared_to_exclusive_failure)
- ret /* and pass the failure return along */
-7:
- PAUSE
- jmp 1b
-8:
- jmp EXT(lck_rw_lock_shared_to_exclusive_success)
-
-
-
- .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)
-1:
- mov (%rdi), %eax /* 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
- 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
-
- testl $(LCK_RW_PRIV_EXCL), %eax
- jne 6f
-5:
- andl $(~LCK_R_WAITING), %ecx
-6:
- lock
- cmpxchgl %ecx, (%rdi) /* Attempt atomic exchange */
- jne 7f
-
- mov %eax,%esi /* old flags in %rsi */
- /* lock is in %rdi already */
- call EXT(lck_rw_done_gen)
- ret
-7:
- PAUSE
- jmp 1b
-8:
- ALIGN_STACK()
- LOAD_STRING_ARG0(rwl_release_error_str)
- CALL_PANIC()
-
-
-
-/*
- * lck_rw_type_t lck_rw_lock_exclusive_to_shared(lck_rw_t *)
- *
- */
-Entry(lck_rw_lock_exclusive_to_shared)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* Attempt atomic exchange */
- jne 6f
-
- mov %eax,%esi
- call EXT(lck_rw_lock_exclusive_to_shared_gen)
- ret
-6:
- PAUSE
- jmp 1b
-
-
-
-/*
- * int lck_rw_grab_want(lck_rw_t *)
- *
- */
-Entry(lck_rw_grab_want)
-1:
- mov (%rdi), %eax /* 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, (%rdi) /* 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)
- mov (%rdi), %eax
- 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
-
-
-#define LMTX_ENTER_EXTENDED \
- mov M_PTR(%rdx), %rdx ; \
- xor %r11, %r11 ; \
- mov MUTEX_GRP(%rdx), %r10 ; \
- LOCK_IF_ATOMIC_STAT_UPDATES ; \
- incq GRP_MTX_STAT_UTIL(%r10)
-
-
-#if LOG_FIRST_MISS_ALONE
-#define LMTX_UPDATE_MISS \
- test $1, %r11 ; \
- jnz 11f ; \
- LOCK_IF_ATOMIC_STAT_UPDATES ; \
- incl GRP_MTX_STAT_MISS(%r10) ; \
- or $1, %r11 ; \
-11:
-#else
-#define LMTX_UPDATE_MISS \
- LOCK_IF_ATOMIC_STAT_UPDATES ; \
- incl GRP_MTX_STAT_MISS(%r10)
-#endif
-
-
-#if LOG_FIRST_MISS_ALONE
-#define LMTX_UPDATE_WAIT \
- test $2, %r11 ; \
- jnz 11f ; \
- LOCK_IF_ATOMIC_STAT_UPDATES ; \
- incl GRP_MTX_STAT_WAIT(%r10) ; \
- or $2, %r11 ; \
-11:
-#else
-#define LMTX_UPDATE_WAIT \
- LOCK_IF_ATOMIC_STAT_UPDATES ; \
- incl GRP_MTX_STAT_WAIT(%r10)
-#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(%r10)
-
-
-#define LMTX_CALLEXT1(func_name) \
- cmp %rdx, %rdi ; \
- je 12f ; \
- push %r10 ; \
- push %r11 ; \
-12: push %rdi ; \
- push %rdx ; \
- mov %rdx, %rdi ; \
- call EXT(func_name) ; \
- pop %rdx ; \
- pop %rdi ; \
- cmp %rdx, %rdi ; \
- je 12f ; \
- pop %r11 ; \
- pop %r10 ; \
-12:
-
-#define LMTX_CALLEXT2(func_name, reg) \
- cmp %rdx, %rdi ; \
- je 12f ; \
- push %r10 ; \
- push %r11 ; \
-12: push %rdi ; \
- push %rdx ; \
- mov reg, %rsi ; \
- mov %rdx, %rdi ; \
- call EXT(func_name) ; \
- pop %rdx ; \
- pop %rdi ; \
- cmp %rdx, %rdi ; \
- je 12f ; \
- pop %r11 ; \
- pop %r10 ; \
-12:
-
-
-#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)
- mov %rdi, %rdx /* Load lock address */
- mov %gs:CPU_ACTIVE_THREAD, %rax /* Load current thread */
-
- mov M_STATE(%rdx), %ecx
