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c427f69564
Use try_cmpxchg to avoid the pointless TEST instruction..
And add the (missing) atomic_long_try_cmpxchg*() wrappery.
On x86_64 this gives:
0000000000000710 <mutex_lock>: 0000000000000710 <mutex_lock>:
710: 65 48 8b 14 25 00 00 mov %gs:0x0,%rdx 710: 65 48 8b 14 25 00 00 mov %gs:0x0,%rdx
717: 00 00 717: 00 00
715: R_X86_64_32S current_task 715: R_X86_64_32S current_task
719: 31 c0 xor %eax,%eax 719: 31 c0 xor %eax,%eax
71b: f0 48 0f b1 17 lock cmpxchg %rdx,(%rdi) 71b: f0 48 0f b1 17 lock cmpxchg %rdx,(%rdi)
720: 48 85 c0 test %rax,%rax 720: 75 02 jne 724 <mutex_lock+0x14>
723: 75 02 jne 727 <mutex_lock+0x17> 722: f3 c3 repz retq
725: f3 c3 repz retq 724: eb da jmp 700 <__mutex_lock_slowpath>
727: eb d7 jmp 700 <__mutex_lock_slowpath> 726: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1)
729: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 72d: 00 00 00
On ARM64 this gives:
000000000000638 <mutex_lock>: 0000000000000638 <mutex_lock>:
638: d5384101 mrs x1, sp_el0 638: d5384101 mrs x1, sp_el0
63c: d2800002 mov x2, #0x0 63c: d2800002 mov x2, #0x0
640: f9800011 prfm pstl1strm, [x0] 640: f9800011 prfm pstl1strm, [x0]
644: c85ffc03 ldaxr x3, [x0] 644: c85ffc03 ldaxr x3, [x0]
648: ca020064 eor x4, x3, x2 648: ca020064 eor x4, x3, x2
64c: b5000064 cbnz x4, 658 <mutex_lock+0x20> 64c: b5000064 cbnz x4, 658 <mutex_lock+0x20>
650: c8047c01 stxr w4, x1, [x0] 650: c8047c01 stxr w4, x1, [x0]
654: 35ffff84 cbnz w4, 644 <mutex_lock+0xc> 654: 35ffff84 cbnz w4, 644 <mutex_lock+0xc>
658: b40000c3 cbz x3, 670 <mutex_lock+0x38> 658: b5000043 cbnz x3, 660 <mutex_lock+0x28>
65c: a9bf7bfd stp x29, x30, [sp,#-16]! 65c: d65f03c0 ret
660: 910003fd mov x29, sp 660: a9bf7bfd stp x29, x30, [sp,#-16]!
664: 97ffffef bl 620 <__mutex_lock_slowpath> 664: 910003fd mov x29, sp
668: a8c17bfd ldp x29, x30, [sp],#16 668: 97ffffee bl 620 <__mutex_lock_slowpath>
66c: d65f03c0 ret 66c: a8c17bfd ldp x29, x30, [sp],#16
670: d65f03c0 ret 670: d65f03c0 ret
Reported-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
270 lines
7.9 KiB
C
270 lines
7.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_GENERIC_ATOMIC_LONG_H
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#define _ASM_GENERIC_ATOMIC_LONG_H
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/*
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* Copyright (C) 2005 Silicon Graphics, Inc.
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* Christoph Lameter
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*
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* Allows to provide arch independent atomic definitions without the need to
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* edit all arch specific atomic.h files.
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*/
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#include <asm/types.h>
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/*
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* Suppport for atomic_long_t
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*
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* Casts for parameters are avoided for existing atomic functions in order to
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* avoid issues with cast-as-lval under gcc 4.x and other limitations that the
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* macros of a platform may have.
