2019-05-26 23:55:01 -07:00
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// SPDX-License-Identifier: GPL-2.0-or-later
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2009-06-12 14:10:05 -07:00
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/*
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* Generic implementation of 64-bit atomics using spinlocks,
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* useful on processors that don't have 64-bit atomic instructions.
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*
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* Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*/
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#include <linux/types.h>
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#include <linux/cache.h>
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#include <linux/spinlock.h>
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#include <linux/init.h>
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2011-11-16 19:29:17 -07:00
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#include <linux/export.h>
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2011-07-26 16:09:06 -07:00
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#include <linux/atomic.h>
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2009-06-12 14:10:05 -07:00
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/*
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* We use a hashed array of spinlocks to provide exclusive access
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* to each atomic64_t variable. Since this is expected to used on
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* systems with small numbers of CPUs (<= 4 or so), we use a
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* relatively small array of 16 spinlocks to avoid wasting too much
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* memory on the spinlock array.
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*/
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#define NR_LOCKS 16
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/*
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* Ensure each lock is in a separate cacheline.
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*/
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static union {
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2011-08-31 20:32:03 -07:00
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raw_spinlock_t lock;
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2009-06-12 14:10:05 -07:00
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char pad[L1_CACHE_BYTES];
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2012-12-20 00:39:48 -07:00
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} atomic64_lock[NR_LOCKS] __cacheline_aligned_in_smp = {
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[0 ... (NR_LOCKS - 1)] = {
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.lock = __RAW_SPIN_LOCK_UNLOCKED(atomic64_lock.lock),
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},
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};
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2009-06-12 14:10:05 -07:00
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2011-09-14 00:49:24 -07:00
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static inline raw_spinlock_t *lock_addr(const atomic64_t *v)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long addr = (unsigned long) v;
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addr >>= L1_CACHE_SHIFT;
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addr ^= (addr >> 8) ^ (addr >> 16);
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return &atomic64_lock[addr & (NR_LOCKS - 1)].lock;
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}
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_read(const atomic64_t *v)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2019-05-22 06:22:35 -07:00
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s64 val;
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2009-06-12 14:10:05 -07:00
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val = v->counter;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2009-06-12 14:10:05 -07:00
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return val;
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_read);
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2009-06-12 14:10:05 -07:00
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2021-05-25 07:02:09 -07:00
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void generic_atomic64_set(atomic64_t *v, s64 i)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2009-06-12 14:10:05 -07:00
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v->counter = i;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2009-06-12 14:10:05 -07:00
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_set);
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2009-06-12 14:10:05 -07:00
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2014-04-23 07:12:30 -07:00
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#define ATOMIC64_OP(op, c_op) \
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2021-05-25 07:02:09 -07:00
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void generic_atomic64_##op(s64 a, atomic64_t *v) \
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2014-04-23 07:12:30 -07:00
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{ \
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unsigned long flags; \
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raw_spinlock_t *lock = lock_addr(v); \
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\
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raw_spin_lock_irqsave(lock, flags); \
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v->counter c_op a; \
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raw_spin_unlock_irqrestore(lock, flags); \
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} \
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_##op);
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2014-04-23 07:12:30 -07:00
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#define ATOMIC64_OP_RETURN(op, c_op) \
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \
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2014-04-23 07:12:30 -07:00
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{ \
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unsigned long flags; \
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raw_spinlock_t *lock = lock_addr(v); \
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2019-05-22 06:22:35 -07:00
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s64 val; \
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2014-04-23 07:12:30 -07:00
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\
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raw_spin_lock_irqsave(lock, flags); \
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val = (v->counter c_op a); \
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raw_spin_unlock_irqrestore(lock, flags); \
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return val; \
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} \
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_##op##_return);
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2014-04-23 07:12:30 -07:00
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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#define ATOMIC64_FETCH_OP(op, c_op) \
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v) \
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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{ \
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unsigned long flags; \
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raw_spinlock_t *lock = lock_addr(v); \
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2019-05-22 06:22:35 -07:00
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s64 val; \
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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\
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raw_spin_lock_irqsave(lock, flags); \
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val = v->counter; \
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v->counter c_op a; \
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raw_spin_unlock_irqrestore(lock, flags); \
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return val; \
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} \
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_fetch_##op);
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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2014-04-23 07:12:30 -07:00
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#define ATOMIC64_OPS(op, c_op) \
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ATOMIC64_OP(op, c_op) \
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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ATOMIC64_OP_RETURN(op, c_op) \
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ATOMIC64_FETCH_OP(op, c_op)
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2014-04-23 07:12:30 -07:00
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ATOMIC64_OPS(add, +=)
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ATOMIC64_OPS(sub, -=)
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#undef ATOMIC64_OPS
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locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-17 15:54:38 -07:00
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#define ATOMIC64_OPS(op, c_op) \
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ATOMIC64_OP(op, c_op) \
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ATOMIC64_FETCH_OP(op, c_op)
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ATOMIC64_OPS(and, &=)
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ATOMIC64_OPS(or, |=)
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ATOMIC64_OPS(xor, ^=)
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#undef ATOMIC64_OPS
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#undef ATOMIC64_FETCH_OP
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2014-04-23 07:12:30 -07:00
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#undef ATOMIC64_OP
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2009-06-12 14:10:05 -07:00
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_dec_if_positive(atomic64_t *v)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2019-05-22 06:22:35 -07:00
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s64 val;
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2009-06-12 14:10:05 -07:00
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val = v->counter - 1;
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if (val >= 0)
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v->counter = val;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2009-06-12 14:10:05 -07:00
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return val;
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_dec_if_positive);
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2009-06-12 14:10:05 -07:00
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2019-05-22 06:22:35 -07:00
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s64 val;
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2009-06-12 14:10:05 -07:00
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val = v->counter;
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if (val == o)
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v->counter = n;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2009-06-12 14:10:05 -07:00
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return val;
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_cmpxchg);
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2009-06-12 14:10:05 -07:00
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_xchg(atomic64_t *v, s64 new)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2019-05-22 06:22:35 -07:00
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s64 val;
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2009-06-12 14:10:05 -07:00
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val = v->counter;
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v->counter = new;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2009-06-12 14:10:05 -07:00
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return val;
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_xchg);
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2009-06-12 14:10:05 -07:00
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2021-05-25 07:02:09 -07:00
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s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
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2009-06-12 14:10:05 -07:00
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{
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unsigned long flags;
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2011-09-14 00:49:24 -07:00
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raw_spinlock_t *lock = lock_addr(v);
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2019-05-22 06:22:35 -07:00
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s64 val;
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2009-06-12 14:10:05 -07:00
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2011-08-31 20:32:03 -07:00
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raw_spin_lock_irqsave(lock, flags);
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2018-06-21 05:13:11 -07:00
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val = v->counter;
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if (val != u)
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2009-06-12 14:10:05 -07:00
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v->counter += a;
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2011-08-31 20:32:03 -07:00
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raw_spin_unlock_irqrestore(lock, flags);
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2018-06-21 05:13:11 -07:00
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return val;
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2009-06-12 14:10:05 -07:00
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}
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2021-05-25 07:02:09 -07:00
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EXPORT_SYMBOL(generic_atomic64_fetch_add_unless);
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