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne 0f
- mov M_PTR(%rdx), %rdx /* If so, take indirection */
-0:
- mov M_OWNER(%rdx), %rcx /* Load owner */
- cmp $(MUTEX_ASSERT_OWNED), %rsi
- jne 2f /* Assert ownership? */
- cmp %rax, %rcx /* Current thread match? */
- jne 3f /* no, go panic */
- testl $(M_ILOCKED_MSK | M_MLOCKED_MSK), M_STATE(%rdx)
- je 3f
-1: /* yes, we own it */
- NONLEAF_RET
-2:
- cmp %rax, %rcx /* Current thread match? */
- jne 1b /* No, return */
- ALIGN_STACK()
- LOAD_PTR_ARG1(%rdx)
- LOAD_STRING_ARG0(mutex_assert_owned_str)
- jmp 4f
-3:
- ALIGN_STACK()
- LOAD_PTR_ARG1(%rdx)
- LOAD_STRING_ARG0(mutex_assert_not_owned_str)
-4:
- CALL_PANIC()
-
-
-lck_mtx_destroyed:
- ALIGN_STACK()
- LOAD_PTR_ARG1(%rdx)
- 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_try_lock_spin()
- * lck_mtx_try_lock_spin_always()
- * lck_mtx_convert_spin()
- */
-NONLEAF_ENTRY(lck_mtx_lock_spin_always)
- mov %rdi, %rdx /* fetch lock pointer */
- jmp Llmls_avoid_check
-
-NONLEAF_ENTRY(lck_mtx_lock_spin)
- mov %rdi, %rdx /* fetch lock pointer */
-
- CHECK_PREEMPTION_LEVEL()
-Llmls_avoid_check:
- mov M_STATE(%rdx), %ecx
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx /* is the interlock or mutex held */
- jnz Llmls_slow
-Llmls_try: /* no - can't be INDIRECT, DESTROYED or locked */
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK | M_SPIN_MSK), %ecx
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne Llmls_busy_disabled
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of interlock */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- /* 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 %rdx above */
- LOCKSTAT_RECORD(LS_LCK_MTX_LOCK_SPIN_ACQUIRE, %rdx)
-#endif
- ret
-
-Llmls_slow:
- test $M_ILOCKED_MSK, %ecx /* is the interlock held */
- jz Llml_contended /* no, must have been the mutex */
-
- cmp $(MUTEX_DESTROYED), %ecx /* check to see if its marked destroyed */
- je lck_mtx_destroyed
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex */
- jne Llmls_loop /* no... must be interlocked */
-
- LMTX_ENTER_EXTENDED
-
- mov M_STATE(%rdx), %ecx
- test $(M_SPIN_MSK), %ecx
- jz Llmls_loop1
-
- LMTX_UPDATE_MISS /* M_SPIN_MSK was set, so M_ILOCKED_MSK must also be present */
-Llmls_loop:
- PAUSE
- mov M_STATE(%rdx), %ecx
-Llmls_loop1:
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx
- jz Llmls_try
- test $(M_MLOCKED_MSK), %ecx
- jnz Llml_contended /* mutex owned by someone else, go contend for it */
- jmp Llmls_loop
-
-Llmls_busy_disabled:
- PREEMPTION_ENABLE
- jmp Llmls_loop
-
-
-
-NONLEAF_ENTRY(lck_mtx_lock)
- mov %rdi, %rdx /* fetch lock pointer */
-
- CHECK_PREEMPTION_LEVEL()
-
- mov M_STATE(%rdx), %ecx
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx /* is the interlock or mutex held */
- jnz Llml_slow
-Llml_try: /* no - can't be INDIRECT, DESTROYED or locked */
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne Llml_busy_disabled