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*/
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#if BITS_PER_LONG == 64
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typedef atomic64_t atomic_long_t;
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#define ATOMIC_LONG_INIT(i) ATOMIC64_INIT(i)
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#define ATOMIC_LONG_PFX(x) atomic64 ## x
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#define ATOMIC_LONG_TYPE s64
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#else
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typedef atomic_t atomic_long_t;
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#define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i)
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#define ATOMIC_LONG_PFX(x) atomic ## x
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#define ATOMIC_LONG_TYPE int
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#endif
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#define ATOMIC_LONG_READ_OP(mo) \
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static inline long atomic_long_read##mo(const atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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return (long)ATOMIC_LONG_PFX(_read##mo)(v); \
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}
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ATOMIC_LONG_READ_OP()
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ATOMIC_LONG_READ_OP(_acquire)
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#undef ATOMIC_LONG_READ_OP
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#define ATOMIC_LONG_SET_OP(mo) \
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static inline void atomic_long_set##mo(atomic_long_t *l, long i) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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ATOMIC_LONG_PFX(_set##mo)(v, i); \
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}
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ATOMIC_LONG_SET_OP()
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ATOMIC_LONG_SET_OP(_release)
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#undef ATOMIC_LONG_SET_OP
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#define ATOMIC_LONG_ADD_SUB_OP(op, mo) \
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static inline long \
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atomic_long_##op##_return##mo(long i, atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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return (long)ATOMIC_LONG_PFX(_##op##_return##mo)(i, v); \
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}
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ATOMIC_LONG_ADD_SUB_OP(add,)
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ATOMIC_LONG_ADD_SUB_OP(add, _relaxed)
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ATOMIC_LONG_ADD_SUB_OP(add, _acquire)
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ATOMIC_LONG_ADD_SUB_OP(add, _release)
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ATOMIC_LONG_ADD_SUB_OP(sub,)
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ATOMIC_LONG_ADD_SUB_OP(sub, _relaxed)
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ATOMIC_LONG_ADD_SUB_OP(sub, _acquire)
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ATOMIC_LONG_ADD_SUB_OP(sub, _release)
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#undef ATOMIC_LONG_ADD_SUB_OP
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#define atomic_long_cmpxchg_relaxed(l, old, new) \
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(ATOMIC_LONG_PFX(_cmpxchg_relaxed)((ATOMIC_LONG_PFX(_t) *)(l), \
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(old), (new)))
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#define atomic_long_cmpxchg_acquire(l, old, new) \
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(ATOMIC_LONG_PFX(_cmpxchg_acquire)((ATOMIC_LONG_PFX(_t) *)(l), \
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(old), (new)))
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#define atomic_long_cmpxchg_release(l, old, new) \
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(ATOMIC_LONG_PFX(_cmpxchg_release)((ATOMIC_LONG_PFX(_t) *)(l), \
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(old), (new)))
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#define atomic_long_cmpxchg(l, old, new) \
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(ATOMIC_LONG_PFX(_cmpxchg)((ATOMIC_LONG_PFX(_t) *)(l), (old), (new)))
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#define atomic_long_try_cmpxchg_relaxed(l, old, new) \
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(ATOMIC_LONG_PFX(_try_cmpxchg_relaxed)((ATOMIC_LONG_PFX(_t) *)(l), \
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(ATOMIC_LONG_TYPE *)(old), (ATOMIC_LONG_TYPE)(new)))
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#define atomic_long_try_cmpxchg_acquire(l, old, new) \
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(ATOMIC_LONG_PFX(_try_cmpxchg_acquire)((ATOMIC_LONG_PFX(_t) *)(l), \
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(ATOMIC_LONG_TYPE *)(old), (ATOMIC_LONG_TYPE)(new)))
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#define atomic_long_try_cmpxchg_release(l, old, new) \
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(ATOMIC_LONG_PFX(_try_cmpxchg_release)((ATOMIC_LONG_PFX(_t) *)(l), \
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(ATOMIC_LONG_TYPE *)(old), (ATOMIC_LONG_TYPE)(new)))
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#define atomic_long_try_cmpxchg(l, old, new) \
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(ATOMIC_LONG_PFX(_try_cmpxchg)((ATOMIC_LONG_PFX(_t) *)(l), \
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(ATOMIC_LONG_TYPE *)(old), (ATOMIC_LONG_TYPE)(new)))
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#define atomic_long_xchg_relaxed(v, new) \
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(ATOMIC_LONG_PFX(_xchg_relaxed)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
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#define atomic_long_xchg_acquire(v, new) \
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(ATOMIC_LONG_PFX(_xchg_acquire)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
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#define atomic_long_xchg_release(v, new) \
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(ATOMIC_LONG_PFX(_xchg_release)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
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#define atomic_long_xchg(v, new) \
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(ATOMIC_LONG_PFX(_xchg)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
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static __always_inline void atomic_long_inc(atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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ATOMIC_LONG_PFX(_inc)(v);
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}
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static __always_inline void atomic_long_dec(atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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ATOMIC_LONG_PFX(_dec)(v);
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}
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#define ATOMIC_LONG_FETCH_OP(op, mo) \
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static inline long \
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atomic_long_fetch_##op##mo(long i, atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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return (long)ATOMIC_LONG_PFX(_fetch_##op##mo)(i, v); \
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}
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ATOMIC_LONG_FETCH_OP(add, )
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ATOMIC_LONG_FETCH_OP(add, _relaxed)
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ATOMIC_LONG_FETCH_OP(add, _acquire)