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of mutex */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- testl $(M_WAITERS_MSK), M_STATE(%rdx)
- jz Llml_finish
-
- LMTX_CALLEXT1(lck_mtx_lock_acquire_x86)
-
-Llml_finish:
- andl $(~M_ILOCKED_MSK), M_STATE(%rdx)
- PREEMPTION_ENABLE
-
- cmp %rdx, %rdi /* is this an extended mutex */
- jne 2f
-
- leave
-#if CONFIG_DTRACE
- LOCKSTAT_LABEL(_lck_mtx_lock_lockstat_patch_point)
- ret
- /* inherit lock pointer in %rdx above */
- LOCKSTAT_RECORD(LS_LCK_MTX_LOCK_ACQUIRE, %rdx)
-#endif
- ret
-2:
- leave
-#if CONFIG_DTRACE
- LOCKSTAT_LABEL(_lck_mtx_lock_ext_lockstat_patch_point)
- ret
- /* inherit lock pointer in %rdx above */
- LOCKSTAT_RECORD(LS_LCK_MTX_EXT_LOCK_ACQUIRE, %rdx)
-#endif
- ret
-
-
-Llml_slow:
- test $M_ILOCKED_MSK, %ecx /* is the interlock held */
- jz Llml_contended /* no, must have been the mutex */
-
- cmp $(MUTEX_DESTROYED), %ecx /* check to see if its marked destroyed */
- je lck_mtx_destroyed
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne Llml_loop /* no... must be interlocked */
-
- LMTX_ENTER_EXTENDED
-
- mov M_STATE(%rdx), %ecx
- test $(M_SPIN_MSK), %ecx
- 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(%rdx), %ecx
-Llml_loop1:
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx
- jz Llml_try
- test $(M_MLOCKED_MSK), %ecx
- 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:
- cmp %rdx, %rdi /* is this an extended mutex */
- je 0f
- LMTX_UPDATE_MISS
-0:
- LMTX_CALLEXT1(lck_mtx_lock_spinwait_x86)
-
- test %rax, %rax
- jz Llml_acquired /* acquired mutex, interlock held and preemption disabled */
-
- cmp $1, %rax /* check for direct wait status */
- je 2f
- cmp %rdx, %rdi /* is this an extended mutex */
- je 2f
- LMTX_UPDATE_DIRECT_WAIT
-2:
- mov M_STATE(%rdx), %ecx
- test $(M_ILOCKED_MSK), %ecx
- jnz 6f
-
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK), %ecx /* try to take the interlock */
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne 5f
-
- test $(M_MLOCKED_MSK), %ecx /* we've got the interlock and */
- jnz 3f
- or $(M_MLOCKED_MSK), %ecx /* the mutex is free... grab it directly */
- mov %ecx, M_STATE(%rdx)
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of mutex */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
-Llml_acquired:
- testl $(M_WAITERS_MSK), M_STATE(%rdx)
- jnz 1f
- mov M_OWNER(%rdx), %rax
- mov TH_WAS_PROMOTED_ON_WAKEUP(%rax), %eax
- test %eax, %eax
- jz Llml_finish
-1:
- LMTX_CALLEXT1(lck_mtx_lock_acquire_x86)
- jmp Llml_finish
-
-3: /* interlock held, mutex busy */
- cmp %rdx, %rdi /* 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_always)
- mov %rdi, %rdx /* fetch lock pointer */
- jmp Llmts_avoid_check
-
-NONLEAF_ENTRY(lck_mtx_try_lock_spin)
- mov %rdi, %rdx /* fetch lock pointer */
-
-Llmts_avoid_check:
- mov M_STATE(%rdx), %ecx
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx /* is the interlock or mutex held */
- jnz Llmts_slow
-Llmts_try: /* no - can't be INDIRECT, DESTROYED or locked */
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK | M_SPIN_MSK), %rcx
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne Llmts_busy_disabled
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of mutex */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- leave
-
-#if CONFIG_DTRACE
- mov $1, %rax /* return success */
- LOCKSTAT_LABEL(_lck_mtx_try_lock_spin_lockstat_patch_point)
- ret
- /* inherit lock pointer in %rdx above */
- LOCKSTAT_RECORD(LS_LCK_MTX_TRY_SPIN_LOCK_ACQUIRE, %rdx)
-#endif
- mov $1, %rax /* return success */
- ret
-
-Llmts_slow:
- test $(M_ILOCKED_MSK), %ecx /* is the interlock held */
- jz Llmts_fail /* no, must be held as a mutex */
-
- cmp $(MUTEX_DESTROYED), %ecx /* check to see if its marked destroyed */
- je lck_mtx_destroyed
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne Llmts_loop1
-
- LMTX_ENTER_EXTENDED
-Llmts_loop:
- PAUSE
- mov M_STATE(%rdx), %ecx
-Llmts_loop1:
- test $(M_MLOCKED_MSK | M_SPIN_MSK), %ecx
- jnz Llmts_fail
- test $(M_ILOCKED_MSK), %ecx
- jz Llmts_try
- jmp Llmts_loop
-
-Llmts_busy_disabled:
- PREEMPTION_ENABLE
- jmp Llmts_loop
-
-
-
-NONLEAF_ENTRY(lck_mtx_try_lock)
- mov %rdi, %rdx /* fetch lock pointer */
-
- mov M_STATE(%rdx), %ecx
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx /* is the interlock or mutex held */
- jnz Llmt_slow
-Llmt_try: /* no - can't be INDIRECT, DESTROYED or locked */
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne Llmt_busy_disabled
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of mutex */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- test $(M_WAITERS_MSK), %ecx
- jz 0f
-
- LMTX_CALLEXT1(lck_mtx_lock_acquire_x86)
-0:
- andl $(~M_ILOCKED_MSK), M_STATE(%rdx)
- PREEMPTION_ENABLE
-
- leave
-#if CONFIG_DTRACE
- mov $1, %rax /* return success */
- /* Dtrace probe: LS_LCK_MTX_TRY_LOCK_ACQUIRE */
- LOCKSTAT_LABEL(_lck_mtx_try_lock_lockstat_patch_point)
- ret
- /* inherit lock pointer in %rdx from above */
- LOCKSTAT_RECORD(LS_LCK_MTX_TRY_LOCK_ACQUIRE, %rdx)
-#endif
- mov $1, %rax /* return success */
- ret
-
-Llmt_slow:
- test $(M_ILOCKED_MSK), %ecx /* is the interlock held */
- jz Llmt_fail /* no, must be held as a mutex */
-
- cmp $(MUTEX_DESTROYED), %ecx /* check to see if its marked destroyed */
- je lck_mtx_destroyed
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne Llmt_loop
-
- LMTX_ENTER_EXTENDED
-Llmt_loop:
- PAUSE
- mov M_STATE(%rdx), %ecx
-Llmt_loop1:
- test $(M_MLOCKED_MSK | M_SPIN_MSK), %ecx
- jnz Llmt_fail
- test $(M_ILOCKED_MSK), %ecx
- jz Llmt_try
- jmp Llmt_loop
-
-Llmt_busy_disabled:
- PREEMPTION_ENABLE
- jmp Llmt_loop
-
-
-Llmt_fail:
-Llmts_fail:
- cmp %rdx, %rdi /* is this an extended mutex */
- je 0f
- LMTX_UPDATE_MISS
-0:
- xor %rax, %rax
- NONLEAF_RET
-
-
-
-NONLEAF_ENTRY(lck_mtx_convert_spin)
- mov %rdi, %rdx /* fetch lock pointer */
-
- mov M_STATE(%rdx), %ecx
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne 0f