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ATOMIC_LONG_FETCH_OP(add, _release)
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ATOMIC_LONG_FETCH_OP(sub, )
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ATOMIC_LONG_FETCH_OP(sub, _relaxed)
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ATOMIC_LONG_FETCH_OP(sub, _acquire)
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ATOMIC_LONG_FETCH_OP(sub, _release)
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ATOMIC_LONG_FETCH_OP(and, )
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ATOMIC_LONG_FETCH_OP(and, _relaxed)
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ATOMIC_LONG_FETCH_OP(and, _acquire)
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ATOMIC_LONG_FETCH_OP(and, _release)
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ATOMIC_LONG_FETCH_OP(andnot, )
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ATOMIC_LONG_FETCH_OP(andnot, _relaxed)
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ATOMIC_LONG_FETCH_OP(andnot, _acquire)
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ATOMIC_LONG_FETCH_OP(andnot, _release)
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ATOMIC_LONG_FETCH_OP(or, )
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ATOMIC_LONG_FETCH_OP(or, _relaxed)
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ATOMIC_LONG_FETCH_OP(or, _acquire)
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ATOMIC_LONG_FETCH_OP(or, _release)
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ATOMIC_LONG_FETCH_OP(xor, )
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ATOMIC_LONG_FETCH_OP(xor, _relaxed)
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ATOMIC_LONG_FETCH_OP(xor, _acquire)
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ATOMIC_LONG_FETCH_OP(xor, _release)
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#undef ATOMIC_LONG_FETCH_OP
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#define ATOMIC_LONG_FETCH_INC_DEC_OP(op, mo) \
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static inline long \
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atomic_long_fetch_##op##mo(atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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return (long)ATOMIC_LONG_PFX(_fetch_##op##mo)(v); \
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}
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ATOMIC_LONG_FETCH_INC_DEC_OP(inc,)
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ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _relaxed)
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ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _acquire)
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ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _release)
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ATOMIC_LONG_FETCH_INC_DEC_OP(dec,)
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ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _relaxed)
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ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _acquire)
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ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _release)
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#undef ATOMIC_LONG_FETCH_INC_DEC_OP
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#define ATOMIC_LONG_OP(op) \
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static __always_inline void \
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atomic_long_##op(long i, atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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ATOMIC_LONG_PFX(_##op)(i, v); \
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}
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ATOMIC_LONG_OP(add)
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ATOMIC_LONG_OP(sub)
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ATOMIC_LONG_OP(and)
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ATOMIC_LONG_OP(andnot)
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ATOMIC_LONG_OP(or)
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ATOMIC_LONG_OP(xor)
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#undef ATOMIC_LONG_OP
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static inline int atomic_long_sub_and_test(long i, atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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return ATOMIC_LONG_PFX(_sub_and_test)(i, v);
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}
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static inline int atomic_long_dec_and_test(atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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return ATOMIC_LONG_PFX(_dec_and_test)(v);
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}
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static inline int atomic_long_inc_and_test(atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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return ATOMIC_LONG_PFX(_inc_and_test)(v);
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}
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static inline int atomic_long_add_negative(long i, atomic_long_t *l)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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return ATOMIC_LONG_PFX(_add_negative)(i, v);
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}
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#define ATOMIC_LONG_INC_DEC_OP(op, mo) \
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static inline long \
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atomic_long_##op##_return##mo(atomic_long_t *l) \
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{ \
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
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\
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return (long)ATOMIC_LONG_PFX(_##op##_return##mo)(v); \
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}
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ATOMIC_LONG_INC_DEC_OP(inc,)
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ATOMIC_LONG_INC_DEC_OP(inc, _relaxed)
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ATOMIC_LONG_INC_DEC_OP(inc, _acquire)
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ATOMIC_LONG_INC_DEC_OP(inc, _release)
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ATOMIC_LONG_INC_DEC_OP(dec,)
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ATOMIC_LONG_INC_DEC_OP(dec, _relaxed)
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ATOMIC_LONG_INC_DEC_OP(dec, _acquire)
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ATOMIC_LONG_INC_DEC_OP(dec, _release)
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#undef ATOMIC_LONG_INC_DEC_OP
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static inline long atomic_long_add_unless(atomic_long_t *l, long a, long u)
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{
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ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
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return (long)ATOMIC_LONG_PFX(_add_unless)(v, a, u);
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}
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#define atomic_long_inc_not_zero(l) \
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ATOMIC_LONG_PFX(_inc_not_zero)((ATOMIC_LONG_PFX(_t) *)(l))
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#define atomic_long_cond_read_relaxed(v, c) \
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ATOMIC_LONG_PFX(_cond_read_relaxed)((ATOMIC_LONG_PFX(_t) *)(v), (c))
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#define atomic_long_cond_read_acquire(v, c) \
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ATOMIC_LONG_PFX(_cond_read_acquire)((ATOMIC_LONG_PFX(_t) *)(v), (c))
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#endif /* _ASM_GENERIC_ATOMIC_LONG_H */
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