- mov M_PTR(%rdx), %rdx /* If so, take indirection */
- mov M_STATE(%rdx), %ecx
-0:
- test $(M_MLOCKED_MSK), %ecx /* already owned as a mutex, just return */
- jnz 2f
- test $(M_WAITERS_MSK), %ecx /* are there any waiters? */
- jz 1f
-
- LMTX_CALLEXT1(lck_mtx_lock_acquire_x86)
- mov M_STATE(%rdx), %ecx
-1:
- and $(~(M_ILOCKED_MSK | M_SPIN_MSK)), %ecx /* convert from spin version to mutex */
- or $(M_MLOCKED_MSK), %ecx
- mov %ecx, M_STATE(%rdx) /* since I own the interlock, I don't need an atomic update */
-
- PREEMPTION_ENABLE
-2:
- NONLEAF_RET
-
-
-
-NONLEAF_ENTRY(lck_mtx_unlock)
- mov %rdi, %rdx /* fetch lock pointer */
-Llmu_entry:
- mov M_STATE(%rdx), %ecx
-Llmu_prim:
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- je Llmu_ext
-
-Llmu_chktype:
- test $(M_MLOCKED_MSK), %ecx /* check for full mutex */
- jz Llmu_unlock
-Llmu_mutex:
- test $(M_ILOCKED_MSK), %rcx /* have to wait for interlock to clear */
- jnz Llmu_busy
-
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- and $(~M_MLOCKED_MSK), %ecx /* drop mutex */
- or $(M_ILOCKED_MSK), %ecx /* pick up interlock */
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne Llmu_busy_disabled /* branch on failure to spin loop */
-
-Llmu_unlock:
- xor %rax, %rax
- mov %rax, M_OWNER(%rdx)
- mov %rcx, %rax /* keep original state in %ecx for later evaluation */
- and $(~(M_ILOCKED_MSK | M_SPIN_MSK | M_PROMOTED_MSK)), %rax
-
- test $(M_WAITERS_MSK), %eax
- jz 2f
- dec %eax /* decrement waiter count */
-2:
- mov %eax, M_STATE(%rdx) /* 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, %rax
- test %rax, %rax
- jz 1f
- decl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- test $(M_PROMOTED_MSK | M_WAITERS_MSK), %ecx
- jz 3f
-
- LMTX_CALLEXT2(lck_mtx_unlock_wakeup_x86, %rcx)
-3:
- PREEMPTION_ENABLE
-
- cmp %rdx, %rdi
- 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 %rdx from above */
- LOCKSTAT_RECORD(LS_LCK_MTX_UNLOCK_RELEASE, %rdx)
-#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 %rdx from above */
- LOCKSTAT_RECORD(LS_LCK_MTX_EXT_UNLOCK_RELEASE, %rdx)
-#endif
- ret
-
-
-Llmu_busy_disabled:
- PREEMPTION_ENABLE
-Llmu_busy:
- PAUSE
- mov M_STATE(%rdx), %ecx
- jmp Llmu_mutex
-
-Llmu_ext:
- mov M_PTR(%rdx), %rdx
- mov M_OWNER(%rdx), %rax
- mov %gs:CPU_ACTIVE_THREAD, %rcx
- CHECK_UNLOCK(%rcx, %rax)
- mov M_STATE(%rdx), %ecx
- jmp Llmu_chktype
-
-
-
-LEAF_ENTRY(lck_mtx_ilk_unlock)
- mov %rdi, %rdx /* fetch lock pointer - no indirection here */
-
- andl $(~M_ILOCKED_MSK), M_STATE(%rdx)
-
- PREEMPTION_ENABLE /* need to re-enable preemption */
-
- LEAF_RET
-
-
-
-LEAF_ENTRY(lck_mtx_lock_grab_mutex)
- mov %rdi, %rdx /* fetch lock pointer - no indirection here */
-
- mov M_STATE(%rdx), %ecx
-
- test $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx /* can't have the mutex yet */
- jnz 3f
-
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK | M_MLOCKED_MSK), %ecx
-
- PREEMPTION_DISABLE
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne 2f /* branch on failure to spin loop */
-
- mov %gs:CPU_ACTIVE_THREAD, %rax
- mov %rax, M_OWNER(%rdx) /* record owner of mutex */
-#if MACH_LDEBUG
- test %rax, %rax
- jz 1f
- incl TH_MUTEX_COUNT(%rax) /* lock statistic */
-1:
-#endif /* MACH_LDEBUG */
-
- mov $1, %rax /* return success */
- LEAF_RET
-2:
- PREEMPTION_ENABLE
-3:
- xor %rax, %rax /* return failure */
- LEAF_RET
-
-
-
-LEAF_ENTRY(lck_mtx_lock_mark_destroyed)
- mov %rdi, %rdx
-1:
- mov M_STATE(%rdx), %ecx
- cmp $(MUTEX_IND), %ecx /* Is this an indirect mutex? */
- jne 2f
-
- movl $(MUTEX_DESTROYED), M_STATE(%rdx) /* convert to destroyed state */
- jmp 3f
-2:
- test $(M_ILOCKED_MSK), %rcx /* have to wait for interlock to clear */
- jnz 5f
-
- PREEMPTION_DISABLE
- mov %rcx, %rax /* eax contains snapshot for cmpxchgl */
- or $(M_ILOCKED_MSK), %ecx
- lock
- cmpxchg %ecx, M_STATE(%rdx) /* atomic compare and exchange */
- jne 4f /* branch on failure to spin loop */
- movl $(MUTEX_DESTROYED), M_STATE(%rdx) /* 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
16: String "Preemption level underflow, possible cause unlocking an unlocked mutex or spinlock"
.text
-
-LEAF_ENTRY(_disable_preemption)
-#if MACH_RT
- PREEMPTION_DISABLE
-#endif /* MACH_RT */
- LEAF_RET
-
-LEAF_ENTRY(_enable_preemption)
-#if MACH_RT
-#if MACH_ASSERT
- cmpl $0,%gs:CPU_PREEMPTION_LEVEL
- jg 1f
- movl %gs:CPU_PREEMPTION_LEVEL,%esi
- ALIGN_STACK()
- LOAD_STRING_ARG0(_enable_preemption_less_than_zero)
- CALL_PANIC()
- hlt
- .cstring
-_enable_preemption_less_than_zero:
- .asciz "_enable_preemption: preemption_level(%d) < 0!"
- .text
-1:
-#endif /* MACH_ASSERT */
- PREEMPTION_ENABLE
-#endif /* MACH_RT */
- LEAF_RET
-
-LEAF_ENTRY(_enable_preemption_no_check)
-#if MACH_RT
-#if MACH_ASSERT
- cmpl $0,%gs:CPU_PREEMPTION_LEVEL
- jg 1f
- ALIGN_STACK()
- LOAD_STRING_ARG0(_enable_preemption_no_check_less_than_zero)
- CALL_PANIC()
- hlt
- .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
-#endif /* MACH_RT */
- LEAF_RET
-
-
-LEAF_ENTRY(_mp_disable_preemption)
-#if MACH_RT
- PREEMPTION_DISABLE
-#endif /* MACH_RT */
- LEAF_RET
-
-LEAF_ENTRY(_mp_enable_preemption)
-#if MACH_RT
-#if MACH_ASSERT
- cmpl $0,%gs:CPU_PREEMPTION_LEVEL
- jg 1f
- movl %gs:CPU_PREEMPTION_LEVEL,%esi
- ALIGN_PANIC()
- LOAD_STRING_ARG0(_mp_enable_preemption_less_than_zero)
- CALL_PANIC()
- hlt
- .cstring
-_mp_enable_preemption_less_than_zero:
- .asciz "_mp_enable_preemption: preemption_level (%d) <= 0!"
- .text
-1:
-#endif /* MACH_ASSERT */
- PREEMPTION_ENABLE
-#endif /* MACH_RT */
- LEAF_RET
-
-LEAF_ENTRY(_mp_enable_preemption_no_check)
-#if MACH_RT
-#if MACH_ASSERT
- cmpl $0,%gs:CPU_PREEMPTION_LEVEL
- jg 1f
- ALIGN_STACK()
- LOAD_STRING_ARG0(_mp_enable_preemption_no_check_less_than_zero)
- CALL_PANIC()
- hlt
- .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
-#endif /* MACH_RT */
- 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
-
projects / apple / xnu.git / blobdiff